Digital Commons Network^™

Modeling And Comparison Of Wormhole Routed Mesh And Torus Networks, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

2D-mesh and torus networks have often been proposed as the interconnection pattern for parallel computers. In addition, wormhole routing has increasingly been advocated as a method of reducing latency. Most analysis of wormhole routed networks, however, has focused on the torus and the broader class of k-ary n-cubes to which it belongs. This paper presents a performance model for the wormhole routed mesh, and it compares the performance of the mesh and torus based on theoretical and empirical analyses.

Solving Pdes Using An Agent Based Architecture, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 7, September 1997, 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.

Defining And Refining Frameless Rendering, Ellen J. Scher Zagier

Link Foundation Modeling, Simulation and Training Fellowship Reports

Frame1ess Rendering (FR) is a rendering paradigm which performs stochastic temporal filtering by updating pixels in a random order, based on most recent available input data, and displaying them to the screen immediately (3]. It has inherent in its design, visual artifacts that come across as "spatial scatter''. Due to the asynchronicity of pixel updates, a noisy or "scattered" image is perceived if the update rate is not fast enough. We describe the fac1ors that influence the perceptual quality when Frarneless Rendering is implemented such as object and viewpoint velocities, pattern and object size, and pattern and object separation. The …

From Contemporary Workflow Process Automation To Adaptive And Dynamic Work Activity Coordination And Collaboration, Amit P. Sheth

Kno.e.sis Publications

The article outlines a research agenda for researchers in the area of workflow. We believe that today's workflow systems should evolve to what is termed as work coordination and collaboration systems (WCCSs). A WCCS will: (a) adapt to various changes in the organization (including its interactions with external organizations) and the organizational processes by being able to change the process definitions as well as change the processes and component activities while they are being enacted or executed; and (b) support a unified framework for managing coordination, collaboration, and information based decision making activities that naturally occur as part of organizational …

Information Retrieval On The World Wide Web, Venkat N. Gudivada, Vijay V. Raghavan, William I. Grosky, Rajesh Kasanagottu

Computer Science Faculty Research & Creative Works

Effective search and retrieval are enabling technologies for realizing the full potential of the Web. The authors examine relevant issues, including methods for representing document content. They also compare available search tools and suggest methods for improving retrieval effectiveness.

Complexity And Decomposability Of Relations, Martin Zwick

Complex Systems Faculty Publications and Presentations

A discrete multivariate relation, defined set-theoretically, is a subset of a cartesian product of sets which specify the possible values of a number of variables. Where three or more variables are involved, the highest order relation, namely the relation between all the variables, may or may not be decomposable without loss into sets of lower order relations which involve subsets of the variables. In a completely parallel manner, the highest order relation defined information-theoretically, namely the joint probability distribution involving all the variables, may or may not be decomposed without loss into lower-order distributions involving subsets of the variables. Decomposability …

Calibration And Validation Of The Checkpoint Model To The Air Force Electronic Systems Center Software Database, Thomas C. Shrum

Theses and Dissertations

This research effort focused on the calibration and validation of CHECKPOINT Version 2.3.1, a computerized software cost estimating tool, to the USAF Electronic Systems Center (ESC) software database. This thesis is a direct follow-on to a 1996 CHECKPOINT study at the Air Force Institute of Technology, which successfully calibrated and validated CHECKPOINT to the SMC software database. While this research generally parallels the methodology in the aforementioned study, it offers advancements in the CHECKPOINT calibration and validation procedure, and it refines the data stratification process and the statistical analyses employed. After stratifying the ESC software database into ten usable data …

Extracting Functionally Equivalent Object-Oriented Designs From Legacy Imperative Code, Ricky E. Sward

Theses and Dissertations

This research defines a methodology for automatically extracting functionally equivalent object-oriented designs from legacy imperative programs. The Parameter-Based Object Identification (PBOI) methodology is based on fundamental ideas that relate programs written in imperative languages such as C or COBOL to objects and classes written in object-oriented languages such as Ada 95 or C ++. Transformations have been developed that formalize the PBOI methodology and a formal proof is provided showing the extracted object-oriented design is functionally equivalent to the legacy imperative system. To focus the task of re-engineering, generic models of imperative programming languages and object-oriented programming languages have been …

