sinopse da feec

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sinopse da feec

SINOPSE DA FEEC
Volume 2 - Issue 2
May - August 2009
FEEC-UNICAMP Academic Bulletin
be viewed as an alternative to the use of techniques
based on the relaxation of quadratic forms. An
extension to cope with guaranteed H∞ attenuation
levels is also given, with proof of asymptotic
convergence to the global optimal controller under
quadratic stability. The efficiency of the proposed
approach in terms of precision and computational
effort is demonstrated by means of numerical
comparisons with other methods from the literature.
Editorial
This is the second issue of the second volume of “SINOPSE
DA FEEC” – the Academic Bulletin of the School of
Electrical and Computer Engineering (FEEC) of the
University of Campinas (Unicamp). In this issue we
summarize the main academic results of FEEC’s faculty
work in the second four-months period of 2009.
The “SINOPSE DA FEEC” is divided into sections that
group abstracts of same type of work: Article in journals,
Article in proceedings, Book editions, Book Chapter,
Scientific Event Organization, Patents, Short course in event,
Master’s dissertations, and Doctoral theses. In each section
the abstracts are sorted by research area, Automation;
Biomedical Engineering; Computer Engineering; Electronic,
Microelectronic, Opto-electronic; Electrical energy; and
Telecommunication, Telematic.
Compiling the results we present the abstracts of thirty six
articles in journals, eighty eight articles in event proceedings,
five book chapters, and two patent registrations. We also
emphasize the edition of three books, and the organization of
one scientific event. Two final sections present the abstracts
of forty two master dissertations and twenty doctoral theses
defended in this period.
Continuous-time systems, H∞ control,
linearmatrix inequality (LMI) relaxations, quadratic
stabilizability, Takagi– Sugeno (T–S) fuzzy systems.
Keywords:
Multi-objective Bayesian Artificial Immune System:
Empirical Evaluation and Comparative Analyses
Pablo A. D. Castro, Fernando José Von Zuben
Journal of Mathematical Modelling and Algorithms - ISSN: 15701166 (Print) 1572-9214 (Onl
v:8 n:2 Jun-2009 pp:151-173 doi: 10.1007/s10852-009-9108-2
Recently, we have proposed a MultiObjective Bayesian Artificial Immune System
(MOBAIS) to deal effectively with building blocks
(high-quality partial solutions coded in the solution
vector) in combinatorial multi-objective problems. By
replacing the mutation and cloning operators with a
probabilistic model, more specifically a Bayesian
network representing the joint distribution of
promising solutions, MOBAIS takes into account the
relationships among the variables of the problem,
avoiding the disruption of already obtained highquality partial solutions. The preliminary results have
indicated that our proposal is able to properly build the
Pareto front. Motivated by this scenario, this paper
better formalizes the proposal and investigates its
usefulness on more challenging problems. In addition,
an important enhancement regarding the Bayesian
network learning was incorporated into the algorithm
in order to speed up its execution. To conclude, we
compare MOBAIS with state-of-the-art algorithms
taking into account quantitative aspects of the Pareto
front found by the algorithms. MOBAIS outperforms
the contenders in terms of the quality of the obtained
solutions and requires an amount of computational
resource inferior or compatible with the contenders..
Abstract:
José Raimundo de Oliveira
FEEC Associate Director
Articles in journal
Automation
Convergent LMI relaxations for quadratic
stabilizability and H∞ control of Takagi-Sugeno
fuzzy systems
Vinícius Foletto Montagner, Ricardo Coração de Leão F. de
Oliveira, Pedro Luis Dias Peres
IEEE Transactions on Fuzzy Systems - ISSN: 1063-6706
v:17 n:4 Aug-2009 pp:863-873 doi: doi:10.1109/tfuzz.2009.2016552
Abstract: This paper investigates the quadratic
stabilizability of Takagi-Sugeno (T-S) fuzzy systems
by means of parallel distributed state feedback
compensators. Using Finsler's lemma, a new design
condition assuring the existence of such a controller is
formulated as a parameter-dependent linear matrix
inequality (LMI) with extra matrix variables and
parameters in the unit simplex. Algebraic properties of
the system parameters and recent results of positive
polynomials are used to construct LMI relaxations
that, differently from most relaxations in the literature,
provide certificates of convergence to solve the control
design problem. Due to the degrees of freedom
obtained with the extra variables, the conditions
presented in this paper are an improvement over
earlier results based only on Polya's theorem and can
Keywords: Multi-objective optimization - Artificial immune
system - Bayesian network-Building blocks-Combinatorial
optimization
Multi-Objective Biclustering: When Non-dominated
Solutions are not Enough
Guilherme Palermo Coelho, Fabrício Olivetti de França, Fernando
José Von Zuben
Journal of Mathematical Modelling and Algorithms - ISSN: 15701166 (Print) 1572-9214 (Onl
29
v:8 n:2 Jun-2009 pp:175-202 doi: 10.1007/s10852-009-9102-8
The biclustering technique was developed to
avoid some of the drawbacks presented by standard
clustering techniques, such as their impossibility of
finding correlating data under a subset of features,
and, consequently, to allow the extraction of more
accurate information from datasets. Given that
biclustering requires the optimization of at least two
conflicting objectives (residue and volume) and that
multiple independent solutions are desirable as the
outcome, a few multi-objective evolutionary
algorithms for biclustering were proposed in the
literature. However, these algorithms only focus their
search in the generation of a global set of nondominated biclusters, which may be insufficient for
most of the problems as the coverage of the dataset
can be compromised. In order to overcome such
problem, a multi-objective artificial immune system
capable of performing a multipopulation search,
named MOM-aiNet, was proposed. In this work, the
MOM-aiNet algorithm will be described in detail, and
an extensive set of experimental comparisons will be
performed, with the obtained results of MOM-aiNet
being confronted with those produced by the popular
CC algorithm, by another immune-inspired approach
for biclustering (BIC-aiNet), and by the multiobjective approach for biclustering proposed by Mitra
& Banka.
Abstract:
Keywords: Biclustering, Multi-objective optimization,
Multipopulation search, Artificial immune systems
Stability analysis and gain-scheduled state
feedback control for continuous-time systems with
bounded parameter variations
Vinícius Foletto Montagner, Ricardo Coração de Leão F. de
Oliveira, Pedro Luis Dias Peres, Pierre-Alexandre Bliman
International Journal of Control (Print) - ISSN: 1366-5820
(electronic) 0020-7179
v:82 n:6 Jun-2009 pp:1045-1059 doi: 10.1080/00207170802403750
Abstract: The problems of robust stability analysis and
state feedback control based on gain-scheduling for
continuous-time systems with time-varying parameters
that have bounded rates of variation and lie inside a
polytope are addressed in this article. With respect to
previous results in the literature, two main
contributions of the article are: (i) the robust stability
analysis conditions are less conservative and demand
less computational effort than the existing ones; (ii)
the conditions can be extended to cope with the
problem of control design for this class of system.
Parameter-dependent linear matrix inequality (LMI)
conditions are given for the existence of a parameterdependent Lyapunov function quadratic in the state
and homogeneous polynomially of arbitrary degree in
the parameter assuring robust stability. Two convex
procedures based on LMIs exhibiting distinct
complexities are proposed to solve the problem of
robust stability. An extension to deal with the
computation of a stabilising parameter-dependent state
30
feedback gain for this class of time-varying systems is
also provided, as a sequence of LMIs of increasing
precision. Examples illustrate the results, including
comparisons with other techniques from the literature.
Keywords: LPV systems; robust stability; gain-scheduling;
LMIs; continuous-time systems
Electronic, Opto-electronic, Micro-electronic
Magnetically Coupled Current Sensors Using
CMOS Split-Drain Transistors
Fernando Cardoso Castaldo, Vilson Rodrigo Mognon, Carlos
Alberto dos Reis Filho
IEEE Transactions on Power Electronics - ISSN: 0885-8993
v:24 n:7 Jul-2009 pp:1733-1736 doi: 10.1109/TPEL.2009.2014133
Abstract: Integrated current sensing circuits intended
for Smart-Power and embedded applications featuring
galvanic isolation are implemented. They are based on
magnetic detection using the CMOS compatible splitdrain transistor (MAGFET) that provides a very linear
output current versus magnetic field. Two approaches
are used to generate the magnetic field. The coil
approach and the strip approach. In the first one the
current to be sensed flows through an integrated coil
placed atop the split-drain transistor and produces a
relatively strong magnetic coupling enough to cause a
detectable current. The second approach features an
array of 126-paralleled split-drain transistors along a
metal strip intended to carry higher current levels.
Both techniques were realized as integrated current
sensors built in 0.35mum CMOS technology. The
calculated and measured sensitivities were around 1
and 0.75muA/A for the coil and strip approaches
respectively. For a typical single split-drain bias
current of 50ìA, the minimum detectable current
within 1Hz are 2.8 and 42muA/radicHz for the coil
and strip approaches respectively. The strip can carry
currents up to 500mA, whereas the flowing current in
the coil is limited to 20mA. Thus, the choice is based
on the resolution and sensing current level of the
application.
Keywords: Current measurement, noise correlation, split
drain
Refractive index effect in the lattice geometry of
photonic crystals generated by multi-exposure
interference patterns
E.J. Carvalho, Edmundo da Silva Braga, Lucila Helena Deliesposte
Cescato
Journal of Optics. A, Pure and Applied Optics - ISSN: 2040-8978
(Print) 2040-8986 (On
v:11 n:7 Jul-2009 pp:75103-75108 doi: 10.1088/14644258/11/7/075103
Abstract: Different types of 2D and 3D photonic
crystal lattices may be recorded using the multiexposure of dual beam interference patterns by
varying the number of exposures and the rotation
angles of the sample between the exposures. The
lattice geometry of the photonic crystal is a crucial
parameter for the appearance of photonic band gaps.
In this paper we show both theoretically and
experimentally that for certain types of structure the
Sinopse da FEEC
lattice geometry of the superimposed interference
pattern, inside the photosensitive material, changes
drastically due to light refraction.
Keywords: Holography, structured photonic materials,
photonic crystals
Rise Time and Gain Fluctuations of an Electro
Optical Amplified Switch Based on Multi Pulse
Injection in Semiconductor Optical Amplifiers
Napoleão dos Santos Ribeiro, Adriano Luís Toazza, Cristiano de
Mello Gallep, Evandro Conforti
IEEE Photonics Technology Letters - ISSN: 1041-1135
v:21 n:12 Jun-2009 pp:769-771 doi: 10.1109/LPT.2009.2017731
Keywords: Devices, MOSFET, Polysilicon.
Biomedical Engineering
Sistema para Geração, Aquisição e Processamento
de Sinais de Ultra-Som
Amauri Assef, Joaquim Miguel Maia, Pedro M. Gewehr, Humberto
Remigio Gamba, Eduardo Tavares Costa, Vera Lucia da Silveira
Nantes Button
Revista SBA - Controle & Automação - ISSN: 0103-1759
v:20 n:2 Jun-2009 pp:145-155
Resumo: Este trabalho apresenta um sistema de
geração, aquisição e processamento de sinais de ultrasom para caracterização de materiais. O sistema
permite operação nos modos pulso-eco e transmissãorecepção, com taxa de amostragem configurável entre
5 MHz e 80 MHz, sincronismo interno, taxa de
repetição dos pulsos de excitação dos transdutores
entre 111 Hz e 333 Hz, largura do pulso de
aproximadamente 100 ns e amplitude de 200 V. Os
circuitos de recepção operam na faixa entre 20 kHz e
30 MHz, com controle de ganho entre -40 dB e +40
dB. Para avaliar o desempenho do sistema, foram
realizadas medidas de velocidade de progação e
atenuação em banda larga de ondas ultra-sônicas em
acrílico e água. Os resultados obtidos apresentaram
erros inferiores a 1 %, evidenciando que o sistema
apresenta boa repetibilidade e pode ser utilizado em
testes não invasivos e não destrutivos para
caracterização de diferentes materiais.
Abstract: Subnanosecond electrooptical switching
times with 26-dB extinction ratio were obtained by
using semiconductor optical amplifiers driven by a
multipulse injection current. The multipulse switching
current was generated by superimposing fast
electronic pulse signals in a microwave resistive
combiner. Although very fast switching is achievable,
nonlinear behavior and circuits parasitic induce gain
fluctuations and overshooting during the off–on
process. Theoretical and experimental results show
that the reduction of parasitics is an important
parameter for improving the switching performance.
The multipulse injection technique can improve the
switching speed for a chosen degree of overshoot.
Keywords: Electrooptical switches, optical switches,
semiconductor optical amplifiers (SOAs)
Palavras-chave: Ultra-som, velocidade de propagação do
som, atenuação em banda larga, caracterização de
materiais
The influence of Poly-Si/SiGe gate in threshold,
sub-threshold parameters and low frequency noise
in p-MOSFETs
Hugo Ricardo Jimenez Grados, Leandro Tiago Manêra, M. F.
Rautemberg, José Alexandre Diniz, Ioshiaki Doi, Peter Jurgen
Tatsch, Hugo Enrique Hernandez Figueroa, Jacobus Willibrordus
Swart
ECS Transactions - ISSN: 1938-5862 (print) 1938-6737 (o
Natal,RN - Brasil v:23 n:1 Aug-2009 pp:371-380 doi:
10.1149/1.3183741
DC performance and Low Frequency Noise
in p-MOS transistor with poly-Si/SiGe Gate fabricated
with the CMOS process entirely developed in the
Center for Semiconductor Components at UNICAMP
is presented. After deposition, films of poly-Si and
poly SiGe were implanted by phosphorus ions. The
transistor has a channel region with silicon oxide
thickness of 30 nm and a poly-Si/SiGe gate region
with self-aligned thick S/D region. The parameters on
threshold, sub-threshold and low frequency noise (1/f)
of poly-Si/SiGe p-MOS transistor are reported. The
turn-on in the I-V characteristics increases and at a
drain-to-source bias VDS of -0.1V p-MOSFETs with
Lpoly=1.57µm gate length had peak transconductance
(Gm) increased as well, compared with conventional
p-MOS with poly-Si gate. The DC and 1/f
characteristics of the p-MOS transistors are studied
using several devices sizes. Devices show low 1/f and
high values for Gm parameters and make them
promising devices for RF and microwave circuit
applications.
Abstract:
The role of extracellular potassium dynamics in the
different stages of ictal bursting and spreading
depression: A computational study
Gerson Florence, Markus A. Dahlem, Antônio Carlos G. Almeida,
José Wilson Magalhães Bassani, Juergen Kurths
Journal of Theoretical Biology - ISSN: 0022-5193
v:258 n:2 May-2009 pp:219-228 doi: 10.1016/j.jtbi.2009.01.032
Boletim Acadêmico da FEEC-Unicamp - Vol. 2 número 2
Experimental evidences point out the
participation of nonsynaptic mechanisms (e.g.,
fluctuations in extracellular ions) in epileptiform
bursting and spreading depression (SD). During these
abnormal oscillatory patterns, it is observed an
increase of extracellular potassium concentration [K+]o
and a decrease of extracellular calcium concentration
[Ca2+]o which raises the neuronal excitability.
However, whether the high [K+]o triggers and
propagates these abnormal neuronal activities or plays
a secondary role into this process is unclear. To better
understand the influence of extracellular potassium
dynamics in these oscillatory patterns, the
experimental conditions of high [K+]o and zero [Ca2+]o
were replicated in an extended Golomb model where
we added important regulatory mechanisms of ion
concentration as Na+ - K+ pump, ion diffusion and
glial buffering. Within these conditions, simulations of
the cell model exhibit seizure-like discharges (ictal
bursting). The SD was elicited by the interruption of
Abstract:
31
the Na+- K+ pump activity, mimicking the effect of
cellular hypoxia (an experimental protocol to elicit
SD, the hypoxia-induced SD). We used the bifurcation
theory and the fast-slow method to analyze the
interference of K+ dynamics in the cellular excitability.
This analysis indicates that the system loses its
stability at a high [K+]o, transiting to an elevated state
of neuronal excitability. Effects of high [K+]o are
observed in different stages of ictal bursting and SD.
In the initial stage, the increase of [K+]o creates
favorable conditions to trigger both oscillatory
patterns. During the neuronal activity, a continuous
growth of [K+]o by outward K+ flow depresses K+
currents in a positive feedback way. At the last stage,
due to the depression of K+ currents, the Na+- K+
pump is the main mechanism in the end of neuronal
activity. Thus, this work suggests that [K+]o dynamics
may play a fundamental role in these abnormal
oscillatory patterns.
Keywords: Extracellular potassium concentration ;
Excitability ; Bifurcation ; Ictal bursting ; Spreading
depression
Computer Engineering
Artificial Immune Systems: structure, function,
diversity and an application to biclustering
Leandro Nunes de Castro Silva, Jon Timmis, Helder Knidel,
Fernando José Von Zuben
Natural Computing - ISSN: 1567-7818 (Print) 1572-9796 (Onl
v:1 n:0 Jul-2009 pp:1-3 doi: 10.1007/s11047-009-9145-9
Abstract: The area of Artificial Immune Systems (AIS)
is one of the most recent natural computing
approaches and arose from the inter-disciplinary
workings of immunologists, computer scientists, and
engineers to develop solutions to such problems as
distributed control and computer security. The field
has developed significantly over the recent years, with
the development of solutions to a wide variety of
problems ranging from optimization, fault tolerance,
data mining, bioinformatics, and robotic systems. This
paper describes and motivates the content of the
Special Issue of this volume of Natural Computing
Journal, which brings together extended papers from
the 6th International Conference on Artificial Immune
Systems, hosted in Santos, Brazil in August 2007.
Keywords: Artificial immune systems; structure and
function; biclustering.
Cellular automata with fuzzy parameters in
microscopic study of positive HIV individuals
R. Motta Jafelice, B.F.Z. Bechara, L.C. Barros, R.C. Bassanezi,
Fernando Antonio Campos Gomidee
Mathematical and Computer Modelling - ISSN: 0895-7177
v:50 n:1 Jul-2009 pp:32-44 doi: 10.1016/j.mcm.2009.01.008
Abstract: The aim of this paper is to introduce a model
to simulate the evolution of HIV in the bloodstream of
positive individuals subject to medical treatment and
monitoring of the medication potency and treatment
adhesion. For this purpose, a cellular automata
approach coupled with fuzzy set theory is developed
32
to study the HIV evolution. The study is conducted
using two cellular automata models in two
corresponding steps. The first step concerns HIV
dynamics in individuals with no antiretroviral therapy.
In this case, the trajectory developed by the cellular
automaton model depicts all phases shown in the
known history of HIV dynamics. The main purpose of
the first step is to serve as a model validation step. The
second step extends the model developed in the first
step to consider HIV dynamics in individuals under
antiretroviral therapy. The effects of antiretroviral
therapy in the cellular automaton model are modeled
using a fuzzy rule-based system with two inputs, the
medication potency and treatment adhesion rate of the
individuals to the therapy. The fuzzy rule-based
system is used to compute the number of HIV infected
CD4+ cells and the viral replication. The results
developed by the cellular automaton model with
antiretroviral therapy are close to the ones reported in
the literature and agree with the behavior expected by
experts [J. Guedj, R. Thiébaut, D. Commenges,
Practical identifiability of HIV dynamics models,
Bulletin of Mathematical Biology 69 (8) (2007) 2493–
2513], [R.A. Filter, X. Xia, C.M. Gray, Dynamic
HIV/AIDS parameter estimation with application to a
vaccine readiness study in southern Africa, IEEE
Transactions on Biomedical Engineering 52 (5) (2005)
784–791] and [D.A. Ouattara, M.J. Mhawej, C.H.
Moog, Clinical tests of therapeutical failures based on
mathematical modeling of the HIV infection, Systems
Biology (2008) 230–241 (special issue)]
Keywords: Cellular automata; Fuzzy sets; HIV dynamics;
Antiretroviral therapy
Prediction of binding hot spot residues by using
structural and evolutionary parameters
Roberto Hiroshi Higa, Clésio Luis Tozzi
Genetics and Molecular Biology - ISSN: 1415-4757
v:32 n:3 Jul-2009 pp:626-633 doi: 10.1590/S141547572009000300029
Abstract: In this work, we present a method for
predicting hot spot residues by using a set of structural
and evolutionary parameters. Unlike previous studies,
we use a set of parameters which do not depend on the
structure of the protein in complex, so that the
predictor can also be used when the interface region is
unknown. Despite the fact that no information
concerning proteins in complex is used for prediction,
the application of the method to a compiled dataset
described in the literature achieved a performance of
60.4%, as measured by F-Measure, corresponding to a
recall of 78.1% and a precision of 49.5%. This result is
higher than those reported by previous studies using
the same data set.
Keywords: hot spots prediction, protein structure, hot
spots.
RECONSTRUÇÃO TRIDIMENSIONAL POR VISÃO
ESTÉREO E DETECÇÃO DE OCLUSÕES
Fernando Marques de Almeida Nogueira, Clésio Luis Tozzi
Sinopse da FEEC
RBC - Revista Brasileira de Cartografia - ISSN: 0560-4613
v:61 n:2 Ago-2009 pp:91-103
Resumo: Este trabalho apresenta uma nova abordagem
iterativa e hierárquica para a obtenção de mapas
densos de disparidade (paralaxe), a partir de um par de
imagens estereoscópicas normalizadas, na qual
oclusões são explicitamente identificadas. Esta
abordagem se fundamenta num processo de busca
hierárquica onde são determinados pares homólogos
prioritários sobre os quais é aplicada a Injunção de
Ordem. Pares homólogos prioritários consistem nos
pontos que apresentam a propriedade de
Correspondência Bidirecional para o maior número de
janelas de busca organizadas em ordem crescente de
tamanho. A aplicação da Injunção de Ordem aos pares
homólogos prioritários elimina, já nas primeiras
iterações, uma grande quantidade de correspondências
ambíguas aumentando o índice de acertos e reduzindo
o tempo de execução. A abordagem proposta destacase pela utilização de apenas dois parâmetros que
devem ser fornecidos a priori de maneira empírica:
tamanho inicial da janela e número de níveis
hierárquicos. A eficiência do algoritmo proposto foi
avaliada a partir de imagens reais e simuladas e os
resultados comparados com outras abordagens
descritas na literatura.
Correspondência
Disparidade, Paralaxe.
Palavras-chave:
Estéreo,
Oclusão,
transposed three-phase transmission line decomposed
in its exact modes by using two transformation
matrices. The first matrix is Clarke’s matrix that is
real, frequency independent, easily represented in
computational transient programs (EMTP) and
separates the line into quasi-modes a, b and zero. After
that, Quasi-modes a and zero are decomposed into
their exact modes by using a modal transformation
matrix whose elements can be synthesized in time
domain through standard curve-fitting techniques. The
main advantage of this alternative representation is to
reduce the processing time because a frequency
dependent modal transformation matrix of a threephase line has nine elements to be represented in time
domain while a modal transformation matrix of a twophase line has only four elements. This paper shows
modal decomposition process and eigenvectors of a
nontransposed three-phase line with a vertical
symmetry plane whose nominal voltage is 440 kV and
line length is 500 km.
Keywords: electromagnetic transients analysis, frequency
domain analysis, time domain analysism transmission line
matrix methods.
An Investigation on the Selection of Filter
Topologies for Passive Filter Applications
Alexandre Nassif, Wiliun Xu, Walmir de Freitas Filho
IEEE Transactions on Power Delivery - ISSN: 0885-8977
v:24 n:3 Jul-2009 pp:1710-1718 doi:
10.1109/TPWRD.2009.2016824
Robustness of multimodal biometric fusion
methods against spoof attacks
Passive filters have been a very effective
solution for power system harmonic mitigation. These
filters have several topologies that give different
frequency response characteristics. The current
industry practice is to combine filters of different
topologies to achieve a certain harmonic filtering goal.
However, there is a lack of information on how to
select different filter topologies. This decision is based
on the experience of present filter designers. The goal
of this paper is to investigate the filter topology
selection issue. It presents our research results on the
effectiveness and costs of various filter topologies for
harmonic mitigation. The research results show that
the association of three single-tuned filters is a very
appropriate solution for most typical harmonic
problems.
Abstract:
Ricardo Nagel Rodrigues, Lee Luan Ling, Venu Govindaraju
Journal of Visual Languages and Computing - ISSN: 1045-926X
v:20 n:3 Jun-2009 pp:169-179 doi: 10.1016/j.jvlc.2009.01.010
In this paper, we address the security of
multimodal biometric systems when one of the modes
is successfully spoofed. We propose two novel fusion
schemes that can increase the security of multimodal
biometric systems. The first is an extension of the
likelihood ratio based fusion scheme and the other
uses fuzzy logic. Besides the matching score and
sample quality score, our proposed fusion schemes
also take into account the intrinsic security of each
biometric system being fused. Experimental results
have shown that the proposed methods are more
robust against spoof attacks when compared with
traditional fusion methods.
Abstract:
Keywords: Multimodal biometrics; Secure biometrics;
Face recognition; Fingerprint
Electrical Energy
Alternative proposal for Modal Representation of a
Non-transposed Three-Phase Transmission Line
with a Vertical Symmetry Plane
Sergio Kurokawa, Rodrigo Serra Daltin, Afonso José do Prado,
José Pissolato Filho, Luiz Fernando Bovolato
Revista IEEE América Latina - ISSN: 1548-0992
v:7 n:2 Jun-2009
Keywords: Passive filters, power system harmonics.
Analysis of the E-J Curve of HTS Tapes Under DC
and AC Magnetic Fields at 77 K
Carlos Yujiro Shigue, de la Cruz, F. P, Jérika Suely Lamas, Carlos
Alberto Baldan, Ernesto Ruppert Filho
IEEE Transactions on Applied Superconductivity - ISSN: 10518223
v:19 n:3 Jul-2009 pp:3332 - 3335 doi:
10.1109/TASC.2009.2018309
Abstract: The objective of this paper is to show an
alternative representation in time domain of a non-
Abstract:
The evaluation of the electrical
characteristics of technical HTS tapes are of the key
importance in determining the design and operational
features of superconducting power apparatuses as well
as to understand the external factors which affect the
33
superconducting performance. In this work we report
the systematic measurements of the electric field
versus current density, E - J relation of short samples
for three commercial HTS tapes (BSCCO-2223 tapes,
with and without steel reinforcement, and YBCOcoated conductor) at 77 K. In order to get sensitive and
noiseless voltage signals the measurements were
carried out with DC transport current and subjecting
the broad surface tape to DC (0-300 mT) and AC (062 mT, 60 Hz) magnetic fields. The voltage is
measured by a sensitive nanovoltmeter and the applied
magnetic field is monitored by a Hall sensor placed on
the tape broad surface. The comparison between the E
- J results obtained from the three tapes was done by
fitting a power-law equation for currents in the
vicinity of the critical current. For the current regime
below the critical one a linear correlation of the
electric field E against the current density is observed.
The BSCCO samples presented the same behavior,
i.e., a decreasing of n-index with the increasing DC
and AC magnetic field strength. Under AC field the
decreasing slope of n-index is steeper as compared to
DC field. The n-index curve for the YBCO tape
showed similar behavior for AC field, however under
DC field in the 0-390 mT range exhibited a slight
decreasing of the n-index.
Keywords: AC losses, HTS tapes, critical current, power-
law relation
Comprehensive Approach to Modeling and
Simulation of Photovoltaic Arrays
Marcelo Gradella Villalva, Jonas Rafael Gazoli, Ernesto Ruppert
Filho
IEEE Transactions on Power Electronics - ISSN: 0885-8993
v:24 n:5 May-2009 pp:1198-1208 doi:
10.1109/TPEL.2009.2013862
Abstract: This paper proposes a method of modeling
and simulation of photovoltaic arrays. The main
objective is to find the parameters of the nonlinear I–V
equation by adjusting the curve at three points: open
circuit, maximum power, and short circuit. Given
these three points, which are provided by all
commercial array datasheets, the method finds the best
I–V equation for the single-diode photovoltaic (PV)
model including the effect of the series and parallel
resistances, and warranties that the maximum power
of the model matches with the maximum power of the
real array. With the parameters of the adjusted I–V
equation, one can build a PV circuit model with any
circuit simulator by using basic math blocks. The
modelingmethod and the proposed circuit model are
useful for power electronics designers who need a
simple,
fast,
accurate,
and
easy-to-use
modelingmethod for using in simulations of PV
systems. In the first pages, the reader will find a
tutorial on PV devices and will understand the
parameters that compose the single-diode PV model.
The modeling method is then introduced and presented
34
in details. The model is validated with experimental
data of commercial PV arrays.
Keywords: Array, circuit, equivalent, model, modeling,
photovoltaic (PV), simulation.
Evaluation of Electrical Properties of Lap Joints for
BSCCO and YBCO Tapes
Carlos Yujiro Shigue, de la Cruz, F. P, Jérika Suely Lamas, Carlos
Alberto Baldan, Ernesto Ruppert Filho
v:19 n:3 Jul-2009 pp:2831 - 2834 doi:
10.1109/TASC.2009.2017701
Abstract: The joint process between tapes of coated
conductors is a critical issue for the most of the
applications of high temperature superconductors
(HTS). Using different fabrication techniques joints of
YBCO coated superconductors were prepared and
characterized through electrical measurements. For
soldering material low melting point eutectic alloys,
such as In-Sn (m.p. 116degC) and Sn-Pb (m.p.
189degC) were selected to prepare lap joints with
effective length between 1 to 20 cm. The splice
resistance and the critical current of the joints were
evaluated by I-V curve measurements with the
maximum current strength above the critical current,
in order to evaluate the degree of degradation for each
joint method. Pressed lap joints prepared with tapes
without external reinforcement presented low
resistance lap joint nevertheless some critical current
degradation occurs when strong pressing is applied.
When mechanical pressure is applied during the
soldering process we can reduce the thickness of the
solder alloy and a residual resistance arises from
contributions of high resistivity matrix and external
reinforcement. The lap joints for reinforced tape were
prepared using two methods: the first, using ldquoassuppliedrdquo tape and the other after reinforcementremoval; in the latter case, the tapes were resoldered
using Sn-Pb alloy. The results using several joint
geometries, distinct surface preparation processes and
different soldering materials are presented and
analysed. The solder alloy with lower melting point
and the longer joint length presented the smallest joint
resistance.
