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Articles 53791 - 53820 of 58014

Full-Text Articles in Physical Sciences and Mathematics

Evolutionary Computation Applied To Adaptive Information Filtering, Daniel R. Tauritz, Ida G. Sprinkhuizen-Kuyper, Joost N. Kok Jan 1997

Evolutionary Computation Applied To Adaptive Information Filtering, Daniel R. Tauritz, Ida G. Sprinkhuizen-Kuyper, Joost N. Kok

Computer Science Faculty Research & Creative Works

Information Filtering is concerned with filtering data streams in such a way as to leave only pertinent data (information) to be perused. When the data streams are produced in a changing environment the filtering has to adapt too in order to remain effective. Adaptive Information Filtering is concerned with filtering in changing environments. The changes may occur both on the transmission side (the nature of the streams can change), and on the reception side (the interest of a user can change). Weighted trigram analysis is a quick and flexible technique for describing the contents of a document. A novel application …


A Comparison Of Annealing Techniques For Academic Course Scheduling, M.A. Saleh Elmohamed, Geoffrey C. Fox, Paul Coddington Jan 1997

A Comparison Of Annealing Techniques For Academic Course Scheduling, M.A. Saleh Elmohamed, Geoffrey C. Fox, Paul Coddington

Northeast Parallel Architecture Center

In this study we have tackled the NP-hard problem of academic class scheduling (or timetabling) at the university level. We have investigated a variety of approaches based on simulated annealing, including mean-field annealing, simulated annealing with three different cooling schedules, and the use of a rule-based preprocessor to provide a good initial solution for annealing. The best results were obtained using simulated annealing with adaptive cooling and reheating as a function of cost, and a rule-based preprocessor. This approach enabled us to obtain valid schedules for the timetabling problem for a large university, using a complex cost function that includes …


Random Number Generators For Parallel Computers, Paul D. Coddington Jan 1997

Random Number Generators For Parallel Computers, Paul D. Coddington

Northeast Parallel Architecture Center

Random number generators are used in many applications, from slot machines to simulations of nuclear reactors. For many computational science applications, such as Monte Carlo simulation, it is crucial that the generators have good randomness properties. This is particularly true for large-scale simulations done on high-performance parallel computers. Good random number generators are hard to find, and many widely-used techniques have been shown to be inadequate. Finding high-quality, efficient algorithms for random number generation on parallel computers is even more difficult. Here we present a review of the most commonly-used random number generators for parallel computers, and evaluate each generator …


Expert System For The Generation Of A Work Breakdown Structure, Bernard O'Callaghan Jan 1997

Expert System For The Generation Of A Work Breakdown Structure, Bernard O'Callaghan

Theses

This thesis outlines research work carried out in the Mechanical & Manufacturing Department in Cork Regional Technical College, Ireland. With computers now having an increasingly dominant role in all areas of business, it was inevitable that computer-based project management packages would become more popular. To date however, these packages have concentrated on monitoring and controlling projects. The definition and brainstorming phases required to generate a project plan are still largely manual tasks. Planning a project initially involves generating a complete and organised list of all the tasks needing to be completed in order to achieve a project’s goal. This list …


Balancing Consistency And Lag In Transaction-Based Computational Steering, Eileen Kraemer, Delbert Hart, Gruia-Catalin Roman Jan 1997

Balancing Consistency And Lag In Transaction-Based Computational Steering, Eileen Kraemer, Delbert Hart, Gruia-Catalin Roman

All Computer Science and Engineering Research

Computational steering, the interactive adjustment of application parameters and allocation of resources, is a promising technique for higher-productivity simulation, finer-grained optimization of dynamically varying algorithms, and greater understanding of program behavior and the characteristics of data sets and solution spaces. Tools for computational steering must provide monitoring, visualization, and interaction facilities. In addition, these tools must address issues related to the consistency, latency, and scalability at each of these phases, and must consider the perturbation that results. In this paper we describe transaction-based components for a computational steering system and present an approach that guarantees consistent monitoring and displays, supports …


A Fast Algorithm For Complete Subcube Recognition, Fikret Erçal, H. J. Burch Jan 1997

A Fast Algorithm For Complete Subcube Recognition, Fikret Erçal, H. J. Burch

Computer Science Faculty Research & Creative Works

The complete subcube recognition problem is defined as, given a collection of available processors on an n-dimensional hypercube, locate a subcube of dimension k that consists entirely of available processors, if one exists. Despite many algorithms proposed so far on this subject, improving the time complexity of this problem remains a challenge. Efficiency limits that can be reached have not been exhausted yet. This paper proposes a novel algorithm to recognize all the overlapping subcubes available on an n-dimensional hypercube whose processors are partially allocated. Given P=2n, as the total number of processors in the hypercube, the new algorithm runs …


