Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences

PDF

1994

Institution
Keyword
Publication
Publication Type

Articles 31 - 60 of 376

Full-Text Articles in Physical Sciences and Mathematics

Easy-Sim: A Visual Simulation System Software Architecture With An Ada 9x Application Framework, Jordan R. Kayloe Dec 1994

Easy-Sim: A Visual Simulation System Software Architecture With An Ada 9x Application Framework, Jordan R. Kayloe

Theses and Dissertations

Software architectures increase productivity when used as the basis for developing applications in a problem domain. This thesis describes the creation of Easy-Sim, an object-oriented software architecture for visual simulation systems, and its corresponding implementation as an application framework in Ada 9X. The research built upon ObjectSim, an existing object-oriented simulation architecture implemented as a application framework. Both ObjectSim and Easy-Sim operate on Silicon Graphics platforms and use the IRIS Performer graphics programming library. Easy-Sim is implemented using version 1.83 of the GNAT compiler. The investigation for this thesis involved honing ObjectSim's design, implementing the improved result in both C++ …


Improving Intrusion Detection In Unix-Based Networks, David R. Landry Dec 1994

Improving Intrusion Detection In Unix-Based Networks, David R. Landry

Theses and Dissertations

Computer security has not kept pace with the rapid growth of networked systems. Through its connection to the Internet, the Department of Defense is vulnerable to computer-based attacks. Current intrusion detection systems are still unproven, too complicated, or too costly for most system security officers to implement. The attack methods used by system intruders are known and can be represented as groups of commands called attack signatures. This thesis investigates methods for detecting intruders by monitoring command usage. Testing was conducted in both controlled and uncontrolled circumstances. With controlled testing, it was shown that 7 of the 11 signatures could …


Development Of A Mammographic Image Processing Environment Using Matlab, John L. Kelley Dec 1994

Development Of A Mammographic Image Processing Environment Using Matlab, John L. Kelley

Theses and Dissertations

Breast cancer is a disease that accounts for a disturbingly large number of deaths in females each year. Its prevalence is a topic of concern to all of us since it can affect our families, friends, and coworkers. Although mammographic screening is the most effective method currently available for the early detection of breast cancer, it is far from being an infallible procedure. Mammographic reading is error prone, partly because of the complexity of the task and partly because of the variability in human performance. Computers offer high reproducibility, and when used as an adjunct by the radiologist, may improve …


Designing And Implementing An Ada Language Binding Specification For Odmg-93, Stephen R. Lindsay Dec 1994

Designing And Implementing An Ada Language Binding Specification For Odmg-93, Stephen R. Lindsay

Theses and Dissertations

Object-oriented database management systems (ODBMSs) represent the latest advancement in database technology, combining the reusability and maintainability of the object-oriented programming paradigm with the ability to efficiently store and retrieve a wide range of data types as well as code to manipulate stored data. Unfortunately, programmers developing software in the Ada programming language do not have the ability to interface to object databases without significant customized code development. One important reason for this has been the absence of a standard defining the constructs accessing ODBMS functionality. This thesis documents the creation of an Ada language binding to the ODMG-93 standard …


A General Object Model Transformation System, John P. Mullaney Dec 1994

A General Object Model Transformation System, John P. Mullaney

Theses and Dissertations

Cecil and Fullenkamp developed a program that transforms knowledge captured in an object-model in one environment into a different object-model in a different environment. This program worked well for the intended purpose, but if one of the object-models is replaced by a different object-model then this transformation program has to be re-engineered. As the object-modeling paradigm becomes more prevalent, many systems are experiencing this problem. The primary goal of this research was to determine what reusable knowledge could be extracted from these types of program and used to build a general object-model transformer that generalizes such transformation programs. Toward this …


A Numerical Model To Predict The Fate Of Jettisoned Aviation Fuel, Karl D. Pfeiffer Dec 1994

A Numerical Model To Predict The Fate Of Jettisoned Aviation Fuel, Karl D. Pfeiffer