Keywords: Critical current, HTS tapes, joint length, low
resistance lap joint
Fault Current Limiter Using YBCO Coated
Conductor-The Limiting Factor and Its Recovery
Time
C. A. Baldan, J. S. Lamas, C. Y. Shigue, Ernesto Ruppert Filho
v:19 n:3 Jun-2009 pp:1810-1813 doi: 10.1109/TASC.2009.2019043
A fault current limiter (FCL) based on an
arrangement of parallel connected high temperature
superconducting tapes constituting a limiter element
was designed and tested in 220 V line for a fault
current peak between 1 kA to 2 kA. The limiter
employed second generation (2G) HTS tapes of
Abstract:
Sinopse da FEEC
YBCO coated conductor reinforced with stainless
steel. Four tapes were electrically connected in parallel
with 0.4 m effective length per element wherein 16
elements connected in series constitutes a single-phase
unit. The FCL performance was evaluated through
over-current and current fault tests. Its recovery
characteristics were used to design the shunt
protection. The designed limiting ratio is 4 for 16
elements and the experimental result for one element
showed a 20% limiting ratio. For the fault current test
one element can withstand five cycles of fault without
degradation. It was observed recovery times below 0.5
s under nominal load using a shunt resistance of 173
mOmega.
account the frequency dependence. To confirm the
validation of the state matrices obtained, the lumped
parameters representation of frequency-dependent
lines was used to represent a single-phase line and a
three-phase line. The simulations were carried out
using state space techniques and an electromagnetic
transient program (EMTP) (in this case, the cascade
was inserted in the EMTP). It is observed that the
simulation results obtained with state space
representation are in agreement with those results
obtained with EMTP.
Keywords: Current limiting ratio, YBCO coated conductor,
Interior Point for Long-Term Generation Scheduling
of Large-Scale Hydrothermal Systems
YBCO recovery characteristics, superconducting fault
current limiter
H∞ Filtering of Discrete-time Markov Jump Linear
Systems Through Linear Matrix Inequalities
Alim Pedro de Castro Gonçalves, André R. Fioravanti, José
Claudio Geromel
IEEE Transactions on Automatic Control - ISSN: 0018-9286
v:54 n:6 Jun-2009 pp:1347 - 1351 doi: 10.1109/TAC.2009.2015553
Keywords:
Electromagnetic transients, Frequency
dependence, Time domain, Transmission line, Transmission
line parameters, State space methods
Anibal Tavares Azevedo, Aurelio Ribeiro Leite Oliveira, Secundino
Soares Filho
Annals of Operation Research - ISSN: 0254-5330 (Print)
v:169 n:1 Jul-2009 pp:55-80 doi: 10.1007/s10479-008-0389-z
This paper presents an interior point method
for the long-term generation scheduling of large-scale
hydrothermal systems. The problem is formulated as a
nonlinear programming one due to the nonlinear
representation of hydropower production and thermal
fuel cost functions. Sparsity exploitation techniques
and an heuristic procedure for computing the interior
point method search directions have been developed.
Numerical tests in case studies with systems of
different dimensions and inflow scenarios have been
carried out in order to evaluate the proposed method.
Three systems were tested, with the largest being the
Brazilian hydropower system with 74 hydro plants
distributed in several cascades. Results show that the
proposed method is an efficient and robust tool for
solving the long-term generation scheduling problem.
Abstract:
This technical note addresses the discretetime Markov jump linear systems H∞ filtering design
problem. First, under the assumption that the Markov
parameter is measurable, the main contribution is the
linear matrix inequality (LMI) characterization of all
linear filters such that the estimation error remains
bounded by a given H∞ norm level, yielding the
complete solution of the mode-dependent filtering
design problem. Based on this result, a robust filter
design able to deal with polytopic uncertainty is
considered. Second, from the same LMI
characterization, a design procedure for modeindependent filtering is proposed. Some examples are
solved for illustration and comparisons.
Abstract:
Keywords: Hydrothermal generation scheduling - Longterm operational planning - Nonlinear optimization Interior point method
Keywords: Discrete-time systems, Markov jump linear
systems, linear matrix inequalities (LMIs), robust filtering
Inclusion of the frequency effect in the lumped
parameters transmission line model: State space
formulation
Sergio Kurokawa, Fabio N. R. Yamanaka, Afonso J. Prado, José
Pissolato Filho
Electric Power Systems Research (Print) - ISSN: 0378-7796
v:79 n:7 Jul-2009 pp:1155-1163 doi: 10.1016/j.epsr.2009.02.007
Investigation of Positive Feedback Anti-Islanding
Control for Multiple Inverter-Based Distributed
Generators
Xiaoyu Wang, Walmir Freitas, Venkata Dinavahi, Wilsun Xu
IEEE Transactions on Power Systems - ISSN: 0885-8950
v:24 n:2 May-2009 pp:785-795 doi: 10.1109/TPWRS.2008.2007002
The objective of this paper is to include the
frequency dependence of the longitudinal parameters
in the lumped parameters line model. The distributed
nature of the transmission line was approximated by a
cascade of ð circuits and the frequency effect was
approximated by a rational function which was
synthesized by an equivalent circuit. Then, the
equivalent circuit was inserted in each ð circuit of the
cascade. After that, the currents and voltages along the
line were described in the form of state equations. This
way, it was possible to obtain a formation rule of the
state matrices lumped parameters model taking into
Abstract:
Abstract: The positive feedback-based anti-islanding
scheme has become a common anti-islanding
protection technique for inverter-based distributed
generators (DGs). This paper investigates the scheme's
impact on the small-signal stability of multiple
inverter-based DGs installed in power distribution
systems during grid-connected operation. The
interactions among multiple-DGs due to the antiislanding scheme are also addressed. An index is
proposed to quantify the destabilizing effect of the
aggregated positive feedback activities of multiple
DGs. This paper further introduces a DG power
transfer limit versus islanding detection time curve to
35
reveal the conflicting requirements of anti-islanding
protection speed and the maximum power transfer of
multi-DG systems.
Keywords: Distributed generator, inverter, islanding,
positive feedback, small-signal model.
Life cycle cost analysis of energy efficiency design
options for refrigerators in Brazil.
Edson Adriano Vendrusculo, Guilherme de Castilho Queiroz,
Gilberto De Martino Jannuzzi, Herculano Xavier da Silva Júnior,
José Antenor Pomilio
Energy Efficiency - ISSN: 1570-646X (Print) 1570-6478 (Onl
v:2 n:3 Aug-2009 pp:271-286 doi: 10.1007/s12053-008-9034-6
The purpose of this paper was to present the
results of a life cycle cost analysis concerning the
purchase and operation of a more efficient popular
refrigerator model compared with a baseline design in
Brazil. The summarized results may be useful for
organizations working to promote sustainable energy
development. This paper specifically focuses on
refrigerators, since their energy consumption is
predicted to constitute over 30% of the total average
domestic electricity bill in Brazilian households. If all
new Brazilian refrigerators had an energy efficiency at
the level consistent with the least life cycle cost of
ownership, it would result in an annual savings of 2.8
billion dollars (US$) in electricity bills, 45 TWh of
electricity demand, and 18 Mt of CO2 emissions, with
a respective payback period of 7 years which is less
than half the average estimated lifetime of a
refrigerator. The analysis was conducted following the
guidelines of similar analyses available from the US
Department of Energy and the Collaborative Labeling
and Appliance Standards Program.
Abstract:
Keywords: Electrical consumption - Energy efficiency Household refrigerator - Life cycle cost analysis - Minimum
energy performance standards - Payback period
Redução das Correntes de Arco Secundário em
Sistemas de Transmissão Típicos
Milton Elvis Zevallos Alcahuaman, Maria Cristina Dias Tavares
Revista SBA - Controle & Automação - ISSN: 0103-1759
v:20 n:3 Jul-2009 pp:373-382 doi: 10.1590/S010317592009000300008
Resumo: Neste trabalho otimizamos o valor de reator
de neutro para conseguir minimizar a corrente de arco
secundário em sistemas de transmissão com
compensação reativa em derivação. Através de uma
análise de sensibilidade conseguimos identificar
valores de reator de neutro para os quais se consegue
uma alta probabilidade de auto-extinção da corrente de
arco secundário para diferentes sistemas de
transmissão visando assegurar uma manobra
abertura/religamento monopolar com sucesso. O
método para identificar o reator de neutro ótimo e os
valores das correntes de arco secundário para linhas
típicas do sistema brasileiro são apresentados.
Smart demand for improving short-term voltage
control on distribution networks
Valle Garcia, Luiz Carlos Pereira da Silva, Z. XU, J. Ostergaard
IET Generation, Transmission & Distribution - ISSN: 1751-8687
v:3 n:8 Aug-2009 pp:724–732 doi: 10.1049/iet-gtd.2008.0621
Smart grids must involve active roles from
end users in order to be truly smart. The energy
consumption has to be done in a flexible and
intelligent manner, in accordance with the current
conditions of the power system. Moreover, with the
advent of dispersed and renewable generation,
increasing customer integration to aid power system
performance is almost inevitable. This study
introduces a new type of smart demand side
technology, denoted demand as voltage controlled
reserve (DVR), to improve short-term voltage control,
where customers are expected to play a more dynamic
role to improve voltage control. The technology can be
provided by thermostatically controlled loads as well
as other types of load. This technology is proven to be
effective in case of distribution systems with a large
composition of induction motors, where the voltage
presents a slow recovery characteristic due to
deceleration of the motors during faults. This study
presents detailed models, discussion and simulation
tests to demonstrate the technical viability and
effectiveness of the DVR technology for short-term
voltage control.
Abstract:
Keywords: ordinal optimisation approach, distributed
generation capacity maximisation, linear programming
model, crude model evaluation, nonlinear programming
optimal power flow, alignment probability, distribution
network operator
The complex controller applied to the induction
motor control
Alfeu Joãozinho Sguarezi Filho, Ernesto Ruppert Filho
Eletrônica de Potência - ISSN: 1414-8862
v:14 n:3 Ago-2009 pp:201-210
This paper presents a design and tuning
method of the complex gain controller, based on the
three-phase
induction
motormathematicalmodel
complex transfer function to be used in induction
motor control when the machine operates at low speed
which is a problem so far. The complex gain controller
was applied in the direct rotor field orientation
controlmethod and also on the direct torque control
method. It was designed and tuned using the
frequency-response function of the closed loop
system. The complex gain controller presents low
complexity
in
the
inductionmotor
control
implementation. Experimental results were carried out
for the controller validation.
Resumo:
Palavras-chave: Induction Motor Control, Complex gain
controller, Complex Transfer Function, Field orientation
Direct torque control.
Palavras-chave: Arco Secundário, Compensação Reativa,
Manobra Monofásica, Quadripolos e Reator de Neutro.
36
Sinopse da FEEC
capturing multifractal network traffic characteristics.
In addition, the authors^ derive an analytical
expression for the effective bandwidth estimation of^
AWMM traffic flows, capable of being used to meet
desired^ byte loss probabilities. Finally, they present
an online effective bandwidth^ estimation algorithm
that is incorporated into an adaptive bandwidth
provisioning^ scheme and comparatively evaluated
against some other bandwidth allocation methods.
Telecommunication and Telematic
A Fair Scheduling Discipline for Ethernet Passive
Optical Networks
Flávio de Melo Pereira, Nelson Luis Saldanha da Fonseca, Dalton
Soares Arantes
Computer Networks - ISSN: 1389-1286
v:53 n:11 Jul-2009 pp:1859-1878 doi:
doi:10.1016/j.comnet.2009.02.020
We propose a novel policy for scheduling
upstream flows in Ethernet passive optical networks.
This policy, called proportional sharing with load
reservation (PSLR), provides bandwidth guarantees on
a per-flow basis and redistributes the unused
bandwidth among active flows in proportion to their
priority level. We establish convergence conditions for
the PSLR policy and show that it provides a fair
service distribution among the flows. Moreover, we
establish bounds for the backlog and delay on a perflow basis, thus enabling a network to provide its users
with absolute performance guarantees.
Abstract:
Keywords: Tráfego Multifractal, Estimação de Banda
Efetiva, Modelagem de Tráfego.
Entropy coders and 3D-Hadamard coefficients
sequency scan order for a fast embedded color
video codec
Vanessa Testoni, Max Henrique Machado Costa
Computers and Electrical Engineering - ISSN: 0045-7906
Jun-2009 pp:1-15 doi: doi:10.1016/j.compeleceng.2008.11.018
Keywords: Ethernet passive optical networks; Scheduling
policy; Performance guarantees
Accurate Approximations to the Sum of
Generalized Random Variables and Applications in
the Performance Analysis of Diversity Systems
Daniel Benevides da Costa, Michel Daoud Yacoub
IEEE Transactions on Communications - ISSN: 00906778
v:57 n:5 May-2009 pp:1271-1274 doi:
10.1109/TCOMM.2009.05.070312
Accurate closed-form approximations to the
sum of independent identically distributed eta -mu and
kappa -mu random variables are provided. The
proposed approximations turn out to be simple,
precise, and useful for obtaining important
performance metrics of communications systems
where sums of variates arise. In particular, average bit
error rate and level crossing rate of multibranch equalgain combining receivers are attained to illustrate the
applicability of the approximations. Some sample
examples show that the intricate exact solution and the
simple approximate expressions yield results that are
almost indistinguishable from each other.
Abstract:
Diversity systems, generalized random
variables, η-μ sums, η-κ sums, performance analysis, sums
approximation methods
Keywords:
Adaptive wavelet-based multifractal model applied
to the effective bandwidth estimation of network
traffic flows
Flavio Henrique Teles Vieira, Lee Luan Ling
IET Communications - ISSN: 1751-8628
v:3 n:6 Jun-2009 pp:906-919 doi: 10.1049/iet-com.2008.0078
The^ authors investigate effective bandwidth
estimation and Quality of Service (QoS)^ aware
bandwidth provisioning for multifractal network
traffic flows. They develop^ a novel adaptive waveletbased multifractal model (AWMM) by using
properties^ of the wavelet coefficients of multifractal
cascade processes. The proposed^ AWMM has realtime updating capability and proves to be efficient^ in
Abstract:
Abstract: This work compares the performances of two
Golomb family entropy coders applied to a video
codec system named FHVC (fast hadamard video
codec). The entropy coders considered have different
operation modes and specific adaptation strategies.
The work also presents a new 3D-transform
coefficient scan order developed for the FHVC. This
scan process is based on the multiplication of the
three-dimensional sequency numbers of each
coefficient. The FHVC (which is also described in this
work) is a fast embedded color video codec developed
to be implemented in a video set-top box used in a
fiber optics network. The focus is on more reduced
execution times, and not on higher compression rates.
Low computational complexity and use of meager
computational resources are also required. All the
multiplications and divisions operations are performed
by binary shifts and the system is implemented
exclusively with 16-bit integer arithmetic. Even with
these constraints, good distortion versus bit-rate results
were achieved. The Hadamard transform is used in a
three-dimensional fashion, in order to reduce spatial
and temporal correlation and to avoid costly motion
estimation and compensation techniques. The
proposed scan procedure allows the transform
coefficient reading in an idealistic ‘‘decreasing in the
average” order. After the scan procedure, the encoding
of the bit sequence of the 3D-Hadamard coefficients is
carried out, bit-plane-by-bit-plane, with an adaptive
Golomb run-length entropy coder, which produces a
fully embedded output bitstream. Two entropy coders
were considered. The first one uses an empirical, but
fast and efficient, adaptation strategy that shows good
results on non-stationary data. The second one has an
adaptation strategy that is nearly optimum, in a
maximum-likelihood sense, for independent Bernoulli
identically distributed data.
Keywords: Embedded video coding, 3D-Hadamard
transform, Adaptive Golomb entropy coder, Fast video
codec, 3D-transform coefficient scan order, C# language
37
Estimating Frequency, Amplitude and Phase of
Two Sinusoids with Very Close Frequencies
Jayme Garcia Arnal Barbedo, Amauri Lopes
International Journal of Signal Processing - ISSN: 2070-397X
v:5 n:2 Jun-2009 pp:138-145
This paper presents an algorithm to estimate
the parameters of two closely spaced sinusoids,
providing a frequency resolution that is more than 800
times greater than that obtained by using the Discrete
Fourier Transform (DFT). The strategy uses a highly
optimized grid search approach to accurately estimate
frequency, amplitude and phase of both sinusoids,
keeping at the same time the computational effort at
reasonable levels. The proposed method has three
main characteristics: 1) a high frequency resolution; 2)
frequency, amplitude and phase are all estimated at
once using one single package; 3) it does not rely on
any statistical assumption or constraint. Potential
applications to this strategy include the difficult task
of resolving coincident partials of instruments in
musical signals.
Abstract:
Closely spaced sinusoids, high-resolution
parameter estimation, optimized grid search.
Keywords:
Feefforward Carrier Recovery for Polarization
Demultiplexed Signals with Unequal Signal to
Noise Ratios
Francisco Augusto da Costa Garcia, Darli Augusto de Arruda
Mello, Helio Waldman
Optics Express - ISSN: 1094-4087
v:17 n:10 May-2009 pp:7958-7969 doi: 10.1364/OE.17.007958
We investigate feedforward carrier recovery
(FFCR) in coherent polarization diversity receivers
where the signal to noise ratio (SNR) of polarization
demultiplexed signals can be unequal, such as in
polarization-dependent loss impaired systems. A jointpolarization FFCR mechanism for estimating the
carrier phase noise based on samples from both
polarizations is proposed and compared with three
other plausible alternatives. We evaluated each
architecture using Monte Carlo simulations and
observed that the joint-polarization FFCR yields a 1.1
dB SNR penalty for a given laser linewidth × baud
rate product, while the other three architectures offer
1.8 dB, 2.0 dB and 3.9 dB, for QPSK at BER = 10−3
and 3 dB SNR imbalance.
Abstract:
MRCS-Selecting Maximal Ratio Combined Signals:
A Practical Diversity Combining Scheme
Flávio Du Pin Calmon, Michel Daoud Yacoub
IEEE Transactions on Wireless Communications - ISSN: 15361276
v:8 n:7 Jul-2009 pp:3425-3429 doi: 10.1109/TWC.2009.080949
This paper presents and investigates a
general diversity combining scheme, here named
MRCS, in which maximal-ratio combined signals are
chosen on a selection combining basis. This
combining method has a simple implementation and a
tractable analytical formulation that can be directly
applied to situations in which site selection exists. A
general analysis of the probability distribution
Abstract:
38
(reliability), level crossing rate, and average fade
duration at the output of the combiner is provided,
along with examples for a Nakagami-m fading
environment. The main result of the present work,
however, is the derivation of an exact, easy-toevaluate closed-form expression for the mean signalto-noise ratio at the output of the combiner. Such an
expression is applicable for conditions in which the
product of the number of maximal-ratio combining
branches and the Nakagami-m parameter is an integer
and it generalizes a result presented elsewhere in the
literature. The formulations derived here find a direct
applicability in the dimensioning of practical wireless
networks.
Keywords: Diversity combining, maximal-ratio combining,
pure selection combining, Nakagami-m, soft handoff.
Articles in proceedings
Automation
A Bounded Cost Condition for the Existence of
Average Optimal Stationary Policies of Linear
Stochastic Systems
Alessandro do Nascimento Vargas, João Bosco Ribeiro do Val
In: European Control Conference (ECC)
Budapest, Hungria Aug-2009 pp:38-42
Abstract: This
note considers the long-run average cost
control problem of a discrete-time stochastic system.
The stochastic system is assumed to be linear with
respect to the state but the controls possess a general
structure, possibly nonlinear. The main contribution of
this paper is to show the existence of an optimal
stationary policy for the long-run average cost
problem provided that (i) there exists an $epsilon$optimal policy for the discounted problem and this
policy generates uniform bounded costs by stage, and
that (ii) a persistency of excitation condition is
satisfied. A numerical example illustrates the derived
result.
Keywords: Stochastic control, Optimal control, Markov
processes
A Complex Neighborhood Based Particle Swarm
Optimization
Alan Godoy Souza Mello, Fernando José Von Zuben
In: IEEE Congress on Evolutionary Computation - IEEE CEC
Norway, Noruega May-2009 pp:1-6
This paper proposes a new variant of the
PSO algorithm named Complex Neighborhood
Particle Swarm Optimizer (CNPSO) for solving global
optimization problems. In the CNPSO, the
neighborhood of the particles is organized through a
complex network which is modified during the search
process. This evolution of the topology seeks to
improve the influence of the most successful particles
and it is fine tuned for maintaining the scale-free
characteristics of the network while the optimization is
being performed. The use of a scale-free topology
instead of the usual regular or global neighborhoods is
Abstract:
Sinopse da FEEC
intended to bring to the search procedure a better
capability of exploring promising regions without a
premature convergence, which would result in the
procedure being easily trapped in a local optimum.
The performance of the CNPSO is compared with the
standard PSO on some wellknown and highdimensional benchmark functions, ranging from
multimodal to plateau-like problems. In all the cases
the CNPSO outperformed the standard PSO.
Keywords:
Particle
Swarm
Optimization,
A Parametric Approach to Solve Quadratic
Programming Prolemas with Fuzzy Environment in
the Set of Constraints
Carlos Cruz, Ricardo Coêlho Silva, José Luis Verdegay, Akebo
Yamakami
In: IFSA-EUSFLAT 2009 Proceedings-J. P. Carvalho, D. Dubois,
U. Kaymak and J. M. C. Sousa(Ed.) - ISBN: 978-989-95079-6-8
International Fuzzy Systems Association (IFSA) European Society
for Fuzzy Logic and Technology (EUSFLAT) Lisboa, Portugal Jul2009 pp:1158-1163
Quadratic programming can be seen both as
a general approach to linear programming and a
special class of nonlinear programming. Moreover,
Quadratic Programming problems are of utmost
importance in a variety of relevant practical fields,
such as, portfolio selection. This work presents and
develops a novel fuzzy-sets-based method that solves
a class of quadratic programming problems with
vagueness in the set of constraints. As vagueness is
natural and ever-present in real-life situations
requiring solutions, it makes perfect sense to attempt
to address them using fuzzy quadratic programming.
This kind of problem modeling is being applied in an
increasing variety of practical fields especially those
with logistics problems. Some illustrative numerical
examples illustrating the solution approach are solved
and analyzed to show the efficiency of this proposed
method.
Abstract:
Complex
Networks
A Controllabitlity Condition for the Existence of
Average Optimal Sttionary Policies of Linear
Stochastic Systems
Alessandro do Nascimento Vargas, João Bosco Ribeiro do Val
This paper establishes conditions for the
existence of optimal stationary policies for the longrun average cost control problem of linear stochastic
systems. The control takes a general structure in such
a manner that it contains, as particular case, a large
number of linear control problems. The main
contribution of this paper is to show that if (i) the
system is controllable to the origin and (ii) a technical
condition based on $epsilon$-optimal policies for the
discounted problem is verified, then there exists an
optimal stationary policy for the long-run average cost
problem. An example is presented to illustrate the
derived results.
Abstract:
Keywords: Stochastic control, Markov processes, Optimal
control
A Dynamic Artificial Immune Algorithm Applied to
Challenging Benchmarking Problems
Fabrício Olivetti de França, Fernando José Vonz Zuben
Keywords: Fuzzy sets, decision making, fuzzy mathematical
programming, quadratic optimization.
A Parametric Method to Solve Quadratic
Programming Problems with Fuzzy Costs
Ricardo Coêlho Silva, Carlos Cruz, Akebo Yamakami
In: International Fuzzy Systems Association (IFSA) and and the
European Society for Fuzzy Logic and Technology (EUSFLAT)
Lisboa, Portugal Jul-2009 pp:1-6
In many real-world scenarios, in contrast to
standard benchmark optimization problems, we may
face some uncertainties regarding the objective
function. One source of these uncertainties is a
constantly changing environment in which the optima
change their location over time. New heuristics or
adaptations to already available algorithms must be
conceived in order to deal with such problems. Among
the desirable features that a search strategy should
exhibit to deal with dynamic optimization are diversity
maintenance, a memory of past solutions, and a
multipopulation structure of candidate solutions. In
this paper, an immune-inspired algorithm that presents
these features, called dopt-aiNet, is properly adapted
to deal with six newly proposed benchmark instances,
and the obtained results are outlined according to the
available specifications for the competition at the
Congress on Evolutionary Computation 2009.
Abstract:
Keywords: Artificial Immune Systems, Optimization,
Dynamic Environments, Benchmark Functions
Abstract: This work describes a novel fuzzy-sets-based
method to solve a particular class of quadratic
programming problems which have vagueness
coefficients in the objective function. Quadratic
programming problems are of utmost importance in an
increasing variety of practical fields. In addition, as
the ambiguity and vagueness are natural and everpresent in real-life situations requiring solutions, it
makes perfect sense to attempt to address them using
fuzzy quadratic programming problems. Also, two
other methods to solve this kind of problems are
briefly described. The proposal uses two phases to
solve fuzzy quadratic programming problems. In the
first, phase we parametrize the fuzzy problem in
several classical alpha-problems with different cutting
levels. In the second, phase each of these alphaproblems is solved by using conventional solving
techniques. The final fuzzy solution to the problem is
obtained by integrating all of these particular alphasolutions. The results obtained using these two
methods are compared with the two-phased proposal
outlined above.
39
Keywords: Fuzzy sets, decision making, fuzzy mathematical
programming, quadratic optimization.
A Procedure To Model Biomass and Sugar
Accumulation Process By Fuzzy Systems.
André Pereira de Godoy, Gilmar Barreto, Fabio Cesar da Silva
In: The ISSCT - Agronomy Workshop
Uberlândia, MG May-2009 pp:1-3
The aim of this paper is to present a
procedure of identification and adjust a fuzzy model
for the one step ahead prediction of the process of
biomass and sugar accumulation of the sugarcane with
a level of errors inferior to those gotten by the
QCANE model. The most influent factors to be dealt
with in the procedure of model identification are
obtained through the literature studies and numerical
data analysis. During the process of identification, the
search is for a model with a smaller number of
parameters, that allows the user to understand in a
simple, clear way, the result of the simulation of the
model. To these processes results for discrete fuzzy
models are presented. The option for the use of the
fuzzy model for these processes is due to confirmation
of the expectation that this mathematical structure
could have a better performance in the prediction
using a reduced amount of parameters. The computer
results indicate the result of more accurate and precise
answers to the fuzzy models than to the QCANE
model considered the most precise model from the
literature in biomass and sugar accumulation of the
sugar cane estimation according to all the aspects set
for this work.
Abstract:
Keywords: fuzzy systems identification, Takagi- Sugeno
model, agricultural modelling, linear systems identification,
linear model analysis, QCANE model
Coevolutionary Genetic Fuzzy System to Assess
Multiagent Bidding Strategies in Electricity Markets
Igor Alexandre Walter, Fernando Antonio Campos Gomide
In: IFSA-EUSFLAT 2009 Proceedings-J. P. Carvalho, D. Dubois,
U. Kaymak and J. M. C. Sousa(Ed.) - ISBN: 978-989-95079-6-8
International Fuzzy Systems Association World Congress (IFSA)
European Society of Fuzzy Logic and Technology (EUSFLAT)
Abstract: In
this paper we study a genetic fuzzy system
approach to assess suitable bidding strategies for
agents in online auction environments. Assessing
efficient bidding strategies allows evaluation of
auction models and verification whether the
mechanism design achieves its goals. Day-ahead
electricity auctions are particularly explored to give an
experimental instance of the approach developed in
this paper. Previous works have reported successful
fuzzy bidding strategies developed by genetic fuzzy
systems and coevolutionary algorithms. Here we
review the coevolutionary algorithm and present
recent results of the bidding strategies behavior. We
analyze how the evolutionary strategies perform
against each other in dynamic environments.
Coevolutionary approaches in which coevolutionary
agents interact through their fuzzy bidding strategies
40
permit realistic and transparent representations of the
behavior of the agents in auction-based markets. They
also improve market representation and evaluation
mechanisms. Experimental results show that
coevolutionary agents can enhance their profits at the
cost of increasing system hourly price paid by
demand, an undesirable outcome from the perspective
of the buyers.
Keywords: Genetic fuzzy systems, electricity markets,
auctions, multiagent systems, computational economics
Control design for bilinear systems with a
guaranteed region of stability: an LMI-based
approach
Sophie Tarbouriech, Isabelle Queinnec, Taís Calliero Tognetti,
Pedro Luis Dias Peres
In: Mediterranean Conference on Control and Automation (MED)
Thessaloniki, Grécia Jun-2009 pp:809-814
This paper deals with the problem of
stabilizing a bilinear system with unstable open-loop
part by means of state feedback control. The implicit
objective is to provide an estimate of the region of
stability of the closed-loop system. The proposed
procedure can be decomposed into two convex
optimization problems described in terms of LMIs: i)
Given a polytope which bounds the values of the state,
containing the origin, find a stabilizing state feedback
control law and an associate region of stability as large
as possible inside the polytope. ii) For a solution of the
first problem, find the largest polytope containing the
ellipsoid such that the stability conditions hold. By
iterating these two steps, constructive conditions are
given to compute a state feedback control that
maximizes the estimate of the region of stability. The
results are illustrated by means of examples.
Abstract:
Keywords: Bilinear systems; State feedback control; Linear
matrix inequalities; Stability; Continuous-time
Control Variation as a Source of Uncertainty: Single
Input Case
André Du Pin Calmon, João Bosco Ribeiro do Val
In: American Control Conference - ACC
St. Louis, Missouri, USA Jun-2009 pp:1-6
Abstract: This paper presents a theoretical framework
and the control strategy for single input discrete-time
stochastic systems for which the control variations
increase state uncertainty (CVIU systems). This type
of system model can be useful in many practical
situations, such as in monetary policy problems,
medicine and biology, and, in general, in problems for
which a complete dynamic model is too complex to be
feasible. The optimal control strategy for a singleinput CVIU system associated with a convex cost
functional is devised using dynamic programming and
tools from nonsmooth analysis. Furthermore, this
strategy points to a region in the state space in which
the optimal action is of no variation, as expected from
the cautionary nature of controlling underdetermined
systems. In addition, a specific result for the case
when the cost functional is differentiable is obtained
Sinopse da FEEC
Keywords: condition monitoring, evolutionary neural
and discussed. These results are illustrated through a
numerical example in economics.
network, fault detection and diagnosis, genetic operators,
structural evolution.
Keywords: Stochastic systems, Optimal control, Control
applications
Definition of Fuzzy Pareto-optimality by using
Possibility Theory
Ricardo Coêlho Silva, Akebo Yamakami
In: International Fuzzy Systems Association (IFSA) and and the
European Society for Fuzzy Logic and Technology (EUSFLAT)
Pareto-optimality conditions are crucial
when dealing with classic multi-objective optimization
problems because we need to find out a set of optimal
solutions rather than only one optimal solution to
optimization problem with a single objective.
Extensions of these conditions to the fuzzy domain
have been discussed and addressed in recent literature.
