Computer Sciences Commons^™

On Serializability Of Multidatabase Transactions Through Forced Local Conflict, Dimitrios Georgakopoulos, Marek Rusinkiewicz, Amit P. Sheth

Kno.e.sis Publications

The main difficulty in enforcing global serializability in a multidatabase environment lies in resolving indirect transitive conflicts between multidatabase transactions. Indirect conflicts introduced by local transactions are difficult to resolve because the behavior or even the existence of local transactions is not known to the multidatabase system. To overcome these problems, 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 their existence. Based …

An Efficient Semantic Query Optimization Algorithm, Hwee Hwa Pang, Hongjun Lu, Beng Chin Lu

Research Collection School Of Computing and Information Systems

An efficient semantic query optimization algorithm is proposed, in which all possible transformations are tentatively applied to the query. Instead of physically modifying the query, the transformation process classifies the predicates into imperative, optional or redundant. At the end of the transformation process, all the imperative predicates are retained while the redundant predicates are eliminated. Optional predicates are retrained or discarded based on the estimated cost/benefit of retaining them. The issue of the grouping of semantic constraints to reduce the overhead of retrieving constraints and checking whether each constraint is relevant to the current query is also addressed. Based on …

Concurrency Control, Version Management And Transactions In Advanced Database Systems, Jonathan Walpole, Muntuck Yap

Computer Science Faculty Publications and Presentations

This document constitutes the final deliverable for the research project titled “An Investigation of Selected Issues in Transaction Mechanism Design for Object Oriented Databases.” The document describes our ideas for extending the traditional transaction concept for use in object oriented databases, and concentrates specifically on providing an underlying model to support the concurrency control and version management aspects of the problem. The ideas presented here are not however restricted to the domain of object oriented databases. They are more generally applicable to database systems that require flexibility in their versioning and concurrency control policies.

In this document we define a …

Actuarial Computation Of Multiemployer Pension Plan Withdrawal Liability, Kelly A. Renze

Presidential Scholars Theses (1990 – 2006)

This project helps to demonstrate how pension actuaries must keep a constant eye on new laws. The pension industry is constantly bombarded with new laws which force them to alter policies and procedures. Because of the huge number of laws, it is difficult for all employees to fully understand every law. During my stay at the Principal, I discovered that many passages are interpreted differently by different people. I also uncovered some details through my research that other employees were not aware of.

Because of this complexity, it is often necessary to assign to one person, such as myself, the …

Three Denerations Of Dbms, Maria Skiba

Theses : Honours

This paper describes the evolution of data base technology from early computing to the sophisticated systems of today. It presents an overview of the most popular data base management systems architectures such as hierarchical, network, relational and object-oriented. The last section of this paper presents a view of the factors that will influence the future of data base technology.

Fuzzy Neural Logic Network And Its Learning Algorithms, Fiona Fui-Hoon Nah, Nah Fiona

Research Collection School Of Computing and Information Systems

The paper introduces the basic features of fuzzy neural logic network. Each fuzzy neural logic network model is trained from a set of knowledge in the form of examples using one of the three learning algorithms introduced. These three learning algorithms are the delta rule controlled learning algorithm and two mathematical construction algorithms, namely, the local learning method and the global learning method. Once the fuzzy neural logic network model is constructed, it is ready to accept any unknown input from the user. With a low percentage of mismatched features, output solution can be obtained.

Exclusive And Inclusive Semileptonic Decays Of B Mesons To D Mesons, R. Fulton, M. Thulasidas

Research Collection School Of Computing and Information Systems

We report new measurements of the branching fractions B ( B − → D 0 l − ¯ ν ) , B ( ¯ B 0 → D + l − ¯ ν ) , and B ( B − → D * 0 l − ¯ ν ) . Combining these results with our previous measurement of B ( ¯ B 0 → D * + l − ¯ ν ) , we find that the ratio of semileptonic widths for final states with a vector meson and pseudoscalar meson is ( 2.6 + 1.1 + 1.0 − 0.6 …

Inclusive Production Of The Charmed Baryon C+ From E+E- Annihilations At S=10.55 Gev, P. Avery, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

We report results on inclusive production of the charmed baryon Λc+ from e+e− annihilations at √s=10.5 GeV. Measurements are presented of the inclusive cross section times branching fraction for the continuum production of Λc+ as observed in six different decay modes, and of a new, improved value of the Λc+ mass. The inclusive cross section times the branching fraction into pK−π+ is measured to be 10.0±1.5±1.5 pb summed over all xp. The branching fractions of Λc+ into p¯K0, p¯K0π+π−, Λπ+, Λπ+π−π+, and Ξ−K+π+ relative to that into pK−π+ are measured to be 0.44±0.07±0.05, 0.43±0.12±0.04, 0.18±0.03±0.03, 0.65±0.11±0.12, and 0.15±0.04±0.03, respectively. The …

A Mergeable Double-Ended Priority Queue, S. Olariu, Z. Wen

Computer Science Faculty Publications

An implementation of a double-ended priority queue is discussed. This data structure referred to as min–max–pair heap can be built in linear time; the operations Delete-min, Delete-max and Insert take O(log n) time, while Find-min and Find-max run in O(1) time. In contrast to the min-max heaps, it is shown that two min–max–pair heaps can be merged in sublinear time. More precisely, two min–max–pair heaps of sizes n and k can be merged in time O(log (n/k) * log k).

