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Full-Text Articles in Databases and Information Systems

Maintaining Transitive Closure Of Graphs In Sql, Guozhu Dong, Leonid Libkin, Jianwen Su, Limsoon Wong Jan 1999

Maintaining Transitive Closure Of Graphs In Sql, Guozhu Dong, Leonid Libkin, Jianwen Su, Limsoon Wong

Kno.e.sis Publications

It is common knowledge that relational calculus and even SQL are not expressive enough to express recursive queries such as the transitive closure. In a real database system, one can overcome this problem by storing a graph together with its transitive closure and maintaining the latter whenever updates to the former occur. This leads to the concept of an incremental evaluation system, or IES.

Much is already known about the theory of IES but very little has been translated into practice. The purpose of this paper is to fill in this gap by providing a gentle introduction to and …


Infoharness: Managing Distributed, Heterogeneous Information, Kshitij Shah, Amit P. Sheth Jan 1999

Infoharness: Managing Distributed, Heterogeneous Information, Kshitij Shah, Amit P. Sheth

Kno.e.sis Publications

Today, important information is scattered in so many places, formats, and media, that getting the right information at the right time and place is an extremely difficult task. Developing a single software product, for example, includes the creation of documents ranging from the requirements specification and project schedules to marketing presentations, multimedia tutorials, and more. Each document may be created by a different person using a different tool, and each may be stored in a different place. InfoHarness is an information integration system, platform, and tool set that addresses these problems, managing huge amounts of heterogeneous information in a distributed …


Processes Driving The Networked Economy, Amit P. Sheth, Will Van Der Aalst, I. Budak Arpinar Jan 1999

Processes Driving The Networked Economy, Amit P. Sheth, Will Van Der Aalst, I. Budak Arpinar

Kno.e.sis Publications

The authors propose that an organic workflow-process technology will power the evolution of information system architectures. The authors outline three likely stages of architectural evolution in the context of a networked economy and discuss critical gaps in the current technology with respect to their envisioned future.


Web-Based Interlibrary Loan System, Ee Peng Lim, Schubert Foo, Cheng Hai Tan, Kwang-Yong Tan Jan 1999

Web-Based Interlibrary Loan System, Ee Peng Lim, Schubert Foo, Cheng Hai Tan, Kwang-Yong Tan

Research Collection School Of Computing and Information Systems

Interlibrary loan (ILL) system is one of the important library services provided by most public libraries. Through ILL, public libraries share their collections of reading material and library users are able to access library resources beyond their affiliated libraries. However, the present manual ILL process is inconvenient, inefficient and error-prone. In this project, we developed a system that automated many tedious procedures in the existing ILL system. The new ILL system is realized by a number of Java applets customized for librarians and library users. The new ILL system allows library users to submit ILL requests at any time using …


Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay Oct 1998

Validation Of Waimss Incident Duration Estimation Model, Wei Wu, Pushkin Kachroo, Kaan Ozbay

Electrical & Computer Engineering Faculty Research

This paper presents an effort to validate the traffic incident duration estimation model of WAIMSS (wide area incident management support system). Duration estimation model of WAIMSS predicts the incident duration based on an estimation tree which was calibrated using incident data collected in Northern Virginia. Due to the limited sample size, a full scale test of the distribution, mean and variance of incident duration was performed only for the root node of the estimation tree, white only mean tests were executed at all other nodes whenever a data subset was available. Further studies were also conducted on the model error …


Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo Oct 1998

Wide-Area Incident Management System On The Internet, Kaan Ozbay, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

The incident management process consists of four sequential steps-incident detection, response, clearance and recovery. Each of these components comprises of a number of operations and coordinated decision-making between the agencies involved. The provision of computer based support tools for the personnel involved will help develop appropriate strategies and increase efficiency and expediency. Existing systems are developed on various traditional computing platforms. However, with the advent of World Wide Web and Internet based programming tools such as Java, it is now possible to develop platform independent decision support tools for the incident management agencies. Any agency will be able to use …


Logical Information Modeling Of Web-Accessible Heterogeneous Digital Assets, Kshitij Shah, Amit P. Sheth Apr 1998

Logical Information Modeling Of Web-Accessible Heterogeneous Digital Assets, Kshitij Shah, Amit P. Sheth

Kno.e.sis Publications

This paper introduces the MREF framework for representing and correlating information at a higher semantic level than is possible with Web-based information systems today. The role that metadata plays in this framework is described, together with a metadata based infrastructure to support our media independent information correlation paradigm. To keep it consistent with evolving standards, broader acceptance and ease of implementation, MREF abstraction is structured on top of RDF and XML. Its central role in the context of the InfoQuilt system, for exploiting heterogeneous digital media using a federated and scalable architecture, is briefly described.


