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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Nonlinear state-space control design for displacement-based real-time testing of structural systems

Moosavi Nanehkaran, Seyed Abdol Hadi Unknown Date
No description available.
172

Simplifying an Infinitely Complex State-Space: Real-Time Strategy Optimization in Supreme Commander: Forged Alliance

Cornell, Michael 01 January 2015 (has links)
Supreme Commander: Forged Alliance is considered to be among the most complex real-time strategy games that exist today. I am testing whether or not players can gain meaningful strategic value through statistical analysis. In particular, I have focused my analysis on how players can redefine their path from their initial-state to their goal-state in one versus one games, how players can optimize their chance of winning through faction selection, and how players ought to evaluate balance in team games. Through regression analysis, I have concluded that there is potential for statistics to inform player behavior when it comes to each of these strategies.
173

Nonlinear state-space control design for displacement-based real-time testing of structural systems

Moosavi Nanehkaran, Seyed Abdol Hadi 06 1900 (has links)
This study presents the nonlinear design of a state space controller to control hydraulic actuators under displacement control, specifically for real-time pseudo-dynamic testing applications. The proposed control design process uses the nonlinear state space model of the dynamics of the system to be controlled; and utilizes state feedback linearization through a transformation of the state variables. Comparisons of numerical simulation results for linear state-space and nonlinear state-space controllers are given. Also robustness of the control design with respect to identified parameters is investigated. It is shown that a controller with improved performance can be designed using nonlinear state space control design techniques, provided that a representative model of the system is available. / Structural Engineering
174

Charting the State Space of Plane Couette Flow: Equilibria, Relative Equilibria, and Heteroclinic Connections

Halcrow, Jonathan 08 July 2008 (has links)
The study of turbulence has been dominated historically by a bottom-up approach, with a much stronger emphasis on the physical structure of flows than on that of the dynam- ical state space. Turbulence has traditionally been described in terms of various visually recognizable physical features, such as waves and vortices. Thanks to recent theoretical as well as experimental advancements, it is now possible to take a more top-down approach to turbulence. Recent work has uncovered non-trivial equilibria as well as relative periodic orbits in several turbulent systems. Furthermore, it is now possible to verify theoretical results at a high degree of precision, thanks to an experimental technique known as Particle Image Velocimetry. These results squarely frame moderate Reynolds number Re turbulence in boundary shear flows as a tractable dynamical systems problem. In this thesis, I intend to elucidate the finer structure of the state space of moderate Re wall-bounded turbulent flows in hope of providing a more accurate and precise description of this complex phenomenon. Computation of new undiscovered equilibria, relative equilibria, and their heteroclinic connections provide a skeleton upon which a numerically accurate description of turbulence can be framed. The behavior of the equilibria under variation of Reynolds number and cell aspect ratios is also examined. It is hoped that this description of the state space will provide new avenues for research into nonlinear control systems for shear flows as well as quantitative predictions of transport properties of moderate Re fluid flows.
175

Enabling scalable self-management for enterprise-scale systems

Kumar, Vibhore 07 May 2008 (has links)
Implementing self-management for enterprise systems is difficult. First, the scale and complexity of such systems makes it hard to understand and interpret system behavior or worse, the root causes of certain behaviors. Second, it is not clear how the goals specified at a system-level translate to component-level actions that drive the system. Third, the dynamic environments in which such systems operate requires self-management techniques that not only adapt the system but also adapt their own decision making processes. Finally, to build a self-management solution that is acceptable to administrators, it should have the properties of tractability and trust, which allow an administrator to both understand and fine-tune self-management actions. This dissertation work introduces, implements, and evaluates iManage, a novel system state-space based framework for enabling self-management of enterprise-scale systems. The system state-space, in iManage, is defined to be a collection of monitored system parameters and metrics (termed system variables). In addition, from amongst the system variables, it identifies the variables of interest, which determine the operational status of a system, and the controllable variables, which are the ones that can be deterministically modified to affect the operational status of a system. Using this formal representation, we have developed and integrated into iManage techniques that establish a probabilistic model relating the variables of interest and the controllable variables under the prevailing operational conditions. Such models are then used by iManage to determine corrective actions in case of SLA violations and/or to determine per-component ranges for controllable variables, which if independently adhered to by each component, lead to SLA compliance. To address the issue of scale in determining system models, iManage makes use of a novel state-space partitioning scheme that partitions the state-space into smaller sub-spaces thereby allowing us to more precisely model the critical system aspects. Our chosen modeling techniques are such that the generated models can be easily understood and modified by the administrator. Furthermore, iManage associates each proposed self-management action with a confidence-attribute that determines whether the action in question merits autonomic enforcement or not.
176