Distributed Collaborative Learning Environments, Mark C. Kilby

Link Foundation Modeling, Simulation and Training Fellowship Reports

The evolution of technologies for the World Wide Web (WWW), computer-supported cooperative work (CSCW) and distributed simulation provides new opportunities for education delivery as well as unique perspectives for training. Simulation follows a learn-by-doing philosophy . The WWW and CSCW provides a collaborative learning perspective by encouraging collective knowledge building. By merging these two approaches, Distributed Collaborative Learning Environments (DCLEs) can be developed to provide new approaches to training in the military, industry, and academia. Traditional approaches toward educational rely on an information transfer model. Instructors deliver the material to the students and students are tested on how well they …

Post-Rendering 3d Image Warping, William R. Mark

Link Foundation Modeling, Simulation and Training Fellowship Reports

A pair of rendered images and their Z-buffers contain almost all of the information necessary to re-render from nearby viewpoints. For the small changes in viewpoint that occur in a fraction of a second, this information is sufficient for high quality re-rendering with cost independent of scene complexity. Re-rendering from previously computed views allows an order-of-magnitude increase in apparent frame rate over that provided by conventional rendering alone. It can also compensate for system latency in local or remote display. We use McMillan and Bishop's image warping algorithm to re-render, allowing us to compensate for viewpoint translation as well as …

Search For Sleptons In E+E- Collisions At Centre-Of-Mass Energies Of 161 Gev And 172 Gev, R. Barate, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

The data recorded by the ALEPH experiment at LEP at centre–of–mass energies of 161 GeV and 172 GeV were analysed to search for sleptons, the supersymmetric partners of leptons. No evidence for the production of these particles was found. The number of candidates observed is consistent with the background expected from four–fermion processes and γγ–interactions. Improved mass limits at 95% C.L. are reported.

A Measurement Of The Qcd Colour Factors And A Limit On The Light Gluino, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios CA/CF and TF /CF and the strong coupling constant αs = CFαs(MZ)/(2π) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD, {fx4-1} Fixing CA/CF and TF/CF to the QCD values permits a determination of αs(MZ) and ηf, the number of active flavours. With this measurement the existence of a gluino with mass below 6.3 GeV/c2 is excluded at …

Human-Computer Partnership In Decision-Support Systems: Some Design Guidelines, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

The design of useful human-computer collaborative decision-support systems requires some understanding of the behavioral and organizational characteristics of human problem solving practices. This paper identifies the principal areas in which computer-based decision making assistance is particularly attractive and critically examines several human problem solving traits that may not be appropriate for direct emulation in the computer-assisted environment. In particular, the author examines the manner in which emotions and hierarchical leadership structures could unnecessarily inhibit the realization of the full potential of a human-computer partnership. Finally, a number of guiding principles are proposed for the design of computer-based decision-support systems.

Cheetahs Are Fast, But Nearly Irrelevant, Calton Pu, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

A brief paper submitted to the NSF Workshop on New Challenges and Directions for Systems Research, held in St. Louis, Mo., July 31-August 1, 1997. Outlines the case for more cooperation among software system architects, and a less reductionistic approach to software development.

Time-Efficient Maze Routing Algorithms On Reconfigurable Mesh Architectures, Fikret Ercal, H. C. Lee

Computer Science Faculty Research & Creative Works

The routing problem is one of the most widely studied problems in VLSI design. Maze-routing algorithms are used in VLSI routing and robot path planning. Efficiency of the parallel maze routing algorithms which were mostly based on C. Y. Lee's algorithm8is poor. In this paper, we propose time-efficient algorithms to solve the maze-routing problem on a reconfigurable mesh architecture. The constant-time algorithms presented include: (i) testing the existence of specific types of paths between two terminals, and (ii) finding an absolute shortest path (ASP) and a shortest duplex-path (SDP). In addition, a fast algorithm to find the single shortest path …

