随机环境中马氏链的平稳分布(英文)

本文引入了随机环境中马氏链平稳分布的概念. 在合适的条件下, 给出了随机环境中马氏链的平稳分布存在的一些充分条件. 特别地, 讨论了Cogburn链的平稳分布存在性问题. 同时, 构造了一个随机环境中马氏链的例子, 它的平稳分布是存在的.     

关于树指标二阶齐次马氏链的等价定义

树指标随机过程是近年来概率论的研究方向之一,已引起了概率论、物理学、计算机等学科的广泛关注,国内外关于树指标随机过程的研究已经取得了一定的成果.树指标随机过程中的一类重要的模型就是树指标马氏链.Benjiamini和Peres首先给出了树指标马氏链的定义.杨卫国、陈晓雪和王豹给出了树指标一阶马氏链的等价定义.杨卫国等又研究了树指标马氏链强极限定理.为了更有效的研究树指标随机过程,本文给出树指标二阶齐次马氏链的等价定义,并证明其等价性.     

关于随机环境中树指标马氏链的定义及存在性

给出了离散状态下随机环境中树指标马氏链的定义,它是树指标马氏链概念的推广,也是随机环境中马氏链概念的推广.文章同时研究其若干等价定理,证明了随机环境中树指标马氏链的存在性,以及马氏环境中树指标马氏链与树指标马氏双链的等价性.     

基于马氏链拟合的一种非负变权组合预测算法及其应用

通过马氏链拟合的方法求取一种新的非负时变权组合预测算法公式.主要工作是:一、对组合预测问题以最小误差为准则给出了马氏链的状态和状态概率初步估计;二、用马氏链拟合状态概率分布时变规律,通过约束多元自回归模型导出了一步转移概率阵的LS解;三、给出一种非负时变权组合预测公式并举一应用实例.     

模拟退火算法改进综述及参数探究

回顾模拟退火算法流程,对模拟退火算法现有的改进方法进行了系统的总结与评价.将模拟退火算法应用于求解Sobol’g函数的最小值,进而对模拟退火算法的三个关键参数:降温函数、初末温和马氏链长度进行探究.     

从p-m链到随机环境中的马氏链

第一节引进了p-m链的概念,并用之构造了与它相应的随机环境中的马氏链和绕积马氏链.第二节引进了一系列与随机环境中的马氏链相关的概率特性函数,并得到了这些函数之间的一系列关系.这些结果是经典马氏链的相应结果的一般化,它们在随机环境中的马氏链的极限理论的研究中是很有用的.     

随机环境中马氏链的周期性和常返性

研究了随机环境中马氏链的周期性,引入了随机环境中马氏链的正常返和零常返,利用状态的周期讨论了随机环境中马氏链的正常返性,给出了状态正常返的若干充分条件,从而推广了经典马氏链的相应结论.     

随机环境中马氏链的状态性质

本文研究了随机环境中马氏链的状态性质, 利用乘积空间的正则本质性和不可约性得到了随机环境中马氏链弱常返的充分条件.得到了随机环境中马氏链弱常返的充分条件.     

肖争艳等： 绕积马氏链的状态分类

该文给出了绕积马氏链的特征数和状态的定义, 利用一般马氏链的理论讨论了随机环 境中的马氏链的各种状态的特征以及各类状态之间的联系, 还给出了在联合空间不可分解且 正则本质的条件下, 状态正则本质的充要条件. 最后举例说明了经典马氏链和随机环境中马氏链的状态的区别.     

马氏环境中树指标马氏链随机转移概率调和平均的强极限性质

本文研究了离散状态下随机环境中树指标马氏链,证明了该过程在概率空间中可以实现,同时阐明了马氏环境下树指标马氏链与树指标马氏双链的等价性.获得了有限状态下马氏环境中树指标马氏链的随机转移概率调和平均的强极限性质.     

Discrete sensor placement problems in distribution networks

We consider the problem of placing sensors in a network to detect and identify thesource of any contamination. We consider two variants of this problem:

(1) sensor-constrained: we are allowed a fixed number of sensors and want to minimize contaminationdetection time; and

(2) time-constrained: we must detect contamination within a given time limit and want to minimize the number of sensors required.

Our main results are as follows. First, we give a necessary and sufficient condition for source identification.Second, we show that the sensor and time constrained versions of the problem are polynomially equivalent. Finally, we show that the sensor-constrained version of the problem is polynomially equivalent to the asymmetric k-center problem and that the time-constrained version of the problem is polynomially equivalent to the dominating set problem.     

Solving some optimal path planning problems using an approach based on measure theory

In this paper we solve a collection of optimal path planning problems using a method based on measure theory. First we consider the problem as an optimization problem and then we convert it to an optimal control problem by defining some artificial control functions. Then we perform a metamorphosis in the space of problem. In fact we define an injection between the set of admissible pairs, containing the control vector function and a collision-free path defined on free space and the space of positive Radon measures. By properties of this kind of measures we obtain a linear programming problem that its solution gives rise to constructing approximate optimal trajectory of the original problem. Some numerical examples are proposed.     