Bayesian inference on dynamics of individual and population hepatotoxicity via state space models

Li, Qianqiu, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xiv, 155 p.; also includes graphics (some col.). Includes bibliographical references (p. 147-155). Available online via OhioLINK's ETD Center
177

Hipersuperfícies tipo-espaço com curvatura de ordem superior constante no Espaço de Sitter. / Space-type hypersurfaces with higher order curvature in the Sitter Space.

SANTOS, Fábio Reis dos. 07 August 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-07T21:04:25Z No. of bitstreams: 1 FÁBIO REIS DOS SANTOS - DISSERTAÇÃO PPGMAT 2013..pdf: 716996 bytes, checksum: 97f7fb742c257421cce66bdb68b5d76e (MD5) / Made available in DSpace on 2018-08-07T21:04:25Z (GMT). No. of bitstreams: 1 FÁBIO REIS DOS SANTOS - DISSERTAÇÃO PPGMAT 2013..pdf: 716996 bytes, checksum: 97f7fb742c257421cce66bdb68b5d76e (MD5) Previous issue date: 2013-03 / Capes / Neste trabalho, desenvolvemos as Fórmulas Integrais tipo-Minkowski para hipersuperfícies tipo-espaço, compactas com bordo imersas no espaço de Sitter S n+1 1 e possuindo alguma curvatura de ordem superior constante. Aplicamos estas, para estabelecer uma relação entre a curvatura média e a geometria do bordo quando se trata de uma esfera geodésica contida em um hiperplano do Steady State space Hn+1 ⊂ S n+1. / In this work we develop Minkowski-type formulae for compact spacelike immersed hypersurfaces with boundary and having some constant higher order mean curvature in de Sitter space S n+11. We apply them to establish a relation between the mean curvature and the geometry of the boundary, when it is a geodesic sphere contained into a horizontal hyperplane of the Steady State space Hn+1 ⊂ S n+1 1. .
178

Modelo matemático para controle de um sistema ativo de suspensão automotiva

Azevedo, Claudio Marcio Medeiros de 16 August 2013 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-17T23:03:01Z No. of bitstreams: 1 ClaudioMMA_DISSERT.pdf: 1868632 bytes, checksum: 181427139e69d7b9f1645804fede5b2c (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:07:00Z (GMT) No. of bitstreams: 1 ClaudioMMA_DISSERT.pdf: 1868632 bytes, checksum: 181427139e69d7b9f1645804fede5b2c (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-18T15:07:15Z (GMT) No. of bitstreams: 1 ClaudioMMA_DISSERT.pdf: 1868632 bytes, checksum: 181427139e69d7b9f1645804fede5b2c (MD5) / Made available in DSpace on 2017-07-18T15:07:33Z (GMT). No. of bitstreams: 1 ClaudioMMA_DISSERT.pdf: 1868632 bytes, checksum: 181427139e69d7b9f1645804fede5b2c (MD5) Previous issue date: 2013-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the aid of the mathematical the man uses representations that are able to explain and interpret phenomena in studies, with this, the use of mathematics with language symbolic leads representation of the problem situation in mathematical terms, which in turn, this model can be understood as a set of symbols and relationships that represent a situation, phenomenon, or a real object to be studied. Therefore, this paper presents a mathematical modeling of quarter suspension system of an automobile in order to obtain a transfer function and then put the system in a state space representation. The second part deals with the problems of stabilization in continuous-time linear systems using static output feedback. The second part deals with the problems of stabilization in continuous-time linear systems using static output feedback. The results presented have as their starting point the concept of subspaces (C,A,B)-invariant algebraically characterized by a pair of coupled Sylvester equations, whose solution can be obtained for systems that verify the condition Kimura, in two stages using the algorithm and Lewis Syrmos. In the case of normal systems as studied in this work will be used the technique of the stabilization for two systems satisfying the condition Kimura, will be simulations of this car passing by two external disturbances, and controller gains employees will be obtained by the methods of allocation poles and coupled Sylvester equations, and finishes the work by making a bond regarding the responses of two arrays of feedback gains / Com o auxilio da matemática o homem utiliza representações que são capazes de explicar e interpretar fenômenos em estudos, com isso, o uso da matemática como linguagem simbólica conduz a uma representação da situação problema em termos matemáticos, que por sua vez, este modelo pode ser entendido como um conjunto de símbolos e relações que representa uma situação, um fenômeno, ou um objeto real a ser estudado. Diante disso, o presente trabalho apresenta a modelagem matemática de um quarto do sistema de suspensão de um automóvel, a fim de obter uma função de transferência para em seguida colocar o sistema em uma representação no espaço de estados. Serão tratados também os problemas de estabilização em sistemas lineares contínuos no tempo usando realimentação estática de saídas. Os resultados apresentados têm como ponto de partida o conceito de subespaços (C, A,B)-invariantes caracterizados algebricamente através de um par de equações acopladas de Sylvester, cuja solução pode ser obtida, para sistemas que verificam a condição de Kimura, em duas etapas utilizando o algoritmo de Syrmos e Lewis. No caso de sistemas normais como é estudado neste trabalho será usado à técnica de estabilização para dois sistemas satisfazendo a condição de Kimura será feitas simulações deste automóvel passando por duas perturbações externas, e os ganhos dos controladores empregados serão obtidos através dos métodos de alocação de polos e das equações acopladas de Sylvester, e finaliza o trabalho fazendo um elo em relação a respostas das duas matrizes de ganhos de realimentação / 2017-07-17
179

