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1998

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Articles 31 - 56 of 56

Full-Text Articles in Databases and Information Systems

A Discourse Subsystem For Information Extraction, Doha Ahmed Ali Shawki Apr 1998

A Discourse Subsystem For Information Extraction, Doha Ahmed Ali Shawki

Archived Theses and Dissertations

No abstract provided.


Resonant Structure And Flavour Tagging In The Bπ± System Using Fully Reconstructed B Decays, Barate, R.; Et Al., M. Thulasidas Apr 1998

Resonant Structure And Flavour Tagging In The Bπ± System Using Fully Reconstructed B Decays, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


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.


Measurement Of Triple Gauge-Boson Couplings At 172 Gev, Barate, R.; Et Al, M. Thulasidas Mar 1998

Measurement Of Triple Gauge-Boson Couplings At 172 Gev, Barate, R.; Et Al, M. Thulasidas

Research Collection School Of Computing and Information Systems

The triple gauge-boson couplings, αWΦ, αW and αBΦ, have been measured using 34 semileptonically and 54 hadronically decaying W+W− candidate events. The events were selected in the data recorded during 1996 with the ALEPH detector at 172 GeV, corresponding to an integrated luminosity of 10.65 pb−1. The triple gauge-boson couplings have been measured using optimal observables constructed from kinematic information of W+W− events. The results are in agreement with the Standard Model expectation.


Measurement Of The W Mass By Direct Reconstruction In E+E- Collisions At 172 Gev, Barate, R.; Et Al., M. Thulasidas Mar 1998

Measurement Of The W Mass By Direct Reconstruction In E+E- Collisions At 172 Gev, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


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) …


Four-Jet Final State Production In E+E- Collisions At Centre-Of-Mass Energies Ranging From 130 To 184 Gev, R. Barate, Manoj Thulasidas Feb 1998

Four-Jet Final State Production In E+E- Collisions At Centre-Of-Mass Energies Ranging From 130 To 184 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The four jet topology is analysed in the ALEPH data taken between November 1995 and October 1997, at centre-of-mass energies ranging from 130 to 184 GeV. While an unexpected accumulation of events with a dijet mass sum around 105 GeV/c 2 had been observed during the first run in 1995 at 130/136 GeV, corresponding to an integrated luminosity of 5.7 pb1 , no significant dierences between data and standard model prediction is seen, either in the high energy runs (81.1 pb1 taken at centre-of-mass energies from 161 to 184 GeV) or in the 7.1 pb1 recorded during a new short …


A Visual Object-Relationship Query Language For User-Database Interaction, Keng Siau Feb 1998

A Visual Object-Relationship Query Language For User-Database Interaction, Keng Siau

Research Collection School Of Computing and Information Systems

User–database interaction has a direct and immediate effect on the effectiveness and efficiency of database end users. Traditional query languages like SQL and QBE require end users to understand the underlying data structure in the database. This is a burden on end users, especially novice end users who have little technical knowledge or understanding of database. To alleviate the need for end users to know the logical database organization, this paper proposes the use of an object–relationship (OR) model and a formal high-level visual query language as the interface. Using this interface, end users communicate only domain knowledge with the …


Applications Of Internet Technology For Requirements Elicitation, Deepak Pandit Jan 1998

Applications Of Internet Technology For Requirements Elicitation, Deepak Pandit

Theses

During the Requirements Elicitation part of a project various stakeholders need to be able to communicate their requirements to the developers, and the developers need to be able communicate their understanding back to the stakeholders. Communication between the various members of the project is the key factor during the Requirements Elicitation part of a project. Easing communications between stakeholders and developers makes the process of eliciting requirement easier, leading to better requirements specification and eventually a better product.

The Requirements Elicitation Process through Internet (REPI) web site has been designed and implemented to explore this idea. The prototype version of …


Measurement Of The Axial-Vector Τ Spectral Functions And Determination Of Αs (M2Τ) From Hadronic Τ Decays, R. Barate, M. Thulasidas Jan 1998

Measurement Of The Axial-Vector Τ Spectral Functions And Determination Of Αs (M2Τ) From Hadronic Τ Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

An analysis based on 124 000 selected ττ pairs recorded by the ALEPH detector at LEP provides the vector (V)(V) and axial-vector (A)(A) spectral functions of hadronic ττ decays together with their total widths. This allows the evaluation of finite energy chiral sum rules that are weighted integrals over the (V−A)(V−A) spectral functions. In addition, a precise measurement of αsαs along with a determination of nonperturbative contributions at the ττ mass scale is performed. The experimentally and theoretically most robust determination of αs(M2τ)αs(Mτ2) is obtained from the (V+A)(V+A) fit that yields αs(M2τ)=0.334±0.022αs(Mτ2)=0.334±0.022 giving αs(M2Z)=0.1202±0.0027αs(MZ2)=0.1202±0.0027 after the extrapolation to the mass …


