分布仿真系统HLA联邦快速开发包的设计与实现

为提高高层体系结构(HLA)联邦开发的快捷性、易用性、可重用性及节约成本,对其运行支撑环境(RTI)接口进行了封装,结合数据公布订购自定义配置文件和MAP容器,设计并实现了封装的仿真接口包(SPI).首先,给出了SPI包的框架设计、功能分解结构、时序逻辑及函数接口定义,然后设计了仿真应用数据类的具体规范、联邦可执行文件XML和邦元公布订购数据的初始化配置文件,阐述了基于SPI的联邦快速开发步骤,最后用一个简单实例验证SPI.实验表明:相比现有的联邦编程开发软件,SPI简单高效,用户可自行设计并轻松上手,降低了开发成本,满足了特定的仿真需求.     

基于HLA的火控雷达网融合控制系统仿真研究

为提高火控雷达的战场生存能力,研究通过组网技术降低雷达信号截获概率的方法。根据设定作战场景,介绍火控雷达网的工作过程,给出融合控制系统的结构及动态执行过程,设计基于高层体系结构的火控雷达网融合控制系统仿真软件,以此作为平台验证火控雷达组网理论的正确性。最后,通过RTI平台进行仿真实验,结果表明:仿真系统可以有效模拟火控雷达网的数据融合处理和雷达参数控制,组网系统能够延长火控雷达被敌方侦察系统的截获时间。     

基于HLA的地基动能武器作战仿真研究

在分析地基动能武器作战方式的基础上，提出了仿真的基本思路；对仿真中的主动段方案设计、中段飞行和末段飞行3类关键数学模型进行了建模分析；最后基于HLA对地基动能武器仿真系统进行了设计．     

HLA/RTI性能测试与研究

运行支撑环境(RTI)作为应用高层体系结构(HLA)进行分布式仿真的支撑系统,是实现HLA的核心,RTI的质量对HLA系统的运行起着决定性的作用。在介绍HLA体系结构的基础上,阐述RTI测试的内容和指标,通过研究RTI软件的性能测试方法,对MAK RTI1516、MAK RTI1.3和pRTI1516等三个不同版本的RTI软件分别进行性能方面的测试,并对测试结果进行比较分析。     

复杂系统计算机仿真的研究与设计

复杂系统与复杂性是21世纪的核心科学问题之一，并引入国家重点基础研究发展规划。基于复杂系统的复杂性和不确定性，很难想像可以采用传统朴素的还原论法进行可行性研究。推崇多智能主体的模糊计算机仿真来研究复杂系统的复杂性，并设计了一个基于多智能体的复杂系统分布仿真平台。     

一种基于HLA/RTI的卫星组网仿真系统

设计了一种基于HLA/RTI的卫星组网仿真系统,在该系统中卫星节点、星间链路、卫星轨道和通信节点路由被划分为功能独立的联邦成员.这种结构具有良好的可扩展性,可适用于不同的卫星星座结构,同时可以适应不同的路由策略和各类空间通信链路模型.最后通过统计卫星组网网管报文响应时间验证了该仿真系统的可行性.卫星组网仿真系统为卫星组网的其他研究提供了仿真验证平台.     

分布交互仿真及其关键技术

分布交互仿真技术是一门新兴的综合技术，具有广泛的实用价值，本文论述了分布交互仿真的概念，特点和其在武器装备方面的作用以及适合分布交互仿真的ＡＴＭ网络等关键技术。     

分布交互仿真预估算法的数字仿真分析

基于Ｃ＋＋面向对像的编程，设计出分布交互仿真的预估算法分析系统。模拟 对点、多点地多点通信状态下，预估算法的工作过程，对预估算法的效果进行了研究。     

实时分布仿真环境下视景仿真系统的构建

随着仿真技术、计算机技术和网络技术的飞速发展,复杂系统仿真的应用领域不断扩大,对仿真过程的直观性、交互性和逼真度的需求日益提高.实时分布仿真环境下的视景仿真技术是仿真技术研究中的一项关键技术,因此对其进行研究具有重要的意义.对实时分布仿真环境下的视景仿真技术进行研究.分析实时分布仿真环境下视景仿真技术的需求,设计在实时分布仿真环境下视景仿真系统的构建,确定可行的软、硬件开发环境.     

Web服务的核心技术

一般意义上的SOAP是一种用XML封装信息的机制,因此它可以用来实现消息系统.从SOAP、WSDL、UDDI三个方面论述Web服务的核心技术.     