Trends. Injustice Through Justice Within The Ins And The Fbi: Fertile Territory For Information, Ibpp Editor Mar 1998

Trends. Injustice Through Justice Within The Ins And The Fbi: Fertile Territory For Information, Ibpp Editor

International Bulletin of Political Psychology

The author discusses the quest for justice, in which policymakers, legislators, and those who seek to influence them sometimes seek to effect mandatory sequences of adjudicative procedure upon allegations of misbehavior.


Zebra Image Access System, Srilekha Mudumbai, Kshitij Shah, Amit P. Sheth, Krishnan Parasuraman, Clemens Bertram Feb 1998

Zebra Image Access System, Srilekha Mudumbai, Kshitij Shah, Amit P. Sheth, Krishnan Parasuraman, Clemens Bertram

Kno.e.sis Publications

The ZEBRA system, which is part of the VisualHarness platform for managing heterogeneous data, supports three types of access to distributed image repositories: keyword based, attribute based, and image content based. A user can assign different weights (relative importance) to each of the three types, and within the last type of access, to each of the image properties. The image based access component (IBAC) supports access based on computable image properties such as those based on spatial domain, frequency domain or statistical and structural analysis. However, it uses a novel black box approach of utilizing a Visual Information Retrieval (VIR) …


Strictly Level-Decreasing Logic Programs, Pascal Hitzler, Anthony K. Seda Jan 1998

Strictly Level-Decreasing Logic Programs, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

We study strictly level-decreasing logic programs (sld-programs) as defined earlier by the present authors. It will be seen that sld-programs, unlike most other classes of logic programs, have both a highly intuitive declarative semantics, given as a unique supported model, and are computationally adequate in the sense that every partial recursive function can be represented by some sld-program P. Allowing for a safe use of cuts, an interpreter based on SLDNF-resolution, as implemented for example in standard Prolog systems, is shown to be sound and complete with respect to this class of programs. Furthermore, we study connections between topological …


Interestingness Of Discovered Association Rules In Terms Of Neighborhood-Based Unexpectedness, Guozhu Dong, Jinyan Li Jan 1998

Interestingness Of Discovered Association Rules In Terms Of Neighborhood-Based Unexpectedness, Guozhu Dong, Jinyan Li

Kno.e.sis Publications

One of the central problems in knowledge discovery is the development of good measures of interestingness of discovered patterns. With such measures, a user needs to manually examine only the more interesting rules, instead of each of a large number of mined rules. Previous proposals of such measures include rule templates, minimal rule cover, actionability, and unexpectedness in the statistical sense or against user beliefs.

In this paper we will introduce neighborhood-based interestingness by considering unexpectedness in terms of neighborhood-based parameters. We first present some novel notions of distance between rules and of neighborhood of rules. The neighborhood-based interestingness of …


An Integrated Web-Based Ill System For Singapore Libraries, Schubert Foo, Ee Peng Lim Jan 1998

An Integrated Web-Based Ill System For Singapore Libraries, Schubert Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The paper proposes an integrated Web-based inter-library loan (ILL) system to replace and enhance the existing manual-based ILL system used by Singapore libraries. It describes the system requirements that must be supported in order to make it a viable and acceptable solution to all participating libraries. Subsequently, it presents the client-server Web-based system architecture, database design and Java development platform that are used to implement the system. The new system exhibits a host of advantages over the manual system including the minimising of human resource by eliminating form-filling and other forms of paper work completely, improving the access and speed …


From Contemporary Workflow Process Automation To Adaptive And Dynamic Work Activity Coordination And Collaboration, Amit P. Sheth Sep 1997

From Contemporary Workflow Process Automation To Adaptive And Dynamic Work Activity Coordination And Collaboration, Amit P. Sheth

