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Theses and Dissertations

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Full-Text Articles in Computer Sciences

Object-Oriented Database Access From Ada, Li Chou Mar 1993

Object-Oriented Database Access From Ada, Li Chou

Theses and Dissertations

Ada embodies many modern software engineering principles, namely, modifiability, efficiency, reliability, and understandability. Its powerful data abstraction allows programmers to easily model objects in the real world. A database management system (DBMS) provides long term storage. It provides a convenient and efficient environment to manipulate data. Currently, with Ada access to a DBMS is typically done through the use of a language extension and a preprocessor to convert the extensions to library calls appropriate for the DBMS. However, these systems are limited on more complex applications, such as computer-aided engineering design. Object-oriented design (OOD) is a new way of thinking …

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Toward Reusable Graphics Components In Ada, Sam-Kyu Lim Mar 1993

Toward Reusable Graphics Components In Ada, Sam-Kyu Lim

Theses and Dissertations

This thesis demonstrates and illustrates a way of developing reusable graphics software components in Ada associated with a C++/C library. The work was carried out using object-oriented software development techniques that were used to analyze, design and implement a partial flight simulator. The objective of this thesis was to present a way of building reusable software components with Ada in a graphics application environment. An object-oriented approach was taken in the development of a set of reusable graphics software components for a flight simulator domain. A selection of a set of reusable software components came from domain analysis. These components …

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A Distributed Object-Oriented Database Application Design, Hsin-Feng Edward Wu Mar 1993

A Distributed Object-Oriented Database Application Design, Hsin-Feng Edward Wu

Theses and Dissertations

The purpose of this study is to analyze and develop a distributed object-oriented database management system (DOODBMS) application to support parallel software development of the Parallel Algorithms and Applications Group (PAAG) at AFIT. By following the software lifecycle of object-oriented paradigm, this thesis investigation is intended to generate requirements analysis, design, implementation, user interface design and implementation, and integration of the database application with the user interface. ITASCA, an existing DOODBMS platform, has been chosen to prototype the application for its distribution functionalities and object-oriented modeling power. The user interface of the database application is based on X-window OSF/Motif front-end …

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Development Of A Visual System Interface To Support A Domain-Oriented Application Composition System, Timothy L. Weide Mar 1993

Development Of A Visual System Interface To Support A Domain-Oriented Application Composition System, Timothy L. Weide

Theses and Dissertations

This research designed and prototyped a visual system interface to generate, display, and modify domain-oriented application specifications. A visual system interface, called the Architect Visual System Interface (AVSI), supplements a text-based environment, called Architect, previously developed by two other students. 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 its correctness before any programming language specific code is generated. This thesis investigates visual techniques for populating, manipulating, viewing, and composing these software application specifications within the formal object base scheme required …

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An Immersive Synthetic Environment For Observation And Interaction With A Large Volume Of Interest, Rex G. Haddix Iii Mar 1993

An Immersive Synthetic Environment For Observation And Interaction With A Large Volume Of Interest, Rex G. Haddix Iii

Theses and Dissertations

This thesis addresses the initial development of a Synthetic Battlebridge System designed to provide the user with a synthetic three- dimensional view of moving and stationary vehicles dispersed over a hundred thousand cubic mile volume. The system contains provisions to allow a user to view the battlefield either in the Polhemus LookingGlass™ fiber optic based high resolution head mounted display, a standard CRT, or through the Fake Space Labs BOOM2M™ high resolution monochrome display. Users can also video tape a session in the Synthetic Battlebridge System. A voice recognition system provides user interaction to the Synthetic Battlebridge System. Using a …

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Rendering The Out-The-Window View For The Afit Virtual Cockpit, W. Dean Mccarty Mar 1993

Rendering The Out-The-Window View For The Afit Virtual Cockpit, W. Dean Mccarty

Theses and Dissertations

The Air Force Institute of Technology (AFIT) is developing a distributed interactive flight simulator, the Virtual Cockpit, using commercial graphics workstations and helmet mounted displays. The Virtual Cockpit communicates with other simulators via local and long-haul networks using the SIMNET protocol. The work reported in this thesis focuses on developing the terrain database for the synthetic environment and on rendering the pilot's view of the database. There are many different file formats for describing 3- dimensional geometric polygonal objects. An analysis of three formats, AFIT GEOM, the Naval Postgraduate School (NPS) DRP, and Software Systems' Flight, is presented. Each file …

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Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr. Jan 1993

Weapon System Integration For The Afit Virtual Cockpit, William E. Gerhard Jr.

