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Databases and Information Systems

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1999

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Articles 1 - 30 of 42

Full-Text Articles in Physical Sciences and Mathematics

Characterizations Of Classes Of Programs By Three-Valued Operators, Anthony K. Seda, Pascal Hitzler Dec 1999

Characterizations Of Classes Of Programs By Three-Valued Operators, Anthony K. Seda, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Several important classes of normal logic programs, including the classes of acyclic, acceptable, and locally hierarchical programs, have the property that every program in the class has a unique two-valued supported model. In this paper, we call such classes unique supported model classes. We analyse and characterize these classes by means of operators on three-valued logics. Our studies will motivate the definition of a larger unique supported model class which we call the class of Phi-accessible programs. Finally, we show that the class of Phi -accessible programs is computationally adequate in that every partial recursive function can be implemented by …


On-Line Bayesian Tree-Structured Transformation Of Hidden Markov Models For Speaker Adaptation, Shaojun Wang, Yunxin Zhao Dec 1999

On-Line Bayesian Tree-Structured Transformation Of Hidden Markov Models For Speaker Adaptation, Shaojun Wang, Yunxin Zhao

Kno.e.sis Publications

This paper presents a new recursive Bayesian learning approach for transformation parameter estimation in speaker adaptation. Our goal is to incrementally transform (or adapt) the entire set of HMM parameters for a new speaker or new acoustic enviroment from a small amount of adaptation data. By establishing a clustering tree of HMM Gaussian mixture components, the finest affine transformation parameters for individual HMM Gaussian mixture components can be dynamically searched. The on-line Bayesian learning technique proposed in our recent work is used for recursive maximum a posteriori estimation of affine transformation parameters. Speaker adaptation experiments using a 26-letter English alphabet …


Zbroker: A Query Routing Broker For Z39.50 Databases, Yong Lin, Jian Xu, Ee Peng Lim, Wee-Keong Ng Nov 1999

Zbroker: A Query Routing Broker For Z39.50 Databases, Yong Lin, Jian Xu, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

A query routing broker is a software agent that determines from a large set of accessing information sources the ones most relevant to a user's information need. As the number of information sources on the Internet increases dramatically, future users will have to rely on query routing brokers to decide a small number of information sources to query without incurring too much query processing overheads. In this paper, we describe a query routing broker known as ZBroker developed for bibliographic database servers that support the Z39.50 protocol. ZBroker samples the content of each bibliographic database by using training queries and …


Efficient Support For Decision Flows In E-Commerce Applications, Richard Hull, Francois Llirbat, Jianwen Su, Guozhu Dong, Bharat Kumar, Gang Zhou Oct 1999

Efficient Support For Decision Flows In E-Commerce Applications, Richard Hull, Francois Llirbat, Jianwen Su, Guozhu Dong, Bharat Kumar, Gang Zhou

Kno.e.sis Publications

In the coming era of segment-of-one marketing, decisions about business transactions will be quite intricate, so that customer treatments can be highly individualized, reflecting customer preferences, targeted business objectives, etc. This paper describes a paradigm called “decision flows” for specifying a form of incremental decision-making that can combine a myriad of diverse business factors and be executed in near-realtime. Starting with initial input, a decision flow will iteratively gather and derive additional information until a conclusion is reached. Decision flows can be specified in a rules-based manner that generalizes so-called “business rules” but provides more structure than traditional expert systems. …


Critical It Role In Healthcare: National Agenda, Applications, And Technologies, Jack Corley, Warren Karp, Amit P. Sheth Oct 1999

Critical It Role In Healthcare: National Agenda, Applications, And Technologies, Jack Corley, Warren Karp, Amit P. Sheth

Kno.e.sis Publications

We share a widely-held vision that tomorrow's health care will be delivered by a distributed team using a knowledge based process that is focused on prevention and wellness. Caregivers will be able to treat and monitor patients where and when needed, capturing data as a natural byproduct of care delivery. Clinical teams with a wide range of skills and expertise will deliver consistent, quality care based on timely, situation-specific knowledge and guidance derived from outcomes evidence. That same knowledge will support advances in healthcare research and education. Home care and remote medicine will increase, reducing the need for high-cost hospitalization. …


