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91.
Discrete‐time queues with D‐MAP arrival process are more useful in modeling and performance analysis of telecommunication networks based on the ATM environment. This paper analyzes a finite‐buffer discrete‐time queue with general bulk‐service rule, wherein the arrival process is D‐MAP and service times are arbitrarily and independently distributed. The distributions of buffer contents at various epochs (departure, random, and prearrival) have been obtained using imbedded Markov chain and supplementary variable methods. Finally, some performance measures such as loss probability and average delay are discussed. Numerical results are also presented in some cases. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 345–363, 2003. 相似文献
92.
ABSTRACTThis study seeks to evaluate the threat of malicious chemical use by non-state actors. It finds that non-state actors have primarily turned to ready-to-use crude chemical weapons (CW) instead of traditional CW agents. Interestingly, the worst crude CW attacks have been more destructive than those employing traditional CW. Scenarios for catastrophic consequences exist, but chemical attacks have typically been used to accomplish tactical goals, which leverage psychological and economic impacts. Therefore, successful efforts to counter CW proliferation by non-state actors must be substantially different from those targeting states. 相似文献
93.
基于模糊数的防空C3I系统效能评估 总被引:1,自引:0,他引:1
根据模糊数适于量化模糊信息的特点,运用模糊集理论,提出了一种基于模糊数的模糊综合评估方法.通过计算被评估系统效能的模糊数,将问题转化为模糊数的排序问题,并给出了采用该方法对防空C3I系统效能评估的模型及实现步骤.该方法能对防空C3I系统的效能指标进行合理的量化处理,较好地解决了防空C3I系统效能评估问题,通过计算实例验证了该方法的正确性和实用性. 相似文献
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In this paper, a branch-and-bound procedure is presented for treating the general knapsack problem. The fundamental notion of the procedure involves a variation of traditional branching strategies as well as the incorporation of penalties in order to improve bounds. Substantial computational experience has been obtained, the results of which would indicate the feasibility of the procedure for problems of large size. 相似文献
96.
Richard L. Nolan 《海军后勤学研究》1970,17(3):359-372
Systems analysis office titles have permeated both government and business organization charts in recent years. Systems analysis as a discipline, however, even though increasingly accepted, has eluded precise definition. For the most part, it has been loosely described as “quantitative common sense” and “the general application of the scientific method.” Emphasis is placed upon the application of eclectic disciplines to a wide variety of problems. Concepts and techniques have been drawn heavily from economics, mathematics, and political science. In the Department of Defense, systems analysis has been used extensively in the evaluation of weapon systems during the last 9 years. During the 1960's, it provided the underlying concepts for the control system PPBS (Planning-Programming-Budgeting System). This article traces the origins of systems analysis within the Department of Defense and describes and analyzes the application of the technique. Although there always exists disagreement, it is generally accepted that the origin of systems analysis coincided with the inception of R. S. McNamara's administration of the Department of Defense. McNamara organized the Systems Analysis office under Mr. Charles Hitch, who had previously developed many basic systems analysis concepts at project RAND. From Hitch's basic concepts, the approach became increasingly sophisticated in evaluating complex weapons systems. Coincidently, the organizational procedures for implementing systems analysis also evolved. Under the current Department of Defense administration, the new organizational procedures emerging are contrasted with the old. 相似文献
97.
Tobias Brueggemann Johann L. Hurink Tjark Vredeveld Gerhard J. Woeginger 《海军后勤学研究》2011,58(8):795-803
We investigate the quality of local search heuristics for the scheduling problem of minimizing the makespan on identical parallel machines. We study exponential size neighborhoods (whose size grows exponentially with the input length) that can be searched in polynomial time, and we derive worst‐case approximation guarantees for the local optima of such neighborhoods. The so‐called split neighborhood splits a feasible schedule into two layers, and then recombines the two layers by finding a perfect matching. We show that the makespan of every local optimum for split is at most a factor of 2 away from the globally optimal makespan. We then combine the split neighborhood with two neighborhoods from the literature. The combination of split with the jump neighborhood only marginally improves the approximation guarantee, whereas the combination with the lexicographic‐jump neighborhood decreases the approximation guarantee from 2 to 3/2. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
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99.
A process control scheme is developed in which decisions as to the frequency of sampling are made based upon the choice of an Average Outgoing Quality Limit. The scheme utilizes plotted points on a U-control chart for defects and the theory of runs to determine when to switch among Reduced, Normal, Tightened, and 100 percent inspection. The scheme is formulated as a semi-Markov process to derive steady stale equations for the probabilities of being in Reduced, Normal, Tightened, or 100 percent inspection and for Average Outgoing Quality and Average Fraction Inspected. The resulting system and the computer programs used to derive it are discussed. 相似文献
100.