Physical Sciences and Mathematics Commons^™

A Model For Determining Task Set Schedulability In The Presence Of System Effects, Rusty O. Baldwin

Theses and Dissertations

This research developed a parameterized model that accounts for system overhead and determines when an Ada runtime environment can no longer successfully execute a given Ada task set and still meet all deadlines. The Ada Compiler Evaluation Capability benchmark was used to characterize an actual runtime environment. Using that data, a generic model of a preemptive, rate monotonic priority based runtime system was developed which accounts for overhead due to clock updates, context switching, task suspension, and synchronization. Validation was based on the Hartstone benchmark. First, the benchmark was executed using, the actual runtime environment. Then, those results were compared …

Formalization And Transformation Of Informal Analysis Models Into Executive Refine™ Specifications, Mary M. Boom, Bradley D. Mallare

Theses and Dissertations

This research developed and implemented an automated technique for translating informal specifications into formal, executable specifications. A unified Abstract Model (UAM) was developed to combine the information contained in Entity Relationship, State Transition, and Data Flow Models into a concise, object-based representation. The UAM forms the basis for defining a formal language, the Object Modeling Language (OML), used to capture the information contained in the UAM. By using OML, we were able to develop an automated translation process to convert informal specifications into executable, formal specifications. The Software Refinery Development Environment enabled us to easily develop a parser that translates …

Efficient Derivation And Approximations Of Cepstral Coefficients For Speech Coding, Kimberly A. Limcangco

Theses and Dissertations

A new formulation is presented for the calculation of cepstral coefficients directly from measured sine wave amplitudes and frequencies of speech waveforms. Approximations to these cepstral coefficients are shown to be suitable for operation in a real-time speech coding environment. These results were encoded in the C programming language and then evaluated through experiments that were conducted on the McAulay-Quatieri Sinusoidal Transform Coder (STC).

A Synthetic Environment For Satellite Modeling And Satellite Orbital Motion, David L. Pond

Theses and Dissertations

Analysts tasked to study satellites moving in space must often rely on photographs to conduct their analysis. Often these photographs do not adequately represent how satellites move in space, their spatial relationships, or their interaction with other satellites. What analysts need is a three- dimensional synthetic environment that depicts satellites as they actually move and interact in space. This thesis addresses the early development of the Satellite Modeler (SM), a system that allows analysts to study, satellite motion and maneuvering of computer aided design (CAD) models of those satellites in a three-dimensional orbit. The system contains equipment that allows analysts …

X-Aaarf An X Windows Version Of The Afit Algorithm Animation Research Facility, Charles R. Wright Jr.

Theses and Dissertations

The AFIT Algorithm Animation Research Facility was developed by the Air Force Institute of Technology (AFIT) as a teaching aid for data structures and algorithm design of sequential processes. However, AAARF's unique design makes it particularly suitable for the animation of algorithms running on remote systems. In particular, an extensive set of parallel performance animations has been developed for the Intel iPSC/2 Hypercube for parallel program analysis and performance optimization. The AAARF system was originally developed using the Sun Microsystems' SunView(TM) windowing system. Recent advances in Graphical User Interface (GUI) technology combined with Sun's adoption of the X Window System …

Formalizing, Validating, And Verifying Real-Time System Requirements With Reacto And Vhdl, Frank C. Young

Theses and Dissertations

We develop a methodology for formalizing, verifying, and validating the requirements specification of real-time systems based on a graphical and formal hierarchical Finite State Machine (FSM) language Reacto. We define a means to quantify time and express real-time constraints in Reacto and a transformation from Reacto to the Very High Speed Integrated Circuit (VHSIC) hardware Description Language (VHDL). Reacto's high level abstractions, graphical nature, and theorem prover produce efficient, accurate, and easily understood specifications. We use VHDL's event driven simulation capability, concurrency, and temporal operators to thoroughly examine temporal dependencies between the state machine transitions, and to increase simulation power …

Face Recognition With Neural Networks, Dennis L. Krepp

Theses and Dissertations

This study investigated neural networks for face verification and classification. The research concentrated on developing a neural network based feature extractor and/or classifier to perform authorized user verification in a realistic work environment. Recognition accuracy, system assumptions, training time, and execution time were analyzed to determine the feasibility of a neural network approach. Data was collected using a camcorder and two segmentation schemes: manual segmentation and motion-based, automatic segmentation. Data consisted of over 2000. 32x32 pixel, 8 bit gray scale images of 52 subjects; each subject had two to ten days worth of images collected. Several training and test sets …

