【作者】 郝宁；

【导师】 余雪丽；

【作者基本信息】 太原理工大学 ， 计算机应用， 2003， 硕士

【摘要】 在设计和实现一个分布式虚拟实验的过程中，涉及到许多相关的技术问题，本文对其中一些分布式处理技术进行了研究，并部分应用于相应的系统中。 由于当前网络状况不是很理想，网络负载过重造成的延时影响实验的效果，成为制约虚拟实验发展的瓶颈。本文采用了两种方法减少网络传输的信息量。第一种是处理事件的空间一致性问题时，将虚拟实体的行为分为确定行为和不确定行为，其中确定行为只需要在网络上传输行为的触发条件以及相应的行为函数，具体的行为过程由各个客户端在本地进行处理。文中给出了该方法的相应算法。第二种是利用群组通信进行信息过滤，各个用户可以根据自己的不同需求选择需要或者不需要哪些信息，对于不需要的信息就可以过滤掉。第一种方法已应用于简单的系统中，收到良好的效果。 对于分布式系统中事件的时间一致性处理问题，本文介绍了北京航空航天大学研究的一种事件定序算法，并根据分布式虚拟实验的具体情况对其进行了一点改进。 在处理分布式并发控制的问题时，本文在研究具体系统需求的基础上，对多种并发控制方法进行了分析比较，最终采用“悲观加锁法”作为系统实现过程中并发控制的处理方法。在文中介绍了具体实现的原理和过程。 此外，本文还简单介绍了一个具体的分布式虚拟实验的设计和实现过程，包括系统的需求分析、功能设计、结构设计、实现工具的选择以及关键技术实现的相关方法。对于本人在具体系统实现过程中遇到的一口太原理工大学硕士学位论文些问题也在文章中列了出来，并给出了相关的解决方法，希望对遇到相同问题的人有所帮助。更多还原

【Abstract】 Some technologies about distributed system are studied in my paper, and parts of these technologies are applied to the system that I have built.Because the status of web is not very good currently, the time delay that is caused by web transmission hampers the development of distributed virtual experiment. Two methods of reducing the quantity of transmitting information in web are introduced in this paper. Firstly, when we solve the problem about consistency of space, the actions of virtual objects are compartmentalized to certain actions and uncertain actions. When a certain action is disposed, only start signal and the relevant function of the action are transmitted in web, and each client oneself simulates the course of this action locally. The relevant algorithm for this method is listed in this paper. Secondly, I intend to use the method of information filtering that based on multicast. Every client can select the useful information according to his own need, and the useless information will be filtrated. The first method has beenapplied to a simple system and has got a good result.About the question of consistency of time in distributed system, an algorithm that studied by Beijing University of Aeronautics and Astronautics is introduced. I also ameliorate this algorithm on the basis of requirement for distributed virtual experiment.After analysis of many methods for concurrent control and the requirement of my system, I adopt the method of pessimistic lock.In my paper, I also introduce the course of designing and implementing a distributed virtual experiment, including requirement analysis of system, design for function and structure, choice of tools. I list the questions that I have met in the course of achieving the system, and I also give the relevant methods to solve these questions.更多还原