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Establishing A Methodology For Evaluation And Selecting Computer Aided Software Engineering Tools For A Defined Software Engineering Environment At The Air Force Institute Of Technology School Of Engineering, Jody L. Mattingly
Theses and Dissertations
This thesis identifies the software engineering environment (SEE) as it exists at the Air Force Institute of Technology (AFIT) School of Engineering. It also describes the software process model employed and the software development methods presented as part of the curriculum. Based on this information, criteria was established to evaluate computer aided software engineering (CASE) tools being considered for integration into the SEE. Each criterion was weighted to indicate its importance when selecting CASE tools. The criteria were further used to establish a methodology to be used to evaluate and select the CASE tools under consideration as well as future …
Effect Of Spatial Locality Prefetching On Structural Locality, Dirk D. Schalch
Effect Of Spatial Locality Prefetching On Structural Locality, Dirk D. Schalch
Theses and Dissertations
The purpose of this research was to analyze the effect that spatial locality prefetching in cache memory has on the structural locality of program memory referencing behavior. To examine this, a software simulator was built to model a proposed two-level cache memory subsystem. The proposed subsystem was designed to use spatial locality prefetching to exploit the structural locality contained in executing computer workloads. New memory referencing models were developed to incorporate the combined use of structural locality and spatial locality prefetching. From these models, equations were derived to predict the hit rates for both caches. Combined with the state transition …
Speech Recognition Using Multiple Features And Multiple Recognizers, Thomas F. Rathbun
Speech Recognition Using Multiple Features And Multiple Recognizers, Thomas F. Rathbun
Theses and Dissertations
The purpose of this thesis is to demonstrate the feasibility of using multiple features and multiple recognizers to perform isolated word recognition. This is accomplished by performing multiple independent recognition tests and fusing the results together to get a single recognition result. The speech data is recorded and each word is extracted into a separate file. Eight features are calculated for each word. The features are calculated on 512 sample time slices and produce 16 component vector output. The three recognizers use the eight features to produce a total of 24 error distance lists. These lists are then fused together …
Three-Dimensional Medical Image Registration Using A Patient Space Correlation Technique, Patrick J. Rizzuto Jr.
Three-Dimensional Medical Image Registration Using A Patient Space Correlation Technique, Patrick J. Rizzuto Jr.
Theses and Dissertations
The routine clinical use of three-dimensional data provided by modern medical imaging procedures is often impeded by the difficulty in accurately correlating the resultant volume datasets. These data are frequently obtained at different times using the same modality, or images of the same patient are sometimes produced using more than one imaging modality. In order to analyze the similarities and differences between such images, it is necessary for the medical imaging data to be spatially aligned using a process known as image registration. This research investigated a structure-based image registration technique based upon simple, three-dimensional relationships among user identified landmarks. …
Design Of Style-V — A Translator To Convert Standard Vhdl Into A Stylized Form For Automated Microcode Generation, Dennis A. Rumbley
Design Of Style-V — A Translator To Convert Standard Vhdl Into A Stylized Form For Automated Microcode Generation, Dennis A. Rumbley
Theses and Dissertations
This thesis provides an analysis and preliminary design of Style V, a source-to-source computer language translator. Style-V converts IEEE standard VHDL into a special style of VHDL defined for a commercial tool, the Integrated Design Automation System (IDAS). Thirteen mappings between standard VHDL and the IDAS subset were identified. The mappings were analyzed using Domain Analysis and Modern Structured Analysis techniques. Four processes covering several of the mappings were completely analyzed. One mapping to convert CASE statements to IF statements was implemented. Since the IDAS restricts designs to bit logic, a method for representing multilevel logic with bit logic was …
A Spatially Partitioned Parallel Simulation Of Colliding Objects, Robert S. Moser
A Spatially Partitioned Parallel Simulation Of Colliding Objects, Robert S. Moser
Theses and Dissertations
This study investigated the application of a conservative synchronization paradigm to the classical, distributed pool balls simulation executed on an eight node, Intel iPSC/2 hypercube. Wieland's concept of spatial partitioning and limited data replication was used. Analysis has shown that 100% parallelization of execution is possible in a conservative environment via assignment of multiple sectors to nodes. Two conservative formulations for minimum safe time were derived. A tradeoff exists between scalability and efficiency. Optimum sectoring prediction has been shown possible through application of linear regression techniques. The results of this research reveal that a conservative approach to distributed, discrete event …
