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IRList Digest Volume 4 Number 29
IRList Digest Saturday, 30 April 1988 Volume 4 : Issue 29
Today's Topics:
Abstracts - Abstracts of interest from Susanne Humphrey
News addresses are
Internet or CSNET: fox@vtopus.cs.vt.edu
BITNET: foxea@vtvax3.bitnet
----------------------------------------------------------------------
Date: Fri, 29 Apr 88 21:55:41 EST
From: "Susanne M. HUMPHREY" <humphrey@MCS.NLM.NIH.GOV>
Subject: abstracts of possible interest
[Note: The usual copyright and other restrictions go along with this
submission -- see earlier similar submissions by Susanne for the actual
wording. - Ed.]
AN University Microfilms Order Number ADG87-27184.
AU ABRAMS, DAVID HOWARD.
IN Georgia Institute of Technology D.B. 1987, 220 pages.
TI A REFERENCE MODEL FOR HETEROGENEOUS DATA BASE MANIPULATION AND AN
EXPERT SYSTEM PROTOTYPE FOR HOMOGENEOUS DATA BASE MANIPULATION.
SO DAI V48(09), SecB.
DE Computer Science.
AB A reference model for heterogeneous database manipulation (HDBM)
is presented. The model provides a generalized approach for
allowing applications software to perform data manipulation on
centralized or distributed heterogeneous database systems. The
HDBM model has been developed using layering and techniques
similar to those used in the International Standards
Organization's reference model for open systems interconnection.
A working prototype system, based on the HDBM model and called the
Integrated Data Delivery Expert (IDDE), was developed as a series
of layers using rapid prototyping methodology and expert systems
technology. The IDDE serves as a front-end system for manipulating
data in a distributed, relational, database system environment.
The IDDE software is developed as four layers: applications
interface; data presentation services module; data control
services module; and database services module. The IDDE model was
tested by retrieval of data from database systems that are
accessible to it.
The prototype has been shown to process data retrieval requests
successfully from the distributed, relational, database system
environment. Sample IDDE executions, as well as the prototype
source code, are included.
The dissertation addresses several future research possibilities
and implications.
AN University Microfilms Order Number ADG87-26875.
AU CHEN, HSING LUNG.
IN Illinois Institute of Technology Ph.D 1987, 175 pages.
TI OBJECT-ORIENTED ALERTER SYSTEM DESIGN.
SO DAI V48(09), SecB.
DE Computer Science.
AB Database systems are usually 'passive.' Database alerting
techniques provide a database system with the capability to take
actions by itself. Hence, the database system with alerting
techniques can play a more intelligent role. The primary objective
of this research effort is the development of a distributed
intelligent database system. This design problem encompasses the
issues of the development of methodology to decompose the complex
alerters into simple alerters, the investigation of algorithm for
allocating the simple alerters and design of protocol for ensuring
that alerters correctly monitor database. The proposed system is
useful in office information systems, decision-support systems and
user-friendly specification of 'chip' expert systems.
We approach the problem of monitoring database updates by using
the object-oriented approach. A methodology is proposed to
decompose a complex alerter into several objects. These objects
form a tree-structure. Each object can be considered as monitoring
a virtual database view. If the database view is updated, the
updated message is sent up the tree for further monitoring. The
top object can check whether alert condition is met and then
invoke the alert action.
An alerter can usually be expressed in terms of an associated
query on database view. The conventional approach for implementing
the complex alerters is that the database view is constructed
whenever related elementary relations are updated. The response
time of view-construction approach is longer than that of
object-oriented approach. However, object-oriented approach needs
much more space to store customized alerters. Another approach we
proposed is the combination of both approaches. The performance of
three approaches is compared. The combination approach can achieve
better time-space tradeoff.
If the object-oriented approach is applied in the centralized
computer systems, the complex alerter can be correctly invoked.
But in the distributed systems, the actions which should be
invoked may be missing or the extraneous actions are invoked. Some
concurrency-control methods are proposed to make sure that the
complex alerters monitor the database updates correctly in the
distributed systems.
Some allocation algorithms are also proposed to allocate the
alerting objects so that the response time is minimal under
object-number constraints.
AN University Microfilms Order Number ADG87-26878.
AU HARR, HENRY MAXIM.
IN Illinois Institute of Technology Ph.D 1987, 160 pages.
TI ABF: AN EXPERT SYSTEM FOR OFFICE AUTOMATION AND AN INTERPRETER FOR
LEGAL DOCUMENT CONSTRUCTION.
SO DAI V48(09), SecB.
DE Computer Science.
