Browsing by Author "Weaver, Marybeth T."

Now showing 1 - 2 of 2
  • Thumbnail Image
    A Frame-Based Language in Information Retrieval
    Weaver, Marybeth T.; France, Robert K.; Chen, Qi-Fan; Fox, Edward A. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1988)
    With the advent of the information society, many researchers are turning to artificial intelligence techniques to provide effective retrieval over large bodies of textual information. Yet any AI system requires a formalism for encoding its knowledge about the objects of its knowledge, the world, and the intelligence that it is designed to manifest. In the CODER system, the mission of which is to provide an environment for experiments in applying AI to information retrieval, that formalism is provided by a single well defined factual representation language. Designed as a flexible tool for retrieval research, the CODER factual representation language is a hybrid AI language involving a system of strong types for attribute values, a frame system, and a system of Prolog-like relational structures. Inheritance is enforced throughout, and the semantics of type subsumption and object matching formally defined. A collection of type and object managers called the knowledge administration complex implements this common language for storing knowledge and communicating it within the system. Of the three types of knowledge structures in the language, the frame facility has proven most useful in the retrieval domain. The factual representation language is implemented in Prolog as a set of predicates accessible to all system modules. Each level of knowledge representation (elementary primitives, frames, and relations) has a type manager; the frame and relation levels also have object managers. Storage of complete knowledge objects (statements in the factual representation language) is supported by a system or external knowledge bases. One paper discusses the frame construct itself, the implementation of the knowledge administration complex and external knowledge bases. and the use of the construct in retrieval research. The paper closes with a discussion of the utility of the language in experiments.
  • Thumbnail Image
    Implementing an Intelligent Retrieval System: The CODER System, Version 1.0
    Weaver, Marybeth T.; Fox, Edward A. (Department of Computer Science, Virginia Polytechnic Institute & State University, 1988-05-01)
    For individuals requiring interactive access to online text, information storage and retrieval systems provide a way to retrieve desired documents and/or text passages. The CODER (COmposite Document Expert/effective/extended Retrieval) system is a testbed for determining how useful various artificial intelligence techniques are for increasing the effectiveness of information storage and retrieval systems. The system, designed previously, has three components: an analysis subsystem for analyzing and storing document contents, a central spine for manipulations and storage of world and domain knowledge, and a retrieval subsystem for matching user queries to relevant documents. This thesis discusses the implementation of the retrieval subsystem and portions of the spine and analysis subsystem. It illustrates that logic programming, specifically with the Prolog language, is suitable for development of an intelligent information retrieval system. Furthermore, it shows that system modularity provides a flexible research testbed, allowing many individuals to work on different parts of the system which may later be quickly integrated. The retrieval subsystem has been implemented in a modular fashion so that new approaches to information can be easily compared to more traditional ones. A powerful knowledge representation language, a comprehensive lexicon, and individually tailored experts using standardized blackboard modules for communication and control allowed rapid prototyping, incremental development and ready adaptability to change. The system executes on a DEC VAX 11/785 running ULTRIX (TM), a variant of 4.2 BSD UNIX. It has been implemented as a set of MU-Prolog and C modules communicating through TCP/IP sockets.