Digital Commons Network^™

Analysis And Design Of Standard Telerobotic Control Software, Matthew L. June

Theses and Dissertations

The Robotics and Automation Center for Excellence (RACE) has defined an open telerobotics control architecture. This architecture, called the Unified Telerobotic Architecture Project (UTAP), is a proposed standard for all Air Force telerobotic systems. Implementation of UTAP will reduce the cost of robotic applications by increasing software modularity, portability, and reusability. This thesis continued the effort to prove the feasibility of UTAP. In December, 1995, 1st Lt Anchor implemented a portion of the UTAP specification on a PUMA robot. The UTAP-compliant controller exhibited some degradation in the system performance. However, the performance degradation was not fully measured. This thesis extended …

Refined Genetic Algorithms For Polypeptide Structure Prediction, Charles E. Kaiser Jr.

Theses and Dissertations

Accurate and reliable prediction of macromolecular structures has eluded researchers for nearly 40 years. Prediction via energy minimization assumes the native conformation has the globally minimal energy potential. An exhaustive search is impossible since for molecules of normal size, the size of the search space exceeds the size of the universe. Domain knowledge sources, such as the Brookhaven PDB can be mined for constraints to limit the search space. Genetic algorithms (GAs) are stochastic, population based, search algorithms of polynomial (P) time complexity that can produce semi-optimal solutions for problems of nondeterministic polynomial (NP) time complexity such as PSP. Three …

Elicitation Of Formal Software Specifications From An Object-Oriented Domain Model, Timothy Karagias

Theses and Dissertations

The ability to provide automated support for the generation of formal software specifications would lead to decreased software development time. By eliciting the needed information from a software developer and harvesting the proper parts of a domain model, a software specifications document could be created. This research establishes the feasibility of producing customized software specifications based on an object-oriented domain model. The research was conducted in three phases. The first phase was to define the requirements for the Elicitor Harvester. Those requirements were balanced between the capabilities of the existing Knowledge Based Software Engineering (KBSE) software used at AFIT and …

Molecular Articulation In Response To Interactive Atomic Forces In Docker, Todd R. Kellett

Theses and Dissertations

Molecular docking aids in the design of materials supporting the current and future needs of the warfighter by simulating the real-world results of combining molecules. Specifically, it supports research and development in novel non-linear optical materials for laser-hardening and other advanced optical applications. Potential uses for these materials range from personnel and optical system laser protection to holographic information displays. DOCKER, our baseline docking system, minimizes the computational overhead of the simulation by modeling the molecules as rigid objects. This simplification can cause DOCKER's solutions to disagree with the real-world results, because molecules flex as they react to one another …

An Approach To Evaluate Software Effectiveness, Timothy J. Schalick

Theses and Dissertations

The Air Force Operational Test and Evaluation Center (AFOTEC) is tasked with the evaluation of operational effectiveness of new systems for the Air Force. Currently, the software analysis team within AFOTEC has no methodology to directly address the effectiveness of the software portion of these new systems. This research develops a working definition for software effectiveness, then outlines an approach to evaluate software effectiveness-- the Software Effectiveness Traceability Approach (SETA). Effectiveness is defined as the degree to which the software requirements are satisfied and is therefore application-independent. With SETA, requirements satisfaction is measured by the "degree of traceability" throughout the …

Survivability Analysis Of The Iridium Low Earth Orbit Satellite Network, Douglas K. Stenger

Theses and Dissertations

This thesis evaluates the survivability of the proposed Iridium Low Earth Orbit (LEO) Satellite Network. In addition to the complete Iridium constellation, three degraded Iridium constellations are analyzed. This analysis occurs via the use of simulation models, which are developed to use three dynamic routing algorithms over three loading levels. The Iridium network models use a common set of operating assumptions and system environments. The constellation survivability was determined by comparing packet rejection rates, hop' counts, and average end to end delay performance between the various network scenarios. It was concluded that, based on the established scenarios, the proposed Iridium …

Collaborative Workspaces Within Distributed Virtual Environments, William D. Wells

Theses and Dissertations

In warfare, be it a training simulation or actual combat, a commander's time is one of the most valuable and fleeting resources of a military unit. Thus, it is natural for a unit to have a plethora of personnel to analyze and filter information to the decision-maker. This dynamic exchange of ideas between analyst and commander is currently not available within the distributed interactive simulation (DIS) community. This lack of exchange limits the usefulness of the DIS experience to the commander and his troops. This thesis addresses the commander's isolation problem through the integration of a collaborative workspace within AFIT's …

An Incremental Language Conversion Method To Convert C++ Into Ada95, Ding-Yuan Sheu

