【作者】 高曙；

【导师】 陈定方；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2007， 博士

【摘要】 随着可视化技术在医学、地质、海洋、气象、航空和商业事物处理等领域日益广泛的应用,以及网络技术的发展,那些需要可视化的数据变得数量更大,更具分布性、自治性、异构性和动态性。面对日益膨胀的数据和高度复杂的计算模型,传统方式下使用本地资源或单个资源进行可视化的模式已经不能满足需要,必须利用分布式技术、并行技术将其过渡到新的处理模式上。网格和Web服务技术的出现,为可视化应用方式的改变带来了契机,因为网格就是要把整个Internet整合成一台巨大的超级计算机,实现各种异构系统中计算资源、存储资源、数据资源、信息资源、知识资源的全面共享和协同。Web服务技术则正逐渐成为解决异构分布式系统之间互操作性的一种主流技术。因此,在网格环境下,将Web服务技术应用于可视化领域是一个崭新的理念,其目的是利用Web服务技术,为可视化应用提供各种异构资源的管理、发现和共享,从而支持更多的用户在更广的范围内使用数量更大和分布更广的可视化服务,真正实现交互式、并行和分布式可视化。目前,对于这一新兴的研究方向,国内还未见相关研究报道,而国外也仅有少数大学处于起步阶段,研究工作尚缺乏系统性,基本的研究框架尚未形成,可供参考的文献甚少。针对这种现状,本文在深入研究相关理论与技术的基础上,对于如何将Web服务技术应用于可视化领域做了大量基础性和探索性的尝试,主要工作和贡献包括;●面向服务的可视化平台体系结构的研究探讨了将Web服务技术应用于可视化的可能性和必要性,分析了传统的可视化管道的特点和不足,提出了面向服务的分布式可视化管道模型,并在此基础上,设计了面向服务的分布式可视化平台的体系结构,该结构与Web服务体,系结构相吻合,充分体现了服务的提供方、服务的使用方(可视化用户)和服务代理方之间的相互关系,各部分分工明确,既相互合作,又相互独立,具有良好的通用性和可扩展性。●可视化本体的研究针对目前还没有可视化本体的现状,为了实现基于语义的可视化服务匹配,本文综合了可视化领域中K.W.Brodlie,Melanie Tory and Torsten Moller所提出的两个有代表性分类法,以提供可视化服务的语义描述为目的,构造了一个可视化本体,并应用于基于语义的服务发现中。实践证明,虽然该本体还需要不断完善,但是它确能反映可视化领域的核心概念以及它们之间的相互关系,较好地描述可视化服务的语义。●基于语义的可视化服务发布与发现机制的研究根据可视化服务的特点,提出了可视化服务描述模型,使得服务提供者和请求者可以用统一的格式描述服务;实现了基于向量空间模型的服务匹配算法,同时提出了一个基于本体的可视化服务匹配算法,该算法能较准确地计算出服务之间语义的匹配程度,有效地提高匹配的查全率和查准率,其成果已获得了国内外同行的好评;强调了服务的定位应该考虑服务质量问题,给出了服务质量相似度的计算公式。另外,采用J2EE技术架构基于语义的可视化服务发布与发现门户,在UDDI基础上,通过增加服务的语义描述层和服务能力匹配层来实现可视化服务的语义标注和语义匹配功能,并实现对服务语义信息的单独存储,完成了对各种可视化服务资源的统一管理并提供了有效的服务发现方式。该门户的模块性好、易于扩展,为管理和匹配服务提供了有力的支持。●面向服务的可视化系统研究随着网格与Web服务的融合,越来越多的资源会使用Web服务的形式提供,因此,设计并实现面向服务的分布式可视化系统具有非常重要的现实意义。它采用全Java的设计方案,消除了平台的异构性,以问题求解环境Triana为低层支撑环境并进行扩展和修改,降低了系统的复杂度和重复开发的工作量,实现了对可视化服务的发现、导入、组合和调用,提供了灵活地建构可视化管道的能力、支持交互式、分布式和并行可视化的实现。●面向服务的分布式可视化平台的实现与性能研究面向服务的分布式可视化平台由基于语义的可视化服务发布与发现门户、面向服务的可视化系统和各种可视化服务资源三部分组成。本文在较系统而全面地阐述网格环境下面向服务的可视化平台实现的同时,从定性和定量两方面,对其性能进行了测试和评估。通过一系列的研究、实际开发和实例测试表明,所研制的面向服务的分布式可视化平台,较全面地实现了系统的预期目标,能对网格中的各种可视化资源进行统一的管理与共享;为用户提供多种手段发现合适的可视化资源,从而使得数目繁多、分布广泛的资源能得到有效利用;方便用户构造可视化管道、能有效地利用远程数据进行可视化;实现了可视化结果的本地显示;支持交互式、并行和分布式可视化,加快了可视化速度,使得对大规模数据的可视化处理成为可能;支持简单的协作可视化,同时该系统具有跨平台能力、良好的可扩展性、不局限于某类应用问题,支持多种形式的可视化。因此,该平台是一个较完善的面向服务的可视化系统,工作量大,具有重要的理论意义和实际应用价值。更多还原

