Digital Commons Network^™

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 …

Stochastic Approximation Methods For Systems Over An Infinite Horizon, Harold J. Kushner, Felisa Vázquez-Abad

Publications and Research

The paper develops efficient and general stochastic approximation (SA) methods for improving the operation of parametrized systems of either the continuous- or discrete-event dynamical systems types and which are of interest over a long time period. For example, one might wish to optimize or improve the stationary (or average cost per unit time) performance by adjusting the systems parameters. The number of applications and the associated literature are increasing at a rapid rate. This is partly due to the increasing activity in computing pathwise derivatives and adapting them to the average-cost problem. Although the original motivation and the examples come …

Teaching Ethical Issues In Computer Science: What Worked And What Didn't, Kay G. Schulze, Frances Grodzinsky

School of Computer Science & Engineering Faculty Publications

It is the role of computer science educators to ensure that students have a firm foundation in the social and ethical issues of the discipline.

A System For Structured Management Of Hypermedia Resources For The World Wide Web, Kevin L. Marlowe

Computer Science Theses & Dissertations

The World Wide Web (WWW) is arguably the preferred method for disseminating information across the Internet. Most of the work to support the advancement of WWW technology has focused on servers used in storing and retrieving information, browsers for viewing this information, and editors or filters for creating the information.

One area which has received little attention is that of actually managing this information at the local host. This thesis describes the development of a means for organizing local data prior to its publishing on the WWW, a method for gathering local pages together and preparing them for distribution, and …

R-By-C Crozzle: An Np-Hard Problem, Michelle Gower, Ralph W. Wilkerson

Computer Science Faculty Research & Creative Works

In an Australian Magazine, a Monetary Prize is Awarded to the Person with the Best Answer to a Word Puzzle Called a Crozzle. the Placement of Words into a Ten by Fifteen Grid Obtaining the Highest Score is the Best Answer. Various Search Techniques Have Been Employed to Solve This Problem, Yet No One Has Shown Whether There is a Polynomial-Time Algorithm to Find the Best Crozzle. This Paper Creates a Similar Word Puzzle, Called R-By-C Crozzle, by Lifting the Constraint on the Grid Size. R-By-C Crozzle is Not in NP, But There Exists a Polynomial Reduction to It from …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 2, February 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Automatic Generation Of 3d Cad Models, Chandrajit L. Bajaj, Fausto Bernardini, Jindon Chen, Daniel R. Schikore

Department of Computer Science Technical Reports

No abstract provided.

On Gang Scheduling And Demand Paging, Dan C. Marinescu, Kuei Yu Wang

Department of Computer Science Technical Reports

No abstract provided.

Web//Ellpack: A Networked Computing Service On The World Wide Web, Sanjiva Weerawarana, Elias N. Houstis, John R. Rice, Margaret G. Gaitatzes, Shahani Markus

Department of Computer Science Technical Reports

No abstract provided.

A Precise Measurement Of The Average B Hadron Lifetime, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

An improved measurement of the average b hadron lifetime is performed using a sample of 1.5 million hadronic Z decays, collected during the 1991–1993 runs of ALEPH, with the silicon vertex detector fully operational. This uses the three-dimensional impact parameter distribution of lepton tracks coming from semileptonic b decays and yields an average b hadron lifetime of 1.533 ± 0.013 ± 0.022 ps.

Entity Identification In Database Integration, Ee Peng Lim, Jaideep Srivastava, Satya Prabhakar, James Richardson

Research Collection School Of Computing and Information Systems

The objective of entity identification is to determine the correspondence between objective instances from more than one database. This paper examines the problem at the instance level assuming that schema level heterogeneity has been resolved a priori. Soundness and completeness are defined as the desired properties of any entity-identification technique. To achieve soundness, a set of identity and distinctness rules have to be established for the entities in the integrated world. We then propose the use of extended key, which is the union of keys (and possibly other attributes) from the relations to be matched, and its corresponding identity rule …

Identifying And Exploiting Concurrency In Object-Based Real-Time Systems, Guohui Yu

Dissertations

The use of object-based mechanisms, i.e., abstract data types (ADTs), for constructing software systems can help to decrease development costs, increase understandability and increase maintainability. However, execution efficiency may be sacrificed due to the large number of procedure calls, and due to contention for shared ADTs in concurrent systems. Such inefficiencies are a concern in real-time applications that have stringent timing requirements. To address these issues, the potentially inefficient procedure calls are turned into a source of concurrency via asynchronous procedure calls (ARPCs), and contention for shared ADTS is reduced via ADT cloning. A framework for concurrency analysis in object-based …

Transportable Information Agents, Robert Gray, Daniela Rus, David Kotz

Computer Science Technical Reports

We have designed and implemented autonomous software agents. Autonomous software agents navigate independently through a heterogeneous network. They are capable of sensing the network configuration, monitoring software conditions, and interacting with other agents. Autonomous agents are implemented as transportable programs, e.g., programs that are capable of suspending execution, moving to a different machine, and starting from where they left off. We illustrate the intelligent behavior of autonomous agents in the context of distributed information-gathering tasks.