Theses and Dissertations

This thesis develops a methodology to incrementally convert a legacy object oriented C++ application into Ada95. Using the experience of converting a graphic application, called Remote Debriefing Tool (RDT), in the Graphics Lab of the Air Force Institute of Technology (AFIT), this effort defined a process to convert a C++ application into Ada95. The methodology consists of five phases: (1) reorganizing the software application, (2) breaking mutual dependencies, (3) creating package specifications to interface the existing C++ classes, (4) converting C++ code into Ada programs, and (5) embellishing. This methodology used the GNAT's C++ low level interface capabilities to support …

Analysis And Simulation Of A New Code Tracking Loop For Gps Multipath Mitigation, Mark C. Laxton

Theses and Dissertations

This thesis proposes a new direct sequence spread spectrum (DS/SS) code phase tracking loop which mitigates the effects of multipath interference on code phase tracking error; such errors can translate to significant range measurement errors in DS/SS ranging systems such as Global Positioning System (GPS). The new code tracking loop, called the modified RAKE delay lock loop (MRDLL), uses maximum likelihood (ML) signal parameter estimation to determine the amplitude, carrier phase, and relative propagation delay of both a direct path and a reflected signal; a multiple correlator code phase tracking loop then exploits these ML signal estimates to remove the …

A Strategy For Distributed Relational Database Design, Ismail Omar Hababeh

Masters Theses

This thesis presents a strategy for the fragmentation and allocation of data in a distributed relational database. The strategy introduces a way to fragment and allocate data to accomplish the benefits of allocating each fragment independently for each site. Some fragments may be allocated to multiple sites in order to achieve some constraints such as availability, consistency, and integrity. The strategy is appropriate for different types of computers at various sites connected to a network, with different costs of retrieval, update, and communication.

To increase the system 1/0 performance, sites having similar communication costs are grouped into clusters to which …

A Cscw Framework For Networked Multimodal Synthetic Environments, Chandrajit L. Bajaj, Fausto Berardini, Steven Cutchin, Raimund Merket

Department of Computer Science Technical Reports

No abstract provided.

Entropy Computations Via Analytic Depoissonization, Philippe Jacquet, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Misplaced Trust: Kerberos 4 Session Keys, Bryn Dole, Steve Lodin, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

On The Approximate Pattern Occurrences In A Text, Mireille Régnier, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

The Purdue Pse Kernel: Towards A Kernel For Building Pses, Sanjiva Weerawarana, Elias N. Houstis, John R. Rice, Ann C. Catlin, Margaret G. Gaitatzes, Shahani Markus, Tzveten T. Drashansky

Department of Computer Science Technical Reports

No abstract provided.

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

Department of Computer Science Technical Reports

No abstract provided.

Knowledge Discovery In Computational Science: A Case Study In Algorithm Selection, N. Ramakrishnan, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Efficient Parallel Algorithms On Reconfigurable Mesh Architectures, His-Chieh Lee, Fikret Ercal

Computer Science Technical Reports

This dissertation describes a number of novel parallel algorithms for solving maze-routing problems and string matching problems on a proposed reconfigurable mesh architecture.

Section I reviews the field of reconfigurable parallel computing. This includes an introduction to a number of reconfigurable architectures proposed in the literature and a list of references to the current literature on algorithms in the field of reconfigurable computing.

Section II presents a number of time-efficient algorithms to solve the mazerouting problem. Maze-routing algorithms are used in VLSI routing and robot path planning. In that section, definitions for absolute shortest path (ASP), shortest duplex-path (SDP), shortest …

Parallel Fast Multipole Algorithms For N-Body Simulations, Jui-Lin Lu, Daniel Okunbor

Computer Science Technical Reports

The computer simulation of N-Body problems has a wide range of applications. It is known that simulations can take years to complete. This can be greatly improved by using efficient algorithms in force calculations and in applying the computing power of parallel computers to the problem. A tremendous amount of work has been devoted to parallelization of the fast multipole algorithm (FMA) which is one of the fastest algorithms in force calculations. However, most parallel implementations target a specific machine. We developed an efficient communication scheme for parallel FMA in a message passing environment and implemented it by using Message …

A Common Architecture For Simulation Viewing Over Multiple Protocol Environments, Glenn G. Jacquot

Theses and Dissertations

This study discusses an architecture used for displaying data results in a graphical format. This data is obtained via internet connection or from a direct connection to a battlefield simulator known as BattleSim. This architecture utilizes several graphics packages for displaying the output along with two different approaches to receiving commands from the user. Furthermore, the design was built to easily incorporate other graphics packages and communication protocols in order to increase its portability.

Implementation Of An Ada95 Crosscompiler For The Real-Time Executive For Military Systems (Rtems), Kendall M. Lemley Jr.