Research Issues In Web Data Mining, Sanjay Kumar Madria, Sourav S. Bhowmick, Wee-Keong Ng, Ee Peng Lim Sep 1999

Research Issues In Web Data Mining, Sanjay Kumar Madria, Sourav S. Bhowmick, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we discuss mining with respect to web data referred here as web data mining. In particular, our focus is on web data mining research in context of our web warehousing project called WHOWEDA (Warehouse of Web Data). We have categorized web data mining into threes areas; web content mining, web structure mining and web usage mining. We have highlighted and discussed various research issues involved in each of these web data mining category. We believe that web data mining will be the topic of exploratory research in near future.


Non-Repudiation In An Agent-Based E-Commerce System, Chin Chuan Liew, Wee-Keong Ng, Ee Peng Lim, Beng Suang Tan, Kok-Leong Ong Sep 1999

Non-Repudiation In An Agent-Based E-Commerce System, Chin Chuan Liew, Wee-Keong Ng, Ee Peng Lim, Beng Suang Tan, Kok-Leong Ong

Research Collection School Of Computing and Information Systems

Abecos is an agent-based e-commerce system under development at the Nanyang Technological University. A key factor in making this system usable in practice is strict security controls. One aspect of security is the provision of non-repudiation services. As protocols for non-repudiation have focused on -message non-repudiation, its adaptation to afford non-repudiation in a communication session for two agents in Abecos is inefficient. In this work, we investigate and propose a protocol for enforcing non-repudiation in a session. The protocol is believed to be applicable in any e-commerce system; agent- or not agent-based.


Wedagen: A Synthetic Web Database Generator, Pallavi Priyardarshini, Fengqiong Qin, Ee Peng Lim, Wee-Keong Ng Sep 1999

Wedagen: A Synthetic Web Database Generator, Pallavi Priyardarshini, Fengqiong Qin, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

At the Centre for Advanced Information Systems (CAIS), a Web warehousing system is being developed to store and manipulate Web information. The system named WHOWEDA (WareHouse Of WEb DAta) stores extracted Web information as Web tables and provides several Web operators, eg. Web join, Web select, global coupling, etc., to manipulate Web tables. During the implementation of WHOWEDA, it is necessary to perform systematic testing on the system and to evaluate its system performance. While it is possible for WHOWEDA to be tested or evaluated using actual Web pages downloaded from WWW, the amount of time required for such testing …


Locating Web Information Using Web Checkpoints, Aik Kee Luah, Wee-Keong Ng, Ee Peng Lim, Wee Peng Lee, Yinyan Cao Sep 1999

Locating Web Information Using Web Checkpoints, Aik Kee Luah, Wee-Keong Ng, Ee Peng Lim, Wee Peng Lee, Yinyan Cao

Research Collection School Of Computing and Information Systems

Conventional search engines locate information by letting users establish a single web checkpoint1. By specifying one or more keywords, users direct search engines to return a set of documents that contain those keywords. From the documents (links) returned by search engines, user proceed to further probe the WWW from there. Hence, these initial set of documents (contingent upon the occurrence of keyword(s)) serve as a web checkpoint. Generally, these links are numerous and may not result in much fruitful searches. By establishing multiple web checkpoints, a richer and controllable search procedure can be constructed to obtain more relevant Web information. …


Cluster-Based Database Selection Techniques For Routing Bibliographic Queries, Jian Xu, Ee Peng Lim, Wee-Keong Ng Aug 1999

Cluster-Based Database Selection Techniques For Routing Bibliographic Queries, Jian Xu, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