Performing Out-Of-Core Ffts On Parallel Disk Systems, Thomas H. Cormen, David M. Nicol

Computer Science Technical Reports

The Fast Fourier Transform (FFT) plays a key role in many areas of computational science and engineering. Although most one-dimensional FFT problems can be solved entirely in main memory, some important classes of applications require out-of-core techniques. For these, use of parallel I/O systems can improve performance considerably. This paper shows how to perform one-dimensional FFTs using a parallel disk system with independent disk accesses. We present both analytical and experimental results for performing out-of-core FFTs in two ways: using traditional virtual memory with demand paging, and using a provably asymptotically optimal algorithm for the Parallel Disk Model (PDM) of …

Generating, Visualizing And Evaluating High Quality Clusters For Information Organization, Javed Aslam, Katya Pelekhov, Daniela Rus

Computer Science Technical Reports

We present and analyze the star clustering algorithm. We discuss an implementation of this algorithm that supports browsing and document retrieval through information organization. We define three parameters for evaluating a clustering algorithm to measure the topic separation and topic aggregation achieved by the algorithm. In the absence of benchmarks, we present a method for randomly generating clustering data. Data from our user study shows evidence that the star algorithm is effective for organizing information.

Learning Recursive Functions From Approximations, John Case, Susanne Kaufmann, Martin Kummer, Efim Kinber

School of Computer Science & Engineering Faculty Publications

This article investigates algorithmic learning, in the limit, of correct programs for recursive functionsffrom both input/output examples offand several interesting varieties ofapproximateadditional (algorithmic) information aboutf. Specifically considered, as such approximate additional information aboutf, are Rose's frequency computations forfand several natural generalizations from the literature, each generalization involving programs for restricted trees of recursive functions which havefas a branch. Considered as the types of trees are those with bounded variation, bounded width, and bounded rank. For the case of learning final correct programs for recursive functions, EX-learning, …

Building Multi-Discipline, Multi-Format Digital Libraries Using Clusters And Buckets, Michael L. Nelson

Computer Science Theses & Dissertations

Our objective was to study the feasibility of extending the Dienst protocol to enable a multi-discipline, multi-format digital library. We implemented two new technologies: cluster functionality and publishing buckets. We have designed a possible implementation of clusters and buckets, and have prototyped some aspects of the resultant digital library.

Currently, digital libraries are segregated by the disciplines they serve ( computer science, aeronautics, etc.), and by the format of their holdings (reports, software, datasets, etc.). NCSTRL+ is a multi-discipline, multi-format digital library (DL) prototype created to explore the feasibility of the design and implementation issues involved with created a …

Parallel 3d Reconstruction Of Spherical Virus Particles From Digitized Images Of Entire Electron Micrographs Using Cartesian Coordinates And Fourier Analysis, Robert E. Lynch, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

Optical Components For Wdm Lightwave Networks, Michael S. Borella, Jason P. Jue, Dhritiman Banerjee, Byrav Ramamurthy, Biswanath Mukherjee

School of Computing: Faculty Publications

Recently, there has been growing interest in developing optical fiber networks to support the increasing bandwidth demands of multimedia applications, such as video conferencing and World Wide Web browsing. One technique for accessing the huge bandwidth available in an optical fiber is wavelength-division multiplexing (WDM). Under WDM, the optical fiber bandwidth is divided into a number of nonoverlapping wavelength bands, each of which may be accessed at peak electronic rates by an end user. By utilizing WDM in optical networks, we can achieve link capacities on the order of 50 THz. The success of WDM networks depends heavily on the …

Multiple Representation For Understanding Data Structures, Biffah Hancies, Venky Shankararaman, Jose Munoz

Research Collection School Of Computing and Information Systems

In this paper an approach to enhance the learning of abstract computing concepts by novice students is presented. This approach is based on effective use of multiple visual representations, and it was applied within the domain of linear data structures: array, stack, queue and linked list. A prototype computer-based instructional system called MRUDS (Multiple Representation for Understanding Data Structures) was developed and evaluated. It was found from the evaluation that the three presentation modules namely, analogy, representation and algorithm contributed to the students' learning process, each contributing to and reinforcing the effect of the others.