A Library-Based Approach To Task Parallelism In A Data-Parallel Language, Ian Foster, David R. Kohr, Rakesh Krishnaiyer, Alok Choudhary

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

The data-parallel language High Performance Fortran (HPF) does not allow efficient expression of mixed task/data-parallel computations or the coupling of separately compiled data-parallel modules. In this paper, we show how these common parallel program structures can be represented, with only minor extensions to the HPF model, by using a coordination library based on the Message Passing Interface (MPI). This library allows data-parallel tasks to exchange distributed data structures using calls to simple communication functions. We present microbenchmark results that characterize the performance of this library and that quantify the impact of optimizations that allow reuse of communication schedules in common …

A Unified Tiling Approach For Out-Of-Core Computations, Rajesh Bordawekar, Alok Choudhary, J. Ramanujam, Mahmut Kandemir

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

This paper describes a framework by which an out-of-core stencil program written in a data-parallel language can be translated into node programs in a distributed-memory message-passing machine with explicit I/O and communication. We focus on a technique called Data Space Tiling to group data elements into slabs that can fit into memories of processors. Methods to choose legal tile shapes under several constraints and deadlock-free scheduling of tiles are investigated. Our approach is unified in the sense that it can be applied to both FORALL loops and the loops that involve flow-dependences.

The Isomorphism Conjecture Fails Relative To A Random Oracle, Stuart A. Kurtz, Stephen R. Mahaney, James S. Royer

Electrical Engineering and Computer Science - All Scholarship

Berman and Hartmanis [BH77] conjectured that there is a polynomialtime computable isomorphism between any two languages complete for NP with respect to polynomial-time computable many-one (Karp) reductions. Joseph and Young [JY85] gave a structural definition of a class of NP-complete sets---the k-creative sets---and defined a class of sets (the K k f 's) that are necessarily k-creative. They went on to conjecture that certain of these K k f 's are not isomorphic to the standard NP-complete sets. Clearly, the Berman--Hartmanis and Joseph--Young conjectures cannot both be correct. We introduce a family of strong one-way functions, the scrambling functions. If …

Array Decompositions For Nonuniform Computational Environments, Maher Kaddoura, Sanjay Ranka, Albert Wang

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

Two-dimensional arrays are useful in a large variety of scientific and engineering applications. Parallelization of these applications requires the decomposition of array elements among different machines. Several data-decomposition techniques have been studied in the literature for machines with uniform computational power. In this paper we develop new methods for decomposing arrays into a cluster of machines with nonuniform computational power. Simulation results show that our methods provide superior decomposition over naive schemes.

Hierarchical Growing Cell Structures, Vanco Burzevski, Chilukuri K. Mohan

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

We propose a hierarchical self-organizing neural network ("HiGS") with adaptive architecture and simple topological organization. This network combines features of Fritzke's Growing Cell Structures and traditional hierarchical clustering algorithms. The height and width of the tree structure depend on the user-specified level of error desired, and the weights in upper layers of the network do not change in later phases of the learning algorithm. Parameters such as node deletion rate are adaptively modified by the learning algorithm.

Cooperative Assistance For Remote Robot Supervision, Robin R. Murphy, Erika Rogers

Computer Science and Software Engineering

This paper describes current work on a cooperative tele-assistance system for semi-autonomous control of mobile robots. This system combines a robot architecture for limited autonomous perceptual and motor control with a knowledge-based operator assistant which provides strategic selection and enhancement of relevant data. It extends recent developments in artificial intelligence in modeling the role of visual interactions in problem solving for application to an interface permitting the human and remote to cooperate in cognitively demanding tasks such as recovering from execution failures, mission planning, and learning. The design of the system is presented, together with a number of exception-handling scenarios …

A Study Of Visual Reasoning In Medical Diagnosis, Erika Rogers

Computer Science and Software Engineering

The purpose of this paper is to describe experimental work conducted in the area of diagnostic radiology,with an emphasis on how perception and problem solving interact in this type of task. This work was part of a larger project whose goals included the development of an information-processing model of visual interaction,and the subsequent design of an intelligent cooperative assistant for this domain.

Verbal protocol data was collected from eight radiologists (six residents and two experts) while they examined seven different computer-displayed chest x-rays. A brief overview of the methodology and analysis techniques is presented, together with specific results from one …