Global ETD Search

41	Online trajectory planning and observer based control Anisi, David A. January 2006 (has links) <p>The main body of this thesis consists of four appended papers. The first two consider different aspects of the trajectory planning problem, while the last two deal with observer design for mobile robotic and Euler-Lagrange systems respectively.</p><p>The first paper addresses the problem of designing a real time, high performance trajectory planner for aerial vehicles. The main contribution is two-fold. Firstly, by augmenting a novel safety maneuver at the end of the planned trajectory, this paper extends previous results by having provable safety properties in a 3D setting. Secondly, assuming initial feasibility, the planning method is shown to have finite time task completion. Moreover, in the second part of the paper, the problem of simultaneous arrival of multiple aerial vehicles is considered. By using a time-scale separation principle, one is able to adopt standard Laplacian control to this consensus problem, which is neither unconstrained, nor first order.</p><p>Direct methods for trajectory optimization are traditionally based on<i> a</i> <i>priori </i>temporal discretization and collocation methods. In the second paper, the problem of adaptive node distribution is formulated as a constrained optimization problem, which is to be included in the underlying nonlinear mathematical programming problem. The benefits of utilizing the suggested method for online trajectory optimization are illustrated by a missile guidance example.</p><p>In the third paper, the problem of active observer design for an important class of non-uniformly observable systems, namely mobile robotics systems, is considered. The set of feasible configurations and the set of output flow equivalent states are defined. It is shown that the inter-relation between these two sets may serve as the basis for design of active observers. The proposed observer design methodology is illustrated by considering a unicycle robot model, equipped with a set of range-measuring sensors.</p><p>Finally, in the fourth paper, a geometrically intrinsic observer for Euler-Lagrange systems is defined and analyzed. This observer is a generalization of the observer recently proposed by Aghannan and Rouchon. Their contractivity result is reproduced and complemented by a proof that the region of contraction is infinitely thin. However, assuming <i>a</i> <i>priori </i>bounds on the velocities, convergence of the observer is shown by means of Lyapunov's direct method in the case of configuration manifolds with constant curvature.</p> Computational Optimal Control Receding Horizon Control Mission Uncertainty Safety Task Completion Consensus Problem Simultaneous Arrival Adaptive Grid Methods Missile Guidance Nonlinear Observer Design Active Observers Non--uniformly Observable Systems Mobile Robotic Systems Intrinsic Observers Differential Geometric Methods Euler-Lagrange Systems Contraction Analysis. Optimization, systems theory Optimeringslära, systemteori
42	Hopf Bifurcation from Infinity in Asymptotically Linear Autonomous Systems with Delay Biglands, Adrian Unknown Date No description available.
43	Studies of the Boundary Behaviour of Functions Related to Partial Differential Equations and Several Complex Variables Persson, Håkan January 2015 (has links) This thesis consists of a comprehensive summary and six scientific papers dealing with the boundary behaviour of functions related to parabolic partial differential equations and several complex variables. Paper I concerns solutions to non-linear parabolic equations of linear growth. The main results include a backward Harnack inequality, and the Hölder continuity up to the boundary of quotients of non-negative solutions vanishing on the lateral boundary of an NTA cylinder. It is also shown that the Riesz measure associated with such solutions has the doubling property. Paper II is concerned with solutions to linear degenerate parabolic equations, where the degeneracy is controlled by a weight in the Muckenhoupt class 1+2/n. Two main results are that non-negative solutions which vanish continuously on the lateral boundary of an NTA cylinder satisfy a backward Harnack inequality and that the quotient of two such functions is Hölder continuous up to the boundary. Another result is that the parabolic measure associated to such equations has the doubling property. In Paper III, it is shown that a bounded pseudoconvex domain whose boundary is α-Hölder for each 0<α<1, is hyperconvex. Global estimates of the exhaustion function are given. In Paper IV, it is shown that on the closure of a domain whose boundary locally is the graph of a continuous function, all plurisubharmonic functions with continuous boundary values can be