Databases and Information Systems Commons^™

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 …

Export Database Derivation Approach For Supporting Object-Oriented Wrapper Queries, Ee Peng Lim, Hon-Kuan Lee

Research Collection School Of Computing and Information Systems

Wrappers export the schema and data of existing heterogeneous databases and support queries on them. In the context of cooperative information systems, we present a flexible approach to specify the derivation of object-oriented (OO) export databases from local relational databases. Our export database derivation consists of a set of extent derivation structures (EDS) which defines the extent and deep extent of export classes. Having well-defined semantics, the EDS can be readily used in transforming wrapper queries to local queries. Based on the EDS, we developed a wrapper query evaluation strategy which handles OO queries on the export databases. The strategy …

Four-Fermion Production In E+E- Collisions At Centre-Of-Mass Energies Of 130 And 136 Gev, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

Four-fermion events have been selected in a data sample of 5.8 pb−1 collected with the aleph detector at centre-of-mass energies of 130 and 136 GeV. The final states ℓ+ℓ−qq, ℓ+ℓ−ℓ+ℓ−, ννqq, and ννℓ+ℓ− have been examined. Five events are observed in the data, in agreement with the Standard Model predictions of 6.67±0.38 events from four-fermion processes and 0.14−0.05+0.19 from background processes.

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.

An Evidential Reasoning Approach To Attribute Value Conflict Resolution In Database Integration, Ee Peng Lim, Jaideep Srivastava, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel [1] showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. In this paper, we show that uncertain information can also arise when the database integration process requires information not directly represented in the component databases, but can be obtained through some summary of data. We therefore propose an extended relational model based on Dempster-Shafer theory of evidence [2] to incorporate such uncertain knowledge about the source databases. The extended relation uses evidence sets to represent …

The Design Of A Financial Management Database System, Edward G. Leszynski

Theses and Dissertations

This research led to the design and development of a financial management database system for the Aeronautical Systems Center (AS C) Environmental Management (EM) Systems Program Office (SPO), which has the responsibility of managing the environmental contracts for the Government-Owned, Contractor-Operated (GOCO) plants that are owned by the Air Force. This thesis investigated the various 'development strategies' and 'methodologies' described in the Management Information Systems literature in order to devise an end-user development strategy capable of meeting the EM SPO's requirements. In addition, the information requirements, conceptual design and prototyping, and procedures phases of the System Development Life Cycle (SDLC) …

Measurement Of The B Forward-Backward Asymmetry And Mixing Using High-P⊥ Leptons, Buskulic, D., M. Thulasidas

Research Collection School Of Computing and Information Systems

The B0 - B̄0 average mixing parameter χ and b forward-backward asymmetry AFB0(b) are measured from a sample of about 4 200 000 Z → qq̄ events recorded with the ALEPH detector at LEP in the years 1990–1995. High transverse momentum electrons and muons produced in b semileptonic decays provide the tag of the quark flavour and of its charge.The average mixing parameter and the pole b asymmetry are measured to be χ = 0.1246 ± 0.0051stat ± 0.0052syst, AFB0(b) = 0.1008 ± 0.0043stat ± 0.0028syst. The value of sin2θweff = 0.23198 ± 0.00092 is extracted from the asymmetry measurement.

Mass Limit For The Standard Model Higgs Boson With The Full Lep I Aleph Data Sample, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

The reaction e+e− → HZ∗ is used to search for the standard model Higgs boson in the Hνν and the Hℓ+ℓ− channels. The data sample corresponds to about 4.5 million hadronic Z decays collected by the ALEPH experiment at LEP from 1989 to 1995 at centre-of-mass energies at and around the Z peak. Three candidate events are found in the Hμ+μ− channel, in agreement with the expected background from the electroweak process e+e− ℓ+ℓ−qq. This search results in a 95% C.L. lower limit on the Higgs boson mass of 63.9 GeV/c2.

