IRList Digest Sunday, 31 January 1988 Volume 4 : Issue 5 Today's Topics: Abstracts - New Dissertations (part 1 of 3) News addresses are Internet or CSNET: fox@vtopus.cs.vt.edu BITNET: foxea@vtvax3.bitnet ---------------------------------------------------------------------- Date: Thu, 28 Jan 88 22:42:30 EST From: "Susanne M. HUMPHREY" Subject: new dissertations Selected IR-Related Dissertation Abstracts Compiled by: Susanne M. Humphrey, National Library of Medicine, Bethesda, MD 20894 The following are citations selected by title and abstract as being related to Information Retrieval (IR), resulting from a computer search, using the BRS Information Technologies retrieval service, of the Dissertation Abstracts International (DAI) database produced by University Microfilms International. Included are the UM order number and year-month of entry into the database; author; university, degree, and, if available, number of pages; title; DAI subject category chosen by the author of the dissertation; and abstract. References are sorted first by DAI subject category and second by author. Citations denoted by an MAI reference do not yet have abstracts in the database and refer to abstracts in the published Masters Abstracts International. Unless otherwise specified, paper or microform copies of dissertations may be ordered from University Microfilms International, Dissertation Copies, Post Office Box 1764, Ann Arbor, MI 48106; telephone for U.S. (except Michigan, Hawaii, Alaska): 1-800-521-3042, for Canada: 1-800-268-6090. Price lists and other ordering and shipping information are in the introduction to the published DAI. An alternate source for copies is sometimes provided at the end of the abstract. The dissertation titles and abstracts contained here are published with permission of University Microfilms International, publishers of Dissertation Abstracts International (copyright by University Microfilms International), and may not be reproduced without their prior permission. AN University Microfilms Order Number ADG87-23759. AU HALL, DOUGLAS LEE. IN North Texas State University Ph.D 1987, 151 pages. TI A COMPARATIVE ANALYSIS OF GUIDED VS. QUERY-BASED INTELLIGENT TUTORING SYSTEMS (ITS) USING A CLASS - ENTITY - RELATIONSHIP - ATTRIBUTE (CERA) KNOWLEDGE BASE. SO DAI v48(08), SecB. DE Computer Science. AB One of the greatest problems facing researchers in the subfield of Artificial Intelligence known as Intelligent Tutoring Systems (ITS) is the selection of a knowledge base designs that will facilitate the modification of the knowledge base. The Class-Entity-Relationship-Attribute (CERA), proposed by R. P. Brazile, holds certain promise as a more generic knowledge base design framework upon which can be built robust and efficient ITS. This study has a twofold purpose. The first is to demonstrate that a CERA knowledge base can be constructed for an ITS on a subset of the domain of Cretaceous paleontology and function as the "expert module" of the ITS. The second is to test the validity of the ideas that students guided through a lesson learn more factual knowledge, while those who explore the knowledge base that underlies the lesson through query at their own pace will be able to formulate their own integrative knowledge from the knowledge gained in their explorations and spend more time on the system. This study concludes that a CERA-based system can be constructed as an effective teaching tool. However, while an ITS-treatment provides for statistically significant gains in achievement test scores, the type of treatment seems not to matter as much as time spent on task. This would seem to indicate that a query-based system which allows the user to progress at their own pace would be a better type of system for the presentation of material due to the greater amount of on-line computer time exhibited by the users. AN University Microfilms Order Number ADG87-22093. AU JIANG, WEI-SI. IN University of Cincinnati Ph.D 1987, 178 pages. TI A KNOWLEDGE SYSTEM USING HYBRID REASONING SCHEMES AND EXPLOITING A RELATIONAL DATA-BASE AS A FRAME-LIKE KNOWLEDGE BASE. SO DAI v48(07), SecB. DE Computer Science. AB This dissertation describes an expert system shell PAIS-I and several prototype systems developed using this shell. The PAIS-I system has a couple of special facilities to support hybrid reasoning schemes, and is capable of exploiting a relational database as a frame-like knowledge base. First generation expert systems reason from rules of thumb, or use heuristic reasoning. They have limited problem-solving ability and a fragile behavior at the boundary of the field domain. Model-based reasoning employs a different approach. In this approach, we first build a model of the system's structure, function and causality, and then reason about this model. With a specific problem domain-electronic trouble-shooting, three small prototype expert systems were developed using the PAIS-I shell. Each of them employs a different reasoning scheme: the first one uses heuristic reasoning only, the second one uses model-based reasoning only, and the third one combines the first two approaches and uses a hybrid reasoning scheme. The comparative study shows that the heuristic approach is of high efficiency, but the problem-solving ability is limited. The model-based approach has powerful problem-solving ability, but is inefficient. The combined approach supported by the PAIS-I shell can achieve high efficiency as well as powerful problem-solving ability. The special facilities of the PAIS-I shell enable the implementation of this hybrid reasoning scheme easier and more convenient than the existing shells. The PAIS-I shell has a direct access to an external database management system (DBMS) for fetching the information from the database. It also has a DBMS frame interpreter to transform the information into executable Prolog clauses representing a frame. With the support of these facilities, the system is capable of exploiting passive data in the database as active knowledge for making useful inferences. With the help of the PAIS-I system facilities, a hardware verification prototype was developed using a novel approach. An implementation of commonsense reasoning was also studied, which is able to solve well-known Whether Birds Can Fly and Temporal Projection problems. AN University Microfilms Order Number ADG87-21992. AU NAPOLIELLO, MICHAEL FELIX. IN Virginia Polytechnic Institute and State University Ph.D 1987 160 pages. TI A STUDY OF MANAGERIAL COMPUTER USERS: THE IMPACT OF USER SOPHISTICATION ON DECISION STRUCTURE AND ATTRIBUTES OF DECISION-RELATED INFORMATION. SO DAI v48(07), SecB. DE Computer Science. AB With the advent of information technology, MIS research