uniformly approximated by smooth plurisubharmonic functions defined in neighbourhoods of the closure of the domain. Paper V studies Poletsky’s notion of plurisubharmonicity on compact sets. It is shown that a function is plurisubharmonic on a given compact set if, and only if, it can be pointwise approximated by a decreasing sequence of smooth plurisubharmonic functions defined in neighbourhoods of the set. Paper VI introduces the notion of a P-hyperconvex domain. It is shown that in such a domain, both the Dirichlet problem with respect to functions plurisubharmonic on the closure of the domain, and the problem of approximation by smooth plurisubharmoinc functions in neighbourhoods of the closure of the domain have satisfactory answers in terms of plurisubharmonicity on the boundary. uniformly parabolic equations non-linear parabolic equations linear growth Lipschitz domain NTA-domain Riesz measure boundary behavior boundary Harnack degenerate parabolic parabolic measure plurisubharmonic functions continuous boundary hyperconvexity bounded exhaustion function Hölder for all exponents log-lipschitz boundary regularity approximation Mergelyan type approximation plurisubharmonic functions on compacts Jensen measures monotone convergence plurisubharmonic extension plurisubharmonic boundary values
44	On some results of analysis in metric spaces and fuzzy metric spaces Aphane, Maggie 12 1900 (has links) The notion of a fuzzy metric space due to George and Veeramani has many advantages in analysis since many notions and results from classical metric space theory can be extended and generalized to the setting of fuzzy metric spaces, for instance: the notion of completeness, completion of spaces as well as extension of maps. The layout of the dissertation is as follows: Chapter 1 provide the necessary background in the context of metric spaces, while chapter 2 presents some concepts and results from classical metric spaces in the setting of fuzzy metric spaces. In chapter 3 we continue with the study of fuzzy metric spaces, among others we show that: the product of two complete fuzzy metric spaces is also a complete fuzzy metric space. Our main contribution is in chapter 4. We introduce the concept of a standard fuzzy pseudo metric space and present some results on fuzzy metric identification. Furthermore, we discuss some properties of t-nonexpansive maps. / Mathematical Sciences / M. Sc. (Mathematics) Metric space Cauchy sequence Compactness Precompactness Completeness Continuity Uniform continuity Isometry Uniform convergence Seperable Nested Closed sets Diameter Pseudo metric space Fuzzy metric space Standard fuzzy metric space Fuzzy pseudo metric space Metric identification Fuzzy metric identification Nonexpansive map t-nonexpansive map t-uniformly continuous map t-isometry map Quotient map Quotient topology Quotient space Natural map Topological space 514.325 Metric spaces Fuzzy topology
45	Online trajectory planning and observer based control Anisi, David A. January 2006 (has links) The main body of this thesis consists of four appended papers. The first two consider different aspects of the trajectory planning problem, while the last two deal with observer design for mobile robotic and Euler-Lagrange systems respectively. The first paper addresses the problem of designing a real time, high performance trajectory planner for aerial vehicles. The main contribution is two-fold. Firstly, by augmenting a novel safety maneuver at the end of the planned trajectory, this paper extends previous results by having provable safety properties in a 3D setting. Secondly, assuming initial feasibility, the planning method is shown to have finite time task completion. Moreover, in the second part of the paper, the problem of simultaneous arrival of multiple aerial vehicles is considered. By using a time-scale separation principle, one is able to adopt standard Laplacian control to this consensus problem, which is neither unconstrained, nor first order. Direct methods for trajectory optimization are traditionally based on a priori temporal discretization and collocation methods. In the second paper, the problem of adaptive node distribution is formulated as a constrained optimization problem, which is to be included in the underlying nonlinear mathematical programming problem. The benefits of utilizing the suggested method for online trajectory optimization are illustrated by a missile guidance example. In the third paper, the problem of active observer design for an important class of non-uniformly observable systems, namely mobile robotics systems, is considered. The set of feasible configurations and the set of output flow equivalent states are defined. It is shown that the inter-relation between these two sets may serve as the basis for design of active