Long-wave and short-wave asymptotics in nonlinear dispersive systems

In this paper we study the interplay between short- and long-space scales in the context of conservative dispersive systems. We consider model systems in (1 + 1) dimensions that admit both long- and short-wavelength solutions in the linear regime. A nonlinear analysis of these systems is constructed, making use of multiscale expansions. We show that the equations governing the lowest order involve only short-wave properties and that the long-wave effects to leading order are determined by a secularity elimination procedure. © 1999 The American Physical Society.

Stabilizing controller design for uncertain nonlinear systems using fuzzy models

A Lyapunov-based stabilizing control design method for uncertain nonlinear dynamical systems using fuzzy models is proposed. The controller is constructed using a design model of the dynamical process to be controlled. The design model is obtained from the truth model using a fuzzy modeling approach. The truth model represents a detailed description of the process dynamics. The truth model is used in a simulation experiment to evaluate the performance of the controller design. A method for generating local models that constitute the design model is proposed. Sufficient conditions for stability and stabilizability of fuzzy models using fuzzy state-feedback controllers are given. The results obtained are illustrated with a numerical example involving a four-dimensional nonlinear model of a stick balancer.

Nonlinear (2+1)-dimensional systems solvable through asymptotic modules

Some nonlinear differential systems in (2+1) dimensions are characterized by means of asymptotic modules involving two poles and a ring of linear differential operators with scalar coefficients.Rational and soliton-like are exhibited. If these coefficients are rational functions, the formalism leads to nonlinear evolution equations with constraints. © 1989.

Optimal linear and nonlinear control design for chaotic systems

In this work, the linear and nonlinear feedback control techniques for chaotic systems were been considered. The optimal nonlinear control design problem has been resolved by using Dynamic Programming that reduced this problem to a solution of the Hamilton-Jacobi-Bellman equation. In present work the linear feedback control problem has been reformulated under optimal control theory viewpoint. The formulated Theorem expresses explicitly the form of minimized functional and gives the sufficient conditions that allow using the linear feedback control for nonlinear system. The numerical simulations for the Rössler system and the Duffing oscillator are provided to show the effectiveness of this method. Copyright © 2005 by ASME.

Remarks on an Optimal Linear Control Design Applied to a Nonideal and an Ideal Structure Coupled to an Essentially Nonlinear Oscillator

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On Nonlinear Dynamics and Control of A Particular Portal Frame Foundation Model, Excited by a Non-Ideal Motor

The nonlinear dynamic response and a nonlinear control method of a particular portal frame foundation for an unbalanced rotating machine with limited power (non-ideal motor) are examined. Numerical simulations are performed for a set of control parameters (depending on the voltage of the motor) related to the static and dynamic characteristics of the motor. The interaction of the structure with the excitation source may lead to the occurrence of interesting phenomena during the forward passage through the several resonance states of the systems. A mathematical model having two degrees of freedom simplifies the non-ideal system. The study of controlling steady-state vibrations of the non-ideal system is based on the saturation phenomenon due to internal resonance.

A maximum principle for infinite time asymptotically stable impulsive dynamic control systems

We consider an infinite horizon optimal impulsive control problems for which a given cost function is minimized by choosing control strategies driving the state to a point in a given closed set C ∞. We present necessary conditions of optimality in the form of a maximum principle for which the boundary condition of the adjoint variable is such that non-degeneracy due to the fact that the time horizon is infinite is ensured. These conditions are given for conventional systems in a first instance and then for impulsive control problems. They are proved by considering a family of approximating auxiliary interval conventional (without impulses) optimal control problems defined on an increasing sequence of finite time intervals. As far as we know, results of this kind have not been derived previously. © 2010 IFAC.

Genetic associations of visual scores with subsequent rebreeding and days to first calving in Nellore cattle

Records of Nellore animals born from 1990 to 2006 were used to estimate genetic correlations of visual scores at yearling (conformation, C; finishing precocity, P; and muscling, M) with primiparous subsequent rebreeding (SR) and days to first calving (DC), because the magnitude of these associations is still unknown. Genetic parameters were estimated by multiple-traits Bayesian analysis, using a nonlinear (threshold) animal models for visual scores and SR and a linear animal models for weaning weight (WW) and DC. WW was included in the analysis to account for the effects of sequential selection. The posterior means of heritabilities estimated for C, P, M, SR and DC were 0.24 +/- 0.01, 0.31 +/- 0.01, 0.30 +/- 0.01, 0.18 +/- 0.02 and 0.06 +/- 0.02, respectively. The posterior means of genetic correlations estimated between SR and visual scores were low and positive, with values of 0.09 +/- 0.02 (C), 0.19 +/- 0.03 (P) and 0.18 +/- 0.05 (M). on the other hand, negative genetic correlations were found between DC and C (-0.11 +/- 0.09), P (-0.19 +/- 0.09) and M (-0.16 +/- 0.09). The primiparous rebreeding trait has genetic variability in Nellore cattle. The genetic correlations between visual scores, and SR and DC were low and favourable. The genetic changes in C, P and M were 0.02, 0.03 and 0.03/year, respectively. For SR and DC, genetic trends were 0.01/year and -0.01 days/year, respectively, indicating that the increase in genetic merit for reproductive traits was small over time. Direct selection for visual scores together with female reproductive traits is recommended to increase the fertility of beef cows.

