Subhash C. Sinha, Department of Mechanical Engineering, Auburn University, USA.
Abstract. A general framework for the analysis and control of parametrically excited linear/nonlinear dynamical systems is presented. This class of problems appears in the modeling of rotorcraft blades in forward flight, asymmetric rotor-bearing systems, automotive components such as connecting rods, universal joints, asymmetric satellites, fluids under gravity modulations, etc. These dynamical systems are represented by a set of differential equations which contain time-periodic coefficients. First, an efficient computational scheme for the solution of linear problem is discussed through an application of Chebyshev polynomials. The idea is further developed to obtain the Lyapunov-Floquet (L-F) transformation associated with a linearized or a quasilinear time-periodic dynamical system. An application of L-F transformation yields equivalent systems whose linear parts are time-invariant. Therefore, the controls for all time-periodic linear systems can be designed using the standard time-invariant methods such as pole placement or optimal control theory. A symbolic control technique for Floquet multiplier placement is also suggested for linear time-periodic systems. In the case of nonlinear systems, a periodic orbit in the original coordinates has a fixed point representation after the L-F transformation. The local stability and bifurcation analyses are studied via time-dependent center manifold reduction and normal form theory. Results for fold, flip and secondary Hopf bifurcations are discussed. Bifurcation control and feedback linearization techniques for nonlinear time-periodic systems are also developed and applied to some typical problems. Further, the order reduction problem associated with free and forced parametrically excited large-scale nonlinear systems is also addressed using an invariant manifold approach. A methodology for reduced order controller design is also suggested. The practical significance of these approaches is demonstrated through simulations and experimental investigations of a number of mechanical systems. These include vibration control of a multi-bladed rotor, shafts supported by magnetic bearings, bifurcation analyses of a flexible slider crank mechanism and an autoparametric mechanical system, among others.
Celso Greboggi, University of Aberdeen, Great Britain.
Abstract. The traffic dynamics can be studied by considering the current of particles on a lattice, where to each lattice site a different hopping probability is associated and the particles can move only in one direction. I will show that a traffic jam of particles behind a slow site can lead to a first-order phase transition, and derive analytical expressions for the stochastic configuration of slow sites for this to happen. I will apply this traffic-engineering model to describe the translation of mRNAs and show that the first-order phase transition, uncovered in this work, is the process responsible for the classification of the proteins having different biological functions.
Hans Weber, PUC-Rio, Brazil.
Abstract. Some mechanical systems may present a regular vibration pattern that is strongly related to its normal operation. Usually one foresees damping mechanisms to reduce these undesirable side effects. On the other hand, there may occur applications where these mechanical systems undergo a stick-slip condition and, in this case, one could think on a subsystem able to produce impacts strong enough to liberate the stick condition. Ideally this subsystem would make use of some of the energy of the vibration. The example we focus is the oil well drilling with tricone bits which produce a tri-lobular cutting surface on hard rocks and forces a longitudinal vibration in the bottom hole assembly (BHA). The subsystem is an elastically suspended hammer embarked in the BHA which operates near resonance and generates impacts. The stress wave propagates to the drill bit, where it helps the dynamic load to fragment the rock. As a result an increase in the rate of penetration is expected. There were done several investigations along the last years to improve the performance of the device. Its operation was modeled considering a hammering process embarked in a moving platform. The investigation concerns the development of a reliable model to improve the design of a ready to use hammer for a specific application. Several interesting dynamic problems occur in the solution. Its complexity is summarized in the Peterka map, which shows the different regions of a certain number of impacts in relation to the vibration cycle of the platform. Regions of maximum impact force are defined experimentally validating the analytic model. Bifurcation diagrams, Poincaré maps, jumps, chaos in the transition regions are shown. The behavior of the model can be visually and acoustically followed in the experiment.
Martha Herr, UNESP, Brazil.
Abstract. As a relaxing moment, before the day happy hour, we include a short musical program with works from the light classic grouping cabaret music by classical composers in English and a quick introduction to Brazilian songs. Presented by two professors from the Arts Institute of Unesp, soprano Martha Herr and pianista André Rangel. Program: Benjamin Britten Calypso George Gershwin The Man I Love Kurt Weill It Never Was You Willaim Bolcom George Amor Heitor Villa-Lobos Food for Thought Viola Quebrada Chiquinha Gonzaga Lua Branca Edmundo Villani-Côrtes Valsinha de Roda Guilherme Terra Piqueira (The last two pieces on the program are directly related to Unesp Villani-Côrtes taught at the school and Guilherme Terra was a student.)
Alexander P. Seyranian, Institute of Mechanics,, Russia.
Abstract. A new multiparameter bifurcation theory of eigenvalues of matrix and linear differential operators is presented which is a key point for stability study of systems with finite degrees of freedom as well as distributed systems. Two important cases of strong and weak interactions (collisions) are distinguished and geometrical interpretation of these interactions is given. The presence of several parameters and the absence of differentiability of multiple eigenvalues constitute the main mathematical difficulty of the analysis. With presented multiparameter bifurcation theory of eigenvalues we analyze singularities of stability boundaries and give a consistent description and explanation for several interesting mechanical effects like gyroscopic stabilization, flutter and divergence instabilities, transference of instability between eigenvalue branches, destabilization and stabilization by small damping, disappearance of flutter instability, parametric resonance in periodically excited systems etc. A significant part of the work is devoted to difficult stability problems of periodic systems dependent on multiple constant parameters. This subject has been a challenge for more than one hundred years since Mathieu, Floquet, Hill, Rayleigh, Lyapunov, Poincare. From the very beginning these problems were multiparameter. In the present work, with the bifurcation theory of multipliers, geometrical description of the stability boundary and its singularities for periodic systems is given. Then we formulate and solve parametric resonance problems for one- and multiple degrees of freedom systems in three-dimensional space of physical parameters: excitation frequency, amplitude, and viscous damping coefficient. The main result obtained here is that we find the instability (parametric and combination resonance) domains as half-cones in three-parameter space with the use of eigenfrequencies and eigenmodes of the corresponding conservative system. The experiments on parametric resonance of pendulums and elastic beams confirm validity and accuracy of the obtained theoretical results. The swing problem is undoubtedly among the classical problems of mechanics. It is known from practice that to set a swing into motion one should erect when the swing is in limit positions and squat when it is in the middle vertical position, i.e. carry out oscillations with double the natural frequency of the swing. However in the literature you can not find formulae for instability regions explaining the phenomenon of swinging. In the present paper the simplest model of the swing is described by a massless rod with a concentrated mass periodically sliding along the rod axis. Based on analysis of multipliers the asymptotic formulae for instability (parametric resonance) domains in three-dimensional parameter space are derived and analyzed. Another classical problem is the problem of finding instability regions for a system with periodically varying moment of inertia. An equation describing small torsional oscillations of the system with periodic coefficients dependent on four parameters including damping is derived. Analytical results for instability (parametric resonance) regions in parameter space are obtained and numerical examples are presented. A problem of stabilization of a vertical (inverted) position of a pendulum under high frequency vibration of the suspension point is considered. Small viscous damping is taken into account, and periodic excitation function describing vibration of the suspension point is assumed to be arbitrary. A formula for stability region of Hills equation with damping near zero frequency is obtained. For several examples it is shown that analytical and numerical results are in a good agreement with each other. An asymptotic formula for stabilization region of the inverted pendulum with arbitrary periodic excitation function is derived. It is shown that the effect of small viscous damping is of the third order, and taking it into account leads to increasing critical stabilization frequency.
Clayton Bernardo, Instituto Tecnológico de Aeronáutica, Brazil - Fábio Alonso da Silva, ITA - Instituto Tecnológico de Aeronáutica, Brazil - Luiz Carlos Sandoval Goes, Instituto Tecnologico de Aeronautica, Brazil.
Abstract. Este artigo apresenta um estudo teórico e experimental da modelagem e caracterização de um sistema manipulador com dois elos flexíveis. Após a obtenção dos resultados teóricos e experimentais é feita uma análise comparativa não paramétrica com o objetivo de verificar a precisão associada ao modelo não paramétrico obtido na teoria.
Eduardo Godoy, São Carlos School of Engineering - University of São Paulo, Brazil - Bruno Nunes Bragato, Escola de Engenharia de São Carlos -USP, Brazil - Luciano Lulio, Universidade de São Paulo, Brazil - Arthur José Vieira Porto, USP - São Carlos, Brazil - Ricardo Inamasu, EMBRAPA Brazilian Agricultural Instrumentation Research Corporation, Brazil.
Abstract. Sistemas de controle via redes (NCS Networked Control Systems) representam uma inovadora abordagem para aplicação de sistemas de controle que utilizam redes industriais. Este trabalho investiga o desenvolvimento de NCS via rede CAN (Controller Area Network) discutindo implementações de hardware e software e apresentando os principais conceitos dessa tecnologia. Resultados obtidos a partir de dois NCS implementados permitem avaliar o desempenho desses sistemas sob diferentes configurações e comprovar a importância do período de amostragem em seu desempenho.
Thiago Raniel, Universidade Estadual Paulista, Brazil - Jozue Vieira Filho, Universidade Estadual Paulista (UNESP), Brazil.
Abstract. This paper proposes a spindle position control of a three-phase induction motor applied in a conveyor using a microcontroller, a frequency inverter, an optical incremental encoder and an inductive sensor. The microcontroller controls the inverter by USS communication protocol, using the RS-485 standard. The control software calculates the speed of the motors spindle and determines the point of trajectory that the microcontroller must start sending messages to the braking of induction motor. The tests were performed with a pitch of 13.2cm (360 mechanical degrees observed in the output of the reducer), presenting an error of 1.3cm, with percentage error of 9.85%, being this a very good result.
Marcelo Lopes, José Santisteban, Universidade Federal Fluminense, Brazil - Afonso Nero, Federal University of Rio de Janeiro-UFRJ, Brazil.
Abstract. Different aspects are considered in the design of active magnetic bearings (AMB), such as the mechanical one, the electronics and the control. Until now, we have tested some control techniques in a prototype of electric induction motor whose rotor is hovered by AMB´s. Nevertheless, these were of the decentralized type, which means that the different freedom degrees are considered decoupled, so the classic control theory may be utilized. Different to that approach, in this work the developing of a centralized control system is shown. In this way the plant is considered as a real multiple input multiple output (MIMO) system. Additionally, it was designed an optimal controller using the LQR (Linear Quadratic Regulator) strategy with an integral characteristic. Some simulations and experimental results confirm the good performance of this approach.
Antonio Valdiero, Carla Ritter, Cláudio Rios, UNIJUÍ, Brazil - Marat Rafikov, UFABC, Brazil.
Abstract. This paper addresses a new methodology for servo pneumatic actuators mathematical modeling in engineering applications. The nonlinear mathematical model represents main system characteristics. Simulation results show the dynamic performance in order to see which features contribute to a better behavior. Knowledge of this behavior allows the success in several applications.
Eduardo Padoin, UNIJUÍ, Brazil - Odair Menuzzi, UNIJUI, Brazil - Antonio Valdiero, UNIJUÍ, Brazil - Luiz Rasia, UNIJUI, Brazil.
Abstract. Este trabalho trata da modelagem matemática e da simulação computacional dos efeitos da não linearidade de folga (backlash) em transmissões mecânicas utilizadas no acionamento de juntas rotativas de robôs manipuladores. A partir da modelagem, avalia-se computacionalmente o comportamento da folga em um trem de engrenagens da junta de um robô.
Odair Menuzzi, UNIJUI, Brazil - Eduardo Padoin, Antonio Valdiero, UNIJUÍ, Brazil - Luiz Rasia, UNIJUI, Brazil.
Abstract. Trata-se da modelagem matemática e da simulação computacional dos efeitos da não linearidade de folga no acionamento de uma transmissão tipo fuso de um robô Gantry. A modelagem matemática da folga pode contribuir para estratégias de controle preciso e para melhoria do desempenho de robôs de baixo custo.
Fábio Lucio Corrêa Junior, Daniel Rocha, Tálita Sono, Kátia Meneses, Marcos Pinotti, UFMG, Brazil.
Abstract. Hand orthosis are useful to patients with central or peripheral nervous system injury affecting hand function and dexterity. This paper describes a control module design of the hand orthosis developed at the Laboratory of Bioengineering (LabBio) of the Federal University of Minas Gerais (UFMG). The functional hand orthosis is divided in three parts: glove, eletromechanical actuator and control module. The glove was constructed using anti-allergic elastic material to provide comfort and accommodation during its use on the patient''s hand. The glove biomechanical action is performed by artificial tendons with high mechanical resistance, low weight and a small diameter, disposed in a net form. Additionally, a servomotor was attached to tendons structure acting in the glove movements. The control module performs EMG signals processing and generates a resultant electrical signal to control the orthosis. The control strategy was based on EMG signals aquisition from two auxiliary healthy muscles groups, which were stimulated consciously by patients. The groups were chosen so that one was responsible by the opening command and the other by the closing command of the orthosis. The muscle groups were previously through a clinical review realized in patient by a physiotherapist. The functional hand orthosis was assembled and tested in patients who had hand movement paralysis. The design incorporated aspects of low cost and weight, power save, usability, high autonomy of functioning, ergonomics and more.
Cayo Francisco, Universidade Federal do ABC, Brazil.
Abstract. O problema de rotação entre dois cilindros concêntricos representa um paradigma para o estudo instabilidades em escoamentos fluidos e outros sistemas. O físico britânico Geoffrey Ingram Taylor (1886-1975) foi o grande pio- neiro dos estudos deste sistema físico. A configuraçao geométrica simples do sistema acaba por esconder toda sua riqueza dinâmica. A rotaçãao do cilindro interno leva ao aparecimento de instabilidades no fluido, criando o famoso padrao de vórtices toroidais observado por G.I. Taylor em 1923. Após o surgimento desta instabilidade primária podemos identificar transições e caracterizar uma dinâmica incrivelmente complexa. Ainda hoje, o problema do escoamento entre cilindros concêntricos surpreende-nos com a descoberta de novos comportamentos dinâmicos. Recentemente, uma variedade de novos padrões têm sido descoberta neste sistema, principalmente em função dos esforços do Prof. Harry L. Swinney da Universidade do Texas e seus colaboradores.
Kelly Iarosz, Antonio Batista, Universidade Estadual de Ponta Grossa, Brazil - Ricardo Viana, Sergio Lopes, Universidade Federal do Parana, Brazil.
Abstract. We study the firing rate properties of a cellular automaton model applied on small-world neuronal network. We propose a simple mechanism in that the non local connections are included, in order to consider chemical synapses. The results indicate a range of the probability of the connections, where the firing rates occur, as well as, the firing rate ceases for a critical probability. The value of the critical probability of non local shortcuts depends on the network size according to a power-law decay. Therefore, we also study the amplification factor varying the probability of connections for some network sizes.
Juliana Kodaira, Universidade Estadual Paulista "Julio de Mesquita Filho" - campus de Botucatu, Brazil.
Abstract. The SIR (susceptible; infected; recover) model has been extensively used to describe dynamics of a lot of diseases. We work with two kind of the SIR model, i.e., with and without treatment of infection compartment. In this paper, we present for this models the effect of the uniform random perturbations in the some parameters in the basic reproduction number (R0) using the Monte Carlo simulation technique, which produces uncertainty in R0. The results show that the uncertainty related to the basic reproduction number R0, performed by the Monte Carlo simulation technique, is useful to describe the effects of the parameters changes in the SIR dynamic systems models.
Julian Villamarin, Universidade de São Paulo, Brazil - Jaime Mosquera Sánchez, Universidade de São Paulo, Brazil.
Abstract. Este trabalho apresenta um procedimento computacional para determinar o coeficiente de atenuação ultrassônico _ dB/mm/MHz de amostras biológicas de suíno a partir do processamento de sinais de ultra-som mediante a aplicação do Filtro de Wiener. Foram coletados sinais retroespalhadas de ultra-som a partir de três tipos diferentes de amostras biológicas: 1) pele, 2) gordura sob-cutânea e 3) músculo. Desse modo, assumindo o meio de propagação como se fosse um Filtro de Wiener, foram determinados os coeficientes h(n) para segmentos de sinais de ultra-som correspondentes a características ecogênicas na entrada e saída do meio de propagação em estudo. A estimativa de h(n) permite determinar a resposta em frequência H(ejw) do Filtro. Mediante um ajuste linear na largura de banda de H(ejw) é obtido como resultado o coeficiente angular que indica a taxa de decremento de energía durante a propagação na amostra biológica. Os cálculos anteriores permitiram estimar o coeficiente de atenuação β para pele, gordura sob-cutânea e músculo sendo: 0.1444 dB/mm/MHZ, 0.0460 dB/mm/MHz e 0.0058 dB/mm/MHz respectivamente. Os resultados obtidos foram comparados com os resultados fornecidos mediante a técnica da diferença espectral. Os resultados foram razóaveis em comparação com valores citados na literatura.
Elizabeth de Holanda Limeira, Universidade Federal do ABC (UFABC), Brazil - Marat Rafikov, UFABC, Brazil.
Abstract. Neste trabalho foi proposto um modelo novo que considera interação da praga Diatraea saccaralis com seu parasitóide Trichogramma galloi. Foram encontrados os pontos de equilíbrio do sistema e foi investigada a estabilidade de cada um deles. As simulações numéricas mostraram uma boa aproximação qualitativa às interações que acontecem em sistemas reais: nos resultados de simulações foram observadas oscilações com quatro picos durante um ano, exatamente o que acontece num sistema real.
Tatiane Nishiwaki, Universidade Federal do ABC, Brazil - Marat Rafikov, UFABC, Brazil.
Abstract. Ethanol is a good choice as a fuel and additive. The increase in world demand for ethanol will bring an increase of the sugarcane planted in Brazil. One of challenges of the improvements in the farming and harvesting of cane is the biological pest control. The aim of this paper is to apply methods from optimal control theory, and from the theory of dynamic systems to the mathematical modeling of biological pest control. The nonlinear feedback control problem for nonlinear systems has been formulated in order to obtain the suboptimal pest control strategy only through the introduction of natural enemies. Numerical simulations for possible scenarios of biological pest control based on the LotkaVolterra models are provided to show the effectiveness of this method.
Rodolfo M. Almeida, Elbert E. N. Macau, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. A stochastic cellular automata model for wildland fire spread under flat terrain and no-wind conditions is proposed and its dynamics is characterized and analyzed. Each cell is characterized by one of the three states that are: vegetation cell, burning cell and burnt cell. The dynamics of fire spread is modeled as a stochastic event with an effective fire spread probability S which is a function of three probabilities: the proportion of vegetation cells across the lattice, the probability of a burning cell become burnt, and the probability of the fire spread from a burning cell to a neighbor vegetation cell. A set of simulation experiments are performed to analyze the effects of different values of the three probabilities in the fire pattern. The effective fire spread probability is obtained from Monte-Carlo simulations and a critical line that separate the set of parameter or which a fire can propagate from those for which it cannot is obtained. Finally, the relevance of the model is discussed in light of results of simulation experiments carried out that illustrate the capability of the model catches both the dynamical and static qualitative properties of fire propagation.
