Digital Commons Network^™

Visual Presentation Of Software Specifications And Designs, Gruia-Catalin Roman, Delbert Hart, Charles Calkins

All Computer Science and Engineering Research

Formal methods hold the promise for high dependability in the design of critical software. However, software engineers who employ formal methods need to communicate their design decisions to users, customers, managers, and collegues who may not be in a position to acquire a full understanding of the formal notation being used. Visualizations derived from formal specifications and designs must be able to convey the required information precisely and reliably without the use of formal notation. This paper discusses a design methodology which attempts to integrate a design methodology based upon specification and program refinement with a state-of-the-art approach to rapid …

Performance Comparison Of Asynchronous Adders, Mark A. Franklin, Tienyo Pan

All Computer Science and Engineering Research

In asynchronous systems, average function delays principally govern overall throughput. This paper compares the performance of six adder designs with respect to their average delays. Our results show that asynchronous addres (32 or 64-bits) with a hybrid structure (e.g., carry-select addres) run 20-40% faster than simple ripple-carry addres. Hybrid adders also outperform high-cost, strictly synchronous conditional-sum adders.

An Application-Oriented Error Control Scheme For High Speed Networks, Fengmin Gong, Gurudatta Parulkar

All Computer Science and Engineering Research

Many new network applications demand interprocess communication (IPC) services that are not supported by existing transport protocol mechanisms. Large bandwidth-delay products of high-speed networks also render the existing control mechanisms such as flow and error control less efficient. In particular, new error control schemes that can provide variable degrees of error recovery according to the applications requirements are needed. This paper presents the design, evaluation, and implementation of an application-oriented error control scheme that is aimed at supporting efficient IPC in high-speed networking environments. Our results show that the proposed error control scheme allows effective control of trade-off between the …

Practical Methods For Approximating Shortest Paths On A Convex Polytope In R3, John Hershberger, Subhash Suri

All Computer Science and Engineering Research

We propose a n extremely simple approximation scheme for computing shortest paths on the surface of a convex polytope in three dimensions. Given a convex polytope P with n vertices and two points p,q on its surface, let dp (p,q) denote the shortest path distance between p and q on the surface of P. Our algorithm produces a path of length at most 2 × dp(p,q) in time O(n). Extending this results, we can also compute ana pproximation of the shortest path tree rooted at an arbitrary point χ Є P in time O(n log n). In the approximate tree, …

Speculative Computation: Overcoming Communication Delays In Parallel Algorithms, Vasudha Govindan, Mark A. Franklin

All Computer Science and Engineering Research

Communication latencies and delays are a major source of performance degradation in parallel computing systems. It is importnat to "mask" these communication delays by overlapping them with useful computation in order to obtain good parallel performance. This paper proposes speculative computation as a technique to mask communication latencies. Speculative computation is discussed in the context of synchronous iterative algorithms. Processors speculate the contents of messages that are not hyet received and perform computation based on the speculated values. When the messages are received, they are compared with the speculated values and, if the error is unacceptable, the resulitng computation is …

An Incremental Distributed Algorithm For Computing Biconnected Components, Bala Swaminathan, Kenneth J. Goldman

All Computer Science and Engineering Research

This paper describes a distributed algorithm for computing the biconnected components of a dynamically changing graph. Our algorithm has a worst case communication complexity of O(b + c) messages for an edge insertion and O(b' + c) messages for an edge removal, and a worst case time complexity of O(c) for both operations, where c is the maximum number of biconnected components in any of the connected components during the operation, b is the number of nodes in the biconnected component containing the new edge, and bprime is the number of nodes in the biconnected component in which the update …

An Evaluation Of The Pavane Visualization System, Kenneth C. Cox, Gruia-Catalin Roman

All Computer Science and Engineering Research

The Pavane program visualization system is an implementation of the declarative paradigm of visualization. After a brief report on the status of the Pavane implementation, we present the results of an evaluation of the usability of Pavane. This evaluation is based on the use of Pavane by its developers to construct program visualizations, on its use in a classroom setting as a tool for examining executing programs, and on its application to some simple scientific visualizations.

Learning And Teaching Of Boolean And Geometric Classes, H. David Mathias

All Computer Science and Engineering Research

We consider the concept classes of DNF formulas and unions of discretized, axis-parallel d-dimensional boxes in discretized d-dimensional space with respect to several different learning models. In the model of learning with queries we present an algorithm to learn unions of boxes. We introduce a model of teaching that prevents illicit communication between the teacher and the leaner but that captures the intuitive aspect of teaching: a learner should perform at least as well with a cooperative teacher as with an adversarial teacher. We propose the study of teaching of DNF formulas and unions of boxes in this model. We …

Distributed Multimedia Systems Research Prospectus, Jonathan Turner

All Computer Science and Engineering Research

Distributed multimedia computing and communiation systems combine computer systems, networks and distributed software to facilitate applications that enable and enhance collaborative work, direct interpersonal communication, remote access to information and real-time presentation of information from a variety of sources. Over the next decade, we expect such systems to become central to the infrastructure of our increasingly information-driven society. This prospectus describes a program of research being pursued within the Computer and Communications Research Center of Washington University and the Departments of Computer Science and Electrical Engineering. This program seeks to promote the creation of effective distributed multimedia systems and develop …