Influence And Consensus In Group Decision Making Environment, Fiona Fui-Hoon Nah, Byungcho Kim

Research Collection School Of Computing and Information Systems

In this research, the effect of expert support on influence and consensus in group decision making is investigated. The results indicate that ESS support diminishes the group members' influence on the group judgment as well as the influence exerted by the most influential group member. On the other hand, explanations support provided by ESS increases consensus in group decision making.

Using Expert Support And Its Explanation Facilities For Group Decision Making, Fiona Fui-Hoon Nah, Izak Benbasat

Research Collection School Of Computing and Information Systems

As information technology is increasingly used to support group work, it becomes desirable to identify the types of computer-based decision aids that are beneficial for supporting group decision making. In a review of the decision support literature, Benbasat, DeSanctis and Nault (1993) point out the lack of empirical research in examining the use of expert support for group decision making. In our review of the literature in this respect, we identified only one case study (Sviokla, 1989), which examined the processes involved in the pre- and post-use of an expert support system (ESS) called PlanPower by a group of financial …

Theoretical Foundation For Relationship Construct In Information Modeling – Relation Element Theory, Keng Siau

Research Collection School Of Computing and Information Systems

Information modeling is a critical process in software development. One of the key constructs in information modeling is the relationship construct. Though commonly used, the relationship construct is poorly defined and lacks a strong theoretical foundation. The objectives of this research are to define and classify the various relationships based on a theory in linguistic known as the relation element theory. This paper describes the theory, relates the theory to the relationship construct, and discusses the implication of the theory on the relationship construct.

The Self-Organizing Desk, Daniela Rus, Peter De Santis

Dartmouth Scholarship

The self-organizing desk is a system that enhances a physical desk-top with electronic information. It can remember, organize, update, and manipulate the information contained in the documents on a desk. The system consists of a simple robot eye that can survey the desk, a module for smart extraction of information from the images taken by the robot, a module for representing this information in multiple views, and a module that allows a user to interact with this information.

Fast Discrete Polynomial Transforms With Applications To Data Analysis For Distance Transitive Graphs, J. R. Driscoll, D. M. Healy, D. N. Rockmore

Dartmouth Scholarship

Let $\poly = \{P_0,\dots,P_{n-1}\}$ denote a set of polynomials with complex coefficients. Let $\pts = \{z_0,\dots,z_{n-1}\}\subset \cplx$ denote any set of {\it sample points}. For any $f = (f_0,\dots,f_{n-1}) \in \cplx^n$, the {\it discrete polynomial transform} of f (with respect to $\poly$ and $\pts$) is defined as the collection of sums, $\{\fhat(P_0),\dots,\fhat(P_{n-1})\}$, where $\fhat(P_j) = \langle f,P_j \rangle = \sum_{i=0}^{n-1} f_iP_j(z_i)w(i)$ for some associated weight function w. These sorts of transforms find important applications in areas such as medical imaging and signal processing.

In this paper, we present fast algorithms for computing discrete orthogonal polynomial transforms. For a system …

An Improved Analytical Model For Wormhole Routed Networks With Application To Butterfly Fat-Trees, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

A performance model for wormhole routed interconnection networks is presented and applied to the butterfly fat-tree network. Experimental results agree very closely over a wide range of load rate. Novel aspects of the model, leading to accurate and simple performance predictions, include (1) use of multiple-server queues, and (2) a general method of correcting queuing results based on Poisson arrivals to apply to wormhole routing. These ideas can also be applied to other networks.

Using The Quantum Computer To Break Elliptic Curve Cryptosystems, Jodie Eicher, Yaw Opoku

Department of Math & Statistics Technical Report Series

This article gives an introduction to Elliptic Curve Cryptography and Quantum Computing. It includes an analysis of Peter Shor’s algorithm for the quantum computer breakdown of Discrete Log Cryptosystems and an analog to Shor’s algorithm for Elliptic Curve Cryptosystems. An extended example is included which illustrates how this modified Shor’s algorithm will work.