Improving Minority Class Prediction Using Case-Specific Feature Weights, Claire Cardie, Nicholas Howe Jan 1997

Improving Minority Class Prediction Using Case-Specific Feature Weights, Claire Cardie, Nicholas Howe

Computer Science: Faculty Publications

This paper addresses the problem of handling skewed class distributions within the case-based learning (CBL) framework. We first present as a baseline an information gain-weighted CBL algorithm and apply it to three data sets from natural language processing (NLP) with skewed class distributions. Although overall performance of the baseline CBL algorithm is good, we show that the algorithm exhibits poor performance on minority class instances. We then present two CBL algorithms designed to improve the performance of minority class predictions. Each variation creates test-case-specific feature weights by first observing the path taken by the test case in a decision tree …


A Prototype Fortran-To-Java Converter, Geoffrey C. Fox, Xiaoming Li, Zheng Qiang, Wu Zhigang Jan 1997

A Prototype Fortran-To-Java Converter, Geoffrey C. Fox, Xiaoming Li, Zheng Qiang, Wu Zhigang

Northeast Parallel Architecture Center

This is a report on a prototype of a FORTRAN 77 to Java converter, f2j. Translation issues are identified, approaches are presented, a URL is provided for interested readers to download the package, and some unsolved problems are brought up. F2j allows value added to some of the investment onFORTRAN code, in particular, those well established FORTRAN libraries for scientific and engineering computation.


Evaluation Of High Performance Fortran Through Application Kernels, Hon W. Yau, Geoffrey C. Fox, Ken Hawick Jan 1997

Evaluation Of High Performance Fortran Through Application Kernels, Hon W. Yau, Geoffrey C. Fox, Ken Hawick

Northeast Parallel Architecture Center

Since the definition of the High Performance Fortran (HPF) standard, we have been maintaining a suite of application kernel codes with the aim of using them to evaluate the available compilers. This paper presents the results and conclusions from this study, for sixteen codes, on compilers from IBM, DEC, and the Portland Group Inc. (PGI), and on three machines: a DEC Alphafarm, an IBM SP-2, and a Cray T3D. From this, we hope to show the prospective HPF user that scalable performance is possible with modest effort, yet also where the current weaknesses lay.


Java For Parallel Computing And As A General Language For Scientific And Engineering Simulation And Modeling, Geoffrey C. Fox, Wojtek Furmanski Jan 1997

Java For Parallel Computing And As A General Language For Scientific And Engineering Simulation And Modeling, Geoffrey C. Fox, Wojtek Furmanski

Northeast Parallel Architecture Center

We discuss the role of Java and Web technologies for general simulation. We classify the classes of concurrency typical in problems and analyze separately the role of Java in user interfaces, coarse grain software integration, and detailed computational kernels. We conclude that Java could become a major language for computational science, as it potentially offers good performance, excellent user interfaces, and the advantages of object-oriented structure.


Webflow - A Visual Programming Paradigm For Web/Java Based Coarse Grain Distributed Computing, Dimple Bhatia, Vanco Burzevski, Maja Camuseva, Geoffrey C. Fox Jan 1997

Webflow - A Visual Programming Paradigm For Web/Java Based Coarse Grain Distributed Computing, Dimple Bhatia, Vanco Burzevski, Maja Camuseva, Geoffrey C. Fox

Northeast Parallel Architecture Center

We present here the recent work at NPAC aimed at developing WebFlow---a general purpose Web based visual interactive programming environment for coarse grain distributed computing. We follow the 3-tier architecture with the central control and integration WebVM layer in tier-2, interacting with the visual graph editor applets in tier-1 (front-end) and the legacy systems in tier-3. WebVM is given by a mesh of Java Web servers such as Jeeves from JavaSoft or Jigsaw from MIT/W3C. All system control structures are implemented as URL-addressable servlets which enable Web browser-based authoring, monitoring, publication, documentation and software distribution tools for distributed computing. We …


Experiments With "Hp Java", Bryan Carpenter, Yuh-Jye Chang, Geoffrey C. Fox, Donald Leskiw Jan 1997

Experiments With "Hp Java", Bryan Carpenter, Yuh-Jye Chang, Geoffrey C. Fox, Donald Leskiw

Northeast Parallel Architecture Center

We consider the possible role of Java as a language for High Performance Computing. After discussing reasons why Java may be a natural candidate for a portable parallel programming language, we describe several case studies. These cover Java socket programming, message-passing through a Java interface to MPI, and class libraries for data-parallel programming in Java.


