Author: Russell Johnson
Publisher: American Mathematical Soc.
ISBN: 0821808656
Category : Computers
Languages : en
Pages : 63
Book Description
This volume develops a systematic study of time-dependent control processes. The basic problem of null controllability of linear systems is first considered. Using methods of ergodic theory and topological dynamics, general local null controllability criteria are given. Then the subtle question of global null controllability is studied. Next, the random linear feedback and stabilization problem is posed and solved. Using concepts of exponential dichotomy and rotation number for linear Hamiltonian systems, a solution of the Riccati equation is obtained which has extremely good robustness properties and which also preserves all the smoothness and recurrence properties of the coefficients. Finally, a general version of the local nonlinear feedback stabilization problem is solved.
Controllability, Stabilization, and the Regulator Problem for Random Differential Systems
Author: Russell Johnson
Publisher: American Mathematical Soc.
ISBN: 0821808656
Category : Computers
Languages : en
Pages : 63
Book Description
This volume develops a systematic study of time-dependent control processes. The basic problem of null controllability of linear systems is first considered. Using methods of ergodic theory and topological dynamics, general local null controllability criteria are given. Then the subtle question of global null controllability is studied. Next, the random linear feedback and stabilization problem is posed and solved. Using concepts of exponential dichotomy and rotation number for linear Hamiltonian systems, a solution of the Riccati equation is obtained which has extremely good robustness properties and which also preserves all the smoothness and recurrence properties of the coefficients. Finally, a general version of the local nonlinear feedback stabilization problem is solved.
Publisher: American Mathematical Soc.
ISBN: 0821808656
Category : Computers
Languages : en
Pages : 63
Book Description
This volume develops a systematic study of time-dependent control processes. The basic problem of null controllability of linear systems is first considered. Using methods of ergodic theory and topological dynamics, general local null controllability criteria are given. Then the subtle question of global null controllability is studied. Next, the random linear feedback and stabilization problem is posed and solved. Using concepts of exponential dichotomy and rotation number for linear Hamiltonian systems, a solution of the Riccati equation is obtained which has extremely good robustness properties and which also preserves all the smoothness and recurrence properties of the coefficients. Finally, a general version of the local nonlinear feedback stabilization problem is solved.
Controllability, Stabilization, and the Regulator Problem for Random
Author: Russell Johnson
Publisher: Oxford University Press, USA
ISBN: 9781470402358
Category : Control theory
Languages : en
Pages : 63
Book Description
This volume develops a systematic study of time-dependent control processes. The basic problem of null controllability of linear systems is first considered. Using methods of ergodic theory and topological dynamics, general local null controllability criteria are given. Then the subtle question of global null controllability is studied. Next, the random linear feedback and stabilization problem is posed and solved. Using concepts of exponential dichotomy and rotation number for linear Hamiltonian systems, a solution of the Riccati equation is obtained which has extremely good robustness properties and which also preserves all the smoothness and recurrence properties of the coefficients. Finally, a general version of the local nonlinear feedback stabilization problem is solved.
Publisher: Oxford University Press, USA
ISBN: 9781470402358
Category : Control theory
Languages : en
Pages : 63
Book Description
This volume develops a systematic study of time-dependent control processes. The basic problem of null controllability of linear systems is first considered. Using methods of ergodic theory and topological dynamics, general local null controllability criteria are given. Then the subtle question of global null controllability is studied. Next, the random linear feedback and stabilization problem is posed and solved. Using concepts of exponential dichotomy and rotation number for linear Hamiltonian systems, a solution of the Riccati equation is obtained which has extremely good robustness properties and which also preserves all the smoothness and recurrence properties of the coefficients. Finally, a general version of the local nonlinear feedback stabilization problem is solved.
Algebraic and Strong Splittings of Extensions of Banach Algebras
Author: William G. Bade
Publisher: American Mathematical Soc.
ISBN: 0821810588
Category : Mathematics
Languages : en
Pages : 129
Book Description
In this volume, the authors address the following: Let $A$ be a Banach algebra, and let $\sum\:\ 0\rightarrow I\rightarrow\frak A\overset\pi\to\longrightarrow A\rightarrow 0$ be an extension of $A$, where $\frak A$ is a Banach algebra and $I$ is a closed ideal in $\frak A$. The extension splits algebraically (respectively, splits strongly) if there is a homomorphism (respectively, continuous homomorphism) $\theta\: A\rightarrow\frak A$ such that $\pi\circ\theta$ is the identity on $A$. Consider first for which Banach algebras $A$ it is true that every extension of $A$ in a particular class of extensions splits, either algebraically or strongly, and second for which Banach algebras it is true that every extension of $A$ in a particular class which splits algebraically also splits strongly. These questions are closely related to the question when the algebra $\frak A$ has a (strong) Wedderburn decomposition. The main technique for resolving these questions involves the Banach cohomology group $\cal H2(A,E)$ for a Banach $A$-bimodule $E$, and related cohomology groups. Later chapters are particularly concerned with the case where the ideal $I$ is finite-dimensional. Results are obtained for many of the standard Banach algebras $A$.