Improved Task Scheduling For Parallel Simulations, Andrew E. Mcnear
Improved Task Scheduling For Parallel Simulations, Andrew E. Mcnear
Theses and Dissertations
The objective of this investigation is to design, analyze, and validate the generation of optimal schedules for simulation systems. Improved performance in simulation execution times can greatly improve the return rate of information provided by such simulations resulting in reduced development costs of future computer/electronic systems. Optimal schedule generation of precedence-constrained task systems including iterative feedback systems such as VHDL or war gaming simulations for execution on a parallel computer is known to be N P-hard. Efficiently parallelizing such problems takes full advantage of present computer technology to achieve a significant reduction in the search times required. Unfortunately, the extreme …
An Application Of The Object-Oriented Paradigm To A Flight Simulator, Dennis J. Simpson
An Application Of The Object-Oriented Paradigm To A Flight Simulator, Dennis J. Simpson
Theses and Dissertations
This thesis describes the object-oriented software development techniques that were used to analyze, design and implement a flight simulator. The objective of this thesis was to present a comprehensive object-oriented software development methodology and show how it was used in constructing an actual application. An extensive review of current object-oriented practices is presented along with the methods that were used to take the flight simulator from analysis to design and through to implementation. The description of the methodology concentrates upon the design and implementation phases of the object-oriented software lifecycle. Examples from the design of the flight simulator demonstrate how …
A Hybrid Approach To Battlefield Parallel Discrete Event Simulation, Steven R. Soderholm
A Hybrid Approach To Battlefield Parallel Discrete Event Simulation, Steven R. Soderholm
Theses and Dissertations
This thesis describes a method of parallelizing a battlefield discrete event simulation. The method combines elements of conservative time synchronization together with elements of optimistic computation and local rollback on a message passing hardware architecture. The battle simulation features aircraft moving in a battle area and launching missiles at enemy aircraft. Aircraft are randomly grouped into logical process (LPs), and a single LP is assigned to each processor. Aircraft state information is replicated across all LPs. Only the LP with the minimum next event time can execute safely. While one LP is executing safely all other LPs are precomputing their …
A Cache Design To Exploit Structural Locality, Curtis M. Winstead
A Cache Design To Exploit Structural Locality, Curtis M. Winstead
Theses and Dissertations
A design and VHDL implementation of a content-addressable memory (CAM) to exploit structural locality is the subject of this research. The concept of structural locality is that memory locations are referenced in the same order as they were previously referenced. Therefore, if memory locations that exhibit structural locality can be made available to the CPU (Center Processing Unit) through a fast data store, an increase in speed of the computer system can be realized. The CAM's purpose is to store memory references in the order they were used by the CPU and prefetch these locations to a smaller on- chip …
Parallelizing Serial Code For A Distributed Processing Environment With An Application To High Frequency Electromagnetic Scattering, Paul R. Work
Theses and Dissertations
This thesis investigates the parallelization of existing serial programs in computational electromagnetics for use in a parallel environment. Existing Algorithms for calculating the radar cross section of a object are covered, and a ray-tracing code is chosen for implementation on a parallel machine. Current parallel architectures are introduced and a suitable parallel machine is selected for the implementation of the chosen ray tracing algorithm. The standard techniques for the parallelization of serial code are discussed, including load balancing and decomposition considerations, and appropriate methods for the parallelization effort are selected. A load balancing algorithm is modified to increase the efficiency …
Formalization And Validation Of An Sadt Specification Through Executable Simulation In Vhdl, Daniel L. Eickmeier
Formalization And Validation Of An Sadt Specification Through Executable Simulation In Vhdl, Daniel L. Eickmeier
Theses and Dissertations
Formalizing an informal requirements specification, such as SADT, and executing the formal specification in a simulation environment, such as VHDL, provides a requirements analyst a means to validate the behavior of a specification early in the development life cycle. This research effort investigated and demonstrated the feasibility and benefit of transforming an SADT specification of a system into an equivalent VHDL executable simulation. Both non-time related behavior and concurrent, real-time related behavior is addressed. First, a decision table extension to SADT is created so that detailed, executable behavior can be specified. Next a mapping from SADT to VHDL is defined. …
Proportional Plus Integral Control Of Aircraft For Automated Maneuvering Formation Flight, John L. Dargan
Proportional Plus Integral Control Of Aircraft For Automated Maneuvering Formation Flight, John L. Dargan
Theses and Dissertations
