一种支持并行离散事件仿真建模和并行模型检验的建模语言

并行离散事件仿真(Parallel Discrete Event Simulation,PDES)模型的正确性和可信度对PDES应用的发展起着决定性作用.然而,现有的并行离散事件仿真开发环境都没有提供仿真模型检验功能.并行模型检验(Parallel Model Checking,PMC)方法以其完备性、高效性已经在工业...     

多核环境下负载均衡的并行离散事件全局调度机制

分析了多核环境下传统的离散事件时间弯曲并行系统的性能,针对其事件调度开销小和负载均衡能力强难以兼得的问题,提出了一种基于分布式队列的全局调度机制,设计了相应的数据结构和调度算法,大大减少了锁开销.通过大量实验对多核环境下几种典型离散事件系统并行策略的性能分析表明,本文提出的全局调度策略不仅事件调度开销小,而且回滚率大大降低,有效克服了传统策略回滚量较大或难以实现动态负载平衡的情况,并具备良好的可扩展性.     

用于仿真与模拟离散事件的同步并行环境

美国国防部仿真界正努力推动仿真框架的应用,以达到降低费用、促进各不同学科仿真的可伸缩性、可移植性、互操作性的目的。为支持“学科交叉”(interdisciplinary)方法,仿真框架必须提供的服务应有:高级时间管理、数据时间标记、可重复时间/事件同步、共享存储体系通信、仿真期间动态地加减模型等。支持这些仿真服务的方法必须用一个支持高性能计算(HPC)的现存框架来集成仿真体系。本文介绍的一种方法是将SPEEDES(SynchronousParallelEnvironmentforEmulationandDiscreteEventSimulation),即“用于仿真与模拟离散事件的同步并行环境”的建模框架融入JMASS体系。这一基本方法就是以SPEEDES分布式仿真管理服务(DSMS)和SPEEDES建模框架(SMF)为基础,将SPEEDES仿真引擎与JMASS结合,为JMASS应用程序接口(API)建立一个接口库。使用SPEEDES后,要求支持复杂仿真的HPC服务将会顺理成章。另外,有些特性,诸如代码生成、模型互操作性、支持多种建模等也将得以实现。最后集成的框架将允许JMASS仿真在各种并行和分布式高性能计算机(包含MPP)及计算环境中执行。由此,现行JMASS系统的可移植性和可伸缩性得以扩展。     

HLA/RTI中的DDM概念与相关服务的关系

本文介绍了IEEE1516标准中的数据分发管理下的最新概念和相关服务,包括维、区间、区域规范、区域实现、缺省区域,以及它们之间的相互关系。同时介绍了在实现DDM服务时,需要考虑和对象管理、声明管理之间的相互关系。     

基于离散事件仿真要素的军事仿真因果追溯方法

基于离散事件系统建模与仿真的军事仿真系统在军事筹划阶段扮演着至关重要的作用。因果追溯与分析是军事仿真中重要的技术,它可以在大量的数据与复杂的交互关系中找出时序上的关联关系,帮助研究人员确定作战行动中的一些关键实体或事件,用于探究战争的发展脉络与蕴含其中的因果关系。首先对作战仿真领域的因果追溯分析做了简要介绍,然后提出了一种基于离散事件仿真要素的因果追溯分析方法,这种方法可以分析军事仿真中的因果关系,并且有很高的通用性和良好的实用性。     

C3I系统效能仿真方法及环境研究

采用面向对象的方法和离散事件仿真技术,探讨了C3I系统效能仿真方法,并介绍了C3I系统效能仿真环境的设计思想。该环境能够支持多种模型的集成仿真,并易于扩展和扩充。     

地空导弹兵混编群作战仿真研究

应用离散事件动态系统仿真的基本理论,建立了地空导弹兵混编群作战过程仿真模型,并用Arena仿真平台实现了仿真。通过仿真实例,分析了不同空袭目标流密度和空袭目标采取低空突防时对目标突防概率的影响。仿真结果表明,在该实例中,增大空袭目标流密度对目标突防概率没有显著的影响,而采取低空突防对目标突防概率影响显著。最后,对仿真结果进行了分析,证明了仿真模型的有效性。     

一种面向大规模HLA仿真的并行区域匹配算法

HLA仿真中,数据分发管理实现基于值的过滤,可以有效减少盟员接收冗余数据的可能性和网络中的数据流量。大规模HLA仿真系统在仿真推进中需要大量的区域匹配计算以维护数据分发管理的正确性。现有的区域匹配算法大多需要对所有区域进行匹配计算,造成了大量计算资源的浪费;同时,主要基于串行匹配思想,难以充分发挥多核平台的并行计算优势。针对现有区域匹配算法的局限性,提出了一种面向大规模HLA仿真的并行区域匹配算法,该算法能够实现对一次仿真推进中多个改变区域的并行匹配计算,同时在匹配计算中采用基于移动相交的基本思想,利用区域范围移动前后的历史信息,将匹配限定在移动区间之内,减少了大量的无关计算。理论分析与实验结果表明该算法尤其适合基于多核计算平台构建大规模分布式仿真的应用需求。     

