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Databases and Information Systems

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Research Collection School Of Computing and Information Systems

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2000

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Full-Text Articles in Physical Sciences and Mathematics

Side Collision Warning System For Transit Buses, Sue Mcneil, David Duggins, Christoph Mertz, Arne Suppe, Chuck Thorpe Oct 2000

Side Collision Warning System For Transit Buses, Sue Mcneil, David Duggins, Christoph Mertz, Arne Suppe, Chuck Thorpe

Research Collection School Of Computing and Information Systems

Transit buses are involved in many more accidents than other vehicles. Collision warning systems (CWS) are therefore placed most efficiently on these buses. In our project, we investigate their operating environment and available technologies to develop performance specifications for such CWS. The paper discusses our findings of transit buses driving through very cluttered surroundings and being involved in many different types of accidents where currently available CWS no not work effectively. One of the focuses of our work is pedestrians around the bus and their detection.

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Dtd-Miner: A Tool For Mining Dtds From Xml Documents, Moh Chuang Hue, Ee Peng Lim, Wee-Keong Ng Jun 2000

Dtd-Miner: A Tool For Mining Dtds From Xml Documents, Moh Chuang Hue, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

XML documents are semistructured and the structure of the documents is embedded in the tags. Although XML documents can be accompanied by a DTD that defines the structure of the documents, the presence of a DTD is not mandatory. The difficulty in deriving the DTD for XML documents lies in the fact that DTDs are of different syntax as XML and that prior knowledge of the structure of the documents is required. In this paper, we introduce DTD-Miner, an automatic structure-mining tool for XML documents. Using a Web-based interface, the user will be able to submit a set of similarly …

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Re-Engineering Structures From Web Documents, Moh Chuang Hue, Ee Peng Lim, Wee-Keong Ng Jun 2000

Re-Engineering Structures From Web Documents, Moh Chuang Hue, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

To realize a wide range of applications (including digital libraries) on the Web, a more structured way of accessing the Web is required and such requirement can be facilitated by the use of XML standard. In this paper, we propose a general framework for reverse engineering (or re-engineering) the underlying structures i.e.,the DTD from a collection of similarly structured XML documents when they share some common but unknown DTDs. The essential data structures and algorithms for the DTD generation have been delveloped and experiments on real Web collections have been conducted to demonstrate their feasibilty. In addition, we also proposed …

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Predictive Adaptive Resonance Theory And Knowledge Discovery In Databases, Ah-Hwee Tan, Hui-Shin Vivien Soon May 2000

Predictive Adaptive Resonance Theory And Knowledge Discovery In Databases, Ah-Hwee Tan, Hui-Shin Vivien Soon

Research Collection School Of Computing and Information Systems

This paper investigates the scalability of predictive Adaptive Resonance Theory (ART) networks for knowledge discovery in very large databases. Although predictive ART performs fast and incremental learning, the number of recognition categories or rules that it creates during learning may become substantially large and cause the learning speed to slow down. To tackle this problem, we introduce an on-line algorithm for evaluating and pruning categories during learning. Benchmark experiments on a large scale data set show that on-line pruning has been effective in reducing the number of the recognition categories and the time for convergence. Interestingly, the pruned networks also …

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Load Sharing In Distributed Multimedia-On-Demand Systems, Y. C. Tay, Hwee Hwa Pang May 2000

Load Sharing In Distributed Multimedia-On-Demand Systems, Y. C. Tay, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Service providers have begun to offer multimedia-on-demand services to residential estates by installing isolated, small-scale multimedia servers at individual estates. Such an arrangement allows the service providers to operate without relying on a highspeed, large-capacity metropolitan area network, which is still not available in many countries. Unfortunately, installing isolated servers can incur very high server costs, as each server requires spare bandwidth to cope with fluctuations in user demand. The authors explore the feasibility of linking up several small multimedia servers to a (limited-capacity) network, and allowing servers with idle retrieval bandwidth to help out servers that are temporarily overloaded; …

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A Framework For Acquiring Domain Semantics And Knowledge For Database Integration, Roger Hsiang-Li Chiang, Ee Peng Lim, Veda C. Storey Mar 2000

A Framework For Acquiring Domain Semantics And Knowledge For Database Integration, Roger Hsiang-Li Chiang, Ee Peng Lim, Veda C. Storey