Connection Management In Reconfigurable Distributed Systems, Bala Swaminathan

All Computer Science and Engineering Research

The Programmer's Playground takes a new approach to simplifying and supporting the construction of distributed applications. The approach, called I/O abstraction, separates the description of a system's communication structure from the descriptions of its computational components so that software modules written in existing programming languages cna be integrated flexibly and dynamically by both programmers and end-users. This separation is achieved by estabishing logical connectinos among the data interfaces of independent software modules. The logical connections provide a uniform high-level view of communication for both discrete and continuous data. The I/O abstraction approach inherits ideas from the I/O automaton model, a …

Proposal For Research Distribution Of Gigabit Network Technology, Jonathan Turner

All Computer Science and Engineering Research

In 1993, APRA funded a major program at Washingotn University to create gigabit networking technology and create a gigabit testbed based on this technology. This program is now nearing the end of its first year and is making excellent proress towards its research and technical objectives. This note a proposes a program that would lead to the export of this technology to research groups in networking and gigabit applications with an interest in using it to further their own research activities.

Nonlinear Transient Dynamics Of Flexible Robots, Mohamed Fouad Abdel Wahab

Archived Theses and Dissertations

No abstract provided.

The World Wide Web And Technology Transfer At Nasa Langley Research Center, Michael L. Nelson, David J. Bianco

Computer Science Faculty Publications

NASA Langley Research Center (LaRC) began using the World Wide Web (WWW) in the summer of 1993, becoming the first NASA installation to provide a Center-wide home page. This coincided with a reorganization of LaRC to provide a more concentrated focus on technology transfer to both aerospace and non-aerospace industry. Use of the WWW and NCSA Mosaic not only provides automated information dissemination, but also allows for the implementation, evolution and integration of many technology transfer applications. This paper describes several of these innovative applications, including the on-line presentation of the entire Technology Opportunities Showcase (TOPS), an industrial partnering showcase …

Electronic Document Distribution: Design Of The Anonymous Ftp Langley Technical Report Server, Michael L. Nelson, Gretchen L. Gottlich

Computer Science Faculty Publications

An experimental electronic dissemination project, the Langley Technical Report Server (LTRS), has been undertaken to determine the feasibility of delivering Langley technical reports directly to the desktops of researchers worldwide. During the first six months, over 4700 accesses occurred and over 2400 technical reports were distributed. This usage indicates the high level of interest that researchers have in performing literature searches and retrieving technical reports at their desktops. The initial system was developed with existing resources and technology. The reports are stored as files on an inexpensive UNIX workstation and are accessible over the Internet. This project will serve as …

World Wide Web Implementation Of The Langley Technical Report Server, Michael L. Nelson, Gretchen L. Gottlich, David J. Bianco

Computer Science Faculty Publications

On January 14, 1993, NASA Langley Research Center (LaRC) made approximately 130 formal, 'unclassified, unlimited' technical reports available via the anonymous FTP Langley Technical Report Server (LTRS). LaRC was the first organization to provide a significant number of aerospace technical reports for open electronic dissemination. LTRS has been successful in its first 18 months of operation, with over 11,000 reports distributed and has helped lay the foundation for electronic document distribution for NASA. The availability of World Wide Web (WWW) technology has revolutionized the Internet-based information community. This paper describes the transition of LTRS from a centralized FTP site to …

A Strategy For Electronic Dissemination Of Nasa Langley Technical Publications, Donna G. Roper, Mary K. Mccaskill, Scott D. Holland, Joanne L. Walsh, Michael L. Nelson, Susan L. Adkins, Manjula Y. Ambur, Bryan A. Campbell

Computer Science Faculty Publications

To demonstrate NASA Langley Research Center's relevance and to transfer technology to external customers in a timely and efficient manner, Langley has formed a working group to study and recommend a course of action for the electronic dissemination of technical reports (EDTR). The working group identified electronic report requirements (e.g., accessibility, file format, search requirements) of customers in U.S. industry through numerous site visits and personal contacts. Internal surveys were also used to determine commonalities in document preparation methods. From these surveys, a set of requirements for an electronic dissemination system was developed. Two candidate systems were identified and evaluated …

Bachelor Of Science Degree In Computer Science, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Doctoral Programs Computer Info Systems, Info Science, Info Sytems, Computer Science, Computing Technology In Education 1994, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Ms Computer Science, Ms Computer Information Systems, Ms Computer Technology In Education, Ms Management Info System, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Immittance Spectroscopy Of Smart Components And Novel Devices, Mohammad Anwarul Alim, Sanjida Khanam, Martin A. Seitz

Electrical and Computer Engineering Faculty Research and Publications

AC small-signal immittance spectroscopy is employed as a viable tool to demonstrate electrical characterization, performance improvement, and quality assurance issues of smart materials-based components and novel devices. The variation in the ac response, complemented via dc measurements within a range of tolerating temperature, delineates competing phenomena occurring in the microstructures of these engineering material systems. The results are presented in a generic manner with possible explanations on the mechanisms for two selected Debye-like (nearly ideal) and non-Debye (non-ideal) low-capacitance resistors. This spectroscopic approach allows systematic development of a representative equivalent circuit, considered to be the characteristic of the devices and …