Henrique Kajino, Elenice Stiegelmeier, Vilma Oliveira, Universidade de São Paulo, Brazil, Décio Karam, Embrapa, Brazil.
Abstract. O problema da resistência de plantas daninhas aos atuais herbicidas utilizados é de grande importância econômica devido aos altos custos que envolvem o controle desta praga, e também ecológica já que o uso de dosagens maiores e herbicidas mais eficientes gera impactos ambientais. Modelos matemáticos que visam estudar a resistência a herbicidas não consideram a eficiência da dosagem utilizada e suas implicações na dinâmica da evolução genética das plantas daninhas. Este trabalho visa modelar esta dinâmica de evolução da resistência de plantas daninhas a herbicidas de modo que possa ser utilizada como ferramenta em outros modelos de manejo de plantas daninhas. O modelo pode ser explicado através de relações observadas entre a dinâmica genética e a resposta de mortalidade de plantas daninhas em relação a diferentes doses de herbicida.
Wanderson Texeira, Universidade Federal de São João del-Rei, Brazil - Botelho Thayane, Universidade Federal de São João Del Rei, Brazil - Erivelton Nepomuceno, Universidade Federal de São João del-Rei, Brazil - Alisson Daniel de Macedo-VItor, Fernando Teles, UFSJ, Brazil.
Abstract. As relações sociais mostram-se cada vez mais complexas e intrincadas atualmente, tornando-se um grande desafio contemporâneo a modelagem das mesmas. Nesse trabalho, fez-se uso dos conceitos de sistemas e redes complexas através da modelagem baseada em indivíduos afim de se modelar uma rede social e analisar seu fluxo de informação. Foram realizadas duas abordagens distintas, sendo em um primeiro momento atacados os indivíduos de forma aleatória e outra na qual os primeiros receptores da informação eram os que possuíam o maior número de ligações na rede.
Samuel da Silva, Universidade Estadual do Oeste do Paraná, Brazil.
Abstract. The present paper is concerned with the nonparametric identification of mechanical systems with mild nonlinearities using a Wiener-Volterra model. The paper employs some classical developed results to describe the discrete-time Volterra models using orthonormal Kautz functions. If the two parameters of these filter sets, associated with a Volterra series truncation, are properly designed, the number of parameters needed to represent the Volterra kernels is drastically reduced. Numerical tests illustrate the results by detecting the first-order and the second-order Volterra kernels
Rosemaira Copetti, UFSM, Brazil - Julio Claeyssen, Universidade Federal do Rio Grande do Sul, Brazil - Teresa Tsukazan, UFRGS, Brazil.
Abstract. This paper deals with the eigenanalysis of an Euler-Bernoulli beam subject to external viscous damping with a viscous damper attached at its free end. The eigenanalysis is formulated in terms of a fundamental response. Dynamic responses can be obtained by computing a convolution involving the fundamental response.
Joao Carvalho, Julio Claeyssen, Universidade Federal do Rio Grande do Sul, Brazil.
Abstract. In recent contribution, we proposed a method for computing the largest and the smallest natural frequencies of a second-order linear system knowing its mass, damping and stiffness matrices. The proposed method was a generalization of the well-known direct and inverse power methods for computing dominant and submissive eigenvalues of a matrix, and applied recent results on fundamental solutions for second-order systems, as well as the widely used technique of subspace iteration. We present now further investigation on preconditioning techniques for speeding-up the convergence to real extreme eigenvalues of a second-order system (M,C,K). The method can be applied to both sparse and dense problems, and strategies using specialized software libraries as LAPACK or SPARSEKIT can be deployed for achieving outstanding performance. Numerical examples with test matrices from real structural vibration problems are provided.
Edson Castilho Filho, Vinícius Fernandes, UNESP - Universidade Estadual Paulista (Campus Ilha Solteira), Brazil - Gilberto Melo, Universidade Estadual Paulista (Campus Ilha Solteira), Brazil.
Abstract. The main purpose is to develop a new tool for fault diagnosis in continuous systems. A methodology to generate banks of state observers associated to a crack model was created in order to analyze the fault progress. A computational routine simulates the system that have been modeled trough the Finite Element Method, and a system of a vibrating cantilever beam, with displacement and velocity monitored, were used to do the experimental validation of the method and evaluate its applicability.
Aldemir Cavalini Jr, Universidade Federal de Uberlândia, Brazil - Thiago Vianna Galavotti, UNESP Faculdade de Engenharia de Ilha Solteira, Brazil - Tobias S. Morais, Edson H. Koroishi, Valder Steffen Jr, Universidade Federal de Uberlândia, Brazil.
Abstract. This paper proposes a semi-active vibration control technique dedicated to a rotating machine passing by its critical speed during the transient rotation, by using a Smart Spring Mechanism (SSM). A Genetic Algorithm (GA) optimization technique is used to determine the best design of the SSM parameters with respect to performance indexes associated with the control efficiency. Additionally, the concept of ecologically correct systems is incorporated to this work including the PZT stack energy consumption in the indexes considered for the optimization process.
André Fenili, UFABC, Brazil - Cayo Francisco, Universidade Federal do ABC, Brazil.
Abstract. O estudo das interações entre fluidos e estruturas é extremamente complexo e fascinante. Também, do ponto de vista prático, encontra aplicações nos mais diversos ramos da engenharia. Nosso objetivo com este minicurso consiste em apresentar aos partici- pantes uma aproximaçao relativamente simples deste tipo de interaçao. No presente caso, temos uma viga flexível, ligada a uma motor DC e queremos abordar o problema de seu controle, se consideramos, além das equaçoes dinâmicas o trabalho de arrasto realizado pelo fluido ambiente. Veremos que os comportamentos antes obtidos sem a consideraçao do efeito de arrasto, diferem dos obtidos qundo incluímos, ainda que de maneira simples, este efeito. Esperamos que todos aproveitem o curso e achem-no prazeroso, da mesma forma que nos foi prazeroso prepará-lo.
Jerzy Warminski, Lublin University of Technology, Poland.
Abstract. Interaction between different vibration types may lead to very interesting and untypical phenomena [1]. Interest of this paper, in particular, is to determine Nonlinear Normal Modes of coupled nonlinear self-excited oscillators under selected resonance conditions. Due to nonlinear damping, producing self-excitation, the vibrations modes are strongly dependent both, displacement (amplitude) and velocity. Therefore the linear decoupling procedure cannot be applied for receiving proper solutions of the system. Moreover if the self-excited oscillators are driven by parametric or external excitations then their response can be periodic, quasi-periodic or chaotic. For the one degree of freedom system the regions of different vibration types can be found directly by analytical or numerical methods. The problem arises if the model has many degrees of freedom. For nonlinear systems the Linear Normal Modes can be used by making assumption that the model is weakly nonlinear. However, for strong nonlinearities that approach leads to results which are far from dynamics of the original system. For driven parametrically and self-excited systems two possible vibrations modes may appear: (a) resonant modes, inside the parametric resonance region where single frequency response takes place, (b) non-resonant modes, manifested by quasi-periodic response. Analysis of the resonant modes has been presented in the papers [2]-[5] while the nonlinear modes of coupled self-excited oscillators (autonomous model) without internal resonance condition have been investigated in [6]. Despite strong nonlinear damping, the systems motion has been decoupled successfully into two independent modal self-excited oscillators by the centre manifold reduction [7]. The present paper is a continuation of the former analysis. The nonlinear normal modes of coupled self-excited oscillators under internal resonance conditions are investigated. The method of Nonliner Normal Modes and modal surfaces formulation, as well as, the stability analysis of the received modal response for a wide parameters range are presented.
Flávio Faria, UNESP - Universidade Estadual Paulista, Brazil - Geraldo Silva, Universidade Estadual Paulista, Brazil - Vilma Oliveira, Universidade de São Paulo, Brazil.
Abstract. A fuzzy Lyapunov function approach for stability analysis of continuous-time Takagi-Sugeno fuzzy systems is proposed. The method is based on solution of Linear Matrix Inequalities, which can be efficiently solved by convex programming techniques, and can outperform other results available in the literature. Numerical examples illustrate the efficiency of the proposed method.
Marcus Silva, Universidade Federal do Pará, Brazil - Celso Bottura, Universidade Estadual de Campinas, Brazil.
Abstract. Nonlinear systems with time-varying uncertainties with known norm bound and exogenous disturbances are investigated in this work. Conditions for the determination of the H-infinity norm of this class of systems are obtained in the form of a convex optimization problem in terms of LMIs. It is also proposed a H-infinity optimal control design that aims to stabilize a class of nonlinear systems with time-varying uncertainties with known norm bound and exogenous disturbances and minimize its H-infinity norm. The optimal gain matrix is obtained by solving a convex optimization problem in terms of LMIs such as its H-infinity norm is minimized. Numerical examples are proposed for both methods.
Alfredo Bonini, Dilson Alves, UNESP, Brazil.
Abstract. Os métodos de fluxo de carga continuado são utilizados nos estudos de estabilidade estática de tensão. Neste trabalho investiga-se a influência de atualizar a matriz Jacobiana somente quando o sistema sofrer mudança significativa, ao invés de atualizá-la a cada iteração. Os resultados mostram uma redução do tempo computacional no traçado da curva P-V.
Elisabete Magalhães, Alfredo Bonini, Dilson Alves, UNESP, Brazil.
Abstract. Este trabalho propõe o método da continuação nas versões desacopladas de Newton. Na parametrização é utilizada a equação de reta localizada no plano formado pelas variáveis magnitude de tensão nodal e fator de carregamento. Os objetivos são traçar a curva P-V e obter o ponto de máximo carregamento.
Naryanne Peraro, UNESP, Brazil.
Abstract. The objective of this paper is analyze the influence of the action of transformers with variable transformation ratio specially Phase Shifter Transformer (TCPS) upon the interactions between machines in multimachine power system. The loads are considered as constant admittances, so the network is reduced to the generators internal busses, preserving the TCPS effects. The TCPS effects upon synchronizing capability is analyzed through admittances busses matrix, emphasizing transfer admittances between machines.
Biswa Nath Datta, Northern Illinois University, USA.
Abstract. The use of active feedback control strategy is a natural way to stabilize and control dangerous vibrations in structures, such as bridges, highways, buildings, and space and air crafts. These structures sometimes experience such vibrations due to resonance, when acted upon by external forces like gusty winds, earthquake or weight of human bodies. Indeed, several high rise buildings in Japan, a country prone to earthquakes, have been built with active controllers. Active controllers have also been and are being increasingly used in the constructions of buildings, bridges, and towers in other countries in the world as well, notably in Taiwan and Malaysia. These structures are distributed-parameter systems. However, because of practical considerations, such a system is very often discretized into a system of matrix second-order differential equations using finite-element techniques; control is then designed and implemented on this discretized system and finally applied to a real-life structure. Unfortunately, the existing vibrations control techniques, even for these simplified models, are fraught with numerical difficulties and engineering limitations. The vibration industries have approached vibration control problems in an ad hoc way and many of the difficulties of today’s industrial base in many countries stem from competing with high-tech companies in Japan and Europe who tend to take a more serious, mathematical approach to engineering problems. In the last few years, the speaker and his collaborators have developed a practical computational approach for feedback control in finite element structures. The distinctive features of this approach are (i) control can be designed directly on finite model without requiring transformation to a standard first-order state-space form, (ii) the algorithms require knowledge of only a small number of eigenvalues and eigenvectors of the associated quadratic matrix pencil which are all that can be computed with the state-of-the-art computational techniques and associated software packages, such as NASTRAN, and ANSYS, and, (iii) above all, no priori reduction of the order of the model or controller is required, no matter how large the problem is. This approach has also been successfully applied to another related industrial problem, namely, the finite-element model updating problem (FEMUP). FEMUP concerns with updating in a faulty and noise-corrupted finite element model using a few measured data from a real-life structure so that the updated model can reproduce the measured data accurately and the important physical and structural properties of the original model, such as the symmetry, positive definiteness, bandness, and connectivity, etc., remain preserved. If the model has been updated in this way, then the engineer can use the updated model in confidence for future design and constructions. The model updating has also useful applications in detecting damages, and monitoring health of structures after the structures experience natural disasters, such as earthquakes, hurricanes, and others. The minimal computational and engineering requirements of this new approach make it readily applicable to feedback control design and model updating in even very large practicallife structures. In this talk, these recent advances will be reviewed and a brief discussion will be presented on future directions of research in this area. The talk is of interdisciplinary in nature and will be of interests to engineers, mathematicians, and computational scientists.
Katica (Stevanovic) Hedrih, Mathematical Institute SANU Belgrade, Serbia, Servia.
Abstract. Discontinuities of kinetic parameter properties in dynamics of mechanical systems are listed as a source of strong non-linearity and considered. A group of the discontinuities of kinetic parameter properties are identified in the system with no ideal constraints caused by Admonton-Coulomb type friction. By using examples of the heavy mass particle motion along rough curvilinear lines (circle, cycloid, parabola, ellipse, arbitrary curvilinear line) in vertical plane, by derived corresponding differential double equations and corresponding equations of the phase trajectories, series of the discontinuities of system kinetic parameter properties are identified. Alternations in the equilibrium positions of the vibrations of the heavy mass particle motion along rough lines depending of direction motion followed by alternation of the friction force directions are discontinuities in the considered system dynamics. Some research results of fascinating non-linear dynamics of a heavy mass particle along rough rotate circles with Coulombs type friction are presented. Also, for the case that circle rotate around an axis, the differential double equation is derived and analyzed in the particular cases in the phase plane. Two types of triggers of coupled singularities, as well as coupled sub-triggers of coupled singularities in the non-linear dynamics of coupled rotors with no ideal constraints are identified.
Valeriano de Oliveira, Universidade Federal de Uberlândia, Brazil - Geraldo Silva, Universidade Estadual Paulista, Brazil.
Abstract. The main purpose of this work is to show that the class of MP-pseudoinvex nonsmooth optimal control problems is the largest class of problems where every process which satisfies the maximum principle is an optimal process. Such class of problems were introduced in [V.A. de Oliveira, G.N. Silva and M.A. Rojas-Medar, A Class of Multiobjective Control Problems, Optim. Control Appl. Meth., Vol. 30, pp. 77-86, 2009] for smooth problems.
José Sartorelli, USP, Brazil.
Abstract. We established the stability regions of the four fixed points of a double pendulum in the parameter space a vs. f, where a and f are the amplitude and the frequency of the vertical external forcing. We have observed Hopf bifurcations (super and subcritical), boundary crises or blue sky catastrophes. The experimental data were discussed considering high and low damping due to the viscous friction.
Dailhane Bassinello, Univesidade Estadual Paulista Campus Bauru, Brazil - José Balthazar, UNESP, Brazil - Bento R. de Pontes Junior, UNESP - Universidade Estadual Paulista, Brazil - Angelo Tusset, UFPR, Brazil.
Abstract. Neste trabalho é analisada a dinâmica de um sistema eletromecânico, em escola micro. O sistema considera duas placas fixas e uma placa móvel entre elas, a qual é aplicada uma tensão V (t), tais placas têm as funções de fornecer eletrodos para formar um capacitor ou armazenamento de energia elétrica, e fornecer elasticidade ou rigidez mecânica. Os resultados são obtidos através de simulações e integrações numéricas. Para os parâmetros utilizados foi possível observar comportamentos não desejáveis. Através da aplicação da teoria do controle ótimo foi possível projetar o controle e levar o sistema a uma orbita periódica desejada.
Atila Bueno, Universidade Estadual Paulista, Brazil - José Balthazar, UNESP, Brazil - José Roberto Castilho Piqueira, USP, Brazil.
Abstract. The Atomic Force Microscope introduced the surface investigation with true atomic resolution. In the dynamic mode of operation both amplitude and frequency modulation methods can be implemented by using Phase-Locked Loops. Here it is shown that Phase-Locked Loops can improve the perfomance of the Atomic Force Microscope providing the feedback signal to control both the amplitude and the oscillation frequency of the cantilever. It is also presented a method to design stable third-order Phase-Locked Loops.
Manuel Martín Pérez Reimbold, Universidade Regional do Noroeste do Estado do Rio Grande do Sul, Brazil - Mauricio de Campos, UNIJUI, Brazil - Marcos Ketzer, Universidade Regional do Noroeste do Estado do Rio Grande do Sul - UNIJUI, Brazil - Camila Seibel Gehrke, Universidade Federal de Campina Grande, Brazil.
Abstract. This paper discusses, by estimation, to obtain the nuclei characteristic parameters of MEMS micro-rotors. Mass, damping, and elasticity coefficient are obtained by ARX model and the estimators batch: LS and IV. The results motivate to apply other models available in discrete parametric system identification.
Jorge Felix, UNIJUI, Brazil.
Abstract. This paper presents the dynamical behavior of an optimal controller for a piezoceramic bar transducer and non-ideal generator system. Furthermore, for a non-ideal linear structure (NIS) coupled to a nonlinear energy sinks (NES). The uncontrolled and controlled models are numerically simulated using ode45 of MATLAB. Linear Quadratic Regulator (LQR) technique is used to design a state feedback controller. The LQR control scheme consists of using a full state feedback controller of the form u=-Kcx, where Kc is a control gain matrix. The goal is to use LQR technique to suppress the limit cycle oscillations and chaotic oscillations of the system and to maintain stability of the closed loop system.
Angelo Tusset, UTFPR, Brazil - José Balthazar, UNESP, Brazil.
Abstract. Em microscópia de força atômica (AFM), a análise do comportamento do microcantilever vibrando, de suas não linearidades e da interação não-linear entre o tip e a amostra pode ter grande influência na compreensão da dinâmica do cantilever. Neste trabalho, é analisada a dinâmica não-linear e o comportamento caótico para o caso da (AFM) no modo intermitente (tapping) considerando os efeitos do amortecimento em um meio hidrodinâmico. Os resultados obtidos através e simulações computacionais indicaram a ocorrência de movimentos caóticos. Com o objetivo de controlar o sistema em uma orbita desejada foi proposto um controle considerando a técnica do controle linear feedback.
Ricardo Nozaki, UNESP - São Paulo State University, Brazil - José Balthazar, UNESP, Brazil - Angelo Tusset, UTFPR, Brazil - Bento R. de Pontes Junior, UNESP - Universidade Estadual Paulista, Brazil.
Abstract. The atomic force microscope system has become a popular and useful instrument to measure the intermolecular forces, with atomic-resolution that can be applied in electronics, biological analysis, materials, semiconductors etc. This paper studies the complex nonlinear dynamic behavior of the probe tip between the sample and cantilever of an atomic force microscope using numerical simulations, method of multiple scales, and optimal linear control.
Fábio Chavarette, Universidade Estadual Paulista "Julio de Mesquita Filho", Brazil - Ivan Guilherme, UNESP, Brazil - Orlando Saraiva, Uniararas, Brazil - Nelson Peruzzi, UNESP Jaboticabal, Brazil.