Theses and Dissertations

While airborne, military and civilian aircraft must occasionally jettison unburned aviation fuel into the atmosphere. This research investigates the fate of a jettisoned fuel (e.g. JP-4, JP-8, etc.) from initial release to final ground fall by numerically modeling the physical phenomena governing the fate of this fuel: evaporation, advection, and dispersion. Using previous work in evaporation and free fall of fuel droplets as a foundation, this thesis presents an integrated evaporation advection and dispersion model designed to run under the resources of a typical personal computer. This integrated model is capable of using near real-time meteorological data (i.e. vertical profiles …


Modeling Workload Effectiveness And Efficiency Of Air Force Wing Command And Control, Michael D. Sarchet Dec 1994

Modeling Workload Effectiveness And Efficiency Of Air Force Wing Command And Control, Michael D. Sarchet

Theses and Dissertations

This research investigated the feasibility of applying software engineering technology to the Air Force wing command and control (C2) domain. As part of this research, domain analysis and object-oriented techniques were investigated and a specific approach was chosen to analyze the domain. Analysis of the domain resulted in an object-oriented domain model that captured the key objects, operations, and associations of wing C2. The domain model was used to design and implement a prototype software tool that enables wing decision makers to make assessments about automation's impact on wing C2 operations.


Multiple Model Adaptive Estimation And Head Motion Tracking In A Virtual Environment: An Engineering Approach, James E. Russell Dec 1994

Multiple Model Adaptive Estimation And Head Motion Tracking In A Virtual Environment: An Engineering Approach, James E. Russell

Theses and Dissertations

Software engineering tools and techniques were applied to design and implement an application that reduces lag typically present in virtual environment displays. The application was a Multiple Model Adaptive Estimator (MMAE), composed of three Kalman filters, that predicted head orientation one sample period into the future. The environment rendering software used these predictions to generate the environment display. Each of the filters in the MMAE was designed for a different assumed head motion type (benign, moderate, or heavy), which allowed the MMAE to adapt to changes in head movement characteristics. The use of Ada 9X as an implementation language for …


Minimizing The Impact Of Synchronization Overhead In Parallel Discrete Event Simulations, Andrew C. Walton Dec 1994

Minimizing The Impact Of Synchronization Overhead In Parallel Discrete Event Simulations, Andrew C. Walton

Theses and Dissertations

A Parallel Discrete Event Simulation Coprocessor was designed for conservative synchronization protocols and was implemented in software using some of a parallel computer's nodes to act as coprocessors. The coprocessor was designed to offload synchronization overhead and next event queue management from the nodes running the simulation. The coprocessor was designed to accelerate simulations based on the Simulation Protocol Evaluation on a Concurrent Testbed with ReUsable Modules (SPECTRUM) environment. The research was conducted in three steps: the SPECTRUM environment was ported from an Intel iPSC-2 to an Intel Paragon XP-S, the coprocessor was designed and the simulations were timed, with …


The Re-Engineering Of The Air Force Institute Of Technology Student Information System, Douglas J. Wu Dec 1994

The Re-Engineering Of The Air Force Institute Of Technology Student Information System, Douglas J. Wu

Theses and Dissertations

This research describes the design and implementation issues associated with re-engineering the Air Force Institute of Technology Student Information System (AFITSIS). Currently, AFITSIS executes on aging relational database technology and has unfriendly user interface mechanisms. The two research objectives met were to research current AFITSIS requirements, design, and implementation, and use object-oriented methods to design an alternative implementation based on proposed object database management system standards. This research explores how AFITSIS performance and capabilities might be enhanced by taking advantage of new object-oriented software engineering techniques. One of the primary benefits of this research is a detailed object modeling technique …


Embedology And Neural Estimation For Time Series Prediction, Robert E. Garza Dec 1994

Embedology And Neural Estimation For Time Series Prediction, Robert E. Garza

Theses and Dissertations

Time series prediction has widespread application, ranging from predicting the stock market to trying to predict future locations of scud missiles. Recent work by Sauer and Casdagli has developed into the embedology theorem, which sets forth the procedures for state space manipulation and reconstruction for time series prediction. This includes embedding the time series into a higher dimensional space in order to form an attractor, a structure defined by the embedded vectors. Embedology is combined with neural technologies in an effort to create a more accurate prediction algorithm. These algorithms consist of embedology, neural networks, Euclidean space nearest neighbors, and …


