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Articles 56341 - 56370 of 57960

Full-Text Articles in Physical Sciences and Mathematics

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.


Educational Software Development Using Hypertext And Expert System Software Concepts, Siripong Malasri, Roger R. Easson Jan 1990

Educational Software Development Using Hypertext And Expert System Software Concepts, Siripong Malasri, Roger R. Easson

Journal of the Arkansas Academy of Science

This paper presents two computer software concepts: hypertext and expert systems; which are useful for educational software development. Good educational software enhances the learning process and offers opportunities for faculty to provide additional materials for independent studies, which would otherwise be impossible, due to the limited time and incredible growing rate of technological progress. The hypertext concept offers the students a non-linear learning style, while the expert system concept provides explanation facilities for students to probe the logic of the systems. Both approaches are extremely useful for educational software. With the proper tools, the courseware can be implemented easily and …


Performance Improvements For Fddi And Csma/Cd Protocols, David Earl Game Jan 1990

Performance Improvements For Fddi And Csma/Cd Protocols, David Earl Game

Computer Science Theses & Dissertations

The High-Performance Computing Initiative from the White House Office of Science and Technology Policy has defined 20 major challenges in science and engineering which are dependent on the solutions to a number of high-performance computing problems. One of the major areas of focus of this initiative is the development of gigabit rate networks to be used in environments such as the space station or a National Research and Educational Network (NREN).

The strategy here is to use existing network designs as building blocks for achieving higher rates, with the ultimate goal being a gigabit rate network. Two strategies which contribute …


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.


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.


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.


A Dsm-Iii-R Study Of Computer Addiction Among Iowa Computer Users, Randy Young Jan 1990

A Dsm-Iii-R Study Of Computer Addiction Among Iowa Computer Users, Randy Young

CCE Theses and Dissertations

No abstract provided.


Experimentation With Large-Grained Parallelism Using Local Area Networks, Ralph W. Wilkerson, Douglas E. Meyer Jan 1990

Experimentation With Large-Grained Parallelism Using Local Area Networks, Ralph W. Wilkerson, Douglas E. Meyer

Computer Science Faculty Research & Creative Works

HIGHLAND, a distributed-memory parallel processing environment for heterogeneous local area networks, has been developed. Designed as both a teaching and a research tool, its purpose is to provide an effective mechanism by which a number of networked UNIX workstations, dissimilar in both vendor and performance, can be directly manipulated as a single, unified, multiprocessing system. Utilizing the MIT X-windows environment, HIGHLAND supports a highly interactive graphical interface through which a programmer can create, modify, and control complex systems of communicating processes


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.


Data Constraints In Function-Oriented Languages, Earl Stavis Harris Jan 1990

Data Constraints In Function-Oriented Languages, Earl Stavis Harris

Dissertations, Theses, and Masters Projects

No abstract provided.


Benchmarking Parallel Machines Via A Software Architecture, Srikanth Kambhatla, Jon Inouye, Jonathan Walpole Jan 1990

Benchmarking Parallel Machines Via A Software Architecture, Srikanth Kambhatla, Jon Inouye, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The diversity in parallel architectures and the programming styles induced thereof, make benchmarking of parallel machines a hard problem. Current benchmarking techniques are limited in applicability due to the issues of portability. We present a different approach to benchmarking parallel machines, which would make the resulting benchmarks portable, easy to use and widely applicable. The approach involves the use of a software architecture to mask the diversities of the underlying architectures. The benchmarks are based on the Linda Tuple Space, and is called BeLinda. In this report, we motivate the use of a software architecture, give a specification of the …


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 …


Wings And Perfect Graphs, Stephan Olariu Jan 1990

Wings And Perfect Graphs, Stephan Olariu

Computer Science Faculty Publications

An edge uv of a graph G is called a wing if there exists a chordless path with vertices u, v, x, y and edges uv, vx, xy. The wing-graph W(G) of a graph G is a graph having the same vertex set as G; uv is an edge in W(G) if and only if uv is a wing in G. A graph G is saturated if G is isomorphic to W(G). A star-cutset in a graph G is a non-empty set of …


A Dynamic Failure Model For Performing Propagation And Infection Analysis On Computer Programs, Jeffrey Mark Voas Jan 1990