Tango - A Collaborative Environment For The World-Wide Web, Lukasz Michal Beca, Gang Cheng, Geoffrey C. Fox, Tomasz Jurga, Konrad Olszewski, Marek Podgorny, Piotr Sokolowski, Tomasz Stachowiak, Krzysztof Walczak Jan 1997

Tango - A Collaborative Environment For The World-Wide Web, Lukasz Michal Beca, Gang Cheng, Geoffrey C. Fox, Tomasz Jurga, Konrad Olszewski, Marek Podgorny, Piotr Sokolowski, Tomasz Stachowiak, Krzysztof Walczak

Northeast Parallel Architecture Center

Geographical and logical growth of the World-Wide Web is accompanied by a fast technological development. Web can be successfully used as a platform for implementation of diverse applications. Distributed and collaborative systems are among the most challenging Web applications. TANGO is an integration platform which enables implementation of Web-based collaborative environments. The system provides means for fast integration of Web- and non-Web-applications into one multi-user collaborative systems. In this paper we describe the functional model, requirements, system design and certain implementation issues of the TANGO system.


Pcrc-Based Hpf Compilation, Guansong Zhang, Bryan Carpenter, Geoffrey C. Fox, Xiaoming Li Jan 1997

Pcrc-Based Hpf Compilation, Guansong Zhang, Bryan Carpenter, Geoffrey C. Fox, Xiaoming Li

Northeast Parallel Architecture Center

This paper describes an ongoing effort supported by ARPA PCRC (Parallel Compiler Runtime Consortium) project. In particular, we discuss the design and implementation of an HPF compilation system based on PCRC runtime. The approaches to issues such as directive analysis and communication detection are discussed in detail. The discussion includes fragments of code generated by the compiler.


Hpjava: Data Parallel Extensions To Java, Bryan Carpenter, Guansong Zhang, Geoffrey C. Fox, Xinying Li Jan 1997

Hpjava: Data Parallel Extensions To Java, Bryan Carpenter, Guansong Zhang, Geoffrey C. Fox, Xinying Li

Northeast Parallel Architecture Center

We outline an extension of Java for programming with distributed arrays. The basic programming style is Single Program Multiple Data (SPMD), but parallel arrays are provided as new language primitives. Further extensions include three distributed control constructs, the most important being a data-parallel loop construct. Communications involving distributed arrays are handled through a standard library of collective operations. Because the underlying programming model is SPMD programming, direct calls to MPI or other communication packages are also allowed in an HPJava program.


A Comparison Of Optimization Heuristics For The Data Mapping Problem, Nikos Chrisochoides, Nashat Mansour, Geoffrey C. Fox Jan 1997

A Comparison Of Optimization Heuristics For The Data Mapping Problem, Nikos Chrisochoides, Nashat Mansour, Geoffrey C. Fox

Northeast Parallel Architecture Center

In this paper we compare the performance of six heuristics with suboptimal solutions for the data distribution of two dimensional meshes that are used for the numerical solution of Partial Differential Equations (PDEs) on multicomputers. The data mapping heuristics are evaluated with respect to seven criteria covering load balancing, interprocessor communication, flexibility and ease of use for a class of single-phase iterative PDE solvers. Our evaluation suggests that the simple and fast block distribution heuristic can be as effective as the other five complex and computational expensive algorithms.


A System For Recognizing A Large Class Of Engineering Drawings, Yuhong Yu, Ashok Samal, Sharad C. Seth Jan 1997

A System For Recognizing A Large Class Of Engineering Drawings, Yuhong Yu, Ashok Samal, Sharad C. Seth

School of Computing: Faculty Publications

We present a system for recognizing a large class of engineering drawings characterized by alternating instances of symbols and connection lines. The class includes domains such as flowcharts, logic and electrical circuits, and chemical plant diagrams. The output of the system, a netlist identifying the symbol types and interconnections, may be used for design simulation or as a compact portable representation of the drawing. The automatic recognition task is divided into two stages: 1) Domain-independent rules are used to segment symbols from connection lines in the drawing image that has been thinned, vectorized, and preprocessed in routine ways. 2) A …


The Use Of Prime Numbers As An Effective Method Of Cryptology, Joshua Flynn Jan 1997