This work presents a novel approach based on the use
of possibility theory as a comparison index to define a
fuzzily ordered set with a view to generating the
necessary conditions for the Pareto-optimality of
candidate solutions in the fuzzy domain. Making use
of the conditions generated, one can characterize fuzzy
efficient solutions by means of carefully chosen
single-objective problems. The uncertainties are
inserted into the formulation of the studied fuzzy
multi-objective optimization problem by means of
fuzzy coefficients in the objective function. Some
numerical examples are analytically solved to
illustrate the efficiency of the proposed approach.
Evolving Gradient a New Approach to Perform
Neural Network Training.
Celso Pascoli Bottura, César Daltoé Berci
In: 5th International Workshop on Artificial Neural Networks and
Intelligent Information Processing Workshop ANNIIP 2009
Itália Jul-2009 pp:1-3
The use genetic in ANNs is not a new
subject, several works have already accomplished
good results, however not competitive with procedural
methods for problems where gradient of the error is
well defined. The present document proposes an
alternative for ANNs training using GA(Genetic
Algorithms) to evolve the training process itself and
not to evolve directly the network parameters. This
way we get quite superior results and obtain a method
competitive with these, usually used do training
ANNs.
Abstract:
Abstract:
Keywords: neural network training, Genetic Algorithms,
evolving gradient
Evolving Granular Classification Neural Networks
Daniel Furtado Leite, Pyramo Pires da Costa Júnior, Fernando
Antonio Campos Gomide
In: IEEE International Joint Conference on Neural Networks
(IJCNN)
Atlanta-Georgia, EUA Jun-2009 pp:1736-1743
Abstract: The
objective of this study is to introduce the
concept of evolving granular neural networks (eGNN)
and to develop a framework of information
granulation and its role in the online design of neural
networks. The suggested eGNN are neural models
supported by granule-based learning algorithms whose
aim is to tackle classification problems in continuously
changing environments. eGNN are constructed from
streams of data using fast incremental learning
algorithms. eGNN models require a relatively small
amount of memory to perform classification tasks.
Basically, they try to find information occurring in the
incoming data using the concept of granules and T-S
neurons as basic processing elements. The main
characteristics of eGNN models are continuous
learning, self-organization, and adaptation to unknown
environments. Association rules and parameters can be
easily extracted from its structure at any step during
the evolving process. The rule base gives a granular
description of the behavior of the system in the input
space together with the associated classes. To illustrate
the effectiveness of the approach, the paper considers
the Iris and Wine benchmark problems.
Keywords: Possibility theory, multi-objective optimization,
fuzzy Pareto-optimality conditions, fuzzy mathematical
programming.
Evolutionary Neural Network Applied to Induction
Motors Stator Fault Detection
Daniel Furtado Leite, Romis Ribeiro de Faissol Attux, Fernando
José Von Zuben, Pyramo Pires da Costa Júnior, Fernando Antonio
Campos Gomide
In: IEEE International Electric Machines and Drives Conference
Miami -USA May-2009 pp:1-6
This paper addresses an induction motor
fault detection and diagnosis system. The system is
based on monitoring of key electrical signals
associated with an evolutionary artificial neural
network (EANN) model. Stator windings inter-turns
short-circuit have been successfully detected by the
system. This type of fault is one of the most frequent
in induction machines. The paper also discusses the
automatic design of artificial neural networks. A realencoding genetic algorithm has been suggested to
evolve architectures and weights of neural networks.
The genetic operators, mutation and recombination,
have been evaluated to obtain a consistent and
automatic
learning
algorithm.
Performance
comparisons on correct faults detection and memory
requirements provided by the evolutionary network
EANN and alternative nonlinear modeling techniques
have shown that EANN outperforms its counterparts.
Abstract:
Filtering of Discrete-Time Markov Jump Linear
Systems with Cluster Observation: An Approach to
Gilbert-Elliot's Network Channel
Andre R. Fioravanti, Alim Pedro de Castro Gonçalves, José
Cláudio Geromel
In: European Control Conference 2009 - ECC’09
41
Abstract: This paper addresses the H2 and the Hinfinity filtering design problems for linear systems
whose outputs are transmitted through a Markovian
channel. Previous works have used simplified GilbertElliot network channel models to address burst errors
in the output. We will use a generalized Gilbert- Elliot
model, increasing the number of Markov modes. With
this extended model it is not possible anymore to
know exactly what the Markov mode at every instant
of time is, but only that it belongs to a given subset we
call cluster. The design of the filter is done using
Linear Matrix Inequalities (LMIs).
Gain-scheduled H∞ control for discrete-time
polytopic LPV systems using homogeneous
polynomially parameter-dependent Lyapunov
functions
Jan de Caigny, Juan Francisco Camino dos Santos, Ricardo
Coração de Leão F. de Oliveira, Pedro Luis Dias Peres, Jan
Swevers
In: IFAC Symposium on Robust Control Design
IFAC Haifa, Israel Jun-2009 pp:-5
This paper presents H∞ performance
analysis and control synthesis for discrete-time linear
systems with time-varying parameters. The parameters
are assumed to vary inside a polytope and have known
bounds on their rate of variation. The geometric
properties of the polytopic domain are exploited to
derive parameter-dependent linear matrix inequality
conditions that consider the bounds on the rate of
variation of the parameters. A systematic procedure is
proposed to construct a family of finite-dimensional
relaxations based on Polya's Theorem and a
homogeneous polynomially parameter-dependent
parameterization of arbitrary degree for the Lyapunov
matrix. A numerical example illustrates the proposed
approach.
Abstract:
Keywords: Robust Nonlinear Control, LMI and Convex
Optimization
Gradiente das Partículas: Um novo Algoritmo de
Treinamento Utilizando uma Abordagem
Alternativa Via PSO
In: DINCON'2009 8th Brazilian Conference on Dynamics, Control
and Applications. Mai-2009
Resumo: A utilização de algoritmos baseados em
meta-heurísticas no treinamento de redes neurais
artificiais é um tema já conhecido e bastante
difundido. Muitos trabalhos já foram e vem sendo
realizados abrangendo o referido tema, tendo muitos
destes alcançados bons resultados. No entanto, apesar
dos esforços daqueles que se dedicam a esses etudos,
não se pode afirmar que, de forma genérica, existam
métodos de treinamento meta-heurísticos que
apresentem uma eficiência com relação a taxa de
convergência comparável a métodos procedurais,
principalmente quando gradiente do erro é bem
definido. Tendo em vista esse cenário, o presente
documento porpõe uma solução inovadora não antes
42
utilizada, a aplicação do método de otimização por
enxame de partículas na obtenção do vetor gradiente, e
não na otimização dos pesos de rede como é usual.
Essa abordagem leva a resultados claramente
superiores em taxa de convergência do treinamento,
sendo comparável com os métodos procedurais mais
rápido conhecidos atualmente.
Palavras-chave: Otimização por Enxame de Partículas,
Redes Neurais Artificiais, Otimização Não Linear
Gradiente Evolutivo: Um novo Método de
Treinamento Para Redes Neurais Tipo MLP
In: DINCON'2009 8th Brazilian Conference on Dynamics, Control
and Applications
Bauru, SP Mai-2009 pp:1-3
A utilização de algoritmos genéticos no
treinamento de redes neurais artificiais não é um
assunto novo, várias tentativas já foram realizadas
neste sentido obtendo bons resultudados, porém não
competitivos para problemas onde o gradiente do erro
é bem definido. O presente documento porpõe uma
alternativa ainda inexplorada para aplicação desses
algoritmos no treinamento de redes neurais, utilizando
AG(Algoritmos Genéticos) para evoluir o processo de
treinamento de rede e não o seu resultado,
conseguindo com isso resultados bastante superiores a
outras porpostas e tornando o método proposto
competitivo com técnicas procedurais de otimização,
usualmente utilizadas no treinamento de redes neurais.
Resumo:
Algoritmos Genéticos,
Gradiente, Treinamento de Redes MLP
Palavras-chave:
Método
do
H∞ filtering of networked systems with timevarying sampling rates
Renato Alves Borges, Ricardo Coração de Leão F. de Oliveira, C.
Abdallah, Pedro Luis Dias Peres
In: American Control Conference (ACC)
IEEE Control Systems Society St. Louis, Missouri, USA Jun-2009
pp:-5
In this paper, the problem of robust filter
design for networked systems with time-varying
sampling rate is investigated. The design conditions
are obtained by using the Lyapunov theory and the
Finsler's Lemma. A robust filter, that minimizes an
upper bound to the H∞ performance of the estimation
error, is obtained as the solution of an optimization
problem. A path-dependent Lyapunov function is used
in order to obtain less conservative design conditions.
Robust filters based on affine parameter-dependent
Lyapunov functions can be obtained as a particular
case of the proposed method. Numerical examples
illustrate the results.
Abstract:
Keywords: Networked control systems, Filtering, LMIs
Improving a Multi-Objective Multipopulation
Artificial Immune Network for Biclustering
Guilherme Palermo Coelho, Fabrício Olivetti de França, Fernando
José Von Zuben
Sinopse da FEEC
The biclustering technique was developed to
avoid some of the drawbacks presented by standard
clustering techniques. Given that biclustering requires
the optimization of at least two conflicting objectives
and that multiple independent solutions are desirable
as the outcome, a few multi-objective evolutionary
algorithms for biclustering were proposed in the
literature. However, apart from the individual
characteristics of the biclusters that should be
optimized during their construction, several other
global aspects should also be considered, such as the
coverage of the dataset and the overlap among
biclusters. These requirements will be addressed in
this work with the MOM-aiNet+ algorithm, which is
an improvement of the original multi-objective
multipopulation artificial immune network denoted
MOM-aiNet. Here, the MOM-aiNet+ algorithm will
be described in detail, its main differences from the
original MOM-aiNet will be highlighted, and both
algorithms will be compared, together with three other
proposals from the literature.
matrix inequality (LMI) conditions are provided for
the existence of a path-dependent Lyapunov function
which generalizes previous results based on affine
parameter-dependent Lyapunov functions. At each
sampling time the control law is obtained from a
convex optimization problem under LMI constraints.
As illustrated by examples, the proposed approach
yields less conservative results than other available
methods for MPC.
Abstract:
Keywords: Model predictive control; Linear parameter
varying systems; Parameter-dependent Lyapunov functions;
Linear matrix inequality relaxations
Particles Gradient: A New Approacha to Perform
MLP Neural Network Training basead on Particle
Swarm Optimization.
Celso Pascoli Bottura
In: 5th International Workshop on Artificial Neural Networks and
Intelligent Information Processing Workshop ANNIIP 2009
Itália Jul-2009 pp:1-3
The use of algorithms in neural networks
training is not a new subject Several works have
already accomplished good results, however not
competitive with procedural methods for problems
where the gradient of the error is well defined. The
present document proposes an alternative for neural
networks training using PSO (particle Swarm
Optimization) to evolve the training process itself and
not to evolve directly the network parameters as
usualy. This way we get quite superior results and
obtain a method clearly faster than others known
methods for training neural networks using heuristic
algoritms.
Abstract:
Keywords: Artificial Immune Systems, Biclustering, Multi-
Objective Optimization, Multi-Population
LMI relaxations for nonquadratic stabilization of
discrete-time Takagi-Sugeno systems based on
polynomial fuzzy Lyapunov functions
Eduardo Stockler Tognetti, Ricardo Coração de Leão F. de
Oliveira, Pedro Luis Dias Peres
In: Mediterranean Conference on Control and Automation (MED)
Mediterranean Control Association Thessaloniki, Greece Jun-2009
pp:7-12
Abstract: The
problem of state-feedback control design
for discrete-time Takagi-Sugeno fuzzy systems is
investigated in this paper. The strategy relies on the
use of a quadratic in the state Lyapunov function that
presents a homogeneous polynomial dependence of
arbitrary degree g on the first instant of time of the
premise variables and a multi-affine dependence on
the successive instants of time of the premise variables
until a maximum instant of time M. The tests cast in
the form of LMI relaxations parametrized on both g
and M and a feasible solution yields a non-PDC
controller based on homogeneous polynomial
matrices. Numerical examples show that the approach
can be less conservative and more efficient than other
methods available in the literature.
Keywords: neural network training, particle Swarm
Optimization, MLP network
Sliding Mode Control Approaches for an
Autonomous Unmanned Airship
Fábio Pereira Benjovengo, Ely Carneiro Paiva, Samuel Siqueira
Bueno, Paulo Augusto Valente Ferreira
In: AIAA Lighter-Than-Air Systems Technology Conference
Seattle, Washington May-2009 pp:1-6
This paper presents the research
developments for the global nonlinear control of an
autonomous airship, covering the full flight envelope
from hovering to aerodynamic flight. It focuses on the
longitudinal control of the airship using two different
Sliding Mode control techniques that are the classical
sliding mode and the unit vector approach. The design
methodologies for both techniques are presented along
with some representative simulation results.
Abstract:
Discrete-time systems, Linear matrix
inequalities, Takagi-Sugeno fuzzy models, Polynomial
Lyapunov functions
Keywords:
Model predictive control for linear parameter
varying systems using path-dependent Lyapunov
functions
Switched State Feedback Control for Continuous
Time Polytopic Systems and Its Relationship with
LPV Control
Marc Jungers, Rodrigo da Ponte Caun, Ricardo Coração de Leão
F. de Oliveira, Pedro Luis Dias Peres
In: IFAC Workshop on Control Applications of Optimisation (CAO)
Agora, Finlândia May-2009 pp:1-6
Grace Silva Deaecto, José Claudio Geromel
This paper is concerned with the design of
Model Predictive Control (MPC) for Linear Parameter
Varying (LPV) discrete-time systems. Sufficient linear
Abstract:
This paper treats switched control design of
polytopic systems. Our main goal is to calculate a set
of state feedback gains and a switching rule such that
the closed loop system remains globally
Abstract:
43
asymptotically stable for all uncertain parameter under
consideration, as well as a quadratic on the state
guaranteed cost is minimized. The minimum
guaranteed cost is assured by choosing, at each instant
of time, a feedback gain among a set of previously
calculated ones taking into account a multi-objective
criterion which allows the closed loop system to
present
different
and
possibly
conflicting
characteristics. The design conditions are based on
modified Lyapunov-Metzler inequalities that can be
solved by line search coupled to an LMI solver. It is
shown that the design technique can be viewed as an
alternative to a wide class of LPV control with the
clear advantage that the time-varying parameters do
not need to be measured online. The theoretical results
are illustrated by an academic example consisting of
two carts connected by a spring with spring constant
modelled as a time varying uncertain parameter.
The Brazilian Society Automatics - SBA Sociedade Brasileira de Automática.
Celso Pascoli Bottura, Carlos Eduardo Pereira
In: In: The 2009 IEEE Conference on The History of Techinical
Societies.
Philadelphia, EUA Jul-2009 pp:1-3
The Brazilian Automatics Society (SBASociedade Brasileira de Automática) was established
in 1975 to promote the science and engineering of
automation and control in Brazil. Currently SBA has
more than 700 members (professionals, students, and
organizations) being responsible for the organization
of the major South-American academic event in the
area of automatic control, the Brazilian Automation
conference (Congresso Brasileiro de Automática CBA), as well as the Brazilian Symposium on
Intelligent Automation (SBAI - Simposio Brasileiro de
Automação Inteligente). Additionaly SBA co-sponsors
events in other areas, such as robotics and neural
networks. SBA is coordinated by a Board of Directors
and a Council and includes six Techinical Comittees
(Industrial Automation, Intelligent Systems, Robotics,
Instrumentation, Power Eletronics, and Power
Systems). SBA has one affiliated jounal, revista
Controle e Automação. (Control and Automation
Journal).
Abstract:
Keywords: Sociedade Brasileira de Automática, Brazilian
Society of Automatics, Automation and Control, Automatic
Control
Train Regulation for Mass Transit Systems
Wagner Schalch Mendes, Rafael Santos Mendes
Abstract: The train regulation problem is of particular
importance among the scheduling problems found in
mass transit systems, being characterized by trains
running in urban regions taking passengers from one
location to another. If the desired headway between
trains, dwell-times in platforms and running times
between platforms are determined and known apriori,
44
the steady state solution (timetable) can be calculated.
However, real systems are subject to disturbances such
as passengers preventing doors from closing,
mechanical or electrical failures, etc., that can deviate
the trains from the steady state. In this context, this
work is concerned with the determination of a control
law, i.e. a law for the determination of the arrival and
departure times of each train on each platform in the
system's cycles in order to reestablish and maintain the
timetable (reference solution). The proposed control
law is based on max-plus algebra concepts. The
desired arrival and departure times of each train on
each platform are calculated from the last occurrence
instants of the system's events and from a set of
matrices defined in max-plus algebra.
Keywords: Transportation systems, Discrete event systems,
Petri nets
Uninetworks in Time Series Forecasting
Michel Hell, Fernando Antonio Campos Gomide, Rosangela
Ballini, Pyramo Pires da Costa Júnior
In: 28th North American Fuzzy Information Processing Society
Annual Conference (NAFIPS2009) - ISBN: 978-1-424445776
Cincinnati, Ohio - USA Jun-2009
This paper presents an approach for time
series forecasting using a new class of fuzzy neural
networks called uninetworks. Uninetworks are
constructed using a recent generalization of the classic
and and or logic neurons. These generalized logic
neurons, called unineurons, provide a mechanism to
implement general nonlinear processing and introduce
important characteristics of biological neurons such as
neuronal AND synaptic plasticity. Unineurons achieve
synaptic and neuronal plasticity modifying their
internal parameters in response to external changes.
Thus, unineurons may individually vary from an and
neuron to an or neuron (and vice-versa), depending
upon the necessity of the modeling task. Besides, the
proposed neural fuzzy networks are able to extract
knowledge from input/output data and to encode it
explicitly in the form of if-then rules. Therefore,
linguistic models are obtained in a form suitable for
human understanding. Experimental results show that
the models proposed here are more general and
perform best in terms of accuracy and computational
costs when compared against alternative approaches
suggested in the literature.
Abstract:
A Multi-Terminal Pressure Sensor with enhanced
sensitivity
Guilherme Coraucci, Marcia Rautemberg Finardi, Fabiano Fruett
In: The 15th International Conference on Solid-State Sensors,
Actuators & Microsystems - Transducers 2009 - ISBN:
9781424441938
Denver, EUA Jun-2009 pp:1122-1125 doi:
10.1109/SENSOR.2009.5285927
This paper describes the design,
microfabrication and characterization of a CMOS
compatible Multi-Terminal Pressure Sensor (MTPS).
Abstract:
Sinopse da FEEC
This sensor is an alternative to the pressure sensors
based on the conventional silicon Wheatstone
piezoresistive bridge (WB) or four-terminal
piezotransducers. The layout of the MTPS is designed
in such a way that the sensor sensitivity is effectively
improved and the short-circuit effects, which are
modeled by the Geometrical Correction Factor (G),
can be minimized. The sensor design was supported
by Finite Element Method (FEM). The MTPS
sensitivity amounts to 4,8 mV/psi.
Keywords: Pressure sensor, CMOS Microsystem, shortcircuit effect, piezoresistive effect, high sensitivity,
microelectronic.
component. The electronic system data are registered
and processed by software that to extract the necessary
parameters to characterize this effect in a
communication systems.
Ni-P, Ni-B and SiO2 as materials for hard mask in
deep silicon etching for MEMS fabrication using
ICP reactor
A. M. Nunes, Moshkalev, S. A., Clóvis Fischer, Peter Jurgen Tatsch,
Alexander Flacker
In: 24th Symposium on Microelectronics Technology and Devices SBMicro 2009
SBMICRO Natal, RN Aug-2009 pp:1-8
Abstract: Ni-P, Ni-B and SiO2 films were used as hard
mask materials in Si etching using a high-density
inductively coupled plasma (ICP) reactor for MEMS
fabrication. The Ni-P and Ni-B films were deposited
using an electroless method, and the SiO2 film was
thermally grown in a conventional furnace. Two
etching processes were used to characterize the masks.
The first uses SF6/Ar gas mixture varying bias power
and process time, and the second is a Bosch like
process, using C4F8 as a passivation gas. The Ni-P
mask showed the highest resistance to etching, being
applicable in Si deep etching (>m); while the
SiO2ƒÝ100 mask was found to be less resistive,
especially under strong ion bombardment (high bias
power). The Ni-B mask was found to be highly
porous, resulting in formation of micropillars during
ecthing, which may be interesting for some
apllications such as sensors.
Development of an Electromechanical Sensor
System to Monitor Sports Activities
Yull Heilordt Henao Roa, Fabiano Fruett
In: 9th International Conference on Electronic Measurement &
Instruments - ICEMI 2009 - ISBN: 978142438631
Beijing, China Aug-2009 pp:4-10 doi: 10.1109/ICEMI.2009.5274657
This paper proposes the development of a
low cost electronic non-invasive comfortable
prototype based on acceleration and rotation
microelectromechanical (MEMs) sensors for obtaining
physiological measures during training or regular
physical activities of a chosen athlete. In this paper we
present the prototype system; The system for
acquisition, calibration and testing of accelerometer
(SACTA) and some preliminary field tests.
Abstract:
Keywords: Accelerometer, Sport Sensing, Real Time
Feedback, Wireless Communication.
GPS Independent time Transfer Technique on a
Wireless Telecommunication Link
Carlos Nazareth Motta Marins, Pierre Kaufmann, Antônio A. A.
Ferreira Júnior, Marcelo Carneiro de Paiva, Jacobus Willibrordus
Swart, Adonias Costa da Silveira
In: VIII Seminário Internacional de Metrologia Elétrica - VIII
SEMETRO - ISBN: 9788586920066
João Pessoa, Paraíba Jun-2009 pp:1-3
Abstract: We present a newly conceived clock system
based on time-to-digital converter (TDC) principle to
generate, transfer and compare time coded sequences
(TCS) with nanoseconds accuracy, using a wireless
telecommunication link. Comparison provided
midterm stability comparable to good OCXO
oscillators showing the feasibility of a low cost, GPS independent technique, exhibiting highly performing
stability.
Keywords: Mask Materials, Etching, MEMS
Planar Inductor for RFICs Surrounded by Metallic
Vias Forming a Cavity-backed Struture Improving
Isolation from the Circuitry
Silvio Ernesto Barbin, Luiz Carlos Kretly
In: XXVI PIERS - Progress In Electromagnetics Research
Symposium, 2009
Moscow, Russia Aug-2009 pp:219
New JITTER Measurement Technique Using tdc
Principle in a FPGA Component
Carlos Nazareth Motta Marins, Pierre Kaufmann, Antônio A. A.
Ferreira Júnior, Marcelo Carneiro de Paiva, Jacobus Willibrordus
Swart
In: VIII Seminário Internacional de Metrologia Elétrica - VIII
SEMETRO
João Pessoa, Paraíba Jun-2009 pp:10-14
Abstract: The paper presents a new approach for
measure and analysis of jitter. The measures are made
with the Time to Digital Converters with an electronic
implementation that uses VHDL language in a FPGA
Abstract: Planar Inductors are very useful devices for
high performance RFICs. There are several methods to
increase their Quality Factors and Inductance to values
required by the designer in many cases. However, due
to specific silicon properties and electromagnetic
fields interactions with the substrate, several undesired
effects between those devices and the CMOS circuitry
arise. This work presents a new structure that
surrounds the planar inductor core using via holes and
N+ sinkers aiming at shielding it effectively and using
the same additional strategies employed for improving
the Q and expand the L values. Shielding planes
(polysilicon and n+ buried layer) are placed vertically
in the structure connecting these two types of feedthrough to a guard ring located at the uppermost
surface providing an efficient current path between the
ground pads. The overall shape looks like a cavitybacked configuration. An interesting study carried out
by Kouzaev [1] introduces a semi-analytical
electromagnetic model of a ground square-pad via-
45
hole based on previous cavity theory. This model can
be extended or adapted to the n+ sinker. The vertical
configuration associated with the via-holes and N+
sinkers has a second order influence
The influence of Poly-Si/SiGe gate in CMOS
transistors for RF and microwave circuit
applications
Hugo Ricardo Jimenez Grados, Leandro Tiago Manêra, M. F.
Rautemberg, José Alexandre Diniz, Ioshiaki Doi, Peter Jurgen
Tatsch, Hugo E. H. Figueroa, Jacobus Willibrordus Swart
In: 12th International Conference on the Formation of
Semiconductor Interfaces - ICFSI 2009
Weimar, Alemanha Jul-2009 pp:1-3
A reduction of gate depletion and DC
characteristics in CMOS transistors with poly-Si/SiGe
Gate stack fabricated with local CMOS process is
presented. Our local CMOS process uses a single n+
doped, poly-Si/SiGe gate material. After deposition,
both the poly-Si and the SiGe used as gate layers were
implanted by phosphorus ions. The parameters on
threshold, sub-threshold and low frequency noise 1/f
of poly-Si/SiGe CMOS transistors are reported. Our
results demonstrate that the shift in threshold voltage
due to the presence of Ge in the gate material is
apparent from the p-MOS and n-MOS device
characteristics. The drive current turn-on in the I-V
characteristics increases compared with conventional
CMOS transistors with poly-Si gate and devices show
low 1/f noise which make them promising devices for
RF and microwave circuit applications.
Abstract:
A Network Architecture for Mobile Robotics
Paulo Rodolfo da Silva Leite Coelho, Daniel de Haro Moraes, Eleri
Cardozo, Eliane Gomes Guimarães, Thienne de Melo e Silva
Mesquita Johnson, Fernanda Cristina Adabo Atizani
In: Simpósio Brasileiro de Redes de Computadores e Sistemas
Distribuídos - SBRC´2009
Recife, Pernambuco May-2009 pp:1-6 doi:
10.4108/ICST.ROBOCOMM2009.5821
Mobile robotics environments must adopt
networking solutions that provide secure and reliable
communications for the mobile robots across wide
areas such as hospitals, factories, farms, etc. This
paper proposes a network architecture for large mobile
robotic environments built above the existing
networking infrastructures. The architecture builds an
overlay network above the already deployed network.
The overlay network must fulfill the requirements
demanded by mobile robotic applications, mainly,
communication continuity during handover, security,
and quality of service. A prototype of this architecture
was implemented and evaluated in a mobile robotic
environment composed of Pioneer P3-DX mobile
robots accessed through the Internet. Results from
simulation show that the architecture scales well in
larger networking scenarios.
Abstract:
46
An Investigation of Java Faults Operators Derived
from a Field Data Study on Java Software Faults
Tânia Basso, Bruno Pacheco Sanches, Mario Jino, Regina Lucia de
Oliveira Moraes,
In: Workshop de Tolerância a Falhas - SBC
João Pessoa Aug-2009 pp:1-13
Abstract: The knowledge of real software faults
representativeness is important to allow the emulation
of software faults in a more accurate way through
software fault injection techniques. This paper
presents a field data study to analyze the
representativeness of Java software faults, including
security faults. The faults are classified according to a
previous field study of C faults representativeness and
new types of faults are identified due to the specific
characteristics of the Java language structure. Results
are compared and show that the mistakes most
commonly made by programmers follow a pattern,
independent of the programming language.
Java software faults,
representativeness of faults, field study
Keywords:
security
faults,
DGridE – Sistema de Gerenciamento para
Compartilhamento e Comercialização de Recursos
em um Desktop Grid
Lourival Aparecido de Gois, Walter da Cunha Borelli
In: VII Workshop on Computational Grids and Applications
(WCGA)
Recife, Pernambuco Mai-2009 pp:93-94
Resumo: Este artigo propõe estratégias destinadas à
modelagem de um sistema de gerenciamento de
recursos denominado DGridE - Desktop Grid
Economy,
fundamentado
nos
princípios
microeconômicos que orientam os mercados
tradicionais de bens e serviços. Esta abordagem
permitiu a estruturação de um mercado de recursos
computacionais através da utilização de mecanismos
para formação de preços, negociação intra e inter
cooperativas e controle das transações comerciais
decorrentes dos processos de compartilhamento.
Learning Bayesian networks to perform feature
selection
Pablo Alberto Dalbem de Castro, Fernando José Von Zuben
In: IEEE International Conference on Communications - 2009
Dresden, Alemanha Jun-2009 pp:467-473
Bayesian networks have been widely applied
to the feature selection problem. The existing
approaches learn a Bayesian network from the
available dataset and, afterward, utilize the Markov
Blanket of the target feature as the criterion to select
the relevant features. The Bayesian network learning
can be viewed as a search and optimization procedure,
where a search mechanism explores the space of all
network structures while a scoring metric evaluates
each candidate solution based on the likelihood. This
paper investigates the application of an immuneinspired algorithm as the search procedure for
obtaining high-quality Bayesian networks, motivated
by the dynamical control of the population size and
diversity along the search. Due to the resulting
Abstract:
Sinopse da FEEC
multimodal search capability, in a single run of the
algorithm several subsets of features are obtained.
Experiments on ten datasets were carried out in order
to evaluate the proposed methodology in classification
problems, and reduced-size subsets of features were
produced.
Keywords: feature selection; Bayesian networks; Markov
blanket; artificial immune systems; classification problems.
Electrical Energy
A Comparative Analysis of FBD, PQ and CPT
Current Decompositions Part I: Three-Phase ThreeWire Systems
Helmo K. M. Paredes, Fernando P. Marafão, Luiz Carlos Pereira
da Silva
In: IEEE Bucharest Power Tech Conference, 2009
Bucareste, Romenia Jun-2009 pp:1-6
This paper investigates the main similarities
and discrepancies among three important current
decompositions proposed for the consideration of
unbalanced and/or non-linear three-phase three-wire
power circuits. The considered approaches were the so
called FBD Theory, the pq-Theory and the
Conservative Power Theory (CPT), recently presented
by Tenti et al Such decompositions and related
definitions may influence the power measurement
techniques, revenue metering, instrumentation
technology and also power conditioning strategies.
The three methods have been summarized, discussed
and compared by means of computational simulation.
Although the three methods are based on different
concepts, the results obtained under ideal conditions
are very similar. The main differences appear in the
presence of unbalanced and non-linear load
conditions. Under linear unbalanced conditions, both
FBD and pq-Theory suggest that the some current
components contain a third-order harmonic. Besides,
neither pq-Theory nor FBD method are able to provide
accurate information for reactive current under
unbalanced and distorted conditions, what can be done
by means of the CPT-Theory. The paper tries to
explain the causes of these differences in terms of the
decomposition’s foundations and the resulting
waveforms and spectra.
Abstract:
Towards a Landmark-based Flat Routing
Ricardo Pasquini, Fábio Luciano Verdi, Maurício Ferreira
Magalhães
In: Simpósio Brasileiro de Redes de Computadores e Sistemas
Distribuídos - SBRC´2009
Recife May-2009 pp:1-6
Two main groups of Flat Routing proposals
are found in the literature. The biggest group considers
the existence of an underlay network providing direct
communication between neighbors at the flat identity
layer. On the other hand, a smaller set of proposals
consider a scenario that has none underlay network,
i.e., routing directly on flat identifiers/names. Our
interest is concentrated on the second group due to the
perspective of a new internetworking model in which
the network layer has no information regarding
location and, in this paper, our Landmark-based Flat
Routing proposal is introduced. We also present a tool
for evaluating different topologies and flat routing
protocols. The quantitative results show the signaling
overhead and the trade-off between routing table size
and route stretch. The results were collected using the
tool under two distinct topologies, a regular mesh and
an Internet-like topology.