A Dynamic Failure Model For Performing Propagation And Infection Analysis On Computer Programs, Jeffrey Mark Voas

Dissertations, Theses, and Masters Projects

This thesis introduces a methodology for determining program locations where faults can easily hide. It is a program structure-based model that analyzes program flow both statically and dynamically; each program location is analyzed relative to its preceding locations and succeeding locations. A statistical model termed propagation analysis studies the relation between incorrect internal data states and their affect on the output. Infection analysis is a statistically model which studies the relation between classes of faults and internal data states. Together these two models combine to form one model of analyzing programs termed Propagation and Infection Analysis (PIA).;PIA employs aspects of …


Knowledge-Based System For Flight Information Management, Wendell R. Ricks Jan 1990

Knowledge-Based System For Flight Information Management, Wendell R. Ricks

Dissertations, Theses, and Masters Projects

No abstract provided.


Digital Image Processing Using Mathematical Morphology, Andrew Mehnert Jan 1990

Digital Image Processing Using Mathematical Morphology, Andrew Mehnert

Theses : Honours

This dissertation is a natural extension of my undergraduate research project entitled, "Digital Image Processing”. Whilst my undergraduate project dealt with a number of classical digital image filtering techniques such as spatial convolution and frequency domain filtering via the Fourier transform, this dissertation focuses on an alternative approach employing Mathematical Morphology. In contrast to classical filtering techniques, which often geometrically distort the original image, morphological operations, used sensibly, essentially preserve shape and geometry. Mathematical morphology therefore lends itself to image processing applications requiring the identification of objects and object features within an image. Herein basic morphological operations are developed, firstly …


Data Security: The Securing Of Computer Installations And Data Sets, Willy B. Kuehnle Jan 1990

Data Security: The Securing Of Computer Installations And Data Sets, Willy B. Kuehnle

Theses

No abstract provided.


Management Information Sources And Corporate Intelligence Systems, Robert F. Gordon Ph.D. Jan 1990

Management Information Sources And Corporate Intelligence Systems, Robert F. Gordon Ph.D.

Faculty Works: MCS (1984-2023)

In this book the word “intelligence” is used in several different contexts. Intelligence can refer to the process of gathering data; it can refer to the data itself; and it can refer to the application of knowledge to product useful information from the data. We will see in this chapter how the computer can be used in business to further all three aspects of intelligence: capturing the data, storing the data in an accessible form, and adding value to the data by transforming it into useful information for decision making. This chapter is organized according to these three areas of …


Trellis-Coded Multidimensional Phase Modulation, S. S. Pietrobon, Robert H. Deng Jan 1990

Trellis-Coded Multidimensional Phase Modulation, S. S. Pietrobon, Robert H. Deng

Research Collection School Of Computing and Information Systems

A 2L-dimensional multiple phase-shift keyed (L×MPSK) signal set is obtained by forming the Cartesian product of L two-dimensional MPSK signal sets. A systematic approach to partitioning L×MPSK signal sets that is based on block coding is used. An encoder system approach is developed. It incorporates the design of a differential precoder, a systematic convolutional encoder, and a signal set mapper. Trellis-coded L×4PSK, L×8PSK, and L×16PSK modulation schemes are found for 1⩽L⩽4 and a variety of code rates and decoder complexities, many of which are fully transparent to discrete phase rotations of the signal set. The new codes achieve asymptotic coding …


The Development Of An Expert System For The Diagnosis Of Diseases In Fibre And Dairy Goats, Tim S. Roberts Jan 1990

The Development Of An Expert System For The Diagnosis Of Diseases In Fibre And Dairy Goats, Tim S. Roberts

Theses: Doctorates and Masters

This thesis details the development of an expert system for the diagnosis of diseases in fibre and dairy goats. Divided into five sections, five appendices, and a bibliography, this thesis centres on the methods used to build the expert system: the decisions taken at the outset of, and during the course of, development; some of the problems encountered, and the solutions to those problems. A detailed appraisal is made of the development process and suggestions are made for future developments over similar domains (for example, the diagnosis of diseases in animals other than goats). Much emphasis is placed on three …


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 …


A Method For Assessing Software Measurement Technology, Robert Yacobellis Dec 1989

A Method For Assessing Software Measurement Technology, Robert Yacobellis

Robert H Yacobellis

No abstract provided.


