基于.NET平台和Web服务的工作流平台设计与实现     

李则鸣 《教育技术导刊》2010,9(4):123-125

作为实现企业业务过程建模、管理与集成的核心技术,工作流技术不仅可以实现业务与运营流程的弹性转变,而且可以成为多种业务的整合桥梁。以一个大型集团公司的信息化现状为背景,分析工作流平台的业务背景和需求,提出了基于Web服务技术的分布式工作流平台的概念和解决方案。并结合实际的业务需求设计了该平台的数据模型、控制模型和服务接口,阐述了实现过程中的关键问题及解决办法。  相似文献   

云计算研究和发展综述     

袁喆  米欧 《教育技术导刊》2010,(3)

云计算是在分布式处理、并行处理和网格计算的基础上发展的一种新型计算模型,它使计算分布在大量的分布式计算机上,而非本地计算机或远程服务器中,提供了可靠安全的数据存储、方便快捷的互联网服务和强大高效的计算能力。对世界各地区高校在云计算领域上的研究及发展动向进行了论述。  相似文献   

中国各地区R&D经费资源分布差异及变动趋势分析     

韩旺  罗亚非  张赤东 《中国科技论坛》2012,(6):109-114

R&D经费是保证R&D活动的必要资源之一.本文应用熵值法,选取时间跨度在10年以上的最新经济数据,经过可比化处理,对我国不同区域的R&D经费及R&D经费强度进行分析,以探讨我国不同区域R&D经费资源分布及变化趋势.  相似文献   

Two-stage statistical language models for text database selection   总被引：2，自引：0，他引：2  

Hui Yang  Minjie Zhang 《Information Retrieval》2006,9(1):5-31

As the number and diversity of distributed Web databases on the Internet exponentially increase, it is difficult for user to know which databases are appropriate to search. Given database language models that describe the content of each database, database selection services can provide assistance in locating databases relevant to the information needs of users. In this paper, we propose a database selection approach based on statistical language modeling. The basic idea behind the approach is that, for databases that are categorized into a topic hierarchy, individual language models are estimated at different search stages, and then the databases are ranked by the similarity to the query according to the estimated language model. Two-stage smoothed language models are presented to circumvent inaccuracy due to word sparseness. Experimental results demonstrate that such a language modeling approach is competitive with current state-of-the-art database selection approaches.  相似文献   

A pipelined architecture for distributed text query evaluation   总被引：1，自引：0，他引：1  

Alistair Moffat  William Webber  Justin Zobel  Ricardo Baeza-Yates 《Information Retrieval》2007,10(3):205-231

Two principal query-evaluation methodologies have been described for cluster-based implementation of distributed information retrieval systems: document partitioning and term partitioning. In a document-partitioned system, each of the processors hosts a subset of the documents in the collection, and executes every query against its local sub-collection. In a term-partitioned system, each of the processors hosts a subset of the inverted lists that make up the index of the collection, and serves them to a central machine as they are required for query evaluation. In this paper we introduce a pipelined query-evaluation methodology, based on a term-partitioned index, in which partially evaluated queries are passed amongst the set of processors that host the query terms. This arrangement retains the disk read benefits of term partitioning, but more effectively shares the computational load. We compare the three methodologies experimentally, and show that term distribution is inefficient and scales poorly. The new pipelined approach offers efficient memory utilization and efficient use of disk accesses, but suffers from problems with load balancing between nodes. Until these problems are resolved, document partitioning remains the preferred method. Alistair Moffat was supported by the Australian Research Council, the ARC Special Research Center for Perceptive and Intelligent Machines in Complex Environments, and the NICTA Victoria Laboratory. William Webber and Justin Zobel were supported by the Australian Research Council. Ricardo Baeza-Yates was supported by Grant P01-029-F from Millennium Initiative of Mideplan, Chile; and by the University of Melbourne as a visiting scholar at the time this project was undertaken.  相似文献   

数字图书馆网络服务的监测   总被引：2，自引：0，他引：2  

庄纪林 《大学图书馆学报》2008,26(3):38-42,45

数字图书馆通常是一个分布式的松散耦合的多系统构成的庞大的应用服务体系,采用"安装代理"和"远程登录"的商业化网络服务监测软件并不适用于数字图书馆网络服务的监测。在分析数字图书馆网络服务特点的基础上提出了"基于内容"的数字图书馆网络服务监测方案,解决了数字图书馆网络服务体系中只有"访问权限"而没有"管理权限"的网络服务的监测问题。  相似文献   

构建基于J2EE规范的数字图书馆模型的探讨   总被引：2，自引：0，他引：2  

董慧  雷瑛  陈琮  杨宁 《中国图书馆学报》2004,30(3)

从软件工程的角度分析,数字图书馆实质是一个分布式管理信息系统。构建数字图书馆,就是构建一个分布式管理信息系统。J2EE的多层次的分布式应用模型和一系列开发技术规范,为构建数字图书馆平台提供了可靠保证。图1。参考文献11。  相似文献   

软件开发前期模块的并行性分析     

彭正文 《江西教育学院学报》2001,22(6):56-58

首先阐述了在并行分布环境下作业的并行分布策略，并从系统的角度分析了作业的并行性，从软件工程的角度上就软件模块化设计提出一种定量分析模块并行度的方法，该方法对软件中各模块的并行度进行了量化，其值对于软件设计中模块方案的选取有一定的参考价值。  相似文献   

Exploring Dialectical Tensions of Leading Volunteers in Two Community Choirs     

Cameron W. Piercy  Michael W. Kramer 《Communication Studies》2017,68(2):208-226

Leaders of volunteers face different challenges than leaders of paid employees due to different motivations and reward expectations. After synthesizing previous research applying dialectical theory to group members or leaders, this study examines the dialectical tensions that leaders of volunteers experienced and the communication they used to manage those tensions as reported by both the leaders and the volunteers. A constant-comparison method was used to analyze observations and interviews of members and leaders of two community choirs. The findings suggest that leaders of volunteers face eight dialectical tensions representing three broad categories: (a) task and relationship; (b) process and outcome; and (c) internal and external. Leaders negotiated these dialectical tensions through communication strategies including use of humor and appeals to artistic spirituality. These strategies represent hybridization and dualistic discourse rather than a monologic emphasis of one course of action over another.  相似文献   

Educational leadership,management and administration in Africa: an analysis of contemporary literature     

Gladys Nyanchama Asuga  Jill Scevak  Scott Eacott 《School Leadership & Management》2016,36(4):381-400

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