A Correlational Study Of The Sei's Capability Maturity Model And Software Development Performance In Dod Contracts, Robert M. Flowe, James B. Thordahl Dec 1994

A Correlational Study Of The Sei's Capability Maturity Model And Software Development Performance In Dod Contracts, Robert M. Flowe, James B. Thordahl

Theses and Dissertations

The Software Engineering Institute's (SEl's) Capability Maturity Model (CMM) is to measure an organization's software development process maturity. The Department of Defense (DoD) has model with the belief that a more mature software development process will result in a more successful software subject. Although there is a growing body of anecdotal evidence supporting this presumed correlation, there is empirical evidence. Thus, the goal of our research was to determine the nature of the correlation, if any, :ware process maturity and software project success, where process maturity is based on a CMM rating and success based on the parameters of cost …


Factors In Human-Computer Interface Design (A Pilot Study), Susan Stewart Dec 1994

Factors In Human-Computer Interface Design (A Pilot Study), Susan Stewart

Theses and Dissertations

The DoD has budgeted over $9.8 billion for 1995 for information technology, yet many government office workers let their existing systems sit idle. This thesis explores why these computers are sitting idle. This researcher's initial hypothesis was that certain features of the human-computer interface can positively or negatively affect efficiency, retention, and satisfaction level of workers. Although some research is being done in this area, interfaces continue to be of poor quality, especially in the DoD, where long procurement cycles, forced purchases, and limited budgets result in out-of-date software. Intuitively most programmers know the human-computer interface impacts on a person's …


Semantics Vs. Syntax Vs. Computations Machine Models For Type-2 Polynomial-Time Bounded Functionals (Preliminary Draft), James S. Royer Nov 1994

Semantics Vs. Syntax Vs. Computations Machine Models For Type-2 Polynomial-Time Bounded Functionals (Preliminary Draft), James S. Royer

Electrical Engineering and Computer Science - Technical Reports

This paper investigates analogs of the Kreisel-Lacombe-Shoenfield Theorem in the context of the type-2 basic feasible functionals, a.k.a. the Mehlhorn-Cook class of type-2 polynomial-time functionals. We develop a direct, polynomial-time analog of effective operation, where the time bound on computations is modeled after Kapron and Cook's scheme for their basic polynomial-time functionals. We show that (i) if P = NP, these polynomial-time effective operations are strictly more powerful on R (the class of recursive functions) than the basic feasible functions, and (ii) there is an oracle relative to which these polynomial-time effective operations and the basic feasible functionals have the …


A Case Tool Supporting The Moses Development Methodology, Florida International University Glupe Nov 1994

A Case Tool Supporting The Moses Development Methodology, Florida International University Glupe

FIU Electronic Theses and Dissertations

A new breed of CASE tools is taking advantage of object-oriented development. The CASE tool in this thesis will serve as a top-level guidance platform. The user will be able to follow an agenda in which his progress is recorded for each step of the development process. At the same time, the user will still be able to develop documents, diagrams and source code by using provided editors. The specific object-oriented methodology followed in this thesis is MOSES (Methodology for Object-Oriented Software Engineering of Systems). This advocates an iterative approach to development while providing both textual and graphical deliverables to …


Mccolm’S Conjecture, Yuri Gurevich, Neil Immerman, Saharon Shelah Nov 1994

Mccolm’S Conjecture, Yuri Gurevich, Neil Immerman, Saharon Shelah

Neil Immerman

Gregory McColm conjectured that positive elementary inductions are bounded in a class K of finite structures if every (FO + LFP) formula is equivalent to a first-order formula in K. Here (FO + LFP) is the extension of first-order logic with the least fixed point operator. We disprove the conjecture. Our main results are two model-theoretic constructions, one deterministic and the other randomized, each of which refutes McColm’s conjecture.