The Use Of Prime Numbers As An Effective Method Of Cryptology, Joshua Flynn

Honors Theses, 1963-2015

With the increasing amount of information transmitted over networks, there is a need to be able to keep this information from falling into the wrong hands. The method that has been used for the past couple of decades is that of cryptography. This paper gives an explanation of cryptography, as well as different alogorithms that are used to solve the problem. One unique thing about a couple of the algorithms is that they use properties provided by prime numbers. In particular, the RSA model, invented by Rivest, Shamir and Adelman, is one model which utilizes the theory that it is …


Just Which Reality Do You Mean? Users' Experiences Of Virtual Spaces, Woodrow Heath Pollack Jan 1997

Just Which Reality Do You Mean? Users' Experiences Of Virtual Spaces, Woodrow Heath Pollack

Senior Scholar Papers

Virtual Reality is a relatively new technology in the relatively young field of computer science. The design of Virtual Reality has only recently come into discussion, as well as the implications for this sort of design. I hope to determine how a user can work most efficiently and accurately in a Virtual World. By studying this, I hope to help in the standardization of Virtual Reality design.


Object-Oriented Development In Creating Software Systems, Brooke Frost Jan 1997

Object-Oriented Development In Creating Software Systems, Brooke Frost

Honors Theses, 1963-2015

Object-oriented development has become quite popular and well-known throughout the computer industry. There are three components that are a part of object-oriented development. One component is object-oriented analysis which involves the creation of an object-oriented model based on the application domain of the software system. The second component is object-oriented design which is when the programmers develop an object-oriented model based on the defined requirements for the software system. The last component is object-oriented programming which is the process of implementing the software system so it becomes a reality. Together these three components provide programmers with a beneficial tool in …


The Effects Of Network Latency On Multimedia Applications, James Beach Jan 1997

The Effects Of Network Latency On Multimedia Applications, James Beach

Honors Theses, 1963-2015

Network latency slows the response time of networks such as the Internet. This is an ever increasing problem as applications migrate towards interactive multimedia. To make multimedia applications viable across the Internet, the underlying data delivery structures of the Internet need to be changed. new technologies in network connections and data delivery schemes need to be further researched and implemented. Two cooperating technologies which demonstrate potential in delivering Internet multimedia applications are RealAudio systems and ATM (Asynchronous Transfer Mode) networks. Reducing network latency will help in bringing smooth, real-time audio and video to networked computers.


Genetic Algorithms: A Visual Search, Paul W. Jones Jan 1997

Genetic Algorithms: A Visual Search, Paul W. Jones

Honors Theses, 1963-2015

Genetic algorithms apply the biological principles of selection, mutation, and crossover to a population set containing individuals representing target solutions to a given problem. Using these principles genetic algorithms attempt to create a migration of the individuals in subsequent generations toward the optimal solution.

This project is an attempt to visually represent the progress of a genetic algorithm. The coordinate fitness program attempts to find the maximum or minimum value of a given function. It visually represents the progress of the algorithm by providing a plot of each individual in each generation in time. It is then possible to view …


The "Hoover" Project: Home Occupants Vehicular Electronic Reconnaissance, Kelvin Chan Jan 1997

The "Hoover" Project: Home Occupants Vehicular Electronic Reconnaissance, Kelvin Chan

SWITCH

The article explains telepresence, as well as its potential in safety and security, along with its traditional usage of traversing dangerous situations. This article describes a dystopian plan to place drones equipped with cameras and microphones in all homes in the Silicon Valley as a vehicle for telepresence. The data achieved through this method would also be stored into a public domain browser on the internet, free for anyone in the public to view, including larger corporations and the government. The idea behind this is the assimilation of data behind all cultures for understanding and to assist law enforcement in …


An Efficient Algorithm For Direct Computation Of Adjacent Block Coefficients In The Transformed Domain, Chaman Sabharwal, Brian Quandt Jan 1997

An Efficient Algorithm For Direct Computation Of Adjacent Block Coefficients In The Transformed Domain, Chaman Sabharwal, Brian Quandt

Computer Science Faculty Research & Creative Works

The current research in many areas of image processing involves operations performed in the compressed domain [Smith and Rowe 1993, Chang 93]. Compressed domain may be DCT, Wavelet, JPEG or MPEG etc. The algorithms for .these transformations may be used for information filtering such as feature extraction and edge detection. The image transformations such as compositing, occluding, and scaling may also be performed in the compressed domain. It is desirable to perform these operations on compressed data directly because the smaller size of data involves less computational complexity. The computation in the compressed domain eliminates the overhead of decoding the …


