Digital Commons Network^™

The Design And Evaluation Of Distributed Graph-Theoretic Heuristics For Computing Pairwise Interactions Of Moving Entities, Darren R. Law

Link Foundation Modeling, Simulation and Training Fellowship Reports

In recent years the focus of training simulations, particularly those in the defense domain, has been on increasing the number of simulated entities. This focus, coupled with the requirement for geographically distributed training sites, has led to increased interest in distributed simulation of the battlefield environment. The large efforts involved in the development of the DIS (Distributed Interactive Simulation) protocol and the HLA (High Level Architecture) have attempted to address these DoD (Department of Defense) requirements in several ways. The cost of con1puting the interactions between pairs of simulated entities frequently dominates system execution time. The difficulty of evaluating these …

Optimizing Amplifier Placements In A Multiwavelength Optical Lan/Man: The Equally Powered-Wavelengths Case, Byrav Ramamurthy, Jason Iness, Biswanath Mukherjee

School of Computing: Faculty Publications

Wavelength division multiplexing (WDM) provides the ability to utilize the enormous bandwidth offered by optical networks, using today’s electronics. WDM-based optical networks employing passive-star couplers have been proposed for deployment in local and metropolitan areas. Optical amplification is often required in such networks to compensate for the signal attenuation along the fiber links and the splitting and coupling losses in the network. However, an optical amplifier has constraints on the maximum gain and the maximum output power it can supply; thus optical amplifier placement becomes a challenging problem. A simplifying assumption for analytical tractability requires that all wavelengths, present at …

A Feedback-Driven Proportion Allocator For Real-Rate Scheduling, David Steere, Ashvin Goel, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatically both proportion and period. Applications with known requirements, such as isochronous software devices, can bypass the adaptive scheduler by specifying their desired proportion and/or period. As a result, our scheme provides reservations to applications that need them, and the benefits of proportion and period to those that do not. Adaptive …

The Effects Of Three Media Presentation Systems On Maintenance Task Performance, John W. Chastain

Theses and Dissertations

Wearable computers and Portable Maintenance Aids (PMAs) may soon be the normal way of doing aircraft maintenance in the Air Force. Currently, the Air Force uses the paper form of Technical Orders (TO's) while doing aircraft maintenance. The purpose of this thesis was to compare the effects of three different media presentations of the information used during aircraft maintenance. The three different presentations compared are the current paper form, a Head Mounted Display (HMD), and an auditory mode. An experiment was conducted to determine if there was a significant difference between the systems (in terms of task completion times and …

Radial Complexity Estimation For Improved Generalization In Artificial Neural Networks, Lemuel R. Myers Jr.

Theses and Dissertations

When training an artificial neural network (ANN) for classification using backpropagation of error, the weights are usually updated by minimizing the sum-squared error on the training set. As training ensues, overtraining may be observed as the network begins to memorize the training data. This occurs because, as the magnitude of the weight vector, W, grows, the decision boundaries become overly complex in much the same way as a too-high order polynomial approximation can overfit a data set in a regression problem. Since w grows during standard backpropagation, it is important to initialize the weights with consideration to the importance of …

Average Profile Of The Lempel-Ziv Parsing Scheme For Markovian Source, Philippe Jacquet, Wojciech Szpankowski, Jing Tang

Department of Computer Science Technical Reports

No abstract provided.

Pythia-Ii: A Knowledge/Data Base For Testing And Recommending Scientific Software, Elias N. Houstis, Vassilios S. Verykios, Ann C. Caitlin, Naren Ramakrishnan, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Continuum: A Homotopy- Continuation Solver For Systems Of Algebraic Equations, Cassiano Durand, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

Parallel Solution Of Large Sparse Linear Systems By A Balance Scheme Preconditioner, Tz. Ostromsky, Ahmed Sameh, V. Sarin

Department of Computer Science Technical Reports

No abstract provided.

Spatial Contact Analysis Of Fixed- Axes Pairs Using Configuration Spaces, Iddo Drori, Leo Joskowicz, Elisha P. Sacks

Department of Computer Science Technical Reports

No abstract provided.

A Wavelet-Based Approach To Dynamic Environments, Glenn A. Martin

Link Foundation Modeling, Simulation and Training Fellowship Reports

This paper demonstrates a new approach for terrain representation: multiresolution surfaces based on wavelets and the process of multiresolution analysis. Because they are based on mathematical surfaces, multiresolution surfaces gain the benefits of surfaces (more level of detail control, increased number of possible resolutions, easier updates of a dynamic terrain) that lead to fewer correlation errors both in non-networked and networked simulations. Furthermore, the power of multiple resolutions (at little added cost) reduces network transmission costs and provides a framework for the use of dynamic terrain in shared virtual worlds.