has tried to understand and describe the impact of this technology on organizations. To date the vast majority of this research has focused on a macro-level of analysis. But the introduction of the microcomputer has significantly altered the focus of computing through the development of a body of managerial computer users. This study looked at the following questions: What factors constitute an information technology user environment? What are the usage and knowledge differences which constitute a concept of user sophistication? Do those differences significantly impact on a user's level of structured decisions and assessment of information attributes? To answer these questions a study was conducted of 229 middle managers in two academic institutions. The author developed a conceptual model of an information technology user to serve as the basis for the analysis. The study employed a multivariate regression analysis to test hypotheses developed from the user model. The results indicated that a positive relationship exists between managerial computer usage and a high perceived level of structured decisions. Furthermore, there was a strong association between a managerial user's level of computer understanding and his assessment of information reliability and sufficiency. The study also identified significant differences in a user's information technology environments and cognitive types. AN University Microfilms Order Number ADG87-20324. AU PARK, JONG-TAE. IN The University of Michigan Ph.D 1987, 225 pages. TI A KNOWLEDGE-BASED APPROACH TO MULTIPLE TRANSACTION PROCESSING AND DISTRIBUTED DATABASE DESIGN. SO DAI v48(06), SecB, pp1740. DE Computer Science. AB The collective processing of multiple transactions in a database system has recently received renewed attention due to its capability of improving the overall performance of a database system and its applicability to the design of knowledge-based expert systems and extensible database systems. This dissertation consists of two parts. The first part presents a new knowledge-based approach to the problems of processing multiple concurrent queries and distributing replicated data objects for further improvement of the overall system performance. The second part deals with distributed database design, i.e., designing horizontal fragments using a semantic knowledge, and allocating data in a distributed environment. The semantic knowledge on data such as functional dependencies and semantic data integrity constraints are newly exploited for the identification of subset relationships between intermediate results of query executions involving joins, such that the (intermediate) results of queries can be utilized for the efficient processing of other queries. The concept of the conventional query graph is extended to represent distributed transaction executions by the inclusion of site information. A state of the problem space is represented by this extended query graph. The expertise on the collective processing of multiple transactions is embodied into the rules of a rule-based expert system, MTP (Multiple Transaction Processor). These expert rules exploit large amounts of domain-specific semantic knowledge to reformulate the execution plans of queries such that the overall processing cost is substantially reduced. MTP employs the planning technique combined with search method where the plan step infers the necessary constraints, and the search step achieves optimal solutions utilizing the ${\rm A\sp\ast}$ or branch and bound search technique. In the second part, MTP is applied for the determination of horizontal fragments exploiting the semantic knowledge. Heuristics for allocating data in local area networks are developed. In summary, this knowledge-based approach adds to knowledge for the processing of multiple transactions in a distributed environment, and to the design of knowledge-based expert systems which require efficient access to a large knowledge-base implemented on (distributed) relational database systems. AN University Microfilms Order Number ADG87-20651. AU POTTER, TERRY WAYNE. IN State University of New York at Binghamton Ph.D 1987, 214 pages. TI STORING AND RETRIEVING DATA IN A PARALLEL DISTRIBUTED MEMORY SYSTEM. SO DAI v48(06), SecB, pp1740. DE Computer Science. AB The storage and retrieval of patterns in a Hopfield parallel distributed memory is investigated experimentally with a view toward increasing its storage capacity. The first two Chapters give an overview of distributed memories and in particular the Hopfield distributed memory. This is followed by a Chapter which experimentally identifies the basic storage capacity of the original Hopfield memory when using text patterns. This dissertation then experimentally investigates new and untested methods to increase the storage capabilities of a Hopfield memory. Increasing the storage capacity by using the continuous-valued Hopfield memory is explored in Chapter 3 and the impact on capacity of data representation is experimentally investigated in Chapter 4. We then focus on new ways of storing data (changing the interconnect strengths) including in Chapter 7 developing a new method called Modifying the Energy Contour- MEC. In addition, this Chapter also outlines how to increase error-tolerance through the use of noisy patterns. The Hopfield memory is then contrasted to another intelligent memory subsystem based on more of a traditional computer technology. In Chapter 8 we see that traditional computer technology using data-parallel techniques has a greater storage efficiency than possible with current Hopfield distributed memories. The design of this data-parallel memory is based in part on what is learned experimentally from the preceding Chapters on the Hopfield memory. This fast data-parallel approach also supports retrieval of data patterns with noisy inputs although it does not have all the functionality of the Hopfield distributed memory. The following three results are the most significant outcomes of this dissertation. Experimentally, it was determined that: (1) The Hopfield memory during recall did a parallel, nearest-neighbor pattern search procedure. (2) The storage capacity of the Hopfield memory can be significantly improved but the storage efficiency is far less than data-parallel based associative memories. (3) A data-parallel implementation of the Nearest-Neighbor Rule provides for fast parallel search of pattern space and can support software-based learning procedures. This implementation can then behave as a Parallel Associative Memory dealing with inexact data in the recall key. [Note: more in issues 6 and 7 - Ed] ------------------------------ END OF IRList Digest ********************