In this paper, we focus on the database selection problem in the context of a global digital library consisting of a large number of online bibliographic servers. Each server hosts a bibliographic database that contains bibliographic records each of which consists of text values for a number of pre-defined bibliographic attributes such as title, author, call number, subject, etc.. Each bibliographic database supports user queries on the bibliographic attributes. Since bibliographic records are relatively small in size, we only consider bibliographic databases that support boolean queries on the bibliographic attributes, and the query results are not ranked. While focusing on …


A Multilevel Secure Workflow Management System, Myong H. Kang, Judith N. Froscher, Amit P. Sheth, Krzysztof J. Kochut, John A. Miller Jun 1999

A Multilevel Secure Workflow Management System, Myong H. Kang, Judith N. Froscher, Amit P. Sheth, Krzysztof J. Kochut, John A. Miller

Kno.e.sis Publications

The Department of Defense (DoD) needs multilevel secure (MLS) workflow management systems to enable globally distributed users and applications to cooperate across classification levels to achieve mission critical goals. An MLS workflow management system that allows a user to program multilevel mission logic, to securely coordinate widely distributed tasks, and to monitor the progress of the workflow across classification levels is required. In this paper, we present a roadmap for implementing MLS workflows and focus on a workflow builder that is a graphical design tool for specifying such workflows.


Considerations For An Effective Telecommunications-Use Policy, Michael E. Whitman, Anthony M. Townsend, Robert J. Aalberts Jun 1999

Considerations For An Effective Telecommunications-Use Policy, Michael E. Whitman, Anthony M. Townsend, Robert J. Aalberts

Faculty and Research Publications

Recent changes in federal telecommunications legislation have underscored the importance of an up-to-date and effective telecommunications-use policy in business organizations. With the proliferation of the Internet, intranets, and email as commonplace business tools, the potential for misuse and subsequent liability has become an increasing concern. Even though the recent Supreme Court decision struck down the obscenity provisions of the Communications Decency Act (CDA), it left intact legislation that effectively mandates development of a sound telecommunications-use policy. In addition to potential liability for systems misuse, organizations have also had to address issues of individual employee privacy within the new systems.

This …


How Proteins Fold, Flex, And Bind Other Molecules, Leslie A. Kuhn, Volker Schnecke, Michael L. Raymer, Paul C. Sanschagrin Apr 1999

How Proteins Fold, Flex, And Bind Other Molecules, Leslie A. Kuhn, Volker Schnecke, Michael L. Raymer, Paul C. Sanschagrin

Kno.e.sis Publications

No abstract provided.


Pi-Web Join In A Web Warehouse, Sourav S. Bhowmick, Sanjay Kumar Madria, Wee-Keong Ng, Ee Peng Lim Apr 1999

Pi-Web Join In A Web Warehouse, Sourav S. Bhowmick, Sanjay Kumar Madria, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the enormous amount of data stored in the World Wide Web, it is increasingly important to design and develop powerful web warehousing tools. The key objective of our web warehousing project, called WHOWEDA (Warehouse of Web Data), is to design and implement a web warehouse that materializes and manages useful information from the Web. In this paper, we introduce the concept of Pi-web join in the context of WHOWEDA. Pi-web join operator is a web information manipulation operator to combine relevant web information residing in two web tables. Informally, it is the combination of web join and web project …


Data Integration By Describing Sources With Constraint Databases, Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su Mar 1999

Data Integration By Describing Sources With Constraint Databases, Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su

Kno.e.sis Publications

We develop a data integration approach for the efficient evaluation of queries over autonomous source databases. The approach is based on some novel applications and extensions of constraint database techniques. We assume the existence of a global database schema. The contents of each data source are described using a set of constraint tuples over the global schema; each such tuple indicates possible contributions from the source. The “source description catalog” (SDC) of a global relation consists of its associated constraint tuples. Such a method of description is advantageous since it is flexible to add new sources and to modify existing …


Efficient Mining Of Partial Periodic Patterns In Time Series Database, Jiawei Han, Guozhu Dong, Yiwen Yin Mar 1999

Efficient Mining Of Partial Periodic Patterns In Time Series Database, Jiawei Han, Guozhu Dong, Yiwen Yin

Kno.e.sis Publications

Partial periodicity search, i.e., search for partial periodic patterns in time-series databases, is an interesting data mining problem. Previous studies on periodicity search mainly consider finding full periodic patterns, where every point in time contributes (precisely or approximately) to the periodicity. However, partial periodicity is very common in practice since it is more likely that only some of the time episodes may exhibit periodic patterns.