Abstract. This paper presents the particle swarm optimization approach for reducing the oscillatory movement of the micro-electro-mechanical systems to periodic orbits. We analyze the non-linear dynamics in an oscillator micro-electro-mechanical and demonstrated that this model has a chaotic behavior. Chaos control problems consist of attempts to stabilize a chaotic system to an equilibrium point, a periodic orbit, or more general, about a given reference trajectory. This approaches is applied in analyzes the nonlinear dynamics in an oscillator mechanical MEM. The simulation results show the identification by particle swarm optimization is very effective.
Fábio Campos, UFRJ, Brazil - Armando Carlos Pina Filho, Universidade Federal do Rio de Janeiro, Brazil - Aloísio de Pina, Federal University of Rio de Janeiro, Brazil.
Abstract. Robot manipulators can be applied to material removal processes, presenting advantages as compared with CNC machine tools, such as: more flexibility, lower initial cost, lesser waste of material, and better surface finishing on the parts. The objective of this work is present a study about robots used to material removal applications.
Thiago Ferreira, UFRJ, Brazil - Armando Carlos Pina Filho, Universidade Federal do Rio de Janeiro, Brazil - Aloísio de Pina, Federal University of Rio de Janeiro, Brazil.
Abstract. The main purpose of this work is present the modeling of a hexapod robot using the software AutoCAD, as well as the main characteristics of this type of robot, which represents a typical mobile robot and a useful mechanism for diverse tasks.
Jean Paulo dos S. Carvalho, Rodolpho Vilhena de Moraes, UNESP/FEG, Brazil - Antonio Prado, INPE, Brazil.
Abstract. Low-altitude, near-polar orbits are very desirable as science orbits for missions to planetary satellites, such as Earth''s Moon. In this paper we present an analytical theory with numerical simulations to study the orbital motion of lunar low altitude artificial satellite. We consider the problem of an artificial satellite perturbed by the non-uniform distribution of mass of the Moon. The conditions to get frozen orbits are presented. Using an approach with the simple-averaged problem, we found families of periodic orbits for the problem of an orbiter around the moon, where frozen orbits valid for long periods of time are found. A comparison between the models for zonal and tesseral harmonics coefficients is presented.
Alan Zanatta, University of São Paulo, Brazil, Eduardo Godoy, São Carlos School of Engineering - University of São Paulo, Brazil, Arthur José Vieira Porto, USP - São Carlos, Brazil.
Abstract. Sistemas de controle via redes (NCS Networked Control Systems) representam um recente paradigma na pesquisa de sistemas distribuídos com redes industriais. Este trabalho apresenta o desenvolvimento de um NCS via rede CAN (Controller Area Network) para controle de posição de motores DC focando nas tarefas de simulação, análise e controle. Resultados obtidos comprovam a viabilidade de aplicação de NCS com redes CAN, fornecendo informações sobre sua implementação e validando a utilização da ferramenta TrueTime em seu projeto.
Yuri Mota, UFRJ, Brazil, Armando Carlos Pina Filho, Universidade Federal do Rio de Janeiro, Brazil, Aloísio de Pina, Federal University of Rio de Janeiro, Brazil.
Abstract. Bipedal robots represent a important research subject, and there are several types of robots, such as: WABIAN-2R, QRIO, ASIMO, REEM-B, Toyota Walking, Toyota iFoot and HPR-2. In this work some characteristics of these robots will be presented, intending to evaluate the benefits for society, from the insertion of robots in urban environment.
Camila Gonsalez, Universidade estadual Paulista, Brazil, Vitor Franco, USP - São Carlos, Brazil, Michael Brennan, University of Southampton, Great Britain, Samuel da Silva, Universidade Estadual do Oeste do Paraná, Brazil, Vicente Lopes Junior, Universidade Estadual Paulista UNESP Departamento de Engenharia Mecânica, Brazil.
Abstract. Nowadays, a major concern is the need to develop new energy sources. In this context, a sector that has attracted much interest is one in which devices that are able convert other types of energy into electrical energy. This technique is known as Energy Harvesting and consists of energy capture and storage from ambient sources. This paper works with piezoelectric and electromagnetic transducers, which are able to convert mechanical vibrations into electrical energy. However, when an electrical circuit is coupled to the transducer the mechanical system is strongly influenced by it. This paper presents a model that considers the coupling influence between these systems. The structure modeled as a free sliding beam with one electrical load. A program was developed to analyze the behavior of this system, as well as the optimal conditions for power harvested.
Fernando Zago, UNIJUÍ, Brazil, Marat Rafikov, UFABC, Brazil, Antonio Valdiero, UNIJUÍ, Brazil, Luiz Rasia, UNIJUI, Brazil.
Abstract. Este trabalho trata do controle ótimo em um quarto do sistema de suspensão automotiva. É possível ajustar o modo de controle da suspensão, que pode privilegiar o conforto dos ocupantes ou uma condução mais esportiva. Apresentam-se os resultados de simulação para uma bancada de validação experimental a ser construída.
Ana Klinke, universidade estadual paulista - júlio de mesquita filho, Brazil, José Manoel Balthazar, UNESP: Univ Estadual Paulista, Department of Statistics Applied Mathematics and Computation, PO Box , Brazil, Jorge Felix, UNIJUI, Brazil, Fábio Roberto Chavarette, UNESP: Univ Estadual Paulista, Department of Mathematics, Ilha Soltlteira, Brazil, Algeria.
Abstract. The technology of micro-electro-mechanical systems has many applications on Engineering Sciences. However, the design of such mechanical systems can be quite challenging due to nonlinear effects, which may strongly affected the dynamics behavior. The physical model studied is a micro-electro-mechanical coupling with an electrodynamic shaker, by using numerical simulations.
Luciano C. M. Andrade, Rogério Flauzino, University of São Paulo, Brazil, Ivan Nunes da Silva, USP, Brazil.
Abstract. O propósito desse trabalho é realizar previsão de demanda de energia elétrica no curtíssimo prazo baseado em sistemas fuzzy. O MAPE obtido foi de 2,24% e de 1,35% para medidas coletadas em subestações de Mogi-Guaçu e Votuporanga, respectivamente. Tais resultados demonstram o bom desempenho do sistema de inferência fuzzy empregado.
José Roberto Campos, UNESP - Campus de Ilha Solteira, Brazil, Anna Diva Lotufo, UNESP- Campus of Ilha Solteira, Brazil, Carlos Minussi, UNESP - Universidade Estadual Paulista, Brazil, Mara Lopes, UNESP, Brazil.
Abstract. This work develops a feedforward neural network by backpropagation algorithm emphasizing the JAVA language. To illustrate the proposed methodology is used an example with data from a Multi Machine Electrical Power System Transient Stability Analysis aiming to provide an efficient diagnosis.
André Nunes de Souza, UNESP, Brazil, Lucas Imaizumi Pereira, Maria G. Zago, Universidade Estadual Paulista, Brazil, Pedro da Costa Jr., FEB, UNESP - Univ Estadual Paulista, Brazil, João Paulo Papa, Danilo Sinkiti Gastaldello, Universidade Estadual Paulista, Brazil.
Abstract. A evolução tecnológica propiciou a maior utilização de equipamentos eletrônicos, essas cargas nãolineares são fontes de distorções harmônicas e, também, são dispositivos mais sensíveis na rede elétrica. Este artigo integra elementos da Inteligência Computacional com ensaios experimentais, visando identificar os efeitos e as causas das interferências nas medições de energia.
Gabriel Vendramini, Paulo Silva, Universidade Estadual Paulista, Brazil.
Abstract. O sistema de um pêndulo invertido, por apresentar características dinâmicas intrinsecamente instáveis, tem sido estudado como planta alvo para avaliar o desempenho de diferentes técnicas de controle. O presente trabalho apresenta a modelagem, a simulação e o controle de um sistema composto de um pêndulo invertido sobre uma plataforma móvel descrevendo trajetória unidimensional, em que o objetivo consiste em controlar duas variáveis simultaneamente: o deslocamento angular do pêndulo e o deslocamento linear da plataforma. Para isso, utiliza-se técnicas clássicas e desenvolve-se um controle inteligente adaptativo, chamado MFA (Model-Free Adaptive).
Manoel Aguiar , Vilma Oliveira, Alessandro Locatti, César Domingues, Universidade de Sao Paulo, Brazil.
Abstract. Neste trabalho, material didático para o projeto e a implementação em tempo real de controladores a partir de modelos Simulink para ser utilizado em disciplinas básicas de laboratório de controle é fornecido. A praticidade do ambiente de implementação de controladores digitais com o Simulink para ensinar controle realimentado é demonstrada. A ênfase é dada na conexão da planta a ser controlada com o modelo Simulink. O experimento com uma planta real é adequado para ser dado no 3o. ano de cursos de engenharia auxiliando o aluno a compreender os componentes de hardware e software de um sistema de controle realimentado. Um motor de corrente contínua (CC) juntamente com um tacogerador como transdutor comumente encontrados em laboratórios de graduação são usados para ilustrar o ambiente de implementação
Ivan Guilherme, UNESP, Brazil, Jonas Queiroz, Paulo Henrique Arantes Urgal, UNESP, Brazil, Fábio Chavarette, Universidade Estadual Paulista "Julio de Mesquita Filho", Brazil.
Abstract. Durante a perfuração de um poço de Petróleo podem ocorrer diversas anormalidades. Neste trabalho é apresentada uma arquitetura de referência para dar suporte ao desenvolvimento de Sistemas Inteligentes Web, visando a implementação de métodos para a analise dos dados gerados durante a perfuração de poços de petróleo. A arquitetura proposta é baseada na arquitetura orientada a serviços (SOA). Baseado na arquitetura de referência proposta é apresentado um Sistema Inteligente Web para a identificação anormalidade Packer Hidráulico. O método de análise implementado na aplicação é a Redes Neurais Perceptron Multi-Camadas.
Martin Dill, Sérgio Dill, Edson Padoin, Paulo Sausen, Mauricio de Campos, Universidade Regional do Noroeste do Estado do RGS (UNIJUÍ)
Eduardo Altmann, Universidade Federal do Rio Grande do Sul, Brazil.
Abstract. Billiards are paradigmatic examples of dynamical systems and serve as prototypes of mechanical, optical, and accoustical systems. Recent experiments and applications have shown the importance of considering open billiards, in which case trajectories can leave the system and therefore be detected. Openess in dynamical systems raises important theoretical questions that will be broadly discussed in this talk. The main specific application reported in the talk will be to optical dielectric billiards. In this case the light rays leave the billiard through refraction at the boundary (according to Fresnel''s laws). A very rich dynamics typically exists in such billiards due to the generic coexistence of regular and chaotic trajectories. The transient chaos theory will be adapted and expanded to describe such non- hyperbolic partially opened systems. We will use this theory to interpret previous results and new numerical simulations (on the annular billard). In particular, we will see why the decay of energy changes dramatically over time (from exponential to power-law), but the far-field emission changes only slightly
Alireza Ture Savadkoohi, École Nationale des Travaux Publics de l'État (ENTPE), France, Leonid I. Manevitch, N.N.Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4, Kosygina Street, 119991, Russia, Claude Henri Lamarque, Université de Lyon, École Nationale des Travaux Publics de lÉtat, DGCB, FRE CNRS 3237, 3 Rue Maur, France.
Abstract. In this paper we consider two coupled oscillators exhibiting both transient chaos and energy transfer from a master linear degree of freedom to a slave nonlinear energy sink. The Melnikov integral is endowed in order to study the possibility of existence of chaos and transversal homoclinic orbits and their control in a dynamical system. Then, the complexification method as an alternative to nonlinear normal modes is implemented to reveal the behavior of the system during the energy exchange between two oscillators.
Miguel A. F. Sanjuán, Department of Physics, Universidad Rey Juan Carlo,Spain.
Abstract. When we attempt to control a linear system in which some noise has been added, typically we need a control higher or equal to the amount of noise added. When we have a region in phase space where there is a chaotic saddle, all initial conditions will escape from it after a transient with the exception of a set of points of zero Lebesgue measure. The action of an external noise makes all trajectories escape even faster. Attempting to avoid those escapes by applying a control smaller than noise seems to be an impossible task. Here we show, however, that this goal is indeed possible, based on a geometrical property found typically in this situation: the existence of a horseshoe. The horseshoe implies that there exists what we call safe sets, which assures that there is a general strategy that allows one to keep trajectories inside that region with a control smaller than noise. We call this type of control partial control of chaos [1,2] that allows one to keep the trajectories of a dynamical system close to the saddle even in presence of a noise stronger than the applied control. In this talk recent progress and new results on this control strategy are presented. This is joint work with James A Yorke (USA) and Samuel Zambrano (Spain).[1] Samuel Zambrano, Miguel A. F. Sanjuán, and James A. Yorke. Partial Control of Chaotic Systems. Phys. Rev. E 77, 055201(R) (2008).[2] Samuel Zambrano and Miguel A. F. Sanjuán. Exploring Partial Control of Chaotic Systems. Phys. Rev. E 79, 026217 (2009).
José Rodrigues, Universidade Estadual Paulista/Faculdade de Engenharia de Bauru, Brazil.
Abstract. O artigo aborda o desenvolvimento das equações gerais das ondas de propagação de tensão e corrente elétrica ao longo dos tradicionais e reais sistemas de transmissão de energia elétrica, que através dos modelos matemáticos utilizados na engenharia elétrica e das condições de contorno inerentes ao estudo, culmina em um sistema de equações diferenciais ordinárias de segunda ordem. A solução desse sistema é de conhecimento clássico na literatura, porém, para a situação em particular dos sistemas de transmissão de energia elétrica, foi possível propor uma metodologia de resolução não usualmente aplicada, mas satisfatória e suficientemente precisa para o objetivo em análise se tratando da aplicação de série de potência, em particular a série de Maclaurin, na solução das equações diferenciais ordinárias. A análise efetuada e os resultados encontrados são apresentados no corpo do artigo e demonstram que satisfazem integralmente sua utilização em fenômenos desse porte em linhas de transmissão.
Eduardo Rodrigues, UNESP - Univ Estadual Paulista, Brazil, Osvaldo Manzoli, UNESP - Univ Estadual Paulista, Brazil.
Abstract. No presente trabalho desenvolve-se um modelo constitutivo baseado na mecânica do dano contínuo para representar o comportamento de materiais que apresentam diferentes respostas quando solicitados à tração ou à compressão. O modelo é apto para representar a formação de descontinuidades no campo de deslocamento em materiais quase-frágeis.
Cristiano Agostini, Universidade Estadual Paulista, Brazil.
Abstract. The work consists on the vibration analysis of vertical rotors in gravitational and gyroscopic effects. Forward and backward modes are obtained separately through the implementation in MATLAB of complex modal analysis in conjunction with the finite elements method. Numerical simulations have been satisfactory when compared with the existing literature.
F.C. Malange, Universidade Estadual Paulista Julio de Mesquita Filho - UNESP, Brazil, Dilson Alves, UNESP, Brazil.
Abstract. This paper presents an alternative approach to real power loss reduction and loading margin increase by using continuation method. The results show that this procedure leads to an increase in the maximum loading point and an improvement in the static voltage stability margin. In addition, it also leads to an improvement in the voltage profile.
Marcos Ketzer, Universidade Regional do Noroeste do Estado do Rio Grande do Sul - UNIJUI, Brazil, Mauricio de Campos, UNIJUI, Brazil, Manuel Martín Pérez Reimbold, Universidade Regional do Noroeste do Estado do Rio Grande do Sul, Brazil, Edson Padoin, Unijuí, Brazil.
Abstract. This paper reviews the methods of SVPWM (Space Vector Pulse Width Modulation) and studies its extension to other configurations of inverters. The space vector algorithm is worked on three topologies: 3-arms and 4-wires, 4-level multilevel inverter and four arms. The algorithms and the new proposals are implemented and validated on the software SIMULINK ®, demonstrating a low THD in the modulated signals.
Gláucia Silvestre Claro, Unesp-Universidade Estadual Paulista- Bauru, Brazil, Osvaldo Manzoli, Unesp - Univ Estadual Paulista, Brazil, Eduardo Rodrigues, unesp - Univ Estadual Paulista, Brazil.
Abstract. Para representar discretamente o aparecimento e a propagação de descontinuidades em meios inicialmente contínuos, sem a necessidade de alteração geométrica da malha de elementos finitos, faz-se necessário conhecer a posição da superfície potencial de falha no interior de cada elemento finito. O presente trabalho contribui para a generalização dos estudos numéricos de problemas de formação e propagação de fraturas, mediante a formulação de elementos finitos com descontinuidades incorporadas, desenvolvida por Manzoli e Shing (2006), [1], para problemas bidimensionais. Nos problemas planos as falhas correspondem a linhas, que podem ser construídas de maneira relativamente simples, por meio de sequenciamento de segmentos retos orientados de acordo com a direção de falha, no interior de cada elemento do sólido. Já na análise tridimensional devem-se construir superfícies de falha constituídas por superfícies planas no interior de cada elemento finito, principalmente pelo fato de que essas superfícies devem ser contínuas entre os elementos. No presente trabalho apresenta-se uma técnica para a construção da superfície de falha em problemas tridimensionai. Essa técnica é baseada na solução de um problema térmico equivalente, estabelecido através das direções da superfície fornecida pelo critério de falha. Tais informações provêm do estado de tensões da solução do problema mecânico, que, por sua vez, é afetado pelas superfícies de falha construídas pelo problema térmico equivalente. A solução do problema térmico equivalente por elementos finitos é realizada mediante as mesmas discretização e interpolações do problema mecânico. A validação ocorre através de simulações tridimensionais de problemas básicos e de ensaios experimentais de fratura existentes na literatura, contrastando os resultados encontrados numericamente com os experimentais.
Marcelo Valentini, UFPR, Brazil, Roberto Machado, Mildred Hecke, Adriano Scremin, Ufpr, Brazil.
Abstract. A brief review on the use of meshfree methods focusing its difficulties across time is presented. MaxEnt basis functions formulation and aspects are seen with its advantages on mechanical applications. The results are 1D and 2D MaxEnt basis functions with several prior and particle distributions to illustrate the great potential of the method.
Cássio Belusso, Universidade Regional do Noroeste do Estado do Rio Grande do Sul - UNIJUÍ, Brazil, Cíntia Doico, Universidade Regional do Noroeste do Rio Grande do Sul, Brazil, Jorge Felix, UNIJUI, Brazil, José Balthazar, UNESP, Brazil.
Abstract. Neste trabalho mostra-se a análise dinâmica não-linear de um pulverizador torre com suspensão veicular. O sistema é representado por equações diferenciais ordinárias de segunda ordem não-lineares com três graus de liberdade. As simulações numéricas foram realizadas no software MATLAB, em ode45. Verificou-se uma grande influência da rigidez da junção torsional nos deslocamentos angulares da carreta e da torre e no deslocamento vertical da carreta. Encontrou-se um movimento caótico do sistema devido às crescentes frequências de excitação harmônica na suspensão veicular.