Multiprocessor Document Allocation: A Neural Network Approach, Abdulaziz Sultan Al-Sehibani, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka Nov 1994

Multiprocessor Document Allocation: A Neural Network Approach, Abdulaziz Sultan Al-Sehibani, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We consider the problem of distributing the documents to a given set of processors so that the load on each processor is as equal as possible and the amount of communication is as small as possible. This is an NP-Complete problem. We apply continuous as well as discrete Hopfield neural networks to obtain suboptimal solutions for the problem. These networks perform better than a genetic algorithm for this task proposed by Frieder et al. [4]; in particular, the continuous Hopfield network performs extremely well.


1.1, Yolanda Jones Nov 1994

1.1, Yolanda Jones

E-lert

No abstract provided.


Disk-Directed I/O For Mimd Multiprocessors, David Kotz Nov 1994

Disk-Directed I/O For Mimd Multiprocessors, David Kotz

Computer Science Technical Reports

Many scientific applications that run on today's multiprocessors are bottlenecked by their file I/O needs. Even if the multiprocessor is configured with sufficient I/O hardware, the file-system software often fails to provide the available bandwidth to the application. Although libraries and improved file-system interfaces can make a significant improvement, we believe that fundamental changes are needed in the file-server software. We propose a new technique, disk-directed I/O, that flips the usual relationship between server and client to allow the disks (actually, disk servers) to determine the flow of data for maximum performance. Our simulations show that tremendous performance gains are …


A Data-Parallel Programming Library For Education (Dapple), David Kotz Nov 1994

A Data-Parallel Programming Library For Education (Dapple), David Kotz

Computer Science Technical Reports

In the context of our overall goal to bring the concepts of parallel computing into the undergraduate curriculum, we set out to find a parallel-programming language for student use. To make it accessible to students at all levels, and to be independent of any particular hardware platform, we chose to design our own language, based on a data-parallel model and on C++. The result, DAPPLE, is a C++ class library designed to provide the illusion of a data-parallel programming language on conventional hardware and with conventional compilers. DAPPLE defines Vectors and Matrices as basic classes, with all the usual C++ …


Icdm: Integrated Cooperative Decision Making - In Practice, Leonard Myers, Jens G. Pohl Nov 1994

Icdm: Integrated Cooperative Decision Making - In Practice, Leonard Myers, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Multi-agent systems provide an attractive architecture for the implementation of complex systems. Much of the research is focussed on complete automation of the decision making process as a means of duplicating human abilities for working with new problems and environments. There as also a need for systems that employ the human as an agent and rely on human abilities for common sense and deep thought. The CAD Research Center at Cal Poly and CDM Technologies have significant experience in building systems of the latter type that assist human users in solving complex problems in planning, design and economics. This experience …


Multimedia Authoring, Development Environments, And Digital Video Editing, Fillia Makedon, James W. Matthews, Charles B. Owen, Samuel A. Rebelsky Nov 1994

Multimedia Authoring, Development Environments, And Digital Video Editing, Fillia Makedon, James W. Matthews, Charles B. Owen, Samuel A. Rebelsky

Dartmouth Scholarship

Multimedia systems integrate text, audio, video, graphics, and other media and allow them to be utilized in a combined and interactive manner. Using this exciting and rapidly developing technology, multimedia applications can provide extensive benefits in a variety of arenas, including research, education, medicine, and commerce. While there are many commercial multimedia development packages, the easy and fast creation of a useful, full-featured multimedia document is not yet a straightforward task.

This paper addresses issues in the development of multimedia documents, ranging from user-interface tools that manipulate multimedia documents to multimedia communication technologies such as compression, digital video editing and …


Devious: A Distributed Environment For Vision Tasks, Phillip R. Romig Iii, Ashok K. Samal Nov 1994

Devious: A Distributed Environment For Vision Tasks, Phillip R. Romig Iii, Ashok K. Samal

CSE Conference and Workshop Papers

We present a system for the integration of computer vision tasks in a distributed environment. This system, called DeViouS, is based on the client/server model and runs in a heterogeneous environment of Unix workstations. It takes advantage of the free cycles in modern workstation environments to distribute and speed up the execution of vision tasks.

Two primary goals of DeViouS are to provide a practical distributed system and a research environment for vision computing. DeViouS is based on a modular design that allows experimentation in various aspects of algorithm design, scheduling and network programming. It can make use of any …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 9, November 1994, College Of Engineering And Computer Science, Wright State University Nov 1994

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 9, November 1994, 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.


