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181.
界定了通用装备机动抢修单元(人-装备-机工具-器材结合体)的内涵和外延,构建了通用装备机动抢修单元作业过程模型.通过EXTEND仿真平台定量评估了面向典型任务条件下通用装备(以车辆装备为例)机动抢修单元的作业效能。最后对仿真评估结果进行分析,提出了改进对策和建议。  相似文献   
182.
对单节点并联供水系统直接用伯努利方程、管道阻力特性和节点连续性方程建立了求解工况参数的一个新的数学模型,讨论了其解,列举了实际应用。  相似文献   
183.
从图书馆主动服务的理念入手,探讨利用网络开展主动服务的可能性,并结合对全国15所重点高校图书馆网站和实践开展的多种主动服务方式进行调查统计,分析总结其特点,由此得出对军校图书馆开展主动服务的启示。  相似文献   
184.
张剑芳  苏辰 《国防科技》2017,38(2):046-049
物流单证是物流系统之间数据交换的载体,是实现物流业务流程无缝衔接的条件。文章介绍了物流单证结构,研究了军事物流单证的信息交换过程,建立了军事物流单证的信息交换架构,探讨了军事物流单证信息查询和业务状态信息跟踪服务。  相似文献   
185.
针对现有的软件定义卫星网络中流表占用的三态内容寻址存储器空间不断增加,复杂的流表项查找、匹配过程导致路由转发效率降低,无法满足多样化应用需求的问题,提出基于神经网络的软件定义卫星网络智能路由架构。控制器通过训练神经网络获取数据流的传输模式,并用训练后的神经网络代替流表,在此基础上提出基于Chebyshev神经网络的智能路由策略,交换机根据数据流的业务类型预测其转发路径,以满足卫星网络应用的服务质量要求。仿真结果表明:所提路由策略显著减少了占用的三态内容寻址存储器存储空间,提高了路由效率。  相似文献   
186.
In this paper we study strategies for better utilizing the network capacity of Internet Service Providers (ISPs) when they are faced with stochastic and dynamic arrivals and departures of customers attempting to log‐on or log‐off, respectively. We propose a method in which, depending on the number of modems available, and the arrival and departure rates of different classes of customers, a decision is made whether to accept or reject a log‐on request. The problem is formulated as a continuous time Markov Decision Process for which optimal policies can be readily derived using techniques such as value iteration. This decision maximizes the discounted value to ISPs while improving service levels for higher class customers. The methodology is similar to yield management techniques successfully used in airlines, hotels, etc. However, there are sufficient differences, such as no predefined time horizon or reservations, that make this model interesting to pursue and challenging. This work was completed in collaboration with one of the largest ISPs in Connecticut. The problem is topical, and approaches such as those proposed here are sought by users. © 2001 John Wiley & Sons, Inc., Naval Research Logistics 48:348–362, 2001  相似文献   
187.
炮管内膛烧蚀磨损现象的分析   总被引:1,自引:0,他引:1  
目前国内外对火炮身管寿命的研究表明,火炮身管疲劳寿命低的问题已基本解决,而烧蚀磨损寿命已成为影响其寿命的主要因素。就此介绍了身管烧蚀磨损的特征和危害,并且分析了造成这些特征和危害的原因,最后就解决这些问题提出了相应的措施。  相似文献   
188.
为提高新一代北斗无线电测定卫星服务在有限带宽内的信息服务容量,借鉴了正交频分复用的理念,新体制无线电测定卫星服务信号设计采用多个子载波进行信号调制。以往针对多用户的分析主要考虑多址干扰,对载波频偏损耗和伪码损耗单独考虑,这不能解释新体制调制在相同的同步头的情况下其他子载波上信号在当前观测子载波上形成较大相关峰的问题,该问题对信号接收产生较大干扰。本文对该问题产生机理进行了分析,并提出了两种相关干扰的消除方法。  相似文献   
189.
In 1968, President Nixon established the Commission on an All-Volunteer Armed Force, or the Gates Commission, which served as the impetus and justification for an All-Volunteer Force (AVF). At the end of its deliberations, the commission recommended abolishing the draft and transforming the U.S. military into a force of volunteers beginning in 1973. Interestingly, the debate regarding the merits of both systems appeared to be largely economic – with cost–benefit analysis playing the primary role. Lately, we are beginning to see a new, politically-motivated impetus for returning to a “system of national service.” The ideas spurring this debate are many: the need to reaffirm the nation state, the commitment of citizens to the state, political ownership and oversight of the forces, the need for social equity in serving the nation, limiting the support for armed conflict by burden-sharing among citizens, and equitably spreading the personal cost of war.  相似文献   
190.
This article develops a mathematical model and heuristic algorithm to design recreational boating mooring fields. The boating industry is important to the Florida economy, and boat storage is becoming a concern among those in the industry. The mooring field design problem is formulated to maximize the total number of boat feet moored in the mooring field. In the model, we allow two adjacent moorings to overlap, which introduces a risk that under certain conditions the boats on these moorings could contact each other. We identify the conditions when contact is possible and quantify the probability of contact. The mooring field design problem is formulated as a nonlinear mixed‐integer programming problem. To solve the problem, we decompose it into two separate models, a mooring radii assignment model and a mooring layout model, which are solved sequentially. The first is solved via exhaustive enumeration and the second via a depth‐first search algorithm. Two actual mooring fields are evaluated, and in both cases our model leads to better layouts than ones experts developed manually. The mooring field design model rationalizes the mooring field design and shows that in one case by increasing the risk from 0 to 1%, the mooring efficiency increases from 74.8% to 96.2%. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009  相似文献   
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