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Articles 7381 - 7410 of 7601

Full-Text Articles in Databases and Information Systems

Gnarly Rantings About The Hacker And The Ants, Rudy Rucker May 1996

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 May 1996

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 Mar 1996

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 …


Entity Identification In Database Integration, Ee Peng Lim, Jaideep Srivastava, Satya Prabhakar, James Richardson Feb 1996

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 …


A Precise Measurement Of The Average B Hadron Lifetime, D. Buskulic, M. Thulasidas Feb 1996

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.


Syllogism Solving Under Time Pressure, Gondy Leroy, Koen Lamberts Jan 1996

Syllogism Solving Under Time Pressure, Gondy Leroy, Koen Lamberts

CGU Faculty Publications and Research

No abstract provided.


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 …


Spieltheorie, Alexander Chocholaty, Pascal Hitzler Jan 1996

Spieltheorie, Alexander Chocholaty, Pascal Hitzler

Computer Science and Engineering Faculty Publications

No abstract provided.


Rex ' 96 : An Expert Guide To Revegetation, David Bicknell Jan 1996

Rex ' 96 : An Expert Guide To Revegetation, David Bicknell

Journal of the Department of Agriculture, Western Australia, Series 4

Agriculture Western Australia has provided coordination and technical input to a powerful source of information on plants for Australian conditions. David Bicknell outlines some of its features and uses.

Farmers, local government, advisers and even gardeners often have trouble finding the right plant for the right place for a given purpose. Rather than spend a lot of time, money and effort looking through scattered sources of information, many people stick with a limited number of species year after year. This neglects plants that may be much better suited to the purpose, and also fails to develop Australia's huge range of …


Tau Leptonic Branching Ratios, D. Buskulic, M. Thulasidas Jan 1996

Tau Leptonic Branching Ratios, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

A sample of 62249 τ-pair events is selected from data taken with the ALEPH detector in 1991, 1992 and 1993. The measurement of the branching fractions for τ decays into electrons and muons is presented with emphasis on the study of systematic effects from selection, particle identification and decay classification. The results obtained are: B e = 17.79±0.12(stat)±0.06(syst)(%) and Bμ = 17.31±0.11(stat)±0.05(syst)(%). Combined with the most recent ALEPH determination of the τ lifetime, these results provide a relative measurement of the leptonic couplings in the weak charged current for transverse W bosons: ${cal G}_{ώ}/{cal G}_{e}=1.0002pm 0.0051$ and ${cal G}_{∢u}/{cal G}_{u}=0.9943pm …


A Formal Preparation For Object-Oriented Query Optimisation, Catherine Higgins Jan 1996

A Formal Preparation For Object-Oriented Query Optimisation, Catherine Higgins

Articles

This paper describes work that is in progress on a formalised preparation to object-oriented query optimisation. Such preparation is conducive to the development of optimisation strategies. As an example of a formal preparation, this paper presents a formalised object algebra, a suggested optimisation method and an implementation of an algebraic converter suitable for DAPLEX.


Customer Feedback Information System For Quality Improvement, Ke Wang Jan 1996

Customer Feedback Information System For Quality Improvement, Ke Wang

Masters Theses

This research addressed the basic needs for an effective customer feedback information system and the database technology to develop the system. It discussed the system concept and configuration of a typical customer feedback information system, database management technology, programming flow charts, program functions and capabilities. A proposed customer feedback information system consists of customer data inputs, database management system and outputs to various departments in an organization. With a user-friendly interface, database management system serves as an information management tool. It can process the feedback from customers and use the information in decision making. Thus, customer feedback can be promptly …


Tau Hadronic Branching Ratios, D. Buskulic, M. Thulasidas Jan 1996

Tau Hadronic Branching Ratios, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

From 64492 selected τ-pair events, produced at the Z0 resonance, the measurement of the tau decays into hadrons from a global analysis using 1991, 1992 and 1993 ALEPH data is presented. Special emphasis is given to the reconstruction of photons and π0s, and the removal of fake photons. A detailed study of the systematics entering the π0 reconstruction is also given. A complete and consistent set of tau hadronic branching ratios is presented for 18 exclusive modes. Most measurements are more precise than the present world average. The new level of precision reached allows a stringent test τ-μ, universality in …