Zvi Artstein, The Weizmann Institute of Science, Israel.
Abstract. We review the modeling and analysis of coupled fast and slow dynamical systems including dynamics depicted by differential equations and by control systems. We introduce, in particular, a novel approach, aiming at relaxing some classical assumptions. The techniques employed by the new approach utilize evolution of probability distributions each forms an invariant measure of the dynamics. Some examples and relevant references are displayed. The presentation will start with a general introduction to Young Measures and their role as a variational limit of highly oscillatory solutions.
Oleg Gendelman, Tamir Bar, Technion - Israel Institute of Technology, Israel.
Abstract. The paper investigates regimes of self excitation in oscillatory systems with attached nonlinear energy sink (NES). For the simple example of primary Van der Pol oscillator, the initial equations are reduced by averaging to 3D system. Small relative mass of the NES justifies analysis of this averaged system as singularly perturbed with two "slow" and one "super slow" variable. Such approach, in turn, provides complete analytic description of possible response regimes. In addition to almost unperturbed limit cycle oscillations (LCOs), the system can exhibit complete elimination of the self excitation, small amplitude LCOs as well as excitation of quasiperiodic strongly modulated response (SMR). In the space of parameters, the latter can be approached by three distinct bifurcation mechanisms: canard explosion, Shil''nikov bifurcation and heteroclinic bifurcation. Some of the above oscillatory regimes can co exist for the same values of the system parameters. In this case, it is possible to establish the basins of attraction for the co-existing regimes. Direct numeric simulations demonstrate good coincidence with the analytic predictions. More complicated primary systems with internal resonance can give rise to more complicated self excited responses, including chaotic modulation of the primary frequency.
Marcio Dantas, Universidade Federal de Uberlãndia, Brazil.
Abstract. In this paper we get some results about the dynamics of a class of mechanical systems under strong dissipation. We show the existence of unstable hyperbolic periodic orbits as well as the existence of quenching for a mechanical system.
Masayoshi Tsuchida, Sao Paulo State University, Brazil.
Abstract. Usually the separation of gas particles becomes an expensive process. In this paper we present a procedure of confinement of charged particles using a time dependent magnetic field. We consider a main magnetic and a transversal periodic magnetic field with controllable frequency. Adjusting this frequency, the well known resonance effect captures the particles that have the same frequency.
Antonio Batista, Carlos Batista, Universidade Estadual de Ponta Grossa, Brazil, Ricardo Viana, Sergio Lopes, Universidade Federal do Parana, Brazil, Tiago Silva, Universidade Federal do ABC, Brazil.
Abstract. Neuron activity presents two timescales, a fast one related to action potential spiking, and a slow timescale in which bursting takes place. Some pathological conditions are related with the synchronization of the bursting activity in a weak sense, meaning the adjustment of the bursting phase due to coupling. We investigated coupled Rulkov maps network with randomly distributed parameters, and exhibiting the small-world property. The clustered network exhibits collective oscillations in the form of synchronized bursting rhythms, without affecting the fast timescale dynamics. We analyzed global synchronization varying the probabilities of intracluster and intercluster connections. Numerical experiments appeared to have the same outcomes as analytical predictions. Besides, analysis of the distribution of the time of global synchronization showed a intermittent behaviour that is observed in epileptic activity.
Marcelo Greco, Ivone Ferreira, Felíco Bruzzi Barros, Júnia Stief, Federal University of Minas Gerais, Brazil.
Abstract. This paper investigates geometric nonlinear dynamic response of a telecommunication tower. The geometric nonlinearity is addressed by using a formulation called Positional and the equilibrium equations derived are discretizated in time, with the aid of time integration algorithms, one explicit and other one implicit. The numerical results demonstrate the efficiency proposed procedure.
Tiago Kroetz, Filipe Leôncio Braga, ITA Departamento de Física, Brazil, Renata Mourão, Marisa Roberto, ITA, Brazil, Iberê Luis Caldas, USP Instituto de Física, Brazil.
Abstract. We propose a simple model to reproduce single-null magnetic surfaces with specific choices of: X-point position, triangularity, elongation and magnetic axis. The model is composed by a set of parallel infinite wires conducting electric currents. The topology of magnetic surfaces depends on the position and the electric current values of each wire as a whole. Although this divertor model is not appropriate to represent the plasma core, it describes the magnetic field lines dynamics close to the separatrix. We use a set of five wires to reproduce magnetic surfaces topology similar to the ITER one. Furthermore, we consider the perturbation introduced by typical resonant error field to investigate the stochastic layer formation near the separatrix.
Francisco Marcus, USP, Brazil.
Abstract. For tokamak models using simplified geometries, we have numerically investigated how the onset of Lagrangian chaos at the plasma edge could be confined for specific value of the radial wave number. Using a two waves Hamiltonian model, we present the conditions to use the Robust Tori surface to reduce the particle radial transport.
Elvidio Gavassoni, Paulo Gonçalves, Deane Roehl, Rio de Janeiro Catholic University, Brazil.
Abstract. The nonlinear normal model (NNM) concept is applied to analyze the dynamical behavior of a guyed tower. The model used is a 3D rigid link restrained by three inclined extensional springs. NNMs are obtained by the asymptotical method and the results show important NNM features like instability and multiplicity of modes.
Maria do Rosario de Pinho, University of Porto, Portugal.
Abstract. Here we consider free time optimal control problems involving mixed state-control constraints. For such problems we derive necessary conditions of optimality in the form of a Maximum Principle appealing to recent results on mixed constraints where necessary conditions in the form of a nonsmooth maximum principles are derevied under minimal regularity assumptions. Applications to optimal control problems involving differential algebraic equations are also considered.
Oleg Makarenkov, Imperial College London, Great Britain.
Abstract. This research addresses occurence of resonance solutions in mechanical oscillators with elastic and impact obstacles. The unperturbed system will be hamiltonian (or linear) with a family of cycles crossing (or touching) the obstacle. Classical averaging principle says that nonautonomous perturbations destroy this family resulting in asymptotically stable resonance oscillations. I will discuss the influence of the obstacle on the conclusions available over the averaging principle.
A. Mineto, M. Souza Braun, H. Navarro, P. Varoto, USP - Universidade de São Paulo, Brazil.
Abstract. Piezoelectric materials have been found in several applications as transducers which are possible to harvest energy from vibrating structures. A simple transverse mode type piezoelectric generator model based on EulerBernoulli beam theory with the following assumptions is presented: (a) the piezoelectric layer thickness in comparison to the length of the beam is very thin and (b) the electrical field between the upper surface and lower surface of the piezoelectric layer is uniform. We applied this model to predict the power generated from a cantilever steel beam with harmonic oscillations using PZT-PIC 255. A parametric study is also performed to optimize the energy generation of piezoelectric-beam system.
Joao Marra, Instituto Tecnológico de Aeronáutica, Brazil, Luiz Carlos Sandoval Goes, Instituto Tecnologico de Aeronautica, Brazil, Paulo Gonçalves, EMBRAER, Brazil.
Abstract. O presente trabalho trata de um sistema MIMO de controle ativo de vibrações, que atua em banda larga de frequências a fim de reduzir os níveis vibratórios de uma estrutura aeronáutica (seção de fuselagem) sob excitação de ruído branco. A planta teve suas FRFs (Funções Resposta em Frequência) reconstituídas através da metodologia de autovalores e autovetores, cujos valores são provenientes de uma modelagem numérica (FEM). O algoritmo Fx-LMS (implementado com filtros FIR para 7 entradas e 6 saídas), apresentou reduções (médias) de 18dB. Os resultados reforçam a vertente do contole de ruído através do controle ativo das vibrações estruturais, técnica referenciada por ASAC
H. Navarro, USP - Universidade de São Paulo, Brazil, Luiz A. M. Gonçalves, EESC-USP, Brazil.
Abstract. This study involves the analysis of elastic-plastic-damage dynamics of one-dimensional structures comprising of periodic materials. These structures are composed by multilayer unit cells with different materials. The dynamical characteristics of the composite materials is analysed by wave propagation. The material models have a linear dependence for elasticity problems and non-linear for elastoplasticity-damage problems. This paper aims to simulate structure problems composed by periodic materials. This work brings a formulation of Galerkin method for one-dimensional elastic-plastic-damage problems. Time-stepping algorithm for non-linear dynamics is also presented. Numerical treatment of the constitutive models is developed by the use of return-mapping algorithm. For spatial discretization the standard finite element method is used. The procedure proposed in this work can be extended to multidimensional problems, analysis of strain localization, and for others material models.
Vander Prado, Universidade Estadual Paulista - Faculdade de Engenharia de Ilha Solteira, Brazil, Ricardo Tokio Higuti, Universidade Estadual Paulista - UNESP, Brazil.
Abstract. Ultrasonic techniques for nondestructive testing are extensively used in industry because of several aspects: do not produce changes in the inspected materials, simplicity and testing speed, high sensitivity and possibility to propagate in several types of media: solid, liquid and gaseous. In this work, some ultrasonic techniques for thickness measurement are implemented in hardware, using simulated and experimental signals. The processing is made on an FPGA (Spartan-3E, Xilinx), allowing fast processing and ease of programming. The algorithms implemented are conventional methods, such as peak and threshold detection, and also signal processing methods using cross-correlation and the Hilbert transform. Several characteristics are evaluated, such as signal center frequency, sampling frequency, signal-to-noise ratio, resolution (bits per sample in processing), which influence the measurement accuracy and implementation costs. The fixed-point results obtained with the FPGA are compared to floating-point results from MATLAB, using the same algorithms.
Arlindo Montagnoli, Federal University of Sao Carlos, Brazil.
Abstract. In this work mass-spring-damper technique was used in simulation of deformable models for use in virtual surgeries. Finite elements technique present more robust results but it is not appropriated for the use in real time simulations. The two techniques had been developed considerably in the last decade, in relation to the model of finite elements, the evolution basically was focused in the optimization of the algorithms for use in real time and the mass-spring technique evolves in the direction to be more efficient in relation the not elastic conditions of soft tissues. The main objective of study in mass-spring methods was focused in the choice of the adjusted model more adequate for the simulation in three dimensions of the larynx, more specifically of the vocal folds, therefore beyond the simulation of the surgery it is intended in future works to analyze the interaction fluid structure, in the case air flow proceeding from the lung to the vocal folds.
Frederico Silva, Federal University of Goiás, Brazil, Paulo Gonçalves, Rio de Janeiro Catholic University, Brazil, Zenon Del Prado, Federal University of Goiás, Brazil.
Abstract. This work investigates the nonlinear dynamic behavior and instabilities of partially fluid-filled cylindrical shell subjected to axial load. A discrete low-dimensional model for the nonlinear vibration analysis is derived to study the shell vibrations. The influence played by the height of the internal fluid on the nonlinear shell response is examined.
Angelo Luongo, Dept. of Structural Engineering, Università di L’Aquila, Italy.
Abstract. The Center Manifold Theory (CMT) and the Normal Form Theory (NFT) are the most widespread tools of Bifurcation analysis, since they display the true essence of the system dynamics around a non-hyperbolic equilibrium point. The former reduces the dimension of the system, the latter the complexity of the bifurcation equations. As an alternative, but less popular approach (sometimes looked as suspicious), the Multiple Scale Method (MSM) performs both operations simultaneously, thus revealing itself computationally more efficient; moreover, it furnishes equations in which the fast dynamics is filtered. In this talk, the basics of the CMT & NFT are reviewed, and some new algorithmic aspects of NFT illustrated. Then, the MSM is discussed, both for systems with diagonalizable and not-diagonalizable Jacobian matrix. Attention is focused on the strict, and may be hidden, relations existing between the two approach philosophies.
Nelson Peruzzi, UNESP Jaboticabal, Brazil, Fábio Chavarette, Universidade Estadual Paulista "Julio de Mesquita Filho", Brazil, Ivan Guilherme, UNESP, Brazil.
Abstract. Resumo: Sob certas condições do traçado e velocidade, o trator pode apresentar instabilidade e provocar vibrações que podem prejudicar os trabalhos no campo. Para compreender a dinâmica do trator no campo pode-se usar a modelagem matemática. Neste trabalho considerou-se um modelo matemático com excitação periódica externa e com dois graus de liberdade, obtido por [6], como o modelo do trator-campo. O objetivo foi analisar a dinâmica das vibrações de um trator durante o seu trabalho no campo. Nas simulações foram usados os parâmetros de controle: distância entre duas saliências consecutivas do solo e a velocidade do trator.
Sergio David, Universidade de São Paulo, Brazil.
Abstract. Abstract: A great number of researchers have studied and taught about non-linear phenomena exhibiting non-periodic and bounded solutions in several areas of science and engineering. However, in most cases, these concepts are not explored experimentally in order to facilitate thoroughly understanding of the student. In this paper we have examined the dynamical behaviour of an elastic wide plate induced by two electromagnets and submitted to external excitation. This study have technical applications but, in addition, the main goal is to serving as a convenient experimental platform model providing subsidies to understand better the non-linear and chaotic phenomena by undergraduate and graduate students .
Cleber Oliveira, State University of Londrina, Brazil, José Carlos Pizolato, State University of Londrina, Brazil
Abstract. Chaotic systems have been applied in data cryptography due to the random behavior obtained through algebraically simple functions. This paper aims to investigate the efficiency of Chuas chaotic system appliance in an algorithm of information cryptography. The results gained demonstrate that this cipher can be used in data cryptography.
Stefano Lenci, Laura Marcheggiani, Polytechnic University of Marche, Italy, Giuseppe Rega, Sapienza University of Rome, Italy.
Abstract. The problem of the practical stability of structures is addressed in a modern way by considering the effects of both static and dynamic perturbations. The major historical contributions, due to Euler, Koiter and Thompson, are reviewed and illustrated by a archetypal model permitting to highlights the main mechanical and dynamical points. It is found that a global approach is necessary for reliable safety estimation, especially in the neighborhoods of (static) critical loads. Considering that the admissible load threshold has to account for dynamical integrity concepts, the Koiter critical load must be lowered, obtaining the so called Thompson critical load. It is shown how these two threshold share some properties (e.g. both depends on imperfections in a sensitive way, which must be known for practical calculations), while having a deep different meaning: the former is related to static imperfections, and requires only a local analysis, while the latter is related to dynamical imperfections, and requires a global analysis. It is shown that pcr,Euler > pcr,Koiter > pcr,Thompson, i.e., that the advancement of knowledge leads to a lower estimation of the actual critical load.
Jeferson Cassiano, Federal University of ABC, Brazil.
Abstract. This paper study the exitence of closed orbits and the stability of the one. The main tool used is the first return application with the Poincaré''s section in discontinuity manifold.
Diogo Costa, Mário Silva, UNESP - Campus de Rio Claro, Brazil, Juliano de Oliveira, UNESP-IGCE, Brazil, Edson Denis Leonel, Universidade Estadual Paulista, Brazil.
Abstract. Some dynamical properties for a classical particle confined in an infinitely deep box of potential containing a periodically oscillating square well are studied. The dynamics of the system is described by a two dimensional non-linear area preserving mapping for the variables energy and time. The phase space is mixed and the chaotic sea is described using scaling arguments. Thus, critical exponents are obtained near a transition from integrability to non-integrability. The formalism is robust and can be extent to many different kinds of mappings.
Diego Orlando, Pontifícia Universidade Católica do Rio de Janeiro - PUC-Rio, Brazil, Paulo Gonçalves, Rio de Janeiro Catholic University, Brazil, Giuseppe Rega, Sapienza University of Rome, Italy, Stefano Lenci, Polytechnic University of Marche, Italy.
Abstract. Cable stayed structures are widely used to build towers, cover wide spans and in off-shore structures, among others. The prevention of buckling of these structures is a major concern in engineering design. In this paper the stability analysis of a simplified two-degree-of-freedom model of a guyed tower is studied. The results show that the system displays a strong modal coupling, leading to several unstable post-buckling solutions, thus leading to high imperfection sensitivity. For applied loads lower than the theoretical buckling load the system is supposedly in a safe position, according to the classical theory of elastic stability. However this is not completely true. The system may buckle at load levels much lower than the critical value due to the simultaneous effects of imperfections and dynamic disturbances. For systems liable to unstable post-buckling behavior, the safe pre-buckling well is delimited by the saddles associated with the unstable post-buckling path. The heteroclinic or homoclinic orbits emerging from these saddles define the safe region. The geometry and size of the safe region is here analyzed using the mathematical methods of classical mechanics, in particular Lagrangian or Hamiltonian mechanics. This is a first step in the evaluation of the integrity of the dynamical system.
Laís Corrêa, Giseli Aparecida Braz Lima, Valdemir Garcia Ferreira, Universidade de São Paulo, Brazil.
Abstract. The purpose of this work is to present a new polynomial convection scheme for solving complex fluid dynamics problems. The scheme is evaluated in linear and nonlinear hyperbolic conservation laws and then is applied for simulating axisymmetric flow with moving free surfaces. From the results, the scheme shows to be a good tool for CFD.
Miguel Candezano, Universidade de São Paulo, Brazil, Patrícia Sartori, Instituto de Matemática e de Computação-USP, Brazil, Valdemir Garcia Ferreira, Universidade de São Paulo, Brazil.
Abstract. In the field of CFD exists an important problem relationed in modelating convective terms of different equations which describe fluid flows phenomena. A classical numerical implementation as FOU,CD,QUICK,HLPA,VONOS for this kind of terms contains some imperfections as: diffusion, spurious oscillations, capturing the correct peak, etc. This work provides a computational assessment of three very popular high-resolution ``upwind'''' schemes, namely WACEB, CUBISTA and ADBQUICKEST, for solving nonlinear conservation laws and related fluid dynamics problems. These schemes are analyzed and implemented in the context of the normalized variables NV of Leonard, CBC criterium of Gaskell and Lau, and TVD constraints of Harten. Using these approaches it is possible to obtain solutions well resolved, oscillation free and convergent. These schemes introduce some procedure in which the discretisation practice for the convection term is adjusted locally, based on the currently available solution, however none of them have shown to be quite robust. To evaluate and compare the proposed schemes we introduce some numerical test as follow: advection of scalar, Riemman problems for Burgers, shallow water and Euler equations. The numerical experiments show that the ADBQUICKEST scheme provides a best or equal perfomance that the another schemes proposed in this work to solve a variety of linear and nonlinear problems.
Giseli Lima, Laís Corrêa, Valdemir Garcia Ferreira, Universidade de São Paulo, Brazil.
Abstract. In this work, we present a new high resolution polynomial upwind scheme, namely FDPUS-C1. Numerical results are presented for 1D/2D hyperbolic conservation laws. Then, as an application, the FDPUS-C1 scheme is used for solving of 2D incompressible fluid that involves moving free surfaces. The numerical results show that the new convective upwind scheme behaves well under several CFL.
Silvio de Souza, Unversidade Federal de São João del-Rei, Brazil, Iberê Luis Caldas, USP Instituto de Física, Brazil, José Balthazar, UNESP, Brazil, Reyolando Brasil, University of São Paulo, Brazil.
