机载红外搜索跟踪系统

红外搜索和跟踪（ＩＲＳＴ） 系统是迅速探测红外威胁源的存在, 识别威胁源的种类,测定威胁源的方位并报警的一种光电系统。介绍了对机载ＩＲＳＴ的性能要求, 美国和欧洲等国对机载ＩＲＳＴ的研制及装备概况, 分析了今后机载ＩＲＳＴ系统的发展方向。     

基于参数稳态判定的两阶段序贯仿真分析策略

两阶段序贯分析方法是仿真(模拟)实验研究中的一种常用方法,它虽然可以通过控制实验给出符合精度要求的结果数据,但以其现有形式有时却无法避免冗余计算的存在和实验过早终止的可能.在回顾了现有终态仿真解算终止策略特点的基础上,分析了所需样本总数的估计值与当前可用样本间的变化关系,提出了一种基于参数稳态判定的改进两阶段序贯方法....     

新媒介：当代大学生思想政治教育的有效途径

随着信息技术的迅猛发展,新媒介对大学生的影响日益深刻。新媒介具有对大学生进行思想政治教育的先天优势,但新媒介环境下的思想政治教育危机也不容忽视。我们应当扬长避短,积极探索利用新媒介开展思想政治教育的新路径,不断提高思想政治教育的针对性和有效性。     

消防部队灭火救援行动中的灾情信息需求与分析

灾情信息是灭火及应急救援行动的关键因素,在救援行动中发挥重要作用。介绍了灾情信息的基本概念、具体内容和表现形式,详细分析了消防部队在灭火和应急救援行动中灾情信息的应用现状和发展方向,并对灾情信息的应用提出了部分改进建议,为灭火和应急救援的信息化建设提供技术支持。     

石化企业火灾事故原因调查方法和技术研究

根据石油化工企业生产特点,阐述了石油化工企业火灾现场特点、火灾事故调查的重点内容、调查采取的方法和技术以及事故调查当中的注意事项,为开展好石油化工企业火灾调查工作提供参考。     

Analysis of decentralized multi‐product pull systems with lost sales

We study a pull‐type, flexible, multi‐product, and multi‐stage production/inventory system with decentralized two‐card kanban control policies. Each stage involves a processor and two buffers with finite target levels. Production stages, arranged in series, can process several product types one at a time. Transportation of semi‐finished parts from one stage to another is performed in fixed lot sizes. The exact analysis is mathematically intractable even for smaller systems. We present a robust approximation algorithm to model two‐card kanban systems with batch transfers under arbitrary complexity. The algorithm uses phase‐type modeling to find effective processing times and busy period analysis to identify delays among product types in resource contention. Our algorithm reduces the effort required for estimating performance measures by a considerable margin and resolves the state–space explosion problem of analytical approaches. Using this analytical tool, we present new findings for a better understanding of some tactical and operational issues. We show that flow of material in small procurement sizes smoothes flow of information within the system, but also necessitates more frequent shipments between stages, raising the risk of late delivery. Balancing the risk of information delays vis‐à‐vis shipment delays is critical for the success of two‐card kanban systems. Although product variety causes time wasted in setup operations, it also facilitates relatively short production cycles enabling processors to switch from one product type to another more rapidly. The latter point is crucial especially in high‐demand environments. Increasing production line size prevents quick response to customer demand, but it may improve system performance if the vendor lead‐time is long or subject to high variation. Finally, variability in transportation and processing times causes the most damage if it arises at stages closer to the customer. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Quantifying the performance effects of idle time utilization in multiserver systems

In many practical multiserver queueing systems, servers not only serve randomly arriving customers but also work on the secondary jobs with infinite backlog during their idle time. In this paper, we propose a c‐server model with a two‐threshold policy, denoted by (e d), to evaluate the performance of this class of systems. With such a policy, when the number of idle servers has reached d (<c), then e (<d) idle agents will process secondary jobs. These e servers keep working on the secondary jobs until they find waiting customers exist in the system at a secondary job completion instant. Using the matrix analytic method, we obtain the stationary performance measures for evaluating different (e, d) policies. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.     

Managing components for assemble‐to‐order products with lead‐time‐dependent pricing: The full‐shipment model

We study a component inventory planning problem in an assemble‐to‐order environment faced by many contract manufacturers in which both quick delivery and efficient management of component inventory are crucial for the manufacturers to achieve profitability in a highly competitive market. Extending a recent study in a similar problem setting by the same authors, we analyze an optimization model for determining the optimal component stocking decision for a contract manufacturer facing an uncertain future demand, where product price depends on the delivery times. In contrast to our earlier work, this paper considers the situation where the contract manufacturer needs to deliver the full order quantity in one single shipment. This delivery requirement is appropriate for many industries, such as the garment and toy industries, where the economies of scale in transportation is essential. We develop efficient solution procedures for solving this optimization problem. We use our model results to illustrate how the different model parameters affect the optimal solution. We also compare the results under this full‐shipment model with those from our earlier work that allows for multiple partial shipments. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Constrained minimax optimization of continuous search efforts for the detection of a stationary target

Analytical resolution of search theory problems, as formalized by B.O. Koopman, may be applied with some model extension to various resource management issues. However, a fundamental prerequisite is the knowledge of the prior target density. Though this assumption has the definite advantage of simplicity, its drawback is clearly that target reactivity is not taken into account. As a preliminary step towards reactive target study stands the problem of resource planning under a min–max game context. This paper is related to Nakai's work about the game planning of resources for the detection of a stationary target. However, this initial problem is extended by adding new and more general constraints, allowing a more realistic modeling of the target and searcher behaviors. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Puzzle‐based storage systems

We introduce and develop models for a physical goods storage system based on the 15‐puzzle, a classic children's game in which 15 numbered tiles slide within a 4 × 4 grid. The objective of the game is to arrange the tiles in numerical sequence, starting from a random arrangement. For our purposes, the tiles represent totes, pallets, or even containers that must be stored very densely, and the objective is to maneuver items to an input–output point for retrieval or processing. We develop analytical results for storage configurations having a single empty location (as in the game) and experimental results for configurations with multiple empty locations. Designs with many empty locations can be made to form aisles, allowing us to compare puzzle‐based designs with traditional aisle‐based designs found in warehousing systems. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007