1. The source data could contain different types (such as documents, spread sheets, pictures, images, GIS maps, multimedia files, and databases) and in various formats. The data could be distributive at networked computers.
2. The metadata and data catalog shall be accessible from a central point (a server computer) without physically accessing the original data.
3. Client could register, maintain, search or access the data from remote computers and use the data in various applications.

Figure 1 IIMS Client for Searching Catalog and Downloading Dataset

Figure 2 Scenario of Application of IIMS in E-Government

1. There are multiple organizations each independently established its own IIMS DSS system. So each has its own metadata server.
2. Different groups have different metadata standards and management rules; this makes a single metadata server impossible.
3. For a large organization, particularly with geographically distributive branches, the metadata volume could be too large to be hosted by a single metadata server.

1. Dynamic distributive database connection;
2. On-line data encryption/decryption for enhanced data security;
3. On-line data compression to reduce server space usage and data downloading time;
4. On-demand data extraction for remote sensing imagery, digital maps, OLAP, etc.;
5. Data format conversion; and
6. Accounting for data on-line trading (e-commerce).

2. Owner wants only authorized persons to modify its data when necessary.
3. Owner requires that its data are only seen and used by certain people, because of non-disclosure restrictions, or for the purposes of selling data.
4. User needs to be sure the data are the original version published by its owner.

1. User account will be verified through a central user database at IIMS metadata server when accessing metadata or data from any registered distributive data server. User doesn抰 need to be registered repeatedly to each data server.
2. Only the users authorized by system manager can upload data files to a data server. This helps to prevent illegal occupation of disk space at data servers.
3. The owner of a dataset can allow only users belong to certain user groups to be able to view and access its data. The catalog will be hidden from users who have no authority to access the dataset. The owner can also assign only certain users to have the authority to modify the catalog and the linked dataset. This function allows a user to assign different security-level to each dataset with maximum flexibility. For example, financial report dataset may be only assessable to high-rank officials; planning map dataset may be only available to planners before publication, while announcement dataset can be opened to every staff.
4. Data files at a data server can not be accessed directly, but must through the IIMS data server access service. Thus, all access is under security/authority control of IIMS.
5. Each access and operation from IIMS user will be recorded in IIMS log database, IIMS manager can read the log information to monitor and trace illegal use of system and data.
6. Concurrent editing of a dataset is controlled by locking/unlocking functions to make sure the modification on data is not lost.
7. Data user can query IIMS to show real owner information to assure no fake data publication.
8. As a supplementary security, data owner could make its dataset encrypted when uploading to IIMS. Users shall then contact the owner to get a proper key to decrypt the dataset at downloading.
   

1.6 GIS Data Interoperability
Interoperability is a big issue. Because different GIS systems may be connected to the network, the data resources may be in various formats and projections. Without data interoperability, on-line access is meaningless and on-line processing is impossible. Ideally, every GIS on the network will provide a unique interface for data access, as defined by OpenGIS specifications. Otherwise the data format/projection conversion services shall be provided by the data server, so the user or applications can get the data in its needed format.

IIMS provides a GIS format converter to provide GIS format and projection conversion services on the data server. Most popular GIS data formats, such as ArcView Shape, Arc/Info E00, MapInfo MIF, AutoCAD DXF, USGS, DLG, G-XML, and some native formats often used in Japan, are supported.

1.7 Networking GIS
A GIS system called GeoBasic? which has been developed by Basic Engineering Co., Ltd. is integrated with IIMS to provide viewing and manipulating functions of distributive Geo-Spatial Data (Ren et al. 1998). Within GeoBasic, users can directly search digital maps and images registered to IIMS and stored in distributive data servers, and directly load the data into GeoBasic for viewing, analyzing or plotting. Users can also create or modify maps and register to an IIMS data server for real-time sharing with other users. Other GIS can be integrated with IIMS through IIMS API too. Figure 3 shows the concept of integrating distributive data from different departments through IIMS.

Figure 3 Integration of Distributive Spatial Data Through IIMS

1.8 Web Access
IIMS supports two client modes: Java Client and Web Client. Although IIMS Java Client can be used to access IIMS servers through either Intranet or Internet, but for assuring security or avoiding client installation, web client accessed can be supported. Web client is for external users to access the catalog services and Geo-Spatial data through Internet with a commercial web browser, such as IE or Netscape. Web Client or Web GIS can access the data servers through IIMS Web Server, so web user can use up-to-date data in real-time. All transmission for Web access is through XML. IIMS can be a backbone system of Web GIS to manage the server data and supply data in real-time from distributive data servers.

2. Application of IIMS in E-government Projects

2.1 Prefecture Networking GIS
Participating the national-wide e-government (e-Japan) movement, a pioneer Prefecture in Japan has recently acquired IIMS and GeoBasic and established a data sharing networking GIS for the government of the Prefecture. Leading by the Information System Department, totally twelve departments have participated the data sharing system, covering the data and management in construction, river, road, sanitation, environment, culture, natural resource, and disaster prevention. Each department creates and maintains data generated for its own business. All data are registered to an IIMS metadata server managed by the Information System Department for sharing with other departments. GeoBasic and IIMS Client are installed for individual users in each department. GIS data are registered and manipulated through GeoBasic, the integrated GIS tool for IIMS.