Cascading Of Ever Adaptive Variation Of Lzw Algorithm With Arithmetic Coding Method, Ramesh Vishwanatham, Ketan Tejani

Theses

Two known compression algorithms appropriate for communication are LZW and the Arithmetic Coding method. Both algorithms are adaptive and require no extra communication from the encoder to the decoder. We have considered a variation of LZW algorithm known as Online version which result in better compression. Here we present a scheme to cascade Online LZW with Arithmetic algorithms into an Ever Adaptive data compression algorithm which achieves higher compression ratio and is appropriate for communication.

Access And Operator Methods For The Triton Nested Relational Database System, Tina M. Harvey

Theses and Dissertations

Unique database requirements in the realm of non-standard applications (such as computer-aided design (CAD), computer-aided software engineering(CASE), and office information systems (OIS) have driven the development of new data models and database systems based on these new models. In particular, the goal of these new database systems is to exploit the advantages of complex data models that are more efficient (in terms of time and space) than their relationship counterparts. This research effort describes the relational design and implementation of the Triton nested relational database system, a prototype system based on the nested relational data model. Triton is intended to …

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.

A Graphical Knowledge Level Approach For User-Database Interaction, K. Tan, H. Chan, Keng Siau

Research Collection School Of Computing and Information Systems

The authors propose a novel user interface, the Graphical Knowledge Level interface, for user-database interaction. This interface addresses two of the current research problems: the semantic inadequacy of the relational model and the logical data dependence of the relational languages. The interface is more user-friendly than the SOL interface and the Universal Relation interface, as it employs the graphical approach. The semantic inadequacy problem is alleviated by using an enhanced entity-relationship model. This data model includes abstraction concepts such as aggregation, generalization, and categorization. A formal, high-level Graphical Knowledge Level Query Language, GKQL, which provides for both logical and physical …

Bulletin No 4191 - Inputs For Beefin, D. J. Barker, P J. May, R. G. Grieve

Bulletins 4000 -

BEEFIN is a computer model (Barker et at. 1986) that calculates profit maximizing diets for finishing cattle to a specified carcass weight and fat thickness. It predicts cattle growth, feed conversion ratio, final liveweight, number of days on feed and amount of available feedstuffs to finish the cattle to specification.

BEEFIN calculates an enterprise profit and loss budget and performs a sensitivity analysis on cattle and feed price changes. A sensitivity analysis of returns to assets, variable costs and per tonne of feed fed is also calculated.

Cascading Of Arithematic Coding Method With The Lzw Algorithm, Venkat R. Maram, Nageshwar R. Kadakuntla

Theses

Two known compression algorithms appropriate for communication are the LZW algorithm and the Arithmetic Coding method. Both algorithms are adaptive and require no extra communication from the encoder to the decoder. We present a scheme to cascade these algorithms into an adaptive algorithm which achieves higher compression ratio and is appropriate for communication.

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

Marine Affairs 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

Marine Affairs 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 …

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

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.

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 …

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.

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.

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.

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 …

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.

Attribute Relationships: An Impediment In Automating Schema Integration, Amit P. Sheth, Sunit K. Gala

Kno.e.sis Publications

Success in schema integration depends on understanding the semantics of schema components (e.g., entity sets, relationship sets, attributes), and the ability to capture and reason about these semantics. An important objective of our work on schema integration is to automate the reasoning as much as possible, and when not possible, depend on the human input and guidance. A key results of comparing the semantics associated with schema objects is that of determining attribute relationship. Once attribute relationships are determined, the task of object class(e.g., entity sets and relationship sets) integration becomes simpler and can e automated to a great extent. …

Data Base Design For Research In Comparative Zapotec, Anita C. Bickford

Theses and Dissertations

This thesis explores the nature and content of a comparative data base for the Zapotec languages of Mexico that may be produced. Many questions are discussed: how to sub-divide and list the Zapotec languages and dialects; what data format will be most accessible to researchers as well as to field workers with data to add; computer software considerations (designing computational tools); how to handle non-cognates with shared meanings, non-overlap of glosses (i.e., one Zapotec gloss covers several Spanish words, or vice versa), semantic shifts and secondary meanings, and other problems such as special characters, free variation, elisions, etc.; whether to …

Ua66/3/2 Computer Science Alumni Newsletter, Vol. 5, Wku Computer Science

WKU Administration Documents

Newsletter created by WKU Computer Science for the alumni of the program.

Fault Tolerance In A Very Large Database System: A Strawman Analysis, Amit P. Sheth

Kno.e.sis Publications

A simple model is used to study the effect of fault-tolerance techniques and system design on system availability. A generic multiprocessor architecture is used that can be configured in different ways to study the effect of system architectures. Important parameters studied are different system architectures and hardware fault-tolerance techniques, mean time to failure of basic components, database size and distribution, interconnect capacity, etc. Quantitative analysis compares the relative effect of different parameter values. Results show that the effect of different parameter values on system availability can be very significant. System architecture, use of hardware fault tolerance (particularly mirroring), and data …