Digital Commons Network^™

Elimination Of All-Optical Cycles In Wavelength-Routed Optical Networks, Jason Iness, Byrav Ramamurthy, Biswanath Mukherjee, Krishna Bala

School of Computing: Faculty Publications

A transparent (wide-area) wavelength-routed optical network may be constructed by using wavelength cross-connect switches connected together by fiber to form an arbitrary mesh structure. The network is accessed through electronic stations that are attached to some of these cross-connects. These wavelength cross-connect switches have the property that they may configure themselves into unspecified states. Each input port of a switch is always connected to some output port of the switch whether or not such a connection is required for the purpose of information transfer. Due to the presence of these unspecified states, there exists the possibility of setting up unintended …

On The Use Of The Complexity Index As A Measure Of Complexity In Activity Networks, Bert De Reyck, Willy Herroelen

Research Collection Lee Kong Chian School Of Business

A large number of optimal and suboptimal procedures have been developed for solving combinatorial problems modeled as activity networks. The need to differentiate between easy and hard problem instances and the interest in isolating the fundamental factors that determine the computing effort required by these procedures, inspired a number of researchers to develop various complexity measures. In this paper we investigate the relation between the hardness of a problem instance and the topological structure of its underlying network, as measured by the complexity index. We demonstrate through a series of experiments that the complexity index, defined as the minimum number …

On Mobile Systems And Disconnected Browsing Of Distributed Information, Anupam Joshi, Sanjiva Weerawarana, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Automatic Identification Of Icosahedral Virus Particles In Electron Micrographs, Ioana Maria Martin, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

A Peak Finding Strategy For Multi- Dimensional Scalar Fields With Applications To X-Ray Crystallography, Calin R. Costian, Ioana M. Boier Martin, Dan C. Marinescu, Mikhail J. Atallah

Department of Computer Science Technical Reports

No abstract provided.

Study Of The B0sb0s Oscillation Frequency Using D-S ℓ+ Combinations In Z Decays, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

A lower limit on the oscillation frequency of the B s 0 B s 0 system is obtained from approximately four million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1995. Leptons are combined with opposite sign D s − candidates reconstructed in seven different decay modes as evidence of semileptonic B s 0 decays. Criteria designed to ensure precise proper time reconstruction select 277D s − ℓ + combinations. The initial state of these B s 0 candidates is determined using an algorithm optimized to efficiently utilise the tagging information available for each event. …

Supporting Search For Reusable Software Objects, T. Isakowitz, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

Prior research has shown that achieving high levels of software reuse in the presence of repository and object-based computer-aided software engineering (CASE) development methods presents interesting human, managerial and technical challenges. This article presents research that seeks to enhanced software development performance through reuse. We propose automated support for developers who search large repositories for the appropriate reusable software objects. We characterize search for repository objects in terms of a multistage model involving screening, identification, and the subsequent choice between new object construction or reusable object implementation. We propose automated support tools, including ORCA, a software Object Reuse Classification Analyzer, …

Measurement Of Hadron And Lepton-Pair Production From E+E- Annihilation At Centre-Of-Mass Energies Of 130 And 136 Gev, Buskulic, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Knowledge Discovering For Document Classification Using Tree Matching In Texpros, Ching-Song Wei

Dissertations

This dissertation describes a knowledge-based system for classifying documents based upon the layout structure and conceptual information extracted from the content of the document. The spatial elements in a document are laid out in rectangular blocks which are represented by nodes in an ordered labelled tree, called the "layout structure tree" (L-S Tree). Each leaf node of a L-S Tree points to its corresponding block content. A knowledge Acquisition Tool (KAT) is devised to create a Document Sample Tree from L-S Tree, in which each of its leaves contains a node content conceptually describing its corresponding block content. Then, applying …

Integrating Hypertext With Information Systems Through Dynamic Mapping, Jiangling Wan

Dissertations

This dissertation presents a general hypertext model (GHMI) supporting integration of hypertext and information systems through dynamic mapping. Information systems integrated based on this model benefit from hypertext function-alities (such as linking, backtracking, history, guided tours, annotations, etc.) while preserving their own computation capabilities. Although systems supporting integration of hypertext and interface-oriented information systems do exist in hypertext literature, there is no existing model or system effectively supporting integration of hypertext and computation-oriented information systems. GHMI makes its major contributions by both extending and specifying the well-known Dexter Hypertext Reference Model. GHMI extends the Dexter model to overcome its limitations. …

Theory And Design Of Portable Parallel Programs For Heterogeneous Computing Systems And Networks, Ying-Chieh Wu