The scenarios of the prefecture GIS is shown in Figure 4.

Figure 4 Scenario of Japanese Prefecture GIS

2.2 River Information Management System
A major river management office in middle Japan has acquired IIMS and established a distributive river information management system. This management office, with 12 divisions, 9 filed brach offices, and around 150 staffs, has the responsibility to monitoring and manage 11 important rivers. Over 100 projects are implemented and over 1500 license applications are received in each yaer. Various types of data are gathered and shall be managed. Among them the most important are:

• Project data
• Construction data
• Check porint data
• License application data
• Disaster information

The formats are diversified, such as documents, forms, CAD drawings, digital maps, and pictures. All those different types of data are now registered to a river information management system based-on IIMS (Figure 5). Staff from the different devisions in headquarter and geographically distributive brach offices can search and access the databases from anywhere through Intranet or Internet. More importatantly a knowledge database is also created on IIMS to share the intellenece information among staff in job training and solving problems. The work effiency and information management are greatly improved. In near future the system will be extended to include other kinds of data and support various business applications.

Figure 5 IIMS for River Information Management

2.3 Technical Data Sharing System

An organization in Japan is now implementing a project to integrate and share the technical data and information for improving space equipment manufacturing and operation. IIMS is chosen as the backbone of the technical data sharing system. The data that will be managed and shared through IIMS include the following:

• Standard business documents (regulations, specifications, requirements, etc.)
• Technical information (technical information from domestic/foreign space agency and manufacturers, reports, analytic data, image data, CAD data, knowledge data, etc.)
• Internal documents (meeting minutes, travel reports, etc.)
• Purchased book and paper materials.

The technical data will be able to be exchanged among domestic agencies as well as with foreign agencies (Figure 6).

Figure 6 The Conceptual Structure of the Technical Data Sharing System

2.4 Geospatial Data Sharing System
Five Universities in Japan have been cooperating in Yakushima Zero Emissions Project, a research project on resource recycling and sustainable society model. Rich results and data have been developed by participating institutions. To enforce the sharing and exchange the information and data, particularly the base map and spatial database of Yakushima, among participating researchers, a spatial data sharing system is being developed using IIMS.

The five participating Universities are:

• United Nations University (UNU)
• Kagoshima University
• Tokyo Institute of Technology
• Aichi Gakuin University
• Toyohashi University of Technology

Figure 7 shows the sample screens of web interface of the system. Figure 8 shows the hardware and software configurations of the system.

Figure 7 Web Interface of Kagoshima Zero Emissions Project Spatial Data Sharing System

2.5 Digital City
Digital city is another name for e-government at municipal level in China. The objective of Digital City is to promote digitization and utilization of urban information resources through an integrated data management and sharing system, and improve the information service to government agencies, enterprises and the public.

Chengdu city, the capital of Sichuan province, is a pioneer in digital city construction in China. At the first phase, IIMS was adopted to develop an Urban Information Resource Management Platform. The system is composed of three tiers as shown in Figure 9. Data Tier is the base for creating and maintaining data resources. Management Tier is realized by IIMS providing fast metadata query and distributive data accessing capabilities. Through the IIMS data sharing system, the Service Tier provides services to various data and information users.

Figure 10 and 11 present two typical application scenarios of the data sharing system in Digital Chengdu.

Figure 8 Hardware/Software Configurations of Kagoshima Zero Emissions Project Spatial Data Sharing System

Figure 9 Three Tiers of Data Sharing System for Digital Chengdu

Figure 10 Sharing Information to Support Decision Making

Figure 11 Sharing Information to Support Disaster Mitigation

2.6 Disaster Prevention System
A national agency for disaster prevention in Mexico has started a project for establishing the National Atlas of Risks (ANR, by their letters in Spanish) and the System for Identification of Risks of Disasters in Mexico (Siiride, by their letters in Spanish).

Those projects demand the extensive use of shared information among departments and institutions. Basic Engineering Co. Ltd. is invited to develop the solutions on shared information systems that could satisfy their requirements by using IIMS Technology.

The National Atlas of Risk is a project for incorporating all information related to risk of disasters in Mexico. The main goal is to create an information system that evolves in time by the distributed aggregation of digital files. As an initial step, a shared information system for generating all the basic information for the ANR will be developed for all the different departments to contribute with their files and databases.

The following data will be included into the data sharing system:

• Informative Maps
• Reports of Popocatepetl Volcano
• Reports of Hurricanes
• Industries with hazardous substances
• Database of chemical accidents
• Seismic Events

The Siiride is a complex system for risk assessment. The integration with IIMS is fundamental for making analysis for different governmental dependencies. Each of those dependencies has their own requirements for using the information maintained by IIMS. Therefore, several different models for risk assessment and analysis must be shared through the solution. Figure 12 shows the general architecture and data flow of the system.

Figure 12 General Architecture and Data Flow of IIMS-ANR-Siiride System

References

• Fuhu Ren, et al. 1998, Information Infrastructure Management System (IIMS) and Networking GIS. Proceedings of UM3?8 International Workshop on Urban Multi-Media/3D Mapping, Tokyo, Japan, 88-95
• Kenji Endo and Fuhu Ren. 2001, IIMS-A Data Sharing Platform for Networking GIS, Asian Journal of Geoinformatics, 1, 4, 91-96