Measurement Of The Λb Polarization In Z Decays, Buskulic, D.; Et Al., M. Thulasidas Jan 1996

Measurement Of The Λb Polarization In Z Decays, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

The Λb polarization in hadronic Z decays is measured in semileptonic decays from the average energies of the charged lepton and the neutrino. In a data sample of approximately 3 million hadronic Z decays collected by the ALEPH detector at LEP between 1991 and 1994, 462 ± 31 Λb candidates are selected using (Λπ+)-lepton correlations. From this event sample, the Λb polarization is measured to be PΛb = −0.23−0.20+0.24(stat.)−0.07+0.08(syst.).


Determination Of Sin2Θw Eff Using Jet Charge Measurements In Hadronic Z Decays, D. Buskulic, M. Thulasidas Jan 1996

Determination Of Sin2Θw Eff Using Jet Charge Measurements In Hadronic Z Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured forbb¯bb¯ andcc¯cc¯ events in subsamples selected by their long lifetimes or using fastD*’s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite …


Improved Measurement Of The B0 And B+ Meson Lifetimes, D. Buskulic, M. Thulasidas Jan 1996

Improved Measurement Of The B0 And B+ Meson Lifetimes, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

Updated measurements of the B0 and B+ meson lifetimes are presented. From a data sample of 1.72 million hadronic Z0 decays recorded during the period 1991 to 1993, a sample of approximately 1000 semileptonic B meson decays containing a D0, D+ or D*+ has been isolated. From the distribution of decay times in the different samples the lifetimes of the B0 and B+ mesons are determined to be 1.53±0.12±0.08 ps and 1.52±0.14±0.09 ps, respectively, where the first error is statistical and the second systematic. The ratio of the B+ to B0 lifetimes is measured to be 0.99±0.14+0.05−0.04, confirming expectations that …


Simulation Modeling Within Workflow Technology, John A. Miller, Amit P. Sheth, Krzysztof J. Kochut, Xuzhong Wang, Arun Murugan Dec 1995

Simulation Modeling Within Workflow Technology, John A. Miller, Amit P. Sheth, Krzysztof J. Kochut, Xuzhong Wang, Arun Murugan

Kno.e.sis Publications

This paper presents an approach for integrating simulation modeling and analysis capabilities within the workflow management system (WFMS) being developed in the Large Scale Distributed Information Systems (LSDIS) Lab at the University of Georgia. Simulation modeling can be used for studying the efficiency of workflow designs as well as studying the general performance and reliability of WFMSs. We also discuss the importance of using sophisticated monitoring and animation capabilities, and the use of workflow management technology to advance simulation technology itself. Finally, we demonstrate a sample simulation where tasks and task managers are simulated.


The Effects Of Conceptual And Logical Interfaces On Visual Query Performance Of End Users, Keng Siau, H. Chan, K. Wei Dec 1995

The Effects Of Conceptual And Logical Interfaces On Visual Query Performance Of End Users, Keng Siau, H. Chan, K. Wei

Research Collection School Of Computing and Information Systems

To the end users, the interface is the system. A better interface not only facilitates end user interaction with the database, it also enables them to formulate queries more efficiently and effectively. Two of the most important user-database interfaces are the conceptual and logical interfaces. With the conceptual interface, the user communicates with tile database system in terms ofentities, objects and relationships. On the other hand, the current user-database interaction is mainly based on the logical interface where the user expresses the queries in terms of relations and join operations. Because the concepts at the logical iliterface are abstract and …


On The Equivalence Of Upward And Downward Inheritance Reasoners, Krishnaprasad Thirunarayan Nov 1995

On The Equivalence Of Upward And Downward Inheritance Reasoners, Krishnaprasad Thirunarayan