Theses and Dissertations

The Air Force Institute of Technology is continuing research in the Virtual Cockpit. The Virtual Cockpit makes use of high performance graphics workstations, Virtual Environment technology, and Distributed Interactive Simulation network protocols to create a flight simulator based on the capabilities of the McDonnell Douglas F-15E Strike Eagle. The work presented in this thesis focuses on the design and implementation issues for integrating a weapons delivery capability. Weapons simulated include: RADAR and IR guided air- to-air missiles, gravity and precision guided bombs, and a 20mm cannon. Virtual Environment displays used include: color NTSC and monochrome high resolution helmet mounted displays …

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Object-Oriented Analysis, Design, And Implementation Of The Saber Wargame, David S. Douglass Dec 1992

Object-Oriented Analysis, Design, And Implementation Of The Saber Wargame, David S. Douglass

Theses and Dissertations

Saber is a two-sided, air and land war game that simulates decisions made of commanders at the theater-level. It is being developed by the Air Force Institute of Technology for the Air Force Wargaming center at Maxwell AFB, Alabama. Saber models conventional, chemical, and nuclear warfare between aggregated air and land forces. It also portrays the effects of logistics, satellites, weather, terrain, and intelligence which add to the realism of the Saber war game. The Saber war game has three main components, the preprocessor. which is responsible for scenario development and pregame activities, the simulation. the guts of the war …

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A User Interface To A True 3-D Display Device, Bruce A. Hobbs Dec 1992

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. …

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A Vhdl Interpreter For Model-Based Diagnoses, David R. Griffin Dec 1992

A Vhdl Interpreter For Model-Based Diagnoses, David R. Griffin

Theses and Dissertations

Model-based reasoning permits diagnostic applications to be written without waiting for someone to become an 'expert' of the system. For model-based diagnostics, there must be a model to reason from. This thesis explores using a VHDL description of the system as that model. A system based around a VHDL interpreter was written specifically for a model-based diagnostic algorithm. Currently, the diagnostic system uses an algorithm by Dries. This algorithm was derived from Scarl's Full Consistency Algorithm. The system was designed to be modular so that different diagnostic techniques could be implemented. It is divided into three parts: a VHDL parser, …

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Solution To A Multicriteria Aircraft Routing Problem Utilizing Parallel Search Techniques, James J. Grimm Iii Dec 1992

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 …

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Creating And Manipulating A Domain-Specific Formal Object Base To Support A Domain-Oriented Application Composition System, Mary Anne Randour Dec 1992

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 …

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Creating And Manipulating Formalized Software Architectures To Support A Domain-Oriented Application Composition System, Cynthia G. Anderson Dec 1992

Creating And Manipulating Formalized Software Architectures To Support A Domain-Oriented Application Composition System, Cynthia G. Anderson

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 its correctness before any programming language specific code is generated. Architect depends upon the existence of a formal object base (or domain model) which was investigated by another student in related research. The research described in this thesis relied on …

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Entity-Relationship Versus Object-Oriented Modeling And The Underlying Dbms, Kevin J. Routhier Dec 1992

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 …

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Ada Implementation Of An Object Data Repository, Stephen P. Perucca Dec 1992

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 …

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Management Of Simnet And Dis Entities In Synthetic Environments, Steven M. Sheasby Dec 1992

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 …

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Efficient Derivation And Approximations Of Cepstral Coefficients For Speech Coding, Kimberly A. Limcangco Dec 1992

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).

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A Synthetic Environment Flight Simulator: The Afit Virtual Cockpit, John C. Switzer Dec 1992

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.