Abstract. The dynamics of the systems with non-ideal energy source, represented by a limited power supply, are investigated. As examples of non-ideal problems, we analyze chaotic dynamics of an impact oscillator and a Duffing oscillator. We characterize these systems in two-dimensional parameter space by using the largest Lyapunov exponents identifying self-similar periodic sets, such as Arnold tongues and shrimp-like structures. In addition, we observe multistabilities associated with fractal basin boundaries.
Haroldo Campos Velho, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. Data assimilation is an essential step for operational forecasting systems by means of a weighted combination between observational data and data from a mathematical model. Several schemes have been proposed to address this relevant issue. In this talk, it will be described and recent techniques for data assimilation: Kalman filter, variational method, particle filter, and artificial neural network. The performance of different schemes are evaluated by Lorenz system under chaotic regime.
Active Aeroelastic Control for Helicopter Rotor Vibration Reduction in the Offshore Environment, Rodrigo Almeida, Roberto Luiz da Cunha Barroso Ramos, UFABC, Universidade Federal do ABC, Brazil.
Abstract. This paper presents an analytical control design methodology for helicopter blade-sailing reduction through individual blade root control (IBRC), actuating on the blade pitch. The research is based on helicopter operations at adverse wind conditions in the offshore environment. The IBRC actuates only during rotor engagement and disengagement, which are the critical operations, when blade-sailing may be so strong that the blade can hit the helicopter fuselage. The control design is based on a linear aeroservoelastic flapping oscillator model with constant coefficients, including vertical wind gust effects. The results show that for blade root actuator limits of ±4.8º, the proposed controller can prevent blade strikes from occurring.
Magno Enrique Meza, Universidade Federal do ABC, Brazil.
Abstract. Control theory is much used in engineering to stabilize a given dynamical system at a desired equilibrium point or to confine its trajectories to a region. Extinction of species is one of the most serious problems facing fishery and, to avoid it, different policies are applied. The threshold policy (TP) is a harvesting strategy commonly used in fisheries all over the world, and also is a special and simple case of the variable structure control (VSC). In this paper, the concept of virtual equilibrium point is used to design the TP, the TP with delay (TPD), and the TP with hysteresis and delay (TPHD). It is shown that the TPD and TPHD proposed in this paper avoid the extinction of species. We use example that Loehle (2006), but with two discretization types, the first discretization is the standard scheme (forward Euler), in which numerical instabilities exist in the numerical solutions, and the second discretization is the nonstandard scheme, in which numerical instabilities do not occur. Three different logistic discrete time models subject to the TPD and TPHD are studied. We consider uncertainties in the intrinsic growth rate, in the carrying capacity, in the population density, and in the effort policy as well as an overexploitation situation. In addition, an eight-time step lag in the control policies is also introduced. The TPD and TPHD stabilize the population density at positive values, with a suitable choice of the threshold level, thus avoiding the risk of extinction. The important novel characteristic of the TPD and TPHD is that both ensure that, even though the system is subjected to uncertainties and a period of overexploitation, the system eventually stabilizes in bounded oscillations in a desired safe region of the state space.
Ananth Komanduri, Gilberto Arantes Jr, University of Bremen, Germany, Luiz Martins-Filho, Universidade Federal do ABC, Brazil.
Abstract. This paper attempts to describe an experimental satellite dynamic simulator, and to study and to propose control functions for the vehicle position and attitude. The device under consideration is the second generation of Lu- Vex project, designed and constructed at Center for Applied Space Technology and Microgravity (ZARM), University of Bremen, Germany. This satellite dynamic simulator allows us to investigate some aspects of the dynamic behaviour of a real satellite simplifying the problem by reducing the degrees of freedom to 3 instead of 6. The proposed strategies for the control function design are based on Sliding Mode Control (SMC) and Linear Quadratic Regulator (LQR) approaches. The considered actuators are jet thrusters modulated using a Pulse-Width Pulse-Frequency (PWPF) modulator. The proposed control laws are tested using numerical simulations of the LuVex virtual model. The results show some features, adequacy and problems of the two tested approaches for the LuVex position and attitude control.
Adrielle Santana, Luiz Martins-Filho, Universidade Federal do ABC, Brazil, Gilberto Arantes Jr, University of Bremen, Germany, Ricardo Duarte, Universidade Federal de Minas Gerais, Brazil.
Abstract. This work deals with the implementation of a digital control approach for artificial satellites attitude, using a Digital Signal Processor (DSP). In a first step, the controller design considers a continuous time system, aiming the adequacy of Linear Quadratic Regulator (LQR) and Linear Quadratic Gaussian Regulator (LQG) approaches to the kinematic and dynamic models of the satellite attitude, using simulation tests in MATLAB/SIMULINK environment. The following step consists of the design of a digital version of the controller running in the DSP, while the satellite model simulation stays being done in MATLAB/SIMULINK. The satellite model adopted in this works is based on the main characteristics of the Multi Mission Platform satellite (PMM), developed by the Brazilian Institute for Space Research (INPE). The presented results concern the initial tests of DSP input/output data synchronization, of communication between DSP and MATLAB/SIMULINK, and the analysis of software/hardware delays, using a test program, and also tests of the digital control performance in satellite attitude stabilization.
Antonio de Brum, Universidade Federal do ABC - UFABC, Brazil.
Abstract. This paper discusses an attitude determination method that can be used by imaging spacecrafts, such as remote sensing satellites. In a previous work, BRUM (1999) demonstrated the viability of using on-board acquired and processed remote sensing images to determine the attitude of the imaging satellite. In that work, SPOT panchromatic images of the Earth (10meter/pixel resolution) were used to determine the satellite attitude angles up to the accuracy of 0.03° - roll; and 0.02° - pitch. In this work we review this concept and discuss its applicability to the navigation of other space vehicles with imaging capability, for instance those orbiting other bodies in the solar system. The whole process involves the establishment of vector relations between imaged points and the satellite mass centre. The points of interest in the image represent visible landmarks which were previously named, well identified (in terms of their geographic coordinates: latitude, longitude and altitude), catalogued and stored for further use by the image processing software. In this proposal, the imaging procedure accomplished on board, with use of real time image acquisition and processing, includes an image search for catalogued points and, as a consequence of the identification in the acquired image of some known points (with use of pattern recognition software), the vehicle attitude can be determined. This method is particularly appropriate in the autonomous attitude determination of vehicles over a specific terrain where no other sources of navigational information is available except that obtained from the imaging procedure. This sort of solution to the navigation problem is often called image navigation. It is proposed for the navigation of missions over Earth surface or over the surface of other bodies in the solar system, where imaging in a proper resolution can be accomplished. An advantage of the proposed method is that it can be implemented without inclusion of any extra piece of hardware, but exclusively via software. Thus, a new level of redundancy (and safety) in the spacecraft attitude determination system can be achieved.
Cayo Francisco, Universidade Federal do ABC, Brazil.
Abstract. The main purpose of this work is to present the problem of the interaction between an isotropic turbulent flow and a shock wave. We present the state of art in the problem, discuss some of its aspects and derive a model to describe the predicted amplification of vorticity through the interaction.
Elzbieta Jarzebowska, Warsaw University of Technology, Poland.
Abstract. The paper revises constraints put upon mechanical systems and ways they are approached in control design. We demonstrate, based on examples, that a typical classification of constraints, modeling methods of analytical mechanics, which follow this classification and constraints handling in control design, underexploit the role of effective constraints modeling in overall control design.
Alexei A. Mailybaev, Moscow State Lomonosov University, Russia.
Abstract. A general linear vibrational system with multiple degrees of freedom subjected to parametric excitation is considered. It is assumed that the system is statically unstable but close to a critical point, the excitation amplitude and damping are small, and the excitation frequency is arbitrary. A new stabilization condition is derived in terms of integrals depending on eigenfrequencies and modes of the undisturbed conservative system and the symmetric excitation matrix. As a special case, an approximation for high frequency excitation is deduced from this condition. Influence of damping on stabilization region is shown to be very small. Two examples for systems with one and two degrees of freedom are presented. It is shown that stabilization of statically unstable systems is possible for low, medium and high excitation frequencies. The obtained results are extended to the case of infinite degrees-of-freedom systems. The classical Chelomei''s problem of stabilization of a statically unstable elastic column by axial harmonic vibration is reconsidered. The excitation frequency is assumed to be arbitrary. Two types of boundary conditions of the column - simply supported and hinged-clamped ends are considered. Both cases are studied analytically with the check by the numerical analysis. For undamped columns with the axial force close to the critical stability value, finite number of triangular stabilization zones appear. This implies that high-frequency stabilization is not possible. The influence of the external damping on stabilization regions is shown to be small. With addition of the internal damping, a continuous stabilization region appears for small excitation amplitudes, which starts at medium frequencies and extends to high-frequency range.
José Rodrigues, Universidade Estadual Paulista/Faculdade de Engenharia de Bauru, Brazil.
Abstract. Systems based on artificial neural networks have high computational rates due to the use of a number of simple processing elements and the high degree of connectivity between these elements. In this paper, a neural approach is developed to aid in designs of electric grounding. More specifically, artificial neural networks are used for mapping of the ground in horizontal layers. Simulation results are presented to demonstrate the validity of the proposed approach.
Luciano Barbanti, Berenice Damasceno, José Balthazar, UNESP, Brazil.
Abstract. Abstract: Time scale calculus is a unification of the theory of difference equations and of the differential equations one. Taking in account this theory it was defined in the last decade the Riemann delta and nabla-integral, alfa-integral, the Lebesgue and nabla-integrals, and the Henstock-Perron- Kurzweil ones, applied to dynamical systems. Along with these definitions, the notion of the Riemann-Stieltjes □ - integral was done in 2009, opening in this way the possibility in to apply the time scale calculus on the field of the integral equations too. But, when considering discontinuous functions the Riemann-Stieltjes □-integral it presents important well known gaps inherent to the classical Riemann-Stieltjes integral. In this work we give the definition of a new kind of integral, the odd-meshed filter integral, that generalizes in a proper sense the Riemann- Stieltjes □-integrals, and avoids some of such gaps.
Airam Sausen, Northwest Regional University of the Rio Grande do Sul State, Brazil.
Abstract. The main purpose of this paper is to present sensitivity analysis of a dynamic model for a pipeline-separator system under slug flow with 5 (five) coupled nonlinear ordinary differential equations and 6 (six) tuning parameters. Sensitivity analysis is an important tool in the process of model building, because it shows how the system reacts to a change in their tuning parameters, which increases the uncertainty of the model. It also gives an opportunity to better understand the dynamic behavior of the system.
Lorena Cardoso, UNICENTRO/USP, Brazil.
Abstract. In this work, we will take the idea of generalization of the concept of differentiability in Banach spaces, proposed in Article "A generalization of the concept of differentiability", writen by MIRANDA and FICHMANN, to create the concept of limits in sections. More general concepts of limits permit a broader concept of continuity, as well as differentiability. The fact that the concept is entirely new and original opens many possibilities for applications in several areas of mathematics. Keywords: Sections in Banach spaces, Differentiability in Banach Spaces, Nemytskii operator.
Caroline Martins, UNESP, Brazil.
Abstract. We present a nonlinear symplectic map that describes alterations of the magnetic field lines inside the tokamak plasma due to the presence of a robust torus (RT) at the plasma edge. This RT prevents the magnetic field lines to reach the tokamak wall and reduces, in its vicinity, the islands and invariant curves destruction due to resonant perturbations. The map describes the equilibrium magnetic field lines perturbed by resonances created by ergodic magnetic limiters (EML). We present results obtained for twist and non-twist mappings derived for monotonic and non-monotonic plasma current density radial profiles, respectively. Our results indicate that the RT implementation would decrease the field line transport at the tokamak plasma edge.
Cristiano Strieder, INPE - Instituto Nacional de Pesquisas Espaciais, Brazil - Reinaldo Rosa, National Institute for Space Research - INPE, Brazil.
Abstract. In this paper we introduce a new C++ numerical code for the so-called Gradient Pattern Analysis, which is able to characterize different morphological shapes by means of calculating the object''s gradient asymmetry. The application was developed under Linux to run as a command line tool.
Renner Martins, ITA, Brazil.
Abstract. The objective of this paper is to propose a process for treatment of Dead Codes in software used on aircraft systems, attending the requirements of the aeronautical standard RTCA/DO-178B.
Ligia Rodrigues Prete, Ailton Shinoda, Universidade Estadual Paulista - UNESP, Brazil.
Abstract. Este trabalho aborda o estudo de um cenário proposto para análise do comportamento de redes mistas, fazendo uso de métodos computacionais inseridos em um simulador de eventos discreto (Network Simulator). As métricas de modelagem consideradas no trabalho foram à movimentação de um nó sem fio e à estatística média de vazão quando ocorre o aumento de nós móveis na rede.
Alice Kozakevicius, Universidade Federal de Santa Maria, Brazil.
Abstract. In the present work we give a functional analytic framework for Galerkin projection for delay-differential equations. Numerical examples are presented as well as the corresponding computed errors in order to illustrate the dependence of the formulation with respect to the chosen basis and its number of elements.
Marco Pinheiro, Universidade Federal de Santa Maria, Brazil.
Abstract. Sinais no tempo de comportamento aleatório são comuns na natureza, como por exemplo, ação de vento, a qual pode apresentar correlações diferentes ao longo de uma estrutura. Neste artigo é mostrada uma maneira simplificada de se obter diferentes sinais no tempo a partir do espectro em freqüência de vento atuante.
Rodrigo Moruzzi, Samuel Oliveira, UNESP, Brazil.
Abstract. Nesse artigo foi analisado o processo de floculação aplicada à separação de partículas sólidas em meio aquoso. Para tal foram empregados modelos em reatores estáticos e contínuos. Os resultados ajudaram a compreender o fenômeno no que tange aos seus parâmetros operacionais e de projeto.
Luiz Carlos Sanches, Unesp Ilha Solteira, Brazil.
Abstract. A aplicação da transformada de Fourier como técnica alternativa ao Método dos Elementos de Contorno (MEC) tradicional é objeto principal do presente trabalho. O chamado Fourier-MEC generaliza a metodologia padrão e pode ser aplicado em todos os casos onde os coeficientes do operador diferencial parcial de um determinado problema são constantes. A idéia principal consiste em evitar a transformada inversa de Fourier de uma solução fundamental desconhecida, trabalhando diretamente com a transformada de Fourier desta solução. O esquema em questão é baseado no teorema de convolução e de Parseval. Com estes dois teoremas e mais algumas considerações sobre o conceito de distribuições podem ser determinadas Equações Integrais de Contorno (EIC) equivalentes para o domínio transformado de Fourier. Este novo procedimento leva equações matriciais semelhantes às aquelas obtidas via MEC padrão, ou seja, todas as variáveis, vetores e matrizes do Fourier-MEC apresentam a mesma configuração se comparados com a metodologia tradicional.
Marcio Bazani, UNESP, Brazil.
Abstract. This study is the numerical and experimental flow-dimensional, viscous, incompressible, with constant heat transfer through a narrow channel containing a rectangular array of obstacles. The experimental approach involves determining the coefficient of heat transfer and temperature measurements in wake thermal for comparison with the numerically simulated results and data from literature. It was used a commercial tool for computational fluid mechanics.
Renato Crivellari Creppe, UNESP - FEB, Brazil - Edison Aparecido Goes, UNESP, Brazil - José Rodrigues, Universidade Estadual Paulista/Faculdade de Engenharia de Bauru, Brazil - Jose Alfredo Covolan Ulson, Luiz Porto, UNESP, Brazil.
Abstract. The main purpose in this paper is to describe a methodology for the identification of the site of a short circuit in an electric distribution line. This calculation is crucial for the rapid reestablishment of the electric power supply. This paper reports on the application of a multilayer perceptron-type Artificial Neural Network (ANN) operating as a pattern classifier to identify a section of a class 15 kV distribution line subjected to a ground phase short circuit. The configuration employed, figure 5, contains three sections of different lengths and the failures (short circuits) were simulated using the Alternative Transient Program (ATP) software.
Pedro da Costa Jr., FEB, UNESP - Univ Estadual Paulista, Brazil - Luiz Gonçalves Jr., Univ Estadual Paulista - UNESP, Brazil - Claudio de Aquino, Faculdade de Engenharia de Bauru, UNESP - Univ Estadual Paulista, Brazil - André Nunes de Souza, José Eduardo Castanho, UNESP, Brazil - Maria G. Zago, Universidade Estadual Paulista, Brazil.
Abstract. Este artigo apresenta uma investigação das características de geradores síncronos para os possíveis modos de operação. Trata-se do desenvolvimento de uma nova ferramenta computacional que proporciona ao usuário uma avaliação direta do comportamento de geradores síncronos. Exemplos ilustram o uso do aplicativo para avaliar o comportamento dinâmico de geradores síncronos.
André Nunes de Souza, UNESP, Brazil - Pedro da Costa Jr., FEB, UNESP - Univ Estadual Paulista, Brazil - Renato de Oliveira, Maria G. Zago, João Paulo Papa, Danilo Sinkiti Gastaldello, Universidade Estadual Paulista, Brazil.
Abstract. O artigo propõe uma técnica para ser utilizada no planejamento de sistemas de energia elétrica, promovendo a identificação de fraudes em instalações residenciais, considerando padrões estatísticos e a natureza aleatória das cargas. A metodologia consiste na utilização das características de unidades consumidoras e de seus padrões de hábito de consumo.
Anna Warminska, Stefan Fijalkowski, Lublin University of Technology, Poland.
Abstract. Results of theoretical and experimental investigations of loss of energy which arise in the small refrigerating compressors used in agriculture and food industry have been presented in the paper. Operation of the refrigerating compressor has been treated as a system, composed of subsystems which represent the main parts of the set. In each subsystem all internal processes have been defined and then relationships between subsystems and the external environment have been found. On the basis of the proposed model, the main factors and sources of the internal and external losses and their localization have been distinguished. The analysis has shown that the most essential energy losses have occurred during starting period of the refrigerating compressor work. The relationship between an amount of refrigerated liquid and energy used in cooling process has been determined.
Rodnei Passolongo, UNESP - Ilha Solteira, Brazil.
Abstract. Este trabalho apresenta uma análise da gaseificação da palha da cana em uma usina de açúcar e álcool, sob o ponto de vista termodinâmico, termoeconômico e econômico. São estudadas duas configurações de planta, sendo uma a planta de vapor convencional de uma usina, e outra uma planta para gaseificação da palha em ciclo combinado. Os resultados mostram que através da gaseificação é possível duplicar a quantidade de eletricidade gerada pela usina. Entretanto, a tecnologia da gaseificação exige um maior valor de venda da eletricidade para apresentar viabilidade financeira.
Ricardo Alan Ramos, UNESP - Ilha Solteira, Brazil.