Automated Logistics Information Systems: A Case Study, James E. Hogue

Theses and Dissertations

A change within the Air Force has shifted management responsibilities within the logistics community. Formerly diverse functions have come under the purview of a single manager-the Logistics Group Commander-who has inherited information systems that may riot be able to provide consolidated information for informed and accurate decision making. The purpose of this thesis was to describe the current and potential ability for three logistics information management systems to share data: Standard Base Supply System, Consolidated Aircraft Management System, and On-Line Vehicle Information Management System. A systems model was synthesized from the literature review to determine what components of a system …

The Adaptation Of The Sei's Capability Maturity Model To The Air Force Software Acquisition Management Process, William G. Dickerhoff Jr., William J. Sommers

Theses and Dissertations

This study develops an Air Force Software Acquisition Maturity Framework (SAMF) by adapting the Software Engineering Institute's (SEI) capability Maturity Model (CMM) to the Air Force software acquisition process. The SAMFs purpose is to provide the Air Force Materiel Command's product centers and program off ices with criterion to assess their software acquisition maturity in a similar fashion as the SEI's CMM provides companies a benchmark to measure their organization's software production maturity. The research was accomplished through a combination of information gathering techniques and data analysis. A literature search of documentation, both within and external to the Department of …

An Investigation Of Discovery-Based Learning In The Route Planning Domain, Freeman A. Kilpatrick Jr.

Theses and Dissertations

This thesis presents MAVERICK, a Discovery-Based learning (DBL) system designed to learn maneuvers in the route planning domain. DBL was originally designed to learn in domains for which little domain knowledge exists. This thesis proposes using it in domains for which knowledge exists, but the acquisition of this knowledge is difficult or time-consuming because of the knowledge acquisition bottleneck. The operation of the DBL process in MAVERICK was investigated to determine the potential utility of such a system to a real- world Air Force problem in the domain of aircraft route planning. MAVERICK worked well in its limited domain, and …

An Assessment Of Software Safety As Applied To The Department Of Defense Software Development Process, Peter W. Colan, Robert W. Prouhet

Theses and Dissertations

This research analyzed the relationships between the DOD software development process, system safety requirements, and current structured software safety analysis techniques. The current state of software safety was assessed within the aerospace industry and DOD, and a training program for DOD System Safety Managers was developed. A telephone survey was conducted to gather information on current software safety analysis techniques and methodologies. Personal interviews were conducted with Aeronautical System Center System Safety Managers to gather data on job perception and perceived training needs. The results of the study indicate that the DOD guidance and policy documents needed to implement and …

Integrated Diagnostic Expert System Model (Idesm): A Model For The Conversion Of Fault Isolation Procedures Into An Integrated Diagnostic Expert System, Robert J. Lacey, Glen D. Steemson

Theses and Dissertations

The purpose of this research was to develop a model to convert existing hardcopy maintenance manual fault isolation procedures into electronic format and to partially automate the fault isolation process. A comprehensive model was developed which comprised four major components: user interface, expert system submodel, hypermedia submodel, and a submodel integration shell. Using this model, the F 15E nose landing gear fault isolation procedures were transformed into a rule based expert system. An existing hypermedia information base was expanded and subsequently integrated with the expert system to form the prototype application. The prototype was evaluated by engineering and maintenance personnel …

Creating And Manipulating A Domain-Specific Formal Object Base To Support A Domain-Oriented Application Composition System, Mary Anne Randour

Theses and Dissertations

This research investigated technology which enables sophisticated users to specify, generate, and maintain application software in domain-oriented terms. To realize this new technology, a development environment, called Architect, was designed and implemented. Using canonical formal specifications of domain objects, Architect rapidly composes these specifications into a software application and executes a prototype of that application as a means to demonstrate is correctness before any programming language specific code is generated. This thesis investigated populating and manipulating the formal object base required by Architect. This object base is built using a domain- specific language (DSL) which serves as an interface between …

A Generic Template Extractor (Gentex) In C For Vlsi Design Verification, Kenneth J. Mcclellan Jr.

Theses and Dissertations

The problem of VLSI design verification through circuit extraction was analyzed. The problems of creating a simple template format, the permutability of pins, maintaining connectivity, and performance were focused on. A generic template extractor (GENTEX) was developed in the C programming language for use as a testbed to find solutions to these problems. Six different extraction algorithms were tested with GENTEX and compared based on performance. EDIF translation programs were used to interface with GENTEX on both the input and output sides. One translation program converted an EDIF representation of a schematic into the template format used by GENTEX. The …

Etann Hardware Implementation For Radar Emitter Identification, James B. Calvin Jr.