Vision-Based Tracking With Dynamic Structure Light, Mark A. Livingston

Link Foundation Modeling, Simulation and Training Fellowship Reports

The term virtual reality (VR) has been used in the popular press to describe systems that completely replace the user's view with computer graphics, a view of a synthetic world. Such systems allow building designers to visualize the "completed" building and potential problems in the design before construction. A VR system might allow scientists to view environments as large as galaxies or as small as atoms as if they were human-sized. The primary benefit in these cases would be to interact in more natural ways with objects that, due to their sizes, are usually beyond our reach. In academic literature, …

Software Tools For Solid Freeform Fabrication, Robert Franceschini

Link Foundation Modeling, Simulation and Training Fellowship Reports

A structured design methodology played a key role in the VLSI (Very Large Scale Integration) revolution. In this methodology, the design is abstracted at different levels (viz. system, function, logic, circuit, and layout) taking into account concerns relevant to a particular level of abstraction. This allows development of CAD tools that can describe, synthesize, and simulate the design at high levels of abstraction independent of the details of the lower levels. In recent years, many researchers have observed that the lessons learned from the "VLSI experience" could be profitably applied to new classes of manufacturing processes called SFF (Solid Freeform …

Wavelength Conversion In Wdm Networking, Byrav Ramamurthy, Biswanath Mukherjee

School of Computing: Faculty Publications

Wavelength conversion has been proposed for use in wavelength-division multiplexed networks to improve efficiency. This study highlights systems challenges and performance issues which need to be addressed in order to incorporate wavelength conversion effectively. A review/survey of the enabling technologies, design methods, and analytical models used in wavelength-convertible networks is provided.

Automatic Target Cueing Of Hyperspectral Image Data, Terry A. Wilson

Theses and Dissertations

Modern imaging sensors produce vast amounts data, overwhelming human analysts. One such sensor is the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) hyperspectral sensor. The AVIRIS sensor simultaneously collects data in 224 spectral bands that range from 0.4µm to 2.5µm in approximately 10nm increments, producing 224 images, each representing a single spectral band. Autonomous systems are required that can fuse "important" spectral bands and then classify regions of interest if all of this data is to be exploited. This dissertation presents a comprehensive solution that consists of a new physiologically motivated fusion algorithm and a novel Bayes optimal self-architecting classifier …

A Decision Theoretic Approach For Interface Agent Development, Scott M. Brown

Theses and Dissertations

The complexity of current software applications is overwhelming users. The need exists for intelligent interface agents to address the problem of increasing taskload that is overwhelming the human user. Interface agents could help alleviate user taskload by extracting and analyzing relevant information, and providing information abstractions of that information, and providing timely, beneficial assistance to users. These agents could communicate with the user through the existing user interface and also adapt to user needs and behaviors. Central to providing assistance to a user is the issue of correctly determining the user's intent. This dissertation presents an effective, efficient, and extensible …

Minimum Cross-Entropy Approximation For Modeling Of Highly Intertwining Data Sets At Subclass Levels, Qiuming Zhu

Computer Science Faculty Publications

We study the problem of how to accurately model the data sets that contain a number of highly intertwining sets in terms of their spatial distributions. Applying the Minimum Cross-Entropy minimization technique, the data sets are placed into a minimum number of subclass clusters according to their high intraclass and low interclass similarities. The method leads to a derivation of the probability density functions for the data sets at the subclass levels. These functions then, in combination, serve as an approximation to the underlying functions that describe the statistical features of each data set.

A Resource Allocation Mechanism Based On Cost Function Synthesis In Complex Systems, Carlos C. Amaro

Dissertations

While the management of resources in computer systems can greatly impact the usefulness and integrity of the system, finding an optimal solution to the management problem is unfortunately NP hard. Adding to the complexity, today's 'modern' systems - such as in multimedia, medical, and military systems - may be, and often are, comprised of interacting real and non-real-time components. In addition, these systems can be driven by a host of non-functional objectives – often differing not only in nature, importance, and form, but also in dimensional units and range, and themselves interacting in complex ways. We refer to systems exhibiting …

A Folder Organization Model For Information Systems : Exploring Its Architectural Expressive Power And Predicate-Based Filing, Simon Doong

Dissertations

This dissertation presents an Internal Folder Organization (I-ORG) which supplements the architectural deficiencies of the existing model - the User Folder Organization (U-ORG), to electronically model a person's filing system in the modern office environment. An I-ORG folder organization gives a logical representation of how documents of the same or different kinds are related and grouped into folders based on predefined premises. Our model is represented by a Rooted Direct Acyclic Graph (RDAG). Each node in the graph represents a folder; and folders are related by "subfolder relationship" (for capturing the "and" relation) and "virtual-folder relationship" (for capturing the "or" …

A Graph Based Process Model Measurement Framework Using Scheduling Theory, Gary Guang-Li Mou

Dissertations

Software development processes, as a means of ensuring software quality and productivity, have been widely accepted within the software development community; software process modeling, on the other hand, continues to be a subject of interest in the research community. Even with organizations that have achieved higher SEI maturity levels, processes are by and large described in documents and reinforced as guidelines or laws governing software development activities. The lack of industry-wide adaptation of software process modeling as part of development activities can be attributed to two major reasons: lack of forecast power in the (software) process modeling and lack of …

Requirement Elicitation And Knowledge Management Utilizing Relational Database, Client Server And Internet Technologies, Umang J. Dave

Theses

The first step in any project is a statement of requirements. Requirements specification is an inevitable part of any successful project. However, the "rush" to convert concepts to products often proves as a big hindrance in the development process of any requirements set. This, in turn, hampers the ability to produce the concept and manage knowledge as originally envisioned.