Abstract. Neste trabalho é analisado sob o ponto de vista termodinâmico e termoeconômico o aproveitamento da vinhaça num sistema de cogeração de energia de uma usina sucroalcooleira, tendo sido constatado um aumento significativo na geração de energia elétrica.
Regis Schuch, Sérgio Dill, Paulo Sausen, Edson Padoin, Universidade Regional do Noroeste do Estado do RGS (UNIJUI)
Nabil Aouf, Cranfield University, Great Britain.
Abstract. Control Systems and Navigation, Signal Processing and Information Fusion, Autonomy of Systems and Decision making, Real time Systems and Embedded systems, Vision based Guidance and Tracking Defence, Security and Surveillance systems
João Fernandes, Universidade Estadual Paulista, Brazil.
Abstract. O objetivo do curso é apresentar o projeto acústico de um ambiente (auditórios, igrejas, teatros, anfiteatros, estúdios, residências, salas de aula, ginásios, boates, etc.). O curso compreende o estudo de isolamento e tratamento acústico de ambientes bem como a indicação dos equipamentos eletroacústicos para sonorização de ambientes. O curso oferecerá aos participantes as técnicas para reduzir o risco de perda auditiva dos empregados de uma empresa. Serão estudados métodos de atenuação do ruído, técnicas de dificultar a propagação do som e a correta utilização de Equipamentos de Proteção Individual (EPI). O curso será voltado a profissionais das áreas Civil, Elétrica, Mecânica e Agronômica. Palavras-chave: Acústica, projeto, ruído, conforto, perda auditiva.
Wellington Firmino da Silva, UNICAMP, Brazil.
Abstract. The present paper consists in presenting some contributions in medical imaging to improve images acquired by means of X-Ray that bear noises. Some techniques using the MatLab tool have been applied. The major problem facing that aspect is the saturation level. When the medical imaging has a very high saturation level, it is not possible to recover the image, but when one can directly work with the image pixels, it is possible to process the image so that the noise can be removed or minimized.
Pedro Luiz Paula Filho, UNC, Brazil - Cleverson Junior Soares, Universidade do Contestado, Brazil - Angelo Tusset, UTFPR, Brazil.
Abstract. Mesmo com o avanço nas áreas de automação e programação, fazer com que os robôs autônomos executem uma ou mais tarefas de maneira conjunta é ainda um dos grandes desafios da robótica. Neste trabalho é abordada a interação com um robô autônomo, envolvendo Processamento de Imagens, Linguagens de Programação, Projeto Assistido por Computador, Otimização, eletrônica, etc. Os resultados demonstram com utilização da visão computacional no controle de um robô móvel, sendo as imagens capturadas de uma câmera e processadas, possibilitando a identificação de obstáculos e o ponto a ser alcançado utilizando a comunicação através de rádio freqüência.
Alexandre de Siqueira, Universidade do Oeste Paulista, Brazil - Messias Menegueti Junior, UNESP, Brazil - Aldo Job, Universidade do Oeste Paulista, Brazil.
Abstract. This work is about a study on image processing of natural rubber membranes. A software is being created to use wavelet and Fourier transforms in digital images of natural rubber; with these results, is expected the use of pattern recognition to those images.
Leide Caires, Universidade Estadual Paulista, Brazil.
Abstract. Na criação do modelo geométrico para análise por elementos finitos, a grande dificuldade é definir a forma geométrica, devido à complexidade da geometria. O processo de criação do modelo geométrico, inicia-se após a captura da imagem, seguido da geração de uma malha que resulte o mais próximo possível da geometria da estrutura real, pois quanto mais próximo o modelo se aproximar da estrutura real, melhor será a precisão da análise. Disposto a atender os pré-requisitos das etapas de criação do modelo geométrico e pré-processamento em análise por elementos finitos em estruturas biomecânicas envolvendo regiões ósseas, foi a ênfase deste trabalho. Foi então desenvolvido um sistema computacional, para obter modelos geométricos, através do processamento de imagens bidimensionais, imagens médicas digitais em formato DICOM, mas que também trabalha com outros formatos como BMP ou JPEG. O programa desenvolvido utiliza a Triangulação de Delaunay com restrição ou Constrained Delaunay Triangulation (CDT), para reconstrução da malha de superficie a partir do contorno das imagens utilizadas. O programa também se integra com softwares de análise por elementos finitos, a fim de completar a análise sobre a estrutura obtida.
Virginia Klausner, Instituto Nacional de Pesquisas Espaciais, Brazil - Margarete Domingues, Instituto Nacional de Pesquisas Espaciais, Brazil - Andres Papa, Instituto Nacional de Pesquisas Espaciais, Brazil - Odim Mendes Jr., Instituto Nacional de Pesquisas Espaciais, Brazil
Abstract. Using the hour data of the H component, we explored the solar quiet variations via a time-frequency gapped wavelet algorithm. Standard wavelet methods require times series to be regularly distributed in time. So, the gapped wavelet technique is suitable for analysis of data with gaps, especially in our case, using data from various magnetic stations that present gaps in the records in different periods of time. This work aims mainly to highlight and interpret the quiet daily variations over the Brazilian sector compared to the features from other twelve magnetic stations reasonably distributed over the whole Earths surface. By applying wavelet transforms to these signals, we are able to analyze both the frequency content of each signal and the time dependence of that content. After computing wavelet transforms of the data, we perform wavelet cross-correlation analysis. The wavelet cross-correlation technique is useful to isolate the period of the spectral components of geomagnetic field in each station and to correlate them as function of scale (period) between VSS and the other stations. In particular we focused our attention on Vassouras Observatory (VSS), Rio de Janeiro, Brazil, which has been active since 1915. In the next years, a brazilian network of magnetometers will be implemented and VSS can be used as reference.
Margarete Domingues, Chou Chan, Instituto Nacional de Pesquisas Espaciais, Brazil - Odim Mendes Jr., Instituto Nacional de Pesquisas Espaciais, Brazil - Marize Simoes, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. In this work a case study of a multi-scale analysis of the short and long range Eta model runs is presented. Here we compare the output of this numerical weather model to a representative local station dataset during part of a summer season. In this context, we use the variance wavelet analysis, using the continuous wavelet transform to compute the wavelet spectrum or scalogram. The Eta Model used here is a grid point weather forecast model configured with 40 km resolution. One of the characteristics of the model is the eta vertical coordinate which reduces the pressure gradient force errors near mountain regions. The time scheme applied is the forward-backward scheme for the adjustment terms and first-forward-then-uncentered scheme for the horizontal advection. Lateral boundary conditions are prescribed along a single outer line without need for boundary relaxation. The prognostic variables are temperature, specific humidity, horizontal wind, surface pressure, the turbulent kinetic energy and cloud liquid water/ice. The model has complete physics package and the cumulus convection is parameterized by the Betts-Miller scheme. The objective of this analysis is to identify the differences between the atmospheric scales present in the short-range and long-range model runs. Here we found the identification of the timescales in which long-range integration scale exhibits larger difference from the short-range integrations. This can help to indicate the weather systems of low predictability in the model. Moreover, the analysis helps to identify the weather systems that are not represented by the model in the seasonal climate integrations.
Odim Mendes Jr., INPE, Brazil - Margarete Domingues, Nalin Trivedi, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. As a kind of ground end manifestation of space weather on the the Earth, geomagnetically induced currents (GICs) can be established on the Earth's surface. At different latitudes and regions GIC-events present different features, which require much more work for an adequated understanding on the phenomena. So using ground data collected in a brazilian region this work deals with the relationship between the interplanetary observations from satellite ACE and the measurements at the ground during the GIC occurrence. In a preliminary way, the result of this study points to a promising tool to the analysis of the GIC/geomagnetic storm relationship.
Piermarco Cannarsa, University of Rome "Tor Vergata", Italy.
Abstract. Semiconcave functions are a class of nonsmooth functions that, without being subject the rigid structure of concave functions, retain most of the regularity properties coming from concavity and have important applications to optimization theory. This talk, in which I will discuss recent results obtained in collaboration with P. Wolenski, is devoted to the study of the semiconcavity of the value function of an optimal control problem of Mayer type, where the state equation is modeled by a differential inclusion. In this case, the known techniques to prove semiconcavity for parametrized control systems have to be completely revised. A new approach, in which the maximum principle in Hamiltonian form plays a major role, will be developed, and possible future directions of research will be outlined.
Peter Wolenski, Louisiana State University, USA.
Abstract. We will present a formula and sketch the proof of a formula for the subgradient of a value function in a Mayer problem. The formula involves the normal cone to the sublevel set (as is to be expected) and a normalization procedure involving the Hamilton-Jacobi equation.
Rodolfo Ranck Junior, INPE, Brazil - Leonardo Santos, INPE - Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. Este artigo apresenta um meio de suporte à decisão para, dada uma tolerância de distância total e/ou máxima entre focos da doença e facilidades, determinar o número mínimo de facilidades a serem instaladas, o que representa um melhor uso da verba pública com um melhor atendimento à população.
César Berci, UNICAMP - Universidade Estadual de Campinas, Brazil - Celso Bottura, Universidade Estadual de Campinas, Brazil.
Abstract. O controle de sistemas não lineares pode se tornar uma tarefa praticamente intratável, a depender da complexidade do sistema a ser controlado. O modelo não linear do pendulo invertido é um exemplo de sistema não linear relativamente complexo, e a implementação de um controlador para este sistema requer uma série de considerações e simplificações. O presente trabalho visa implementar um controlador genético para controlar esse sistema utilizando computação massiva para encontrar o valor da entrada que leva a saída do sistema para o valor de referência, utilizando o modelo não linear do pendulo invertido sem qualquer simplificação.
João Fernandes, Universidade Federal Fluminense, Brazil.
Abstract. The Estereoscopy is a process in Computer Vision 3-D that enables the recover of three-dimensional information from bi-dimensional images. The central problem of Estereoscopy is to match the two input images to obtain the disparities associated with points in the scene. In this paper, we study a stochastic approach to the process of matching images, detailing three optimization algorithms applied to stereo correspondence. We made also experiments with these algorithms, aiming to compare their performance when applied to the problem.
Fabio Luis Marques dos Santos, Luiz Carlos Sandoval Goes, Instituto Tecnologico de Aeronautica, Brazil - Alberto Luiz Serpa, UNICAMP, Brazil.
Abstract. In this paper the H-infinity control strategy is addressed. This control technique was tested in a system where saturation is present, the semi-active suspension problem and was evaluated using performance indexes regarding comfort and road handling, and solved by the use of some specific tools of the MATLAB software. The main goal is to obtain optimal performance, in order to minimize the sprung mass (chassis) acceleration and to ensure road-holding characteristics. A comparison is then made with a passive system, by means of numerical simulation, using a quarter-car model, real road profiles, by means of the performance indexes and frequency response comparisons. A single-sensor approach is also suggested, to reduce the number of sensors used per quarter-car model.
Thiago Homem, Universidade Estadual Paulista - UNESP, Brazil - Antonio Balbo, UNESP de Bauru, Brazil - Helenice Florentino, IB - UNESP, Brazil.
Abstract. O objetivo deste trabalho é a aplicação do método de Pontos Interiores e o método Branch and Bound em dois modelos de otimização que auxiliem na escolha da plantação de variedades de cana-de-açúcar. Os resultados obtidos mostram que o uso deste procedimento híbrido promove uma boa performance computacional e apresenta soluções confiáveis.
Emerson Ravazzi Pires da Silva, UNESP - Campus de Ilha Solteira (SP), Brazil - Edvaldo Assunção, UNESP - Univ Estadual Paulista - Campus de Ilha Solteira, Brazil - Marcelo Carvalho Minhoto Teixeira, Unesp - Campus de Ilha Solteira (SP), Brazil - Flávio Faria, UNESP - Universidade Estadual Paulista, Brazil - Rodrigo Cardim, UNESP - Ilha Solteira, Brazil.
Abstract. A technique of PDC fuzzy controller design for nonlinear continuous-time systems is proposed in this paper. It is supposed that the nonlinear plant is subject to structural failures, which can be considered as polytope uncertain. The nonlinear systems are represented through fuzzy models proposed by Takagi-Sugeno. The controller design is made through conditions based in Linear Matrix Inequalities (LMIs), which can be easily solved using convex programming techniques. Finally, a numerical example and its simulation illustrate the efficiency of the proposed methodology.
Valdemir Garcia Ferreira, Universidade de São Paulo, Brazil.
Abstract. No presente minicurso será apresentada uma revisão breve do estado da arte em simulação computacional de alguns problemas em dinâmica dos fluidos. A maior parte do minicurso será destinada a exemplos e ilustrações de simulações numéricas de escoamentos incompressíveis. A introdução ao tema será feita gradativamente por meio da resolução númerica de equações modelo 1D, tais como equação da condução de calor (parabólica), equação de advecção (hiperbólica) e equação de Poisson (elíptica). A proposta do minicurso é mostrar que dinâmica dos fluidos computacional é a ciência de construir soluções numéricas para equações de conservação, avançando a solução no espaço e no tempo para obter uma descrição numérica do escoamento de interesse. Os tópicos a serem abordados no minicurso são resumidos como segue: - descrever técnicas para a marcha no tempo e o método de diferenças finitas; - discretizar as equações modelo 1D; - apresentar o modelo fundamental em dinâmica dos fluidos (as equações de Navier-Stokes); - compreender o significado físico de cadas termo das equações de Navier-Stokes; - introduzir um algoritmo de cálculo para as equações de Navier-Stokes; - mostrar uma variedade de simulações de escoamentos incompressíveis; - discutir alguns problemas práticos usando filmes ilustrativos. O presente minicurso é direcionado, principalmente, a alunos de graduação que tenham alguma familiaridade com cálculo avançado, cálculo numérico e física elementar. E o seu objetivo principal é mostrar ao aluno como resolver, no contexto de diferenças finitas, as equações de Navier-Stokes para o caso incompressível.
Hasnaa Zidani, ENSTA ParisTech, France.
Abstract. We are interested in the characterization of the value function of a state-constrained control problem lacking controllability assumptions. In the unconstrained case, it is possible to derive the characterization of the value function by means of a Hamilton-Jacobi-Bellman (HJB) equation. This equation expresses the behavior of the value function along the trajectories arriving or starting from any position x. In the constrained case, when no controllability assumption is made, the HJB equation may have several solutions. Our first result aims to give the precise information that should be added to the HJB equation in order to obtain a characterization of the value function. This result is very general and holds even when the dynamics is not continuous and the state constraints set is not smooth. We shall also discuss some stability results for penalized control problems.
João Fernandes, Universidade Estadual Paulista, Brazil.
Abstract. Muitos pesquisadores enfrentam algumas dificuldades ao trabalharem com a escala em decibels. É muito comum encontrar-se em trabalhos científicos, operações impróprias com dB: operações aritméticas de soma ou subtração, cálculo da média aritmética e desvio padrão, obtenção de vários parâmetros estatísticos inadequados, análise de variância, e até o uso de testes estatísticos paramétricos, como teste t ou Tukey. A escala em decibels se caracteriza por ser logarítmica e ter o valor zero relativo. Assim, em termos científicos, pode-se dizer que o processo de mensuração de níveis de pressão sonora, em decibels [dB], pertence ao nível (ou classe) das escalas intervalares, que se caracteriza por ter o ponto zero e o padrão da medida arbitrários. Outros exemplos comuns dessas escalas são as escalas termométricas (lineares) de graus Celsius ou Fahrenheit. Nas escalas intervalares lineares são permitidas apenas as operações de adição e subtração; na escala em dB (logarítmica) nem estas operações são permitidas. Nunca devem ser realizadas operações de multiplicação ou divisão. Para a escala em decibels (logarítmica e com zero relativo), é possível trabalhar-se com a distribuição de freqüências e com a mediana dos valores das medições. Para os testes de significância entre grupos deve-se usar os testes não paramétricos (prova de Kolmogorov-Smirnov, prova de Wilcoxon, prova dos sinais, prova da mediana, prova de Friedman, Coeficiente de correlação de Spearman e de Kendall, etc.).
Santos Miranda, UFERSA, Brazil - Claudio Garcia, USP, Brazil.
Abstract. Subspace identification has been a topic of research along the last years. Methods as MOESP and N4SID are well known and they use the LQ decomposition of certain matrices of input and output data. Based on these methods, it is introduced the MON4SID method, which uses the techniques MOESP and N4SID.
Ailton Shinoda, Universidade Estadual Paulista - UNESP, Brazil.
Abstract. Este artigo descreve a implementação otimizada do código convolucional turbo, em ponto fixo, de um sistema OFDM baseado no controle adaptativo da taxa de dados da camada física do WiMAX de acordo com o padrão IEEE 802.16
Fernando Barros Rodrigues, Universidade Estadual Paulista UNESP, Brazil - José Garcia, Universidade Estadual Paulista - UNESP, Brazil - Lizete Fernandes Garcia, UNESP, Brazil - Gisele de Carvalho Apolinário, Universidade Estadual Paulista - UNESP, Brazil.
Abstract. In this paper is proposed a strategy of control designed to improve the robustness and the stability of system with parametric variation and sensor fault. A Variable Structure Controller with Sliding Mode was designed to improve the robustness of the system. Only the plant output is available and so the use of the observer is required. A scheme for sensor fault detection and accommodation is presented so that when the fault is present, the controller is automatically adapted for the fault of the sensor.
Fran Lobato, Valder Steffen Jr, Federal University of Uberlândia, Brazil.
Abstract. The aim of this work is to define a systematic methodology to solve Optimal Control Problems (OCP) by using the Multi-Particle Collision Algorithm. The methodology proposed is applied to benchmark problems. The results obtained are considered satisfactory as compared with other strategies.
Emanuel Lima, Universidade de Sao Paulo Instituto de Física de São Carlos, Brazil.
Abstract. The dynamics of photoassociation and subsequent vibrational stabilization driven by laser pulses is investigated. Optimal controls of the processes are seeking by employing an accelerated monotonic scheme derived from a Two-point Boundary-value Quantum Control Paradigm. Calculations within a model system for the electronic ground-state s-wave collision of O+H are presented. The optimized fields and corresponding population dynamics are analyzed. It is shown that it is possible to achieve very high yields in the molecular vibrational ground-state.
Elmer Villarreal, UFERSA, Brazil.
Abstract. The principal aim of this paper is to study the problem of stabilization by static output feedback for linear descriptor system. Presented sufficient conditions for existence of a S-stabilizing output feedback control in terms of two coupled matrix, where the solutions to these equations can be obtained, for the systems to verify the condition (m+p>q).
Alípio Barbosa, Universidade Federal de Minas Gerais, Brazil - Lucas Ribeiro, João Matheus Arantes, Instituto Tecnológico de Aeronáutica, Brazil.
Abstract. Métodos de otimização multiobjetivo têm como principais finalidades minimizar a distância entre a frente não dominada e a frente pareto ótimo e encontrar um conjunto de soluções que sejam as mais diversas possíveis. Na expectativa de trilhar caminhos para alcançar esses objetivos, foi desenvolvido um algoritmo genético adaptativo com elitismo (ANSGA). O conceito de população externa e operadores adaptativos foi adotado. Três problemas teste foram avaliados como um indicativo do desempenho do algoritmo adaptativo.
