查询词典 distributed database

Several experimental applications have been developed finally. In this paper, there areinnovations from the following four aspects:1. Definition and research methods of current distributed system and distributedinteractive simulation system follow those of traditional parallel computing system.While this paper points out it is one-sided to measure the scalability just from thenumber of processors and performance of a system, because the resources of distributed systems are heterogeneous and they can be used in diverse applications. Inthis paper, scalability of distributed interactive simulation platform is defined as theability of scaling (including scale-up and scale-down) in functionality and performanceof systems which is run on the platform when number of processors and otherhardware resources such as network change, i.e. when problem size is scaled up and system resources is increased, the performanceremains fixed and it is easy to expand the functions of simulationapplications.

本文的创新工作主要体现在下述4个方面：1、现有的分布式系统和分布式交互仿真系统可扩性的定义和研究方法都沿用了传统的并行计算系统可扩性的定义和研究方法，本文指出分布式系统的系统资源异构多样、应用种类丰富多样，只从传统方法采用的处理机资源和性能角度衡量一个系统是否可扩是有一定的片面性，提出了分布式交互仿真平台可扩性的定义是在处理机和网络等系统资源变化时，运行在平台上的分布式交互仿真系统在性能和功能方面发生扩缩的能力，即当问题规模扩大时，增加系统资源，系统能获得指定的性能及在功能方面能方便进行扩充。

Primarily, the thesis assays the condition of network framework, the network was divided into three levels in terms of network management in order to establish the distributed method ,and still pointing out the intention and denotation of studying the Topology Discovery.Next, the thesis analyzes SNMP protocol minutely, including its development, principle, and the Network Management system that established on the SNMP protocol. Have analysed MIB in detail and the application way of MIB in network management .The thesis also assays the ICMP protocol, describing its working principle and the format of datagram minutely , and describing two important tools of ICMP- Ping and TraceRoute in detail. On the base of upper analysis, the thesis expounds a kind of distributed Topology Discovery project, and book it in one autonomy system. Topology Discovery was divided into two levels in terms of network management, and analyses the way of linking up between the two level. The thesis minutely assays Router-Level Topology Discovery technology basing on SNMP and Subnet-Level Topology Discovery technology basing on ARP and ICMP. According to these analyses, the thesis explores the specific methodology and the technology of XML data object which using the WinSNMP API to achieve topology discovering system on the development platform of Visual C++, and also analyses the technology of topology analysis and topology graph minutely. Moreover, the thesis assays the technology of basic firewall and Topology Discovery response strategy. Finally, the thesis analyses the underlying blind problem of the topology finding, and also analyses the reason that the blind problem produced and the way that reduced. The distributed algorithm that this paper puts forward has a certain directive significance in wireless network or other fields.

本文首先分析了网络结构状况，将网络从网络管理的角度划分为三个层次，为分布式的方法奠定了基础，同时还指出拓扑发现研究的目的及意义；接着本文分析了SNMP协议，详细分析了SNMP协议的发展状况，协议的工作原理，以及由SNMP协议基础上建立的SNMP网络管理体系，详细分析了MIB，以及MIB在网络管理上的应用方式；本文又分析了ICMP协议，详细描述了ICMP的工作原理和数据报格式，并详细描述了ICMP的两个重要工具-Ping 和TraceRoute；然后本文在结合上述分析的基础上，提出了一种分布式的拓扑发现方案，将拓扑发现拟订在一个自治系统内，将拓扑发现从网络管理角度划分为路由器级和子网级两个层次，分析了两个层次之间的衔接方式，同时从拓扑地域的角度将拓扑发现过程分布化，分析了分布式算法的具体方法和分布式结点之间的数据通讯方法，本文详细分析了基于SNMP的路由器级拓扑发现技术和基于ARP和ICMP的子网级拓扑发现技术；根据这些分析，本文利用XML数据对象作为分布式算法中的数据对象，分析了XML的技术，本文使用Visual C++开发平台实现网络拓扑发现系统，详细分析了使用WinSNMP API实现基于SNMP的路由器级拓扑发现和基于ARP的子网级拓扑发现，分析了使用Winsock编程实现基于ICMP的子网级拓扑发现，本文还对拓扑分析和拓扑图的绘制技术作了较细致的分析；本文最后还分析了基本防火墙技术，分析了几种类型的防火墙对拓扑发现带来的影响，以及在拓扑发现时的应对策略，本文还分析了拓扑发现中可能产生的盲点问题，分析了盲点产生的原因以及拓扑发现中减少盲点的方法。

With the analysis of the small gas distributed energy-supplying system, the criteria and method to conduct the optimized configuration and evaluation of energy supplying system are studied. And the influence of the factors such as the load calculation for the system design, the selection of the unit groups, and the establishment of the energy-storing facilities etc. on optimized configuration and operation of small gas distributed energy-supplying system is discussed emphatically. The completer benefit evaluation system is formed for the small gas distributed energy-supplying system. The corresponding evaluation software is developed.