We present several algorithms for efficient mining of partial periodic patterns, by exploring some interesting properties related to partial periodicity, such as the Apriori property and the max-subpattern hit set property, and by shared mining …


Prestructuring Neural Networks Via Extended Dependency Analysis With Application To Pattern Classification, George G. Lendaris, Thaddeus T. Shannon, Martin Zwick Mar 1999

Prestructuring Neural Networks Via Extended Dependency Analysis With Application To Pattern Classification, George G. Lendaris, Thaddeus T. Shannon, Martin Zwick

Systems Science Faculty Publications and Presentations

We consider the problem of matching domain-specific statistical structure to neural-network (NN) architecture. In past work we have considered this problem in the function approximation context; here we consider the pattern classification context. General Systems Methodology tools for finding problem-domain structure suffer exponential scaling of computation with respect to the number of variables considered. Therefore we introduce the use of Extended Dependency Analysis (EDA), which scales only polynomially in the number of variables, for the desired analysis. Based on EDA, we demonstrate a number of NN pre-structuring techniques applicable for building neural classifiers. An example is provided in which EDA …


Resource Scheduling In A High-Performance Multimedia Server, Hwee Hwa Pang, Bobby Jose, M. S. Krishnan Mar 1999

Resource Scheduling In A High-Performance Multimedia Server, Hwee Hwa Pang, Bobby Jose, M. S. Krishnan

Research Collection School Of Computing and Information Systems

Supporting continuous media data-such as video and audio-imposes stringent demands on the retrieval performance of a multimedia server. In this paper, we propose and evaluate a set of data placement and retrieval algorithms to exploit the full capacity of the disks in a multimedia server. The data placement algorithm declusters every object over all of the disks in the server-using a time-based declustering unit-with the aim of balancing the disk load. As for runtime retrieval, the quintessence of the algorithm is to give each disk advance notification of the blocks that have to be fetched in the impending time periods, …


Dynamic Service Matchmaking Among Agents In Open Information Environments, Katia Sycara, Matthias Klusch, Seth Widoff, Jianguo Lu Jan 1999

Dynamic Service Matchmaking Among Agents In Open Information Environments, Katia Sycara, Matthias Klusch, Seth Widoff, Jianguo Lu

Computer Science Publications

No abstract provided.


Multivalued Mappings, Fixed-Point Theorems And Disjunctive Databases, Pascal Hitzler, Anthony K. Seda Jan 1999

Multivalued Mappings, Fixed-Point Theorems And Disjunctive Databases, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

In this paper, we discuss the semantics of disjunctive programs and databases and show how multivalued mappings and their fixed points arise naturally within this context. A number of fixed-point theorems for multivalued mappings are considered, some of which are already known and some of which are new. The notion of a normal derivative of a disjunctive program is introduced. Normal derivatives are normal logic programs which are determined by the disjunctive program. Thus, the well-known single-step operator associated with a normal derivative is single-valued, and its fixed points can be found by well-established means. It is shown how fixed …


Search For Charged Higgs Bosons In E+E- Collisions At √S = 181-184 Gev, Barate, R.; Et Al., M. Thulasidas Jan 1999

Search For Charged Higgs Bosons In E+E- Collisions At √S = 181-184 Gev, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Determination Of The Lep Centre-Of-Mass Energy From Zγ Events, R. Barate, Manoj Thulasidas Jan 1999

Determination Of The Lep Centre-Of-Mass Energy From Zγ Events, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A study of events with photons and missing energy has been performed with the data sample obtained with the ALEPH detector at centre-of-mass energies from 161 to 184 GeV, corresponding to a total integrated luminosity of about 80 pb−1. The measured distributions are in agreement with Standard Model predictions, leading to constraints on WWγ gauge coupling parameters ∆κγ and λγ. The results from the fit to the cross sections and to the energy and angular distributions of the photons are: ∆κγ = 0.05+1.15 −1.10(stat)±0.25(syst) λγ = −0.05+1.55 −1.45(stat)±0.30(syst).