Abstract:
Keywords: Flat Routing, Landmark, XOR-based Routing
Um modelo de sistema de aprendizagem
colaborativa apoiado por computador com ênfase
em trabalho em equipe
Ana Aparecida Simões Da Cunha, Léo Pini Magalhaes
In: Congresso da Sociedade Brasileira de Computação (CSBC
Bento Gonçalves, RS Jul-2009 pp:1575-1584
Apesar da presença crescente de equipes de
trabalho e de sua importância nas corporações, 50%
das iniciativas de trabalho em equipe falham pois os
profissionais não estão preparados para atuar de forma
colaborativa. Isso indica que não apenas as habilidades
técnicas, mas também as sociais deveriam ser
aprendidas na escola. Este artigo descreve um modelo
para um ambiente de aprendizagem colaborativa, em
que os estudantes são estimulados a se ajudar
mutuamente para desenvolver as habilidades sociais,
característica não encontrada em nenhum dos sistemas
de aprendizagem avaliados. Após uma revisão de
princípios teóricos de colaboração é proposto um
modelo para aprendizagem colaborativa em equipe.
Resumo:
Keywords: FBD theory, pq-Theory, Homo-variables,
harmonics, current decomposition, power theory.
A Specialized Genetic Algorithm To Solve The
Short Term Transmission Network Expansion
Planning
Luis A. Gallego, Marcos Julio Rider Flores, Rubén Augusto
Romero Lázaro, Ariovaldo Verandio Garcia
In: IEEE Power Tech 2009
Bucareste- Romênia Jun-2009 pp:1-6
In this paper, the short term transmission
network expansion planning (STTNEP) is solved
through a specialized genetic algorithm (SGA). A
complete AC model of the transmission network is
used, which permits the formulation of an integrated
power system transmission network expansion
planning problem (real and reactive power planning).
The characteristics of the proposed SGA to solve the
STTNEP problem are detailed and an interior point
method is employed to solve nonlinear programming
problems during the solution steps of the SGA. Results
of tests carried out with two electrical energy systems
show the capabilities of the SGA and also the viability
of using the AC model to solve the STTNEP problem.
Abstract:
47
Keywords: Transmission network expansion planning, AC
model of the transmission network, specialized genetic
algorithm, mixed integer nonlinear programming, interior
point method.
Adaptative Single-Phase Autoreclosing Based on
Harmonic Signature of the Secondary Arc Voltage
Allan Alves Montanari, Maria Cristina Dias Tavares, Carlos
Medeiros Portela
In: IPST/09 International Conference on Power Sistems Transients
Kyoto, Japão Jun-2009 pp:1-6
This paper presents an adaptative SinglePhase Auto Reclosure (SPAR) scheme to minimize
protection dead time. The proposed method detects the
extinction of the secondary arc. Computer simulation
and secondary arc field tests were combined to
improve the performance of adaptative SPAR for
various secondary arc current levels. The
PSCAD/EMTDC program together with measured
secondary arc data were used to simulate secondary
arc on the system. The harmonic content of the
secondary arc voltage was analyzed with Short Time
Discrete Fourier Transform (STDFT). The proposed
algorithm is based on the characteristics of the odd
order harmonics of the faulted voltage. The algorithm
determined the secondary arc extinction and gave the
order to reclose the circuit breaker. A properly
designed control can be responsible for taking the
decision on whether the fault is a permanent one or a
transient fault, and if the transient one has
extinguished, i.e. whether to trip the other sound
phases or to reclose the faulted phase after the
secondary arc extinction.
Abstract:
Keywords: Adaptative autoreclosing, secondary arc
extinction, dead time, harmonic analysis, non-permanent
faults.
Computer Aided System for Managing, Controlling
and Analyzing Data from Hydroelectric Plants
Ieda Geriberto Hidalgo, Darrel G. Fontane, Secundino Soares
Filho, Marcelo Augusto Cicogna
In: World Environmental and Water Resources Congress 2009:
Great Rivers © 2009 ASCE
Kansas City Missouri, EUA Mai-2009 pp:4749-4757
This paper presents a computer aided system
for managing, controlling and analyzing data from
hydroelectric plants. The proposed system consists of
three modules. The first is a relational database that
organizes, standardizes and manages data from
hydroelectric plants. The second module allows a user
to build, store and manage advanced queries on this or
certain other databases. The third is a simulator of the
hydroelectric plants operation which can be used for
planning the future operation or reproducing the past
operation. The computational implementation of these
modules uses the Object-Oriented Paradigm, the C++
Programming Language and the Structured Query
Language (SQL). The data manager, the queries
builder and the simulator were tested with data from
Brazilian hydroelectric plants and the results show the
potential of this system for the analysis and
Resumo:
48
consistency evaluation of data from hydroelectric
plants.
Palavras-chave: Data analysis, Hydroelectric plants,
Simulation, Object- oriented paradigm, Structured Query
Language.
Control of Power Electronic Interface for
Renewable Energy Sources Under Distorted Grid
Voltage
Rodolfo Manuel Moreno Martinez, Luiz Carlos Pereira da Silva,
Sérgio Pires Pimentel, José Antenor Pomílio
In: 2nd International Conference on Clean Electrical Power ICCEP
Capri, Itália Jun-2009 pp:404-414
In this paper a Power Electronic Interface
(PEI) to integrate up to two renewable energy sources
is presented. Through the control of the DC link
terminal voltage and the AC terminal voltage of the
voltage source converter (VSC) the generation of the
different distributed sources can be adapted to the grid,
supplying the local load and exporting energy to the
grid. The system was analyzed under distorted grid
voltage, where the quality of the grid current is
affected. Solutions based on the use of resonant
passive filters and injection of harmonics to
compensate the distortion of the grid voltage is
presented.
Abstract:
Keywords: Harmonic compensation, power electronic
interface, renewable energy source, resonant passive filter,
and voltage source converter.
Distribution Network Planning Using a Constructive
Heuristic Algorithm
Marina Lavorato de Oliveira, Marcos Julio Rider Flores. Ariovaldo
Verandio Garcia, Rubén Augusto Romero Lázaro
In: IEEE PES 2009 General Meeting Proceedings
Calgary, Canadá Jul-2009 pp:1-6
An optimization technique to solve
distribution network planning (DNP) problem is
presented. This is a very complex mixed binary
nonlinear programming problem. A constructive
heuristic algorithm (CHA) aimed at obtaining an
excellent quality solution for this problem is
presented. In each step of the CHA, a sensitivity index
is used to add a circuit or a substation to the
distribution network. This sensitivity index is obtained
solving the DNP problem considering the numbers of
circuits and substations to be added as continuous
variables (relaxed problem). The relaxed problem is a
large and complex nonlinear programming and was
solved through an efficient nonlinear optimization
solver. A local improvement phase and a branching
technique were implemented in the CHA. Results of
two tests using a distribution network are presented in
the paper in order to show the ability of the proposed
algorithm.
Abstract:
Keywords: Distribution network planning, constructive
heuristic algorithm, mixed binary nonlinear programming,
power systems optimization, KNITRO, AMPL.
Sinopse da FEEC
Ecolig - A semiotic protocol that uses
neuroheadsets and CP-Nets
Abstract: The connection of generators on distribution
feeders may cause significant impact on the steadystate performance of the network. Quantification of
the impacts on power losses, in a systematic way, is a
difficult task due to the complexity of network
operation since generators can operate with different
lead and lag power factors and, occasionally, can
inject variable active power on the network. This
paper evaluates the impact of distributed generators on
the active and reactive power losses of the system by
using a sensitivity-based method. From one base case
power flow solution it is possible to estimate the active
and reactive power losses for a new generator installed
at any bus of the system, for any combination of active
power injection, and also for any operating power
factor. The effects of varying the location, generation
level and operating mode of the generators can be
easily assessed by using the analytical method.
Moreover, a numerical index to quantify the impact of
multi-distributed generators on power losses is also
proposed. The method is applied to a 70-bus
distribution network. The simulations results are
compared with those obtained by the repetitive power
flow solutions in order to validate the results obtained
by the sensitivity-based method.
Paulo Victor de Oliveira Miguel e Gilmar Barreto
In: Proceedings of World Conference on Educational Multimedia,
Hypermedia and Telecommunications 2009-AACE - Association for
the Advancement of Computing in Education(Ed.)
Honolulu, HI, USA Jun-2009 pp:667-673
Abstract: Human sensing, perception, consciousness
and interactions can help a learning process. In this
way the human-machine interface with an appropriate
protocol can be an important part of an interactive
educational project. An intelligent communication
code can minimize the computational effort to send
and receive information between human being and
electronic equipments. The ECOLIG, a semiotic
protocol, which encapsulates the path of knowledge,
should be used to make Object-Sign and ObjectInterpreter consistent relations. Connecting ionic
structures to electric devices it can be a new
communication paradigm in e-learning. In summary,
learn how to share the internal mind space can be a
great challenge when using the CP-Nets (Colored Petri
Networks) and Brain Machine Interfaces for an
efficient knowledge exchange.
Keywords: e-learning, Semiotic, HMI, Embedded Systems,
Hybrid Networks, Sensorial Protocol, Petri Network.
Keywords: Distributed generation, distribution networks,
sensitivity analysis, power system losses.
Evaluation of Technical Losses Estimation in LV
Power Distribution Systems
Leonardo Mendonça Oliveira de Queiroz, Celso Cavellucci,
Christiano Lyra Filho
In: 20th International Conference and Exhibition on Electricity
Distribution (CIRED - ISBN: 978-1-84919126-5
Praga - República Tcheca Jun-2009 pp:1-4
Abstract: This paper proposes a methodology to
estimate technical losses in low voltage (LV)
distribution systems. Its main contribution is the
development of regression models able to estimate
technical losses with low levels of information about
the network. Regression models are used to predict
one variable (dependent variable) from one or more
variables (independent variables). The dependent
variable is the technical loss, and the independent
variables are any data that allows characterizing a LV
network. Different sets of independent variables are
evaluated, with respect to two scenarios: a distribution
company and the regulatory agency. Independent
variables are analyzed with respect to relevance (given
by the value of statistical correlation), availability and
auditability. An analysis of the regression models and
of the set of independent variables is also presented.
Exemplos de Experiências de EaD Realizadas por
Docentes e Pesquisadoreas da Unicamp: Vídeos de
Eletrotécnica Uma Experiência da FEEC.
Gilmar Barreto
In: Workshop "EaD Unicamp"
Campinas, SP Mai-2009 pp:1-3
Keywords: Technical Losses, Power Distribution Systems,
Regression Models
Evaluation of the Impact of Distributed Generation
on Power Losses by Using a Sensitivity-Based
Method
Hugo Murici Ayres, Luiz Carlos Pereira da Silva, Walmir de
Freitas Filho, Madson Cortes de Almeida, Vivaldo Fernando da
Costa
In: IEEE PES General Meeting, 2009
Resumo: Este trabalho destaca a importância da
elaboração e utilização de vídeos didáticos
principalmente em disciplinas exclusivamente com
aulas teóricas como é o caso da disciplina ET016 –
Eletrotécnica ministrada na Faculdade de Engenharia
Elétrica e de Computação – UNICAMP. Esta
disciplina é obrigatória e oferecida para os alunos das
Faculdades de Engenharia de Alimentos, Engenharia
Agrícola, Engenharia de Controle e Automação,
Engenharia Mecânica e Engenharia Química. Nesta
disciplina são abordados conceitos básicos de
eletricidade; circuitos monofásicos e trifásicos;
produção, transmissão e utilização da energia elétrica;
princípios físicos e principais aplicações de
transformadores; máquinas elétricas de indução,
assíncrona e corrente contínua; e conceitos básicos de
instalações elétricas e dispositivos de proteção. Ao
elaborar e disponibilizar estes vídeos no "youtube",
visamos despertar um maior interesse nos alunos e
motivá-los a complementar e consolidar o conteúdo
ministrado nas aulas teóricas presenciais.
Palavras-chave: Circuitos de Corrente Alternada,
Eletrotécnica, Ensino de Engenharia, Vídeos Didáticos.
49
High Frequency Parameters of Small Three-Phase
Induction Motors for Operation with PWM Inverters
Rudolf Ribeiro Riehl, Ernesto Ruppert Filho
In: International Electric Machines and Drives Conference
(IEMDC)
Miami, Florida May-2009 pp:1352-1357
The subject of this paper is to present a
simple method to determine the high frequency
parameters of three-phase induction motors, up to 10
HP to be used in studies involving PWM variable
speed drives where it is necessary to check the effects
caused to the motor by the electromagnetic
interference (emi) both in the differential mode as well
as in the common mode. The method proposed here
consists in the identification of the motor equivalent
electrical circuit parameters both in rated frequency
and also in high frequency through characteristic tests
performed in the laboratory together the use of
characteristic equations and curves, shown in the
references, to determine the motor high frequency
parasite capacitances and also through system
simulations, using dedicated software, like Pspice, to
determine the characteristic waveforms involved in the
differential and common mode phenomenon and
comparing with the experimental results in the
common mode phenomena, validating the proposed
procedure
Abstract:
induction motors,
parameters, PWM inverters
Keywords:
emi,
high
frequency
Identifying critical sets in state estimation using
Gram matrix
Madson Côrtes de Almeida, Eduardo Nobuhiro Asada, Ariovaldo
Verandio Garcia
Bucareste, Romenia Jun-2009 pp:1-6
This paper presents a numerical algorithm
for the identification of critical measurements and
critical sets in power system state estimation. The
proposed algorithm is based on the use of Gram matrix
constructed considering the rows of the measurement
Jacobian matrix as vectors. This paper shows some
features of the Gram matrix that can be useful in the
optimal planning of metering systems for power
system state estimation. Numerical examples with a 6bus system and also with IEEE-14 system are used for
testing the proposed algorithm.
Abstract:
Keywords: critical measurements, critical sets, Gram
matrix, redundancy analysis, state estimation.
Ill-conditioned Optimal Power Flow Solutions and
Performance of Non-Linear Programming Solvers
Manfred Fritz Bedriñana Aronés, Marcos Julio Rider, Carlos
Alberto de Castro Junior
In: IEEE Power Tech Conference
Romenia Jun-2009 pp:1-6
In this paper, the performance of the most
popular non-linear programming solvers (e.g. IPOPT,
KNITRO, LOQO, MINOS and SNOPT) is evaluated
for applications in power systems and treatment of illconditioned systems related to Optimal Power Flow
Abstract:
50
(OPF) solutions. Regarding the applications, the
maximum loading point problem modeled as an
optimization problem is used as an OPF example.
Also, it is used to describe the ill-conditioned OPF
solutions, the sensitivity matrices obtained in the OPF
process, and conditions related to linear independence
(LI) loss singularity analysis. Simulations using a
simple two-bus and IEEE test systems are carried out
to evaluate the performance of solvers for solving LI
loss singularity cases, which were obtained upon the
original data systems. Some of the Lagrange
multipliers corresponding to the constraints tend to
infinity when the LI condition is violated, which
implies that the OPF solution is ill-conditioned. In this
case, the number of iterations increases (convergence
problems) significantly for all solvers, and some
solvers presented oscillatory process.
Keywords: Maximum loading point, voltage stability, load
flow analysis, step size optimization.
Investigation of the Islanding Detection of
Induction Generators
Diogo Salles Corrêa, Paulo César Magalhães Meira, Ahda
Pionkoski Grilo Pavani, Walmir de Freitas Filho, Jose Carlos de
Melo Vieira Junior, Wiliun Xu
In: 2009 IEEE PES General Meeting
This paper provides an analysis of the
performance of the under/over frequency and
under/over voltage relays for islanding detection of
squirrel-cage induction generators. This analysis is
based on the nondetection zones, which are
determined by extensive dynamic simulations using
PSCAD/EMTDC. The presented nondetection zones
are constructed considering different reactive power
compensation and different detection times. Analysis
on the nondetection zones is developed, and the
influence of the required detection time and of the
reactive power compensation on the nondetection zone
is highlighted
Abstract:
Keywords: Induction generator, anti-islanding protection,
and nondetection zones.
Long-Term Hydropower Scheduling Based on
Deterministic Nonlinear Optimization and Annual
Inflow Forecasting Models
Monica de Souza Zambelli, Ivette Raymunda Luna Huamani,
Secundino Soares Filho
Bucharest, Romenia Jun-2009 pp:1-8
Abstract: This
paper proposes an operational policy for
long-term hydropower scheduling based on
deterministic nonlinear optimization and annual inflow
forecasting models using an open-loop feedback
control framework. The optimization model precisely
represents hydropower generation by taking into
consideration water head as a nonlinear function of
storage, discharge and spillage. The inflow is made
available by a forecasting model based on a fuzzy
inference system that captures the nonlinear
correlation of consecutive inflows on an annual basis,
Sinopse da FEEC
method with step size optimization (LFSSO). The
process is characterized by obtaining consecutive
approximations of the MLP within the infeasible
region. Since the feasibility boundary contour in the
neighborhood of the MLP may not be smooth, some of
the computed approximations may fall within the
feasible region. In an earlier paper, a mechanism based
on binary search was used to drive the operating point
back to the infeasible region. A new load curtailment
method to improve the proximity towards feasibility
boundary guaranteeing that the next solution will lay
within the infeasibility region is the main contribution
of this paper. Reactive power generation limits are
taken into account. The proposed formulation requires
information as the normal vector and power
mismatches, and results in a better convergence path
towards MLP in comparison with the original version
of the method presented earlier. Simulation results for
IEEE test systems are shown to validate the proposed
method.
then disaggregating it on a monthly basis. In order to
focus on the ability of the approach to handle the
stochastic nature of the problem, a case study with a
single-reservoir
system
is
considered.
The
performance of the proposed approach is evaluated by
simulation over the historical inflow records and
compared to that of the stochastic dynamic
programming approach. The results show that the
proposed approach leads to a better operational
performance of the plant, providing lower spillages
and higher average hydropower efficiency and
generation.
Keywords: fuzzy inference systems, inflow forecasting,
long-term
hydro-thermal
scheduling,
optimization, stochastic dynamic programming
nonlinear
Maintenance Resources Allocation on Power
Distribution Networks with a Multi-objective
Framework
Fábio Luiz Usberti, José Federico Vizcaino González, Christiano
Lyra Filho, Celso Cavellucci
In: CTW Cologne-Twente Workshop on Graphs and Combinatorial
Optimization-Sonia Cafieri, Antonio Mucherino, Giacomo
Nannicini, Fabien Tarissan, Leo Liberti(Ed.)
Paris, França Jun-2009 pp:317-320
Utilities must supply energy with good
reliability levels. In Brazil, reliability indicators, such
as maximum values for the *system average
interruption frequency index* (*SAIFI*), are establish
and supervised by the Brazilian Electricity Regulatory
Agency, for each group of networks operated by a
distribution company in a geographical area; large
fines are applied for violation. This work represents
the relationship between maintenance activities and
reliability as a minimization problem with two criteria:
cost of maintenance activities and maximum value for
the *SAIFI,* along the planning period. The solution
of the problem for each local network gives the local
*efficient solutions* and the associated *trade-off*
curves. Local solutions are optimally combined to
solve higher levels multiple criteria optimization
problems, unveiling *efficient solutions* and
associated *trade-off* curves for each group of
networks and for the whole company. Therefore, the
methodology provides information to avoid fines and
to assess good decisions on maintenance activities.
Abstract:
Keywords: Network Optimization, Integer Non-Linear
Problem, Pareto Frontier
Keywords: Maximum loading point, voltage stability, load
flow analysis, step size optimization
Optimal Placement of Voltage Regulators in
Distribution Systems
Carlos A. N. Pereira, Carlos Alberto de Castro Junior
Bucharest, Romania Jun-2009 pp:1-6
Abstract: A two-step algorithm for the optimal
placement of voltage regulators in distribution systems
is presented in this paper. In the first step, voltage
regulators are placed (and the tap position is
determined) at candidate buses, aiming at minimizing
voltage drops and real power losses. In the second
step, an attempt to reduce the number of voltage
regulators is made, taking into consideration
economical aspects (minimization of installation and
maintenance costs). It is shown that the proposed
algorithm is fast, efficient and provides reliable
results.
Keywords: Voltage regulators, distribution systems,
voltage control, loss minimization, cost minimization.
Secondary Arc Harmonic Content for Various
Current Levels Based on Field Tests
Allan Alves Montanari, Maria Cristina Dias Tavares, Carlos
Medeiros Portela, Alessandra Benevides Camara,
In: IPST/09 International Conference on Power Sistems Transients
Kyoto, Japão Jun-2009 pp:1-6
New Method Based on Load Flow with Step Size
Optimization for Calculating the Maximum Loading
Point
Beatriz de Lima Tavares, Manfred Fritz Bedriñana Aronés, Carlos
Alberto de Castro Junior
IEEE-PES Bucharest, Romenia Jun-2009 pp:1-6
In this paper, an improved maximum loading
point (MLP) calculation method is proposed. The
calculation process is based on the properties of the
normal vector to the feasibility boundary computed
close to MLP, which is calculated by a load flow
Abstract:
In this paper the harmonic content of
measured secondary arc current and voltage between
the arc terminals were analyzed by the application of
the Short Time Discrete Fourier Transform (STDFT).
The algorithm is based on shifting a window on the
signals (voltage and current) and computing the
coefficients of the STDFT. The measurements were
performed on a large number of field tests realized at
CEPEL High Power Laboratory in Brazil. It was
possible to identify a harmonic signature of the
Abstract:
51
“secondary arc” produced in the field tests and some
extrapolation can be made for actual secondary arc.
to be very efficient in terms of computational costs,
and both unit commitment and generation schedules.
Keywords: Secondary arc extinction, harmonic analysis,
single-phase autoreclosing, non-permanent faults.
Keywords: Hydroelectricity, operation scheduling, unit
Selective Current Compensators Based on the
Conservative Power Theory
Helmo K. M. Paredes, Fernando P. Marafão, Luiz Carlos Pereira
da Silva
In: IEEE Bucharest Power Tech Conference, 2009
Bucareste, Romênia Jun-2009 pp:1-6
Abstract: This paper presents possible selective current
compensation strategies based on the Conservative
Power Theory (CPT). This recently proposed theory,
introduces the concept of complex power conservation
under non-sinusoidal conditions. Moreover, the related
current decompositions results in several current
terms, which are associated with a specific physical
phenomena (power absorption P, energy storage Q,
voltage and current distortion D). Such current
components are used in this work for the definition of
different current compensators, which can be selective
in terms of minimizing particular disturbing effects.
The choice of one or other current component for
compensation directly affects the sizing and cost of
active and/or passive devices and it will be
demonstrated that it can be done to attend predefined
limits for harmonic distortion, unbalances and/or
power factor. Single-phase compensation strategies
will be discussed by means of the CPT and simulation
results will demonstrate their performance.
Short-term hydropower scheduling via an
optimization-simulation decomposition approach
Makoto Kadowaki, Takaaki Ohishi, Leonardo Silveira de
Albuquerque Martins, Secundino Soares Filho
Romênia Jun-2009 pp:1-6
Abstract: This paper presents a decomposition
approach based on an optimization-simulation
approach to short-term hydropower scheduling. The
problem is formulated as a mixedinteger nonlinear
programming problem where the decision variables
are the power output and the number of units
committed at each hydro plant and hour of the day or
week ahead. The goal consists of maximizing
hydropower
efficiency
while
reducing
startup/shutdown costs and attaining system load,
operational constraints, as well generation targets
established by mid-term operation scheduling models.
The approach proposed in this paper solves a relaxed
version of the original problem in which hydraulic
constraints are ignored. Eventual hydraulic
infeasibilities are computed by a simulation step in
order to either validate the solution or add violated
constraints back into the problem. The approach is
implemented and tested over the Brazilian power
system for a study case comprised of 95 hydro plants,
447 generating units, and an average load of 41 GW
for a week long horizon. Results confirm the approach
52
commitment, nonlinear programming, simulation
Simulation and Experimental Studies on Double-fed
Induction Generator Power Control Operating at
Sub-Syncronous Speed
Alex Pereira França, Rogério Vani Jacomini, Edson Bim
In: Internation Conference on Power Electronics and Drive
Systems
Taipei, TAYWAN May-2009 pp:1-3
Two control schemes for active and reactive
power of a double-fed induction generator with the
stator connected direct to the constant frequency, three
phase grid are described. First the direct and
quadrature rotor current components are generated
based on the mathematical model of the machine. The
second scheme used a PI controller to generate the
rotor current reference components. The principles of
both schemes are described in detail in this paper with
a strong experimental approach. A complete
simulation model is developed and several studies are
performed to test its under different conditions. A
laboratory test setup consisting of a wound rotor
induction machine and driven by a variable speed
squirrel cage induction motor is used to validate the
control schemes proposed and the simulation results.
Abstract:
Keywords: PI controller, active power control, double-fed
induction generator power control, asynchronous
generators, machine control, reactive power control,
laboratory test setup, mathematical model, quadrature rotor
current components, rotor current
Step Size Optimization Based Interior Point
Algorithm: Applications and Treatment of Illconditioning in Optimal Power Flow Solutions
Manfred Fritz Bedriñana Aronés, Carlos Alberto de Castro Jr.
In: 2009 IEEE PES General Meeting
In this work a step size optimization based
nonlinear Interior Point (IP) algorithm is proposed for
applications in power systems and treatment of illconditioned systems related to Optimal Power Flow
(OPF) solutions. Regarding the applications, the
maximum loading point problem modeled as an
optimization problem is used as OPF example. Also, it
is used to describe the ill-conditioned OPF solutions,
the sensitivity matrices obtained in the OPF process,
and conditions related to singularity analysis.
Simulations using a simple test system are carried out
to evaluate its performance for solving ill-conditioned
systems in comparison to conventional IP methods.
The proposed method provides a better convergence
path towards well-conditioned optimal solution; it also
presents more information (step size, Lagrange
multipliers, eigenvalue analysis) in case the optimal
point is singular or infeasible, which is classified as
ill-conditioned optimal solution.
Abstract:
Sinopse da FEEC
Keywords: Power system optimization, interior point
to the previous model and validate it, with examples
from the metrics found in literature and also with the
results of a case study applied in Metropolitan
Broadband Access Network in Pedreira, a city located
in the state of São Paulo, Brazil.
algorithms, step size optimization, ill-conditioned systems,
maximum loading point.
A TV Digital Interativa na Era Convergente das
Comunicações Sem Fio
André Barbosa Filho, Luis Geraldo Pedroso Meloni
In: XXXII Congresso Brasileiro de Ciências da Comunicação
Curitiba, PR Jul-2009 pp:1-14
Resumo: Vivemos a era da convergência das
tecnologias digitais, onde o recente sucesso da
implantação do sistema brasileiro de televisão digital
vai de encontro às tecnologias de comunicação sem fio
na Internet, pavimentando o caminho da aguardada
interatividade plena. Um importante desafio se
apresenta com a possibilidade do país assumir um
papel de liderança na definição de um novo perfil de
operação do WiMAX abaixo de 1 GHz, denominado
WiMAX-700. Ao desempenhar um papel promissor
como canal de interatividade do SBTVD, amplia as
possibilidades de produção de conteúdos audiovisuais
digitais que, por sua vez, colaboram no esforço do
conjunto de programas de inclusão social do País.
An Architecture for Environmental Monitoring and
Control in Municipal Scale
Felipe Marques Pires, Rodrigo Sanches Miani, Leonardo de Souza
Mendes
In: International Conference on Wireless Information Networks and
Systems - Winsys 2009
Milão, Italia Jul-2009 pp:27-31
Abstract: Advances in smart sensors, communication
technologies and embedded computing allow to have
an interaction between digital and physical worlds.
This paper presents an architecture of combining
ZigBee with Metropolitan broadband access networks
in order to build an architecture for monitoring and
control in a municipal scale. A prototype alarm system
was implemented based on this architecture as a proof
of concept. However there is a wider range of
applications that can be designed using this
architecture to provide reliable services for
government and communities.
Palavras-chave: Sistema brasileiro de televisão digital,
interatividade plena, conexão Internet.
Achievable Rate Region for the Gaussian MIMOMAC with Cooperating Encoders
Jaime Portugheis, Gustavo Fraidenraich
In: Tenth International Symposium on Communication Theory and
Applications - ISCTA
Ambleside, United Kingdom Jul-2009 pp:1-6
Aplicações Governamentais para TV Digital Móvel
usando Ginga NCL
Edwar Andres Velarde Allazo, Vicente Idalberto Becerra Sablon,
Yuzo Iano
In: Congresso de Tecnologia de Televisão SET2009
São Paulo, SP Ago-2009 pp:1-5
This paper presents the technologies required
for the implementation of interactive applications in
the m-government area of mobile digital TV. For its
development, we use the declarative environment of
Ginga middleware of the Brazilian Digital Television
System (SBTVD) and Lua, as an imperative language
that allows mathematical processing, data handling
and, especially, the application of an interactivity
channel. In order to provide interaction, the use of
Ginga NCL is required for portable devices on a
particular platform. The present proposal aims at
employing it in a scenario set to the dialogue between
government and population.
Resumo:
This paper considers a Gaussian two-user
multiple-input multiple-output (MIMO) multipleaccess channel (MAC) with cooperating encoders.
After defining a form of cooperation strategy we
derive achievable rate bounds by applying the results
obtained by Willems for the MAC with generalized
feedback. Then we characterize an achievable rate
region by giving lower and upper bounds which are
close together. The results obtained generally exceed
the capacity region of a MIMO MAC without
cooperation.
Abstract:
Keywords: Multi-User Information Theory, Cooperative
Communications
An Alternative Approach for Formula Modelling in
Security Metrics
Rodrigo Sanches Miani, Felipe Marques Pires, Leonardo de Souza
Mendes
In: International Conference on Security and Cryptograp SECRYPT 2009
Milão, Itália Jul-2009 pp:381-386
Palavras-chave: Middleware, Ginga-NCL, Interativity, m-
government.
