Analysis and optimal design of discrete order picking technologies along a line

Order picking accounts for most of the operating expense of a typical distribution center, and thus is often considered the most critical function of a supply chain. In discrete order picking a single worker walks to pick all the items necessary to fulfill a single customer order. Discrete order picking is common not only because of its simplicity and reliability, but also because of its ability to pick orders quickly upon receipt, and thus is commonly used by e‐commerce operations. There are two primary ways to reduce the cost (walking distance required) of the order picking system. First is through the use of technology—conveyor systems and/or the ability to transmit order information to pickers via mobile units. Second is through the design—where best to locate depots (where workers receive pick lists and deposit completed orders) and how best to lay out the product. We build a stochastic model to compare three configurations of different technology requirements: single‐depot, dual‐depot, and no‐depot. For each configuration we explore the optimal design. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

被掩护地面固定目标不受空中打击分析

重点分析了被掩护地面固定目标不受空中打击的相关因素,并定量地分析了敌空袭兵器攻击地面被掩护目标时所需的数量,从而为地面防空建立最佳的防空部署提供依据。因为防空兵群对空袭兵器的射击次数与防空兵群的杀伤区面积成线性关系,所以在探讨如何部署防空兵力时,以防空兵群的杀伤区面积为准则来建立线性规划模型。     

攻击机无源侦察定位原理研究

机载无源定位是判断反辐射导弹是否位于攻击区的根据,阐述了装挂反辐射导弹的攻击机应用改进雷达告警器或雷达告警器交联反辐射弹对有威胁的辐射目标无源定位的原理,并对其定位精度进行了研究。     

基于多传感器优化布站的干扰目标定位模型

提出了传感器的优化部署模型 ,利用多传感器对干扰目标实现三角交叉定位 ,并给出了选择用于定位的传感器的数学模型。     

潜艇鱼雷武器多通道射击控制研究

在论述潜艇武器系统演变到武器通道的客观必然和技术特点的基础上,分析了反鱼雷技术在海上攻防对抗过程中给潜艇鱼雷攻击带来的困难。为了弥补鱼雷同一种自导方式齐射在对抗阶段存在的不足,提出了潜艇鱼雷武器多通道射击控制(或多自导方式鱼雷混合齐射)的概念。研究了实现鱼雷混合自导方式齐射所涉及的技术环节,给出了解决齐射各雷相互干扰、射击参数解算等问题的相应方法和模型。     

机房漏水检测与精确定位装置研究

机房漏水是危及精密信息设备长期稳定可靠运行的重大安全隐患。为了解决传统定位装置难以实现漏水点精确定位的问题,从传感电缆的检漏原理出发,利用分压补偿原理,通过STEP7软件编程,设计了一个结合自检、漏水检测和漏水定位3种功能的机房漏水检测与定位装置。在此基础上搭建了实验系统,经测试实验,结果表明短距离定位精度可以达到1．70％,从而证实了该装置检测的有效性和定位的精确性。     

磷虾群免疫粒子滤波的机载单站无源定位算法

为了进一步提高机载单站无源定位的精度,将磷虾群优化思想引入到粒子滤波的重采样阶段,提出了一种磷虾群免疫粒子滤波算法。该算法利用磷虾的受诱导运动、觅食以及随机扩散行为,将粒子导向高似然区域,有效缓解了粒子退化问题。同时,其采用了人工免疫算法的变异操作,避免了早熟现象的出现,提高了粒子的多样性,克服了粒子贫化问题。仿真结果表明,新算法改善了机载单站无源定位的定位精度以及收敛速度。     

基于人眼定位算法的驾驶员疲劳检测

研究了一种基于人眼定位的驾驶员疲劳检测方法。采用一种结合眼睛灰度及形状信息的人眼定位方法,进行眼睛准确定位,然后用处于睁开状态的眼睛模板与待测图像中的眼睛模板相匹配,对一定时间间隔内采集的图像进行人眼状态的开闭判定,由此判断驾驶员是否疲劳。实验表明,该方法可快速有效地进行驾驶员疲劳检测。     

Discriminating between the Weibull and log‐normal distributions

Log‐normal and Weibull distributions are the most popular distributions for modeling skewed data. In this paper, we consider the ratio of the maximized likelihood in choosing between the two distributions. The asymptotic distribution of the logarithm of the maximized likelihood ratio has been obtained. It is observed that the asymptotic distribution is independent of the unknown parameters. The asymptotic distribution has been used to determine the minimum sample size required to discriminate between two families of distributions for a user specified probability of correct selection. We perform some numerical experiments to observe how the asymptotic methods work for different sample sizes. It is observed that the asymptotic results work quite well even for small samples also. Two real data sets have been analyzed. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Facility location models for immobile servers with stochastic demand

This paper presents several models for the location of facilities subject to congestion. Motivated by applications to locating servers in communication networks and automatic teller machines in bank systems, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. We consider this problem from three different perspectives, that of (i) the service provider (wishing to limit costs of setup and operating servers), (ii) the customers (wishing to limit costs of accessing and waiting for service), and (iii) both the service provider and the customers combined. In all cases, a minimum level of service quality is ensured by imposing an upper bound on the server utilization rate at a service facility. The latter two perspectives also incorporate queueing delay costs as part of the objective. Some cases are amenable to an optimal solution. For those cases that are more challenging, we either propose heuristic procedures to find good solutions or establish equivalence to other well‐studied facility location problems. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.