Observation Of Charmless Hadronic B Decays, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Search For Cp Violation In The Decay Z → B B̄ G, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

About three million hadronic decays of the Z collected by ALEPH in the years 1991 to 1994 are used to search for anomalous CP violation beyond the Standard Model in the decay Z → bb̄g. The study is performed by analyzing angular correlations between the two quarks and the gluon in three-jet events and by measuring the differential two-jet rate. No signal of CP violation is found. For the combinations of anomalous CP violating couplings, ĥb = ĥAbgVh - ĥVbgAb and hb* = √ĥVb2 + ĥAb2, limits of | ĥb | b*

Search For Charginos And Neutralinos With R-Parity Violation At √S = 130 And 136 Gev, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for charginos and neutralinos produced in e +e - collisions at centre-of-mass energies of 130 and 136 GeV have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In the 5.7 pb -1 data sample collected by ALEPH, no candidate events were found. As a result, chargino and neutralino masses and couplings are constrained and the domains previously excluded at LEP1 are extended.

Strange B Baryon Production And Lifetime In Z Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Ξb is performed with a study of Ξ-lepton correlations. Forty-four events with same sign Ξ−ℓ− combinations are found whereas 8.4 are expected based on the rate of opposite sign Ξ−ℓ+ combinations. This significant excess is interpreted as evidence for Ξb semileptonic decays. The measured product branching ratio is Br(b → Ξb) × Br(Ξb→ XcXℓ−νℓ) × Br(Xc→ Ξ−X′) = (5.4±1.1(stat) ± 0.8(syst)) × 10−4 per lepton species, averaged over electrons and muons, with Xc …

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.

On Integrating Existing Bibliographic Databases And Structured Databases, Ying Lu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

It is widely accepted that future digital library applications have to be built upon different kinds of database servers to draw different forms of data from them. These data include bibliographic data, text data, multimedia data, and structured data. We address the problem of integrating existing bibliographic and structured databases which reside at different locations in the network. To integrate bibliographic data and structured data, we extended the well-known SQL model to represent bibliographic related attributes and queries. In particular, we have added a new data type to model attributes in the bibliographic database. We have also designed specialized predicates …

Measurement Of The Mass Of The Λb Baryon, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Concept Hierarchy Memory Model: A Neural Architecture For Conceptual Knowledge Representation, Learning, And Commonsense Reasoning, Ah-Hwee Tan, Hui-Shin Vivien Soon

Research Collection School Of Computing and Information Systems

This article introduces a neural network based cognitive architecture termed Concept Hierarchy Memory Model (CHMM) for conceptual knowledge representation and commonsense reasoning. CHMM is composed of two subnetworks: a Concept Formation Network (CFN), that acquires concepts based on their sensory representations; and a Concept Hierarchy Network (CHN), that encodes hierarchical relationships between concepts. Based on Adaptive Resonance Associative Map (ARAM), a supervised Adaptive Resonance Theory (ART) model, CHMM provides a systematic treatment for concept formation and organization of a concept hierarchy. Specifically, a concept can be learned by sampling activities across multiple sensory fields. By chunking relations between concepts as …

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

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 …

Specifying Object-Oriented Federated Database From Existing Databases, Ee Peng Lim, M. L. Lim, J. Srivastava

Research Collection School Of Computing and Information Systems

In this paper, we present a mapping strategy that is based on a proposed set of DB integration operations. We first define an OO federated DB as a virtual view on multiple OO export DBs. Our DB mapping strategy systematically derives each of the class extents, deep class extents and relationships of the federated DB using an operator tree consisting of the integration operations. This mapping approach differs from the other existing approaches in that it is algebraic based, and is therefore very suitable for implementing federated query processing.

Measurement Of Hadron And Lepton-Pair Production From E+E- Annihilation At Centre-Of-Mass Energies Of 130 And 136 Gev, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Study Of The B0sb0s Oscillation Frequency Using D-S ℓ+ Combinations In Z Decays, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

A lower limit on the oscillation frequency of the B s 0 B s 0 system is obtained from approximately four million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1995. Leptons are combined with opposite sign D s − candidates reconstructed in seven different decay modes as evidence of semileptonic B s 0 decays. Criteria designed to ensure precise proper time reconstruction select 277D s − ℓ + combinations. The initial state of these B s 0 candidates is determined using an algorithm optimized to efficiently utilise the tagging information available for each event. …

Towards Designing A Knowledge-Based Tutoring System : Sql-Tutor As An Example, Gang Zhou

Dissertations

A Knowledge-Based Tutoring System, also sometimes called an Intelligent Tutoring System, is a computer based instructional system that uses artificial intelligence techniques to help people learn some subject. The goal of the system is to provide private tutoring to its students based on their different backgrounds, requests, and interests. The system knows what subject materials it should teach, when and how to teach them, and can diagnose the mistakes made by the students and help them correct the mistakes.