Research Collection School Of Computing and Information Systems

Database integration research has traditionally focused on understanding integration issues from the schema and instance perspectives. As a result, database integration approaches tend to rely on a direct comparison of schema and instance elements. However, when the integration of heterogeneous databases is performed without considering the domain semantics and knowledge of local databases such as context information and requirement specifications, an incorrect integrated database may be produced. In this research, a framework for carrying out database integration tasks using the above knowledge is proposed. The framework provides a thorough foundation to: 1. analyze database integration issues from a broad scope, …

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The Integration Of Relationship Instances From Heterogeneous Databases, Ee Peng Lim, Roger Hsiang-Li Chiang Jan 2000

The Integration Of Relationship Instances From Heterogeneous Databases, Ee Peng Lim, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

In the process of integrating legacy databases, one has to resolve inter-database conflicts at both the schema and instance levels. In this paper, we discuss relationship conflicts as a special type of conflicts to be resolved during the database integration. Relationships are properties that relate real world objects. So far, most inter-database relationship conflicts are addressed at the schema-level by various schema integration techniques. However, instance-level relationship conflicts are largely neglected. This paper therefore investigates the causes of instance-level relationship conflicts and proposes a taxonomy for classifying instance-level relationship conflicts. In addition, we develop a systematic process to resolve instance-level …

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Search For R-Parity Violating Decays Of Supersymmetric Particles In E+E- Collisions At Centre-Of-Mass Energies Near 183 Gev, R. Barate, M. Thulasidas Jan 2000

Search For R-Parity Violating Decays Of Supersymmetric Particles In E+E- Collisions At Centre-Of-Mass Energies Near 183 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for pair-production of supersymmetric particles under the assumption that R-parity is violated via a single dominant LLE¯LLE¯, LQD¯LQD¯ or U¯D¯D¯U¯D¯D¯ coupling are performed using the data collected by the ALEPH collaboration at centre-of-mass energies of 181–184 GeV. The observed candidate events in the data are in agreement with the Standard Model expectations. Upper limits on the production cross-sections and lower limits on the masses of charginos, sleptons, squarks and sneutrinos are derived.

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Study Of Charm Production In Z Decays, R. Barate, M. Thulasidas Jan 2000

Study Of Charm Production In Z Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The production rates of D∗±D∗±, D∗±sDs∗±, D±D±, D0/D¯0D0/D¯0, D±sDs±, and Λ+c/Λ¯−cΛc+/Λ¯c− in Z→cc¯Z→cc¯ decays are measured using the LEP I data sample recorded by the ALEPH detector. The fractional energy spectrum of the D∗±D∗± is well described as the sum of three contributions: charm hadronisation, b hadron decays and gluon splitting into a pair of heavy quarks. The probability for a c quark to hadronise into a D∗+D∗+ is found to be f(c→D∗+)=0.233±0.010(stat.)±0.011(syst.)f(c→D∗+)=0.233±0.010(stat.)±0.011(syst.). The average fraction of the beam energy carried by D∗±D∗± mesons in Z→cc¯Z→cc¯ events is measured to be ⟨XE(D∗±)⟩cc¯=0.4878±0.0046(stat.)±0.0061(syst.).⟨XE(D∗±)⟩cc¯=0.4878±0.0046(stat.)±0.0061(syst.). The D∗±D∗± energy and the hemisphere mass imbalance …

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Study Of Fermion Pair Production In E+E- Collisions At 130-183 Gev, R. Barate, M. Thulasidas Jan 2000

Study Of Fermion Pair Production In E+E- Collisions At 130-183 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The cross sections and forward-backward asymmetries of hadronic and leptonic events produced in e+e−e+e− collisions at centre-of-mass energies from 130 to 183 GeV are presented. Results for e+e−e+e−, μ+μ−μ+μ−, τ+τ−τ+τ−, qq¯qq¯, bb¯bb¯ and cc¯cc¯ production show no significant deviation from the Standard Model predictions. This enables constraints to be set upon physics beyond the Standard Model such as four-fermion contact interactions, leptoquarks, Z′Z′ bosons and R-parity violating squarks and sneutrinos. Limits on the energy scale ΛΛ of e+e−ff¯e+e−ff¯ contact interactions are typically in the range from 2 to 10 TeV. Limits on R-parity violating sneutrinos reach masses of a few …

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An Integrated Data Mining System To Automate Discovery, Cecil Chua, Roger Hsiang-Li Chiang, Ee Peng Lim Jan 2000

