Research And Development Of Service_Oriented Distributed Visualization In Grid

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.