Theses and Dissertations

This study investigated classification of 30 radar emitters with 16 signal features using Intel's 80170NX chip, the Electronically Trainable Analog Neural Network (ETANN). Software tools were developed to characterize the ETANN sigmoidal transfer function for use in a custom simulator, known as Neural Graphics. Neural Graphics operates on a Silicon Graphics workstation. The Intel Neural Network Training System simulators were used in early experiments, but were found to be inefficient in training on data used in this research. Using a modified Neural Graphics simulator, single chip and multi-chip experiments were performed to provide benchmark results prior to performing chip-in-loop training. …

Management Of Simnet And Dis Entities In Synthetic Environments, Steven M. Sheasby

Theses and Dissertations

This thesis describes the techniques used to create an object manager utilized by an application program during a distributed interactive simulation. This work is currently utilized by a number of AFIT synthetic environment applications for use during a SIMNET exercise. An extensive review of distributed interactive simulations is presented. A discussion of the current distributed simulation protocol, SIMNET, is presented along with the future protocol standard, DIS. Finally, a brief discussion on dead reckoning and its importance during an exercise is presented. An analysis of the SIMNET and DIS protocols provided the basis for the creation of a series of …

An Object-Oriented Computer Aided Design Program For Traditional Control Systems Analysis, Wayne E. Bell

Theses and Dissertations

This thesis is a continuation of the ICECAP-PC research project conducted under Prof. Gary B. Lamont at the Air Force Institute of Technology. It is an ongoing development of a public domain Computer Aided Design package for Control Engineering and Digital Signal Processing students, faculty and practitioners with a special emphasis on education. This investigation begins with the software maintenance task of restructuring, debugging, and testing the functional version of ICECAP-PC 9.0. The continuous, traditional portions are then ported to a new object-oriented program structure which is the primary focus of this effort. New interactive graphics capabilities are then added …

Software Support Measurement And Estimating For Oracle Database Applications Using Mark Ii Function Points, Steven D. Radnov

Theses and Dissertations

This study investigated the results of measuring software support of Oracle database applications and estimating the effort and schedule required to provide support. Software measurement was accomplished with a variant of the function points metric, called Mark II function points, which is comprised of three weighted parameters, inputs, entities, and outputs. A technique for mapping Mark II function points to Oracle DBMS components was developed, and the size of the software support for each project, per team, was measured by tabulating and weighting the number of inputs, entities, and outputs that are added, changed, and/or deleted. Software support effort was …

Solution To A Multicriteria Aircraft Routing Problem Utilizing Parallel Search Techniques, James J. Grimm Iii

Theses and Dissertations

Pilots select routes based on factors such as threats, fuel, time on target, distance, and refueling points. This is a time consuming task. This thesis presents the software engineering synthesis of a software tool, based on a parallelized A* search algorithm, to select routes. For simplicity only threats and distance are used. A centralized open list is used with one processor managing the list while the other processors perform the node expansions. This decomposition result in a dynamically load balanced system. A number of parameters are changed to study their impact on the execution time. The use of a branch …

A User Interface To A True 3-D Display Device, Bruce A. Hobbs

Theses and Dissertations

This thesis describes an interactive interface to a true three dimensional, real-dm dynamic graphic display, the TI Omniview™. The system generates true 3-D images of volumetric data and objects. The TI Omniview is a cylindrical volumetric laser display that uses a rotating double-helix translucent disk to fill the display cylinder. Voxels are illuminated on the 2-D surface. The rotational speed of the disk allows the viewer to fuse the 2-D images into a true 3-D image. The interface provides the user with a quick and flexible means of manipulating the image generated, the sub-volume displayed, and the resulting 3-D image. …

Pargal: A Package For Parallel Graph Algorithms, Winston Anand-Kumar

Masters Theses

In this thesis, we have considered three graph problems namely, spanning forest problem, connected component problem and minimum cost spanning forest problem. Standard methods to solve these problems using sequential algorithms by various authors are presented for each problem. Efficient parallel algorithms for these problems have also been presented by various authors; however, most of these solutions demands a need for large number of processors, which immediately increases the cost of the hardware and in most of the cases it seems not very practical.

We present efficient solutions for the three problems on a hypercube parallel computer using p processors. …

A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu

Masters Theses

A probabilistic model was utilized to simulate the brown stock washing system's error due to process variability and measurement noise. Mass balances of the washing system were performed using distribution sampling. This model relies on a nonlinear relationship between displacement and dilution, which permitted the generation of displacement ratio based upon wash liquor ratio. Experimental trials were performed on a pilotscale rotary vacuum single-stage washer. Nonlinear first-order relationship appears to characterize a pilotscale washer adequately. Differences were observed between the means and standard deviations of the measured results compared to the simulation output. Future work is needed to identify the …

