基于XML的CAD产品信息集成技术研究和实现

异构数据源的交换和共享是虚拟产品开发中信息集成的核心。采取基于XML的方式进行CAD产品信息集成,具有结构清晰和互操作性强的优点。该文针对汽车模具产品开发的应用背景,实现了基于XML的CAD产品信息数据共享,为汽车模具虚拟产品开发系统中的其他分系统提供了快速有效的产品信息访问。     

基于虚拟数据库的信息系统集成研究

随着计算机技术的迅速发展,信息资源的异构性在各行各业的信息管理系统中无处不在,形成了大量的信息孤岛,这使得如何在复杂的应用系统中实现异构系统之间的互联、互访和数据共享成为一个重要的研究方向.针对当前各类信息系统之间缺乏有效的信息整合平台,信息集成度差的现状,提出采用虚拟数据库的信息集成方法为不同自治、异构、分布的数据提供一个统一的全局虚拟数据视图来实现各信息系统之间的透明访问.并结合电力系统的特点,使用数据仓库和虚拟数据库相结合的方法,提高了异构数据查询的效率.     

基于云存储的农业虚拟服务平台架构

提出了一种基于云存储模型的农业虚拟服务平台架构,用于整合各种农业信息资源,提供统一的海量农业信息存储、高性能计算、软件和数据共享服务。分析、设计了资源申请解析和虚拟资源预留分配两个核心模块,提出了一种树型虚拟资源分配策略算法。给出了原型系统的部署方案。通过实验证明了该体系架构的可行性。     

某型导弹的虚拟维修系统中信息模型的实现

本文从虚拟维修中装配拆卸模型的基本特点入手,给出了在进行虚拟维修中所需要的模型的层次化组织结构。结合层次结构的特点和所需要的信息给出了建立层次信息模型的方法。并应用于某型导弹的战斗部的模型建立。     

动态安全的虚拟组织体系结构

虚拟组织作为网络经济时代组织创新的新模式,在虚拟组织共享组织信息的框架下保障组织信息的动态安全成为组织者不得不考虑的问题。从计算机及网络科学的角度,探讨了一种动态安全的虚拟组织体系结构。在该体系结构呈现的虚拟组织平台系统上能够动态地构建多个具有保护组织信息访问安全、存储安全和流转安全的虚拟组织系统,从技术层面有效保护虚拟组织电子信息资产的安全。     

地震网络中数据共享平台的研究与设计

随着Internet中数据信息量迅速增加,专业领域内的数据共享逐渐成为一个重要研究领域,该文首先对地震网络数据分布的特殊性进行了概括,分析国外典型数据共享项目OGSA-DAI的特点,针对其存在以Web Service作为接口而不便于应用开发等不足,提出建立面向应用的地震网络数据共享平台的需求和目标,文中阐述了共享平台的架构设计和主要模块的功能.对该平台实现的关键技术虚拟目录的建立和虚拟中心数据库做了详细介绍.     

基于PDM的虚拟维修性分析评价系统与数据管理

针对虚拟维修性分析评价系统（VMSAS）使用过程中的数据共享与获取管理、一致性控制、安全性管理等问题，提出了基于产品数据管理（Product Data Management, PDM）系统的系统集成与数据管理方案，并选择TeamCenter系统进行了数据及技术信息的合理分类、组织、存储与管理等方案的实现。设计了VMSAS与PDM解决方案TeamCenter的系统集成方案，并对接口系统的设计实现和关键技术进行了讨论。     

区域地理空间数据共享平台与目录服务研究

分布式、异构的地理空间数据的整合与共享是空间信息网络服务的关键技术。构建了基于SOA和XML Web Services技术的地理空间数据共享平台和目录服务体系,提出了建设区域地理空间数据共享服务平台的技术流程。研究的共享体系和目录服务体系能够有效地解决地理空间数据共享中信息组织、检索、定位、透明访问和集成应用的关键问题。     

基于元数据的国土资源共享模型研究与设计

国土资源数据是国家资源和空间地理基础信息资源的重要组成部分,具有数据复杂、存储格式多样、分布广泛等特点。传统的共享模式对数据类型复杂、异地、异构的数据共享存在困难。而基于元数据的数据共享方法为国土资源部门解决数据共享、信息服务社会化提供了重要途径。以空间元数据为核心,采用XML描述元数据标准和Web服务的架构模式,设计了一个面向国土资源的空间信息资源共享模型。     

数据共享环境下统一信息标准的建设与应用

数据共享可以解决应用系统互联互通的问题,共享数据中心的建设是实施数据共享的有效方案.共享数据中心是数据交换的中继链,也是综合信息的集市,实施的关键在于共享主题库的分类组织与上下行数据的准确转换,因此数据共享环境下统一信息标准的建设尤其重要.分析了实现信息标准的意义与作用,基于高等教育管理信息标准并结合实际探讨了信息标准体系的建设过程,将其应用于共享主题数据库的建设和数据中心的数据桥接与交换当中,具有很强的实用价值.     