Algorithms for the computation of functionals defined on the solution of a discrete ill-posed problem

We study a linear, discrete ill-posed problem, by which we mean a very ill-conditioned linear least squares problem. In particular we consider the case when one is primarily interested in computing a functional defined on the solution rather than the solution itself. In order to alleviate the ill-conditioning we require the norm of the solution to be smaller than a given constant. Thus we are lead to minimizing a linear functional subject to two quadratic constraints. We study existence and uniqueness for this problem and show that it is essentially equivalent to a least squares problem with a linear and a quadratic constraint, which is easier to handle computationally. Efficient algorithms are suggested for this problem.     

A Bicriterial Optimization Problem of Antenna Design

In this paper we consider a special optimization problem withtwo objectives which arises in antenna theory. It is shown that thisabstract bicriterial optimization problem has at least one solution.Discretized versions of this problem are also discussed, and therelationships between these finite dimensional problems and the infinitedimensional problem are investigated. Moreover, we presentnumerical results for special parameters using a multiobjectiveoptimization method.     

Global Method for Monotone Variational Inequality Problems with Inequality Constraints

We consider optimization methods for monotone variational inequality problems with nonlinear inequality constraints. First, we study the mixed complementarity problem based on the original problem. Then, a merit function for the mixed complementarity problem is proposed, and some desirable properties of the merit function are obtained. Through the merit function, the original variational inequality problem is reformulated as simple bounded minimization. Under certain assumptions, we show that any stationary point of the optimization problem is a solution of the problem considered. Finally, we propose a descent method for the variational inequality problem and prove its global convergence.     

图论与矩形对角线法在钻井布局优化设计中的应用

本对钻井布局问题的研究,首先给出图论模型对问题1得出最多可利用4口旧井,井号为2、4、5、10。利用矩形对角线法对问题2得出最多可利用6口旧井,井号为1、6、7、8、9、11。同时利用矩形对角线法给出判定这些井均可利用的条件和算法。     

Perturbation analysis for mixed least squares–total least squares problems

In many linear parameter estimation problems, one can use the mixed least squares–total least squares (MTLS) approach to solve them. This paper is devoted to the perturbation analysis of the MTLS problem. Firstly, we present the normwise, mixed, and componentwise condition numbers of the MTLS problem, and find that the normwise, mixed, and componentwise condition numbers of the TLS problem and the LS problem are unified in the ones of the MTLS problem. In the analysis of the first‐order perturbation, we first provide an upper bound based on the normwise condition number. In order to overcome the problems encountered in calculating the normwise condition number, we give an upper bound for computing more effectively for the MTLS problem. As two estimation techniques for solving the linear parameter estimation problems, interesting connections between their solutions, their residuals for the MTLS problem, and the LS problem are compared. Finally, some numerical experiments are performed to illustrate our results.     

A study of mixed discrete bilevel programs using semidefinite and semi-infinite programming

In this paper, we study the bilevel programming problem with discrete polynomial lower level problem. We start by transforming the problem into a bilevel problem comprising a semidefinite program (SDP for short) in the lower level problem. Then, we are able to deduce some conditions of existence of solutions for the original problem. After that, we again change the bilevel problem with SDP in the lower level problem into a semi-infinite program. With the aid of the exchange technique, for simple bilevel programs, an algorithm for computing a global optimal solution is suggested, the convergence is shown, and a numerical example is given.     

Nonconvex and relaxed infinite-horizon optimal control problems

In this paper, we consider the Lagrange problem of optimal control defined on an unbounded time interval in which the traditional convexity hypotheses are not met. Models of this form have been introduced into the economics literature to investigate the exploitation of a renewable resource and to treat various aspects of continuous-time investment. An additional distinguishing feature in the models considered is that we do not assume a priori that the objective functional (described by an improper integral) is finite, and so we are led to consider the weaker notions of overtaking and weakly overtaking optimality. To treat these models, we introduce a relaxed optimal control problem through the introduction of chattering controls. This leads us naturally to consider the relationship between the original problem and the convexified relaxed problem. In particular, we show that the relaxed problem may be viewed as a limiting case for the original problem. We also present several examples demonstrating the applicability of our results.     

Non-crossing matchings of points with geometric objects

Given an ordered set of points and an ordered set of geometric objects in the plane, we are interested in finding a non-crossing matching between point–object pairs. In this paper, we address the algorithmic problem of determining whether a non-crossing matching exists between a given point–object pair. We show that when the objects we match the points to are finite point sets, the problem is NP-complete in general, and polynomial when the objects are on a line or when their size is at most 2. When the objects are line segments, we show that the problem is NP-complete in general, and polynomial when the segments form a convex polygon or are all on a line. Finally, for objects that are straight lines, we show that the problem of finding a min-max non-crossing matching is NP-complete.