Measurement Of The Hadronic Photon Structure Function At Lep 1 For 〈Q2〉 Values Between 9.9 And 284 Gev2, Barate, R.; Et Al., M. Thulasidas Jan 1999

Measurement Of The Hadronic Photon Structure Function At Lep 1 For 〈Q2〉 Values Between 9.9 And 284 Gev2, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Inclusive γ∗γ interactions to hadronic final states where one scattered electron or positron is detected in the electromagnetic calorimeters have been studied in the LEP 1 data taken by ALEPH from 1991 to 1995. The event sample has been used to measure the hadronic structure function of the photon F2γ in three bins with 〈Q2〉 of 9.9, 20.7 and 284 GeV2.


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.


The Nature And Structure Of Impediments To Edi Adoption And Integration: A Survey Of Small- And Medium-Sized Enterprises, Deepak Khazanchi Jan 1999

The Nature And Structure Of Impediments To Edi Adoption And Integration: A Survey Of Small- And Medium-Sized Enterprises, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Electronic data interchange (EDI) is a key enabling component of business-to-business electronic commerce. As firms adopt and integrate advanced information technologies such as EDI, it is important to understand the nature of challenges faced by them. This becomes especially important given the fact that nearly 99.7% of all businesses in the US can be classified as small- to medium-sized enterprises (SMEs). As costs and risks associated with implementing new information technologies decrease, these firms will surely need to focus their attention on managing impediments associated with new technology implementation and learn from the failures or successes of their peer. Consequently, …


Customizable And Ontology-Enhanced Medical Information Retrieval Interfaces, Gondy Leroy, K.M. Tolle, Hsinchun Chen Jan 1999

Customizable And Ontology-Enhanced Medical Information Retrieval Interfaces, Gondy Leroy, K.M. Tolle, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper as an aid to providing synonyms and semantically related concepts to improve searching. All terms are related to the userquery and fit into the query context. The system is unique because its five components combine humancreated and computer-generated elements. The Arizona Noun Phraser extracts phrases from natural language user queries. WordNet and the UMLS Metathesaurus provide synonyms. The Arizona Concept Space generates conceptually related terms. Semantic relationships between queries and concepts are established using the UMLS Semantic Net. Two user studies conducted to evaluate the system are described.


Monitoring The Stability Of The Aleph Vertex Detector, G. Sguazzoni, Manoj Thulasidas Jan 1999

Monitoring The Stability Of The Aleph Vertex Detector, G. Sguazzoni, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements. In particular, the laser system has been used to monitor short-term temperature-related effects and long-term movements. These results and a description of the laser-based alignment correction applied to the 1998 data are presented.


Search For Charginos And Neutralinos In E+E- Collisions At Centre-Of-Mass Energies Near 183 Gev And Constraints On The Mssm Parameter Space, R. Barate, M. Thulasidas Jan 1999

Search For Charginos And Neutralinos In E+E- Collisions At Centre-Of-Mass Energies Near 183 Gev And Constraints On The Mssm Parameter Space, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for charginos and neutralinos are performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies near 183 GeV. In these searches, it is assumed that R-parity is conserved and that the lightest neutralino is the LSP. No evidence of a signal is observed in the 57 pb−1−1 accumulated, which excludes chargino and associated neutralino production up to the kinematic limit over large regions of the MSSM parameter space. Under the assumptions of common gaugino and common sfermion masses at the unification scale, the interplay between the chargino, neutralino and slepton exclusion limits allows a lower …