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101.
攻击型航空综合体作战效能分析的模型构成   总被引:2,自引:0,他引:2  
给出了航空综合体及其作战效能的基本概念,并根据攻击型航空综合体作战特点及作战过程,阐述了对其作战效能进行分析时所需要建立的数学模型及各自应具有的主要功能  相似文献   
102.
In this paper, we present a physics-based stochastic model to investigate vessel casualties resulting from tanker traffic through a narrow waterway. A state-space model is developed to represent the waterway and the location of vessels at a given time. We first determine the distribution of surface current at a given location of the waterway depending on channel geometry, bottom topography, boundary conditions, and the distribution of wind. Then we determine the distribution of the angular drift for a given vessel travelling at a given location of a waterway. Finally, we incorporate the drift probabilities and random arrival of vessels into a Markov chain model. By analyzing the time-dependent and the steady-state probabilities of the Markov chain, we obtain risk measures such as the probability of casualty at a given location and also the expected number of casualties for a given number of vessels arriving per unit time. Analysis of the Markovian model also yields an analytical result that shows that the expected number of casualties is proportional to square of the tanker arrival rate. We present our methodology on an experimental model of a hypothetical narrow waterway. © 1999 John Wiley & Sons, Inc. Naval Reseach Logistics 46: 871–892, 1999  相似文献   
103.
A classical and important problem in stochastic inventory theory is to determine the order quantity (Q) and the reorder level (r) to minimize inventory holding and backorder costs subject to a service constraint that the fill rate, i.e., the fraction of demand satisfied by inventory in stock, is at least equal to a desired value. This problem is often hard to solve because the fill rate constraint is not convex in (Q, r) unless additional assumptions are made about the distribution of demand during the lead‐time. As a consequence, there are no known algorithms, other than exhaustive search, that are available for solving this problem in its full generality. Our paper derives the first known bounds to the fill‐rate constrained (Q, r) inventory problem. We derive upper and lower bounds for the optimal values of the order quantity and the reorder level for this problem that are independent of the distribution of demand during the lead time and its variance. We show that the classical economic order quantity is a lower bound on the optimal ordering quantity. We present an efficient solution procedure that exploits these bounds and has a guaranteed bound on the error. When the Lagrangian of the fill rate constraint is convex or when the fill rate constraint does not exist, our bounds can be used to enhance the efficiency of existing algorithms. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 635–656, 2000  相似文献   
104.
在投资组合各种模型中,具有偏好系数的投资组合模型是最重要的模型之一,对其求解的研究具有理论价值。本文利用矩阵分块理论对此模型进行了研究,并给出了此模型解存在的一个充分条件。  相似文献   
105.
The aim of this article is to evaluate how French Major Conventional Weapons (MCW) exports impact on the conflict intensity of recipient countries. The recent increase in French arms exports seems to contradict the French political discourse on the promotion of regional stability. We run zero-inflated ordered probit model in order to analyze the role of the arms trade on the intensity of civil conflicts in 144 countries from 1992 to 2014, using SIPRI and UCDP/PRIO data. Our results suggest that French MCW exports tended not to exacerbate intrastate conflicts during this period. This finding is robust to changes in the empirical framework. We propose two lines of explanations: France seems to be prone to choosing partners that respect human rights and selling more ‘defense-oriented’ MCW than the rest of the world.  相似文献   
106.
This article offers a comprehensive analysis of the database ‘Mémoire des hommes’, which is a record of more than 1 million French soldiers officially recognized as dead during the World War I (WWI). Integrating this source with the 1911 census, we evaluate the potential numbers of recruits by French regional department. From this, a model identifies the factors affecting the number of deaths. While demographic factors are the principal determinants, adding significant economic, political and spatial factors reduces the unexplained variance between regions and significantly improves the explanation of the disparity in the number of deaths by region.  相似文献   
107.
作战仿真模型体系结构的描述是一个复杂的问题,传统的方法难以清晰描述各要素之间的内在关系。采用解释结构模型的方法对模型体系中的继承、组合关系进行形式化建模,在对体系要素进行简化抽象的基础上,通过矩阵运算和逻辑推理完成对体系内所有要素的关系描述,能够实现对复杂模型体系的结构化描述和简洁化表达。  相似文献   
108.
从实践需求出发 ,建立了空中突击效果的预测模型 ,旨在对特定目标在某一时刻遭到突击后 ,预测其在任一后续时间点上所产生的突击效果 ,以便为计划人员有效使用战役突击力量提供可靠保证  相似文献   
109.
目前我国在安全疏散评价中采用的人员疏散模型和计算方法不尽相同,而对于同一种场景,不同疏散模型和计算方法存在较大差异性。通过同一种疏散场景不同疏散模型和计算结果的对比,验证了三种计算方法以及采用中西方人体参数的差异大小,为选择合理的安全疏散评估方法提供了指导。  相似文献   
110.
在装备采购项目组织流程设计中引入角色网络理论,构建装备采购项目组织流程设计的角色优化模型,从流程人员设计、工序设计和反馈设计等3个方面阐述角色优化模型用于流程设计的推导过程,并将该方法应用到某装备采购项目组织流程设计实践中。通过流程设计前后的对比分析,该模型能够有效进行装备采购项目组织流程设计,有着较强的推广和应用价值。  相似文献   
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