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Articles 6571 - 6600 of 6717

Full-Text Articles in Physical Sciences and Mathematics

Improved Tau Polarisation Measurement, D. Buskulic, M. Thulasidas Jan 1995

Improved Tau Polarisation Measurement, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

Using 22 pb−1 of data collected at LEP in 1992 on the peak of the Z resonance, the ALEPH collaboration has measured the polarisation of the tau leptons decaying intoevv¯,μvv¯evv¯,μvv¯,πν, ρν and a1 ν from their individual decay product distributions. The measurement of the tau polarisation as a function of the production polar angle yields the two parametersN τ andN e, where, in terms of the axial and vector couplingsg Al andg Vl,N l=2g Vl gAl/(g 2Vl+g2Al). This analysis follows to a large extent the methods devised for the 1990 and 1991 data but with improvements which bring a better …


Multiple Query Optimization With Depth-First Branch-And-Bound And Dynamic Query Ordering, Ee Peng Lim, Ahmet Cosar, Jaideep Srivastava Jan 1995

Multiple Query Optimization With Depth-First Branch-And-Bound And Dynamic Query Ordering, Ee Peng Lim, Ahmet Cosar, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

In certain database applications such as deductive databases, batch query processing, and recursive query processing etc., usually a single query gets transformed into a set of closely related database queries. Also, great benefits can be obtained by executing a group of related queries all together in a single unified multi-plan instead of executing each query separately. In order to achieve this Multiple Query Optimization (MQO) identifies common task(s) (e.g. common subexpressions, joins, etc.) among a set of query plans and creates a single unified plan (multi-plan) which can be executed to obtain the required outputs for all queries at once. …


A General Object Model Transformation System, John P. Mullaney Dec 1994

A General Object Model Transformation System, John P. Mullaney

Theses and Dissertations

Cecil and Fullenkamp developed a program that transforms knowledge captured in an object-model in one environment into a different object-model in a different environment. This program worked well for the intended purpose, but if one of the object-models is replaced by a different object-model then this transformation program has to be re-engineered. As the object-modeling paradigm becomes more prevalent, many systems are experiencing this problem. The primary goal of this research was to determine what reusable knowledge could be extracted from these types of program and used to build a general object-model transformer that generalizes such transformation programs. Toward this …


1.1, Yolanda Jones Nov 1994

1.1, Yolanda Jones

E-lert

No abstract provided.


1.0 Librarian's Supplement, Yolanda Jones Oct 1994

1.0 Librarian's Supplement, Yolanda Jones

E-lert

No abstract provided.


1.0, Yolanda Jones Oct 1994

1.0, Yolanda Jones

E-lert

No abstract provided.


The "Infoharness" Information Integration Platform, Leon Shklar, Satish Thatte, Howard Marcus, Amit P. Sheth Oct 1994

The "Infoharness" Information Integration Platform, Leon Shklar, Satish Thatte, Howard Marcus, Amit P. Sheth

Kno.e.sis Publications

The "InfoHarness" information integration platform, tools, and services being developed at Bellcore are aimed at providing integrated and rapid access to huge amounts of heterogeneous information independent of the type, representation, and location of information. InfoHarness provides advanced search and browsing capabilities without imposing the burden of restructuring, reformatting or relocating information on information suppliers or creators. This is achieved through object-oriented encapsulation of information and the associated meta-information (e.g., type, location, access rights, owner, creation date, etc.). The meta-information extraction methods ensure rapid and largely automatic creation of information repositories. A gateway that supports access to InfoHarness repositories from …


Does Pedagogy Make A Difference?: An Experimental Study Of Unethical Behavior In Information Systems, Deepak Khazanchi Oct 1994

Does Pedagogy Make A Difference?: An Experimental Study Of Unethical Behavior In Information Systems, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Jn the past few years ethics education has received increasing attention from the business and academic communities. Many have instituted pedagogical programs for increasing awareness of ethical issues, ethical norms and codes of conduct in different professions. It appears that both researchers and practitioners are in agreement about the need for providing adequate ethics education to managers (13, 20, 9). This has become especially important in the context of the information systems (IS) discipline. Proliferation of information and communication technologies has raised many questions on what constitutes ethical managerial behavior. Researchers have reported that the existence of a computer-based information …


Production And Decay Of D1 (2420)0 And D2* (2460)0, Avery, P.; Et Al., M. Thulasidas Jun 1994

