The method of steepest descent is used to minimize typical functionals from elasticity.

In this paper we consider the question of uniqueness of positive solutions for Dirichlet problems of the form - Δ u(x)= g(λ,u(x)) in B, u(x) = 0 on ϑB, where A is the Laplace operator, B is the unit ball in RˆN, and A>0. We show that if g(λ,u)=uˆ(N+2)/(N-2) + λ, that is g has "critical growth", then large positive solutions are unique. We also prove uniqueness of large solutions when g(λ,u)=A f(u) with f(0) < 0, f "superlinear" and monotone. We use a number of methods from nonlinear functional analysis such as variational identities, Sturm comparison theorems and methods of order. We also present a regularity result on linear elliptic equation where a coefficient has critical growth.

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Thesis (M. Eng.)--Carleton University, 1993. / Also available in electronic format on the Internet.

A nonlinear movmg contact algorithm has been implemented to model the sticking-sliding inelastic behavior in the interlocks of steel sheet pile sections subjected to axial tension. Previously, numerical instabilities were encountered during the solution process while conducting a series of verification problems for the algorithm by the Newton-Raphson method. In an attempt to identify the cause of these instabilities, an in-depth study of the effect of fineness of the finite element mesh on the convergence of the solution has been undertaken. The solution process credited to Riks and Wempner has been used to find the postbuckling equilibrium path of shallow reticulated domes. This algorithm, with some modifications, is used to move from one load step to another step in this study. As in most nonlinear problems, the size of the load step influences the rate of convergence. In addition, in the moving contact problem nodes can move along the sides of an element on the contact surface. Thus, the mesh refinement also affects the rate of convergence. To study the effects of both of these parameters, a series of test problems was run with variable load steps and mesh refinements. The modified Riks-Wempner algorithm, which automatically adjusts the load step size as the solution process advances, successfully solved all the inelastic and large displacement problems attempted. From the mesh refinement studies two conclusions were reached: for curved boundaries use curved elements and avoid the use of irregularly shaped elements. Finally, the improved solution algorithm is applied fo sheet pile interlocks loaded in axial tension. Results for progressively increasing load show the spread of yielding in the thumbs and fingers of the interlocks and the sliding of one past another as the deformations increase. / Master of Science

Orientador: Silvia Cristina Mangini Bocchi / Coorientador: Moacir Fernandes de Godoy / Banca: Aparecida Maria Catai / Banca: Wilza Carla Spiri / Resumo: Introdução. A demanda espontânea é considerada um problema na gestão dos serviços de atenção primária à saúde e na garantia do acesso oportuno. Adicionalmente, o Brasil passa por processo de transição demográfica e epidemiológica que modifica o uso dos serviços. Assim, a carga de morbimortalidade é deslocada dos grupos mais jovens para os mais idosos e a predominância da mortalidade dá lugar à morbidade. Desta maneira, esse estudo propõe: 1. Classificar e quantificar o padrão de comportamento da ocorrência das morbidades diagnosticadas nos atendimentos não agendados de idosos em uma Unidade de Saúde da Família; 2. Mostrar a adequação da análise não linear em fenômeno social humano. Método. Estudo de abordagem quantitativa, observacional, ecológico de tendência temporal. Utilizouse a Dinâmica Simbólica e a Quantificação da Recorrência para análise não linear das séries históricas (categórica e temporais) construídas. As morbidades identificadas no atendimento não agendado de idosos em uma unidade de saúde da família do interior paulista, no período de maio/2012 a maio/2014, foram convertidas em séries históricas. Resultados. A morbidade musculoesquelética apresenta uma tendência de comportamento aleatório, porém é a mais prevalente. A morbidade respiratória apresenta tendência de comportamento periódico, enquanto a morbidade circulatória e as crônicas prevalentes (hipertensão arterial sistêmica e diabetes mellitus) apresentam tendência caótica. A análise não linear demonstrou-se mais adequada que a estatística clássica na avaliação da dinâmica do fenômeno investigado / Abstract: Introduction. The unscheduled encounters represent a significant problem for primary care clinics management and to provide timely access. Additionally, Brazil has undergone a demographic and epidemiological transition process that modifies the use of health services. Thus, the burden of morbidity and mortality is shifted from younger to older groups and the prevalence of morbidity replaces mortality. We propose: 1. To classify the behavior pattern of morbidities diagnosed in the unplanned appointments resulting from the elderly in a service provider; 2. To show the adequacy of nonlinear analysis in human social phenomenon. Method. It is a quantitative research, observational, ecological design to temporal trend. We used the Symbolic Dynamic and Recurrence quantification analysis to analyze the time-series. The morbidities diagnosed in the unplanned appointments from elderly were transformed into time series. The data was collect in a Primary Care Unit locate in the country of São Paulo State, between May/2012 to May/2014. Results. Musculoskeletal discords has a tendency to random behavior, however, it is the most prevalent. The circulatory morbidity and prevalent chronic (Hypertension and Diabetes Mellitus) present chaotic trend and the linear respiratory diseases were linear. The nonlinear analysis was more appropriate than the classic statistic in assessing the dynamic of investigated phenomenon / Mestre

