An optimal critical level policy for inventory systems with two demand classes

Traditional inventory systems treat all demands of a given item equally. This approach is optimal if the penalty costs of all customers are the same, but it is not optimal if the penalty costs are different for different customer classes. Then, demands of customers with high penalty costs must be filled before demands of customers with low penalty costs. A commonly used inventory policy for dealing with demands with different penalty costs is the critical level inventory policy. Under this policy demands with low penalty costs are filled as long as inventory is above a certain critical level. If the inventory reaches the critical level, only demands with high penalty costs are filled and demands with low penalty costs are backordered. In this article, we consider a critical level policy for a periodic review inventory system with two demand classes. Because traditional approaches cannot be used to find the optimal parameters of the policy, we use a multidimensional Markov chain to model the inventory system. We use a sample path approach to prove several properties of this inventory system. Although the cost function is not convex, we can build on these properties to develop an optimization approach that finds the optimal solution. We also present some numerical results. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Optimal sensor placement for underwater threat detection

The optimization framework for optimal sensor placement for underwater threat detection has been developed. It considers single‐period and multiperiod detection models, each of which includes two components: detection algorithm and optimization problem for sensor placement. The detection algorithms for single‐period and multiperiod models are based on likelihood ratio and sequential testing, respectively. For the both models, the optimization problems use the principle of superadditive coverage, which is closely related to energy‐based and information‐based approaches. An algorithm for quasi‐regular sensor placement approximating solutions to the optimization problems has been developed based on corresponding continuous relaxations and a criterion for its applicability has been obtained. Numerical experiments have demonstrated that the algorithm consistently outperforms existing optimization techniques for optimal sensor placement.© 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

大型地下车库消防安全隐患及对策研究

从大型地下车库的火灾危险性及自身特点出发,分析了常见的火灾隐患及影响火灾蔓延的重要因素,提出了大型地下车库的消防设计要求,并从建立组织制度、加强消防宣传、完善消防设施、开展防火检查、加强灭火演习等几个方面提出了消防安全管理对策,以减少或避免火灾的发生.     

治安管理学实践教学应用研究

在《治安管理学》教学中加强实践教学,是由其学科特点与授课对象特点决定的,也是为了提高学员第一任职能力与实现教学相长的需要。应通过课堂实践教学、校内实践模拟教学与校外实践基地相结合的方式,加强实践教学在《治安管理学》教学中的具体应用,对于实现《治安管理学》教学目标与我院人才培养目标具有重要意义。     

打击特殊群体贩毒活动现状及对策研究

近年来,随着我国堵截、打击毒品犯罪力度的持续加大,境内外贩毒集团组织实施大宗毒品贩运的能力明显减弱,毒品犯罪快速蔓延的势头得到初步遏制。但是,贩毒集团为逃避打击、降低风险,不断变换犯罪手法,钻法律漏洞,特别是组织、利用特殊人群进行贩毒活动的现象日益增多,并呈现出家族化、规模化的趋势,而公安机关在打击特殊群体贩毒活动中,由于立法和执法等多方面的原因,还面临法律、查缉、羁押、案件处理等一系列的问题。执法实践要求运用法律、经济、行政、教育、文化等措施,综合治理特殊群体贩毒问题,努力从源头上遏制特殊人群贩毒问题的滋生、蔓延。     

计算机档案文件管理系统的设计与实现

计算机的应用和普及对办公自动化起到了极大的推动作用。针对“文档一体化”的提出,档案管理工作的改革需要新的计算机档案文件管理系统。以Visual FoxPro为开发工具,分别从需求分析、系统实现、主要功能设计和系统应用与改进四个角度,对计算机档案文件管理系统进行阐述和研究。     

对高校管理信息化建设的调查与分析

高校管理信息化是一个包含着技术、组织、理念等多种因素的综合体系,对高校和社会发展均具有重大意义。目前,各高校对于管理信息化建设在目标定位、建设措施、组织实施等方面都存在不足。本文对石河子大学高校管理信息化建设现状进行了调查分析,针对学校存在的问题提出了抓目标定位、整体规划、技术支持等重要环节,以推动高校管理信息化建设的纵深发展。     

磁调制式电流传感器的数学模型与性能分析

从基本的电路理论和铁磁学原理出发,推导了磁调制式电流传感器的数学模型,特别是对正弦电压激励下的传感器的输出和灵敏度进行了研究,为磁调制式电流传感器的设计打下了基础.     

通用装备机械液压系统综合检测试验平台运用问题研究

论述了通用装备机械液压系统综合检测试验平台的功能、组成结构、特点及对平台的初步认识,从使用时机、平台的编配、平台的质量管理、平台保障数据库建设、平台的应用等方面,对平台的运用问题进行了研究,并从平时保障的角度对平台提出改进建议。     

数据挖掘与数据融合相结合的异类信息融合*

针对组网系统中的信息样式多、模糊性强等特点,介绍了分布式异类传感器组网系统及其特点,将数据挖掘中的知识发现理论与数据融合的知识应用理论相结合,建立了异类信息综合处理的集成模型。并提出了基于模糊神经网络的数据挖掘算法,增强了集成模型的自学习性能。模型有效地提高了异类传感器组网系统的智能化、自动化能力。