Dissertations

A recurring problem with high-performance computing is that advanced architectures generally achieve only a small fraction of their peak performance on many portions of real applications sets. The Amdahl's law corollary of this is that such architectures often spend most of their time on tasks (codes/algorithms and the data sets upon which they operate) for which they are unsuited. Heterogeneous Computing (HC) is needed in the mid 90's and beyond due to ever increasing super-speed requirements and the number of projects with these requirements. HC is defined as a special form of parallel and distributed computing that performs computations using …

A Brief Introduction To Formal Methods, Paul E. Black, Kelly M. Hall, Michael D. Jones, Trent N. Larson, Phillip J. Windley

Faculty Publications

As hardware designs grow in size and complexity, current design methods are proving less adequate. Current methods for specification, design, and test are typically empirical or informal, that is, they are based on experience and argument. Formal methods are solidly based on mathematical logic systems and precise rules of inference. Formal methods offer a discipline which complements current methods so designers can successfully meet the demand for high performance systems. Formal methods covers a broad and diverse set of techniques aimed at improving computer correctness. This paper explains the role of specifications and implementation models in formal methods, and different …

Mobile Agents For Mobile Computing, Robert Gray, David Kotz, Saurab Nog, Daniela Rus, George Cybenko

Computer Science Technical Reports

Mobile agents are programs that can move through a network under their own control, migrating from host to host and interacting with other agents and resources on each. We argue that these mobile, autonomous agents have the potential to provide a convenient, efficient and robust programming paradigm for distributed applications, particularly when partially connected computers are involved. Partially connected computers include mobile computers such as laptops and personal digital assistants as well as modem-connected home computers, all of which are often disconnected from the network. In this paper, we describe the design and implementation of our mobile-agent system, Agent Tcl, …

Probabilistic Analysis Of The Median Rule: Asymptotics And Applications, Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

The solution of integer optimization problems by relaxation methods consists of three parts. First, the discrete problem is converted into a continuous optimization problem, which is generally more tractable. Second, the relaxed problem is solved efficiently, yielding a optimal solution in the continuous space. Finally, an assignment procedure is used to map this solution to a "suitable" discrete solution. One heuristic - we call it the relaxation heuristic - that often guides the choice and design of assignment algorithms is: "given a continuous optimal solution, the corresponding integer optimal solution is likely to be nearby" (with respect to some well …

The Use Of Non-Commutative Algebra In Cryptographically Secure Pseudo-Random Number Generators, Brian M. Mckeever

Honors Theses

This thesis begins with a general overview of pseudo-random number generators and some of their applications. This thesis then describes their applications to cryptography, and some additional requirements imposed by cryptography. This thesis then provides an introduction to the ring of quaternions, and discusses how they can be included in pseudo-random number generators. Finally, this thesis provides a description of the performance of these generators.

Dartflow: A Workflow Management System On The Web Using Transportable Agents, Ting Cai, Peter A. Gloor, Saurab Nog

Computer Science Technical Reports

Workflow management systems help streamline business processes and increase productivity. This paper describes the design and implementation of the DartFlow workflow management system. DartFlow uses Web-browser embedded Java applets as its front end and transportable agents as the backbone. While Java applets provide a safe and platform independent GUI, the use of transportable agents makes DartFlow highly flexible and scalable. This paper describes the design and implementation of DartFlow, as well as a workflow application that exploits DartFlow's agent-based design.

The Galley Parallel File System, Nils Nieuwejaar, David Kotz

Computer Science Technical Reports

Most current multiprocessor file systems are designed to use multiple disks in parallel, using the high aggregate bandwidth to meet the growing I/O requirements of parallel scientific applications. Many multiprocessor file systems provide applications with a conventional Unix-like interface, allowing the application to access multiple disks transparently. This interface conceals the parallelism within the file system, increasing the ease of programmability, but making it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. In addition to providing an insufficient interface, most current multiprocessor file systems are optimized for a different …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 5, May 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Dynamic Scheduling Of Process Groups, Kuei Yu Wang, Dan C. Marinescu, Octavian F. Carbunar

Department of Computer Science Technical Reports

No abstract provided.

Energy Formulations Of A-Splines, Chandrajit L. Bajaj, Jindon Chen, Robert J. Holt, Arun N. Netravali

Department of Computer Science Technical Reports

No abstract provided.

A Young-Eidson's Type Algorithm For Complex P-Cyclic Sor Spectra, S. Galanis, A. Hadijimos, D. Noutsos

Department of Computer Science Technical Reports

No abstract provided.