The major objective of this dissertation is to investigate and develop a generic framework upon which we can build a Knowledge-Based …

Pattern Discovery In Sequence Databases : Algorithms And Applications To Dna/Protein Classification, Gung-Wei Chirn

Dissertations

Sequence databases comprise sequence data, which are linear structural descriptions of many natural entities. Approximate pattern discovery in a sequence database can lead to important conclusions or prediction of new phenomena. Traditional database technology is not suitable for accomplishing the task, and new techniques need to be developed.

In this dissertation, we propose several new techniques for discovering patterns in sequence databases. Our techniques incorporate pattern matching algorithms and novel heuristics for discovery and optimization. Experimental results of applying the techniques to both generated data and DNA/proteins show the effectiveness of the proposed techniques.

We then develop several classifiers using …

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 …

The Quest For The Gnarl, Rudy Rucker

SWITCH

The article describes some of the author’s own image-generating computer programs that he describes as “gnarly”. He began writing a simple spirograph program based off simple sine wave function called Spiro. Later transitioned into writing with C and better programs using more nonlinear feedback. Where Spiro is based on a simple sine wave function, Vine uses a nested sine function: the sine of the sine. The need for a more complicated computational approach lead to iteration and parallelism. Julgnarl uses Iteration and Calife uses parallelism. Calife shows one-dimensional cellular automata: spaces in which virtual computers are lined up like beads …

Gnarly Rantings About The Hacker And The Ants, Rudy Rucker

SWITCH

The article is an excerpt from Rucker’s book “The Happy Mutant”. It begins with his reflection of his career with GoMotion. He discusses the relation that he saw between design and cyberspace. Later he discusses his experience with a game a colleague found on the net: a virtual world where player is an ant. He talks about the struggles he goes through in this virtual world because of game difficulty and poor visuals. He ties it all in with how the Silicon Valley works in a similar way, and is filled with hackers and programers all needing each other to …

How I Got Gnarly, Rudy Rucker

SWITCH

The article describes how Rudy Rucker’s curious interest in celluar automata led to his career in mathematical computer science at San José State University. After conducting interviews on the theory of cellular automata as a freelance writer, he felt compelled to be involved in this great intellectual revolution in computer-aided experimental mathematics. Committed to reinventing himself, Rucker's interactions with mathematicians inspired him to write “Mind Tools”, a book that surveys mathematics from the standpoint that is information. After publishing his book, in 1987, he was eventually offered a position at SJSU in the Mathematics and Computer Science department. With assistance …

A System For Structured Management Of Hypermedia Resources For The World Wide Web, Kevin L. Marlowe

Computer Science Theses & Dissertations

The World Wide Web (WWW) is arguably the preferred method for disseminating information across the Internet. Most of the work to support the advancement of WWW technology has focused on servers used in storing and retrieving information, browsers for viewing this information, and editors or filters for creating the information.

One area which has received little attention is that of actually managing this information at the local host. This thesis describes the development of a means for organizing local data prior to its publishing on the WWW, a method for gathering local pages together and preparing them for distribution, and …

A Precise Measurement Of The Average B Hadron Lifetime, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

An improved measurement of the average b hadron lifetime is performed using a sample of 1.5 million hadronic Z decays, collected during the 1991–1993 runs of ALEPH, with the silicon vertex detector fully operational. This uses the three-dimensional impact parameter distribution of lepton tracks coming from semileptonic b decays and yields an average b hadron lifetime of 1.533 ± 0.013 ± 0.022 ps.

Entity Identification In Database Integration, Ee Peng Lim, Jaideep Srivastava, Satya Prabhakar, James Richardson

Research Collection School Of Computing and Information Systems

The objective of entity identification is to determine the correspondence between objective instances from more than one database. This paper examines the problem at the instance level assuming that schema level heterogeneity has been resolved a priori. Soundness and completeness are defined as the desired properties of any entity-identification technique. To achieve soundness, a set of identity and distinctness rules have to be established for the entities in the integrated world. We then propose the use of extended key, which is the union of keys (and possibly other attributes) from the relations to be matched, and its corresponding identity rule …