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A Unified Model Of Program Behavior, Douglas T. Michel Dec 1992

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 …

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A Synthetic Environment For Satellite Modeling And Satellite Orbital Motion, David L. Pond Dec 1992

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 …

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Version And Transaction Management In Osmagic: An Object-Oriented Database Implementation Of The Magic Vlsi Layout Design Tool, Gary M. Lightner Dec 1992

Version And Transaction Management In Osmagic: An Object-Oriented Database Implementation Of The Magic Vlsi Layout Design Tool, Gary M. Lightner

Theses and Dissertations

The goal of this thesis was to study the feasibility of using an object-oriented database management system to provide the functionality and performance needed to support a complex computer-aided design tool. We do this by modifying OSMagic, a prototype system of the Magic very large scale integrated (VLSI) circuit design tool implemented on the ObjectStore object- oriented database management system. OSMagic was changed to support three different interfaces to ObjectStore and to work in a networking environment. We then designed and examined the use of version and transaction management models as a means of addressing the weaknesses of the prototype …

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An Intelligent Real-Time System Architecture Implemented In Ada, Michael A. Whelan Dec 1992

An Intelligent Real-Time System Architecture Implemented In Ada, Michael A. Whelan

Theses and Dissertations

Conventional real-time systems are fully deterministic allowing for off-line, optimal, task scheduling under all circumstances. Real-time intelligent systems add non-deterministic task execution times and non- deterministic task sets for scheduling purposes. Non-deterministic task sets force intelligent real-time systems to trade-off execution time with solution quality during run-time and perform dynamic task scheduling. Four basic design considerations addressing those tradeoffs have been identified: control reasoning, focus of attention, parallelism, and algorithm efficacy. Non-real- time intelligent systems contain an environment sensor, a model of the environment, a reasoning process, and a large collection of procedural processes. Real-time intelligent systems add to these …

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Formalization And Transformation Of Informal Analysis Models Into Executive Refine™ Specifications, Mary M. Boom, Bradley D. Mallare Dec 1992

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 …

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A Model For Determining Task Set Schedulability In The Presence Of System Effects, Rusty O. Baldwin Dec 1992

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 …

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Power Analysis In Flexible Automation, Nathan A. Titus Dec 1992

Power Analysis In Flexible Automation, Nathan A. Titus

Theses and Dissertations

The performance of an automation or robotic device can be measured in terms of its power efficiency. Screw theory is used to mathematically define the task instantaneously with two screws. The task wrench defines the effect of the device on its environment, and the task twist describes the motion of the device. The tasks can be separated into three task types: kinetic, manipulative, and reactive. Efficiency metrics are developed for each task type. The output power is strictly a function of the task screws, while device input power is shown to be a function of the task, the device Jacobian, …

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Comparison Of Artificial Neural Networks With A Conventional Heuristic Technique For Optimization Problems, Jeffrey S. Gruner Dec 1992

Comparison Of Artificial Neural Networks With A Conventional Heuristic Technique For Optimization Problems, Jeffrey S. Gruner

Theses and Dissertations

This research investigates the utility of the Hopfield and Kohonen artificial neural networks to the traveling salesman optimization problem. A third, non-neural-network technique (the Christofides Algorithm - a competitive, bounded-solution operations research technique) is also investigated for comparison to the artificial neural network solutions. An eight and forty-two city distribution are chosen for comparison of the solutions.

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Recurrent Neural Networks For Radar Target Identification, Eric T. Kouba Dec 1992

Recurrent Neural Networks For Radar Target Identification, Eric T. Kouba

Theses and Dissertations

A real-time recurrent learning algorithm was applied to a five class radar target identification problem. The wideband radar was assumed to measure both kinematic (tracking information expressed as estimated aspect angles) and high range resolution data from a single, isolated aircraft. The aspect angles (azimuth and elevation) of the aircraft relative to the radar were assumed to be constantly chancing. This created temporal sequences of high range resolution radar signatures that changed as the aspect angles changed. These sequences were used as input features to a recurrent neural network for three radar target identification test cases. The first test case …

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Software Support Measurement And Estimating For Oracle Database Applications Using Mark Ii Function Points, Steven D. Radnov Dec 1992

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 …

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An Assessment Of Software Safety As Applied To The Department Of Defense Software Development Process, Peter W. Colan, Robert W. Prouhet Dec 1992

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 …

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Formalizing, Validating, And Verifying Real-Time System Requirements With Reacto And Vhdl, Frank C. Young Dec 1992

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 …

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