炮兵对有生力量压制比的仿真计算方法

为了评估炮兵对有生力量压制效果,应用离散事件仿真方法建立了炮兵射击有生力量仿真模型,提出一种炮兵对有生力量压制比的仿真计算方法。首先,给出了压制比的概念与模型。然后,建立了基于离散事件仿真的炮兵射击有生力量模型。最后,结合实例验证了仿真计算方法的正确性。     

陆军作战仿真模型标准化研究

模型标准化是规范仿真模型开发,避免低水平重复建设的重要环节。在对陆军作战仿真模型体系进行分析和归纳的基础上,对仿真模型架构、模型构建、模型管理以及模型交互进行了标准化设计,提出了基于插件机制的“柔性”仿真模型架构、仿真实体组件化建模机制、采用“方案－单元－实体－组件”方式的仿真实体管理机制以及采用消息驱动、事件订购和分发方式的模型交互机制。     

论管理协议细栈MTS的构造

开放系统互连管理 OSIM 是 OSI 参考模型中定义的特定应用服务元素 SASE 之一,也是唯一涉及全部七层协议的服务元素。OSIM 在控制和协调 Multivendor 和 Multidomain系统中所起的作用已使它成为改进网络性能和服务水平的关键性因素。并非所有开放系统均能提供全七层支持,因此,本文提出一种管理协议细栈 MTS(Management Thin Stack)结构,讨论了它自身的构造性特及其在上述管理环境下的作用。     

Value management of diagnostic equipment with cancelation,no‐show,and emergency patients

Magnetic resonance imaging and other multifunctional diagnostic facilities, which are considered as scarce resources of hospitals, typically provide services to patients with different medical needs. This article examines the admission policies during the appointment management of such facilities. We consider two categories of patients: regular patients who are scheduled in advance through an appointment system and emergency patients with randomly generated demands during the workday that must be served as soon as possible. According to the actual medical needs of patients, regular patients are segmented into multiple classes with different cancelation rates, no‐show probabilities, unit value contributions, and average service times. Management makes admission decisions on whether or not to accept a service request from a regular patient during the booking horizon to improve the overall value that could be generated during the workday. The decisions should be made by considering the cancelation and no‐show behavior of booked patients as well as the emergency patients that would have to be served because any overtime service would lead to higher costs. We studied the optimal admission decision using a continuous‐time discrete‐state dynamic programming model. Identifying an optimal policy for this discrete model is analytically intractable and numerically inefficient because the state is multidimensional and infinite. We propose to study a deterministic counterpart of the problem (i.e., the fluid control problem) and to develop a time‐based fluid policy that is shown to be asymptotically optimal for large‐scale problems. Furthermore, we propose to adopt a mixed fluid policy that is developed based on the information obtained from the fluid control problem. Numerical experiments demonstrate that this improved policy works effectively for small‐scale problems. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 287–304, 2016     

时间管理在实时仿真中的改进

时问是分布仿真中的核心概念;时间管理是分布交互仿真的关键技术.探讨了分布交互仿真中高层体系结构(HLA)的时间管理机制,针对HLA在实时系统仿真方面的不足,分析其原因,提出了时间管理在实时仿真中的改进方法,对HLA在实时系统仿真中的应用有一定的参考价值.     

On queueing systems with variable service capacities

In some queueing systems the total service capacity utilized at any given time is a variable under the control of a decision maker. Management doctrines are examined which prescribe the actual service capacity as a function of the queue length and the recent history of the system. Steady state probabilities, expected queue lengths and frequencies of change in capacity are evaluated for a wide class of possible control schemes. Optimization procedures are outlined.     

信息融合系统中算法管理理论研究

信息融合系统中,数据源千差万别,多种多样;而众多的信息融合算法也具有不同的适应性.通过对实验数据的分析说明了数据源以及融合算法的选择显著影响了最终的融合结果.针对数据源、融合算法和融合结果之间的关系,以优化融合结果为目的,提出了信息融合系统中算法管理(Algorithm Management)的理论,阐述了算法管理的目标、算法管理可能的方法和算法管理的实现结构.最后讨论了信息融合领域中与算法管理理论相关的其他问题.     

Optimal material control in an assembly system with component commonality

Allocation of scarce common components to finished product orders is central to the performance of assembly systems. Analysis of these systems is complex, however, when the product master schedule is subject to uncertainty. In this paper, we analyze the cost—service performance of a component inventory system with correlated finished product demands, where component allocation is based on a fair shares method. Such issuing policies are used commonly in practice. We quantify the impact of component stocking policies on finished product delays due to component shortages and on product order completion rates. These results are used to determine optimal base stock levels for components, subject to constraints on finished product service (order completion rates). Our methodology can help managers of assembly systems to (1) understand the impact of their inventory management decisions on customer service, (2) achieve cost reductions by optimizing their inventory investments, and (3) evaluate supplier performance and negotiate contracts by quantifying the effect of delivery lead times on costs and customer service. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48:409–429, 2001     

An application of yield management for Internet Service Providers

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     

武警院校军事学研究生教学管理与保障存在问题及对策

武警院校军事学研究生教学管理与保障存在着课程体系不够科学、教学运行管理不严密、教学保障不到位及教学质量评价体系不完善等问题。应采取有效措施修订现行课程体系,建立和完善研究生教学质量评价体系,改善教学条件,形成教学管理合力育才的良好机制。