Avaliação da Análise Cepstral Generalizada
Aplicada à Modelagem de Vogais
Ramiro Roque Antunes Barreira, Fabio Violaro
In: 7o Congresso de Engenharia de Áudio da AES Brasil
São Paulo-SP Mai-2009 pp:1-6
This paper proposes an alternative approach
to modelling the formula attribute within the context
of security metrics. This approach seeks to correct past
errors by treating a security metric like a set, and
inserting a component that addresses the set
intersection between the security elements. The work
consists in to define the model, explain the differences
Abstract:
Resumo: A análise cepstral generalizada é um ma
abordagem unificada que inclui como casos
particulares, dois métodos de análise de fala
extensamente utilizados: as análises LP e cepstral. Na
abordagem unificada, a atribuição de valor a um
parâmetro γ, pode produzir r os casos LP (γ =-1),
cepstral (γ =0), assim com mo análises com perfis
intermediários (-1<γ <0). A escolha de γ influencia na
53
modelagem das ressonâncias e anti-ressonâncias
produzidas no trato vocal quando excitado pela glote.
Para se avaliar a modelagem do o espectro de fala pela
análise cepstral generalizada, o método foi aplicado a
diferentes vogais, atribuindo-se diversos valores a γ.
Palavras-chave: Análise cepstral generalizada
Bivariate Nakagami-q (Hoyt) Distribution
Rausley Adriano Amaral de Souza, Michel Daoud Yacoub
New, exact expressions for the bivariate
Nakagamiq (Hoyt) processes with arbitrary correlation
in a nonstationary environment are derived. More
specifically, the following are obtained: joint
probability density function, joint cumulative
distribution function, power correlation coefficient,
and some statistics related to the signal-to-noise ratio
at the output of the selection combiner, namely, outage
probability and probability density function. The
expressions are mathematically tractable and flexible
enough to accommodate a myriad of correlation
scenarios, useful in the analysis of a more general
fading environment.
Abstract:
Keywords: Nakagami-q (Hoyt), Bivariate Distribution,
Correlation, Combiner.
Concatenated ZCZ Codes on CDMA Ad Hoc
networks
Tarciana Araujo Lopes, Márzio Geandre da Silva Rego, Renato
Baldini Filho
Applications - ISCTA'09
Ambleside, Reino Unido Jul-2009 pp:1-6
This work analyzes the performance of
concatenated zero correlation codes (ZCZ) on CDMA
ad hoc networks. The presented study focus on a
quasi-synchronous single-hop system achieved with a
rough synchronization. In the proposed ad hoc
network model, a possible combination of processing
codes is carefully chosen to provide a performance
enhancement, taking advantage of the interference free
window (IFW). Simulation results using these
spreading codes show to improve the performance of
CDMA ad hoc networks in a multipath fading
scenario.
Abstract:
Keywords: ZCZ codes, ad hoc.
Distributed Power Control for QoS-flexible Services
in Wireless Communication Networks.
Fabiano Sousa Chaves, Mohamed Abbas-Turki, Hisham AbouKandil, João Marcos Travassos Romano
In: 17 Mediterranean Conference on Control and Automation
Thessaloniki, Grécia Jun-2009 pp:1-6
This paper proposes a distributed power
control framework for wireless communication
networks that is able to provide a flexible QoS with
the introduction of a dynamic target QoS into a
conventional (fixed) target tracking power control
algorithm. The target QoS of individual terminals is
automatically updated according to a given
Abstract:
54
performance criterion. The distributed power control is
formulated as a Linear Quadratic Regulator (LQR)
problem, where system operating points are met
according to channel quality and the choice of key
parameters. Effectiveness of the LQR-based power
control is analyzed and the influence of such
parameters on the algorithm’s performance is
investigated with the help of computer experiments.
Keywords: Distributed power control, adaptive QoS,
wireless systems, LQR control
Efficient Traffic Routing for Current and Future
Demands in Optical Networks
Karcius Day Rosário Assis, Kelly Cristina da Cruz Silva, Marcio
Sáenz Savasini, Helio Waldman
In: 11 International Conference on Transparent Optical
Networking - ICTON 2009 - ISBN: 9781424448265
Azores, Portugal Jul-2009 pp:1-4
We propose a linear formulation for traffic
routing in optical networks after the Virtual Topology
Design (VTD). The formulation maximizes the
amount of traffic the network is able to accept,
through minimizing the residual capacity in
established lightpaths. The results suggest that it is
feasible to preserve enough open capacity to avoid
disruption of connections and blocking of future traffic
demands in networks with scarce resources.
Abstract:
Keywords: optical networks, lightpath routing, virtual
topology
Estimating the Number of Audio Sources in a
Stereophonic Instantaneous Mixture
Everton Zaccaria Nadalin, Ricardo Suyama, Romis Ribeiro de
Faissol Attux
In: 7o Congresso de Engenharia de Áudio da AES Brasil
São Paulo Mai-2009 pp:1-6
Resumo: In this work, we propose a method to count
and locate sources in an underdetermined
instantaneous mixture of audio signals in the stereo
case. The main idea is to explore the sparseness and
the mutual independence that most of the audio
sources have. The proposed ICA/SCA-based
algorithm has an interesting advantage with respect to
other SCA solutions in that some of the sources do not
necessarily need to be sparse.
Palavras-chave: Sparse component analysis, independent
component analysis, blind identification, audio signal
processing
Estudos sobre uma Ferramenta de Classificação
Automática de Gêneros Musicais
Erica Moura Pereira, Jayme Garcia Arnal Barbedo, Amauri Lopes
In: 7º Congresso de Engenharia de Áudio da AES Brasil
São Paulo, SP Mai-2009 pp:1-8
Resumo: Este trabalho apresenta alguns estudos sobre
um classificador automático para sinais musicais
proposto na literatura, o qual se distingue pelas
soluções inovadoras e pelo desempenho. Os objetivos
foram as análises da viabilidade de ampliação da
aplicabilidade do classificador em taxonomias
distintas daquela usada pelos autores e da
possibilidade de redução do esforço computacional
Sinopse da FEEC
para treinamento. Os estudos sobre aplicabilidade
usaram uma taxonomia menor que a original e o
desempenho alcançado foi similar a àquele presente na
literatura. Concluímos, então, que o classificador pode
se aplicado a taxonomias distintas daquela original. O
novo processo de treinamento proposto permitiu
reduzir o esforço computacional e ainda manter o
desempenho original do classificador.
Improved method for evaluation of Network
Protection and Throughput in optically Switched
Metropolitan Networks
Indayara Bertoldi Martins, Luiz Henrique Bonani, Felipe Rudge
Barbosa, Edson Moschim
In: The Fifth Advanced International Conference on
Telecommunications
Venice, Itália May-2009 pp:1-4
Abstract: In this work we investigate the performance
of optical packet/burst switched (OPS/OBS)
architectures connected as mesh and as ring
topologies, for future optical metropolitan networks.
Network throughput and protection to link failure
under uniform traffic distribution for all nodes is
investigated in order to evaluate the sensitivity of
OPS/OBSN performance. Our results are based on
analysis of simulations and comparison between
various mesh (Manhattan St. type) and ring topologies.
We also consider the detailed traffic distributions over
the network links and the impact caused by failure of
more or less loaded links, thus providing a way to
select links that require protection.
classificação de sinais musicais,
processamento de sinais de áudio, processamento digital de
sinais.
Palavras-chave:
Evaluation of Quality and Security of a VoIP
Network based on Asterisk and OpenVPN
Dherik Barison, Rodrigo Sanches Miani, Leonardo de Souza
Mendes
In: International Conference on Security and Cryptograp SECRYPT 2009
Milão, Itália Jul-2009 pp:144-147
Abstract: The proposed work is to verify the
performance and security of different cryptographic
algorithms in a encrypted VPN (Virtual Private
Network), created to provide confidentiality in the
network VoIP traffic. The performance tests of the
algorithms will occur in various network scenarios,
simulating some problems like latency, packet loss,
out of order packets, among others. The test
architecture consists of: use of the SIPp software for
communication between clients, an Asterisk server to
intermediate the calls and the OpenVPN software,
which will be responsible to create the virtual private
network and provide the cryptography necessary for
this work.
Keywords: Photonic Switching, Network Protection,
Optical Fiber Communications
Interference Mitigation Using Widely Linear Array
Adilson Chinatto, Cynthia Cristina Martins Junqueira, João
Marcos Travassos Romano
In: 17 EUSIPCO 2009 - European Signal Processing Conference
Glasgow, Escócia Aug-2009 pp:1-6
Abstract: Widely Linear Processing (WLP), proposed
by Brown and Crane in 1969, has recently received a
great deal of attention, in particular due to its potential
of application in some important problems in array
processing. The present work investigates the
implementation of the linearly constrained minimum
variance (LCMV) algorithm proposed by Frost in the
context of widely and strictly linear processing. The
results are compared with those obtained via MVDR
widely and strictly linear processing.
Generalização de emparelhamento de arestas de
polígonos hiperbólicos relacionados à tesselação
{12g-6,3}
Mercio Botelho Faria, Reginaldo Palazzo Jr.
In: Colóquio Brasileiro de Matemática.
Rio de Janeiro, RJ Jul-2009 pp:1-6
Resumo: O principal objetivo deste trabalho é apresentar a
generalização de três emparelhamentos de arestas de polígonos com
12g-6 arestas representando superfícies de Riemann compactas,
orientáveis de gênero g. Mostramos que todos os ciclos de vértices
têm comprimento 3 sendo, portanto, domínios fundamentais da
tesselação {12g-6, 3}. Sabemos que para g = 2 existem somente
oito emparelhamentos. Para g = 3, 4 e 5 o número de
emparelhamentos tem 5, 7 e 10 dígitos, respectivamente. A
relevância deste problema está associada à relevância do problema
de empacotamento de esferas com implicações importantes em
codificação de canal bem como na construção de constelações de
sinais digitais. A relevância de tais resultados para o
empacotamento de esferas, está no fato que um reticulado
hiperbólico do tipo {12g - 6, 3} fornece um empacotamento ótimo
com relação à densidade de empacotamento no plano hiperbólico e,
portanto, relacionado a códigos reticulados com probabilidade de
erro mínima, equivalentemente, códigos ótimos. Por outro lado,
para g → ∞ as densidades de empacotamento e de cobertura, do
referido reticulado, atingem o valor máximo apresentado por Toth.
Daí, nosso interesse em explorar os emparelhamentos de arestas de
polígonos, em particular os polígonos hiperbólicos com 12g-6
arestas que estejam associados à tesselação {12g-6, 3}.
Keywords: Widely linear Processing, Array Processing,
Interference Mitigation
MATVOX - Compilador de Uso para Deficientes
Visuales
Julián Mauricio Prada Sanmiguel, Luiz Cesar Martini
In: 5th IEEE Colombian Workshop on Robotics and Automation CWRA
Bogotá, Colombia Jul-2009 pp:1-3
Palavras-chaves:
Emparelhamento de arestas de
polígonos hiperbólicos, códigos geometricamente uniformes,
empacotamento de esferas, geometria hiperbólica.
The lack of computational mathematics with
applications designed for the visually impaired has not
allowed these people to study and perform work in
areas of the exact sciences. This paper describes
mainly the development of a mathematical compiler,
which allows visually impaired people can implement
mathematical algorithms from the text editor of a free
program called DOSVOX available specifically for
people with special needs.
Resumo:
inclusão
calculadora programável.
Palavras-chave:
digital,
deficiente
visual,
55
Multi-Hop Aggregate Information Efficiency in
Wireless Ad Hoc Networks
Pedro Henrique Juliano Nardelli, Giuseppe Abreu, Paulo Cardieri
We introduce multi-hop aggregate
information efficiency (MIEA), a comprehensive
metric that captures several performance-affecting
factors of wireless ad hoc networks in a unified
formulation. This metric is then employed to analyze
such networks with respect to their spectral
efficiencies, network loads, and hopping strategies.
The analysis reveals that the hopping strategy that
achieves maximum information efficiency is that of
multiple short hops with no more than a single packet
retransmission allowed at each hop, as opposed to the
alternative of fewer long-haul hops with multiple
packet retransmissions. The implementation of that
preferred strategy withstanding, it is found
furthermore that the most efficient networks typically
exhibit about 65% of link outage probability, which
corroborates similar findings obtained in different
network settings and using different metrics. Bearing
in mind that link outage is a function not only of
deterministic parameters such as node density, but also
of design parameters such as modulation, our analysis
also shows that the modulation scheme that optimizes
the aggregate information efficiency is in fact a
function of node density. In that respect, our metric
and method is shown to be useful to determining the
modulation scheme that optimizes the performance of
a network with a certain node density.
Abstract:
Keywords: aggregate information efficiency, ad hoc
networks, multi-hop transmission, performance analysis.
Numerical Modeling Challenges for Guide-Wave
Photonic Device Simulations
Hugo Enrique Hernández Figueroa, Marcos Sérgio Gonçalves,
Luciano Prado de Oliveira
In: Photonics North 2009-Réal Vallée(Ed.)
Quebec, Canadá May-2009 pp:1-6
An overview of current research efforts to
reduce the computer time of the solution of sparse
linear systems and to develop stable explicit schemes
with unstructured meshes will be discussed in this talk.
A way to overcome such challenges involve the
proposal of new finite element functions which satisfy
local conservation laws, able to improve the sparse
matrices conditioning and capable to eliminate the
spurious solutions which are responsible for the
instability of time domain propagation schemes.
Abstract:
Keywords: waveguides, computational electromagnetics,
finite elements, photonics, integrated optics
On Performance of Channel Estimation Algorithms
for STC-OFDM Systems in Non-linear Channels
Luciano Leonel Mendes, Renato Baldini Filho
Applications - ISCTA
Ambleside, Reino Unido Jul-2009 pp:1-6
56
Abstract: Generally, a linear interpolation al-gorithm is
applied between adjacent pilot subcarriers to estimate
the overall frequency response of OFDM channel.
However, the mobility of the receiver and the nonlinearity introduced by the power amplifier at the
transmitter can affect significantly the performance of
the linear interpola-tion algorithms. The aim of this
paper is to analyze the performance of those
algorithms in presence of non-linearities, mobility and
space-time diversity.
Non-linear
estimation, diversity.
Keywords:
channels,
OFDM,
chan-nel
Power Control with Adaptive QoS for Wireless
Communications Networks
Fabiano Sousa Chaves, Mohamed Abbas-Turki, Hisham AbouKandil, João Marcos Travassos Romano
A distributed automatic control solution for
power allocation of wireless communication networks
is proposed in this paper. The objective is to combine
the best features of both conventional and
opportunistic power control, namely, fairness and
opportunism on the QoS provision. In a first step, the
Distributed Power Control (DPC) problem is
formulated as a Linear Quadratic Regulator (LQR)
problem. Desired QoS and transmitter power are
introduced in the model and an autonomous adaptive
operation mode is designed to allow suitable operation
under different network conditions. In the sequence,
methods of mixed H2/H-infinity control are applied to
provide robust, but not overconservative algorithms.
Computer simulations illustrate the capability of the
proposed algorithms in managing the trade-off
between fairness and opportunism, so as their
robustness with respect to practical impairments.
Abstract:
Keywords: Distributed power control, adaptive QoS, mixed
H2/H-infinity control, wireless systems
Process Recognition of Human Íris: Fast
Segmentation Approach
Roger Fredy Larico Chávez, Vicente Idalberto Becerra Sablon,
Yuzo Iano
In: IV SIACG 2009 - IV Iberoamerican Symposium in Computer
Graphics
Isla Margarita, Venezuela Jun-2009 pp:228-235
In order to develop a fast algorithm for iris
recognition, it.s necessary to properly acquire and
segmentate the image with little loss of information. In
this work, we present a detailed algorithm of fast
segmentation of the texture of the iris. To achieve that,
it is used an iterative search outline of the centers and
concentric rays, as well as an application of Gaussian
noise and medium filters to get reliable results. The
achieved results are compared with the published
algorithms and evaluated. The algorithm presents
superior performance in relation to processing speed
as well as an improvement of the recognition
precision.
Abstract:
Sinopse da FEEC
Keywords: Iris Recognition, biometric, algorithms,
segmentation, detection of circles, processing of signs.
Self-Adaptive Distributed Power Control for
Opportunistic QoS Provision in Wireless
Communication Networks
Fabiano Sousa Chaves, João Marcos Travassos Romano, Mohamed
Abbas-Turki, Hisham Abou-Kandil
In: SPAWC 2009 - The 10th IEEE Workshop on Signal Processing
Advances in Wireless Communications
Perugia, Italia Jun-2009 pp:1-6
Abstract: Emerging wireless communication networks
are required to provide data services which tolerate
large variations of link quality. Such applications
allow flexible power control procedures. In this paper,
we approach the distributed power control problem
from an automatic control point of view. A new
framework for opportunistic power control is
proposed, where the target quality of service at each
link is determined by a linear quadratic regulator
controller according to a given self-adaptive criterion.
Stability and convergence of proposed framework are
analytically guaranteed, while its performance is
confronted with other algorithms through computer
simulations.
que reúne artigos de profissionais que ministraram
aulas nos cursos de Estruturação de Núcleos de
Inovação Tecnológica.
Unsupervised Signal Processing: Deconvolution,
Indentification, and Separation.
Romis Ribeiro De Faissol Attux,Charles Casimiro Cavalcante,Joao
Marcos Travassos Romano,Ricardo Suyama
Taylor & Francis Group - ISBN: 9780849337512
CRC Press Aug-2009 pages:340
Abstract:
Unsupervised
Signal
Processing:
Deconvolution, Identification, and Separation provides
a unified and systematic presentation of topics such as
blind
equalization,
source
separation,
and
unsupervised as well as nonlinear adaptive filtering.
Extending classical results in literature, this book
addresses new issues on static and dynamic
convergence of Bussgang algorithsm. It explores
emergent trends like neuro-fuzzy systems and
evolutionary algorithms. The text pays special
attention to the equivalence relations between the
different unsupervised criteria, including the
relationships with Wiener theory. It also includes
applications to wireless communications and MIMO
systems.
Keywords: Distributed power control, adaptive QoS,
wireless systems, LQR control
TV Digital Móvil utilizando Middleware Ginga-NCL
en Aplicaciones de Gobierno Electrónico
Vicente Idalberto Becerra Sablon, Edwar Andres Velarde Allazo,
Yuzo Iano
In: 7 LACCEI 2009, Seventh LACCEI International Latin American
and Caribbean Conference
San Cristobal, Venezuela Jun-2009 pp:1-6
Electrical Energy
Máquinas Elétricas e Acionamento
Edson Bim
Campus - ISBN: 8535230297
Editora Elsevier Rio de Janeiro v:1 Jul-2009 pages:480
Máquinas Elétricas e Acionamento é livrotexto base para a disciplina Máquinas Elétricas e
Conversão Eletromecânica de Energia presente em
todos os cursos de Engenharia Elétrica. Com uma
linguagem mais próxima ao aluno, ricamente ilustrado
e utilizando diversos exemplos de máquinas elétricas
existentes no mercado brasileiro, o livro cobre toda a
ementa da disciplina e ainda estende a abrangência
para os alunos interessados em ampliar seus
conhecimento.
Dentro os tópicos desenvolvidos no livro estão
Circuitos Magnéticos, Transformadores, Princípios de
Conversão Eletromecânica de Energia, Configuração
básica e Princípios de Máquinas Elétricas, Máquinas
de Corrente Contínua, Máquinas de Indutância,
Geração de Torque e até uma introdução ao controle
vetorial de máquinas.
Resumo:
Abstract: Este artículo presenta las tecnologías
necesarias para la implementación de aplicaciones
interactivas en el área de M-Government sobre TV
digital móvil, para su implementación utiliza el
ambiente declarativo del middleware del Sistema
Brasilero de Televisión Digital (SBTVD), donde la
utilización del Ginga-NCL es obligatorio en
dispositivos portátiles sobre una plataforma particular,
proponiendo su utilización en un escenario, de dialogo
entre el gobierno y la población.
Keywords: Middleware, Ginga-NCL, Interactiva, Android,
M-Government.
Book
Automation
Transferência de Tecnologia – Estratégias para a
Estruturação e Gestão de Núcleos de Inovação
Tecnológica
Palavras-chave: Circuitos Magnéticos, Transformadores,
Princípios de Conversão Eletromecânica de Energia,
Configuração básica e Princípios de Máquinas Elétricas,
Máquinas de Corrente Contínua, Máquinas de Indutância,
Geração de Torque, Controle vetorial de máquinas.
Marli Elizabeth Ritter dos Santos, Patricia Tavares Magalhaes de
Toledo, Roberto de Alencar Lotufo
Editora Komedi Jun-2009 pages:353
O livro Transferência de Tecnologia –
Estratégias para a estruturação de Núcleos de Inovação
Tecnológica é uma publicação do projeto InovaNIT
em parceria com o FORTEC e financiamento FINEP,
Resumo:
Book Chapter
1 - Nascimento da Eletrônica, 1907
Vitor Baranauskas
57
In: Fatos que mudaram nossa forma de ver o universo - Memória
Hoje -- Instituto Ciência Hoje(Ed.)
Instituto Ciência Hoje Rio de Janeiro, RJ v:2 Jul-2009 pp:192196
Na virada do século 19 para o século 20,
cientistas e engenheiros tentavam desenvolver um
equipamento que permitisse a recepção de ondas
eletromagnéticas capazes de transportar sinais de voz
As pesquisas foram impulsionadas pelo sucesso do
inventor italiano Guglielmo Marconi ao realizar, em
1901, a primeira transmissão telegráfica sem fio entre
o Canadá e a Inglaterra. Em 1907, o físico norteamericano Lee De Forest revolucionou os dispositivos
que eram construídos até então ao adicionar a uma
ampola de gás um terceiro eletrodo além do catodo e
do anodo. Após alguns aperfeiçoamentos, surgia a
válvula audion, responsável pelo desenvolvimento das
indústrias das transmissões radiofônicas, que mudaram
os hábitos em todo mundo.
Resumo:
Palavras-chave: Ciência-História, Literatura Científica,
Válvulas, Rádio, Telecomunicações.
A Institucionalização de Núcleos de Inovação
Tecnológica e a Experiência da Inova Unicamp
Roberto de Alencar Lotufo
In: Transferência de Tecnologia – Estratégias para a Estruturação
e Gestão de Núcleos de Inovação Tecnológica -- Marli Elizabeth
Ritter dos Santos, Patricia Magalhães de Toledo, Roberto de
Alencar Lotufo(Ed.) - ISBN: 978-85-7582-483
Editora Komedi Campinas-SP Jun-2009 pp:41-74
Palavras-chave: Inovação Tecnológica, Núcleo de
Inovação Tecnológica.
Alfabetização produz leitura orofacial? Evidência
transversal com ouvintes de 1ª a 3ª séries da
Educação Infantil, e de coorte (transversallongitudinal) com surdos de 4ª a 8ª séries do
Ensino Fundamental
Fernando Cesar Capovilla, José Mario De Martino, Elizeu
Coutinho de Macedo, Cibele Cecconi de Sousa e Sousa, Luiz
Eduardo Graton Santos, Karina Maki
In: Atualização em Transtornos de Aprendizagem -- José M.
Montiel ; Fernando C. Capovilla(Ed.) - ISBN: 978-85-36701080
Editora Artes Médicas São Paulo Mai-2009 pp:497-540
Resumo: Um teste computadorizado de avaliação da
habilidade de leitura orofacial foi aplicado a alunos
ouvintes da Educação Infantil (EI) e a alunos surdos
do Ensino Fundamental (EF), com o objetivo de
explorar, em surdos e ouvintes, a relação entre
alfabetização e leitura orofacial. Dois estudos foram
conduzidos: O Estudo 1 avaliou, em 27 alunos surdos
de 8ª. série do Ensino Fundamental (EF), a relação
entre leitura orofacial, leitura e escrita alfabéticas, e
compreensão de sinais da Libras. Esses alunos surdos
de 8ª. série do EF, foram avaliados nas versões
revisadas e computadorizadas de testes de
competência de leitura de palavras e pseudopalavras
(TCLPP-revis-comp), compreensão de leitura de
sentenças (TCLS-revis-comp), vocabulário de sinais
da Libras (TVRSLrevis- omp), habilidade de nomear
figuras por escolha de palavras (TNF-Escolha-revis-
58
comp v. 1 e 2) e por escrita à mão livre (TNF-Escritarevis-comp v. 1 e 2),e habilidade de nomear sinais da
Libras por escolha de palavras (TNS-Escolhareviscomp v. 1) e por escrita à mão livre (TNS-Escritarevis-comp v. 1 e 2). Esses mesmos 27 alunos surdos
também haviam sido avaliados nas mesmas
habilidades quatro anos antes, quando ainda estavam
na 4ª. série do EF. Resultados revelaram que, nas
crianças surdas, a habilidade de leitura orofacial está
fortemente correlacionada de modo positivo e
significativo com as seguintes habilidades ordenadas
de modo decrescente: 1) escrever nomes de figuras
(TNF-Escrita), 2) escolher nomes de figuras (TNFEscolha), 3) compreender sentenças escritas (TCLS),
4) escolher nomes de sinais (TNS-Escolha), 5)
escrever nomes de sinais (TNS-Escrita), e 6)
reconhecer e decodificar palavras e pseudopalavras
(TCLPP). Não houve qualquer correlação entre
habilidade de leitura orofacial e vocabulário em
Libras. Comparando os dados desses surdos nas
versões computadorizadas em 2008 com os dados
desses mesmos surdos coletados 4 anos antes nas
versões originais dos mesmos testes, foi descoberto
que as habilidades precursoras da leitura orofacial
(aquelas que, na 4ª. série, melhor predisseram a leitura
orofacial na 8ª. série) foram, em ordem decrescente, as
habilidades de: 1) escrever os nomes de figuras (TNFEscrita), 2) ler os nomes de figuras (TNF-Escolha), 3)
compreender sentenças escritas (TCLS), e 4)
reconhecer e decodificar itens escritos isolados
(TCLPP). Novamente, não houve correlação entre
habilidade de leitura orofacial e vocabulário em
Libras. O Estudo 2 avaliou, em 43 alunos ouvintes de
1ª., 2ª. e 3ª. séries da Educação Infantil (EI), a relação
entre: 1) a habilidade de leitura orofacial, avaliada por
meio da versão revisada e computadorizada da Forma
1A do Teste de Vocabulário em Português por Leitura
Orofacial (TVPlofrevis- comp), 2) a memória de
reconhecimento visual, avaliada por meio do Teste de
Memória de Reconhecimento de Figuras (TCMRF), e
3) a compreensão de palavras ouvidas, por meio do
Teste de Vocabulário por Figuras USP (TVFUsp92).
Resultados revelaram que as crianças ouvintes só
apresentam
habilidade
de
leitura
orofacial
significativamente acima do acaso a partir da 3ª. série
da EI, aos 6 anos de idade, quando estão sendo
alfabetizadas, e que o vocabulário receptivo visual em
Português por leitura orofacial se correlaciona de
modo positivo significativo com o vocabulário
receptivo auditivo em Português. Os dados dos dois
estudos sugerem que a habilidade de leitura orofacial é
promovida pela alfabetização, tanto em ouvintes
quanto em surdos, o que corrobora achados prévios
(Capovilla, Sousa-Sousa, et al., 2008) de que a
habilidade de leitura orofacial das palavras é
diretamente proporcional ao grau de frequência de
ocorrência das mesmas palavras escritas (i.e., à sua
familiaridade ortográfica).
Sinopse da FEEC
Palavras-chave: Leitura orofacial; Língua de Sinais
Brasileira; Educação para o portador de deficiência
auditiva.
Unicamp Campinas - SP Jun-2009
The objective of the meeting is to gather
mathematics professors, engineering professors,
mathematicians, engineers, specialists in mathematics
for engineering education and representatives from the
industry with strong emphasis in innovation
(Petrobras, Embraer, Whirlpool-Embraco, etc.) to
discuss new trends in the teaching of mathematics for
engineering students, with particular attention to the
situation created by an increasingly globalized
engineering practice.
Abstract:
What We Are Learning from Neurosciences about
Decision-Making: A Quest for Fuzzy Set
Technology
Armando Freitas da Rocha, Fernando Antonio Campos Gomide,
Witold Pedrycz
In: Views on Fuzzy Sets and Systems from Different Perpectives Philosophy and Logic, Criticisms and Applications -- Rudolf
Seising(Ed.) - ISBN: 9783540938019
Springer-Verlag Berlin May-2009 doi: 10.1007/978-3-540-938026_17
Abstract: Classic decision theory asserts that decision
makers should choose the option that offers the
highest expected value. Daniel Bernoulli [24] (Trepel,
Fox and Poldrack, 2005) suggested that people do not
evaluate options by their objective value but rather by
their utility and conjectured that appropriate choices
are those for which the expected utility is maximum.
Bernoulli also argued that utility functions should to
be a concave function because he assumed that the
marginal utility decreases as the assets increases.
Master's dissertations
Automation
HEURISTIC METHODS FOR OPTIMAL
ALLOCATION OF MAINTENANCE RESOURCES ON
ELECTRIC POWER DISTRIBUTION NETWORKS
Metodos heurísticas para Alocação Ótima de
Recursos de Manutenção para Redes de
Distribuição de Energia Elétrica.
Eduardo Tadeu Bacalhau
Supervisor: Christiano Lyra Filho (DENSIS)
Defense date: May,07 2009
This work is concerned with the optimal
allocation of maintenance resources on electric power
distribution networks. The mathematical model
represents the main components of the network, their
interrelationships for the operation of the network,
their reliabilities and the changes in condition due to
maintenance procedures. The objective of the
optimization process is the reduction of maintenance
costs under constraints of reliability, during a given
planning period. The best maintenance strategies can
be obtained from the solution of a mixed integer
combinatorial optimization problem, with continuous
and discrete variables. The main contribution of the
present work is the development hybrid heuristics that
are able to obtain better solutions for the problem,
with respect to previous approaches. Three hybrid
heuristics are developed, based on the depth first,
breath first and simulated annealing state space
searches. Case studies compare the three approaches
with a hybrid genetic algorithm previously proposed to
address the problem. The analysis of results highlights
the benefits of each approach
Abstract:
Channel Equalization Techniques for Wireless
Communications Systems
Cristiano M. Panazio, Aline Oliveira Neves, Renato da Rocha
Lopes, João Marcos Travassos Romano
In: Optimizing Wireless Communication Systems -- Francisco
Rodrigo Porto Cavalcanti, Sören Andersson(Ed.) - ISBN: 978-14419-0154-5
Springer New York-USA Jul-2009 pp:311-352 doi: 10.1007/978-14419-0155-2_8
Abstract: This chapter presents an overview of
techniques related to the problem of equalization for
wireless systems. The hereby desired recovery of
coded symbols transmitted through a propagation
channel is treated for the SISO scenario as well as for
the SIMO (beamforming) case. Techniques for
channel identification and tracking are discussed
together with means to handle time-dispersive
channels using either time- or frequency-domain
techniques. Furthermore, case studies exemplify
typical equalization solutions for wireless systems in
use today. Finally, the chapter discusses the concept of
– and principles for turbo-equalization, that is,
equalization structures that achieve near-optimal
performance by jointly performing equalization and
decoding.