Kno.e.sis Publications

In this paper, we analyze systematically the downward (property flow) and the upward (individual flow) views of inheritance for different categories of inheritance networks. We observe that both these views assign the same meaning to tree-structured hierarchies, and explain the divergence in the interpretation of more general networks in terms of their expressive power. This simple analysis sheds light on the inherent nature of nonmonotonic inheritance and can form the basis for the design of efficient algorithms for certain classes of queries. In addition, we describe the notion of preferential inheritance to specify additional conflict resolution information that can be …


Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier Nov 1995

Quality Of Service Specification For Multimedia Presentations, Richard Staehli, Jonathan Walpole, David Maier

Computer Science Faculty Publications and Presentations

The bandwidth limitations of multimedia systems force tradeoffs between presentation data fidelity and real-time performance. For example, digital video is commonly encoded with lossy compression to reduce bandwidth and frames may be skipped during playback to maintain synchronization. These tradeoffs depend on device performance and physical data representations that are hidden by a database system. If a multimedia database is to support digital video and other continuous media data types, we argue that the database should provide a Quality of Service (QOS) interface to allow application control of presentation timing and information loss tradeoffs.

This paper proposes a data model …


Measurement Of The Bs0 Lifetime And Production Rate With Ds- ℓ+ Combinations In Z Decays, D. Buskulic, M. Thulasidas Nov 1995

Measurement Of The Bs0 Lifetime And Production Rate With Ds- ℓ+ Combinations In Z Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

A precise determination of the effective Bs0→K+K− lifetime can be used to constrain contributions from physics beyond the Standard Model in the Bs0 meson system. Conventional approaches select B meson decay products that are significantly displaced from the B meson production vertex. As a consequence, B mesons with low decay times are suppressed, introducing a bias to the decay time spectrum which must be corrected. This analysis uses a technique that explicitly avoids a lifetime bias by using a neural network based trigger and event selection. Using 1.0fb−1 of data recorded by the LHCb experiment, the effective Bs0→K+K− lifetime is …


Measurement Of The Effective B Quark Fragmentation Function At The Z Resonance, Buskulic, D.; Et Al., M. Thulasidas Sep 1995

Measurement Of The Effective B Quark Fragmentation Function At The Z Resonance, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B0 and B± mesons produced at the Z resonance is measured by reconstructing semileptonic decays B → ℓνℓD(X) or B→ ℓνℓD∗+(X). The charmed mesons are reconstructed through the decay modes D0 → K−π+, D0 → K−π+π−π+, D+ → K−π+π+ and D∗+→ D0π+. The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B∗ and B∗∗ production, the shape of the scaled energy distribution xE(b) for mesons containing a b …


Measurement Of Αs From Scaling Violations In Fragmentation Functions In E+E- Annihilation, D. Buskulic, Manoj Thulasidas Sep 1995

Measurement Of Αs From Scaling Violations In Fragmentation Functions In E+E- Annihilation, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

A study of scaling violations in fragmentation functions performed by the ALEPH collaboration at LEP is presented.


Air Force Materiel Command (Afmc) Modeling, Simulation, And Analysis (Ms&A) Interactive Database, Timothy J. Wagner Sep 1995

Air Force Materiel Command (Afmc) Modeling, Simulation, And Analysis (Ms&A) Interactive Database, Timothy J. Wagner

Theses and Dissertations

This study develops a high level, unifying taxonomy for Modeling, Simulation, and Analysis (MS&A) products for the Air Force Materiel Command (AFMC). AFMC is concerned that limited resources are being expended on duplicative MS&A efforts. No mechanism exists that would confirm or deny this concern, so it was suggested that a database could be developed to catalog and track AFMC's MS&A inventory. First, it was necessary to determine the information that a decision maker needs to select a suitable MS&A product. Potential traits and characteristics were identified through review of current regulatory guidance, interviews with MS&A users, and a study …


Group Creativity And Technology, Keng Siau Sep 1995

Group Creativity And Technology, Keng Siau

Research Collection School Of Computing and Information Systems

Despite the popularity of brainstorming, research has shown that verbal brainstorming is not always effective in increasing group creativity. On the other hand, its electronic counterpart, electronic brainstorming, appears to produce much better results. Is technology the panacea for group idea generation? This paper first reviews the theory of group creativity and then examines the characteristics of electronic brainstorming that makes it more effective than verbal brainstorming. From the success of electronic brainstorming, it then argues that the use of technology might be the key to overcome the space and time constraints that are commonly faced by creativity groups.


