Optimal source placement for point coverage in active multistatic sonar networks

The allocation of underwater sensors for tracking, localization, and surveillance purposes is a fundamental problem in anti-submarine warfare. Inexpensive passive receivers have been heavily utilized in recent years; however, modern submarines are increasingly quiet and difficult to detect with receivers alone. Recently, the idea of deploying noncollocated sources and receivers has emerged as a promising alternative to purely passive sensor fields and to traditional sonar fields composed of collocated sources and receivers. Such a multistatic sonar network carries a number of advantages, but it also brings increased system complexity resulting from its unusual coverage patterns. In this work, we study the problem of optimally positioning active multistatic sonar sources for a point coverage application where all receivers and points of interest are fixed and stationary. Using a definite range sensor model, we formulate exact methods and approximation algorithms for this problem and compare these algorithms via computational experiments. We also examine the performance of these algorithms on a discrete approximation of a continuous area coverage problem and find that they offer a significant improvement over two types of random sensor deployment.     

Mathematical formulation and heuristic algorithm for the block relocation and loading problem

This study considers the block relocation and loading problem in container terminals. The optimal loading sequence and relocation location are simultaneously decided on the basis of the desired ship‐bay and initial yard space configuration. An integer linear programming model is developed to minimize the number of relocations in the yard space on the basis of no shifts in the ship bay. The accuracy of the model is tested on small‐scale scenarios by using CPLEX. Considering the problem size in the real world, we present a rule‐based heuristic method that is combined with a mathematical model for the removal, loading, and relocation operations. The influence of rules on algorithm performance is also analyzed, and the heuristic algorithm is compared with different types of algorithms in the literature. The extensive numerical experiments show the efficiency of the proposed heuristic algorithm.     

Noncooperative cost spanning tree games with budget restrictions

We extend the noncooperative game associated with the cost spanning tree problem introduced by Bergantiños and Lorenzo (Math Method Oper Res 59(2004), 393–403) to situations where agents have budget restrictions. We study the Nash equilibria, subgame perfect Nash equilibria, and strong Nash equilibria of this game. © 2008 Wiley Periodicals, Inc. Naval Research Logistics 2008     

公安派出所消防监督工作现状及问题分析

结合公安派出所消防监督工作现状,深入分析了当前在落实派出所消防监督管理职责方面存在的突出问题,就进一步提高和加强基层公安派出所消防监督管理工作提出了具体意见和建议。     

部队基层思想政治教育中亟待解决的几个问题

贯彻落实新的《军队思想政治教育大纲》,部队基层必须着力解决重视不够、摆位不正的问题,转变与时代不相符的思想政治教育观念,创新和改进思想政治教育的内容和手段,提升思想政治教育队伍的综合素质,创新和完善思想政治教育机制,进一步优化思想政治教育环境。     

求解旅行商问题的两步法

基于度约束最小树算法提出了一个解决旅行商问题的算法（即两步法）,针对这一算法我们进行了大量的数据实验,数据实验表明算法是非常有效的。     

匈牙利算法在多目标分配中的应用

在多目标攻击决策中 ,根据 Harold提出的目标优势函数 ,分析了使所有目标机的总优势函数为指派问题 ,运用匈牙利算法对 n对 n的最优目标分配指派问题进行求解 ,并把它推广至 n对 m的多目标分配中。仿真结果表明匈牙利算法对于此类多目标分配指派问题的求解是十分有效的。     

火灾统计失实问题的现状及对策

以四川省为例介绍火灾统计失实的情况 ,并分析火灾统计失实问题的原因 ,提出纠正火灾统计失实问题的工作意见。     

数学名题与HPM研究

数学名题对于数学教育和HPM研究都具有重要的价值。法国数学教育家、数学史家史威兹提出,在数学问题配置与求解中可选择历史上不同时期、不同文化的一些数学名题。在此基础上,我们提出了HPM视角下的问题解决教学这一新课题。HPM视角下的问题解决教学侧重于对历史上所用各种数学思想方法进行比较分析,使学生了解不同文化背景中的数学思考方式,其目的在于培养学生数学洞察力,启发数学思想方法,提升数学思维能力,并可在社会历史文化与数学思维的双重醺陶下,获得数学认知活动的文化意义,在数学教育中实践多元文化关怀的理想。     

基于遗传算法优化网络权值的装箱问题研究

通过对Hopfield网络模型的研究,把一种类型的装箱问题转化成Hopfield网络模型,再利用遗传算法优化Hopfield网络中的连接权值,形成混合优化算法求解装箱问题,最后通过实例验证了该算法的有效性。