Convex Optimization. Mikhail Moklyachuk
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Название: Convex Optimization

Автор: Mikhail Moklyachuk

Издательство: John Wiley & Sons Limited

Жанр: Математика

Серия:

isbn: 9781119804086

isbn:

СКАЧАТЬ Closed convex hull of set X dim X Dimension of set X ∂ X Boundary of set X K * Dual cone associated with cone K
A ray proceeding from a point
in the direction h Hpβ A hyperplane with the normal vector p
Half-spaces generated by hyperplane Hpβ πX(a) Projection of point a onto set X ρ(X1, X2) Distance between sets X1 and X2 epi f Epigraph of function f Sr (f) Sublevel set of function f dom f Effective set of function f f1f2 Infimal convolution of functions f1, f2 μ(x\X) Minkowski function γX(x) Gauge function δ(x\X) Indicator function σ(x\X) Support function f * Conjugate function ∂f(x) Subdifferential of function f at point x
Superdifferential of function f at point x ∏(ℝm) Set of all non-empty subsets of the space ℝm

      Introduction

      Convex analysis and optimization have an increasing impact on many areas of mathematics and applications including control systems, estimation and signal processing, communications and networks, electronic circuit design, data analysis and modeling, statistics, and economics and finance. There are several fundamental books devoted to different aspects of convex analysis and optimization. Among them we can mention Optima and Equilibria: An Introduction to Nonlinear Analysis by Aubin (1998), Convex Analysis by Rockafellar (1970), Convex Analysis and Minimization Algorithms (in two volumes) by Hiriart-Urruty and Lemaréchal (1993) and its abridged version (2002), Convex Analysis and Nonlinear Optimization by Borwein and Lewis (2000), Convex Optimization by Boyd and Vandenberghe (2004), Convex Analysis and Optimization by Bertsekas et al. (2003), Convex Analysis and Extremal Problems by Pshenichnyj (1980), A Course in Optimization Methods by Sukharev et al. (2005), Convex Analysis: An Introductory Text by Van Tiel (1984), as well as other books listed in the bibliography (see Alekseev et al. (1984, 1987); Alekseev and Timokhov (1991); Clarke (1983); Hiriart-Urruty (1998); Ioffe and Tikhomirov (1979) and Nesterov (2004)).

      This book provides easy access to the basic principles and methods for solving constrained and unconstrained convex optimization problems. Structurally, the book has been divided into the following parts: basic methods for solving constrained and unconstrained optimization problems with differentiable objective functions, convex sets and their properties, convex functions, their properties and generalizations, subgradients and subdifferentials, and basic principles and methods for solving constrained and unconstrained convex optimization problems. The first part of the book describes methods for finding the extremum of functions of one and many variables. Problems of constrained and unconstrained optimization (problems with restrictions of inequality and inequality types) are investigated. The necessary and sufficient conditions of the extremum, the Lagrange method, are described.

      We give detailed proofs for most of the results presented in the book and also include many figures and exercises for better understanding of the material. Finally, we present solutions and hints to selected exercises at the end of the book. Exercises are given at the end of each chapter while figures and examples are provided throughout the whole text. The list of references contains texts which are closely related to the topics considered in the book and may be helpful to the reader for advanced studies of convex analysis, its applications and further extensions. Since only elementary knowledge in linear algebra and basic calculus is required, this book can be used as a textbook for both undergraduate and graduate level courses in convex optimization and its applications. In fact, the author has used these lecture notes for teaching such classes at Kyiv National University. We hope that the book will make convex optimization methods more accessible to large groups of undergraduate and graduate students, researchers in different disciplines and practitioners. The idea was to prepare materials of lectures in accordance with the suggestion made by Einstein: “Everything should be made as simple as possible, but not simpler.”

      1

      Optimization Problems with Differentiable Objective Functions

      1.1. Basic concepts

      The word “maximum” means the largest, and the word “minimum” means the smallest. These two concepts are combined with the term “extremum”, which means the extreme. Also pertinent is the term “optimal” (from Latin optimus), which means the best. The problems of determining the largest and smallest quantities are called extremum problems. Such problems arise in different areas of activity and therefore different terms are used for the descriptions of the problems. To use the theory of extremum problems, it is necessary to describe problems in the language of mathematics. This process СКАЧАТЬ