通过对采用天然气的小型分布式供能系统的分析，研究了对该供能系统进行优化配置和评估的原则与方法；著重讨论了系统设计负荷的计算、机组的选择、蓄能装置的设置等因素对小型天然气分布式供能系统优化配置与运行的影响，并形成了一套相对完整的、对小型天然气分布式供能系统进行效益评估的体系，进而设计出了相应的评估软件。

T lymphocytes were distributed mainly in the middle and underneath of mucous layer before 4-day-old,but they distributed uniformly in the whole mucous layer after 4-day-old,CD4+ cells concentrated in the interfollicular areas,and both CD3+ and CD8+T lymphocytes distributed in the lamina propria and epithelium.

在定位分布变化上，4日龄之前，T淋巴细胞主要分布在黏膜层的中下部区域，而4日龄以后的各日龄在整个黏膜层中均匀分布，CD4+细胞主要聚集在滤泡间区域，而CD3+细胞和CD8+细胞在固有层中和黏膜上皮中都有大量分布。

Its software development tool are very important to the applications of virtual reality technology because of the rapid development of network technology Being aimed of the shortcoming that the development for the distributed parallelism of simulation computing unit is not enough and formal in current distributed virtual environment systems, we study the modeling language of virtual environment and the system architecture of distributed virtual environment in a new view point, build a complete extensible theory framework novelly for the research of virtual environment technology.

本文针对当前分布式虚拟环境系统对仿真计算单元的分布并行性开发不够充分和规范的缺点，从一个全新的角度来研究虚拟环境的建模语言及其分布式虚拟环境的系统结构，开创性地为虚拟环境技术的研究建立了一个全面可扩展的理论框架。

It is found that the distributed microscopic traffic network simulation methods based on distributed systems require not only the careful discussions on traditional traffic flow theory, such as the driver's uncertain behaviors in selecting the route and changing lane, but also some deep researches on parallel techniques. These key techniques about how to realize parallel and distributed simulations include how to partition the large-scale road network into sub-areas, how to divide the multi-course in dynamic traffic flow operation, how to finish the informational transmission among processors, and how to realize the clock-synchronization among processors etc..

在基于分布式系统的路网交通流并行微观模拟研究中除了需要对传统的交通流理论如驾驶员路径选择、车道变换等微观不确定性行为进行仔细探讨外，还必须对道路网子网的划分方法，交通流动态运行过程中多个进程的划分方式及各进程之间消息传递、各处理器间的时钟同步方式等实现并行的关键技术问题进行深入研究。

Along with the extensive application of distributed system, distributed database system has become an important field of information processing.

近年来，随着分布式系统的广泛应用，分布式数据库已成为信息处理中的一个重要环节。

The distributed Web technology is a combination of network and database technologies and it is also an application of multilayer distributed application.

分布式Web技术是网络技术和数据库技术的一种结合，也是一种多层分布式应用。

The architecture of Client/Server based on transaction middleware is a typical kind of the distributed On-line Transaction Processing, becoming a major platform of enterprise information system, which offers communication of striding platform, loading balance, fault-tolerant and resumable ability, and strengthens a new generation middleware in common with 3-layer architecture provided with the strong security, excellent management and high availability in common. Numerous distributed system, different database and different network environment are closely linked up among an enterprise, offering the function of mutual operation on application layer.

基于交易中间件的C／S结构是一种典型的分布式事务处理系统，成为构筑企业信息系统的主流平台，它提供了强大的跨平台通讯、负载平衡、容错及其故障恢复能力，并在这个基础上进一步强化了安全性、可管理性和高可用性的新一代通用型三层结构平台的中间件，把企业中众多的异构系统、异构数据库、不同网络环境紧密的联系起来，并在应用层提供了互操作性的功能。

Then, after reviewing former research, we combine the solution of industry and academy, a new architecture called BWADM based on the researches above is proposed, it is a distributed data mining system based on Web services and Agent in Electronic commerce environment. Web service composition rules and execution of Web service composition are discussed. These modules are introduced detailedly in Electronic commerce environment; there are algorithm management module, control center module, algorithm database module and model representation module. Lastly, a prototype system of distributed data mining is given in Electronic commerce.

在此基础上，结合业界和学术界对Web服务和移动Agent的研究成果，将Web服务和Agent最新技术引入了电子商务环境中分布式数据挖掘，提出了电子商务环境下基于Web服务和移动Agent技术的数据挖掘架构BWADM，并论述了组合服务规范与组合服务的执行，具体阐述了此架构的数据预处理组件、算法管理组件、控制中心组件、算法库组件和模型表示组件。

Bob Eckert has been chairman and chief executive of Mattel for eight years.

美泰董事长兼首席执行官鲍勃·埃克尔特在任已8年。

The outlook for honors and disgraces carries on and surpasses the traditional outlook for honors and disgraces theoretically, and carries on and develops the theory of construction of socialist mora...

社会主义荣辱观的提出在理论上是对传统荣辱观的一次继承和超越，是对社会主义道德建设理论的继承和发展，在实践上有利于形成良好的社会风尚。