基于粗糙集和灰色的供应链知识共享风险预警

从分析供应链的重要组织形式—虚拟企业的知识共享风险预警的评价标准入手,提出具有层次结构的风险预警评价属性模型。然后,利用粗糙集和灰色的基本理论和方法,建立基于粗糙集和灰色理论的供应链知识共享风险预警模型框架结构图,并给出其中的基于分辨矩阵的指标属性约简算法,优化评价指标。在此基础上,使用灰色理论对知识共享的风险进行评估。最后通过实例说明该预警模型的有效性及实用性。     

网格：面向虚拟组织的资源共享技术

1.引言在过去的几年里,“网格”(Grid)一词主要在学术界使用。如今,它已从幕后走到了前台,在IT界引起人们的普遍关注。术语网格源于学术界的学派描述共享联网的所有资源(从PC到超级计算机),以共同地解决超级计算任务。一般认为,有关网格的实质性研究始于1995年。当时美国Argonne国家实验室的Ian Foster博士和南加洲大学信息科学研究所的Carl Kesselman博士共同领导了美国政府(能源部、NASA等)支持的高性能分布式计算项目Globus。在此项目中,为了标     

基于虚拟组织的网格文件资源共享模型

网格计算主要关注大规模的资源共享,且这种共享是高度可控的。为解决网格环境下文件资源共享与管理的问题,提出了一个网格文件资源共享模型FsvGrid。该模型引入注册通知机制,并采用确定性算法与非确定性算法相结合的消息传递机制,使得网格中的各个节点之间能够高效协作;采用分层结构,屏蔽了文件资源的多样性;增加了共享的安全性,可以对共享进行控制;提出了一种依靠虚拟组织来对文件资源进行管理的方式,解决分布式资源难以管理的问题。     

高安全度虚拟组织中动态防火墙的设计和实现

网格计算的本质含义是在动态变化的、拥有多个部门或者团体的复杂虚拟组织内,灵活安全地协同实现资源共享和问题求解[1]。建立安全、稳定、可扩充的虚拟组织是整个网格技术的基础。本文分析了在网格环境下组建高安全度虚拟组织时传统防火墙体制遇到的问题,设计了旨在保障虚拟组织高度安全性的新型动态防火墙模型,并给出了在Linux平台下这种防火墙的实现方法。     

Knowledge sharing and creation in a teachers’ professional virtual community

By virtue of the non-profit nature of school education, a professional virtual community composed of teachers provides precious data to understand the processes of knowledge sharing and creation. Guided by grounded theory, the authors conducted a three-phased study on a teachers’ virtual community in order to understand the knowledge flows among community members from different organizations. This study also portrays the process of knowledge sharing and creation for teachers participating in virtual teams of a teachers’ professional community. The resulting model articulates causal conditions, action/interaction strategies, consequence, and contextual environments. The concept of knowledge buckle is derived to connect the knowledge transfer among socialization, externalization, and combination activities.     

Fostering the determinants of knowledge sharing in professional virtual communities

Professional virtual communities (PVCs), which are formed on the Internet, are expected to serve the needs of members for communication, information, and knowledge sharing. The executives of organizations should consider PVCs as a new innovation or knowledge pool since members share knowledge. However, many PVCs have failed due to members’ low willingness to share knowledge with other members. Thus, there is a need to understand and foster the determinants of members’ knowledge sharing behavior in PVCs. This study develops an integrated model designed to investigate and explain the relationships between contextual factors, personal perceptions of knowledge sharing, knowledge sharing behavior, and community loyalty. Empirical data was collected from three PVCs and tested using structural equation modeling (SEM) to verify the fit of the hypothetical model. The results show that trust significantly influences knowledge sharing self-efficacy, perceived relative advantage and perceived compatibility, which in turn positively affect knowledge sharing behavior. Furthermore, the study finds that the norm of reciprocity does not significantly affect knowledge sharing behavior. The results of the study can be used to identify the motivation underlying individuals’ knowledge sharing behavior in PVCs. By investigating the impacts of contextual factors and personal perceptions on knowledge sharing behavior, the integrated model better explains behavior than other proposed models. This study might help executives of virtual communities and organizations to manage and promote these determinants of knowledge sharing to stimulate members’ willingness to share knowledge and enhance their virtual community loyalty. As only little empirical research has been conducted on the impact of knowledge sharing self-efficacy, perceived relative advantage, and perceived compatibility on the individual’s knowledge sharing behavior in PVCs, the empirical evidence reported here makes a valuable contribution in this highly important area.     