Improved Measurement Of The Bd0 -B̄D0 Oscillation Frequency, D. Buskulic, M. Thulasidas Jan 1997

Improved Measurement Of The Bd0 -B̄D0 Oscillation Frequency, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

The time dependence of B0 d {B 0 d oscillations is measured by the ALEPH experiment at LEP, using three techniques, two of which are updates of previous measurements. In all cases the charge of the decaying b quark and its decay time are measured in one hemisphere of the event; the quark charge at production is tagged mainly using the opposite hemisphere. The first method uses the charge correlation between a D and a lepton in the opposite hemisphere; if no lepton is present, the produced quark charge is determined from the hemisphere charges. In the second method, the …


Production Of Orbitally Excited Charm Mesons In Semileptonic B Decays, D. Buskulic, M. Thulasidas Jan 1997

Production Of Orbitally Excited Charm Mesons In Semileptonic B Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

A sample of 3.6 million hadronic Z decays recorded between 1991 and 1995 with the ALEPH detector at LEP is used to investigate semileptonic decays of B mesons into final states involving orbitally excited charm mesons. Topological vertex criteria are used to search for decays involving narrow D** states as well as wide D** resonances and non-resonant D(*)π final states. The sum of the branching ratios for these processes is measured to be ${⤪ Br}({⩈erline {⤪ B}}⌝ghtarrow {⤪ D}≪ ⫑l^{-}{⩈erline v}) + {⤪ Br}({⩈erline {⤪ B}}⌝ghtarrow {⤪ D}^{⇒t}≪ ⫑l^{-}{⩈erline v})↦op =(2.26 pm 0.29({⤪ stat}) pm 0.33({⤪ syst}))%,$which accounts for a …


Transverse Momentum Correlations In Hadronic Z Decays, D. Buskulic, M. Thulasidas Jan 1997

Transverse Momentum Correlations In Hadronic Z Decays, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

Using data obtained with the ALEPH detector at the Z resonance, a measure based on transverse momentum is shown to exhibit a correlation between the two halves of a hadronic event which cannot be explained by energy-momentum conservation, flavour conservation, the imposition of an event axis or imperfect event reconstruction. Two possible interpretations based on existing Monte Carlo models are examined: a) ARIADNE, with the correlation forming early in the parton shower and with the transition from partons to hadrons playing only a minor part; b) JETSET, with the correlation forming at the fragmentation stage. A correlation technique based on …


Integrated Queries To Existing Bibliographic And Structured Databases, Ee Peng Lim, Ying Lu Jan 1997

Integrated Queries To Existing Bibliographic And Structured Databases, Ee Peng Lim, Ying Lu

Research Collection School Of Computing and Information Systems

It is widely accepted that future digital library applications have to be built upon different kinds of database servers to draw upon different forms of data, including bibliographic, text, multimedia, and structured data. In this paper, the problem of integrating existing public bibliographic databases and structured databases which reside at different locations in the network is addressed. Although bibliographic data is semistructured, its attribute set is often determined by an international standard known as MARC. To unify bibliographic and structured data, the well-known SQL was extended to model bibliographic related attributes and queries. In particular, a new data type was …


Analysis Of Digital Logic Schematics Using Image Recognition, James A. Giles Jan 1997

Analysis Of Digital Logic Schematics Using Image Recognition, James A. Giles

UNF Graduate Theses and Dissertations

This thesis presents the results of research in the area of automated recognition of digital logic schematics. The adaptation of a number of existing image processing techniques for use with this kind of image is discussed, and the concept of using sets of tokens to represent the overall drawing i s explained in detail. Methods are given for using tokens to describe schematic component shapes, to represent the connections between components, and to provide sufficient information to a parser so that an equation can be generated. A Microsoft Windows-based test program which runs under Windows 95 or Windows NT has …


Hardware Interfacing In The Broadcast Industry Using Simple Network Management Protocol (Snmp), Walter H. Schuller Jr. Jan 1997

Hardware Interfacing In The Broadcast Industry Using Simple Network Management Protocol (Snmp), Walter H. Schuller Jr.

UNF Graduate Theses and Dissertations

Communication between various broadcast equipment plays a major role in the daily operation of a typical broadcast facility. For example, editing equipment must interface with tape machines, production switchers must interface with font generators and video effect equipment, and satellite ground controllers must interface with satellite dishes and receivers. Communication between these devices may be a simple hardware handshake configuration or a more elaborate software based communications via serial or parallel interfacing. This thesis concerns itself with the software interfacing needed to allow various dissimilar types of equipment to communicate, and therefore, interface with each other. The use of Simple …