The goal of the thesis is to foster understanding among the different communities affected by the development of the given system. The thesis is based on the principle that the requirements elicitation process for complex system is fundamentally a conversation among …

Process Modeling Using Proslcse On Web-Enabled Platform, Orcan Ali Enunlu

Theses

Process modeling is a relatively complex task that needs to be addressed from a different point of view. The classical approach would be to design the model, to send it for evaluation, then to return feedback to the developing team, and to reevaluate the model with the feedback received from the parties involved.

However, it is our understanding that the steps taken during the process modeling could benefit from the advantages that the Internet offers. To demonstrate the usefulness of Internet in process modeling, I have taken an existing tool, ProSLCSE, and implemented it with Java so that it can …

Applications Of Parallel I/O, Ron Oldfield, David Kotz

Computer Science Technical Reports

Scientific applications are increasingly being implemented on massively parallel supercomputers. Many of these applications have intense I/O demands, as well as massive computational requirements. This paper is essentially an annotated bibliography of papers and other sources of information about scientific applications using parallel I/O. It will be updated periodically.

Collaborative Decision Support Systems For Facility Management, Arthur J. Chapman, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based collaborative decision support is a methodology of utilizing domain specific intelligent systems, interacting in a common environment, to partner with one or more human decision makers to reach a consensus solution to a complex problem. An example is the recently developed Collaborative Infrastructure Assessment Tool (CIAT) that provides a collaborative planning facility management tool in support of military pier and port management. This methodology is applicable to many similar dynamic facility management problems where the complexity of issues and the number of decision makers result in the need for domain specific agents, a common view of the data, and …

The Future Of Computing: Cyberspace, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper traces trends in the technological advances of computer and communication systems and examines the promises of the Information Society: global information sharing; and, intelligent decision-support. The technological developments that will lead to the realization of Cyberspace, an information rich environment in which virtual reality capabilities couple directly to the human senses, is explored in terms of five essential components: information processing requirements; communication networks; computing devices (i.e., platforms); hardware and software user-interfaces; and, the meaningful representation of information.

Attention is drawn to the critical role played by information representation in a Cyberspace environment. The author argues …

The Round Table Model: A Web-Oriented, Agent-Based Approach To Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Not unlike King Arthur relying on the infamous Round Table as the setting for consultation with his most trusted experts, agent-based, decision-support systems provide human decision makers with a means of solving complex problems through collaboration with collections of both human and computer-based expert agents. The Round Table Framework provides a formalized architecture together with a set of development and execution tools which can be utilized to design, develop, and execute agent-based, decision-support applications. Based on a three-tier architecture, Round Table incorporates forefront technologies including distributed-object servers, inference engines, and web-based presentation to provide a framework for collaborative, agent-based decision …

Improving Performance On Incremental Compilation Of Java Bytecodes, Tarique Kazi

Honors Capstone Projects and Theses

No abstract provided.

Synthetic Files: Enabling Low-Latency File I/O For Qos-Adaptive Applications, Dylan Mcnamee, Dan Revel, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Files are a tried and true operating system abstraction. They present a simple byte-stream model of I/O that has proven intuitive for application programmers and efficient for operating system builders. However, current file systems do not provide good support for adaptive continuous media (CM) applications - an increasingly important class of applications that exhibit complex access patterns and are particularly sensitive to variations in I/O performance. To address these problems we propose synthetic files. Synthetic files are specialized views of underlying regular files, and convert complex file access patterns into simple sequential synthetic file access patterns. Synthetic file construction can …

On Agent Communication In Large Groups, Gary R. Greenfield

Department of Math & Statistics Technical Report Series

The problem is fundamental and natural, yet deep - to simulate the simplest possible form of communication that can occur within a large multi-agent system. It would be prohibitive to try and survey all of the research on "communication" in general so we must restrict our focus. We will devote our efforts to synthetic communication occurring within large groups. In particular, we would like to discover a model for communication that will serve as an abstract model, a prototype, for simulating communication within large groups of biological organisms.

Computer-Aided Mechanical Design Using Configuration Spaces, Leo Joskowicz, Elisha Sacks

Department of Computer Science Technical Reports

No abstract provided.