【Abstract】 As visualization technology is being widely applied into a lot of fields, such as medicine, geology, oceanography, meteorology, aviation, business process and so on, and the network develops further, the data, which needs to be visualized, are also becoming larger and more distributed, autonomic, heterogeneous and dynamic. The traditional visualization mode, which makes use of local resources or single resource, cannot process and compute these large data sets. So the distributed and parallel technologies should be used, and the traditional mode should be replaced by a new visualization mode. Nowadays, Grid Computing and Web Service technology represents one of the most promising advancements for today computational science and engineering. Grid is an abstraction allowing transparent and pervasive access to distributed computing resources. Other feature of the Grid is that the access provided is secure, dependable, efficient, and inexpensive, and enables a high degree of sharing and collaboration for a variety of resources, including computing resources, storage resources, data resources, information resources and knowledge resources. And Web Service is gradually becoming a mainstream technology for interoperation of heterogeneous and distributed systems. Therefore, it is a new idea to apply Web Service technology into visualization field. It aims to provide, by means of Web Service technology, management, discovery and sharing of heterogeneous resources for visualization, and support more users to utilize more visualization services and more distributed ones, and finally implement interactive, parallel and distributed visualization. Current research on service-oriented visualization is still in its infant stage. There is no report about it in domestic and few works have been done systematically in overseas. This dissertation is a relatively systematic research on how to apply Web Service into visualization. Our works and achievements include as following:·Research on architecture for service-oriented visualizationThe possibility and necessity of applying Web Service into visualization are discussed, and the characteristics and deficiencies of the traditional visualization pipeline are analyzed as well. And then a service-oriented pipeline is proposed. Based on it, a service-oriented architecture for distributed visualization is designed, which is similar to the architecture for Web Service, which illustrates the relationship among service providers, service requestors and service agents. Each component in the architecture is responsible for a group of distinct functionalities, and components can collaborate with each other. So the characteristic of extensibility and general purpose are achieved.·Research on ontology for visualizationIn order to implement semantic based matchmaking for visualization services and support a common vocabulary for semantic description of visualization services, however, as there is no useful ontology for visualization, the dissertation synthesizes two important classifications in the visualization field, and builds an ontology, which has been used in the visualization service discovery. The testing results show that it can describe those core concepts in the visualization and their relations, the semantic information of visualization services although it is still incomplete and tentative.·Research on semantic based publishing and discovering for visualization services Based on the characters of visualization service, a description model forvisualization service is proposed, which enables advertisers and requestors to describe service using a common model. A matching algorithm which is based on Vector Space Model is implemented. And an ontology based semantic matchmaking algorithm is put forward, which is an improvement to the quality of matchmaking -extending existing algorithms with a subsumption and semantic definition distance, which allows the algorithm to have the ability to precisely calculate a distance between concepts. Additionally, the dissertation presents QoS should be considered when the services are located, and gives the formula of QoS similarity. Meanwhile, J2EE is used to develop the portal for semantic based publishing and discovering for visualization services, which enables the management of a variety of visualization resources and provides an efficient mechanism for service matchmaking. The portal has modularity and extensibility.·Research on service oriented visualization system With the integration of Grid Computing and Web service, more and more resources will be provided by means of Web service. Therefore, the implementation of service oriented visualization system is very significant. The system adopts Java, which is platform independent, and utilizes the problem solving environment Triana as supporting, and modifies and extends it in order to realize the discovery, import, composition and invocation for visualization service and support the establishment of visualization pipeline and interactive, distributed and parallel visualization.·Research on implementation and performance of service oriented visualization platformThe dissertation not only systematically presents the implementation of service oriented visualization platform, but tests its performance from qualitative and quantitative aspects as well.A series of research, development and testing show that the service oriented visualization platform achieves the expected goal, which supports the management and sharing of various of visualization resources; provides three kinds of ways to discover the appropriate visualization services; facilitates the building for visualization pipeline and the process for remote data; allows a visualization to be displayed on desktop display; runs across multiple computers/resources; supports interaction within the visualization and parallel and distributed visualization so as to enable the visualization for large scale data sets; performs some simple collaborative visualization. And it is platform independent, and has extensibility and is not limited to the special application. So the work of the dissertation is a relatively systematic research and implementation for service oriented distributed visualization, which has significant both in theory and practice.更多还原