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 Experimental Study Into The Effect Of Varying The Join Selectivity Factor On The Performance Of Join Methods In Relational Databases, Ada Mallet Jan 1998

An Experimental Study Into The Effect Of Varying The Join Selectivity Factor On The Performance Of Join Methods In Relational Databases, Ada Mallet

Theses : Honours

Relational database systems use join queries to retrieve data from two relations. Several join methods can be used to execute these queries. This study investigated the effect of varying join selectivity factors on the performance of the join methods. Experiments using the ORACLE environment were set up to measure the performance of three join methods: nested loop join, sort merge join and hash join. The performance was measured in terms of total elapsed time, CPU time and the number of I/O reads. The study found that the hash join performs better than the nested loop and the sort merge under …


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 …


Evaluating Information Modeling Methods – A Review, Keng Siau, M. Rossi Jan 1998

Evaluating Information Modeling Methods – A Review, Keng Siau, M. Rossi

Research Collection School Of Computing and Information Systems

Hundreds of modeling methods are in existence today, yet practitioners and researchers are zealously “producing” new modeling methods. The “blooming” of modeling methods is not the problem; the lack of standardized techniques for evaluating them is. To further complicate the matter, most of the modeling methods are introduced based on common sense and intuition. Theoretical foundations and empirical evidence are severely lacking. With the current state of affairs, evaluation of modeling methods has become necessary. Comparing modeling methods provides us with the necessary knowledge and understanding on the strengths and weaknesses of each method. This knowledge can also guide us …


Search For Evidence Of Compositeness At Lep I, R. Barate, M. Thulasidas Jan 1998

Search For Evidence Of Compositeness At Lep I, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

Extensive searches for evidence of compositeness of quarks and leptons have been made in the complete set of ALEPH data from LEP running at the Z peak. These include searches for radiative and weak decays of excited fermions, produced either in pairs or singly, and a scalar partner of the Z. Coupling and branching ratio limits deduced from these searches are presented.


An Interlibrary Loan System On The World Wide Web, Schubert Shou Boon Foo, Ee Peng Lim Jan 1998

An Interlibrary Loan System On The World Wide Web, Schubert Shou Boon Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Inter-Library Loan (ILL) service is one of the services provided by libraries that offers users a way to access library resources beyond their affiliated libraries. Additionally, it allows participating libraries to share and maximize their resources. This work examines the ILL process used by libraries in Singapore and proposes that the existing paper-based manual system be replaced by a Web-based ILL system. Such a Web-based system has been successfully designed and implemented at the Nanyang Technological University. The paper presents an overview of the system requirements and architecture, implementation details and demonstrates the feasibility and advantages of the new system.


Searches For Charginos And Neutralinos In E+E- Collisions At √S = 161 And 172 Gev, R. Barate, M. Thulasidas Jan 1998

Searches For Charginos And Neutralinos In E+E- Collisions At √S = 161 And 172 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The data recorded by the ALEPH detector at centre-of-mass energies of 161, 170, and 172 GeV are analysed for signals of chargino and neutralino production. No evidence of a signal is found, although candidate events consistent with the expectations from Standard Model processes are observed. Limits at 95% C.L. on the production cross sections are derived and bounds on the parameters of the Minimal Supersymmetric Standard Model are set. The lower limit on the mass of the lightest ch is 85.5 GeV/c2GeV/c2 for gaugino-like charginos (μ=−500GeV/c2μ=−500GeV/c2), and 85.0 GeV/c2GeV/c2 for Higgsino-like charginos (M2=500GeV/c2M2=500GeV/c2), for heavy sneutrinos (Mν~≥200GeV/c2Mν~≥200GeV/c2) and tanβ=2–√tan⁡β=2. The …


Search For Supersymmetry With A Dominant R-Parity Violating Llē Coupling In E+E- Collisions At Centre-Of-Mass Energies Of 130 Gev To 172 Gev, R. Barate, M. Thulasidas Jan 1998

Search For Supersymmetry With A Dominant R-Parity Violating Llē Coupling In E+E- Collisions At Centre-Of-Mass Energies Of 130 Gev To 172 Gev, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LLE¯LLE¯ coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130–172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This is translated into lower limits on the mass of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, charginos with masses less than 73 GeV/c2c2 and neutralinos with masses less than 23 GeV/c2c2 are excluded at 95% confidence level for any generation structure of the LLE¯LLE¯ coupling, and for neutralino, slepton …


Study Of B0s Oscillations And Lifetime Using Fully Reconstructed D̄S Decays, R. Barate, M. Thulasidas Jan 1998