Characterization Of A Class Of Sigmoid Functions With Applications To Neural Networks, Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka Nov 1994

Characterization Of A Class Of Sigmoid Functions With Applications To Neural Networks, Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

Sigmoid functions, whose graphs are "S-shaped" curves, appear in a great variety of contexts, such as the transfer functions in many neural networks. Their ubiquity is no accident; these curves are the among the simplest non-linear curves, striking a graceful balance between linear and non-linear behavior.


Covering Radius 1985-1994, G. D. Cohen, S. N. Litsyn, Antoine C. Lobstein, H. F. Mattson Jr Nov 1994

Covering Radius 1985-1994, G. D. Cohen, S. N. Litsyn, Antoine C. Lobstein, H. F. Mattson Jr

Electrical Engineering and Computer Science - Technical Reports

We survey important developments in the theory of covering radius during the period 1985-1994. We present lower bounds, constructions and upper bounds, the linear and nonlinear cases, density and asymptotic results, normality, specific classes of codes, covering radius and dual distance, tables, and open problems.


Building Multimedia Proceedings: The Roles Of Video In Interactive Electronic Conference Proceedings, Samuel A. Rebelsky, Fillia Makedon, James Matthews, Charles Owen, Laura Bright, Kenneth Harker, Nancy Toth Nov 1994

Building Multimedia Proceedings: The Roles Of Video In Interactive Electronic Conference Proceedings, Samuel A. Rebelsky, Fillia Makedon, James Matthews, Charles Owen, Laura Bright, Kenneth Harker, Nancy Toth

Computer Science Technical Reports

Modern computer systems have changed the way that conference proceedings can be presented and archived. No longer are researchers limited by printed text; electronic proceedings allow one to search the proceedings, add and share annotations, and create paths of related concepts through the proceedings. These additional capabilities extend the opportunities and benefit the thought processes of actual conference participants and the new virtual participants who experience the conference through the electronic proceedings.

In this paper, we discuss the construction of electronic conference proceedings, highlighting the role of talks and other presentations (and, particularly, the audio and video of these talks …


Distributed Scheduling In Finite Capacity Networks, Perry Fizzano, Clifford Stein Nov 1994

Distributed Scheduling In Finite Capacity Networks, Perry Fizzano, Clifford Stein

Computer Science Technical Reports

We consider the problem of scheduling unit-sized jobs in a distributed network of processors. Each processor only knows the number of jobs it and its neighbors have. We give an analysis of intuitive algorithm and prove that the algorithm produces schedules that are within a logarithmic factor of the length of the optimal schedule given that the optimal schedule is sufficiently long.


Incremental Equational Programming, Samuel A. Rebelsky Nov 1994

Incremental Equational Programming, Samuel A. Rebelsky

Computer Science Technical Reports

This paper extends Equational Programming (EP)—a declarative, symbolic programming language—to allow programs to manipulate incrementally defined and modified input terms and to avoid repeated work when evaluating these incremental terms. This paper represents two key aspects of this extension: a notation for representing revision and a modification to EP's runtime library to accomodate this notation. Unlike Field's method of incremental term rewriting, which is designed for more general but less efficient term-rewriting systems, this paper's method accomodates EP's restrictions (in particular, EP's decision to disallow overlapping rules) so that it may take advantage of EP's speed.


Efficient Parallel Algorithms For Closest Point Problems, Peter Su Nov 1994

Efficient Parallel Algorithms For Closest Point Problems, Peter Su

Dartmouth College Ph.D Dissertations

This dissertation develops and studies fast algorithms for solving closest point problems. Algorithms for such problems have applications in many areas including statistical classification, crystallography, data compression, and finite element analysis. In addition to a comprehensive empirical study of known sequential methods, I introduce new parallel algorithms for these problems that are both efficient and practical. I present a simple and flexible programming model for designing and analyzing parallel algorithms. Also, I describe fast parallel algorithms for nearest-neighbor searching and constructing Voronoi diagrams. Finally, I demonstrate that my algorithms actually obtain good performance on a wide variety of machine architectures. …