Kno.e.sis Publications

The article outlines a research agenda for researchers in the area of workflow. We believe that today's workflow systems should evolve to what is termed as work coordination and collaboration systems (WCCSs). A WCCS will: (a) adapt to various changes in the organization (including its interactions with external organizations) and the organizational processes by being able to change the process definitions as well as change the processes and component activities while they are being enacted or executed; and (b) support a unified framework for managing coordination, collaboration, and information based decision making activities that naturally occur as part of organizational …


A Vhdl-93 Hardware Description Browser, Laura C. Debrock, Krishnaprasad Thirunarayan May 1997

A Vhdl-93 Hardware Description Browser, Laura C. Debrock, Krishnaprasad Thirunarayan

Kno.e.sis Publications

This paper describes the design and implementation of the VHDL-93 Hardware Description Browser, which is a tool for the intelligent retrieval of information from VHDL designs. The Browser consists of two UNIX processes: a TCL/TK Graphical User Interface and a Prolog search engine. The GUI elicits queries from the user and submits them to the Prolog search engine via a two-way communication pipe. The search engine satisfies queries by traversing a forest of parse trees corresponding to the associated VHDL designs. The results are then sent to the GUI for posting.

Two public-domain tools were used to implement the Browser: …


The Carnot Heterogeneous Database Project: Implemented Applications, Munindar Singh, Phil Cannata, Michael N. Huhns, Nigel Jacobs, Tomasz Ksiezyk, Kayliang Ong, Amit P. Sheth, Christine Tomlinson, Darrell Woelk Apr 1997

The Carnot Heterogeneous Database Project: Implemented Applications, Munindar Singh, Phil Cannata, Michael N. Huhns, Nigel Jacobs, Tomasz Ksiezyk, Kayliang Ong, Amit P. Sheth, Christine Tomlinson, Darrell Woelk

Kno.e.sis Publications

The Carnot project was an ambitious research project in heterogeneous databases. It integrated a variety of techniques to address a wide range of problems in achieving interoperation in heterogeneous environments. Here we describe some of the major implemented applications of this project. These applications concern(a) accessing a legacy scientific database, (b) automating a workflow involving legacy systems, (c) cleaning data, and (d) retrieving semantically appropriate information from structured databases in response to text queries. These applications support scientific decision support, business process management, data integrity enhancement, and analytical decision support, respectively. They demonstrate Carnot‘s capabilities for (a) heterogeneous query processing, …


Characterizing A Portable Subset Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing Apr 1997

Characterizing A Portable Subset Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing

Kno.e.sis Publications

Goossens defined a structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include VHDL-93 features such as shared variables and postponed processes that change the underlying semantic model. In the presence of shared variables, nondeterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged. Our specification can serve as a correctness criteria for a VHDL-93 simulator.


Feedback Control Solutions To Network Level User-Equilibrium Real-Time Dynamic Traffic Assignment Problems, Pushkin Kachroo, Kaan Ozbay Apr 1997

Feedback Control Solutions To Network Level User-Equilibrium Real-Time Dynamic Traffic Assignment Problems, Pushkin Kachroo, Kaan Ozbay

Electrical & Computer Engineering Faculty Research

A new method for performing dynamic traffic assignment (DTA) is presented which is applicable in real time, since the solution is based on feedback control. This method employs the design of nonlinear H∞ feedback control systems which is robust to certain class of uncertainties in the system. The solution aims at achieving user equilibrium on alternate routes in a network setting.


Investigating The Use Of Kalman Filtering Approaches For Dynamic Origin-Destination Trip Table Estimation, Pushkin Kachroo, Kaan Ozbay, Arvind Narayanan Apr 1997

Investigating The Use Of Kalman Filtering Approaches For Dynamic Origin-Destination Trip Table Estimation, Pushkin Kachroo, Kaan Ozbay, Arvind Narayanan

Electrical & Computer Engineering Faculty Research

This paper studies the applicability of Kalman filtering approaches for network wide traveler origin-destination estimation from link traffic volumes. The paper evaluates the modeling assumptions of the Kalman filters and examines the implications of such assumptions.


Some Relationships Between Foies And Sigma 1 1 Arity Hierarchies, Guozhu Dong, Limsoon Wong Feb 1997

Some Relationships Between Foies And Sigma 1 1 Arity Hierarchies, Guozhu Dong, Limsoon Wong

Kno.e.sis Publications

No abstract provided.