分布式多Agent仿真环境系统体系结构研究

为了提高仿真系统的灵活性和易扩展性,从面向服务的架构(SOA)的角度引入了Agent仿真技术,提出了分布式多Agent仿真系统的控制功能框架,该框架包括仿真运行支撑系统(SRSS)、主代理(MA)、领域代理(DA)及其子域代理(SA)。描述了该实体内Agent的分类和功能,同时,对确保各层次代理之间高效交互的Agent间的通信接口和通信过程进行了描述。最后,给出了一个基于上述框架和方法构建的原型系统。研究表明了代理技术的应用有助于加强分布式仿真系统的规范性,提高其重用性和协同互操作性。     

Numerical simulation of crack extension in aluminium welds

Experimental and numerical investigations on stable crack extension of aluminium-laser beam welds (6XXX-series) are presented. Experiments are carried out on C(T)-specimens. Initial cracks are assumed in the base material and in the fusion zone. Local mechanical quantities are determined by micro-flat tensile specimen, taken from the weld nugget, the heat affected zone and the base material. Finite element calculations together with an evolution strategy are used in order to determine parameters of the Gurson–Tvergaard–Needleman model (GTN-model) used for the simulations. Crack propagation in the base material as well as in the undermatched fusion zone is described in terms of fracture resistance curves. It is found that the GTN-model is able to simulate ductile crack growth in the base material and the fusion zone using non-standard model parameters.     

Efficient distributed simulation through dynamic load balancing

With recent advances in parallel computation, distributed simulation has become a viable way of dealing with time-consuming simulations. For distributed simulations to run efficiently, care must be taken in assigning the tasks (work) in the simulated system to the available physical processors in the computer system. An inefficient assignment can result in excessive communication times between processors and unfavorable load conditions. This leads to long run times, possibly giving performance worse than that with a uniprocessor sequential event-list implementation. This paper establishes the feasibility, and in some cases the necessity, of using dynamic task allocation (rather than a-priori static allocation) in distributed simulation. A dynamic reallocation strategy is developed, and experiments on an iPSC/2 Hypercube indicate that significant improvements in run time can be achieved at low cost.     

Three-dimensional simulation of crack extension in brittle polycrystalline materials

Crack extension resistance in brittle polycrystals was investigated from the viewpoint of three-dimensional microcrack evolution. Even in the case of macroscopically two-dimensional cracks, inhomogeneous distribution of microscopic stress along the crack front gives rise to three-dimensional structures of extended crack surfaces. Numerical simulations of macroscopic crack extension were carried out, which showed that three-dimensional distribution of grain-by-grain thermal stress leads to a significant increase in the crack extension resistance. It was concluded that three-dimensional interpretation on the microscopic inhomogeneity is necessary for the correct comprehension of macroscopic crack extension behavior in brittle polycrystals.     

WEDS: a Web services-based environment for distributed simulation

Web services have the potential to radically enhance the ability of researchers to make use of distributed computing resources, but jargon and a plethora of standards make their use almost impossible for the scientist without prior experience of the necessary technologies. A powerful and simple WSRF-based middleware scheme is presented, designed to let scientists remotely deploy single or multiple instances of a pre-existing code across multiple resources, and giving steering, visualization and workflow functionality with only simple modifications to program code. It is hoped that the development and implementation of such a toolkit will be relevant not only to the problem of deploying workstation-class codes in real time, but also the move towards more tractable alternatives to the Globus toolkit for deployment of processes in a high-performance computing environment.     

A novel special distributed method for dynamic refrigeration system simulation

A novel dynamic mathematical model based on spatially distributed approach has been developed and validated in this paper. This model gives good agreement in predicting the system COP and other parameters. The validated model has been used to enhance the prediction of the micro variations of superheat and sub-cooling. The novel spatial distributed model for the condenser and evaporator in refrigeration system, calculates the two-phase region in gas and liquid field separately since the gas and liquid in the two-phase region have different velocities. Previous researchers have used a pre-defined function of the void fraction in their spatially distributed model, based on experimental results. This approach results in the separate solution of the mass and energy equations, and less calculation is required. However, it is recognized that the mass and energy equations should be coupled during solving for more accurate solution. Based on the energy and mass balance, the spatial distribution model constructed here solves the velocity, pressure, refrigerant temperature, and wall temperature functions in heat exchangers simultaneously. A novel iteration method is developed and reduces the intensive calculations required. Furthermore, the condenser and evaporator models have shown a parametric distribution along the heat exchanger surface, therefore, the spatial distribution parameters in the two heat exchangers can be visualised numerically with a two-phase moving interface clearly shown.