An Integrated Data Mining System To Automate Discovery, Cecil Chua, Roger Hsiang-Li Chiang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Many data analysts require tools which can integrate their database management packages (e.g. Microsoft Access) with their data analysis ones (e.g. SAS, SPSS), and provide guidance for the selection of appropriate mining algorithms. In addition, the analysts need to extract and validate statistical results to facilitate data mining. In this paper, we describe an integrated data mining system called the Linear Correlation Discovery System (LCDS) that meets the above requirement. LCDS consists of four major sub-components, two of which, the selection assistant and the statistics coupler, are discussed in this paper. The former examines the schema and instances to determine …

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Inclusive Production Of Π0, Η, Η′ (958), Kg0s And Λ In Two- And Three-Jet Events From Hadronic Z Decays, R. Barate, M. Thulasidas Jan 2000

Inclusive Production Of Π0, Η, Η′ (958), Kg0s And Λ In Two- And Three-Jet Events From Hadronic Z Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The production rates and the inclusive cross sections of the isovector meson π0π0, the isoscalar mesons ηη and η′(958)η′(958), the strange meson K0SKS0 and the ΛΛ baryon have been measured as functions of scaled energy in hadronic events, two-jet events and each jet of three-jet events from hadronic Z decays and compared to Monte Carlo models. The analysis is based on 3.7 million hadronic events collected with the ALEPH detector at LEP at a centre-of-mass energy of s√=91.2s=91.2 GeV. The JETSET modelling of the gluon fragmentation into isoscalar mesons is found to be in agreement with the experimental results. HERWIG …

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Supervised Adaptive Resonance Theory And Rules, Ah-Hwee Tan Jan 2000

Supervised Adaptive Resonance Theory And Rules, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Supervised Adaptive Resonance Theory is a family of neural networks that performs incremental supervised learning of recognition categories (pattern classes) and multidimensional maps of both binary and analog patterns. This chapter highlights that the supervised ART architecture is compatible with IF-THEN rule-based symbolic representation. Specifi­cally, the knowledge learned by a supervised ART system can be readily translated into rules for interpretation. Similarly, a priori domain knowl­edge in the form of IF-THEN rules can be converted into a supervised ART architecture. Not only does initializing networks with prior knowl­edge improve predictive accuracy and learning efficiency, the inserted symbolic knowledge can also …

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Measurement Of The Z Resonance Parameters At Lep, R. Barate, M. Thulasidas Jan 2000

Measurement Of The Z Resonance Parameters At Lep, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The properties of the Z resonance are measured from the analysis of 4.5 million Z decays into fermion pairs collected with the ALEPH detector at LEP. The data are consistent with lepton universality. The resonance parameters are measured to be MZ=(91.1885±0.0031)GeV/c2MZ=(91.1885±0.0031)GeV/c2, ΓZ=(2.4951±0.0043)ΓZ=(2.4951±0.0043) GeV, σ0had=(41.559±0.058)σhad0=(41.559±0.058) nb and, combining the three lepton flavours, Rℓ=20.725±0.039Rℓ=20.725±0.039. The corresponding number of light neutrino species is Nν=2.983±0.013Nν=2.983±0.013 and the strong coupling constant is αs(MZ)=0.114±0.004±0.002QCD+0.005log10[MH150GeV/c2]αs(MZ)=0.114±0.004±0.002QCD+0.005log10⁡[MH150GeV/c2]. The lepton pair forward-backward asymmetry is measured to be A0,ℓFB=0.0173±0.0016AFB0,ℓ=0.0173±0.0016 from which the effective weak mixing angle is derived: sin2θlepteff=0.23089±0.00089sin2⁡θefflept=0.23089±0.00089. The measurement of the leptonic width Γℓℓ=84.02±0.15Γℓℓ=84.02±0.15 MeV leads to a determination …

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Measurements Of The Structure Of Quark And Gluon Jets In Hadronic Z Decays, R. Barate, M. Thulasidas Jan 2000

Measurements Of The Structure Of Quark And Gluon Jets In Hadronic Z Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

An experimental investigation of the structure of identified quark and gluon jets is presented. Observables related to both the global and internal structure of jets are measured; this allows for tests of QCD over a wide range of transverse momentum scales. The observables include distributions of jet-shape variables, the mean and standard deviation of the subjet multiplicity distribution and the fragmentation function for charged particles. The data are compared with predictions of perturbative QCD as well as QCD-based Monte Carlo models. In certain kinematic regions the measurements are sensitive mainly to perturbatively calculable effects, allowing for a test of QCD. …

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