Production And Decay Of D1 (2420)0 And D2* (2460)0, Avery, P.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Managing Memory For Real-Time Queries, Hwee Hwa Pang, Michael J. Carey, Miron Livny May 1994

Managing Memory For Real-Time Queries, Hwee Hwa Pang, Michael J. Carey, Miron Livny

Research Collection School Of Computing and Information Systems

The demanding performance objectives that real-time database systems (RTDBS) face necessitate the use of priority resource scheduling. This paper introduces a Priority Memory Management (PMM) algorithm that is designed to schedule queries in RTDBS. PMM attempts to minimize the number of missed deadlines by adapting both its multiprogramming level and its memory allocation strategy to the characteristics of the offered workload. A series of simulation experiments confirms that PMM's admission control and memory allocation mechanisms are very effective for real-time query scheduling.


The Myriad Federated Database Prototype, San-Yih Hwang, Ee Peng Lim, H. R. Yang, S. Musukula, K. Mediratta, M. Ganesh, D. Clements, J. Stenoien, Jaideep Srivastava May 1994

The Myriad Federated Database Prototype, San-Yih Hwang, Ee Peng Lim, H. R. Yang, S. Musukula, K. Mediratta, M. Ganesh, D. Clements, J. Stenoien, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

Myriad is a federated database system (FDBS) prototype being developed at the University of Minnesota. The main objective behind this prototyping effort is to provide "enterprise-wide" information by integrating independently developed databases while preserving the local autonomy of the component DBMSs and applications. In Myriad, multiple federations can be formed. A federation consists of an integrated database whose schema is represented as a set of integrated relations derived from the export relations provided by the component DBMSS. SQL, mainly due to its simplicity and popularity among database users and vendors, has been adopted to express global queries as well as …


Using Tickets To Enforce The Serializability Of Multidatabase Transactions, Dimitrios Georgakopoulos, Marek Rusinkiewicz, Amit P. Sheth Feb 1994

Using Tickets To Enforce The Serializability Of Multidatabase Transactions, Dimitrios Georgakopoulos, Marek Rusinkiewicz, Amit P. Sheth

Kno.e.sis Publications

To enforce global serializability in a multidatabase environment the multidatabase transaction manager must take into account the indirect (transitive) conflicts between multidatabase transactions caused by local transactions. Such conflicts are difficult to resolve because the behavior or even the existence of local transactions is not known to the multidatabase system. To overcome these difficulties, we propose to incorporate additional data manipulation operations in the subtransactions of each multidatabase transaction. We show that if these operations create direct conflicts between subtransactions at each participating local database system, indirect conflicts can be resolved even if the multidatabase system is not aware of …


Graphical Oodb Modeling For Medical Information Standards (Gommis), Jiping Liu Jan 1994

Graphical Oodb Modeling For Medical Information Standards (Gommis), Jiping Liu

Theses

The graphical representation of database schemata has been a useful tool for the designer and users of database systems. Such a tool for OODB schemata should incorporate a wide variety of symbols which cover most concepts of existing Object-Oriented Database (OODB), so it is sufficient to support a diverse group of object-oriented data models.

In this paper we created a. graphical representation, using the OOdini system and language, of the European Prestandard for Medical Informatics on Message Exchange of Laboratory Information. This European Prestandard describes a standardized format for messages to be exchanged between a. health care provider and a …


Managing Risks In Information Technology Projects, Boon Siong Neo, Kwong Sin Leong Jan 1994

Managing Risks In Information Technology Projects, Boon Siong Neo, Kwong Sin Leong

Research Collection School Of Accountancy

The development and implementation of IT (Information Technology) projects are plagued with problems of cost and time overruns. technical inadequacy, inability to meet user requirements. lack of utilization. and failure to achieve anticipated benefits. These problems occur to some projects and not to others because I) IT projects have different profiles of risk. and 2) IT project risks have been managed more or less effectively. This paper synthesizes the literature into four classes of risks. and applies it to evaluate TradeNet. an EDLbased trading system implemented in Singapore in I989. Through a case study of TradeNet. we derived a typology …


Relationship Between Information System Project Characteristics And Project Management Activities: An Empirical Investigation, Vijay V. Raghavan, Deepak Khazanchi, Joyce L. Webster Jan 1994

Relationship Between Information System Project Characteristics And Project Management Activities: An Empirical Investigation, Vijay V. Raghavan, Deepak Khazanchi, Joyce L. Webster

