【作者】 田翠华；

【导师】 常桂然；

【作者基本信息】 东北大学 ， 计算机系统结构， 2008， 博士

【摘要】 网格自从90年代中期被提出以来,得到了迅速的发展,被称为是“因特网的第三次革命”。网格是一种基础设施,具有分布性、动态性、异构性、协作性以及服务质量高要求性等特点,目的是进行资源整合与协同解决问题。计算网格在科学和工程计算方面取得了巨大的成就。随着网格技术的不断发展与成熟,网格已经在许多不同的领域得到广泛应用。由于现代交通的迅速发展,将网格技术应用于交通管理决策支持是近年来的一个研究热点。针对城市和公路交通管理决策支持中存在的问题,建设交通信息服务网格(TISG)可以提供一种有效的解决方法。TISG目的是将分布于不同地域的各种异构交通资源通过高速互连网络连接起来进行统一管理,实现资源的全面共享与协同工作,建立对交通参与者透明的高性能交通服务平台,消除交通信息孤岛,改善交通环境,提高城市的交通容量,以满足多层次、全方位的交通需求。在充分地分析相关需求并借鉴大量相关材料的基础上,本文主要研究TISG的体系结构、总体设计、关键技术以及基于网格的交通流模拟实验问题。TISG的体系结构建立在OGSA基础之上,采用层次结构,并遵循OGSA的最新核心规范WSRF,使得TISG的体系结构一开始就定位于开放的、国际标准化的基础之上。在Red Had Linux操作系统与Globus Toolkit 4.0网格平台基础上,讨论了借助PostgreSQL、PBS、MPICH-G2、Java CoG Kits等开发工具实现TISG的方案,给出了TISG的分层结构和系统设计。在TISG的关键技术部分,研究了异构数据库的整合、信息集成、服务的组合与封装、可扩展的网格门户。车道交通流量模拟是交通管理决策支持的一个重要内容。在TISG环境下,对单车道交通流量模拟问题进行了研究。交通路网是一个复杂的庞大系统,在单车道交通流量的模拟研究中,对道路与环境的处理引入了地理元胞自动机理论。为实现人与交通工具相结合体的智能行为,引入了智能体概念。在网格环境下,建立了一个多智能体系统,以进行单车道交通流模拟实验研究。利用网格开发工具GT4中间件,在Eclipse环境下完成实现了模拟实验系统。结果表明,在TISG环境下可以高效地进行交通流模拟实验。本文对交通信息服务网格建设中的部分问题和交通流模拟进行了研究,通过交通流模拟实验,验证了所提方案的可行性、实用性、高效性。本文对网格技术在交通管理决策支持中的应用进行了有益的尝试,但还需要继续完善、改进。更多还原

【Abstract】 The grid technology has been developed rapidly since it was proposed in the mid-1990s, which is regarded as the third revolution of the Internet. A grid is a kind of infrastructures and has many characteristics including distributivity, dynamicality, heterogeneity, cooperativity, and high QoS. The goal of the grid is to integrate resources and to solve a problem cooperatively. Computing grids have achieved great successes in scientific and engineering computing. With the continuous development and maturing of grid technology, grids have been widely applied to many different fields. Due to the rapid development of modern highway and municipal transportation systems, research on applying grid technology to traffic management decision-making support has become a hot spot.For the problems in highway and urban traffic management decision support systems, the building of a traffic information service Grid (TISG) can provide an effective solution. The aim of TISG is to connect a large-scale geographically distributed traffic hardware and software infrastructure together by high speed Internet, manage them integratedly, implement resources sharing and cooperative working, and form a high performance traffic service platform that is transparent to traffic participants. TISG can help eliminate traffic information islands, improve the traffic environment, and increase the capacity of urban traffic, to satisfy multi-faceted and multi-level traffic requirements.Based on thorough analysis on the requirements and survey of a large number of related references, this dissertation focuses on the investigation of the TISG architecture, the system design of TISG, key technologies, and traffic flow simulations.The architecture of TISG is based on OGSA, adopts hierarchical structure, and follows WSRF——the new kernel specifications, which makes TISG positioned at the open and international standardization OGSA at the beginning. Based on the Red Had Linux operating system and Globus Toolkit 4.0 grid platform, the strategy is discussed for the implementation of TISG by using the development tools such as PostgreSQL, PBS, MPICH-G2, and Java CoG Kits, and the hierarchical structure of TISG and the system design of TISG are provided.There are some key technologies researched, such as aggregation of heterogeneous databases, information integration, combination and encapsulation of services, and the extended portal. The simulation of the traffic flow in roads is one of the important tasks of traffic management decision-making support. Under TISG environment, the traffic flow simulation method for a single lane is investigated. Because the urban road network is a large-scale and complicated system, the GeoCA theory is adopted to handle the roads and environment in the traffic flow simulation of a single lane and the concept of agent is introduced in order to simulate the genuine behavior of man and vehicle combination.Under the grid environment, a multi-agent system is built for the simulation experiments on the single lane traffic flow. By using the GT4 grid development tools, the simulation experiment system is implemented in Eclipse environment. Simulation experiment results show that the experiment of traffic flow simulation can be accomplished efficiently under TISG.In this dissertation, some problems in the building of a traffic information service grid and the traffic flow simulation are investigated. The simulation experiments on the traffic flow show that the overall design of TISG is feasible, applicable, and high efficient. The dissertation attempts to apply grid technology to traffic management decision support. Valuable results have been achieved, but more efforts are still needed to consummate and improve the current system.更多还原