DL-Raid: An Environment for Supporting Digital Library Services

Digital libraries are a repository of documents that are large volumes of integrated text, image, video and sound data. In such an environment, users may not have an eecient access mechanisms for the data, and in some cases may not even know what is available and how and where it is located. To facilitate the users in retrieving the documents from this vast information base, digital libraries must provide interactive support. This will allow the users to enter into a dialogue with an information base server and successively reene the query if the query is not suucient to locate the desired information. In a wide area network (WAN), such a dialogue will be communication intensive. We are currently developing a digital library prototype called DL-Raid at the Raid laboratory at Purdue University to study the feasibility and sensitivity of various retrieval schemes in distributed environments. In this paper, we present the architecture of the DL-Raid and the data model supported by this prototype. We investigate the partial content-based retrieval schemes in the prototype. We present the results of various communication experiments with large data objects and analyze these results to study their eeects on the eecient retrievals of data in the digital library environment.