Publisher: American Mathematical Soc.
ISBN: 0821810588
Category : Mathematics
Languages : en
Pages : 129
Book Description
In this volume, the authors address the following: Let $A$ be a Banach algebra, and let $\sum\:\ 0\rightarrow I\rightarrow\frak A\overset\pi\to\longrightarrow A\rightarrow 0$ be an extension of $A$, where $\frak A$ is a Banach algebra and $I$ is a closed ideal in $\frak A$. The extension splits algebraically (respectively, splits strongly) if there is a homomorphism (respectively, continuous homomorphism) $\theta\: A\rightarrow\frak A$ such that $\pi\circ\theta$ is the identity on $A$. Consider first for which Banach algebras $A$ it is true that every extension of $A$ in a particular class of extensions splits, either algebraically or strongly, and second for which Banach algebras it is true that every extension of $A$ in a particular class which splits algebraically also splits strongly. These questions are closely related to the question when the algebra $\frak A$ has a (strong) Wedderburn decomposition. The main technique for resolving these questions involves the Banach cohomology group $\cal H2(A,E)$ for a Banach $A$-bimodule $E$, and related cohomology groups. Later chapters are particularly concerned with the case where the ideal $I$ is finite-dimensional. Results are obtained for many of the standard Banach algebras $A$.
Cutting Brownian Paths
Author: Richard F. Bass
Publisher: American Mathematical Soc.
ISBN: 0821809687
Category : Mathematics
Languages : en
Pages : 113
Book Description
A long open problem in probability theory has been the following: Can the graph of planar Brownian motion be split by a straight line? In this volume, the authors provide a solution, discuss related works, and present a number of open problems.
Publisher: American Mathematical Soc.
ISBN: 0821809687
Category : Mathematics
Languages : en
Pages : 113
Book Description
A long open problem in probability theory has been the following: Can the graph of planar Brownian motion be split by a straight line? In this volume, the authors provide a solution, discuss related works, and present a number of open problems.
Splitting Theorems for Certain Equivariant Spectra
Author: L. Gaunce Lewis
Publisher: American Mathematical Soc.
ISBN: 082182046X
Category : Mathematics
Languages : en
Pages : 106
Book Description
This book is intended for graduate students and research mathematicians interested in algebraic topology.
Publisher: American Mathematical Soc.
ISBN: 082182046X
Category : Mathematics
Languages : en
Pages : 106
Book Description
This book is intended for graduate students and research mathematicians interested in algebraic topology.
Study of the Critical Points at Infinity Arising from the Failure of the Palais-Smale Condition for n-Body Type Problems
Author: Hasna Riahi
Publisher: American Mathematical Soc.
ISBN: 0821808737
Category : Mathematics
Languages : en
Pages : 127
Book Description
In this work, the author examines the following: When the Hamiltonian system $m i \ddot{q} i + (\partial V/\partial q i) (t,q) =0$ with periodicity condition $q(t+T) = q(t),\; \forall t \in \germ R$ (where $q {i} \in \germ R{\ell}$, $\ell \ge 3$, $1 \le i \le n$, $q = (q {1},...,q {n})$ and $V = \sum V {ij}(t,q {i}-q {j})$ with $V {ij}(t,\xi)$ $T$-periodic in $t$ and singular in $\xi$ at $\xi = 0$) is posed as a variational problem, the corresponding functional does not satisfy the Palais-Smale condition and this leads to the notion of critical points at infinity. This volume is a study of these critical points at infinity and of the topology of their stable and unstable manifolds. The potential considered here satisfies the strong force hypothesis which eliminates collision orbits. The details are given for 4-body type problems then generalized to n-body type problems.
Publisher: American Mathematical Soc.
ISBN: 0821808737
Category : Mathematics
Languages : en
Pages : 127
Book Description
In this work, the author examines the following: When the Hamiltonian system $m i \ddot{q} i + (\partial V/\partial q i) (t,q) =0$ with periodicity condition $q(t+T) = q(t),\; \forall t \in \germ R$ (where $q {i} \in \germ R{\ell}$, $\ell \ge 3$, $1 \le i \le n$, $q = (q {1},...,q {n})$ and $V = \sum V {ij}(t,q {i}-q {j})$ with $V {ij}(t,\xi)$ $T$-periodic in $t$ and singular in $\xi$ at $\xi = 0$) is posed as a variational problem, the corresponding functional does not satisfy the Palais-Smale condition and this leads to the notion of critical points at infinity. This volume is a study of these critical points at infinity and of the topology of their stable and unstable manifolds. The potential considered here satisfies the strong force hypothesis which eliminates collision orbits. The details are given for 4-body type problems then generalized to n-body type problems.
Simplicial Dynamical Systems
Author: Ethan Akin
Publisher: American Mathematical Soc.