Parallel Machines: Parallel Machine Languages, Robert Iannucci Dec 1989

Parallel Machines: Parallel Machine Languages, Robert Iannucci

Robert A Iannucci

No abstract provided.


What One Intelligence Test Measures: A Theoretical Account Of The Processing In The Raven Progressive Matrices Test, Patricia A. Carpenter, Marcel Adam Just, Peter Shell Dec 1989

What One Intelligence Test Measures: A Theoretical Account Of The Processing In The Raven Progressive Matrices Test, Patricia A. Carpenter, Marcel Adam Just, Peter Shell

Marcel Adam Just

No abstract provided.


Positive Residues Involved In The Voltage-Gating Of The Mitochondrial Porin-Channel Are Localized In The External Moiety Of The Pore, Philadelphia University Dec 1989

Positive Residues Involved In The Voltage-Gating Of The Mitochondrial Porin-Channel Are Localized In The External Moiety Of The Pore, Philadelphia University

Philadelphia University, Jordan

No abstract provided.


An Analogue In Certain Unique Factorization Domains Of The Euclid-Euler Theorem On Perfect Numbers, Wayne L. Mcdaniel Dec 1989

An Analogue In Certain Unique Factorization Domains Of The Euclid-Euler Theorem On Perfect Numbers, Wayne L. Mcdaniel

UMSL Emeritus

We show that there exists a natural extention of the sum of divisors function to all unique factorization domains F having a finite number of units such that if a perfect number in F is defined to be an integer η whose proper divisors sum to η, then the analogue of Euclid's theorem giving the sufficient condition that an integer be an even perfect number holds in F, and an analogue of the Euclid-Euler theorem giving the necessary and sufficient condition that an even integer be perfect holds in those domains having more than two units, i. e., in Q(−1) …


Development Of An Expert System To Convert Knowledge-Based Geological Engineering Systems Into Fortran, Jill J. Cress, Ralph W. Wilkerson Dec 1989

Development Of An Expert System To Convert Knowledge-Based Geological Engineering Systems Into Fortran, Jill J. Cress, Ralph W. Wilkerson

Computer Science Technical Reports

A knowledge-based geographic information system (KBGIS) for geological engineering map (GEM) production was developed in GoldWorks, an expert system development shell. GoldWorks allows the geological engineer to develop a rule base for a GEM application. Implementation of the resultant rule base produced a valid GEM, but took too much time. This proved that knowledge-based GEM production was possible but in GoldWorks implementation failed as a practical production system. To solve this problem, a Conversion Expert System was developed which accepted, as input, a KBGIS and produced, as output, the equivalent Fortran code. This allowed the engineer to utilize GoldWorks for …


The Directed Steiner Problem On Graphs: A Simulated Annealing Approach, Lawrence Joseph Osborne, Billy E. Gillett Dec 1989

The Directed Steiner Problem On Graphs: A Simulated Annealing Approach, Lawrence Joseph Osborne, Billy E. Gillett

Computer Science Technical Reports

The well-known Steiner Problem on Graphs is an NP-complete problem for which there are many heuristic and exact algorithms that are deterministic. In this dissertation a new approach to the directed version of this problem is made by applying the ideas of statistical mechanics through the use of the method of simulated annealing. A version of annealing is developed for the Directed Steiner Problem and compared with one of the best general annealing schemes. Then a comparison is made between simulated annealing and the traditional branch and bound technique. The dual ascent algorithm of Richard T. Wong is used to …


A Methodology For Developing Correct Rule-Based Programs For Parallel Implementation, Rosanne Fulcomer Gamble Dec 1989

A Methodology For Developing Correct Rule-Based Programs For Parallel Implementation, Rosanne Fulcomer Gamble

All Computer Science and Engineering Research

Production systems, also called rule-based systems, are very useful in automating certain human expert tasks, but the current technology exhibits many problems. We believe that parallelism is difficult to exploit in production system programs for two reasons. First, the original serial programs are designed with a priori knowledge of an explicit global control mechanism which must be simulated for correct execution in parallel. The second reason for the difficulty is that no formal language exists in which to express these programs and no verification techniques are utilized to prove properties which guarantee correct execution in parallel. With these two obstacles …