Equalização linear, equalização com
realimentação de decisão, equalização turbo, beamforming,
equalização adaptativa.
Keywords: Reliability engineering, Electric Power,
Heuristic,
Optimization,
Simulated
annealing
(Mathematics)
Keywords:
Event Organization
Electrical Energy
TRAIN REGULATION FOR MASS TRANSIT
SYSTEMS
Regulação de trens em sistemas metroviários.
Wagner Schalch Mendes
Supervisor: Rafael Santos Mendes (DCA)
Trends in Mathematics for Engineering Education
Alberto Luiz Serpa, Jose Roberto de Franca Arruda, José Pissolato
Filho, Milton da Costa Lopes Filho, Sonia Maria Gomes, Philippe
Remy Bernard Devloo
The train regulation problem is of particular
importance among the scheduling problems found in
mass transit systems, being characterized by trains
running in urban regions taking passengers from one
Abstract:
59
location to another. If the desired headway between
trains, dwell-times in platforms and running times
between platforms are determined and known a-priori,
the steady state solution (timetable) can be calculated.
However, real systems are subject to disturbances such
as passengers preventing doors from closing,
mechanical or electrical failures, etc., that can deviate
the trains from the steady state. In this context, this
work is concerned with the determination of a control
law, i.e., a law for the determination of the arrival and
departure times of each train on each platform in the
system's cycles in order to reestablish and maintain the
timetable (reference solution). The proposed control
law is based on max-plus algebra concepts. The
desired arrival and departure times of each train on
each platform are calculated from the last occurrence
instants of the system's events and from a set of
matrices defined in max-plus algebra
Keywords: Feedback control system, Control theory, City
transportation, Subways
HEURISTICS FOR INTEGER PROGRAMMING WITH
FEASIBLE AND INFEASIBLE SEARCH
TRAJECTORIES
Heurísticas para programação inteira com
trajetórias de busca factíveis e infactíveis.
André Kazuo Takahata
Supervisor: Vinícius Amaral Armentano (DENSIS)
In this work we develop a set of generic
search
heuristics
for
solving combinatorial
optimization problems formulated as linear integer
programming models, using the XPRESS optimization
package. This is a recent theme, in which efforts have
been made in order to ;combine the flexibility offered
by heuristics and the expressive advances achieved in
the ;development of optimization solvers so as to
obtain high quality solutions in a short time. ;The
proposed heuristics are based on rounding solutions
located on the rays of a cone ;whose vertex is
associated with the optimal solution of the linear
programming relaxation, and in ;feasible and
infeasible trajectories relative to the frontier of such
relaxation. This approach is ;motivated by its
geometric appeal and by the success of similar
approaches in heuristics for ;solving combinatorial
problems. This work describes the development and
implementation of the ;heuristics and presents
computational tests on instances from literature.
Abstract:
Keywords: Integer programming, Heuristic, Combinatorial
optimization
CONSTRAINED CONTROL PROBLEM WITHIN A
FINITE HORIZON OF MARKOVIAN JUMP DISCRETE
LINEAR SYSTEMS
Controle em horizonte finito com restrições de
sistemas lineares discretos com saltos
markovianos.
Abstract: The purpose of this work is to propose and
solve the constrained control problem within a finite
horizon of Markovian Jump Discrete Linear Systems
(MJDLS) driven by noise. The constraints of the state
and control vectors are not rigid and limits are
established respectively to their first and second
moments. The controller is based on a linear state
feedback structure and shall minimize a quadratic cost
function. Two cases regarding the available
information of the Markovian chain states are
considered: firstly the Markov chain states are known
at each step and secondly only its initial probability
distribution is available. A deterministic formulation
to the stochastic problem is developped in order that
the proposed necessary optimality conditions and the
constraints are easily included by using Linear Matrix
Inequalities (LMI). The constraints consideration
constitutes the main contribution, since they are
pertinent to several application fields as for example
chemical industry, mass transportation, economy etc.
Two applications are presented for ilustration: one
refers to metro lines traffic regulation and another
refers to the financial investment income control
Keywords: Stochastic processes, Markov processes, Linear
systems
CONTROL VARIATION AS A SOURCE OF
UNCERTAINTY
Variação do Controle como Fonte de Incerteza.
André Du Pin Calmon
Supervisor: João Bosco Ribeiro do Val (DT)
This dissertation presents a theoretical
framework and the control strategy for discrete-time
stochastic systems for which the control variations
increase state uncertainty (CVIU systems). This type
of system model can be useful in many practical
situations, such as in monetary policy problems,
medicine and biology, and, in general, in problems for
which a complete dynamic model is too complex to be
feasible. The optimal control strategy for a
multidimensional CVIU system associated with a
convex cost functional is devised using dynamic
programming and tools from nonsmooth analysis.
Furthermore, this strategy points to a region in the
state space in which the optimal action is of no
variation (the region of no variation), as expected from
the cautionary nature of controlling underdetermined
systems. Numerical strategies for obtaining the
optimal policy in CVIU systems were developed, with
focus on the single-input input case evaluated through
a quadratic cost functional. These results are
illustrated through a numerical example in economics
Abstract:
Keywords: Stochastic control, Non-Linear systems,
Dynamic programming, Economic models, Convex
programming
Walter Furloni
60
Sinopse da FEEC
FORECAST OF SEASONAL STREAMFLOW SERIES
WITH ARTIFICIAL NEURAL NETWORKS AND
LINEAR MODELS ADJUSTED FOR BIO-INSPIRED
ALGORITHMS
Previsão de series de vazões com redes neurais
artificiais e modelos lineares ajustados por
algoritmos bio-inspirados
Abstract: For years, the human consciousness has
challenged scientists from several areas of knowledge.
In computer science, over the last decade, a significant
growth in the number of studies about artificial
consciousness has been observed. The architecture
Baars-Franklin, developed by Stan Franklin, is a
computational promising approach which is inspired
by the Bernard Baars' global workspace theory. This
work aims to discuss this technology and verify its
advantages and disadvantages. Due to the intrinsic
multidisciplinary characteristic of the study of
artificial consciousness, first of all, the main general
theories about consciousness are presented. After that,
the most relevant studies about artificial consciousness
are surveyed. Finally, the architecture Baars-Franklin
is applied to control a virtual creature in an
autonomous navigation problem. This dissertation
brings some theoretical contributions, aggregating
theories from other areas of knowledge, clarifying the
architecture Baars-Franklin and showing a practical
case study of the application of this model in order to
build an autonomous agent
Hugo Valadares Siqueira
Defense date: Jun,26 2009
The Electric System is one of the pillars of
technological and industrial development of a nation.
Thus, it is necessary to manage in an efficient manner
all necessary resources to obtain electrical energy.
Water resources become essential since the Brazilian
generator park is predominantly hydraulic. In this
context, the study of prediction of the streamflow
series of hydroelectric dams has become a field of
research highly relevant to the planning of energy
generation in Brazil. The models used by the electric
sector are called models of Box & Jenkins, which
requires pre-processing of input data due to the
seasonality found in streamflow throughout the year.
This work uses a range of forecasting models to
compare performance in the problem of monthly
averages streamflows series approached, in different
periods, the hydroelectric power plant of Furnas.
Among the linear models, it is proposed to use one of
a statistical model, the autoregressive and moving
average (ARMA), taking their coefficients calculated
by bio-inspired algorithms: genetic algorithm and two
proposed of immunological algorithms, one based on
small changes in CLONALG and opt-aiNet. Then, a
recurrent linear filter with the infinite impulse
response (IIR) has its coefficients calculated by the
optimization algorithms above. At the non-linear part,
it is the approach of applying artificial neural networks
of the type of multi-layer perceptron (MLP), using the
algorithm of the modified scaled conjugate gradient
for training. Finally, an echo states network is used in
the problem, with two training algorithms: the
proposal of Ozturk and of Consolaro. The
experimental results show the applicability of bioinspired tools and, in many cases, the importance of
the loop of feedback. For the non-linear case, it was
not possible to obtain significant results for the MLP,
while the ESN's have shown some promising results.
Abstract:
Keywords: Artificial intelligence, Cognitive science,
Intelligent agents (computer software), Simulation
(Computer), Consciousness
IMPULSE CONTROL WITH LIQUID LEVEL LIMITS
AND MINIMIZATION OF ACTUATIONS
Controle Impulsional para Limitação da Variação de
Nível com Minimização das Atuações.
Nathalie Carvalho Pinheiro
Defense date: Jul,30 2009
Time-series analysis, Neural networks
(Computer science), Evolutionary computation, Forecasting
hydrological
Keywords:
ANALYSIS OF BAARS-FRNKLIN ARCHITECTURE
OF ARTIFICIAL CONSCIOUSNESS APPLIED TO A
VIRTUAL CREATURE
Análise da Arquitetura Baars-Franklin de
Consciência Artificial Aplicada a uma Criatura
Virtual.
Ricardo Capitanio Martins Da Silva
Supervisor: Ricardo Ribeiro Gudwin (DCA)
Abstract: The high costs in offshore oil production are
reduced with the use of an innovative system which
has been developed by Petrobras, the Brazilian oil
company. Called VASPS (Vertical Annular Separation
and Pumping System), it consists of an undersea
gas/liquid separator. This work presents a strategy for
the liquid level adjustment in the VASPS tank, which
is subject to uncertain liquid inflow. This is far from a
strict control regulator problem, since the liquid level
may drifts freely inside an operation range. Although,
in one hand, it is necessary to account for a risky
operation near the limits, on the other hand, acting
freely and continuously in the controlled pump may
drastically shorten the lifetime of the equipment. To
prevent premature worn with halt in the oil production,
the control input variations should be meager. We
propose a stochastic impulse control for varying the
outflow pump speed. This formulation is transformed
in a sequence of iterated optimal stopping problems,
which results in a sequence of variational inequalities.
We employ the numerical method called Mean Value
Scheme (MVS) to solve this type of problem. This
monograph introduces impulse control to the resevoir
level adjustment of VASPS, together with the
application of the MVS to its solution
61
Keywords: Stochastic control theory, Stochastic partial
differential equations, Multiphae flow
ALGORITHM FOR SOLVING THE FUZZY
MULTICOMMODITY FLOW PROBLEM
Algoritmo para Resolução do Problema de Fluxo
Multiproduto Fuzzy.
Juliana Verga
Supervisor: Akebo Yamakami (DT)
Defense date: Aug,28 2009
The graph theory is commonly used in the
area of engineering to solve problems that can be
represented in the form of nets. Among several
problems, the multicommodity flow problem is one
that can be modeled by graphs. This work presents an
approach for solving the fuzzy multicommodity flow
problem. The problem was modeled through a graph
whose nodes represent points of supply and demand of
commodities, which pass through arcs of the network.
Our algorithm aims to find a set of good feasible
solutions for the fuzzy multicommodity flow problem
in networks with uncertainties in the costs and
capacities, containing multiple origins and multiple
destinations. The uncertainties are modeled by means
of the fuzzy sets theory, which has been successfully
applied to problems with uncertainties
Abstract:
Keywords: Graph theory, Fuzzy numbers, Fuzzy sets, Fuzzy
algorithms
Supervisor: José Antonio Siqueira Dias (DEMIC)
Although significant savings in electrical
energy are achieved with commercially available solar
water heaters, they do not present a good performance
in days that the radiation is not good, because the
boiler is filled with cold water whenever the hot water
is used. In this work, a new solar heating system,
which minimizes the use of electrical energy, is
proposed. The proposed system uses a fuzzy controller
that analyzes the intensity of solar radiation, the
temperature of the water inside the boiler and the
volume of water inside the boiler, to actuate on a
On/Off valve which controls the boiler's input of cold
water. Two solar heating systems were modeled: a
conventional system and the new proposed system
with the fuzzy controller; and their efficiencies were
compared using computer simulations. The obtained
results show that the proposed system with the fuzzy
controller presents a much higher performance when
compared to the traditional system. Simulation results
indicate that for a three winter days period, with low
intensity solar radiation, the conventional system
consumed 10.08 kwh of electrical energy while the
proposed system needed only 1.86 kwh to achieve the
same performance
Abstract:
Keywords: Fuzzy Logic, Solar water heaters, Solar
ROBUST STATIC OUTPUT FEEDBACK
CONTROLLERS FOR UNCERTAIN LINEAR
DISCRETE-TIME SYSTEMS
Realimentação de saida robusta a partir de
controladores dependentes de parametros para
sistemas lineares incertos discretos no tempo
Heber Rocha Moreira
Supervisor: Pedro Luís Dias Peres (DT)
This thesis deals with one of the most
important open problems in control theory, the design
of static output feedback controllers. The main
contribution is to propose a method to compute robust
static output feedback controllers for uncertain linear
discrete-time systems, using a state feedback
controller as an input parameter for the method.
Additionally, the results are extended to cope with H2
static output feedback control design. The synthesis
conditions are formulated in terms of a convex
optimization procedure, based on a finite set of linear
matrix inequalities. Numerical examples are presented
to illustrate the effectiveness of the proposed approach
compared to other methods available in the literature.
Abstract:
Keywords: uncertain linear discrete-time systems, control
theory
Heating, Solar collectors
POINT OF SALES OF ELECTRICAL ENERGY USING
PRE-PAID INDUCTIVE CARD
Ponto de venda de energia elétrica com cartão
indutivo pré-pago.
Paulo Henrique De Oliveira Lopes
The increasing in pollution caused by
combustion engines in large cities has motivated the
search for new technologies to replace these engines,
and the electrical vehicle is a promissing alternative in
the near future. However, one of the problems that
remains to be solved is charging these vehicles in the
streets. This works presents the design, development
and implementation of a pre-paid point of ;sale of
electrical energy equipment which uses inductive
cards. The developed prototype meets the
specifications and rules of the Brazilian electrical
sector for the energy meters. Other applications for
this pre-paid energy meter are being considered, as,
for example, in selling pre-paid energy to low.
Abstract:
Keywords: Electric meters, Electric vehicles, Watt-hour
meter
FYZZY CONTROLLER FOR OPTIMIZATION OF
WATER HEATING SYSTEMS WITH SOLAR
COLLECTORS
Controlador fuzzy para otimização de sistemas de
aquecimento de água com coletores solares.
FIELD EFFECT TRANSISTORS (FET) WITH
DIELECTRIC GATE MADE OF A STACKED LAYER
SINX/SIOXNY FOR CHEMICAL AND BIOCHEMICAL
DETECTION
Transistor de Efeito de Campo (FET) para Detecção
Química e Bioquímica Utilizando Dielétrico de Porta
Constituído de Camada Empilhada SiNx/SiOxNy.
Marcela Ormenese
Jair Fernandes de Souza
62
Sinopse da FEEC
Supervisor: Peter Jürgen Tatsch (DSIF)
This dissertation consists of two stages.
Initially are studied Silicon Nitride films deposited by
LPCVD (Low Pressure Chemical Vapor Deposition)
using different relationship of reagent gases
concentration ([SiH2Cl2] / [NH3]) and using as
substratum Silicon wafers p-type with and without pad
layer of Silicon Oxinitride - SiNx/Si and
SiNx/SiOxNy /Si structures. The films were
characterized physically and electrically as well as the
point of view of adsorption capacity of biologically
active monolayer. The films characteristics were
compared, seeking to identify a film whose
characteristics are adequate to be used as dielectric
material applied at the project and fabrication of
chemically and biochemically sensitive Field Effect
Transistors - FETs. Ellipsometry results pointed films
with refraction indexes ranging from 1,875 to 1,990, it
indicating films rich in Nitrogen, and with thickness
directly proportional to the relationship of reagent
gases concentration. In the other words, the increase of
the relationship of gases concentration produces an
increase of the films deposition rates. The infra-red
absorption spectroscopy allowed us to analyze the
chemical bonds present in the dielectric films and in
the self assembled monolayers formed by the
immobilization of biological molecules. The films
spectrum have absorption spike in 827/837 cm-I and
451/484 cm-I that correspond to Si-N bonds,
confirming the indication of the ellipsometry
regarding as nitrogen presence. After self assembled
monolayers formation composed by proteins of the
type Immunoglobulin - IgG 2.5 and 5%, the spectra
showed absorption bands of IR, around 3300 cm-1 and
in the ranges of 1700 to 1600 cm-1 and 1600 to 1500
cm-1, spectrum that characterizes the formation of
amida groups A, I and II, respectively, in other words,
the formation of biologically active monolayers.
Through micro-Raman spectrometry were detected
displacements in the main spikes of the Silicon
substratum. This displacement has been related with
the stress induced by the deposited films. It was
manufactured Metal Insulating Semiconductor (MIS)
capacitors,
using
the
structures
dielectric/semiconductor obtained. The capacitors
made possible to accomplish the electric
characterization of the films through high frequency (1
MHz) capacitance-voltage (C-V) measurements,
obtained the density of charges existent on the
interface dielectric/semiconductor - around 1011 cm2; and to observe the behavior of the interface with the
accomplishment of thermal stages and the degradation
in its recombination properties. After production and
characterization of the dielectric layers, has been
accomplished the second stage of the work with the
production of FETs, being used as dielectric gate the
films that presented better performance of the point of
view physical, electric, chemical and biological. The
electric characterization of the FETs that compose the
arrays, has been accomplished being used the control
devices disposed separately in the dies allowing to
raise the characteristics of the devices construction, as
well as, the behavior of the same ones when submitted
to thermal stages. The chemical sensibility was
verified being applied analytes with different H+ ions
concentrations - different pH values - in the gate area
of the FETs that compose the arrays. The viability of
use of the modified FETs for chemistry/biochemistry
detection was demonstrated, with employment
possibility in activities of medical diagnosis,
environmental control, control of the production of
drugs and cosmetics and agricultural applications
Abstract:
Keywords: Silicon mitride, Field-effect transistor, Silicium,
Chemical vapor deposition
DATA ACQUISITION SYSTEM GEOREFERENCITY
FOR ELETRICS MOTORCYCLES
CHARACTERIZATION
Sistema Georeferenciado de Aquisição de Dados
para Caracterização de Motos Elétricas.
Nestor Ezequiel De Oliveira
Supervisor: Elnatan Chagas Ferreira (DEMIC)
Approximately 40% of the total energy
produced in the world is consumed in the transport
sector, having created a great demand for studies of
alternative sources of energy for the vehicles. This
academic work has as for objective to present a study
developed with electric motorcycles (VEs), with the
development of project of electronic circuits of
acquisition of data and conditioning of signs of the
electric and mechanical greatness, such as tension of
the battery, consumed electric current, load of the
battery, temperature, RPM of the motor, speed of the
electric moto, and everybody the data are
georeferencing. These data supply important
information on the characteristics and the acting of the
studied electric motorcycles, besides revealing
information that can demonstrate the viability of using
this vehicle in commercial applications. The results
obtained with the monitoration of these (VEs) for 12
months are presented
Abstract:
Keywords: Electric vehicles, Motorcycle, Data aquisition,
Remote sensing, Electric batteries
PCB-MEMS : TECHNOLOGY AND PHYSICAL
IMPLEMENTATION OF MICRO SWITCHES ON
PRINTED CIRCUIT BOARD FOR RF AND
MICROWAVE APPLICATION
MEMS-PCB: Tecnologia e Implementação Física de
Micro-Chaves em Placa de Circuito Impresso para
Aplicação em RF e Micro-Ondas
Mauricio Weber Benjo Da Silva
Supervisor: Luiz Carlos Kretly (DMO)
Abstract: The development of RF MEMS (Micro
Electro Mechanical System) switches, using the
concepts and technology of Printed Circuited Board
63
(PCB) is the object of this research. Micro switches in
the shunt configuration through the Coplanar
Waveguide (CPW) were manufactured. Recently, its
applications have been directed to more sophisticated
circuits, which are monolithic integrated with other RF
components such as antennas and phase shifters. The
developed switches are designed to operate with low
actuation voltage and manufactured using the surface
micromachining technique, which consists to build the
structures in thin film layers, and removing the
sacrificial layers to the release of the flexible device
part. In this work is presented all the methodology of
the project, including the electromechanical and
electromagnetic simulations of the MEMS switches on
PCB, as well as the characterizations. The switches
had shown compatible performance when compared
with equivalent RF devices available in the market,
showing broadband operation from 1,8 - 18 GHz. Due
the physical and operational performance of the
manufactured devices, this technology shows viable
with locally known technologies and feasible for
applications in both Radio Frequency and microwave
Keywords: Micro-Electrical-Mechanical-Systems (MEMS),
Printed circuit, Radio frequency, Microwave, Fabrication
process
REFERENCE VOLTAGE AND TEMPERATURE
SENSING SIGNAL GENERATION USING MOS
TRANSISTORS IN STRONG INVERSION
Geração de Tensão de Referência e Sinal de
Sensoriamento Térmico Usando Transistores MOS
em Forte Inversão
Ricardo Pureza Coimbra
Supervisor: Carlos Alberto dos Reis Filho
(DSIF/FEEC/UNICMAP)
Voltage references and temperature sensors
are blocks extensively used in microelectronic
systems. As an alternative to the use of consolidated
structures that are protected by intellectual property
agreements, there is a permanent demand for the
development of new techniques and structures for
these circuits. It can be also highlighted the growing
interest for low-voltage and low-power solutions,
implemented in conventional IC technologies. This
work describes the development of a circuit that meets
these requirements by providing a voltage reference
and temperature sensing signal obtained from a
suitable arrangement of MOS transistors biased in
strong inversion. The operation principle of the circuit
developed is based on the concept that it is possible
for a stack of n MOS transistors, biased by an
appropriate current, to show a voltage drop, equal to
nVGS, with the same thermal variation rate as a VGS
voltage produced by a single transistor. Hence, the
difference between the two voltage signals is
temperature independent, characterizing a voltage
reference. However, the stacking of two or more
transistors prevents the operation of the circuit under
Abstract:
64
low voltage. This fact motivated to adapt the technique
by obtaining the voltage nVGS with the aid of an array
of resistors and no stacked transistors. The minimum
supply voltage becomes limited only by the reference
voltage itself, whose amplitude is close to a single
VGS. The circuit developed also provides a voltage
signal almost linearly dependent with the absolute
temperature, which can be applied for thermal sensing.
Prototypes corresponding to various dimensional
versions of the circuit were produced to
experimentally verify the principle of operation. The
best performance corresponds to the generation of a
voltage reference signal with 8.7ppm/ºC thermal
coefficient, from -40ºC to 120ºC, under a 1V supply
voltage. Although the state of the art is represented by
values as low as 1ppm/ºC, at the same temperature
range, the circuit's compact aspect together with the
possibility to attend low-voltage and low-power
requirements grants it value as contribution to this
field of research and development.
Keywords: Metal oxide semiconductors, Analog integrated
circuits, Integrated circuits, Semiconductors, Analog
electronic systems
STUDY AND COMPENSATION OF BIAS DRIFT,
SCALE FACTOR STABILITY AND LINEARITY OF A
CONDITIONING AND SIGN PROCESSING CIRCUIT
OF AN INTERFEROMETRIC FIBER OPTIC
GYROSCOPE
Estudo e compensação da deriva térmica,
estabilidade do ganho e linearização de um circuito
de condicionamento de sinais de girômetro
interferométrico a fibra óptica.
Rodrigo Horikawa Watanabe
Supervisor: Elnatan Chagas Ferreira (DEMIC)
Abstract: Fiber Optic gyroscopes are an important part
of inertial navigation systems. To meet the necessary
specifications required for application in inertial
systems, it is mandatory that the electronic Sagnac
demodulator uses state of the art devices. The proposal
of this work is to study and develop a technique to
correct all together for the nonlinearities, the bias drift
and scale factor stability, found in gyroscope
electronic circuits, in order to improve the gyroscope
performance. An optical circuit emulator, was
developed using a software written in LabVIEW. The
software controls an arbitrary wave generator and
calculate the optical circuit output signal using a
theoretical formulation. The results of the emulated
signal are compared with theoretical values of a
Sagnac interferometer and presents only §0; 02%
difference error. It was developed a new calibration
system that uses look-up-table technique to
compensate for the thermal drift and correct the circuit
non-linearities. This correction technique improves
bias drift from 0; 15±=h to 0; 065±=h, for the
temperature range 35±C to 75±C; scale factor stability
Sinopse da FEEC
athlete and allows the training monitoring, with a
maximum transmission range of 70 m, with very
satisfactory data acquisition results, although small
size (37x49x20 mm) and lightweight (40 g). Making it
a versatile alternative to aid athletes and coaches
during the training, allowing technique refinement.
This system is also a suitable tool for physical
education research area
from §1000ppm to §175ppm, for the temperature
range 35±C to 75±C and linearity from 3% to 0; 03%
Keywords: Giroscopios, Optical gyroscopes, Calibration
Arquitetura e Implementação de uma Rede em Anel
de Comutação Óptica de Pacotes.
Vinícius Garcia de Oliveira
Abstract: A convergência das aplicações dos serviços, das mídias
e das redes especializadas para a Internet está mudando o mundo e
o jeito como as pessoas agem e interagem. Embora com
limitações, computação distribuída, teleconferência, tele-educação,
radio, televisão e jogos já são possíveis na Internet. Num futuro
próximo estas limitações desaparecerão, e será possível suportar
aplicações bem mais sofisticadas e complexas, tais como realidade
virtual colaborativa, tele-presença, tele-cirurgia, e muitas outras.
Para que este futuro se torne realidade é necessário que as
arquiteturas das redes de telecomunicações evoluam para um novo
paradigma de rede que abranja todas as camadas de transporte, de
serviço e de gerência.
Assim, este trabalho visa apresentar uma nova arquitetura de rede
de chaveamento de óptico de pacotes que objetiva atender as novas
demandas de tráfego associando ao conceito de chaveamento de
pacotes técnicas de montagem de rajadas e alocação de
comprimentos de onda. Também são apresentados neste os
resultados de simulações e, ao final, o projeto de implementação e
prototipagem da rede.
Keywords: controle de acesso ao meio., pacotes ópticos, redes
reconfiguráveis, transmissão de rajadas,arquitetura de redes
Keywords: Accelerometer, Gyroscope, Remote sensing,
Instrumentation, Wireless communication systems
SPECIFICATION OF A DATA PROCESSING CORE
FOR AN OPTICAL BURST SWITCHING NETWORK
Especificação do Núcleo de Processamento Para
Rede de Chaveamento de Rajadas Ópticas.
Luis Renato Monte
This work presents the architectural and
functional specifications of a new optical network,
based on optical burst switching that aims at the better
use of optical links and the reduction of the bottleneck
resulting from electro-optics conversions. A proposed
design of the core data-processing based on
programmable logic devices and design of circuits
used in the experimental stage, which include a
business board and three boards developed exclusively
for this project, will be presented. This work aims to
present a new architecture for an optical burst
switching network, its basic operation and the
structure of an optical switching node. The data
processing core structure is proposed and the circuitry
prototypes developed to do the proof of concept are
presented
Abstract:
MICROCONTROLLER SPORT ACTIVITIS
MONITORING SYSTEM PROTOTYPE BASED ON
ACCELERATION AND ROTATION
MICROELECTROMECHANICAL SENSORS
Desenvolvimento de um Sistema Microcontrolado
para Monitoramento de Atividades Esportivas
Baseado em Sensores Microeletromecânicos de
Aceleração e Giro.
Keywords: Optical fibers, Optical communications, Optical
Yull Heilordt Henao Roa
Supervisor: Fabiano Fruett (DSIF)
Abstract: Although there are several technological
tools to aid the training in sports, most of them are
high cost solutions and generally very specific to a
particular sport, which hinders the diffusion of such
technologies. This paper proposes the development of
a low cost non-invasive microcontroller Sport
ActivitiesMonitoring System (SAMS) prototype,
based
on
acceleration
and
rotation
microelectromechanical sensors (MEMs) for obtaining
biomechanical data during training in athletes, without
leave the natural environment of their activities. The
sensors signals are wireless transmitted from the
SAMS to the computer in order to process the data, by
an easy and intuitive program interface developed in
LabVIEWr. This software saves and displays real time
data information in a graphic form. The field tests
were made by stationary bike in the laboratory of
Instrumentation for Biomechanics, at the Faculty of
Physical Education in the Campinas University
(UNICAMP) in Brazil, and in a cycle track in
Americana city. This prototype is easy to attach to the
switching, FPGA
Biomedical Engineering
IMAGE QUALITY EVALUATION SYSTEM FOR
DENTAL DIGITAL RADIOLOGY
Sistema de Avaliação de Qualidade de Imagem em
Radiologia Digital Odontológica.
Tiago Freire Carneiro Leão
Supervisor: Eduardo Tavares Costa (DEB)
Abstract: New systems and technologies for radiation
detection intended for dental radiology have become
available as an alternative to dental radiographic film.
Systems based on PSPL technology seems to
overcome some of the restrictions of systems based on
CCD technology such as the bulky detector,
connecting wire, limited image size and limited
exposure latitude. It is important that competing
imaging systems can be compared (different
technologies or different manufacturers of the same
technology) by means of quality control tools and
quality certification protocols. A software package and
a set of specific phantoms were developed and the
analyses of two competing PSPL systems were
conducted to validate the developed system. The
65
software allows the user to obtain and analyze: the
characteristic curve, modulation transfer function
(MTF), noise power spectrum (NPS), noise equivalent
quanta (NEQ) and detective quantum efficiency
(DQE). The results have shown that the developed
software and phantom set allow quality control of
digital dental radiology systems in a very objective
and quantitative way, facilitating comparative analysis
of competing commercial systems. Keywords: Digital
dental radiology, quality assurance in radiodiagnostic,
characteristic curve, detective quantum efficiency,
modulation transfer function, noise power spectrum,
noise equivalent quanta
Dental radiology, Radiology,
diagnostic, Optical transfer, Quality control
Keywords:
Imaging
DEVELOPMENT OF AN INCIDENT INVESTIGATION
GUIDE FOR HEALTHCARE ENVIRONMENTS
BASED ON THE PROJECT MANAGEMENT
STRUCTURE
Desenvolvimento de um Guia para Investigação de
Incidentes em Ambientes de Saúde Baseado na
Estrutura de Gerenciamento de Projetos.
Plinio Pelegrini Morita
Supervisor: Saide Jorge Calil (DEB)
The hazards inside a healthcare institution
are increased by the growth in the use of more
technological
equipments.