Information Systems and Quantitative Analysis Faculty Publications

The activities of a project manager in overseeing the development of a software system are many and varied. Not all such activities are performed in managing every project. If so, a natural ensuing question is whether project managers adapt their managerial functions to the projects being managed. Prior research suggests that they do adapt, and that project characteristics may be the factors determining this adaptation. This assertion is investigated by considering three characteristics of a project (size, type, and environment) and investigating their association with four traditionally recognized management functions (planning, organizing, controlling, and motivating). Results indicate that project managers …


An ‘Events’ Model For Information Aggregation, Douglas Havelka, Deepak Khazanchi Jan 1994

An ‘Events’ Model For Information Aggregation, Douglas Havelka, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Publications

Aggregation is one of the key characteristics of information delivered by "information systems." It is important because the ability to design effective support systems depends to a great extent upon the degree of flexibility with regards to information aggregation that can be incorporated in the system. This paper sets forth a conceptual model of information aggregation based on the events theory of accounting. The model suggests that aggregation should be considered as a two-dimensional concept, comprising a temporal and sectional dimension. The two axes are further delineated in the form of "levels of summation" based on specified "events" of aggregation. …


Measurement Of The Cross Section For Γγ→Pp̄, Artuso, M.; Et Al., M. Thulasidas Jan 1994

Measurement Of The Cross Section For Γγ→Pp̄, Artuso, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Resolving Attribute Incompatibility In Database Integration: An Evidential Reasoning Approach, Ee-Peng Lim, Shashi Shekhar Jan 1994

Resolving Attribute Incompatibility In Database Integration: An Evidential Reasoning Approach, Ee-Peng Lim, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel (1989) showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. The authors 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. They therefore propose an extended relational model based on Dempster-Shafer theory of evidence (1976) to incorporate such uncertain knowledge about the source databases. They also develop a full set of extended relational operations …


Exclusive Hadronic B Decays To Charm And Charmonium Final States, Alam, M.; Et Al., M. Thulasidas Jan 1994

Exclusive Hadronic B Decays To Charm And Charmonium Final States, Alam, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We have fully reconstructed decays of both B¯0 and B− mesons into final states containing either D, D*, D**, ψ, ψ’, or χc1 mesons. This allows us to obtain new results on many physics topics including branching ratios, tests of the factorization hypothesis, color suppression, resonant substructure, and the B−−B¯0 mass difference.


Measurement Of Cabibbo-Suppressed Decays Of The Τ Lepton, Battle, M.; Et Al., M. Thulasidas Jan 1994

Measurement Of Cabibbo-Suppressed Decays Of The Τ Lepton, Battle, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Measurement Of The Branching Fraction For D+K-++, Balest, R.; Et Al., M. Thulasidas Jan 1994

Measurement Of The Branching Fraction For D+K-++, Balest, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Using the CLEO II detector at the Cornell Electron Storage Ring we have measured the ratio of branching fractions, B(D+K-++)/(D0K-+)=2.350.160.16. Our recent measurement of scrB(D0K-+) then gives scrB(D+K-++)=(9.30.60.8)%.


Translation Of Semantic Aspects Of Oodini Graphical Representation To Onto Oodb Data Definition Language, Xiaoyong Wang Jan 1994

Translation Of Semantic Aspects Of Oodini Graphical Representation To Onto Oodb Data Definition Language, Xiaoyong Wang

Theses

In this thesis we present a system to translate the semantic elements in the graphical schema language of OODINI from API of OODAL to the Type definition of ONTOS DB. To translate semantic constraints of the graphical language, we patch more information to existent class data structure in API of OODAL. After a brief review of OODINI, ONTOS DB and the existent translator without the ability to translate semantic constraints, we describe in detail the methods to translate the essential relationship. dependent relationship, multi-valued essential relationship and multi-valued dependent relationship. We employ an Inverse Reference to a "Set of" Type …


Study Of The Five-Charged-Pion Decay Of The Τ Lepton, D. Gibaut, Manoj Thulasidas Jan 1994

Study Of The Five-Charged-Pion Decay Of The Τ Lepton, D. Gibaut, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The branching fractions for the five-charged-particle decays of the τ lepton have been measured in e+e− annihilations using the CLEO II detector at the Cornell Electron Storage Ring. Assuming all charged particles to be pions, the results are B(3π−2π+≥0 neutrals ντ)=(0.097±0.005±0.011)%, B(3π−2π+ντ)=(0.077±0.005 ±0.009)%, B(3π−2π+π0ντ)=(0.019±0.004±0.004)%, and B(3π−2π+2π0ντ)B(3π−2π−π0ντ) is measured for the first time by exclusive π0 reconstruction. The results are compared with the predictions from the partially conserved-axial-current and conserved-vector-current hypotheses assuming isospin invariance.