Orientador: João Mauricio Rosario / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-21T12:17:51Z (GMT). No. of bitstreams: 1 Hermini_HelderAnibal_M.pdf: 23638216 bytes, checksum: 10e5b83880a18ac1bd17625ea99de153 (MD5) Previous issue date: 1996 / Resumo: Este trabalho analisa a nível teórico e de simulação as Não-Linearidades presentes na modelagem e controle de robôs. Ao mesmo tempo é apresentado um estudo detalhado sobre sistemas Não-Lineares envolvendo o desenvolvimento de Controladores Não-Lineares para Manipuladores Industriais. As simulações são realizadas a partir do desenvolvimento do modelo dinâmico de manipuladores de até dois graus de liberdade, considerados rígidos, podendo ser futuramente estendidos a outros graus de liberdade e ao caso de manipuladores flexíveis. A partir dos resultados apresentados na simulação, pode-se mostrar vantagens e inconvenientes da utilização desses controladores em relação aos controladores tradicionais / Abstract: This work analyses the theory and simulation of Non-Linearitys found in the equations and robots control with one and two degrees of freedom. Simultaneously it is presented a detailed work on non linear system involving the development of Non Linear Controls for Industrial Manipulators. This process is moré advantageous than the classical linear controls. Extension to other related works including Flexible Manipulators are also Suggested. / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Thesis (D.Tech (Engineering Electrical)) - Central University of Technology, Free State, 2005 / When Thomas Edison invented his carbon filament lamp in 1879, gas shares fell overnight. A committee of inquiry was set up to examine the future possibilities of the new method of lighting, and had reached the conclusion that electric light in the home was fanciful and absurd. Today electric light burns in practically every house in the civilised world, with many great advances in the production and use of electricity and electric power supplied by various utilities. The objective of the electric utility to deliver pure sinusoidal voltage at fairly constant magnitude throughout their system is complicated by the fact that there are currently loads on the system that produce harmonic voltages, which result in distorted voltages and currents that can adversely impact on the system performance in different ways. Because the numbers of harmonic producing loads have increased over the years, it has become necessary to address their influence, when making any additions or changes to an installation. Quality of supply measurements have long been used to characterise non-linearity on the power system, and have traditionally been measured with expensive portable analysers. A potentially faster, more integrated, and more flexible solution to measure the harmonics with a Supervisory System is accomplished by this research. Any script which aspired to cover in full detail the whole field of a subject so enormous as techniques to measure the quality of electricity supply on a SCADA system, would hardly be practical in less than a few volumes. The pretensions of this research are both modest and of a more immediate value to the reader.