Automatically composed workflows for grid environments

Once the realm of high-performance computing for scientific applications, grid computing is rising as a key enabling infrastructure for resource sharing and coordinated problem solving in dynamic multiinstitutional virtual organizations. Grids build over networking technology to provide middleware support such as locating files over a network of computers, scheduling the distributed execution of jobs, and managing resource sharing and access policies.2 The need of scientific communities to interconnect applications, data, expertise, and computing resources is shared by other application areas, such as business, government, medical care, and education.     

A secure collaboration service for dynamic virtual organizations

Nowadays, various promising paradigms of distributed computing over the Internet, such as Grids, P2P and Clouds, have emerged for resource sharing and collaboration. To enable resources sharing and collaboration across different domains in an open computing environment, virtual organizations (VOs) often need to be established dynamically. However, the dynamic and autonomous characteristics of participating domains pose great challenges to the security of virtual organizations. In this paper, we propose a secure collaboration service, called PEACE-VO, for dynamic virtual organizations management. The federation approach based on role mapping has extensively been used to build virtual organizations over multiple domains. However, there is a serious issue of potential policy conflicts with this approach, which brings a security threat to the participating domains. To address this issue, we first depict concepts of implicit conflicts and explicit conflicts that may exist in virtual organization collaboration policies. Then, we propose a fully distributed algorithm to detect potential policy conflicts. With this algorithm participating domains do not have to disclose their full local privacy policies, and is able to withhold malicious internal attacks. Finally, we present the system architecture of PEACE-VO and design two protocols for VO management and authorization. PEACE-VO services and protocols have successfully been implemented in the CROWN test bed. Comprehensive experimental study demonstrates that our approach is scalable and efficient.     

A national-scale authentication infrastructure

Participants in virtual organizations commonly need to share resources such as data archives, computer cycles, and networks, resources usually available only with restrictions based on the requested resource's nature and the user's identity. Thus, any sharing mechanism must have the ability to authenticate the user's identity and determine whether the user is authorized to request the resource. Virtual organizations tend to be fluid, however, so authentication mechanisms must be flexible and lightweight, allowing administrators to quickly establish and change resource-sharing arrangements. Nevertheless, because virtual organizations complement rather than replace existing institutions, sharing mechanisms cannot change local policies and must allow individual institutions to maintain control over their own resources. Our group has created and deployed an authentication and authorization infrastructure that meets these requirements: the Grid Security Infrastructure (I. Foster et al., 1998). GSI offers secure single sign-ons and preserves site control over access policies and local security. It provides its own versions of common applications, such as FTP and remote login, and a programming interface for creating secure applications. Dozens of supercomputers and storage systems already use GSI, a level of acceptance reached by few other security infrastructures.     

Working Together Apart? Building a Knowledge‐Sharing Culture for Global Virtual Teams

A new impetus for greater knowledge‐sharing among team members needs to be emphasized due to the emergence of a significant new form of working known as ‘global virtual teams’. As information and communication technologies permeate every aspect of organizational life and impact the way teams communicate, work and structure relationships, global virtual teams require innovative communication and learning capabilities for different team members to effectively work together across cultural, organizational and geographical boundaries. Whereas information technology‐facilitated communication processes rely on technologically advanced systems to succeed, the ability to create a knowledge‐sharing culture within a global virtual team rests on the existence (and maintenance) of intra‐team respect, mutual trust, reciprocity and positive individual and group relationships. Thus, some of the inherent questions we address in our paper are: (1) what are the cross‐cultural challenges faced by global virtual teams?; (2) how do organizations develop a knowledge sharing culture to promote effective organizational learning among culturally‐diverse team members? and; (3) what are some of the practices that can help maximize the performance of global virtual teams? We conclude by examining ways that global virtual teams can be more effectively managed in order to reach their potential in this new interconnected world and put forward suggestions for further research.