% !TeX root = ../main.tex \begin{survey} \label{cha:survey} \title{Title of the Survey} \maketitle 写出至少 5000 外文印刷字符的调研阅读报告或者书面翻译 1-2 篇(不少于 2 万外文印刷符)。 \tableofcontents \section{Single-Objective Programming} It is impossible to cover in a single chapter every concept of mathematical programming\cite{tex}. This chapter introduces only the basic concepts and techniques of mathematical programming such that readers gain an understanding of them throughout the book.~\cite{abrahams99tex,salomon1995advanced}. The general form of single-objective programming (SOP) is written as follows, \begin{equation*} % 如果附录中的公式不想让它出现在公式索引中,那就请 % 用 equation* \left\{\begin{array}{l} \max \,\,f(x)\\%[0.1 cm] \mbox{subject to:} \\%[0.1 cm] \qquad g_j(x)\le 0,\quad j=1,2,\cdots,p \end{array}\right. \end{equation*} which maximizes a real-valued function $f$ of $x=(x_1,x_2,\cdots,x_n)$ subject to a set of constraints. \newcommand\Real{\mathbf{R}} \newtheorem{mpdef}{Definition}[chapter] \begin{mpdef} In SOP, we call $x$ a decision vector, and $x_1,x_2,\cdots,x_n$ decision variables. The function $f$ is called the objective function. The set \begin{equation*} S=\left\{x\in\Real^n\bigm|g_j(x)\le 0,\,j=1,2,\cdots,p\right\} \end{equation*} is called the feasible set. An element $x$ in $S$ is called a feasible solution. \end{mpdef} \newtheorem{mpdefop}[mpdef]{Definition} \begin{mpdefop} A feasible solution $x^*$ is called the optimal solution of SOP if and only if \begin{equation} f(x^*)\ge f(x) \end{equation} for any feasible solution $x$. \end{mpdefop} One of the outstanding contributions to mathematical programming was known as the Kuhn-Tucker conditions~\eqref{eq:ktc}. In order to introduce them, let us give some definitions. An inequality constraint $g_j(x)\le 0$ is said to be active at a point $x^*$ if $g_j(x^*)=0$. A point $x^*$ satisfying $g_j(x^*)\le 0$ is said to be regular if the gradient vectors $\nabla g_j(x)$ of all active constraints are linearly independent. Let $x^*$ be a regular point of the constraints of SOP and assume that all the functions $f(x)$ and $g_j(x),j=1,2,\cdots,p$ are differentiable. If $x^*$ is a local optimal solution, then there exist Lagrange multipliers $\lambda_j,j=1,2,\cdots,p$ such that the following Kuhn-Tucker conditions hold, \begin{equation} \label{eq:ktc} \left\{\begin{array}{l} \nabla f(x^*)-\sum\limits_{j=1}^p\lambda_j\nabla g_j(x^*)=0\\%[0.3cm] \lambda_jg_j(x^*)=0,\quad j=1,2,\cdots,p\\%[0.2cm] \lambda_j\ge 0,\quad j=1,2,\cdots,p. \end{array}\right. \end{equation} If all the functions $f(x)$ and $g_j(x),j=1,2,\cdots,p$ are convex and differentiable, and the point $x^*$ satisfies the Kuhn-Tucker conditions \eqref{eq:ktc}, then it has been proved that the point $x^*$ is a global optimal solution of SOP. \subsection{Linear Programming} \label{sec:lp} If the functions $f(x),g_j(x),j=1,2,\cdots,p$ are all linear, then SOP is called a \emph{linear programming}. The feasible set of linear is always convex. A point $x$ is called an extreme point of convex set $S$ if $x\in S$ and $x$ cannot be expressed as a convex combination of two points in $S$. It has been shown that the optimal solution to linear programming corresponds to an extreme point of its feasible set provided that the feasible set $S$ is bounded. This fact is the basis of the \emph{simplex algorithm} which was developed by Dantzig as a very efficient method for solving linear programming. \begin{table}[ht] \centering \centering \caption{This is an example for table} \label{tab:badtabular2} \begin{tabular}[c]{|m{1.5cm}|c|c|c|c|c|c|}\hline \multicolumn{2}{|c|}{Network Topology} & \# of nodes & \multicolumn{3}{c|}{\# of clients} & Server \\\hline GT-ITM & Waxman Transit-Stub & 600 & \multirow{2}{2em}{2\%}& \multirow{2}{2em}{10\%}& \multirow{2}{2em}{50\%}& \multirow{2}{1.2in}{Max. Connectivity}\\\cline{1-3} \multicolumn{2}{|c|}{Inet-2.1} & 6000 & & & &\\\hline \multirow{2}{1.5cm}{Xue} & Rui & Ni &\multicolumn{4}{c|}{\multirow{2}*{\thuthesis}}\\\cline{2-3} & \multicolumn{2}{c|}{ABCDEF} &\multicolumn{4}{c|}{} \\\hline \end{tabular} \end{table} Roughly speaking, the simplex algorithm examines only the extreme points of the feasible set, rather than all feasible points. At first, the simplex algorithm selects an extreme point as the initial point. The successive extreme point is selected so as to improve the objective function value. The procedure is repeated until no improvement in objective function value can be made. The last extreme point is the optimal solution. \subsection{Nonlinear Programming} If at least one of the functions $f(x),g_j(x),j=1,2,\cdots,p$ is nonlinear, then SOP is called a \emph{nonlinear programming}. A large number of classical optimization methods have been developed to treat special-structural nonlinear programming based on the mathematical theory concerned with analyzing the structure of problems. \begin{figure}[h] \centering \includegraphics{thu-lib-logo.pdf} \caption{This is an example for figure.} \label{tab:badfigure2} \end{figure} Now we consider a nonlinear programming which is confronted solely with maximizing a real-valued function with domain $\Real^n$. Whether derivatives are available or not, the usual strategy is first to select a point in $\Real^n$ which is thought to be the most likely place where the maximum exists. If there is no information available on which to base such a selection, a point is chosen at random. From this first point an attempt is made to construct a sequence of points, each of which yields an improved objective function value over its predecessor. The next point to be added to the sequence is chosen by analyzing the behavior of the function at the previous points. This construction continues until some termination criterion is met. Methods based upon this strategy are called \emph{ascent methods}, which can be classified as \emph{direct methods}, \emph{gradient methods}, and \emph{Hessian methods} according to the information about the behavior of objective function $f$. Direct methods require only that the function can be evaluated at each point. Gradient methods require the evaluation of first derivatives of $f$. Hessian methods require the evaluation of second derivatives. In fact, there is no superior method for all problems. The efficiency of a method is very much dependent upon the objective function. \subsection{Integer Programming} \emph{Integer programming} is a special mathematical programming in which all of the variables are assumed to be only integer values. When there are not only integer variables but also conventional continuous variables, we call it \emph{ mixed integer programming}. If all the variables are assumed either 0 or 1, then the problem is termed a \emph{zero-one programming}. Although integer programming can be solved by an \emph{exhaustive enumeration} theoretically, it is impractical to solve realistically sized integer programming problems. The most successful algorithm so far found to solve integer programming is called the \emph{branch-and-bound enumeration} developed by Balas (1965) and Dakin (1965). The other technique to integer programming is the \emph{cutting plane method} developed by Gomory (1959). \hfill\textit{Uncertain Programming\/}\quad(\textsl{BaoDing Liu, 2006.2}) \bibliographystyle{plainnat} \bibliography{ref/refs,ref/appendix} \end{survey}