Xiaowu Chen

A CGSP-Based grid application for university digital museums

In order to effectively integrate and share the enormous dispersed resources of various digital museums, University Digital Museum Grid (UDMGrid) has been developed to provide one-stop information services about kinds of digital specimens in the form of grid services, based on ChinaGrid Support Platform (CGSP), which is a generic grid middleware serves well in various grid applications. This paper not only presents the overall architecture of CGSP-based UDMGrid, but also the ontology and its services, heterogeneous database access and integration, the logging and monitoring in UDMGrid, which are indispensable to UDMGrid, but not yet contained by CGSP, and can be easily incorporated to CGSP.

UDMGrid: A Grid Application for University Digital Museums

Because the eighteen online university digital museums of China confront a problem that the multi-discipline resources at these digital museums are isolated and dispersed without sufficient interconnection, ChinaGrid (China Education & Research Grid) supports a project named UDMGrid (University Digital Museum Grid), which studies a grid application for University Digital Museums using grid technology, especially information grid technology. According to the analysis on the problem, UDMGrid focuses on the resource sharing, information management and information service about those university digital museums. This paper presents research work on UDMGrid’s framework, metadata, replica management, application server, etc.

The Progress of University Digital Museum Grid

ChinaGrid provides the nationwide grid computing platform and services for education and research purpose among 100 key universities in China. University digital museum grid (UDMGrid) is one of the most important applications of ChinaGrid which aims at offering one-stop information services about kinds of digital specimens from several university digital museums in the form of grid services. During last 3 years, many versions of UDMGrid have been developed. This paper describes the progress of UDMGrid and presents key technologies of the current version such as ontology, Grid-DAI and grid monitoring. Finally, the workflow of UDMGrid is given

Research on database access and integration in UDMGrid

UDMGrid (University Digital Museum Grid) is devoted to the integration and sharing of resources from various university digital museums whose main carriers of resources are heterogeneous databases dispersed throughout CERNET. This paper presents the UDMGrid-DAI for database access and integration in UDMGrid. It merges decades of various databases in UDMGrid into several virtual databases oriented some certain domains, and provide consistent access interface and uniform logic view of these databases for the developer of grid applications.

OOML-Based ontologies and its services for information retrieval in UDMGrid

In order to effectively integrate and share the enormous dispersed resources of various digital museums, University Digital Museum Grid (UDMGrid) has been developed to provide one-stop information services about kinds of digital specimens in the form of grid services. To eliminate the heterogeneity between the information resources, shared concepts for these digital museums are indispensable. This paper studies OOML-based ontologies and its services for information retrieval in UDMGrid, including the object oriented ontology construction and ontology mapping, in which a novel inheritance mechanism is proposed to eliminate logic confusion. On the basis of OOML-based ontologies, ontology services are developed to assist the information retrieval by transforming global concepts to local concepts.

Toolkits for ontology building and semantic annotation in UDMGrid

University Digital Museum Grid (UDMGrid) has been developed to provide one-stop information services about kinds of digital specimens in the form of grid services. In order to speed up the way to make the digital specimen information resources interoperable based on semantic annotation using ontologies, three toolkits have been exploited to support the ontology building and the semantic annotation about the university digital museum information resources. These include toolkits for ontology editing, web content semantic annotation, and database content semantic annotation.

A distributed workflow management model for grid middleware

Workflow management enables grid service composition and user collaboration in grid middleware, it includes the workflow of grid service invoking and data exchanging among services. Because of the large requirements of grid service composition, its necessary for the workflow management to be scalable in many grid application systems. This paper proposes a distributed workflow management model for grid middleware, it is comprised of three modules including workflow definition tool (WDT), workflow balancer (WB), workflow execution engine (WEE) and defines the interfaces between workflow management and other grid components. Firstly, WDT composites grid services into workflow service, secondly WB dispatches workflow services and workflow job requests, thirdly WEE is up to the execution of workflow jobs. Furthermore, it describes the interfaces between workflow management and related grid components, such as job management, information service and grid portal. Also it divides the interfaces into WEE management, workflow service management and workflow job management. With the implementation and experiments of this model for Chinese education and research, its support platform middleware, its usability is verified through the usage of workflow tools in image processing scenario, its scalability and load balancing ability are proved in workflow scheduling test.

User's Vision Based Multi-resolution Rendering of 3D Models in Distributed Virtual Environment DVENET

Funded by National High Technology 863 Project, the distributed virtual environment network DVENET has been focused at incorporating realistic 3D visual simulation into a joint exercise. Visual tracking allows visual simulation to measure visual field and visual angle relied on by multiresolution rendering techniques including LOD (level of detail), morphing and LOL (level of light), which economize the computational cost. Based on vision perception of user, this paper describes our recent research in real-time multiresolution rendering of 3D models in virtual environment. This method calculates the critical parameters, such as view-distance, imaging parameter, brightness parameter, and so on, which control the switches between neighbor multiple resolution models and are correlative to users visual field and visual angle. It might also be utilized for kinds of simulators responding to the presence of the multi-resolution target but based on the special visions of infrared equipment or radar.

A dynamic awareness model for service-based collaborative grid application in access grid

Access Grid is an ensemble of resources that can provide an immersive, interactive, and collaborative environment for grid applications. Collaborative awareness support is a basic requirement of Access Grid, and is needed to provide adequate awareness information for collaborators to effectively cooperate with grid applications. However, most existing collaborative awareness models are unable to characterize the dynamic relationships between collaborators and their tasks with the standards of OGSA and WSRF. Therefore, this paper presents a dynamic collaborative awareness model, which characterizes above dynamic relationships for service-based collaborative grid applications in Access Grid. Based on the dynamic properties of services and the relationships between collaborators and services, this model firstly calculates the degrees of correlations between the actions of collaborators, and quantifies the intensities of each collaborators awareness of other collaborators actions, secondly divides awareness spaces by comparing the awareness intensities with their thresholds, thirdly selects and filters cooperation information according to the awareness spaces. Finally, the usability of this model is evaluated with the heuristic method, and an experiment is given to demonstrate that this model can increase the efficiency of cooperative work in Access Grid.

A Distributed Workflow Management Approach in CGSP

Workflow management technologies play a very important role in constructing grid application environment by automating service composition and execution. With the fast spread of grid technology, workflow management system should be flexible to meet increasing requirements of service composition. This paper introduces a distributed workflow management approach DWM4CGSP named distributed workflow management for CGSP, which can improve capability of workflow execution by dynamically assimilating new workflow engines and balancing workload among these engines. Moreover dynamic load balancing is applied in DWM4CGSP in order to make workload on each engine at reasonable level. Finally an implementation demonstrates that DWM4CGSP works well in CGSP and can be further extended to other similar grids