Flávio de Melo, Instituto Tecnológico de Aeronáutica, Brazil - Karl H. Kienitz, ITA, Brazil - José Fernando Brancalion, EMBRAER, Brazil.
Abstract. Abstract Tracking agile aircraft under high accelerations generally demands sophisticated models for determining trajectories with desirable accuracy. Often this raises complexity of the estimation algorithm as it gives rise to more elaborated methods for both taking model nonlinearities into account and handling a greater number of state variables that describe the model. The approach of this work recalls a 3D model based on flight dynamics of a point of mass for which augmentation to the Extended Kalman-Bucy filter (EKBF) is proposed. Two methods of augmentation to the EKBF filter are studied: (i) use of second-order terms to approximate the model according to the Daum''s theory; (ii) deployment of a neural network coupled to the filter for compensation of modeling and calculation errors. The evaluation of the filters performance is accomplished by measuring nonlinearities, biasness, accuracy and robustness. The designed filters are suitably accurate and robust for tracking targets in air combat scenario.
Sandro da Silva Fernandes, ITA, Brazil.
Abstract. In this paper, a systematic study of optimal trajectories for Earth-Moon flight of a space vehicle is presented. The optimization criterion is the total characteristic velocity and two dynamical models are used. The optimization problem has been formulated using the patched-conic approximation or a simplified version of the planar circular restricted three-body problem (PCR3BP). In both cases, the problem has been solved using a gradient algorithm in conjunction with Newton-Raphson method.
Othon Winter, UNESP, Brazil.
Abstract. The asteroid 2001SN263 was revealed in February 2008 as the first known near-Earth triple asteroidal system (Nolan et.al, 2008). Using preliminary information about the orbit and the physical composition of such asteroid (Becker et. al, 2008), we have performed numerical integrations in order to study the orbital dynamics of the system, and the effects of the gravitational perturbations of the planets Mars, Earth and Jupiter on such system. We discuss the evolution of each body when only the three asteroids are considered (mutual perturbation), and the effects due to Jupiter and Mars, and also due close-approaches between the triple asteroid and the Earth. Then, we consider a system composed by seven bodies: Sun, triple asteroid system, Mars, Earth and Jupiter, in order to analyze the perturbation on the triple system of asteroids.
Pedro Brasil, Universidade Estadual Paulista, Brazil - Tadashi Yokoyama, Unesp, Brazil - Rogerio Deienno, Universidade Estadual Paulista, Brazil - Erica Nogueira, Observatório Nacional, Brazil.
Abstract. Neste trabalho realizamos estudos sobre a estabilidade de satélites de Júpiter utilizando cenários de migração planetária. Por outro lado, também através de abordagens semi-analíticas investigamos as possíveis ressonâncias existentes em satélites fictícios, limite de sobrevivência dos regulares (fictícios e reais) bem como a captura de planetesimais como satélites irregulares.
Rogerio Deienno, Universidade Estadual Paulista, Brazil - Tadashi Yokoyama, Unesp, Brazil - Erica Nogueira, Observatório Nacional, Brazil.
Abstract. O propósito deste trabalho é realizar uma análise exploratória dos efeitos da migração planetária como proposto no modelo de Nice sobre os satélites regulares atuais de Urano, assim como sobre outros fictícios que poderiam ter existido além da órbita de Oberon até a distância de semi-eixo crítico. Também analisaremos alguns processos de captura de satélites irregulares provenientes de encontros próximos planetesimais-satélites e planetesimais-Urano. Nosso estudo mostrará a necessidade de uma metodologia diferenciada para tal estudo, envolvendo o uso de polinômios para auxiliar na dinâmica da evolução dos planetas gigantes.
Antonio Balbo, UNESP de Bauru, Brazil.
Abstract. Este mini-curso tem por objetivo abordar princípios básicos e teóricos, em otimização linear e não-linear, métodos de penalidade clássicos e de barreira, métodos de pontos interiores inseridos na metodologia primal-dual, bem como, a aplicação destes em modelos matemáticos de Despacho e de Fluxo de Potência Ótimo (FPO), inseridos na Área de Engenharia Elétrica. Nível: É direcionado a alunos da graduação, mestrado e doutorado; Área: Ciências Exatas e Engenharias. Ementa: 1) Introdução à otimização; 2) Problemas restritos; 3) Métodos de penalidade, de Barreira e de Barreira Aumentada; 4) Métodos Primal-Dual de Pontos Interiores; 5) Aplicações em Modelos de Despacho e de FPO. Duração: 03 horas
Luiz Francisco Sanches Buzachero, UNESP - Universidade Estadual Paulista, Brazil - Edvaldo Assunção, UNESP - Univ Estadual Paulista - Campus de Ilha Solteira, Brazil - Marcelo Carvalho Minhoto Teixeira, UNESP - Campus de Ilha Solteira (SP), Brazil - Flávio Faria, UNESP - Universidade Estadual Paulista, Brazil - Emerson Ravazzi Pires da Silva, UNESP - Campus de Ilha Solteira (SP), Brazil.
Abstract. This work discusses a practical implementation of design techniques of robust controllers based on the use of LMIs for linear systems with states feedback. Also present formulations to enter restrictions of decay rate in the design of the control law of the controlled system and techniques to optimize robust controllers norm. The plant may be subject to structural failure.
Gustavo Abreu, Faculdade de Engenharia de Ilha Solteira-UNESP, Brazil - Vicente Lopes Junior, Universidade Estadual Paulista UNESP Departamento de Engenharia Mecânica, Brazil.
Abstract. This paper presents an active damping control of a smart truss structure using pair of piezoelectric stack actuators collinear with force transducers and a H2 optimal control strategy. A finite element model of the structure is constructed using the three-dimensional frame elements subjected to axial, bending and torsional loads considering electro-mechanical coupling between the host structure and piezoelectric stack actuators. In this paper, the active member placement is determined by using the fraction of modal strain energy as an optimal index. The performance objectives and the high frequency unmodeled dynamics are considered in the controller design to produce a H2 optimal controller based on force feedback. The purpose of the controller is to minimize the effect of disturbances on the entire structure. The numerical simulation results demonstrate that the active piezoelectric strut actuator and the H2 control strategy can effectively reduce truss vibration in the presence of several operating conditions.
Célia Reis, FEIS/UNESP, Brazil - Neusa Silva, UNESP, Brazil.
Abstract. Neste trabalho efetua-se uma análise dos extremos da resposta degrau de sistemas de controle lineares, com pólos e zeros reais distintos. Condições suficientes são determinadas para não ocorrência de extremos quando zeros do sistema estão entre o pólo dominante e o mais rápido. Os resultados são apresentados em termos da configuração pólo-zero da correspondente função de transferência.
Neusa Silva, UNESP, Brazil - Marcelo Carvalho Minhoto Teixeira, Unesp - Campus de Ilha Solteira (SP), Brazil - Edvaldo Assunção, UNESP - Univ Estadual Paulista - Campus de Ilha Solteira, Brazil - Erica Machado, UNESP- Universidade de São Paulo, Brazil - Célia Reis, FEIS/UNESP, Brazil.
Abstract. No projeto de reguladores quadráticos ótimos a compensação ótima das condições iniciais do controlador pode melhorar significativamente o desempenho do sistema controlado. Este artigo apresenta o método para compensação das condições iniciais no controlador, no caso considerado integral, baseado em Desigualdades Matriciais Lineares (em inglês, Linear Matrix Inequalities (LMIs)), para sistemas discretos no tempo com incertezas. A aplicação do método proposto no controle de um pêndulo invertido comprova a sua eficácia.
André de Paula, Universidade Estadual Paulista-UNESP, Brazil - Jefferson Leone Silva, José Garcia, Universidade Estadual Paulista - UNESP, Brazil - Lizete Fernandes Garcia, UNESP, Brazil - Fábio Durão, Universidade Estadual Paulista - UNESP, Brazil.
Abstract. The main objective of the project is the exploration of the control technique Variable Structure Control with Sliding Mode (VSC-SM) for fault accommodation in power providing systems of aircrafts propulsion. For that, it was used a mathematical model of a flight Simulator of a Quansers helicopter, named as 3-DOF Helicopter, which is an excellent module for teaching and development of control techniques. The results obtained in digital simulations show great performance of the system in fault when controlled by VSC-SM.
Célia Reis, FEIS/UNESP, Brazil - Neusa Silva, UNESP, Brazil.
Abstract. This not deals whit the problem of extrema which may occur in the step-response of a stable linear system with real zeros and poles. Some simple sufficient conditions are presented for analyses when zeros located between the dominant and fasted pole not cause extrema in the step-response. These conditions require knowledge of the pole-zero configuration of the corresponding transfer-function.
Fábio Chavarette, Universidade Estadual Paulista "Julio de Mesquita Filho", Brazil - José Balthazar, UNESP, Brazil - Ivan Guilherme, Unesp, Brazil - Luciano Barbanti, Unesp Ilha Solteira, Brazil.
Abstract. In this paper, we have studied the plasmatic membrane behavior using an electric circuit developed by Hodgkin and Huxley in 1952 and have dealt with the variation of the amount of time related to the potassium and sodium conductances in the squid axon. Recently, an irregular chaotic movement of the action potential of the membrane was observed for a number of techniques of control with the objective to stabilize the variation of this potential. This paper analyzes the non-linear dynamics of the HodgkinHuxley mathematical model, and we also developed an optimal linear control design based an particle swam optimization for the action potential of membranes.
HKeila SchneiderH, HPaulo SausenH, HAiram SausenH, Universidade Regional do Noroeste do Estado do RGS (UNIJUI)
Marcelo Savi, Univ Federal do Rio de Janeiro, Brazil.
Abstract. The observation of climate system allows one to identify two distinct phenomena related to the system evolution: climate change, usually related to human activities, and climate variability, usually associated with natural causes. Global warming is related to climate change and may be understood as the observed increase of the average temperature of the Earth. The primary cause of this phenomenon is the release of the greenhouse gases by burning of fossil fuels, land cleaning, agriculture, among others, leading to the increase of the so-called greenhouse effect. This important phenomenon can be analyzed by a nonlinear dynamics perspective and approach to deal with this problem is the time series analysis. In this regard, different techniques can be applied to evaluate the global warming dynamics. This kind of analysis allows one to make better predictions increasing our comprehension of the phenomenon. This article applies nonlinear tools to analyze temperature time series establishing state space reconstruction and prediction. Since noise contamination is unavoidable in data acquisition, it is important to employ robust techniques. The method of delay coordinates is employed for state space reconstruction and delay parameters are evaluated using the method of average mutual information and the method of false nearest neighbors. Afterwards, the simple nonlinear prediction method is employed to estimate temperatures of the future. Temperature time series from different places of the planet are used. Initially, the approach is verified considering known parts of the time series and afterwards, results are extrapolated for future values estimating temperature until 2028. Results show that these techniques are interesting in order to estimate the temperature evaluation presenting coherent estimations.
Sergio Moller, Universidade Federal do Rio Grande do Sul, Brazil.
Abstract. The classical analysis of experimental data considers stationary ergodic processes, but can not deal with phenomena which average values vary over time. Modern literature presents the wavelet analysis (wavelets) as a suitable technique to deal with time varying series, non stationary processes, transients and discontinuities. In this lecture, the wavelet analysis of experimental results of velocity and velocity fluctuations in some unsteady and transient laboratory turbulent flows is presented. The experimental technique using hot wires and flow visualizations is presented. Some fundamentals of wavelet analysis are discussed and compared with the classical Fourier analysis. Chosen flows are the accelerating and stationary wakes on cylinders and a prism, and the bistable flow on two cylinders or after rows of cylinders. Results show that most of the studied flows are non stationary. The use of wavelets along with flow visualizations improves the interpretation of hot wires measurements.
Peter Frick, Institute of Continuous Media, Algeria.
Abstract. The minicourse gives a short introduction and a review on recent developments in shell models of fully developed turbulence. The shell models were introduced in the 1970s as an attempt to mimic the Navier-Stokes equations via dynamical systems with limited degrees of freedom. They are constructed by truncations of the Navier-Stokes equations in the Fourier space, retaining only one real or complex mode as a representative of all the modes in the given spectral shell. In spite of the obvious fact that shell models give only a simplified description of turbulence, they appear to be a reasonable tool in turbulent studies. The contents of the course: 1. History - 2. Shell models for Navier-Stockes turbulence - 3. Shell models for MHD-turbulence - 4. Shell-models for helical turbulence - 5. The grid-shell approach - 6. Example - a combined multiscale model for Galactic dynamo.
Félix Mora-Camino, Ecole Nationale de l'Aviation Civile, France.
Abstract. This lecture introduces the flatness property for non linear differential systems and explains how to identify and apply this concept in the design of effective control systems. Contents (3 hours): - Introduction to non linear systems - Definition of differential flatness - Examples - Properties of differential flat systems - Non linear control of differential flat systems o Application to underactuated systems o Application to trajectory tracking o Robustness issues - Fault detection and identification for differential flat systems - Applications in aeronautics - Perspectives
Reyolando Brasil, University of São Paulo, Brazil.
Abstract. It is well known that earthquakes in Brazil are in little number and of small intensity. Nevertheless it is important for the Brazilian structural engineer to be able to participate in projects in Latin American countries of the Pacific Coast where the seismic problem is of great importance. In this lecture we review the basic ideas of seismic analysis as well as the National Codes of some of these countries
André Livorati, UNESP - Rio Claro, Brasil, Brazil.
Abstract. This study is addressed to chaotic dynamics of a family of stadium--like billiards with parabolic focusing components. The behavior of this model is described by application of a two-dimensional nonlinear map. A critical values of billiard parameters which correspond to a sudden change of the maximal Lyapunov exponent is found. It is shown that, in general, parameters of this billiard family, the width and the length of neutral components, are geometric invariants such that the maximal Lyapunov exponent has a scalling behavior with respect to the billiard geometry.
Juliano de Oliveira, UNESP-IGCE, Brazil.
Abstract. The transition from integrability to non-integrability for a two dimensional Hamiltonian mapping exhibiting mixed phase space is considered. The phase space of such mapping show a large chaotic sea surrounding KAM islands and limited by a set of invariant tori. The description of the phase transition is made by the use of scaling functions for average quantities of the mapping averaged along the chaotic sea. The critical exponents are obtained via extensive numerical simulations. Given the mapping the critical exponents that characterize the scaling functions are obtained. Therefore classes of universality are defined.
Diego Fregolente Mendes de Oliveira, Edson Denis Leonel, Universidade Estadual Paulista, Brazil.
Abstract. Some dynamical properties for a two dimensional time dependent oval billiard are studied under scaling description. The model is described by using a four dimensional nonlinear. Our results shows that the phase space has a mixed structure with invariant spanning curves limiting the size of the chaotic sea. We describe the chaotic regime below the first invariant spanning curve and show that it is scaling invariant.
Francys Souza, Lucas Eduardo Azevedo Simões, Mario Roberto da Silva, Edson Denis Leonel, Universidade Estadual Paulista, Brazil.
Abstract. Neste trabalho procuramos descrever e mapear, uma variação de um modelo conhecido como modelo Fermi- Ulam com uma força externa do tipo biela-manivela. Consideraremos uma dissipação, introduzida por meio de choques inelásticos da partícula tanto com a parede móvel quanto com a parede fixa. Isso faz com que existam dois coeficientes de restituição \alpha, \beta \in [0, 1] onde \alpha é o coeficiente de restituição dos choques da partícula com a parede móvel e \betha é da parede fixa. Buscamos também entender e descrever o comportamento da dinâmica do modelo em um regime de alta dissipação. Investigamos um fenômeno conhecido como cascata de bifurcações na tentativa de verificar se esse modelo obedece a mesma relação de convergência encontrada por Mitchell Feigenbaum para o mapa logístico.
Tiago Kroetz, ITA Departamento de Física, Brazil, Marisa Roberto, ITA, Brazil, Iberê Luiz Caldas, Instituto de Física da USP, Brazil.
Abstract. The bouncing ball problem consists of a particle under action of a uniform gravitational field which suffers repeated inelastic impacts on a sinusoidally vibrating plate at the floor. This simple unidimensional problem exhibits very rich dynamics, such as: period-doubling route to chaos, coexistence of many periodic and chaotic attractors, crisis and Fermi acceleration. In this work it was investigated the multistability of attractors considering a weak dissipation regime. Poincaré maps were obtained for the conservative case and as the system becomes gradually dissipative the behavior of the KAM islands were also analyzed. The basins of attraction and bifurcation diagrams for some values of dissipation parameter provide physical analyses which allow us to explain the coexistence of chaotic and periodic attractors.
Maria Espindola, Universidade Federal da Paraíba, Brazil.
Abstract. A new procedure named direct Hamiltonization gives another foundations to Analytical Mechanics, since in this formalism of the Hamiltonian Mechanics the Hamiltonian function can be obtained for all mechanical systems. The principal change proposed in this procedure is that the conjugate momenta cannot be defined a priori, but instead of this, they are determinate as a consequence of a canonical description of the mechanical system. As the direct Hamiltonization contains the alternative one, then the usual Hamiltonization and momenta is recovered while the envelope solution is selected. Also this procedure assures the existence of a Hamiltonian function without any constraints for any mechanical system therefore the usual quantization is always allowed.
Julio Claeyssen, Universidade Federal do Rio Grande do Sul, Brazil.
Abstract. The atomic force microscope (AFM) since its conception has been used for imaging the surface topography of conductors, insulators and, more recently, in nanotechnology due to high-resolution capabilities. The sharp tip attached to a cantilever at the free end plays an important role in AFM measurements due to its interaction with a sample in contact mode. This is a very complex mechanism and there is a growing interest in studying the vibration responses of an AFM cantilever. Here we considered the flexural vibration response of an AFM device using Timoshenko beam theory. The conical tip interacts with the sample through springs for normal and lateral displacements. The reponse due to a fixed end is characterized in terms of a fundamental matrix response and its derivative. The natural frequencies and modes are then determined through dynamic boundary conditions at the free end.
Luciano Barbanti, UNESP, Brazil.
Abstract. The concept of Riemann-Stieltjes integral in R, was already defined in the field of calculus on time scales. Due to inherent difficulties in the Riemann-Stieltjes definition when dealing with common discontinuities, this concept was extended to the so called odd-meshed Riemann-Stieltjes integral, avoiding in this way most of these difficulties. Here we extend the odd-meshed Riemann-Stieltjes integral for general Banach spaces and define the linear Volterra Stieltjes integral equations with this kind of integrals, presenting some applications for phenomenon which discontinuities.
Mario Lincoln de Carlos Etchebehere, UNESP, Brazil.
Abstract. Paleoseismology: Usefulness of the quaternary geological record in the western São Paulo State plateau Southeastern Brazil.
Luciano Menegaldo, Instituto Militar de Engenharia, Brazil.