Measurements Of The B Baryon Lifetime, D. Buskulic, Manoj Thulasidas Sep 1995

Measurements Of The B Baryon Lifetime, D. Buskulic, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The average lifetime of b-flavoured baryons measured with the OPAL detector is updated to include data collected between 1990 and 1994 at LEP. Bottom-flavoured baryons that decay semileptonically and produce aΛ baryon are identified through the correlation of the baryon number of theΛ and the electric charge of the lepton. To measure the lifetime, the decay point of the b baryon is estimated by theΛ-lepton vertex, and the observed distribution of decay lengths is fitted simultaneously in 874 right-sign and 384 wrong-sign combinations. In a separate method, the impact parameter distribution of the leptons is fitted in a subset of …


Power Systems Marginal Cost Curve And Its Applications, Shaojun Wang, S. M. Shahidehpour, Nian-De Xiang Aug 1995

Power Systems Marginal Cost Curve And Its Applications, Shaojun Wang, S. M. Shahidehpour, Nian-De Xiang

Kno.e.sis Publications

This paper presents a forward recursive procedure to calculate the expected system marginal cost curve (EMC). The EMC formulation allows for multi-state and multi-block dispatch of generating units and is used to determine the optimal energy of pumped-storage units. A new approach is developed to compute the first and second derivatives of the expected generation energy of a thermal unit with respect to the capacity of all thermal units in the system. The salient feature of the proposed approach is that it applies to hydro-thermal systems with multiple limited-energy hydro units.


An Experimental Investigation Of The Effect Of Expert Decision Analyses And Explanations Support On Consensus And Decision Accuracy In Small Groups, Fiona Fui-Hoon Nah, I. Benbasat Aug 1995

An Experimental Investigation Of The Effect Of Expert Decision Analyses And Explanations Support On Consensus And Decision Accuracy In Small Groups, Fiona Fui-Hoon Nah, I. Benbasat

Research Collection School Of Computing and Information Systems

An Expert Support System (ESS) provides expert advice to complement the knowledge of the decision maker, and is intended to support , rather than replace, the decision maker. The ESS technology provides two fundamental functions: (1) the ability to perform analyses and draw conclusions by providing users with expert opinions, judgments, evaluations and advice; (2) the ability to explain its reasoning and conclusions. The usefulness of expert support technology has been evaluated in a number of empirical studies. However these studies either examined the organizational impact of the technology [e.g., 1] or the use of the technology by single individuals …


Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny Aug 1995

Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny

Research Collection School Of Computing and Information Systems

In recent years, a demand for real-time systems that can manipulate large amounts of shared data has led to the emergence of real-time database systems (RTDBS) as a research area. This paper focuses on the problem of scheduling queries in RTDBSs. We introduce and evaluate a new algorithm called Priority Adaptation Query Resource Scheduling (PAQRS) for handling both single class and multiclass query workloads. The performance objective of the algorithm is to minimize the number of missed deadlines, while at the same time ensuring that any deadline misses are scattered across the different classes according to an administratively-defined miss distribution. …


Measurement Of The D*± Cross Section In Two Photon Collisions At Lep, D. Buskulic, M. Thulasidas Aug 1995

Measurement Of The D*± Cross Section In Two Photon Collisions At Lep, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

The inclusive production of D∗± mesons in photon-photon collisions has been measured by the Aleph experiment at LEP with a beam energy of 45 GeV. The D∗+ are detected in their decay to D0π+ with the D0 observed in three separate decay modes: (1) K−π+, (2) K−π+π0 and (3) K−π+π−π+, and analagously for the D∗− modes. A total of 33 events was observed from an integrated luminosity of 73 pb−1 which corresponds to a cross section for Σ(e+e−→ e+e−D∗±X) of 155 ± 33 ± 21 pb. This result is compatible with both the direct production γγ → cc in the …