Study Of B0s Oscillations And Lifetime Using Fully Reconstructed D̄S Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for B0sBs0 oscillations is performed using approximately 4 million Z→qq¯Z→qq¯ events collected by the ALEPH experiment during 1991–1995. B0sBs0 candidates are partially reconstructed by combining tracks with fully reconstructed D−sDs− candidates. The B0sBs0 production flavour is estimated from the sign of the opposite hemisphere charge, a fragmentation kaon in the same hemisphere, or a lepton in the opposite hemisphere. From a total sample of 1620 candidates, with a B0sBs0 purity estimated to be 22%, all values of ΔmsΔms below 3.9 ps−1−1 and between 6.5 and 8.8 ps−1−1 are excluded at 95% CL. From the same sample, the B0sBs0 …


Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas Jan 1998

Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


An Upper Limit On The Τ Neutrino Mass From Three- And Five-Prong Tau Decays, R. Barate, M. Thulasidas Jan 1998

An Upper Limit On The Τ Neutrino Mass From Three- And Five-Prong Tau Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at s√≃mZ with the ALEPH detector. Two separate limits are derived by fitting the distribution of visible energy vs invariant mass in τ−→2π−π+ντ and τ−→3π−2π+(π0)ντ decays. The two results are combined to obtain a 95% confidence level upper limit of 18.2 MeV/c2 on the mass of the tau neutrino.


Measurement Of The Fraction Of Hadronic Z Decays Into Charm Quark Pairs, R. Barate, M. Thulasidas Jan 1998

Measurement Of The Fraction Of Hadronic Z Decays Into Charm Quark Pairs, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

The full statistics of hadronic Z decays collected with the ALEPH detector are analysed to measure, by three methods, the ratio, RcRc, of the partial decay width of the Z into cc¯cc¯ quarks to the total hadronic width. One method uses the inclusive pp and p⊥p⊥ spectra of electrons. The other two use a double-tagging technique to measure RcRc independently of the charm-tagging efficiency. In one, the tagging procedure uses the reconstruction of high momentum charmed mesons (D∗+D∗+, D+D+ and \({\rm D^0}$) to detect the charm quarks. In the other, a charm quark is tagged from the D∗D∗'s reconstructed in …


User Response And Organisational Fit For Information Systems In Earth Observation, Jeff Kingwell Jan 1998

User Response And Organisational Fit For Information Systems In Earth Observation, Jeff Kingwell

Theses: Doctorates and Masters

A group of seventy six scientists and data managers in the Australian research agency CSIRO were surveyed to establish their needs and preferences in relation to information systems for Earth observation data. After study of available alternatives, three prototype Earth observation information management systems were installed and the user response was evaluated through interview of fifteen of the group. The prototypes consisted of web-based client servers which permitted users to interrogate databases of Earth observation datasets; to search for information about sensor or satellite performance, and to retrieve data and information products. The chosen systems were CILS, the CEOS (Committee …


Observation Of Doubly-Charmed B Decays At Lep, R. Barate, M. Thulasidas Jan 1998

Observation Of Doubly-Charmed B Decays At Lep, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for doubly-charmed B decays with both charmed mesons reconstructed is performed, using about 3.8 million hadronic Z decays recorded with the ALEPH detector at LEP. A clear signal is observed in the channels B→DsD¯(X)B→DsD¯(X) and B→DD¯(X)B→DD¯(X) (where D can be either a D00, a D++ or a D∗+∗+), providing the first direct evidence for doubly-charmed B decays involving no DsDs production. Evidence for associated K0SKS0 and K±K± production in the decays B→DD¯(X)B→DD¯(X) is also presented and some candidates for completely reconstructed decays B→DsD¯(nπ)B→DsD¯(nπ), B→DD¯K0SB→DD¯KS0 and B→DD¯K±B→DD¯K± are observed. Furthermore, candidates for the two-body Cabibbo suppressed decays B0→D∗−D∗+B0→D∗−D∗+ and …


Evaluation Of Information Modeling Methods: A Review, Keng Siau, Matti Rossi Jan 1998

Evaluation Of Information Modeling Methods: A Review, Keng Siau, Matti Rossi

Research Collection School Of Computing and Information Systems

Hundreds of modeling methods are in existence today. Yet practitioners and researchers are zealously "producing" new modeling methods. The "blooming" of modeling methods is not the problem; the lack of standardize techniques for evaluating them is. To further complicate the matter, most of the modeling methods are introduced based on common sense and intuition. Theoretical foundations and empirical evidence are severely lacking. With the current state of affairs, evaluation of modeling methods has become necessary. Comparing modeling methods provides us with the necessary knowledge and understanding on the strengths and weaknesses of each method. This knowledge can also guide us …