Genetic associations of sexual precocity with growth traits and visual scores of conformation, finishing, and muscling in Nelore cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic parameters and relationships between heifers rebreeding and hip height in Nellore cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genetic associations of conformation, finishing precocity and muscling visual scores with mature weight in Nelore cattle

Were estimate (co)variance and genetic associations between conformation, finishing precocity and muscling visual scores measured at weaning (SCW, SFW and SMW, respectively) and yearling (SCY. SFY and SMY, respectively) with mature weight (MW) in Nelore cows, in order to predict the possible changes that inclusion of visual scores in beef cattle selection indices would bring to female mature weight. The data set contained records of 36,757 females, born between 1993 and 2006, belonging to the Jacarezinho cattle raising farm. (Co)variance components were estimated by bivariate animal models using Bayesian inference method through Gibbs sampling, assuming a linear model for MW and a nonlinear (threshold) model for conformation, finishing precocity and muscling visual scores. The first 10,000 rounds were considered as the burn-in period and discarded. The posterior means of direct heritability distributions were: 0.16 +/- 0.02 (SCW); 0.20 +/- 0.02 (SFW); 0.19 +/- 0.02 (SMW); 0.24 +/- 0.02 (SCY); 0.31 +/- 0.02 (SFY); 0.32 +/- 0.02 (SMY) and 0.46 +/- 0.04 (MW). Estimates of genetic correlations between visual scores and MW were positive and moderate, ranging from 0.27 +/- 0.06 to 0.36 +/- 0.04. Visual scores and MW should respond favorably to direct selection. Mature weight can be used in Nelore breeding programs designed to monitor the cows' size. Selection of animals with higher conformation, finishing precocity and muscling scores, especially at yearling, should promote an increase in cows' mature weight. (c) 2010 Elsevier B.V. All rights reserved.

Correlações genéticas entre escores visuais e características reprodutivas em bovinos Nelore usando inferência bayesiana

O objetivo deste trabalho foi estimar a herdabilidade e as correlações genéticas entre escores visuais e características reprodutivas de animais da raça Nelore. As características avaliadas foram: precocidade, musculatura, e escores de conformação à desmama (PD, MD e CD, respectivamente) e ao sobreano (PS, MS e CS, respectivamente); idade ao primeiro parto (IPP); e perímetro escrotal (PE). Foram utilizadas informações de 66.244 animais, nascidos entre 1990 e 2006. Os parâmetros genéticos foram estimados em análises bicaracterísticas, com inferência bayesiana. Foi utilizado um modelo linear para IPP e PE, e um modelo não linear (threshold) para os escores visuais. As herdabilidades estimadas foram: CD, 0,19±0,02; PD, 0,23±0,02; MD, 0,20±0,02; CS, 0,26±0,01; PS, 0,33±0,02; MS, 0,32±0,02; IPP, 0,16±0,03; e PE, 0,36±0,02. As correlações genéticas estimadas entre os escores visuais e IPP foram negativas, de -0,18±0,03 a -0,29±0,02. Correlações genéticas positivas foram obtidas entre os escores visuais e o PE, de 0,19±0,01 a 0,31±0,01. A seleção de animais com os maiores escores visuais, principalmente ao sobreano, permite melhorar o desempenho reprodutivo dos rebanhos

Genetic parameters and relationships of heifer pregnancy and age at first calving with weight gain, yearling and mature weight in Nelore cattle

The objectives of the current study were to investigate the additive genetic associations between heifer pregnancy at 16 months of age (HP16) and age at first calving (AFC) with weight gain from birth to weaning (WG), yearling weight (YW) and mature weight (MW), in order to verify the possibility of using the traits measured directly in females as selection criteria for the genetic improvement of sexual precocity in Nelore cattle. (Co)variance components were estimated by Bayesian inference using a linear animal model for AFC, WG, YW and MW and a nonlinear (threshold) animal model for HP16. The posterior means of direct heritability estimates were: 0.45 +/- 0.02; 0.10 +/- 0.01; 023 +/- 0.02; 0.36 +/- 0.01 and 0.39 +/- 0.04, for HP16, AFC, WG, YW and MW, respectively. Maternal heritability estimate for WG was 0.07 +/- 0.01. Genetic correlations estimated between HP16 and WG, YW and MW were 0.19 +/- 0.04; 0.25 +/- 0.06 and 0.14 +/- 0.05, respectively. The genetic correlations of AFC with WG, YW and MW were low to moderate and negative, with values of -0.18 +/- 0.06; -0.22 +/- 0.05 and -0.12 +/- 0.05, respectively. The high heritability estimated for HP16 suggests that this trait seem to be a better selection criterion for females sexual precocity than AFC. Long-term selection for animals that are heavier at young ages tends to improve the heifers sexual precocity evaluated by HP16 or AFC. Predicted breeding values for HP16 can be used to select bulls and it can lead to an improvement in sexual precocity. The inclusion of HP16 in a selection index will result in small or no response for females mature weight. (C) 2011 Elsevier B.V. All rights reserved.

Genetic correlations between heifer subsequent rebreeding and age at first calving and growth traits in Nellore cattle by Bayesian inference

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transition to complete synchronization in phase-coupled oscillators with nearest neighbor coupling

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)