Consequently,
risk
management measures must be taken to ensure both a
safe workplace and an improved safety for the
patients, family and visitors that transit daily by these
institutions. One possible risk management measure is
the incident investigation, in which information from
occurrences are gathered and analyzed to generate
possible procedural and structural modifications in the
institution, therefore reducing the probability of future
occurrences. The development of the methodology
presented in this work was based on techniques widely
spread in several industry sectors that already have
highly
developed
incident
investigation
methodologies. This work proposes a complete
incident investigation methodology for the
investigation of any type of incident in a healthcare
institution, as well as the necessary support for the
development of a safety culture that, through time,
increases the safety of the patients and the quality of
the service offered by these institutions. It also has the
objective of filling an existing gap in healthcare
institutions risk management programs, since the
available incident investigation methodologies are not
specific to investigations in healthcare institutions nor
cover adequately all the activities inside the incident
investigation process. Consequently, it's not possible
to investigate all types of occurrences in healthcare
institutions. The investigative process here presented
is structured according to the project management
theory in which the necessary activities were divided
into two big blocks: one for initial foundation and one
Abstract:
66
consisting of four phases for the investigation process.
In the Initial Foundation block are presented and
discussed all the necessary requirements in a
healthcare institution for the implementation of an
incident investigation system, varying from the team
to be used to investigate to the institution's culture. In
the Investigative Process block, the Phase 1 Investigation Initialization describes the activities to
be performed between the occurrence notification and
the arrival of the team at the incident site. In the Phase
2 - Evidence Collection are described the activities
that the investigation team will conduct while in the
scene and prior to the evidence analysis. In the Phase 3
- Evidence Analysis are discussed the analyses
processes and procedures to be undertaken on the
collected evidences so that it becomes possible to
determine the involved scenarios and the root causes
of such scenarios. In the Phase 4 - Recommendations
and Report, instructions are presented regarding the
development of recommendations that are adequate to
the characteristics of the institution and how to present
them in order to achieve the best results. This division
has the objective of making this methodology easier to
be followed and to divide the arduous investigation
process into smaller sub-activities. This work resulted
in a clear, complete and easy-to-use guide that allows
the investigation of any type of incident, providing
another helpful tool for the healthcare institutions risk
management system
Keywords: Accidents, Hospitals, Risk management, Project
management
ULTRASOUND CERAMIC TRANSDUCER ARRAYS :
CONTROL, TRANSMISSION AND RECEPTION
CIRCUITS
Acionamento de Elementos Cerâmicos de
Transdutores de Ultra-Som: Circuitos de Controle,
de Transmissão e de Recepção.
João Loures Salinet Júnior
Supervisor: Eduardo Tavares Costa (DEB)
Ultrasound image equipments associate
different techniques to provide not only anatomical but
also functional information of body parts and organs
in real time and with excellent image quality. This is
due to great advances in transducer technology and
also to digital and analog electronics with the use of
microcomputers, digital signal processors (DSPs) and
field programmable gate arrays (FPGAs) even faster
and powerful, allied to new digital signal and image
processing techniques. The objective of the present
work was the development and construction of circuits
to actuate on piezoelectric ceramic transducer arrays.
The circuits are able to generate and receive
ultrasound waves and were developed with techniques
for high frequency multilayer printed circuit boards. In
order to reduce hardware size it was used surface
mounted devices (SMD). The system consists of a
control circuit, a interconnection board, power supply
Abstract:
Sinopse da FEEC
(10 different voltage), two four channel printed circuit
boards with the transmission and reception circuits to
be used with transducer arrays. It was used VHDL for
hardware description language and the control circuit
defines pulse width, repetition rate and temporal
phasing for activation of each element of the
transducer array enabling focusing and ultrasound
beam in different directions. The transmission circuits
generate pulses up to +65V that are triggered by the
control circuit (20 ns minimum pulse width). The
protection circuit is very efficient avoiding high
tension electrical surges. The reception circuits have
mixed technologies (analog and digital integrated
circuits) with 100 MHz bandwidth, low noise and up
to 70 dB gain. This gain can be programmed through 3
independent amplification stages (LNA, VCA and
PGA). The system has been tested in laboratory and
presented adequate performance, being versatile and
allowing its use with array transducers becoming an
interesting tool for education and research purposes
Moreover, the effective dose of each procedure for
each professional was calculated and data analysis of
the thermoluminescent dosimeters used in the whole
Laboratory working periods was made. In conclusion,
the dose reduction caused by pulsed technology was
not significant, and new strategies to reduce
occupational doses in the Catheterism Laboratory are
proposed
Keywords: Cardiac catheterim, Fluoroscopy, X-rays,
Radiation
A NEW FLUID FLOW SENSOR FOCUSED ON THE
BIOMEDICAL APPLICATION
Novo sensor de vazão de fluídos com foco em
aplicações biomédicas.
André De Paula Ramos
Supervisor: Antônio Augusto Fasolo Quevedo (DEB)
Keywords: Ultrasond, Ultrasonic transducers, Electronic
circuits
OCCUPATIONAL DOSE STUDY IN THE CARDIC
CATHETERISM LABORATORY OF UNICAMP'S HC :
PULSED FLUOROSCOPY VERSUS CONTINOUS
FLUOROSCOPY
Estudo da Dose Ocupacional no Laboratório de
Cateterismo Cardíaco do HC da UNICAMP:
Fluoroscopia Pulsada Versus Fluoroscopia
Contínua.
Mariana Sacrini Ayres Ferraz
Supervisor: Sérgio Santos Muhlen (DEB)
Abstract: Procedures of catheterism using fluoroscopy,
as coronary angioplasty, are responsible for high doses
of radiation (higher than conventional radiology), not
only for patients but for the medical staff as well. The
intensive use of X-rays increases radiological risks, as
a consequence of cumulative exposition, for
cardiologists and their teams. The main risks resulted
from high doses of X-rays are: cancer, cataracts,
malformations, and damage to the fetuses of pregnant
women. The production of X-rays with pulsed
technology, which is now available in many hospitals,
implies a potential reduction of the radiation dose
received by the medical staff. The amount of dose
reduction is still controversy in literature, but some
authors report reductions up to 70%. This work aimed
at study occupational dose in the Cardiac Catheterism
Laboratory of UNICAMP. The doses received by the
medical staff on the continuous and pulsed
fluoroscopy modes were compared, and the dose
reduction consequent to the change of technologies in
the Laboratory (from continuous to pulsed
fluoroscopy) was measured. The reductions found for
main and auxiliary physicians were 5.2% and 13.7%,
respectively. For nurses, auxiliary nurses and
technicians, the reductions were 7.5% to 8.2%.
Spirometer is a device that evaluates
pulmonary ventilation. This paper presents a
preliminary study of a new electromechanical sensor,
focused on the biomedical application of spirometry.
The sensor is composed of a bluff body positioned
inside a tube trough a hole, being a part of the body
inside and another part outside of the tube, and an
accelerometer positioned on the outside part. Within a
fluid flow, the bluff body causes vortex shedding, and
the vortexes induce vibrations on the body. Also, the
viscous force of the flow drags the bluff body. Both
movements are captured by the accelerometer and
correlated with the flow. One important feature of this
sensor is that the fluid does not contact any of the
electronics, easing tube lumen sterilization procedures.
Three types of bluff bodies were studied: two blades
(with and without additional mass), and one cylinder.
The experimental procedure consisted of establishing
six different air flows and then capturing the
accelerometer response in all of its three axes. Each of
the collected signals from the accelerometer was
divided in 24 parts, and these parts where analyzed
through statistics; finally the mean response of the
sensor was plotted. Best results were found in the
accelerometer axis parallel to the air flow. In the blade
tests, the RMS value of the AC component was
proportional to the air flow, with linearity and
correlation varying, respectively, from 19% and R2 =
0.99058 for the blade without mass, to 8.4% and R2 =
0.9741 for the blade with additional mass. It was
observed that the mass addition reduced in a
meaningful way the response variances. Yet the
viscous force (DC value) did not respond in a
monotonic way with the increase of air flow. On the
other hand, the viscous force was the most expressive
regarding the experiments with the cylinder (linearity
of 0.17% and R2 = 0.96347), but the RMS value did
not respond in a monotonic way. Finally, although
further studies are needed to prove that the proposed
sensor is efficient to be used in spirometry equipment,
this study demonstrates that this sensor responds
Abstract:
67
proportionally to the flow input, within (0 to 14 l/s)
and without (up to 21 l/s) the spirometer operation
range, with high correlation and linearity, as well as
varying responses, given different inputs (flow), as
verified by ANOVA test (p < 10-15).
Keywords: Vortex Sensor, Accelerometer, Drag
(Aerodynamics), Spirometer, Resonant Vibration
SPEECH SYNCHRONIZED 2D FACIAL ANIMATION
BASED ON PHONETIC CONTEXT DEPENDENT
VISEMES IMAGES
Animação Facial 2D Sincronizada com a Fala
Baseada em Imagens de Visemas Dependentes de
Contexto Fonético
Paula Dornhofer Paro Costa
Supervisor: José Mario De Martino (DCA)
Abstract: Speech synchronized facial animation allows
the implementation of talking heads that potentially
can improve human-computer interfaces making them
more efficient and attractive. This work presentsan
image based 2D facial animation synthesis method
whose development was guided by two main goals:
the realistic reproduction of visible speech articulatory
movements, including coarticulation effects, and the
possibility to implement the method also on limited
processing and memory platforms, like mobile phones
or personal digital assistants. The developed method is
based on an image database of Brazilian Portuguese
context dependent visemes and uses the morphing
between visemes strategy as facial animation synthesis
technique. The proposed approach represents an
alternative and innovative synthesis strategy, capable
of reproducing the visible speech articulatory
movements, including coarticulation effects, from an
image database of just 34 images. This work includes
the implementation of a pilot system integrated to a
text-to-speech synthesizer. Additionally, the proposed
synthesis method is evaluated through a speech
intelligibility test. The test results indicate that the
animations generated by the system contribute to
improve speech intelligibility when audio is degraded
by noise. Despite the fact this work is restricted to
Brazilian Portuguese, the presented solution is
applicable to other languages. Keywords: Computer
Graphics, Facial Animation, Visemes, Coarticulation,
Morphing
Keywords: Computer graphics, Animation, Morphing,
Computer animation, Visual communication
A TOOL TO SUPPORT DOCUMENTATION AND
TRACEABILITY OF INFORMATION ELEMENTS IN A
SOFTWARE TESTING PROCESS
Uma ferramenta para suporte à documentação e
rastreabilidade da informação de um processo de
teste de software.
Software plays a key role in many
applications and quality of software products is crucial
in the competitivity of software development
companies, which are increasingly putting effort in the
quest for good quality in their products. In this
context, testing is recognized as a key process to
achieve this goal; however, systematic software testing
is not an easy activity. For testing to have
effectiveness and efficacy, in addition to product
evaluation aspects, it must make use of good quality
documentation: all the recorded information must be
up to date and consistent; also, associated information
must be traceable. A traceability model is proposed for
the information contained in the documentation of the
testing process; the data model developed gives
support to documentation based on the standard IEEE
Std 829-1998, as well as to traceability of all
associated information; a prototype tool was
developed to implement the data model and the
traceability model
Abstract:
Keywords: Software, Documentation, Traceability
INFRASTRUCTURE SERVICES PLATFORM FOR
MOBILITY ARCHITECTURES
Plataforma de Serviços de Infra-estrutura para
Arquiteturas de Mobilidade.
Tiago Marchetti Dolphine
Supervisor: Eleri Cardozo (DCA)
Micro-mobility architectures have been
proposed to meet the growing interest in technologies
supporting mobility in IP networks. MPA (Mobility
Plane Architecture), developed at the FEEC/Unicamp,
is a micro-mobility solution based on tunneling of
packets that employs only well standardized protocols.
When applications for supporting seamless handover
and traffic engineering in MPA started to be designed,
it was noticed that these applications demand a set of
common services. This dissertation presents the MIS
(Mobility Infrastructure Services) platform which
provides a set of services that meet the common basic
features demanded by applications of network
management, traffic engineering and mobility
management. The proposed platform facilitates the
development of these applications when they are
targeted to MPA and other micro-mobility
architectures. This dissertation reports the design,
implementation, ant test of the MIS platform, along
with two case studies in mobility management and
traffic engineering. Keywords: IP mobile networks,
micro-mobility,
network
management,
traffic
engineering
Abstract:
Computer network protocols, TCP/IP
(Computer network protocol), Telecommunications traffic,
Internet (Computer network), Wireless communication
systems
Keywords:
Jorge Luiz Da Cruz
Supervisor: Mario Jino (DCA)
68
Sinopse da FEEC
is addressed to the problem of salient poles and
cylincrical rotor synchronous generator parameters
determination aided by the use of dynamic simulations
implemented with the Matlab/Simulink package using
its SimPowerSystems library. Some results and
conclusions about the parameters determination are
presented using the standardized and fundamental
parameters as shown in the Krause book published in
1986. This paper has both didactic and technological
subjects and it is addressed to discuss several aspects
on the real parameters determination activities
Electrical Energy
CALCULATION OF PARAMETERS OF THRESSPHASE TRANSMISSION LINES THROUGH
VOLTAGES AND CURRENTS IN THEIR TERMINALS
Cálculo dos Parâmetros de Linhas de Transmissão
Trifásicas Através das Tensões e Correntes em
seus Terminais.
Leonardo Silva Lustosa
Supervisor: José Pissolato Filho (DSCE)
Abstract: The objective of this work is to calculate the
longitudinal and transversal transmission line
parameters using phase currents and voltages.
Developed equations are used, in the modal domain,
considering current and voltages found between a line
terminal and an open line terminal, and a short-circuit
terminal. . Initially, the basic transmission line theory
is presented assuming that these lines are best
represented by distributed parameters model.
Therefore, through the analysis of electric circuits and
Kirchhoff's laws, second order differential equations
for voltage and current are found, which characterizes
the line transmission. Next it is shown the method to
calculate the line parameters, which uses the concept
of open circuit and short-circuit equivalent impedance
when one of the terminals is open or in short-circuited
respectively. Using the Toolbox of MatLab,
SimPowerSystem, estimated currents are simulated in
a three-phase transmission line of 330 kV, 440 kV and
500 kV, all with the length of 500 km. The found
values are used to calculate parameters of lines
transmission and to compared them with their real
values, showing that the calculation is possible and
that the error obtained with this method is smaller than
an error between the real line parameters after
construction and those of existing project in the data
base of companies
Overhead electric lines, Electric power
transmission, Modal analysis, Electric networks
Keywords:
machinery,
production
A LINEAR MAXIMUM TORQUE CONTROL OF THE
INTERIOR PERMANENT MAGNET SYNCHRONOUS
MOTOR
Controle Linear de Máximo Torque do Motor
Síncrono de Ímãs Permanestes Interiores.
Daniel De Figueiredo Maria
Supervisor: Edson Bom (DSCE)
Abstract: In
this work is presented the linear maximum
torque control of an interior permanent magnet
synchronous operating in the constant torque and field
weakening ranges. The constant torque control is
implemented by using the maximum torque per
Ampére curve of the motor. The terminal stator
voltage remains constant along the field weakening
range due to the armature reaction control. In order to
obtain a better dynamic response, the maximum torque
per Ampére control is extended up to the field
weakening range, in an intermediate region, called
partial field weakening region. Experimental and
simulation results are presented in order to validate the
proposed torque control methods
Keywords: Synchronous motors, Vector control, Permanent
magnets
Keywords:
ON THE DETERMINATION OF PARAMETERS
SYNCHRONOUS GENERATORS FOR THE STUDY
OF DYNAMIC BEHAVIOR OF POWER SYSTEMS
Sobre a Determinação de Parâmetros de Geradores
Síncronos para Estudos de Comportamento
Dinâmico de Sistemas Elétricos.
Juan Carlos Peqquena Suni
Supervisor: Ernesto Ruppert Filho (DSCE)
Electric machinery synchronous, Electric
Transients (Electricity), Electric power
METHOD BASED ON FUZZY LOGIC FOR
ALLOCATING DISTRIBUTED GENERATORS FROM
THE VIEWPOINT OF THE VOLTAGE PROFILE
Método Baseado em Lógica Nebulosa para
Alocação de Geradores Distribuídos Sob a Óptica
do Perfil de Tensão.
Leonardo Alonso Gomes
Supervisor: Carlos Alberto Favarin Murari (DSEE)
The synchronous generator dynamic
mathematical model parameters like the per phase
stator winding electrical resistance, the field winding
resistance, the direct and quadrature damping winding
resistances, the field winding leakage reactance, the
per phase stator winding leakage reactance, the
damping winding leakage reactances, and direct and
quadrature magnetizing reactances are possible to be
determined with some accuracy through specific tests
like the Potier reactance determination, the sudden
short-circuit test and the load rejection tests. This work
Abstract:
Abstract: This work consists in proposing a
methodology based on Fuzzy Logic to obtain an index,
which classifies the buses more suitable to install a
distributed generator in an electric power distribution
system. Themethodologywas developed taking into
consideration the difficulty tomaintain a suitable
voltage profile in distribution systems, so the
methodology results in large, index values for the
buses in which the installation of generators results in
a more suitable voltage profile. Another aspect
included in the methodology is the minimization of the
real power losses. Applying a set of fuzzy rules, the
69
index is calculated by setting membership values to
the bus 'voltage' and 'load real power'. The advantages
of this methodology are that the classification of the
variables into fuzzy sets, which allow the linguistic
translation of the system operator knowledge and so
his experience of operating the system can be
employed in the process of allocating distributed
generators in the system and when compared to
traditional techniques of analysis, does not need of
consecutive runs of power flows, it is necessary only
to obtain the state operating of the network through
only one power flow in base case
Keywords: Electric power distribution, Fuzzy logic,
Electrical energy distributed generation, Alternative energy
sources, Indexes
STUDY ABOUT ENERGY ECONOMY AND POWER
QUALITY
Estudo sobre conservação de energia elétrica e
qualidade de energia elétrica .
Caio Gomes De Oliveira
Supervisor: Fujio Sato (DSEE)
This work deals with two issues of large
relevance, especially in recent years about electric
power: energy economy and power quality. The
studies are based on data collected by various
measurement and energy management instruments at
different points in the Campinas State University
Campus (Unicamp), in São Paulo State, Brazil. The
performance of energy relates to its more efficiently
use and without wasting, which is important to
increase the amount of available energy, without large
investments in generation, transmission and
distribution, thereby reducing environmental impacts.
A Project has been developed, named Ecogera, whose
purpose is to evaluate the energy efficiency, through a
program of rational use and development of alternative
sources of energy. The module of energy economy is
discussed here, developed in units of consumption
with typical characteristics for the type of work
performed at the university, focusing on the reduction
of lighting consumption. A good power quality refers
to the absence of abnormal variations in voltage,
related to continuity of supply and the sinusoidal
waveform of the power supply. The power quality
problems have been increased over the years, mainly
due to the increase of nonlinear loads, the increased
sensitivity of the equipment and the large
interconnection of the power networks, and can result
in misoperation or damage of the devices. A greater
focus is given on the voltage amplitude disturbances
and the distortion in the waveform, showing its main
causes and means of overcoming them. In the first
case transients, interruptions, sags and swells are
recorded, adequate analysis are done, and their
influence on the equipment are evaluated by the ITI
Curve (CBEMA), which enables the determination of
possible damage or failures in them. In the second
Abstract:
70
case, the presence of harmonics is evaluated in the
various points of measurement, either by the analysis
of waveforms and its spectral content or by the total
harmonic distortion over a one-week period. Finally,
tree-phase electrical power theories are studied,
especially the Instantaneous pq Power Theory, which
is important in the application of active filters, whose
function is to reduce the harmonic currents generated
by nonlinear loads. The real measured data of the
instantaneous voltages and currents was put in a
computacional program developed from the
mathematical model of an active filter with parallel
compensation and using a compensation method based
on the Power Instantaneous Modified pq Theory and
its influence seem by the current supply is obtained by
the harmonic eliminations
Keywords: Electric power systems, Electric power, Eletric
power, Harmonic waves electric, Active electric filters
METHOD OF ANALYSIS OF VOIP TRAFFIC OVER
Método de análise de tráfegos VoIP sobrepostos
Marcos Eduardo Coelho Garcia
Supervisor: Leonardo de Souza Mendes (DECOM)
Abstract: The
behavior of VoIP traffic in network links
is addressed in this work. VoIP applications have strict
requirements for quality of service (QoS) that should
be provided for in the network design. In this sense,
the Markov Modulated Poisson Process (MMPP) is
displayed as model of process of arrivals that is
appropriate to characterize the behavior of
superposition of VoIP traffic sources. It is taken into
account that VoIP applications use the mechanism
Suppression of Silence to save bandwidth, which
makes the traffic very variable and with bursty
arrivals. In order to analyze the behavior of the link,
the MMPP/M/1 queue model is used. To evaluate the
viability of the model, comparative studies were made
with results of the ns-2 simulator
Keywords: Telecommunication traffic, Markov processes,
Internetworking (Telecommunication), IP networks,
Broadband communication systems
LOW COST INSTRUMENTED SPHERE FOR IMPACT
AND TEMPERATURE MONITORING DURING
POSTHARVEST PROCESSES
Esfera Instrumentada de Baixo Custo para
Monitoramento de Impactos e Temperatura durante
Processos Pós-colheita.
Murilo Nicolau
Supervisor: Fabiano Fruett (DSIF)
Brazil is one of the largest worldwide
producers of fruit and vegetables. However, the loss of
horticultural products due to physical damage and
thermal stress is estimated at about 30 % to 40 %,
even 50 % for certain products. The process that
degrades the quality of vegetables starts during its
harvest and can culminate in its disposal even before
Abstract:
Sinopse da FEEC
reaching the final consumer. The knowledge of the
variables that act in this waste generating process,
their influences and inter-relationships can help to
minimize the problem. In this work, we present a tool
capable of monitoring the impacts and temperature
during the postharvest. This instrument, called Fruta
Eletrônica, was designed to be an accessible tool for
the farmers. This instrument measures and stores
triaxial impacts from 0.5 g to 250 g and temperatures
between 0 C and 80 C. Field tests, carried out in an
orange packing line treatment in Eng. Coelho city,
show that this instrument can provide useful
information to assist identifying the points of
mechanical and thermal stress in which fruits are
submitted
Abstract: This work tackles with the problem of
dimensioning wireless networks through the analysis
of the outage probability aiming to contemplate
multiservice traffic. This is an intrincate task, since it
must consider aspects such as fading and interference
in the wireless channel as well as multiservice traffic.
First, an ad hoc network with only one class of service
is analysed through the joint outage probability. Then,
a novel closed formulation for the outage probability
in multiservice systems is found. This formulation was
promptly validated through discrete-event simulation.
Therefore, the proposed formulation may be used for
the dimensioning in multiservice wireless networks
without the necessity of simulations. This method
presents the advantages of easy implementation and
low computational effort. This means that this tool
enables a fast and precise dimensioning
Keywords: Artificial fruit, Precision agriculture, Injuries,
Accelerometer, Sensors
A STUDY ABOUT THE CONDITIONS FOR PERFECT
INVERSION AND NON-SUPERVISED
EQUALIZATION OF SISO, SIMO AND MIMO
CHANNELS
Um estudo sobre as condições de inversão perfeita
e de equalização não-supervisionada de canais
SISO, SIMO e MIMO
Michele Nazareth Da Costa
Supervisor: João Marcos Travassos Romano (DMO)
This dissertation was motivated by the idea
of developing a unified approach to the problem of
unsupervised equalization, in the context of SISO,
SIMO and MIMO channels. This approach is
concerned with two fundamental aspects of the
equalization problem: the structure of the equalizer
and the optimization of its parameters. In this sense,
we propose a same methodology to study, in the three
aforementioned scenarios, two different limitations.
The first one, which we denote structural limitation, is
related to the impossibility of inverting any channel
employing only finite impulse response (FIR) filters.
The second one, which we call criterion limitation,
refers to the limitation regarding the use of second
order statistics (SOS) to obtain the equalizer in an
unsupervised manner. In order to perform this
analysis, we collected results that are rather scattered
in the literature to formalize the concepts of invertible
and minimum-phase systems in all three scenarios.
Then, we use the concept of a prediction-error filter to
study the limitation of SOS in the equalization
problem
Abstract:
Keywords: Probabilities, Wireless communication systems,
Markov chains, Telecommunication, Radio
A PROPOSAL FOR A FORMAL SPECIFICATION
USING SDL OF AN INVEHICLE NETWORK BASED
ON THE FLEXRAY PROTOCOL WITH AUTOMATIC
JAVA CODE GENERATION
Proposta de Especificação Formal em SDL de uma
Rede de Comunicação Automotiva Baseada no
Protocolo FlexRay com Geração Automática de
Código JAVA.
Daniel Cesar Felisberto Rezende
Supervisor: Walter da Cunha Borelli (DT)
Keywords: Equalizers, Signal processing, Linear systems
This work presents a proposal of formal
specification using SDL for an in-vehicle network
based on the FlexRay protocol with automatic
generation of Java code. The proposed model is based
on that presented in the standard specification of the
FlexRay protocol, although some contributions were
made in order to generate a functional and executable
FlexRay network. The SDL model generated provides
the system a behavioural formalization, making it
possible to validate and simulate its key features and
critical cases by the use of the tool TAU SDL Suite.
After the system is modeled, simulated and validated
is generated Java code for implementing the system
created. For this reason it was developed a tool for
generating Java code that receives as input a file with
the specifications in SDL, and delivers as result a
system written in Java that makes use of sockets for
communication between processes
Abstract:
Keywords: Java (Computer program language), Computer
network protocols, SDL (Computer program language)
CONTRIBUTIONS ON THE DIMENSIONING OF
WIRELESS NETWORKS
Contribuições ao dimensionamento de redes sem
fio
Renata Valverde Mello
Supervisor: Michel Daoud Yacoub (DECOM)
71
IMPACT OF USING LIFTING TECHNIQUES TO
EXPLORE THE DIFFERENCES BETWEEN
INTERPRETED AND COMPILED TOOLS IN THE
COMPUTATIONAL SPEED OF WAVELET STATIC
IMAGE CODING
Impacto da Utilização de Técnicas de Lifting
Explorando Diferença entre Ferramentas
Interpretada e Compilada na Velocidade
Computacional da Codificação Wavelet de Imagens
Estáticas.
Lucas de Oliveira
Supervisor: Yuzo Iano (DECOM)
The field of analysis and compression of
images has been received special attention of the
scientific community because of including in the main
systems of digital TV, satellite communications and
mobile communications. In this context, the Discrete
Transform Wavelet (TWD) arise how a powerful tool
and its many advantages allowed your insertion in
important standards such as JPEG2000, MPEG4 and
MPEG7. The lifting method realizes the TWD subsampling the signal before the filtering, resulting in
faster processing by using the similarities between
high and low pass filters, speeding up the calculation
of coefficients. In the literature, arithmetic theoretical
gains of different proportions were obtained on the
traditional method, especially the works of Daubechies
and Sweldens and of Reichel. The objective of this
research is to extend this discussion of theoretical
results when implemented through tools, interpreted
and compiled, targeting the processing time required
to perform (decomposition and reconstruction) of
different images using wavelets belonging to the
families of Daubechies, and Symlets Biortogonais.
Measures of PSNR were used to corroborate the
perfect implementation of the lifting, since that cannot
result in deterioration in the reconstructed image
Abstract:
Keywords: Image processing, Coding theory, Wavelets
(Mathematics),
communications
Digital
compression,
Digital
CHANNEL STATE FEEDBACK FOR THE
DOWNLINKWITH MULTIPLE ANTENNAS
Realimentação de Informação de Canal para
Downlink com Múltiplas Antenas.
Fábio Gabrielli Fernandes
Supervisor: Renato da Rocha Lopes (DECOM)
Multiuser communication strategies, together
with the use of multiple antennas, result in better
performance when compared to the point-to-point
approach. However, they are highly dependent on
knowledge of channel state information at the
transmitter, which in general requires that the
receivers feed back the estimated channel. The focus
of this work is the problem of partial channel state
information at the transmitter in the downlink of a
wireless system composed of a central transmitter with
multiple antennas and several receivers with one or
Abstract:
72
more antennas each. A feedback method is proposed,
using zero-forcing beamforming, which aims to
achieve high sum rates while using the least amount of
feedback bits possible. The channel state information
is divided in channel direction and channel quality
information. The direction information consists of a
quantized version of the direction of the channel
vector, which can be seen as quantization in the
Grassmann manifold. We propose the use of a lower
bound on the signal-to-interference-plus-noise ratio of
each user, which assumes the selection of nearorthogonal users. The lower bound is derived, as well
as adjustments intended to add information available
at the transmitter side that lead to an increase in the
sum rates. Simulation results show that the proposed
method outperforms similar techniques in terms of
sum rate in most scenarios
Keywords:
MIMO systems,
communication systems, Broadcast
Feedback,
Wireless
SPECTRAL CHARACTERIZATION AND
PERFORMANCE EVALUATION FOR ADVANCED
DIGITAL OPTICAL MODULATION FORMATS AT 40
GB/S
Caracterização Espectral e Avaliação de
Desempenho para Formatos Avançados de
Modulação Digital Óptica em 40 Gb/s
Francisco Augusto Da Costa Garcia
Supervisor: Hélio Waldman (DECOM)
This work compares the performance of four
feedforward carrier recovery architectures in coherent
QPSK and 8-PSK receivers, with polarization
multiplexing and differential decoding. We focused on
the scenarios showing an SNR imbalance between
orthogonal polarizations, as in PDL impaired systems.
Using Monte Carlo simulations, we observed that the
proposed joint estimation method yields an SNR
penalty of 1.1 dB, for a laser linewidth/ baudrate ratio
of 5×10-3, while the other three investigated
architectures 1.8 dB, 2.0 dB and 3.9 dB, for the QPSK
modulation format. As for 8-PSK, the proposed joint
feedforward carrier recovery architecture exhibits a
1.1 dB SNR penalty for a laser linewidth/ baudrate
ratio of 7.5 × 10-4, while the other three architectures
1.5 dB, 1.7 dB and 2.8 dB, for a BER = 10-3 and 3 dB
SNR imbalance. Keywords: optical communication,
coherent receiver, phase modulation
Abstract:
Keywords: Optical communications, Phase modulation,
Optical coherent
A STUDY OF ALGORITHMS FOR INTERPOLATION
OF NUMERICAL SEQUENCES
Um Estudo Sobre Algoritmos de Interpolação de
Sequências Numéricas.