Theses and Dissertations

This thesis represents a continuation of the assessment of the Unified Telerobotics Architecture Project (UTAP), a proposed Air Force standard. This architecture was developed by the NASA Jet Propulsion Laboratory and the National Institute of Standards under contract to the Air Force Materiel Command Robotics and Automation Center of Excellence at Kelly AFB, Texas. Due to operating system constraints, the only UTAP implementation to date has required a separate software interface layer, adding complexity and overhead to the overall system, while reducing portability. This thesis proposes a long term effort to design and implement UTAP-compliant application software devoid of this …

A Specific Network Link And Path Likelihood Prediction Tool, Gary K. Moy

Theses and Dissertations

Communications have always been a crucial part of any military operation. As the pace of warfare and the technological complexity of weaponry have increased, so has the need for rapid information to assess battlefield conditions. Message passing across a network of communication nodes allowed commanders to communicate with their forces. It is clear that an accurate prediction of communication usage through a network will provide commanders with useful intelligence of friendly and unfriendly activities. Providing a specific network link and path likelihood prediction tool gives strategic military commanders additional intelligence information and enables them to manage their limited resources more …

Weighted Mahalanobis Distance For Hyper-Ellipsoidal Clustering, Khaled S. Younis

Theses and Dissertations

Cluster analysis is widely used in many applications, ranging from image and speech coding to pattern recognition. A new method that uses the weighted Mahalanobis distance (WMD) via the covariance matrix of the individual clusters as the basis for grouping is presented in this thesis. In this algorithm, the Mahalanobis distance is used as a measure of similarity between the samples in each cluster. This thesis discusses some difficulties associated with using the Mahalanobis distance in clustering. The proposed method provides solutions to these problems. The new algorithm is an approximation to the well-known expectation maximization (EM) procedure used to …

A Specialization Toolkit To Increase The Diversity Of Operating Systems, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

Virus and worm attacks that exploit system implementation details can be countered with a diversified set of implementations. Furthermore, immune systems show that attacks from previously unknown organisms require effective dynamic response. In the Synthetix project, we have been developing a specialization toolkit to improve the performance of operating system kernels. The toolkit helps programmers generate and manage diverse specialized implementations of software modules. The Tempo-C specializer tool generates different versions for both compile-time and run-time specialization. We are now adapting the toolkit to improve operating system survivability against implementations attacks.

Evaluation Of Segmentation For Bone Structures In 3d Rendering Of Ultrasound Residual Limb Images, Min C. Baker

Theses and Dissertations

Prosthetists today widely practice manual socket fitting, which produces subjective, inconsistent results. To address this problem, the Computerized Anthropometry Research and Design (CARD) Laboratory is developing a computer-aided socket design system that acquires ultrasound datasets of an amputee's residual limb, creates a 3D model, and helps identify load- bearing and pressure-relief areas. This research project focuses on providing 3D visualization of a residual limb to support the CARD Laboratory's efforts. Creating the 3D model of the skin and two bone contours requires two major steps: segmentation to identify the objects of interest and a surface tracking algorithm to generate the …

Master Of Science In Computing Technology In Education 1996, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

The Dark Side Of Risk (What Your Mother Never Told You About Time Warp), David M. Nicol, Xiaowen Liu

Computer Science Technical Reports

This paper is a reminder of the danger of allowing ``risk'' when synchronizing a parallel discrete-event simulation: a simulation code that runs correctly on a serial machine may, when run in parallel, fail catastrophically. This can happen when Time Warp presents an ``inconsistent'' message to an LP, a message that makes absolutely no sense given the LP's state. Failure may result if the simulation modeler did not anticipate the possibility of this inconsistency. While the problem is not new, there has been little discussion of how to deal with it; furthermore the problem may not be evident to new users …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 9, November 1996, 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.

A Critique Of The Telecommunications Description Language (Ted), Brian J. Premore, David M. Nicol, Xiaowen Liu

Computer Science Technical Reports

TeD is an object-oriented description language designed to facilitate the modeling of large scale telecommunication networks, with simulation on parallel and distributed platforms. TeD models are mapped to the Georgia Tech Time Warp engine (GTW) for execution. In this paper we outline the features of TeD, pointing out its strengths and identifying characteristics that gave us trouble as we used TeD to model detailed networks. Our issues are motivated specifically by a model of TCP and a model of multicast resource allocation. Our intention is to illustrate by example what TeD can do, and characteristics that a potential TeD user …

Quality Of Service Test By Codec Performance, Shunge Li, Bharat Bhargava, Dawei Wang

Department of Computer Science Technical Reports

No abstract provided.