Structural Issues In Active Rule Systems, James Bailey, Guozhu Dong, Kotagiri Ramamohanarao Jan 1997

Structural Issues In Active Rule Systems, James Bailey, Guozhu Dong, Kotagiri Ramamohanarao

Kno.e.sis Publications

Active database systems enhance the functionality of traditional databases through the use of active rules or ‘triggers’. There is little consensus, though, on what components should be included in a rule system. In this paper, the expressive power of some simple active database rule systems is examined and the effect of choosing different features studied. Four important parameters of variation are presented, namely the rule language, the external query language, the meta rule language and the pending rule structure. We show that each of these is highly influential in determining the expressiveness of the rule system as a whole, and …


An Error Handling Framework For The Orbwork Workflow Enactment Service Of Meteor, Davasish Worah, Amit P. Sheth, Krzysztof J. Kochut, John A. Miller Jan 1997

An Error Handling Framework For The Orbwork Workflow Enactment Service Of Meteor, Davasish Worah, Amit P. Sheth, Krzysztof J. Kochut, John A. Miller

Kno.e.sis Publications

Workflow Management Systems (WFMSs) can be used to re-engineer, streamline, automate, and track organizational processes involving humans and automated information systems. However, the state-of-the-art in workflow technology suffers from a number of limitations that prevent it from being widely used in large-scale mission critical applications. Error handling is one such issue. What makes the task of error handling challenging is the need to deal with errors that appear in various components of a complex distributed application execution environment, including various WFMS components, workflow application tasks of different types, and the heterogeneous computing infrastructure.

In this paper, we discuss a top-down …


The Ohio Gis Network: Stage 2 1996 Investment Fund Grant First Year Progress Report To The Ohio Board Of Regents (Ohio Gis Network), Mark Salling Jan 1997

The Ohio Gis Network: Stage 2 1996 Investment Fund Grant First Year Progress Report To The Ohio Board Of Regents (Ohio Gis Network), Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

The Ohio Geographic Information Systems Network (Ohio GIS-Net) is an innovative consortium of Ohio’s urban and rural universities. The consortium is building a center of excellence where state-of-the-art geographic information systems (GIS) technology is applied to a research agenda that is critical to Ohio's economic development and central to research issues in policy sciences, civil engineering, public administration, economics and the environmental, urban and regional sciences. This cutting edge technology is an essential component of the basic research infrastructure of universities. It is also a critical resource in state and local economic development efforts, building and maintaining public infrastructure, and …


The Ohio Gis Network: Stage 1 1993 Investment Fund Development Grant Progress Report To The Ohio Board Of Regents (Ohio Gis Network), Mark Salling Jan 1997

The Ohio Gis Network: Stage 1 1993 Investment Fund Development Grant Progress Report To The Ohio Board Of Regents (Ohio Gis Network), Mark Salling

All Maxine Goodman Levin School of Urban Affairs Publications

The Ohio Geographic Information Systems Network (Ohio GIS-Net) is an innovative consortium of Ohio’s urban and rural universities. The consortium is building a center of excellence where state-of-the-art geographic information systems (GIS) technology is applied to a research agenda that is critical to Ohio's economic development and central to research issues in policy sciences, civil engineering, public administration, economics and the environmental, urban and regional sciences. This cutting edge technology is an essential component of the basic research infrastructure of universities. It is also a critical resource in state and local economic development efforts, building and maintaining public infrastructure, and …


Algorithms For Adapting Materialised Views In Data Warehouses, Mukesh Mohania, Guozhu Dong Dec 1996

Algorithms For Adapting Materialised Views In Data Warehouses, Mukesh Mohania, Guozhu Dong

Kno.e.sis Publications

In this paper we consider the problem of materialised view adaptation in data warehouses. Materialised views are important in data warehousing where they are used to speed up query processing on large amounts of data. User requirements change over time, which may change the definitions of views dynamically. For such situations, the question arises whether the materialised views should be recomputed from scratch for every change in the definition or they should be obtained by adapting old materialised views. Changes to a view definition may be expensive, if the view is recomputed from scratch. Therefore, it is worthwhile to examine …


On The Portability Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing Oct 1996

On The Portability Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing

Kno.e.sis Publications

Goossens defined a structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include shared variables in VHDL-93 that changes the underlying semantic model. In the presence of shared variables, non-deterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged.


