A Study on resource discovery mechanism in distributed information networks

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The aim of this research was to investigate methods for managing, identifying and locating information which is distributed over a wide-area network, such as the Internet.In applications such as digital libraries, users tend to access and retrieve objects, e.g., pages of scientific paper, pictures, and numerical data without knowing actual locations of the objects. In this research, these materials are abstractly termed as 'information resource' and a general approach to look for identifiers of resources based on the description of attributes of the specific information resources.In actual environment in the Internet, users have to use URLs or other location information, since these are identifiers of information resources which shows the storage locations. However, it is not easy to get appropriate identifiers. The new concept of URS (Uniform Resource Specification) is proposed and this gives a persistent capability to resolve object description composed of the attribute specification … More into URL,thus allowing users to issue a query without knowing exact location of information.The software architecture employed in this investigation is based on a client-server model, and we adopted ANSI Z39.50 protocol standard for this purpose. What we needed is a light-weight protocol for experimental purpose, therefore, we modified and simplified Z39.50 for a name resolution purpose.The name resolution server returns an identifier of information object, upon the request from a client giving URS.The mechanism employed for this resolution is a simple method according to rule-based algorithm. From a practical aspect, compatibility with HTTP based accesses is also required, thus a gateway mechanism between a HTTP server and a URS resolver was also experimentally implemented. conventional HTML browser can be used to access to URS resolver through this gatewasy.The research was pursued through 1996 to 1997 and we think that our prototype implementation shows the feasibility of the proposed concept. Evaluation of the details of the prototype is still going on for further evolution of the approach. Less