observers. The proposed observer design methodology is illustrated by considering a unicycle robot model, equipped with a set of range-measuring sensors. Finally, in the fourth paper, a geometrically intrinsic observer for Euler-Lagrange systems is defined and analyzed. This observer is a generalization of the observer recently proposed by Aghannan and Rouchon. Their contractivity result is reproduced and complemented by a proof that the region of contraction is infinitely thin. However, assuming a priori bounds on the velocities, convergence of the observer is shown by means of Lyapunov's direct method in the case of configuration manifolds with constant curvature. / QC 20101108 Computational Optimal Control Receding Horizon Control Mission Uncertainty Safety Task Completion Consensus Problem Simultaneous Arrival Adaptive Grid Methods Missile Guidance Nonlinear Observer Design Active Observers Non--uniformly Observable Systems Mobile Robotic Systems Intrinsic Observers Differential Geometric Methods Euler-Lagrange Systems Contraction Analysis. Computational Mathematics Beräkningsmatematik
46	Statistical Inference Chou, Pei-Hsin 26 June 2008 (has links) In this paper, we will investigate the important properties of three major parts of statistical inference: point estimation, interval estimation and hypothesis testing. For point estimation, we consider the two methods of finding estimators: moment estimators and maximum likelihood estimators, and three methods of evaluating estimators: mean squared error, best unbiased estimators and sufficiency and unbiasedness. For interval estimation, we consider the the general confidence interval, confidence interval in one sample, confidence interval in two samples, sample sizes and finite population correction factors. In hypothesis testing, we consider the theory of testing of hypotheses, testing in one sample, testing in two samples, and the three methods of finding tests: uniformly most powerful test, likelihood ratio test and goodness of fit test. Many examples are used to illustrate their applications. finite population correction factor statistical hypothesis type I error composite hypothesis power Central limit theorem Basu theorem critical value goodness of fit test likelihood ratio test Lehmann-Scheffe theorem complete statistic ancillary statistic P-value type II error Rao-Blackwell theorem simple hypothesis one-sided test two-sided test significance level sufficient statistic alternative hypothesis testing hypothesis null hypothesis rejection region confidence interval confidence level minimum variance unbiased estimator interval estimation uniformly most powerful test Cramer-Rao inequality likelihood function mean square error moment estimator error of estimation point estimation maximum likelihood estimator bias consistent estimator minimal sufficient statistic factorization theorem unbiased estimator statistic most powerful test test statistics Neyman-Pearson lemma decision rule
47	Théorie non linéaire du potentiel et équations quasilinéaires avec données mesures / Nonlinear potential theory and quasilinear equations with measure data Nguyen, Quoc-Hung 25 September 2014 (has links) Cette thèse concerne l’existence et la régularité de solutions d’équations non-linéaires elliptiques, d’équations paraboliques et d’équations de Hesse avec mesures, et les critères de l’existence de solutions grandes d’équations elliptiques et paraboliques non-linéaires. / This thesis is concerned to the existence and regularity of solutions to nonlinear elliptic, parabolic and Hessian equations with measure, and criteria for the existence of large solutions to some nonlinear elliptic and parabolic equations. Équations quasi-linéaire elliptiques Équations quasi-linéaires paraboliques Solutions renormalisée Solutions maximales Solutions grandes Potentiel de Wolff Potentiel de Riesz Potentiel de Bessel Potentiel maximal Noyau de la chaleur Noyau de Bessel parabolique Mesures de Radon Capacités de Lorentz-Bessel Capacités de Bessel Capacités de Hausdorff Lemme de recouvrement de Vitali Espaces de Lorentz Domaines épais uniformes Domaines plats de Reifenberg Estimations de décroissance Estimations de Lorentz-Morrey Estimations capacitaires Équations de milieu poreux Équations de type Riccati Quasilinear elliptic equations Quasilinear parabolic equations Renormalized solutions Maximal solutions Large solutions Wolff potential Riesz potential Bessel Potential Maximal potential Heat kernel Parabolic Bessel kernel Radon measures Lorentz-Bessel capacities Bessel capacities Hausdorff capacities Vitial covering Lemma Lorentz spaces Uniformly thick domain Reifenberg flat domain Decay estimates Lorentz- Morrey estimates Capacitary estimates Porous medium equations Riccati type Equations

Page generated in 0.0508 seconds