A Color-Based Technique For Measuring Visible Loss For Use In Image Data Communication, Melliyal Annamalai, Aurobindo Sundaram, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Front-Tracking Finite Difference Methods For The American Option Valuation Problem, K. N. Pantazopoulos, S. Zhang, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Integrated Multimedia Timeline Of Medical Images And Data For Thoracic Oncology Patients, Denise R. Aberle, John David N. Dionisio, Michael F. Mcnitt-Gray, Ricky K. Taira, Alfonso F. Cárdenas, Jonathan G. Goldin, Kathleen Brown, Robert A. Figlin, Wesley W. Chu

Computer Science Faculty Works

A prototype multimedia medical database has been developed to provide image and textual data for thoracic oncology patients undergoing treatment of advanced malignancies. The database integrates image data from the hospital pieture archiving and communication system with textual reports from the radiology information system, alphanumeric data contained in the hospital information system, and other electronic medical data. The database presents information in a timeline format and also contains visualization programs that permit the user to view and annotate radiographic measurements in tabular or graphic form. The database provides an efficient and intuitive display of the changing status of oncology patients. …

New Methods In Finite First-Order Model Search, Olga Shumsky, Fikret Ercal, Ralph W. Wilkerson

Computer Science Technical Reports

An automated first-order theorem prover, armed with appropriate strategies, will find a proof of a true conjecture, but will, in theory, run indefinitely if no proof exists. In reality, if no proof exists, the execution will be terminated by user-defined constraints, such as running time or memory usage limit. In this case the the question of validity of the conjecture remains unanswered. An automated first-order model generator gives one the ability to find counterexamples, if any exist, showing that the conjecture is invalid. A model generator also helps find the illustrations of previously proved theorems. It can be viewed as …

Low-Degree Spanning Trees Of Small Weight, Samir Khuller, Balaji Raghavachari, Neal Young

Dartmouth Scholarship

Given n points in the plane, the degree-K spanning-tree problem asks for a spanning tree of minimum weight in which the degree of each vertex is at most K. This paper addresses the problem of computing low-weight degree-K spanning trees for $K > 2$. It is shown that for an arbitrary collection of n points in the plane, there exists a spanning tree of degree 3 whose weight is at most 1.5 times the weight of a minimum spanning tree. It is shown that there exists a spanning tree of degree 4 whose weight is at most 1.25 times …

Parametric Kinematic Tolerance Analysis Of Planar Mechanisms, Elisha Sacks, Leo Joskowicz

Department of Computer Science Technical Reports

No abstract provided.

Adaptive Integration Of Audio And Visual Information Using Discrete And Semi-Continuous Hidden Markov Models In Audiovisual Automatic Speech Recognition, Qin Su

Electrical & Computer Engineering Theses & Dissertations

An audiovisual semi-continuous hidden Markov model (HMM)-based Automatic Speech Recognition (ASR) system and an improved method of integrating audio and visual information in an audiovisual discrete HMM-based ASR system are investigated.

In the audiovisual discrete HMM, an adaptive integration formulation is employed, which incorporates the integration into the HMM at a pre-categorical stage. A visual weighting parameter is determined automatically, which allows the relative contribution of audio and visual information to be adjusted adaptively. Using an adaptive weight, the accuracy increased by 13% compared to the same model with no adaptive weight.

The semi-continuous HMM is a class of models …

Wheels: An Automated Program Analysis Tool, Aggie Sun, Bruce Mcmillin

Computer Science Technical Reports

The understanding of program behavior is becoming vitally more important now that software is becoming an integral part of industry and everyday life. However, even the best documented code is often not sufficient enough to completely and correctly relay the actual program behavior. The problem lies beyond being familiar with the programming language and is hidden in the complex mathematics which govern the program's behavior. This behavior is not easily detected and varies from one program to the next. We propose a method for describing program behavior using two general properties of iterative programs: feasibility and progress. This method can …

Categorization Of Programs Using Neural Networks, Franz J. Kurfess, Lonnie R. Welch

Computer Science and Software Engineering

This paper describes some experiments based on the use of neural networks for assistance in the quality assessment of programs, especially in connection with the reengineering of legacy systems. We use Kohonen networks, or self-organizing maps, for the categorization of programs: programs with similar features are grouped together in a two-dimensional neighbourhood, whereas dissimilar programs are located far apart. Backpropagation networks are used for generalization purposes: based on a set of example programs whose relevant aspects have already been assessed, we would like to obtain an extrapolation of these assessments to new programs. The basis for these investigation is an …