An Expert System-Based Approach To Hospitality Company Diagnosis, Andrew Balfe, Peter O'Connor, Ciaran Mcdonnell

Conference papers

This paper describes the development of a prototype Expert System-based Analysis and Diagnostic (ESAD) package for the Hotel and Catering Industry. This computerised tool aids the hospitality manager in methodically scrutinising the hotel unit and environment, combining key information with systematic reasoning. The system searches through its extensive knowledge base, investigating complicated relationships. The number of possibilities considered is increased which will broaden the depth and breadth of the analysis and therefore should improve the quality of the managers decision making.

Measurement Of Cabibbo-Suppressed Decays Of The Τ Lepton, Battle, M.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Observation Of A New Charmed Strange Meson, Kubota, Y.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Precision Measurement Of The Ds*+-Ds+ Mass Difference, Brown, D.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

We have measured the vector-pseudoscalar mass splitting M(D*+s)-M(D+s)=144.22±0.47±0.37 MeV significantly more precisely than the previous world average. We minimize the systematic errors by also measuring the vector-pseudoscalar mass difference M(D*0)-M(D0) using the radiative decay D*0→D0γ, obtaining [M(D*+s)-M(D+s)]-[M(D*0)-M(D0)] =2.09±0.47±0.37 MeV. This is then combined with our previous high-precision measurement of M(D*0)-M(D0), which used the decay D*0→D0π0. We also measure the mass difference M(D+s)-M(D+)=99.5±0.6±0.3 MeV, using the φπ+ decay modes of the D+s and D+ mesons.

An Examination Of The Relationships Among Learning Style, Attitudes, And Outcomes Of Computer-Assisted Instruction, Daniel Glen Wilson

Dissertations and Theses @ UNI

This research was based upon a hypothesized AptitudeTreatment Interaction (ATI). More specifically, the research investigated the relationships between student learning style (aptitude) and student outcomes with computer-assisted instruction (treatment). These outcomes included student achievement with computer-assisted instruction (CAI) and student attitude toward CAI.

To examine these relationships, a researcher-developed CAI program on light and color theory was validated and administered to 144 students in an educational media course at the University of Northern Iowa. Participants in the study were first asked to complete the Grasha-Riechmann Student Learning Style Scales (GRSLSS) inventory along with a demographic survey. Next, each participant completed …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 9, Number 10, December 1993, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Local Area Network Implementation At The 4950th Test Wing: A Study Of The Relationship Between Individual Factors And The Effectiveness Of A Local Area Network, Doyle F. Cone, David J. Donahoo

Theses and Dissertations

This research investigated the individual factors which directly impacted the effectiveness of the 4950th Test Wing local area network (LAN). Areas of interest included the relationships between demographic and user attitude factors and LAN effectiveness. A literature review provided the basis for: 1) operationally defining effectiveness as a subjective measure of user satisfaction; 2) identifying specific factors which impact information system effectiveness; and 3) developing a research instrument to measure user attitudes and user satisfaction. A questionnaire was administered to 342 LAN users 173 were returned (a response rate of 51 percent). Sixteen factors (eight demographic factors and eight attitude …

Script-Based Qos Specifications For Multimedia Presentations, Richard Staehli, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Multimedia presentations can convey information not only by the sequence of events but by their timing. The correctness of such presentations thus depends on the timing of events as well as their sequence and content. This paper introduces a formal specification language for playback of real-time presentations. The main contribution of this language is a quality of service (QOS) specification that relaxes resolution and synchronization requirements for playback. Our definitions give a precise meaning to the correctness of a presentation. This specification language will form the basis for a QOS interface for reservation of operating system resources.

Partitioning Structural Vhdl Circuits For Parallel Execution On Hypercubes, Kevin L. Kapp

Theses and Dissertations

Distributing simulations among multiple processors is one approach to reducing VHDL simulation time for large VLSI circuit designs. However, parallel simulation introduces the problem of how to partition the logic gates and system behaviors among the available processors in order to obtain maximum speedup. This research investigates deliberate partitioning algorithms that account for the complex inter-dependency structure of the circuit behaviors. Once an initial partition has been obtained, a border annealing algorithm is used to iteratively improve the partition. In addition, methods of measuring the cost of a partition and relating it to the resulting simulation performance are investigated. Structural …

Interactive Control Of A Parallel Simulation From A Remote Graphics Workstation, Douglas C. Looney

Theses and Dissertations

Modern military commanders are faced with an overwhelming amount of intelligence data concerning the disposition of engaging forces, The sheer volume of data produced for a single planning scenario is an obstacle to the user as well as the computer. Today’s commander requires a real-time, three- dimensional representation of the battlefield in order to assimilate the data for the management of a conflict. Parallel computation is required to complete the processing of this information in a timely manner. A network protocol is required to link the interface with the parallel simulation. The of this study is to improve user interaction …