Managing Multiple Information Sources Through Ontologies: Relationship Between Vocabulary Heterogeneity And Loss Of Information, Eduardo Mena, Vipul Kashyap, Arantza Illarramendi, Amit P. Sheth Aug 1996

Managing Multiple Information Sources Through Ontologies: Relationship Between Vocabulary Heterogeneity And Loss Of Information, Eduardo Mena, Vipul Kashyap, Arantza Illarramendi, Amit P. Sheth

Kno.e.sis Publications

The ability to deal with a huge number of independent and heterogeneous repositories is the most critical problem in Global Information Systems. One approach to enable efficient query processing is by utilizing semantic descriptions (organized as ontologies) of such repositories whenever available.

In this context semantic relationships among ontologies can be used Query Processors. Three kind of relationships are considered: synonyms and hypernyms. Using synonyms the semantic of the query is preserved; however, when synonyms are not available and hypernyms or hyponyms are used there exists some loss of information that must be measured.


Libsearch: A Window-Based Frontend To Remote Bibliographic Databases On The Internet, Ee Peng Lim, Soo-Yin Cheng Jul 1996

Libsearch: A Window-Based Frontend To Remote Bibliographic Databases On The Internet, Ee Peng Lim, Soo-Yin Cheng

Research Collection School Of Computing and Information Systems

Over the past several years, a number of wide-area information navigation and discovery tools have been introduced, including WAIS[1], Gopher[2], World-Wide Web[3], etc. In this paper, we describe a graphical query interface to remote bibliographic databases that can be found on the internet. A library query client, called LibSearch, has been designed and implemented using a set of APIs based on Z39.50 protocol standard[4]. Z39.50 is an application-layer protocol within the OSI reference model designed to allow library users to remotely access the bibliographic records in the library systems. As increasing number of OPAC systems are being established as Z39.50 …


Observer: An Approach For Query Processing In Global Information Systems Based On Interoperation Across Pre-Existing Ontologies, Eduardo Mena, Vipul Kashyap, Amit P. Sheth, Arantza Illarramendi Jun 1996

Observer: An Approach For Query Processing In Global Information Systems Based On Interoperation Across Pre-Existing Ontologies, Eduardo Mena, Vipul Kashyap, Amit P. Sheth, Arantza Illarramendi

Kno.e.sis Publications

The huge number of autonomous and heterogeneous data repositories accessible on the “global information infrastructure” makes it impossible for users to be aware of the locations structure/organization, query languages and semantics of the data in various repositories. There is a critical need to complement current browsing, navigational and information retrieval techniques with a strategy that focuses on information content and semantics. In any strategy that focuses on information content, the most critical problem is that of different vocabularies used to describe similar information across domains. We discuss a scalable approach for vocabulary sharing. The objects in the repositories are represented …


Proof Strategies For Hardware Verification, Robert Eastham, Krishnaprasad Thirunarayan May 1996

Proof Strategies For Hardware Verification, Robert Eastham, Krishnaprasad Thirunarayan

Kno.e.sis Publications

Ascertaining correctness of digital hardware designs through simulation does not scale-up for large designs because of the sheer combinatorics of the problem. Formal verification of hardware designs holds promise because its computational complexity is of the order of number of different types of components (and not number of components in the design). This approach requires the specification of the behavior and the design in a formal language, and reason with them using a theorem prover. In this paper we attempt to develop a methodology for writing and using these specifications for some important classes of hardware circuits. We examine digital …


Semantic And Schematic Similarities Between Database Objects: A Context-Based Approach, Vipul Kashyap, Amit P. Sheth Jan 1996

Semantic And Schematic Similarities Between Database Objects: A Context-Based Approach, Vipul Kashyap, Amit P. Sheth

Kno.e.sis Publications

In a multidatabase system, schematic conflicts between two objects are usually of interest only when the objects have some semantic similarity. We use the concept of semantic proximity, which is essentially an abstraction/mapping between the domains of the two objects associated with the context of comparison. An explicit though partial context representation is proposed and the specificity relationship between contexts is defined. The contexts are organized as a meet semi-lattice and associated operations like the greatest lower bound are defined. The context of comparison and the type of abstractions used to relate the two objects form the basis of a …