Eric Magalhães Delgado
Supervisor: Max Henrique Machado Costa (DECOM)
This dissertation presents a study on
interpolation and decimation algorithms of numerical
sequences, whose filters are derived from the ideal
Abstract:
Sinopse da FEEC
reconstruction filter. An adaptive algorithm of cubic
interpolation is proposed and the gains of this
algorithm is analized by comparing with the classic
algorithms. The idea is to explore the trade-off
between quality and complexity of the interpolation
filters. The adaptation of the filter, obtained from
spacial and spectral estimates of the sequence to be
interpolated, is useful because it provides an efficient
use of complex filter in critical regions as, for
example, regions of edge of an image. Simulations in
typical images show a significant quantitative gain of
the adaptive algorithm when compared to classical
algorithms. Furthermore, an interpolation algorithm is
analyzed based on the knowledge of the acquisition
process of the sequence to be interpolated
POLLUTANT DISPERSION IN RESERVOIR'S
SYSTEMS : MATHEMATICAL MODELLING USING
NUMERICAL SIMULATION AND FUZZY SETS
Dispersão de Poluente em Sistema de
Reservatório: Modelagem Matemática e Simulação
Computacional Utilizando-se Aproximação
Numérica e Conjuntos Fuzzy.
Elaine Cristina Catapani Poletti
Supervisor: Raul Vinhas Ribeiro (DENSIS)
Current work presents an instrument for
dispersion of water's surface pollutant study through
Mathematical Modelling and the main phenomenas
involved in this type of analysis. For this purpose, we
use the Partial Differential Equation of diffusionadvection that incorporates the dispersion accomplish
of the pollutant, its transport and decline, with
compatible initial and boundering conditions.
Numerical approximation well dimensioned are
defined and effective computational simulations
algorithms, are implemented which considered
independent variable, were developed. The
independent variable considered can be spatial as well
as temporary. As a case study, we use Salto Grande
reservoir situation, which is a dike of Atibaia river,
one of the most important public water sypply in an
important region of São Paulo state. In the descriptive
parameters of the problem, the option was the use of
fuzzy techniques sets that allow incorporating inherent
uncertainties to this situation
Abstract:
Keywords: Interpolation, Signal processing, Stochastic
process, Data reconstruction (Computer Science), Image
reconstruction
Doctoral thesis
Automation
ROBUST FILTERING TIME-DELAY MODELS AND
PERFORMANCE CERTICATE : APPLICATION TO
ELECTRIC SYSTEMS
Filtragem robusta, modelos com atrasos e
certificação de desempenho - aplicação a sistemas
elétricos.
Rubens Hideo Korogui
Supervisor: José Claudio Geromel (DSCE)
One of the themes considered in this work is
the robust H2 filtering design problem for linear time
invariant continuous and discrete time systems. We
assume that the systems are subject to parametric
uncertainty, initially of the polytopic type and later as
linear
fractional
transformation
parametric
uncertainties. We calculate lower and upper bounds to
the H2 squared norm of the estimation error by means
of the equilibrium solution of a minimax problem, that
can be formulated in a linear matrix inequality
framework. Under this approach we provide an
optimality gap that allows us to certify the
performance of the designed robust filter. Afterwards,
we apply the proposed methodology to estimation
problems involving a three-phase induction motor and
a transmission line with a stub. This work also
considers what we call a linear comparison system,
whose goal is to serve as an alternative to study timedelay systems. Using the Rekasius substitution we
construct a linear time invariant system that allows us
to get information about stability and H8 norm of this
class of systems. Based on this approach in terms of
state space matrices it is possible to extend the results
to state feedback design and filtering design without
any further assumptions
Keywords: Mathematical modelling, Diffusion, Pollutants,
Finite element method, Fuzzy sets
Abstract:
CONTROL AND FILTERING OF TIME-VARYING
LINEAR SYSTEMS VIA PARAMETER DEPENDENT
LYAPUNOV FUNCTIONS
Controle e Filtragem de Sistemas Lineares
Variantes no Tempo por meio de Funções de
Lyapunov Dependentes de Parâmetros.
Renato Alves Borges
Supervisor: Pedro Luis Dias Peres (DT)
Keywords: Linear systems, Control theory, Feedback
control systems, Filtering, Kalman
The main contribution of this dissertation is
to propose conditions for linear filter and controller
design, considering both robust and parameter
dependent structures, for discrete time-varying
systems. The controllers, or filters, are obtained
through the solution of optimization problems,
formulated in terms of bilinear matrix inequalities,
using a method that alternates convex optimization
problems described in terms of linear matrix
inequalities. Both affine and multi-affine in different
instants of time (path dependent)Lyapunov functions
were usedto obtain the design conditions, as wellas
extra
variables
introduced
bythe
Finsler's
lemma.Design problems that take into account an H
guaranteed cost were investigated, providing
robustness with respect to unstructured uncertainties.
Numerical simulations show the effciency of the
Abstract:
73
proposed methods in terms of H performance when
compared with other strategies from the literature
Keywords: Linear time invariant systems, Control theory,
Liapunov functions, Stability, Mathematical optimization
DYNAMIC OUTPUT FEEDBACK FOR DISCRETETIME MARKOV JUMP LINEAR SYSTEMS
Controle Dinâmico de Saída para Sistemas
Discretos com Saltos Markovianos.
Alim Pedro De Castro Gonçalves
Supervisor: José Cláudio Geromel (DSCE)
This work addresses the H2 and H? output
feedback design problem for discrete-time Markov
jump linear systems. Initially, we study the filtering
problem and propose different design techniques to
deal with the Markov parameter, often called mode,
availability and/or partly known transition probability.
The main result is the characterization of all linear
controllers such that the controlled output norm
remains bounded by a given level, yielding the
complete solution of the mode-dependent H2 and H?
linear control design problem. All controllers are
designed by solving linear matrix inequalities. The
theory is illustrated by means of practical examples,
consisting of control over data communication through
a markovian channel and of statistical modelling of
sensors/actuators failures
Abstract:
Keywords: Control Theory, Linear Systems, Stochastic
Systems, Markov Processes
STABILITY AND CONTROL OF LINEAR
STOCHASTIC SYSTEMS WITH LONG-RUN
AVERAGE COST CRITERION
Estabilidade e Controle com Critério de Custo
Médio a Longo Prazo em Sistemas Lineares
Estocásticos.
Alessandro do Nascimento Vargas
This monograph presents results on stability
and control of stochastic systems represented by linear
operators with respect to the state which are non-linear
with respect to the control. The control seeks to
optimize a long run average cost (LRAC). The control
structure does not depend on the past history of the
process and it can be used, in particular, to represent a
broad range of control problems that appears in the
literature. Regarding the stability, it is shown that the
stochastic system is asymptotically stable in the mean
if the LRAC is finite and if controllability and
observability assumptions are satisfied. To guarantee
the uniform second moment stability, some additional
conditions must be verified. With respect to the
control, the main goal is to assure the existence of an
optimal stationary policy for the LRAC problem
within the class of systems considered, and some
independent conditions are derived. An approximation
for the minimum LRAC is obtained, and it is
illustrated numerically for the regulator problem of
Abstract:
74
Markov jump linear systems, under the assumption
that the controller does not have access to the Markov
state. Numerical examples illustrate the derived theory
Keywords: Control theory, Stochastic systems, Linear
systems, Markov processes
CONTRIBUTION OF THE LU FACTORIZATION
UPDATE IN THE SIMPLEX METHOD
Contribuição da Atualização da Decomposição LU
no Método Simplex.
Daniela Renata Cantane
Abstract: Finding efficient solution of linear systems is
fundamental in the linear programming problems and
the first method to obtain success for this class of
problems was the Simplex method. With the objective
to develop efficient alternatives to its implementation,
techniques of the simplex basis LU factorization
update are developed in this thesis to improve the
solution of the Simplex method linear systems towards
a matrix columns static reordering. A simulation of the
Simplex method is implemented, carrying through the
change of basis obtained from MINOS and verifying
its sparsity. Only the factored columns actually
modified by the change of the base are carried through
to obtain an efficient LU factorization update. The
matrix columns are reordered according to three
strategies: minimum degree; block triangular form and
the Björck strategy. Thus, sparse factorizations are
obtained for any base without computational effort to
obtain the order of columns, since the reordering of
the matrix is static and base columns follow this
ordering. The application of the block triangular form
achieved the best results, for larger scale problems
tested, in comparison to minimum degree method and
the Björck strategy. Computational results for Netlib
problems show the robustness of this approach and
good computational performance, since there is no
need of periodical factorizations as used in traditional
updating methods. The proposed method obtained a
reduction of the nonzero entries of the basis with
respect to MINOS. This approach was applied in the
cutting stock problems and the proposed method
achieved a reduction of the computational time in the
solution of such problems with respect to the GLPK.
Keywords: Linear Programming, Simplex Method, LU
Factorization Update
DEPOSITION OF CARBON STRUCTURES BY
ELECTROCHEMICAL PROCESS THROUGH
ORGANIC SOLUTION AT ROOM TEMPERATURE
Deposição de Estruturas Carboníferas por
Processo Eletroquímico Através de Solução
Orgânica em Temperatura Ambiente.
Jackson Tsukada
Supervisor: Vitor Baranauskas (DSIF)
Sinopse da FEEC
This work describes the synthesis of carbon
materials by the liquid phase electrodeposition
technique performed at room temperature. During the
process of deposition, was used an electrolytic cell
with potential diference between the electrodes not
exceeding 300V. The solution used was pure ethanol
well as deionized water mixed with ethanol. The
samples were characterized by optical microscopy,
scanning
electron
microscopy
and
Raman
spectroscopy. Among the set of samples produced,
there were those that presented structures of DiamondLike Carbon (DLC) and diamond. The interest in the
liquid phase electrodeposition technique is justified by
the possibility of synthesizing carbon materials at low
temperatures
Abstract:
CMOS VOLTAGE REFERENCE WITH CURVATURE
CORRECTION
Referência de Tensão CMOS com Correção de
Curvatura.
Wellington Avelino Do Amaral
Keywords: Carbon, Electrolyte, Ethanol, Water
SI ANISOTROPIC ETCHING AND
NANOSTRUCTURED SURFACE FORMATION
USING HIGH DENSITY PLASMA
Corrosão Anisotrópica e Formação de Superfície
Nanoestruturada de SI Utilizando Plasma de Alta
Densidade
Clóvis Fischer
Supervisor: Jacobus Willibrordus Swart (DSIF)
This work explores the implementation,
characterization and applications of BOSCH type
process for bulk silicon etching (or bulk silicon
micromachining) using inductively coupled high
density plasma (ICP). This etching process is
characterized by its high anisotropy and is performed
by alternating etching steps, employing SF6 + Ar gas
mixture, and passivation steps, employing C4F8 + Ar
gas mixture. Ni-P metallic masks grown by electroless
over silicon substrate were employed, showing high
selectivity and thus allowing for long process times for
deep etching. The difficulties of process
implementation are discussed and a method to
implement it is shown, comprising plasma etching
with SF6 + Ar and fluorocarbon polimer deposition
with C4F8 + Ar plasma. With a BOSCH type process
developed, some experiments were performed aiming
to optimize the anisotropy and the etch rate, the effect
of process parameters on etching profiles was
discussed. Medium etching rates of about 1.5 µm/min
and vertical walls were achieved. The applications of
this process include: (1) fabrication of a pressure
sensor membrane and (2) fabrication of nanostructured
silicon surfaces like nanopillars and nanocones. The
nanocones surfaces are characterized by high light
absorption ("black silicon") presenting minimum
diffuse relectance of 0.91% at l = 783 nm, being
potentially of great interest for photovoltaic convertion
Abstract:
The objective of this work is to design and
prototype a CMOS voltage reference based on the
threshold voltage of the MOS transistor. The
innovation presented in this work is the use of an
original architecture with high performance. In the
laboratory measurements the circuit presented
11ppm/0C of variation. This performance is
comparable to the bandgap references. A temperature
sensor was also designed and presented a temperature
coefficient of 1mV/0C. Therefore, two circuits were
prototyped (the ceinv35 circuit and the ceinv66
circuit). The circuit ceinv35, using the trimmer
structures, can operate as a voltage reference or a
temperature sensor. The circuit ceinv66 was the main
topology studied. It uses a Vth extractor circuit, a
start-up circuit and an operational amplifier. The Vth
extractor circuit uses an original topology. In both
circuits (ceinv35 and ceinv66) were used trimmer
structures to make possible off-chip adjusts. In the
introduction chapter is presented an overview of the
circuits used as voltage references. Some bandgap
references and some techniques used to design CMOS
voltage references are analyzed. In chapter 2 are
shown the operation principles and the equations
extracted of the proposed circuit. In chapter 3 are
shown the simulation results. The circuit ceinv35
presented a temperature coefficient of 1mV/0C,
working as a temperature sensor. On the other side,
working as a voltage reference, the variation presented
was 4:06ppm/0C. The circuit ceinv66 presented a
variation of just 3:14ppm/0C. The chapter 4 covers the
layout design of the circuits. The AMS (Austria
Microsystems) technology with a minimum channel
length of 0:35_m was used. In chapter 5 are presented
the parasitic extraction simulations. After this analyses
new adjusts were made in the circuits. The trimmers
structures were used for this adjusts. In chapter 6 are
provided the experimental results of both circuits. In
chapter 7 is presented an alternative for the voltage
reference design without using a start-up circuit. In
this chapter is also presented a methodology for the
trimmers design. In chapter 8 are discussed the
proposed innovations and some conclusions about the
design presented
Abstract:
Keywords: Integrated circuits, Complementary metal oxide
semiconductors, Metal oxide semiconductors
Keywords: Silicon, Microelectronics, Sensors, Corrosion
75
SYNERGY BETWEEN ARTIFICIAL IMMUNE
SYSTEMS AND PROBABILISTIC GRAPHICAL
MODELS
Sinergia entre Sistemas Imunológicos Artificiais e
Modelos Gráficos Probabilísticos.
Pablo Alberto Dalbem de Castro
Supervisor: Fernando José Von Zuben (DCA)
Artificial immune systems (AISs) and
probabilistic graphical models are two important
techniques for the design of intelligent systems, and
they have been widely explored by researchers from
diverse areas, in both theoretical and practical aspects.
However, the potential of each technique is usually
explored in isolation, without considering the possible
cooperation between them. As a first contribution of
this work, it is proposed an approach that explores the
main advantages of AISs as optimization tools applied
to the learning of Bayesian networks from data sets.
On the other hand, the AISs already proposed to
perform optimization in discrete and continuous
spaces correspond to population-based meta-heuristics
without mechanisms to deal effectively with building
blocks, and also having few resources to benefit from
the knowledge already acquired from the search space.
The second contribution of this thesis is the
proposition of four algorithms devoted to overcoming
these limitations, both in single-objective and multiobjective contexts. The cloning and mutation operators
are replaced by a probabilistic model representing the
probability distribution of the best solutions. After
that, this model is employed to generate new solutions.
The probabilistic models adopted are the Bayesian
network, for discrete spaces, and the Gaussian
network, for continuous spaces. These choices are
supported by their ability to properly capture the most
relevant interactions among the variables of the
problem. Promising results were obtained in the
optimization experiments carried out, which have
treated, in discrete spaces, feature selection and
ensembles for pattern classification, and, in continuous
spaces, multimodal functions of high dimension.
Keywords: artificial immune systems, Bayesian
networks, Gaussian networks, optimization in discrete
and continuous domains, single-objective and multiobjective optimization
Abstract:
Keywords: Probability, Machine learning, Metaheuristic,
Optimization, Intelligent buildings
FROM PLANT MODELING TO CROWD DYNAMICS :
A BIO-INSPIRED BEHAVIORAL ANIMATION MODEL
Da Modelagem de Plantas à Dinâmica de Multidões:
Um Modelo de Animação Comportamental BioInspirado.
Alessandro de Lima Bicho
Supervisor: Léo Pini Magalhães (DCA)
This work presents a method for crowd
simulation based on the biologically-motivated space
Abstract:
76
colonization algorithm. This algorithm was originally
introduced to model leaf venation patterns and the
branching architecture of trees. It operates by
simulating the competition for space between growing
veins or branches. Adapted to crowd modeling, the
space colonization algorithm focuses on the
competition for space among moving agents. Several
behaviors observed in real crowds, including collision
avoidance, relationship of crowd density and speed of
agents, and the formation of lanes in which people
follow each other, are properties of the algorithm. The
proposed crowd modeling method is simple to
implement, robust, computationally efficient, and
suited to the interactive control of simulated crowds
Crowds, Human behavior, Computer
animation, Computer simulation, Computer graphics
Keywords:
PREDICTION OF PROTEIN-PROTEIN INTERFACE
REGION BASED ON STRUCTURAL INFORMATION
Predição de Regiões de Interface Proteína-Proteína
Baseado em Informações Estruturais.
Roberto Hiroshi Higa
Supervisor: Clésio Luis Tozzi (DCA)
This work approaches the problem of
protein-proteins interface region prediction based on
measures of physical-chemical and structural
properties. The approach considers the amino acids of
the protein surface as the basic units for classification,
such that the restriction of use of patches, considered
by similar predictors, is eliminated. This predictor is
complemented by a second one, which identifies,
among the interface amino acids, those which are most
relevant from the standpoint of protein-protein binding
energy. The classifiers can be used independently, for
predicting interface amino acids and hot spots. Unlike
other approaches for prediction of hot spots, described
in the literature, the proposed approach does not
depend on the knowledge of the protein structure in
complex. This allows predicting hot spots in
complement to the prediction of the interface amino
acids. Concerning the identification of hot spots, the
proposed predictor outperformed those, described in
the literature, which use the same data set and criterion
for performance evaluation
Abstract:
Keywords: Protein, Prediction, Pattern recognition
Electrical Energy
THE IMPACT OF URBANIZATION ON THE
DISTRIBUTION OF LIGHTNING INDUCED
VOLTAGES ON OVERHEAD LINES
O Impacto do Aumento da Urbanização nos Níveis
das Tensões Induzidas por Descargas
Atmosféricas nas Proximidades de Linhas de
Transmissão.
Fernando Zago
Some of the worst damage caused by
lightning is indirect, that is, it is caused by
Abstract:
Sinopse da FEEC
electromagnetic fields radiated from this kind of
natural phenomenon resulting in electromagnetic
compatibility problems or in challenges for designers
of surge protection systems and shields against these
interferences. This work considers one of these
indirect effects, induced voltages on overhead lines by
nearby atmospheric lightning discharges, using some
of the most recent research in the area of
electromagnetic fields generated by these natural
phenomena. Starting from a rigorous mathematical
formulation for a lightning channel, as well as for the
electromagnetic fields generated by them, for the case
of lightning striking the soil directly or an elevated
grounded object, it was possible to carry out a
comparative study of the urbanization effects close to
an overhead line with respect to the increase or
decrease of the induced voltages and currents when
nearby lightning discharges occur. These effects were
analyzed using computational simulations considering
variations in some parameters associated with
urbanization, such as: number of elevated objects,
elevated objects average height, different models for
the calculation of attractive radius and occupation or
urbanization density. Taking into account the research
and the computational program developed in this
work, methodologies to evaluate the modifications on
the occurrence patterns of lightning induced voltages
on overhead lines localized at different urban
occupation landscapes or at the vicinity of elevated
objects like telecommunication towers, were proposed.
not been obtained yet. Probably, for two parallel
double three-phase lines, considering future
development and searching for the exact single real
transformation matrix, the analyses are based on a
single homopolar reference. This suggestion is related
to that in the all analyses carried out in this work, the
homopolar mode is used as the only homopolar
reference for all phase conductors of the studied
system
Keywords: Eigenvalues, Eletric power transmission,
Eletric transmission, Eigenvectors
TOOLS AND METHODOLOGY FOR DATA
CONSOLIDATION FROM BRAZILIAN
HYDROELECTRIC PLANTS
Ferramentas e metodologia para consolidação de
dados de usinas hidreletricas brasileiras
Ieda Geriberto Hidalgo
Supervisor: Secundino Soares Filho (DENSIS)
This work presents tools and procedures for
the data consolidation from Brazilian hydroelectric
plants. The objective is to improve the quality of the
input data to the computational models used in the mid
and short term operation planning. As support tool to
the application of the methodology, are described: the
data manager HydroData, the queries builder
HydroConsulta and the simulator of the hydroelectric
plants operation HydroSim. The procedures sequence
is divided into two steps: analysis of the database
coherency and effective consolidation of the functions.
In the case study the methodology was applied to a
hydroelectric plant which is part of the National
Interconnected System and whose operation is under
the coordination and control of the Independent
System Operator. In order to evaluate the procedures,
were made studies of hydroelectric operation
reproduction, to the mid and short term, alternating
official data and consolidated data in accordance with
the technique presented. The results show that the
improvement of the data quality, obtained with the
application of the proposed methodology, brings the
simulated and real operation closer. This way, it
contributes to the efficiency, reliability and
performance analysis of the computational models in
use in the Brazilian electric sector.
Hydroelectric power plants, Planning, Data
processing, Data bases,
Abstract:
Keywords:
Lightning,
Electricity
atmospheric,
Telecommunication lines, Electromagnetic compatility,
Electromagnetic indution
SILGLE REAL TRANSFORMATION MATRICES
APPLIED TO DOUBLE TRHEE-PHASE
TRANSMISSION LINES
Matrizes de Transformação Reais Aplicadas as
Linhas de Transmissão de Circuito Duplo
José Carlos da Costa Campos
Single real transformation matrices are
applied as phase-mode transformation matrices of
typical symmetrical systems with double three-phase
and two parallel double three-phase transmission lines.
These single real transformation matrices are achieved
from eigenvector matrices of the mentioned systems
and they are based on Clarke's matrix. Using linear
combinations of the Clarke's matrix elements, the
techniques applied to the single three-phase lines are
extended to systems with 6 or 12 phase conductors.
For transposed double three-phase lines, phase Z and
Y matrices are changed into diagonal matrices in
mode domain. Considering non-transposed cases of
double three-phase lines, the results are not exact and
the error analyses are performed using the
eigenvalues. In case of two parallel double three-phase
lines, the exact single real transformation matrix has
Abstract:
Keywords:
TIME-VARYING MIMO CHANNEL ESTIMATION
USING KALMAN FILTERS
Estimação de Canais MIMO Variantes no Tempo
Usando Filtros de Kalman.
Murilo Bellezoni Loiola
Supervisor: Renato da Rocha Lopes (DECOM)
In this work we use Kalman filters to
estimate time-varying wireless channels in multiple-
Abstract:
77
input, multiple-output (MIMO) systems. First, we
propose an optimal estimator (in the minimum mean
squared error sense) to track flat channels in
orthogonal space-time block coded systems. Due to
the orthogonality inherent to these codes, the Kalman
filter equations can be simplified. We also show that
the channel estimates provided by the proposed
estimator correspond to weighted sums of
instantaneous maximum likelihood channel estimates.
For constant modulus signal constellations, we
propose a steady-state Kalman filter. The proposed
steady-state Kalman filter suffers negligible
performance degradation compared to the optimal
Kalman filter while requiring just a fraction of its
complexity. After that, we propose an extended
Kalman filter-based receiver that jointly performs the
estimation of time-varying frequency-selective MIMO
channels and the detection of transmitted signals in
spatial multiplexing systems. Finally, we adapt this
joint estimator to a turbo receiver. Therefore, the joint
estimator can benefit from the error correction
capabilities of channel codes to iteratively improve
channel and signal estimates
Keywords: Wireless communication systems, Kalman
filters, Signal processing, MIMO systems, Estimation theory
THEORETICAL CONTRIBUTIONS TO THE STUDY
OF CORRELATED DISTRIBUTIONS FUNCIONS OF
WIRELESS CHANNELS
Contribuições Teóricas para o Estudo de Funções
de Distribuição Correlacionadas em um Canal sem
Fio.
Rausley Adriano Amaral de Souza
Supervisor: Michel Daoud Yacoub (DECOM)
In wireless communications, the multipath
fading is modeled by several distributions including
Hoyt, Rayleigh, Weibull, Nakagami-m, and Rice. In
this thesis, new, exact expressions for the bivariate
Hoyt (Nakagami-q) processes with arbitrary
correlation in a nonstationary environment are derived.
More specifically, the following are obtained: joint
probability density function, joint cumulative
distribution function, power correlation coefficient,
and some statistics related to the signal-tonoise ratio at
the output of the selection combiner, namely, outage
probability and probability density function. The
expressions make use of the well known generalized
Laguerre polynomials. They are mathematically
tractable and flexible enough to accommodate a
myriad of correlation scenarios, useful in the analysis
of a more general fading environment. After this,
capitalizing on result previously deduced, exact
expressions concerning the bivariate Nakagamimprocesses with arbitrary correlation and fading
parameters are derived. More specifically, the
following are obtained in the present work: joint
moment generating function; joint probability density
function; joint cumulative distribution function; power
Abstract:
78
correlation coefficient; and several statistics related to
the signal-to-noise ratio at the output of the selection
combiner, namely, outage probability, probability
density function, and mean SNR. More recently, the
®-µ fading model has been proposed that accounts for
the non-linearity of the propagation medium as well as
for the multipath clustering of the radio waves. The ®µ distribution is general, flexible, and mathematically
easily tractable. It includes important distributions
such as Gamma (and its discrete versions Erlang and
Central Chi-Squared), Nakagami-m (and its discrete
version Chi), Exponential, Weibull, One-Side
Gaussian, and Rayleigh. An infinite series formulation
for the multivariate ®-µ joint probability density
function with arbitrary correlation matrix and nonidentically distributed variates is derived. The
expression is exact and general and includes all of the
results previously published in the literature
concerning the distributions comprised by the ®-µ
distribution. The general expression is then
particularized to an indeed very simple, approximate
closed-form solution. In addition, a multivariate joint
cumulative distribution function is obtained, again in
simple, closed-form manner. Approximate and exact
results are very close to each other for small as well
medium values of correlation. We maintain, however,
that a relation among the correlation coefficients of the
corresponding Gaussian components must be kept so
that convergence is attained
Keywords: Correlation, Probability density functions,
Fading, Diversity, Nakagami
MULTILEVEL HARMONIC BALANCE ANALYSIS OF
LARGE-SCALE NONLINEAR RF CIRCUITS VIA
NEWTON-KRYLOV AND TENSOR-KRYLOV
METHODS
Análise do Balanço Harmônico Multi-níveis para
Circuitos de RF Não-lineares em Grande-escala Via
os Métodos de Newton-Krylov e do Tensor-Krylov.
Oswaldo Pedreira Paixao
Supervisor: Hugo E. Hernandez Figueroa (DMO)
Abstract: This work deals with the development of
new techniques for nonautonomous nonlinear steadystate analysis of high-speed large-scale integrated
circuits. To this end, it is proposed a novel harmonic
balance (HB) method fundamented on a efficient
multi-level decomposition methodology, that divides a
large-scale circuit into hierarchical structure of
sparsely interconnected supernetworks (SuNs). More
precisely, the circuit is composed by intermediary
SuRs, bottom SuRs and connection networks (CNs).
The bottom SuNs are decomposed into a cluster of
nonlinear subnetworks (NSNs) corresponding to the
opto-electronic semiconductor devices, which in turn,
are embedded by a linear subnetwork (LSN). Multiport elements can be included in the LSN, in order to
use measured data or results from electromagnetic
analysis of structures with complex geometries. The
Sinopse da FEEC
formulation of the bottom SuN state and probe
equations uses an improved table-oriented statespace
formulation (SSF), that produces a square system with
the lowest possible size, which is equal to the number
of nonlinear state-variables (branch voltages and
currents) that act as argument of the fuctions
representing the semiconductor devices nonlinearities.
The SSF is compared with the classical modified
nodal formulation (MNF). For dealing with signal
timefrequency conversions, discrete Fourier transform
(DFT) techniques for different multi-tone regimes are
discussed, including complex digitally modulated
signals. The multi-level HB determining equation of
the circuit assumes a hierarchical block bordered
structure that can be efficiently tackled by parallel
processing techniques. The HB jacobian matrix is
handled using efficient sparse matrix techniques with a
proper definition of the derivatives spectra. For the
solution of a large-size HB problem, we investigated
the applications of inexact tensor method based on
Krylov-subspace techniques. Preconditioning are used
to improve the robustness of the iterative tensor solver.
To determine the circuit DC regime, we employ the
tensor method. We adopted the backtracking
linesearch technique as a globalisation strategy.
However, for the tensor method, in particular, a
curvilinear linesearch was also implemented. Finally,
the formulation was validated and, the tensor and
inexact tensor method efficiency was compared with
the Newton and inexact Newton method, respectively,
for several different circuits using diodos, FETs and
HBTs, and operating under different multi-tone
regimes
prices mechanisms, negotiation inside and outside of
the administrative domain and control of commercial
transactions of the sharing processes. The individual
satisfactions reached based on the well succeed
sharing were appraised in order to determine their
influences in the continuity of the market
Keywords: Grid computing (Computer systems), Electronic
data processing, Economics models
LOCALIZED BEAMS IN OPTICAL TWEEZERS WITH
CONVENTIONAL AND METAMATERIAL
PARTICLES
Feixes localizados em pinças ópticas com
partículas convencionais e metamateriais.
Leonardo André Ambrósio
Supervisor: Hugo Enrique Hernández Figueroa (DMO)
Keywords: Space-times, Semiconductor devices, Nonlinear
electric circuits, Fourier analysis, Computer-assisted
design
STRATEGIES FOR COMPUTATIONAL RESOURCES
TRADING IN DESKTOP GRIDS
Estratégias para Comercialização de Recursos
Computacionais em Desktop Grids
Lourival Aparecido de Gois
Supervisor: Walter da Cunha Borelli (DT)
In this thesis, we explore some applications
of localized beams in FSO - Free Space Optics - and
optical tweezers, greater emphasis been given to the
second one. For FSO, we show that it is possible to
choose the desired longitudinal intensity pattern by
using optical elements adequately modeled in their
phase functions: the axicons. In this way, these beams
could be uses for optical alignment of the link. In the
case of optical tweezers, we investigate the possibility
that it will soon be possible to design and build
homogeneous spherical particles, in the micron scale,
with negative refractive index (the so called DNG
particles, or Double-Negative particles), and we verify
some properties related to optical trapping, both for
Gaussian and Bessel beams, in the optics ray regime
and in the more general electromagnetic case. The idea
that particles with refractive index higher than the
medium in which it is immersed is attracted to regions
of high intensity, whereas it is attracted to regions of
low intensity when its refractive index is lower than
the medium, although valid for conventional particles
- those with positive refractive index - must be
revisited for DNG particles
Abstract:
Keywords: Laser beams, Metamaterials, Optical tweezers,
Diffraction, Electromagnetics
The association of idle machines in desktop
grids architectures represents a significant progress in
the solution of complex problems in areas as science,
engineering, trade and others. The difficulty in the
implementation and in the continuity of these
architectures is to maintain the levels of availability
demanded by their users. In its majority, the users are
constituted by volunteers that share their resources
without any formalized commitment. This thesis
proposes strategies for the design of a resources
administration system called DGridE - Desktop Grid
Economy, based on the microeconomics principle of
traditional markets of goods and services. This
approach allowed the structuring of a computational
resource market through the utilization of formation
Abstract:
79

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