Ada Implementation Of An Object Data Repository, Stephen P. Perucca

Theses and Dissertations

The many benefits of object-oriented software development such as encapsulation and extendibility have inspired numerous models of the object- oriented paradigm. Rumbaugh's Object Modeling Technique (OMT) is an object- oriented model that uses three submodels. The object, dynamic, and functional submodels of the OMT describe the data, behavioral, and processing aspects of a system by using entity-relationship, state-transition, and data flow models. Cross-links relate how the three submodels tie together. Two metamodels (models of models) of the OMT are developed using the OMT methodology and notation. The essential data elements of the OMT are abstracted into a data metamodel, and …

A Synthetic Environment Flight Simulator: The Afit Virtual Cockpit, John C. Switzer

Theses and Dissertations

This thesis describes the design and implementation of a part of the Virtual Cockpit: a synthetic environment, distributed network flight simulator. The goal of the project was to prove the concept that this type of flight simulator could fill the gap between high-end, very expensive flight simulators and low-end game quality flight simulators. Discussed are: object-oriented design techniques, multi-processor utilization, the flight dynamics model, synthetic environment technology, the frame-rate vs. realism issue, and the interfaces to a realistic joystick and throttle.

Design Recovery For Software Library Population, Chester A. Wright Jr.

Theses and Dissertations

This thesis research investigated design recovery as a means of populating a reuse library. The targeted library was part of the Automatic Programming Technologies for Avionics Systems (APTAS). APTAS uses a knowledge base of forms, to present questions to a user, and rules, to select the forms to present and choose existing library modules to use in composing a new system. The approach applied the reengineering model developed by Eric Byrne to accomplish planning for the project, expanded the renovation phase of this model to cover the actual design recovery, and applied the expanded model to populating the library. Using …

Generalization And Parallelization Of Messy Genetic Algorithms And Communication In Parallel Genetic Algorithms, Laurence D. Merkle

Theses and Dissertations

Genetic algorithms (GA) are highly parallelizable, robust semi- optimization algorithms of polynomial complexity. The most commonly implemented GAs are 'simple' GAs (SGAs). Reproduction, crossover, and mutation operate on solution populations. Deceptive and GA-hard problems are provably difficult for simple GAs. Messy GAs (MGA) are designed to overcome these limitations. The MGA is generalized to solve permutation type optimization problems. Its performance is compared to another MGA's, an SGA's, and a permutation SGA's. Against a fully deceptive problem the generalized MGA (GMGA) consistently performs better than the simple GA. Against an NP-complete permutation problem, the GMGA performs better than the other …

Real Image Visual Display System, James R. Brandt

Theses and Dissertations

This thesis investigates a technique for improving the perception of three-dimensionality in images generated by a Silicon Graphics workstation. The technique involves using a spherical mirror into which the graphics from the CRT are projected. A real image of the graphic is formed by the mirror and it appears to be floating at the image plane. The three-dimensional effect is improved by adding reflections or shadows of the displayed object. Additionally, a method of using real objects with computer generated shadows and computer generated objects with real shadows is investigated. This is done in an effort to quantify how far …

A Unified Model Of Program Behavior, Douglas T. Michel

Theses and Dissertations

This thesis is an attempt to account for and unify the three types of locality: temporal, spatial, and structural. A diverse sample of traces are used in measuring program behavior with respect to these localities and a model is presented which represents the memory references a program generates as it goes through execution. The model is validated by estimating, the entropy of a synthetically generated trace and comparing it with actual traces. The results indicate that there is more predictability contained in the original trace than what the model was able to capture. Different variations of the model were tried …

Entity-Relationship Versus Object-Oriented Modeling And The Underlying Dbms, Kevin J. Routhier

Theses and Dissertations

Despite the impressive accomplishments in relational database research, greater support is needed for persistence of the new types of data encountered with object-oriented programming. The concept of object-orientation is not new in the realm of programming; however, its utilization in database management systems is still immature. Regardless of this fact, there is an urgency for object-oriented database technology. With this increase in demand for the next generation databases comes the need to examine object-oriented data modeling versus the conventional entity-relationship modeling of relational database design. This thesis objective is to analyze both paradigms to determine if object-oriented modeling can significantly …

On The Difficulty Of Manhattan Channel Routing, Ronald I. Greenberg, Joseph Jaja, Sridhar Krishnamurthy

Computer Science: Faculty Publications and Other Works

We show that channel routing in the Manhattan model remains difficult even when all nets are single-sided. Given a set of n single-sided nets, we consider the problem of determining the minimum number of tracks required to obtain a dogleg-free routing. In addition to showing that the decision version of the problem isNP-complete, we show that there are problems requiring at least d+Omega(sqrt(n)) tracks, where d is the density. This existential lower bound does not follow from any of the known lower bounds in the literature.