Non-asymptotic method estimation and applications for fractional order systems / Estimation de méthode non-asymptotique et applications pour les systèmes d'ordre fractionnaire

Wei, Xing 23 November 2017 (has links)
Cette thèse vise à concevoir des estimateurs non-asymptotiques et robustes pour les systèmes linéaires d’ordre fractionnaire dans un environnement bruité. Elle traite une classe des systèmes linéaires d’ordre fractionnaire modélisée par la dite pseudo représentation d’état avec des conditions initiales inconnues. Elle suppose également que les systèmes étudiés ici peuvent être transformés sous la forme canonique de Brunovsky. Pour estimer le pseudo-état, la forme précédente est transformée en une équation différentielle linéaire d’ordre fractionnaire en prenant en compte les valeurs initiales des dérivées fractionnaires séquentielles de la sortie. Ensuite, en utilisant la méthode des fonctions modulatrices, les valeurs initiales précédentes et les dérivées fractionnaires avec des ordres commensurables de la sortie sont données par des formules algébriques avec des intégrales à l’aide d’une méthode récursive. Ainsi, ces formules sont utilisés pour calculer le pseudo-état dans le cas continu sans bruit. En outre, elle fournit un algorithme pour construire les fonctions modulatrices requises à l’accomplissement de l’estimation. Deuxièmement, inspiré par la méthode des fonctions modulatrices développée pour l’estimation de pseudo-état, cette méthode algébrique basée sur un opérateur est introduite pour estimer la dérivée fractionnée avec un ordre arbitraire fractionnaire de la sortie pour les systèmes considérés. Cet opérateur sert à annuler les valeurs initiales non désirées, puis permet d’estimer la dérivée fractionnaire souhaitée par une nouvelle formule algébrique à l’aide d’une méthode récursive. Troisièmement, l’estimateur du pseudo-état et le différenciateur d’ordre fractionnaire obtenus précédemment sont étudiés respectivement dans le cas discret et bruité. Chacun d’entre eux contient une erreur numérique due à la méthode d’intégration numérique utilisée et au bruit. En particulier, elle fournit une analyse pour diminuer la contribution du bruit au moyen d’une d’erreur bornée qui permet de sélectionner les degrés optimaux des fonctions de modulation à chaque instant. Ensuite, des exemples numériques sont donnés pour mettre en évidence la précision, la robustesse et la propriété non-asymptotique des estimateurs proposés. En outre, les comparaisons avec certaines méthodes existantes et avec un nouvel observateur d’ordre fractionnaire de typeH1sont montrées. Enfin, elle donne des conclusions / This thesis aims to design non-asymptotic and robust estimators for a class of fractional order linear systems in noisy environment. It deals with a class of commensurate fractional order linear systems modeled by the so-called pseudo-state space representation with unknown initial conditions. It also assumed that linear systems under study can be transformed into the Brunovsky’s observable canonical form. Firstly, the pseudo-state of the considered systems is estimated. For this purpose, the Brunovsky’s observable canonical form is transformed into a fractional order linear differential equation involving the initial values of the fractional sequential derivatives of the output. Then, using the modulating functions method, the former initial values and the fractional derivatives with commensurate orders of the output are given by algebraic integral formulae in a recursive way. Thereby, they are used to calculate the pseudo-state in the continuous noise-free case. Moreover, to perform this estimation, it provides an algorithm to build the required modulating functions. Secondly, inspired by the modulating functions method developed for pseudo-state estimation, an operator based algebraic method is introduced to estimate the fractional derivative with an arbitrary fractional order of the output. This operator is applied to cancel the former initial values and then enables to estimate the desired fractional derivative by a new algebraic formula using a recursive way. Thirdly, the pseudo-state estimator and the fractional order differentiator are studied in discrete noisy case. Each of them contains a numerical error due to the used numerical integration method, and the noise error contribution due to a class of stochastic processes. In particular, it provides ananalysis to decrease noise contribution by means of an error bound that enables to select the optimal degrees of the modulating functions at each instant. Then, several numerical examples are given to highlight the accuracy, the robustness and the non-asymptotic property of the proposed estimators. Moreover, the comparisons to some existing methods and a new fractional orderH1-like observer are shown. Finally, conclusions are outlined with some perspectives
180