Abstract. Biomechanical modeling of the human musculoskeletal system requires the gathering of several different scientific disciplines, including neurophysiology, anatomy, multi-body dynamics, control theory, among others. This invited lecture paper will address some results of the authors last years of research in this field in collaboration with his colleagues, showing some results in muscle modeling and its experimental validation, as well as posture biomechanics and optimal control.
Saulo M. Barros, USP, Brazil, Pedro Peixoto, Universidade de São Paulo, Brazil.
Abstract. We consider harmonic wavelet-Galerkin methods for the solution of partial differential equations. Several variants of the method are proposed and analyzed, using the Burgers equation as a test model. Computational complexity can be reduced when the localization properties of the wavelets and restricted interactions between different scales are exploited. The resulting variants of the method have computational complexities ranging from O(N3) to O(N) (N being the space dimension) per time-step. A pseudo-spectral wavelet scheme is also described and compared to the methods based on connection coefficients. The harmonic wavelet-Galerkin scheme is applied to a non-linear model for the propagation of precipitation fronts, with the front locations being exposed in the sizes of the localized wavelet coefficients.
Peter Frick, Institute of Continuous Media, Algeria, Rodion Stepanov, Institute of Continuos Media Mechanics of Ural, Russia, Dmitry Sokoloff, Moscow State University, Russia.
Abstract. Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requires the definition of complex polarized intensity in the wavelength range $-\\infty < \\infty$. The problem is that the measurements at negative $\\lambda^2$ are not possible. We introduce a simple method for continuation of the observed complex polarized intensity $P(\\lambda^2)$ into the domain $\\lambda^2
Peter Frick, Institute of Continuous Media, Algeria, Rodion Stepanov, Institute of Continuos Media Mechanics of Ural, Russia, Sergey Podtaev, Andrew Dumler, Perm State University, Russia.
Abstract. Up-to-date bioimpedancometric methods offer a wide spectrum of data that can be used for complex analysis of cardiovascular system state. Still, the use of appropriate mathematical approaches for data processing and calculation of main parameters is essential for confident diagnosis. The data processing problems are mainly connected with unavoidable noise sources, device noises, necessity to differentiate the registered data, pattern recognition of the structures responsible for specific fragments of the heart cycle and for the integral characteristics. In this work wavelet analysis is offered to resolve the various upcoming problems. Approaches based on decomposition of the analysed signal on the base of special functions - wavelets - allow filtration of noises, artefacts and trends caused by side processes. They offer a wide spectrum of spectral and correlation analyses of synchronously recorded signals (for polyrheocardiograf those are impedance signals, cardiogram and phonocardiogram). Wavelet decomposition allows to distinguishe high-frequency device noise from low-frequency variations caused by breathing, for example. Use of original wavelet differentiation algorithms allow to combine filtration and calculation of the derivatives of rheocardiogram. Time-spectral representation of the data on the surface forms the wavelet-portrait that gives images with relief markers of cardiac cycle phases. Utilization of the offered mathematical method raises the self-descriptiveness of impedancometric examination of cardiovascular system and makes more accurate the definition of traditional hemodynamic parameters.
Sérgio de Oliveira, Luciano Menegaldo, Instituto Militar de Engenharia, Brazil.
Abstract. This paper presents results in a recursive computational implementation, based on Jategoankar [1], to simulate and identify helicopter stability and control derivatives. It discusses the range of Bayesian and Optimization algorithm in a Output Error Method, applying a Gauss-Newton algorithm implementation.
Denilson Paulo Santos, Antonio Prado, INPE, Brazil.
Abstract. The spacecraft propulsion system have passed for diverse evolutions, leaving combustion engines and arriving at ion propulsion. The necessity of more efficient rockets stimulated the research in this scope. In this work ∆V will be analyzed proceeding from an electric propellant acting in set with gravitational maneuvers. The optimization of maneuvers will be approached in interplanetary missions using solar electric propulsion and Gravity Assisted Maneuver attended to reduce the costs of the mission. The high specific impulse of electric propulsion makes a Gravity Assisted Maneuver 1 year after departure convenient. Missions for several Near Earth Asteroids will be considered. The analysis suggests criteria for the definition of initial solutions demanded for the process of optimization of trajectories. Trajectories for the asteroid 19989UQ are analyzed. Direct trajectories, trajectories with 1 gravity assisted from the Earth and with 2 gravity assisted from the Earth and either Venus are present. An indirect optimization method will be used in the simulations.
Leonardo Santos, INPE - Instituto Nacional de Pesquisas Espaciais, Brazil, Leonardo Chiwiacowsky, Universidade do Vale do Rio dos Sinos - UNISINOS, Brazil, Haroldo Campos Velho, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. Uma análise de robustez de um novo método (método híbrido) para estimação de dano em estruturas é apresentada. Os testes são realizados na detecção de danos em uma barra, discretizada em elementos finitos.
José Márcio Pereira Figueira, Grupo Especial de Ensaios em voo, Brazil, Ronaldo Cruz, Grupo Especial de Ensaios em Voo, Brazil, Donizeti de Andrade, Instituto Tecnologico de Aeronautica, Brazil.
Abstract. This paper presents analyses of the effect of the positive pitch-flap coupling (negative d3) on the flapping response of an articulated tail rotor blade with geometric parameters similar to the AS355 Twin-Engine Squirrel helicopter.
Vinícius Piccirillo, ITA - Tecnological Institute of Aeronautics, Brazil.
Abstract. This paper concerns the application of a Model Predictive Control (MPC) technique to a helicopter blade-sailing system in the presence of unsteady flow effects. The aeroservoelastic analysis focuses on the performance of a proposed individual blade-root controller (IBRC) with respect to the reduction of blade flapping vibrations in articulated rotors during engagement shipboard operations. The simulation results show that the proposed aeroelastic controller can yield tunnel-strike suppression without actuator saturation.
Carlos Corteline, ITA, Brazil.
Abstract. This work is a study of the effects of air in hydraulic control system. The study is based on models of: the mixture of air with hydraulic fluid, the servo hydraulic control system and experimental identification. The air mixture model is to evaluate the impact on the fluid properties, the hydraulic systems one is to assess the impact of changes in the fluid properties in the system performance and identification to estimate the amount of air in the system.
Kleber Augusto Castão, ITA - Technologial Institute of Aeronautics, Brazil, Luiz Carlos Sandoval Goes, Instituto Tecnologico de Aeronautica, Brazil, José M. Balthazar, UNESP, Brazil, Roberto Luiz da Cunha Barroso Ramos, UFABC-Universidade Federal do ABC, Brazil.
Abstract. This paper analyzes the response of a helicopter blade-sailing under effect of a Magnetorheological Damper (MRD) in the presence of unsteady flow effects. The aeroelastic analysis focuses on the performance of a semi active control device with respect to the reduction of blade flapping vibrations in hingelles rotors during engagement shipboard operations.
Carlos Constantino, Aeronautics Institute of Technology, Brazil, Luiz Carlos Sandoval Goes, Instituto Tecnologico de Aeronautica, Brazil, Fernando Moreira, Embraer, Brazil.
Abstract. The objective of this work was to develop a high fidelity model representative on high frequencies of a FCS with an active-active hydraulic actuation. The performance for step input and frequency response were analyzed, showing to be a model close to a real system and representative even in high frequencies.
Jose Ricardo Sturaro, UNESP, Brazil., Jose Silvio Govone, IGCE-Unesp, Brazil.
Abstract. A aplicação de métodos ou modelos numéricos em Geociências tem aumentado consideravelmente nas ultimas décadas.Isto se deve ao fato prático do avanço extraordinário da informática que possibilitou o processamento de grande quantidade de informações, comumente encontrada como resultados dos fenômenos em Geociências. Tendo em vista, que estes resultados não se adequam aos modelos determinísticos, recorreu-se aos fundamentos das variáveis aleatórias, cujo processamento intenso, possibilita obter um dos alvos mais importantes da Geociências, que são as estimativas em locais náo amostrados. Dentro deste contexto, destacam-se os métodos estatisticos e geoestatisticos ou, ainda, modelos numéricos determinísticos, porém conduzidos pelos procedimentos estocásticos
Anthony Lui, JHU/APL, USA.
Abstract. A major disturbance in the near-Earth space is a substorm, which is manifested in dynamic auroral displays at the Earth''s polar region with intense charged particle enhancements in the Earth''s radiation belts. A strong electric current system known as substorm current wedge develops also during substorms. It is generally perceived that electric current flowing in the Earth''s magnetic environment, known as the magnetosphere, becomes diverted into the ionosphere by a plasma process in space. The space disturbance associated with this electric current diversion is called current disruption. In this paper, we report how wavelet analysis of the magnetic and electric fields observed in current disruptions, coupled with basic Maxwell''s equation governing electromagnetic wave parameters, can be used to identify the physical process responsible for the current disruption phenomenon. The electromagnetic waves excited initially are found to be obliquely propagating ion cyclotron waves, which are consistent with the activation of a kinetic plasma instability and inconsistent with fluid-like plasma processes.
Guillermo Adrián Stenborg, Interferometrics, Inc., USA.
Abstract. Our knowledge of the structure and dynamics of the solar corona has greatly increased over the last 15 years thanks to the observations from the imaging telescopes on board the Solar and Heliospheric Observatory (SOHO) and most recently the Solar Terrestrial Relationships Observatory (STEREO). In particular, the Extreme-ultraviolet Imaging Telescope (EIT) onboard SOHO and the Extreme Ultraviolet Imaging (EUVI) telescopes in the SECCHI instrument suite on the STEREO mission have provided (and continues to provide) the solar physics community with an unprecedented view of the extreme ultraviolet solar transition region and corona. They have observed many different types of solar features both "quiescent" and dynamic. It would be natural to think that, by now, these instruments have exhausted their discovery potential. However, the multi-scale nature of the observed solar features is far from being fully exploited. We have developed a wavelet-based technique that exploits the multi-scale nature of the solar features to clean the images and enhance the solar features observed with such instruments. The method implemented employs a multi-level decomposition scheme (splitting algorithm of a wavelet packet on non-orthogonal wavelets) via the à trous wavelet transform, local noise reduction, and interactive weighted recomposition. The processed images reveal such a wealth of structures and dynamics that they seem to have been obtained by a new set of instruments. The clarity of the enhanced images allows us to identify numerous and potentially interesting phenomena that were previously obscured by a background level that included stray light and image noise. After a brief survey of the different kinds of solar data mentioned above, and disclose the difficulties the scientist must deal to analyze them, we will introduce the technique developed, show its performance, and make explicit how it contributes to the understanding of the mechanisms at work in the Suns atmosphere.
Danuta Sado, Warsaw University of Technology, Poland.
Abstract. This work draws attention to the analysis of a dynamics of a three-degree-of-freedom autoparametric system with two pendulums connected by a SMA (Shape Memory Alloy) spring in the neighbourhood of inertial and external resonance. The system consists of the body of mass m1, which is hung on a spring and damper, and two pendulums of the length l and masses m2 and m3 mounted to the body of mass m1 and connected by a SMA spring. The body of mass m1 is subjected to vertical excitation while one of the pendulums is excited in the horizontal direction. A polynomial model is assumed to describe the behavior of the shape memory element. The equations of motion have been solved numerically and there was studied the influence of temperature on the energy transfer between the modes of vibration. Solutions for the system response are presented for specific values of the parameters of the system. It was shown that in this type of system one mode of vibration might excite or damp another mode, and that except different kinds of periodic vibration there may also appear chaotic vibration.
Edson Denis Leonel, DEMAC, Brazil.
Abstract. We consider a dissipative oval-like shaped billiard with a periodically moving boundary. The dissipation considered is proportional to a power of the velocity V of the particle. The three specific types of power laws used are: (i) F\propto -V; (ii) F\propto -V^2 and (iii) F\propto -V^\delta with 1<\delta<\delta. In the course of the dynamics of the particle, if a large initial velocity is considered, case (i) shows that the decay of the particle's velocity is a linear function of the number of collisions with the boundary. For case (ii), an exponential decay is observed, and for 1<\delta<2, an power-like decay is observed. Scaling laws were used to characterize a phase transition from limited to unlimited energy gain for case (ii). The critical exponents obtained for the phase transition are the same as those obtained for the dissipative bouncer model. Therefore near this phase transition, these two rather different models belong to the same class of universality. For all types of dissipation, the results obtained allow us to conclude that suppression of the unlimited energy growth is indeed observed.
Luiz Felipe Turci, INPE, Brazil, Elbert E. N. Macau, Instituto Nacional de Pesquisas Espaciais, Brazil.
Abstract. Pinning control techniques have been effectively applied for the synchronization of complex networks. In this work we proposed two different hybrid pinning control strategies that guarantee not only the synchronization of the entire network but the synchronization onto a known desired solution.
Berenice Damasceno, UNESP, Brazil.
Abstract. It is well known the classical Markowitz Theory for portfolio management and balance. Despite this, it is possible to improve the efficiency in the model, if we introduce some other concepts for the risk measurement different than the usual standard deviation formula. Notice that Markowitz itself proposed another measures for risk, as for instance the named semi-variation. Here we propose and discuss some of these new concepts on risk and compare ones against the others.
Samir Daud, Carlos Ribeiro, ITA, Brazil.
Abstract. Natural Language Requirements are widely used in the aerospace industry, at least as the first level of description of a system. This paper compares some approaches in lexical analyses as a part of natural language processing applied to the analysis of requirements.
Emilia Balthazar, Faculdade de Ciências Farmacêuticas de Araraquara - UNESP, Brazil, Maria Rita Oliveira, IB-Unesp, departamento de Educação, Brazil, José Sílvio Govone, UNESP, Brazil.
Abstract. The reference curves for body mass index (BMI) have been presented in percentiles and z-scores and interpreted according to different cut-off points for the classification of the nutritional status of children. In this longitudinal study, the data are presented under three classification criteria.
Rita de Cássia Martins, Faculdades Adamantinenses Integradas, Brazil, José Eduardo Corrente, IB - UNEP, Brazil, Ana Paula Vioto, FCF - UNESP, Brazil, Emilia Balthazar, Faculdade de Ciências Farmacêuticas de Araraquara - UNESP, Brazil, Maria Rita Oliveira, IB-UNESP, departamento de Educação, Brazil.
Abstract. The reference curves for body mass index (BMI) have been presented in percentiles and z-scores and interpreted according to different cut-off points for the classification of the nutritional status of children. In this longitudinal study, the data are presented under three classification criteria.
Noa Prada Souza, Patrícia Souza Novaes, Universidade Estadual Paulista, Brazil, Irineu Rasera Junior, FACULDADE DE MEDICINA DA UNESP BOTUCATU, Brazil, Cláudia Rucco Penteado Detregiachi, Déborah de Oliveira, Universidade Estadual Paulista, Brazil, Maria Rita Oliveira, IB-UNESP, departamento de Educação, Brazil.
Abstract. Of the set of American and Canadian references, the Estimated Average Requirement (EAR), which represents the median intake of a reference population, was taken as the cut-off point for the assessment of the adequacy of individual nutrient intake in women who have undergone or will undergo obesity surgery.
Lilian Galesi, Universidade Estadual Paulista, Brazil, Juliana Campos, Universidade Estadual Paulista "Júlio de Mesquita Filho", Brazil, José Eduardo Corrente, IB - Unesp, Brazil, Maria Rita Oliveira, IB-Unesp, departamento de Educação, Brazil.
Abstract. A nutritional screening instrument to be used by laypersons who provide care for elderly individuals was established. The temporary data indicate that the instrument has reproducibility and appropriate internal consistency. If the instrument does not lose its good characteristics after factor analysis, the instrument development was successful.
Karina Rodrigues Quesada, Universidade Estadual Paulista, Brazil, Kelly Cristina Pagoto Fogaça, UNIMEP, Brazil, Irineu Rasera Junior, FACULDADE DE MEDICINA DA UNESP BOTUCATU, Brazil, Ana Paula C Martinez, UNIMEP, Brazil, Cláudia Rucco Penteado Detregiachi, Universidade Estadual Paulista, Brazil, Maria Rita Oliveira, IB-Unesp, departamento de Educação, Brazil.
Abstract. The Resting Energy Expenditure (REE) assessed by indirect calorimetry of women who have undergone obesity surgery was compared with data estimated by predictive equations, while the estimated energy needs (NE) were confronted with energy intake (EIrel) and the correlation of the ratio EIrep/REE with energy spent on activities was investigated.
José Raimundo de Souza Passos, Departamento de Bioestatística/IB, Universidade Estadual Paulista, Laécio Carvalho de Barros Departamento de Matemática Aplicada/ IMECC/UNICAMP.
Abstract. The Lotka-Volterra predator prey model has been extensively used to describe the relationship between species, and, as a consequence, quite a variety of dynamical biological systems have been related to it. In this work, we study the stability of the Lotka-Volterra model with logistic growth of prey. The mathematical approach is designed to study the relationships between the parameters and the system behavior. The main idea is to study the effect on the stability by changes in the parameters values by random perturbations and fuzzy sets. The method proposed assuming that the carry capacity can be a fuzzy set, a crisp set or a Weibull random variable. The others parameters are assuming uniform random variables. The results shows that the Lotka-Volterra system with the logistic prey growth, can present stable node, independent the parameter combination. The percentage of stable spiral growth asymptotically to 98% with the values of carry capacity, for all approaches suggested
Marcos Quiles, Federal University of Sao Paulo, Brazil, Liang Zhao, Fabricio Breve, Universidade de São Paulo, Brazil.
Abstract. One salient feature of complex networks is the presence of communities, or groups of densely connected nodes. Community detection can not only help to understand the topological structure of complex networks, but also provide new techniques for real applications, such as data mining. In this paper, we propose a new model for community detection by using the synchronization and desynchronization property emerged from a network of Integrate and Fire neurons. This model has been applied to artificial and real-world networks and good results are obtained.
Ricardo Egydio de Carvalho, UNESP/Rio Calro, Brazil.
Abstract. The non-twist standard map occurs frequently in many fields of science specially in modeling the dynamics of the magnetic field lines in tokamaks. Robust tori, dynamical barriers that impede the radial transport among different regions of the phase space, are introduced in the non-twist standard map in a conservative fashion. The resulting Non-Twist Standard Map with Robust Tori (NTRT) is an improved model to study transport barriers in plasmas confined in tokamaks. .
Helio Pedrini, Universidade Estadual de Campinas, Brazil.
Abstract. The advance of computer-based technology during the last decades has contributed to the expansion of several scientific applications. Powerful computer systems, associated with efficient algorithms, are now capable of producing data representations with high degree of detail. Examples of applications involving large volumes of data and complex domain knowledge include remote sensing, planetary exploration, computer vision, computer-aided design, medical image analysis, and content-based video retrieval. Wavelet transforms have been used for image analysis mainly due to their capability of providing information in both spatial and frequency domains, multi-scale representation, and flexibility. This minisymposium presents theoretical and practical aspects of wavelet transforms for image analysis with applications in image segmentation, compression, denoising and watermarking.