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Physical Sciences and Mathematics Commons

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1990

Databases and Information Systems

Articles 1 - 12 of 12

Full-Text Articles in Physical Sciences and Mathematics

Management Of Interdependent Data: Specifying Dependency And Consistency Requirements, Amit P. Sheth, Marek Rusinkiewicz Nov 1990

Management Of Interdependent Data: Specifying Dependency And Consistency Requirements, Amit P. Sheth, Marek Rusinkiewicz

Kno.e.sis Publications

Multiple databases that serve the needs of various application systems are considered. One of the significant problems in managing these databases is to maintain the related data items consistent to the required degree. This problem is frequently referred to as `redundant data management'. Since the term `redundancy' tends to imply that the data is unwanted or superfluous, the authors use the more general term `management of interdependent data'. Some preliminary ideas in this area are discussed. The problem of managing interdependent data is characterized, and some important types of interdatabase dependency are identified.


Software Validation Techniques : A Contrast Between Myers' And Hetzel's Techniques, Reyad I. Abukaker May 1990

Software Validation Techniques : A Contrast Between Myers' And Hetzel's Techniques, Reyad I. Abukaker

Electronic Dissertations and Theses

This research work presents the contemporary testing methodologies of current state-of-the-art methodologies in software testing. Myers' and Hetzel's methodologies are the primary objectives of this research. The scope of this work is to contrast these two testing methodologies, through looking at their principles as well as their definitions of testing. The two definitions of testing differ substantially. Myers' philosophy deals with human psychology and economics as the primary factors in defining the test plans. Hetzel's philosophy is broad in that it looks at software testing in terms of "meeting requirements." However, Hetzel focuses toward "evaluating" and "measuring" a software system …


An Underwater Science And Resource Database Management System And Proposed Applications To Marine Geographic Information Systems, Ivar Babb Jan 1990

An Underwater Science And Resource Database Management System And Proposed Applications To Marine Geographic Information Systems, Ivar Babb

Theses and Major Papers

The National Undersea Research Program (NURP) is a federally-funded program that provides scientists with modern in situ technology that allows them to conduct research that goes beyond the constraints of traditional oceanographic methodology. NURP is comprised of five regional centers that administer underwater science, and through the principal investigators that are supported generate a vast quantity of diverse data. This data and information bank consists of the following: raw environmental data, logistical data, locational data, information about the scientists, video and still photograph documentation, and publication information. This paper describes the theory behind the implementation of a Database Management System …


The Use Of Remote Sensing Techniques And Geographic Information Systems By Coastal Managers In Rhode Island, Margaret H. Sano Jan 1990

The Use Of Remote Sensing Techniques And Geographic Information Systems By Coastal Managers In Rhode Island, Margaret H. Sano

Theses and Major Papers

Planners and managers must understand the physical and anthropogenic changes taking place within the coastal zone to provide effective management. Remote sensing techniques and Geographic Information Systems (GIS) are excellent tools for contributing data and analytical capabilities to identify possible conflicts within the coastal zone. This study examines the potential and actual use of these technologies by coastal managers within Rhode Island. Potential usage is discussed in terms of the range of data available and the feasibility of using the data for coastal problems. Also, GIS capabilities in Rhode Island are explored. Finally a survey designed to measure the actual …


Pipelining Data Compression Algorithms, R. L. Bailey, R. Mukkamala Jan 1990

Pipelining Data Compression Algorithms, R. L. Bailey, R. Mukkamala

Computer Science Faculty Publications

Many different data compression techniques currently exist. Each has its own advantages and disadvantages. Combining (pipelining) multiple data compression techniques could achieve better compression rates than is possible with either technique individually. This paper proposes a pipelining technique and investigates the characteristics of two example pipelining algorithms. Their performance is compared with other well-known compression techniques.


Efficient Schemes To Evaluate Transaction Performance In Distributed Database Systems, R. Mukkamala, S. C. Bruell Jan 1990

Efficient Schemes To Evaluate Transaction Performance In Distributed Database Systems, R. Mukkamala, S. C. Bruell

Computer Science Faculty Publications

Database designers and researchers often need efficient schemes to evaluate transaction performance. In this paper, we chose two important performance measures: the average number of nodes accessed and the average number of data items accessed per node by a transaction in a distributed database system. We derive analytical expressions to evaluate these metrics. For general applicability, we consider partially replicated distributed database systems. Our first set of analytic results are closed-form expressions for these two measures. These are based on some fairly restrictive simplifying assumptions. When these assumptions are relaxed, no closed-form expressions exist for these averages. Hence, we develop …


Exclusive And Inclusive Decays Of B Mesons Into Ds Mesons, D. Bortoletto, Manoj Thulasidas Jan 1990

Exclusive And Inclusive Decays Of B Mesons Into Ds Mesons, D. Bortoletto, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

We have studied the production of Ds mesons in the decays of B mesons at the Υ(4S) resonance. We report on the first observation of exclusive B-meson decays B->Ds−D*+, B→Ds−D+, and B→Ds−D0. We also present a new measurement of the branching ratio and the momentum spectrum for the inclusive decay B→DsX.


Measurement Of The C+ Decay-Asymmetry Parameter, Avery, P.; Et Al., M. Thulasidas Jan 1990

Measurement Of The C+ Decay-Asymmetry Parameter, Avery, P.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We report a measurement of polarization in the two-body decay c+, in nonresonant e+e- interactions from data taken with the CLEO detector. Using these data we have determined the parity-violating asymmetry decay parameter c to be -1.0-0.0+0.4. We see no evidence for significant c+ polarization.


Performance Analysis Of A Distributed File System, Meenakshi Mukhopadhyay Jan 1990

Performance Analysis Of A Distributed File System, Meenakshi Mukhopadhyay

Dissertations and Theses

An important design goal of a distributed file system, a component of many distributed systems, is to provide UNIX file access semantics, e.g., the result of any write system call is visible by all processes as soon as the call completes. In a distributed environment, these semantics are difficult to implement because processes on different machines do not share kernel cache and data structures. Strong data consistency guarantees may be provided only at the expense of performance.

This work investigates the time costs paid by AFS 3.0, which uses a callback mechanism to provide consistency guarantees, and those paid by …


Observation Of B-Meson Semileptonic Decays To Noncharmed Final States, Fulton, R.; Et Al., M. Thulasidas Jan 1990

Observation Of B-Meson Semileptonic Decays To Noncharmed Final States, Fulton, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Pumps : A Method Of Financially Assessing Groundwater Pumping Used To Mitigate Salinity In South-Western Australia, Richard J. George Dr Jan 1990

Pumps : A Method Of Financially Assessing Groundwater Pumping Used To Mitigate Salinity In South-Western Australia, Richard J. George Dr

Resource management technical reports

No abstract provided.


Observation Of Iv(4=S) Decays Into Non-=Bba Final States Containing I Mesons, Alexander, J.; Et Al., M. Thulasidas Jan 1990

Observation Of Iv(4=S) Decays Into Non-=Bba Final States Containing I Mesons, Alexander, J.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We report on the observation of ; mesons from T(4S) decays which are too energetic to come from 8 mesons. These events provide evidence for non-88 decays of the T (4S). The measured rate is B(T(4S)+fX)=0.22•0.06•0.041 for ; momentum above 2 GeV/c.