ISBN: 0821813838
Category : Mathematics
Languages : en
Pages : 215
Book Description
A simplicial dynamical system is a simplicial map $g: K DEGREES* \rightarrow K$ where $K$ is a finite simplicial complex triangulating a compact polyhedron $X$ and $K DEGREES*$ is a proper subdivision of $K$, for example, the barycentric or any further subdivision. the dynamics of the asociated piecewise linear map $g: X X$ can be analyzed by using certain naturally related subshifts of finite type. Any continous map on $X$ can be $C DEGREES0$ approximated by such systems. Other examples yield interesting
Publisher: American Mathematical Soc.
ISBN: 0821813838
Category : Mathematics
Languages : en
Pages : 215
Book Description
A simplicial dynamical system is a simplicial map $g: K DEGREES* \rightarrow K$ where $K$ is a finite simplicial complex triangulating a compact polyhedron $X$ and $K DEGREES*$ is a proper subdivision of $K$, for example, the barycentric or any further subdivision. the dynamics of the asociated piecewise linear map $g: X X$ can be analyzed by using certain naturally related subshifts of finite type. Any continous map on $X$ can be $C DEGREES0$ approximated by such systems. Other examples yield interesting
Caustics for Dissipative Semilinear Oscillations
Author: Jean-Luc Joly
Publisher: American Mathematical Soc.
ISBN: 0821820419
Category : Mathematics
Languages : en
Pages : 87
Book Description
This book is intended for graduate students and research mathematicians interested in partial differential equations.
Publisher: American Mathematical Soc.
ISBN: 0821820419
Category : Mathematics
Languages : en
Pages : 87
Book Description
This book is intended for graduate students and research mathematicians interested in partial differential equations.
Iterated Function Systems and Permutation Representations of the Cuntz Algebra
Author: Ola Bratteli
Publisher: American Mathematical Soc.
ISBN: 0821809628
Category : C*-algebras
Languages : en
Pages : 106
Book Description
This book is intended for graduate students and research mathematicians working in functional analysis.
Publisher: American Mathematical Soc.
ISBN: 0821809628
Category : C*-algebras
Languages : en
Pages : 106
Book Description
This book is intended for graduate students and research mathematicians working in functional analysis.
Estimating the Error of Numerical Solutions of Systems of Reaction-Diffusion Equations
Author: Donald J. Estep
Publisher: American Mathematical Soc.
ISBN: 0821820729
Category : Mathematics
Languages : en
Pages : 125
Book Description
This paper is concerned with the computational estimation of the error of numerical solutions of potentially degenerate reaction-diffusion equations. The underlying motivation is a desire to compute accurate estimates as opposed to deriving inaccurate analytic upper bounds. In this paper, we outline, analyze, and test an approach to obtain computational error estimates based on the introduction of the residual error of the numerical solution and in which the effects of the accumulation of errors are estimated computationally. We begin by deriving an a posteriori relationship between the error of a numerical solution and its residual error using a variational argument. This leads to the introduction of stability factors, which measure the sensitivity of solutions to various kinds of perturbations. Next, we perform some general analysis on the residual errors and stability factors to determine when they are defined and to bound their size. Then we describe the practical use of the theory to estimate the errors of numerical solutions computationally. Several key issues arise in the implementation that remain unresolved and we present partial results and numerical experiments about these points. We use this approach to estimate the error of numerical solutions of nine standard reaction-diffusion models and make a systematic comparison of the time scale over which accurate numerical solutions can be computed for these problems. We also perform a numerical test of the accuracy and reliability of the computational error estimate using the bistable equation. Finally, we apply the general theory to the class of problems that admit invariant regions for the solutions, which includes seven of the main examples. Under this additional stability assumption, we obtain a convergence result in the form of an upper bound on the error from the a posteriori error estimate. We conclude by discussing the preservation of invariant regions under discretization.
Publisher: American Mathematical Soc.
ISBN: 0821820729
Category : Mathematics
Languages : en
Pages : 125
Book Description
This paper is concerned with the computational estimation of the error of numerical solutions of potentially degenerate reaction-diffusion equations. The underlying motivation is a desire to compute accurate estimates as opposed to deriving inaccurate analytic upper bounds. In this paper, we outline, analyze, and test an approach to obtain computational error estimates based on the introduction of the residual error of the numerical solution and in which the effects of the accumulation of errors are estimated computationally. We begin by deriving an a posteriori relationship between the error of a numerical solution and its residual error using a variational argument. This leads to the introduction of stability factors, which measure the sensitivity of solutions to various kinds of perturbations. Next, we perform some general analysis on the residual errors and stability factors to determine when they are defined and to bound their size. Then we describe the practical use of the theory to estimate the errors of numerical solutions computationally. Several key issues arise in the implementation that remain unresolved and we present partial results and numerical experiments about these points. We use this approach to estimate the error of numerical solutions of nine standard reaction-diffusion models and make a systematic comparison of the time scale over which accurate numerical solutions can be computed for these problems. We also perform a numerical test of the accuracy and reliability of the computational error estimate using the bistable equation. Finally, we apply the general theory to the class of problems that admit invariant regions for the solutions, which includes seven of the main examples. Under this additional stability assumption, we obtain a convergence result in the form of an upper bound on the error from the a posteriori error estimate. We conclude by discussing the preservation of invariant regions under discretization.