Observation Of A New Charmed Strange Meson, Kubota, Y.; Et Al., M. Thulasidas Jan 1994

Observation Of A New Charmed Strange Meson, Kubota, Y.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Precision Measurement Of The Ds*+-Ds+ Mass Difference, Brown, D.; Et Al., M. Thulasidas Jan 1994

Precision Measurement Of The Ds*+-Ds+ Mass Difference, Brown, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We have measured the vector-pseudoscalar mass splitting M(D*+s)-M(D+s)=144.22±0.47±0.37 MeV significantly more precisely than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference M(D*0)-M(D0) using the radiative decay D*0→D0γ, obtaining [M(D*+s)-M(D+s)]-[M(D*0)-M(D0)] =2.09±0.47±0.37 MeV. This is then combined with our previous high-precision measurement of M(D*0)-M(D0), which used the decay D*0→D0π0. We also measure the mass difference M(D+s)-M(D+)=99.5±0.6±0.3 MeV, using the φπ+ decay modes of the D+s and D+ mesons.


Identifying Faces Using Multiple Retrievals, Jian Kang Wu, Arcot Desai Narasimhalu Jan 1994

Identifying Faces Using Multiple Retrievals, Jian Kang Wu, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

During a police investigation, officers often have to sort through hundreds of photographs to identify a suspect. To aid this task, we at the Institute of Systems Science developed and implemented a flexible database system that can retrieve faces using personal information, fuzzy and free-text descriptors, and classification trees.


A Greedy Hypercube-Labeling Algorithm, D. Bhagavathi, C. E. Grosch, S. Olariu Jan 1994

A Greedy Hypercube-Labeling Algorithm, D. Bhagavathi, C. E. Grosch, S. Olariu

Computer Science Faculty Publications

Due to its attractive topological properties, the hypercube multiprocessor has emerged as one of the architectures of choice when it comes to implementing a large number of computational problems. In many such applications, Gray-code labelings of the hypercube are a crucial prerequisite for obtaining efficient algorithms. We propose a greedy algorithm that, given an n-dimensional hypercube H with N=22 nodes, returns a Gray-code labeling of H, that is, a labeling of the nodes with binary strings of length n such that two nodes are neighbors in the hypercube if, and only if, their labels differ in exactly …


Observation Of Inclusive B Decays To The Charmed Baryons C++ And C0, Procario, M.; Te Al., M. Thulasidas Jan 1994

Observation Of Inclusive B Decays To The Charmed Baryons C++ And C0, Procario, M.; Te Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


A Study Of The Approaches And Attitudes Of Information Systems Executives To Measuring Information Systems Effectiveness, Falantina Tjakra Jan 1994

A Study Of The Approaches And Attitudes Of Information Systems Executives To Measuring Information Systems Effectiveness, Falantina Tjakra

Theses: Doctorates and Masters

The purpose of the research is to examine the attitudes of IS executives to the current and future importance of some of the approaches to measuring IS efficiency and IS effectiveness in large Australian organisations. The study identified the nature of IS effectiveness approaches along the lines of whether they are business-oriented, IS internal/operational, financial, quantitative or qualitative measures. It also examined whether the structure of the IS management and industry sector had an effect on attitudes towards these measures.


The Management Of Information Technology Investments In The Australian Ambulance Services, Anthony J. Ahern Jan 1994

The Management Of Information Technology Investments In The Australian Ambulance Services, Anthony J. Ahern

Theses: Doctorates and Masters

Information Technology plays a significant role in the administration and operation of most organisations today. This is certainly the case with each of the Australian Ambulance Services. With the rapid increase in the use of Information Technology and the expectation about its use by both staff and the general public, the Ambulance Service managements' are faced with the dilemma of trying to ensure that their organisations are able to get the full advantage of advances in Information Technology and at the same time ensure that investments in IT are maintained at appropriate levels that will ensure the maximum return on …