AB The ABF system creates an environment for document construction
that allows people who have never used a computer before to create
complex client-specific drafts. Legal experts develop model
documents and templates in ABF; then law students and paralegal
personnel process these documents in the same system, answering
system-generated questions about the client to produce a
custom-tailored version. The ABF system protects the user from the
operating system in every conceivable way. It provides facilities
for copying, storing, formatting, displaying, printing, and
deleting documents. It allows the user to convert documents to and
from MS-DOS ASCII files and organize them into libraries. It
supplies the same editing facilities whenever the user presses a
key, whether in answering a question, giving a command, or editing
a document. During the interviewing process the system
automatically constructs a client data file from answers to
questions; that file is searched for relevant information any time
that questions are asked as documents are processed for that
client. Model documents are ABF programs in disguise; ABF contains
all the facilities for conditionals, looping, multiple-values, and
subroutines provided by any modern programming language. In
addition the ABF user can modify the program while it is running.
The user can also switch contexts at any time from editing to
processing a document or issuing a command. If the system finds an
error, it puts the user in the editor with the cursor pointing to
the place where the error occurred. Although the system was
originally designed for use by lawyers, paralegal personnel, and
law students, it embodies new techniques for automating any office
that produces documents of a repetitive nature. ABF is a cross
between an expert system shell and an interpreter, embedded in a
sheltered microcomputer environment.
AN University Microfilms Order Number ADG87-26879.
AU HSIEH, CHENG-YUAN
IN Illinois Institute of Technology Ph.D 1987, 146 pages.
TI OFFICE PROCEDURE LANGUAGE: AN OBJECT-ORIENTED APPROACH.
SO DAI V48(09), SecB.
DE Computer Science.
AB This thesis presents the concept and design of a general-purpose
programming language: Office Procedure Language (OPL). OPL is
based upon a formal model for the specification of knowledge-based
information system, the OPM model. From the database viewpoint,
the OPM model utilizes the database alerting techniques to serve
the purpose of office activities management. OPL is developed to
specify an OPM model with object-oriented approach. An OPL program
can be translated to the corresponding OPM model. The OPM model
consists of databases, messages, office activities and alerter
rules. The general goals of the OPM model are (1) to describe the
relationships between these office objects; (2) to provide a
perspective view for the coordination and integrating of office
activities; and (3) to facilitate the protocol analysis and the
verification of office procedures. OPL is the linguistic interface
between OPM model and system programmers. It is a high-level
language developed to meet the specification requirements of the
above goals.
In OPL, the mechanism of database-altering is used to specify the
knowledge of an Office Information System (OIS). OPL is developed
for OIS design, where knowledge is expressed as database alerter
rules. However, due to its generality, it is also applicable to
the design of general information systems.
AN University Microfilms Order Number ADG87-26518.
AU MYAENG, SUNG HYON.
IN Southern Methodist University Ph.D 1987, 175 pages.
TI THE ROLES OF USER PROFILES IN INFORMATION RETRIEVAL.
SO DAI V48(09), SecB.
DE Computer Science.
AB One difficult problem in information retrieval (IR) is the proper
interpretation of user queries. It is extremely hard for users to
express their information needs in a specific yet exhaustive way.
From a different perspective, user variability in information
seeking behavior is not well reflected in a query. As an effort to
alleviate this problem, two theoretical models have been proposed
to utilize user characteristics maintained in a form of a user
profile.
Although the idea of integrating user profiles into an IR system
is intuitively appealing, and the models seem viable, no research
to date has established a foundation on the roles of user profiles
in such a system. Aiming at the investigation of the roles of user
profiles, therefore, this study first identifies and extends
various query/profile interaction models to provide a ground on
which the investigation can be undertaken. From a continuum of
models characterized based on interaction types, metrics, and
parameters, nearly 400 models are chosen to investigate the "model
space."
Following the preparatory work, a series of experiments are
conducted using an experimental IR system built for this study. In
recognition that existing measures are not sufficient for the
evaluation of so many models, new measures are developed based on
the notion of user satisfaction/frustration. In addition, three
different criteria are introduced to guide users in making
judgements on the quality of retrieved items.
A number of interesting results are produced through the analysis
of the data obtained from the experiments. It is first shown that,
regardless of a criterion or a metric used, there are always some
query/profile interaction models that outperform the query alone
model. In addition, preferable characteristics for different
criteria are identified in terms of interaction types, parameters,
and metrics. To ensure the significance of the results, three
statistical tests are used for different purposes.
AN This item is not available from University Microfilms International
ADG05-61333.
AU CHEN, JASON S. J.