Controle preditivo retroalimentado por estados estimados, aplicado a uma planta laboratorial

Paim, Anderson de Campos January 2009 (has links)
A retroalimentação de controladores preditivos que utilizam modelos em espaço de estado pode ser realizada de duas formas: (a) correção por bias, em que as saídas preditas são corrigidas adicionando-se um valor proporcional a discrepância encontrada entre o valor medido atual e sua respectiva predição e por (b) retroalimentação dos estados, onde se determinam as condições iniciais através da estimação dos estados, e a partir de uma melhor condição inicial se realizam as predições futuras usadas no cálculo das ações de controle. Nesta dissertação estas duas abordagens são comparadas utilizando a Planta Laboratorial de Seis Tanques Esféricos. As técnicas de Filtro de Kalman Estendido (EKF) e Filtro de Kalman Estendido com Restrições (CEKF) foram empregadas para estimar os estados não medidos. Inicialmente foram feitos testes off-line destes algoritmos de estimação. Para estes testes são utilizados uma série de dados da planta laboratorial do estudo de caso, na qual são estudadas as influências de diversos fatores de ajuste que determinam a qualidade final de estimação. Estes ajustes serviram de base para a aplicação destes algoritmos em tempo real, quando então, estimadores de estados estão associados ao sistema de controle do processo baseado em um algoritmo de controle preditivo. Após se ter certificado a qualidade das estimações de estado, partiu-se para sua utilização como uma alternativa de retroalimentação de controladores preditivos. Estes resultados foram comparados com os obtidos através da correção simples por bias. Os resultados experimentais apontam para uma marginal piora devido à retroalimentação por estimadores de estados frente à correção por bias, pelo menos para o caso do controlador preditivo linear utilizado na comparação. Entretanto, espera-se que resultados melhores sejam obtidos no caso de modelos preditivos não-lineares, uma vez que nestes casos o modelo é bem mais sensível à qualidade da condição inicial. / The feedback of controllers that use predictive models in state space can be accomplished in two ways: (a) bias correction, where the predicted outputs are corrected by adding a value proportional to the discrepancy found between the current measurement and its respective prediction; and by (b) state feedback, which establishes the initial conditions through the states estimation, and from a better initial condition are carried out the future predictions used in the calculation of control. In this thesis these two approaches are compared using a Laboratorial Plant of Six Spherical Tanks. The techniques of Extended Kalman Filter (EKF) and Constraint Extended Kalman Filter (CEKF) were used to estimate the unmeasured states. Initially, tests were carried out off-line for theses estimation algorithms. For such testing are used a dataset of the plant in case study, in which are studied the influences of several adjustment factors that they determine the final quality of estimation. These adjustments were used of base for the application of these algorithms in real time, when then state estimators are associated with the system of process control based on a predictive control algorithm. After having ascertained the quality of the state estimates, begins its use as an alternative for feedback of predictive controllers. These results were compared with those obtained by the simple correction of bias. The experimental results show a marginal worsening due to feedback from state estimated compared with bias correction, at least for the case of linear predictive controller used in the comparison. However, one expects that better results will be obtained in the case of non-linear predictive models, since in these cases the model is much more sensitive to the quality of the initial condition.

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