Study on Data Collaboration Service for Collaborative

Virtual Geographic Environment

Jun Zhu1,2, Jianhua Gong1, Hua Qi 3, and Tao Song4

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^{1 State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications,}

^{Chinese Academy of Sciences, Beijing 100101, P.R. China}

^{2 Key Laboratory of Poyang Lake Ecological Environment and Resource Development，}

^{Ministry of Education}

^{vgezj@163.com}

^{3 Surveying Engineering Department, Southwest Jiaotong University, 610031, P.R. China}

^{4 GIS Lab, Department of Geoinformatic Engineering, Inha University, Yonghyundong 253,}

^{Namgu, Inchon, S. Korea, 402-751}

Abstract. The use of Collaborative Virtual Geographic Environments (CVGE) is one of the most promising uses of virtual reality in geographic field. Data collaboration can support multi-directional sharing of data and files, allowing ideas and thoughts to be communicated interactively among users. Thus how to integrate diverse and separated data and offer more convenient and intuitive data collaboration service becomes increasingly significant for implementing collaborative work in the CVGE. In this paper, we firstly design a Grid-based CVGE service framework and discuss the data searching mechanism and accessing control. A data collaboration service was built to integrate and share system internal resources and improve collaboration work efficiency. Finally, we built a collaborative virtual environment and implemented data collaboration service in silt dams system planning on a case study area, Jiu-Yuan-Gou watershed of Loess Plateau, China. Experiment results prove that the scheme addressed in the paper is efficient and feasible.

1 Introduction

In recent years, the amount of spatial data is becoming more and more tremendous [1]. However, a lot of data cannot be used efficiently because the rapidly increasing amount of data precludes the presentation of all given data items and the complexity of many datasets surpasses the user’s ability to identify the gist or the underlying concepts [2]. Essentially, solving geographic problem is a process of collaborative work among group members, which are often distributed in geographic space [3]. To facilitate the analysis of simulation data, a variety of experts may be needed. As an integrated technology, collaborative virtual geographic environment (CVGE) offers an tuitively and efficiently interactive visualization environment. The CVGE might vary in its representational richness from 3D geographic spaces, 2.5D and 2D environments to text-based environments, which allows eographically separated users to explore complicated spatial information and conduct collaborative work [4,5]. An essential achievement of the CVGE is that it combines the participants and the information it accesses and manipulates in a single virtual geographic space.

Hence improving the efficiency of data collaboration is very important to keep synchronization in the CVGE collaborative work. In fact, many related works have been implemented to resolve some certain application cases. For example, a visualization environment in a single computer has been developed. So how to integrate data, procedures and algorithms to build and offer more convenient and intuitive data collaboration service in heterogeneous and geographically dispersed environments becomes increasingly significant for collaborative work in the CVGE.

The development of Grid technology endows the CVGE with a promising future. Grid’s concept is coordinated at sharing resources and solving problems in dynamic, multi-institutional virtual organizations [6]. The Grid computing system can provide different kinds of services for users [7,8]. Essentially, Grid user sees a large virtual computer despite of the fact that the resources are geographically distributed and connected over the worldwide networks [9]. Based on the concepts and technologies of Grid and Web Service communities, this architecture defines the uniform exposed service semantics (Grid Service). The OGSA (Open Grid Services Architecture) [10] can provide building blocks that can be used to implement a variety of higher-level Grid services such as distributed data management services. This framework is very flexible because services can be implemented and composed in a variety of different ways.

By using Grid computing, the CVGE can integrate and share all internal resources to create a big high-performance computing environment. Since the core of the OGSA is the service idea, the OGSA-based CVGE can integrate services across distributed, heterogeneous and dynamic collaboration environment formed from the disparate resources with a single system and/or from external resources sharing and service provider relationships. In this paper, we pay attention to build up a data collaboration service to high-efficiently support collaborative work in the CVGE.

The rest of this paper is organized as follows. In section 2, we focus on how to build a data collaboration service, some key problems such as Grid-based CVGE service framework, data searching mechanism, data accessing control and service implementing are discussed in detail. A simple prototype system was developed and a

data collaboration experiment was implemented as shown in section 3. Finally, some concluding remarks are given in section 4.