IN University of Southern California Ph.D 1987.
TI DISTRIBUTED QUERY OPTIMIZATION IN FRAGMENTED DATABASE SYSTEMS.
SO DAI V48(09), SecB.
DE Engineering, Electronics and Electrical.
AB Join is the most critical operation in distributed query
optimization. In this thesis, the problem of optimizing multiple
joins in fragmented database systems on both broadcast and
nonbroadcast type computer networks is analyzed. Semantic
information associated with fragments are used to eliminate
unnecessary processing. Data redundancy is considered.
Furthermore, we allow more than one physical copy of a fragment to
be used in a strategy to achieve more parallelism.
In our proposed approach, the problem of optimizing multiple joins
is decomposed into two subproblems: the problem of finding a good
join sequence and the problem of optimizing each two-way join in
the sequence. A dynamic programming algorithm is developed for
determining a join sequence. During intermediate steps of the join
sequence, we have the join results remaining fragmented to achieve
more parallelism and allow more local executions. All the partial
results are assembled at the last two-way join.
If the network has broadcast capability, graph models are
introduced to represent two-way joins. The two-way join
optimization problems are mapped into equivalent graph
minimum-weight vertex cover problems. An algorithm based on
network flow is developed for optimizing two-way joins with
results fragmented. The two-way join optimization problem with
results assembled is proved to be NP-hard. For nonbroadcast
network environments, the problem of optimizing two-way joins
either with results fragmented or with results assembled is also
proved to be NP-hard.
For those NP-hard optimization problems, properties are identified
to reduce the solution search space. Efficient heuristic
procedures based on the identified properties are developed for
suboptimal solutions. Theoretical bounds are provided to ensure
the heuristic solutions are within a certain range from the
optimal solutions.
Semijoins are also included in our approach. A new operation
called domain-specific semijoin is introduced which can be
performed in a fragment-to-fragment manner as opposed to a
relation-to-relation or relation-to-fragment manner as in the
application of regular semijoins. For a given query, there is
always a strategy, using both domain-specific semijoins and
semijoins, which is at least as good as the best strategy with
only semijoins. (Copies available exclusively from Micrographics
Department, Doheny Library, USC, Los Angeles, CA 90089-0182.).
AN University Microfilms Order Number ADG87-27824.
AU CHEN, ZI-TAN.
IN University of California, Santa Barbara Ph.D 1987, 156 pages.
TI QUADTREES AND QUADTREE SPATIAL SPECTRA IN LARGE SCALE GEOGRAPHIC
INFORMATION SYSTEMS--THE HIERARCHICAL HANDLING OF SPATIAL DATA.
SO DAI V48(09), SecB, pp2768.
DE Geotechnology.
AB The demand to manipulate large volumes of geographic data is
growing. Besides conventional maps and statistics, huge volumes of
geographic data are produced by remote sensing, conventional
mapping, and auto-cartographic processes. Such data need to be
manipulated efficiently in very large scale geographic information
systems. However, current geographic information systems exhibit
major shortcomings in the efficient handling of spatial data. The
purpose of this dissertation is to explore the use of quadtrees
and quadtree spatial spectra to improve spatial data handling
efficiency.
Artificial intelligence has a potential to eliminate some of the
disadvantages of present spatial data handling methods. However,
the gap between the theory of AI and its practical application in
spatial data handling is still very wide. Many previous efforts in
this area, including contextual and syntactic analysis in digital
image processing, have shown interesting functions, but also have
serious limitations for applications involving very large spatial
data files.
This study is an effort to shorten this gap by presenting several
related studies at different levels. (1) At a high control level,
a spatial heuristic search module is proposed. It achieves a
significant gain in CPU time efficiency by using spatial knowledge
at an early stage to find a short cut strategy. A heuristic search
substitutes for the blind search of most current geographic
information systems. (2) At the data structure level, quadtrees
are used to represent very large volumes of geographic data,
including both binary and gray tone images. Finally, (3) A global
quadtree coordinate system is proposed for uniform data
representation among different geographic information systems that
have various sizes and locations.
An approximate spatial distribution knowledge--quadtree spatial
spectra (QTSS)--is proposed. It provides the necessary spatial
knowledge for a spatial heuristic search module. Quadtree spatial
spectra contain rich spatial distribution information over a wide
spatial wavelength domain. The speed of generating QTSS is two
orders of magnitude faster than the generating Fast Fourier
Transform (FFT), and its storage form is very compact.
Combining these studies, a practical geographic information system
has been designed. Real geographic data sets are tested. Their
results are analyzed, and compared with current systems.
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END OF IRList Digest
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