In this study an automated formation control system for a lead and wing aircraft flight is developed. The proposed formation control system is capable of controlling like or dissimilar aircraft in maneuvering formation flight. Thus, two versions of the C-130 aircraft, the C-130A and the C-130B, are modelled. The C-130B has superior performance characteristics to that of the C- 130A. The wing aircraft continuously measures lead aircraft position with an ideal on-board relative position sensor, maneuvering to maintain relative position. External formation guidance is assumed to be released in a single data burst, consisting of formation geometry and nominal separation …
Application Of Nonlinear Qft To Flight Control Design For High Angle Of Attack Maneuvers With Thrust Vectoring, Steven J. Rasmussen
Application Of Nonlinear Qft To Flight Control Design For High Angle Of Attack Maneuvers With Thrust Vectoring, Steven J. Rasmussen
Theses and Dissertations
Nonlinear Quantitative Feedback Theory (QFT) is applied to the design of an flight Control system (FCS) to control maneuvers of an agile aircraft. To do this, maneuvers are chosen that are desirable during within visual range combat. Plant transfer functions are developed through the use of system identification, using the input/output time histories of the maneuvers. During the system identification process the q sub ij(o) are found directly and are constrained to be minimum phase. After identifying the plants, the cascaded multiple-input multiple-output QFT technique is used to design the FCS. During the design of the FCS, stability boundaries are …
Electrically Erasable Programmable Integrated Circuits For Replacement Of Obsolete Ttl Logic, Joseph V. Breen
Electrically Erasable Programmable Integrated Circuits For Replacement Of Obsolete Ttl Logic, Joseph V. Breen
Theses and Dissertations
Two microcircuits with electrically erasable programmable logic arrays, which use Fowler-Nordheim (F-N) tunneling for both programming and erasing, were designed to demonstrate the use of programmable logic for obsolete TTL logic replacement. Each microcircuit was fabricated in the Orbit 2-micron double-poly low noise analog CMOS process through MOSIS. Software to generate VHDL structural models from a pin list was developed and the logic of both designs was verified by simulation using the Zycad VHDL simulator. The first microcircuit included a simple programmable logic circuit and test cells that allowed measurement of the programming characteristics of the floating gate transistors. Test …
A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova
A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova
Theses and Dissertations
This thesis investigates electromagnetic scattering from resistive strips and resistive-loaded conducting strips using a rigorous UTD formulation. The UTD diffraction coefficients are based on the Wiener-Hopf technique and Jones' method. Scattering predictions are performed for constant resistive strips, constant resistive-loaded conducting strips, tapered resistive strips, and tapered resistive-loaded conducting strips. All strip geometries have a total width of 4 lambda. Predictions are compared to method of moments (MM) and measurements to determine the validity of the UTD prediction. Overall, there is good agreement. For TMz polarization the only deviations that occur with MM are near edge-on when the degree of …
Lqg Control Of A Deformable Mirror Adaptive Optics System With Time- Delayed Measurements, David J. Anderson
Lqg Control Of A Deformable Mirror Adaptive Optics System With Time- Delayed Measurements, David J. Anderson
Theses and Dissertations
This thesis proposes a linear quadratic Gaussian (LQG) control law for a ground-based deformable mirror adaptive optics system. The incoming image wavefront is distorted, primarily in phase, due to the turbulent effects of the earth's atmosphere. The adaptive optics system attempts to compensate for the distortion with a deformable mirror. A Hartman wavefront sensor measures the degree of distortion in the image wavefront. The measurements are input to a Kalman filter which estimates the system states. The state estimates are processed by a linear quadratic regulator which generates the appropriate control voltages to apply to the deformable mirror actuators. The …
Radar Scattering From Foamed Plastic Target Supports, Michael W. Chambers
Radar Scattering From Foamed Plastic Target Supports, Michael W. Chambers
Theses and Dissertations
This study investigates the scattering from foamed ranges to support all sizes of targets for radar cross section measurements. Two common foamed plastics, styrofoam and expanded bead polystyrene (EPS), are discussed. Two types of scattering are associated with foamed plastic, coherent and incoherent. The incoherent is normally the lowest, but has not been satisfactorily quantified. Coherent scattering is related to the shape of the target, and the emphasis of this study is on the coherent return. One goal was to predict the coherent RCS of an EPS column using the Uniform Theory of Diffraction (UTD). It was found that UTD …
Simulation Of Finite-Precision Effects In Digital Filters, Perry L. Choate
Simulation Of Finite-Precision Effects In Digital Filters, Perry L. Choate
Theses and Dissertations
This thesis develops and demonstrates software that models finite- precision effects in digital filters. Coefficient quantization and internally generated roundoff noise effects are simulated by rounding coefficients and multiplier output values to (B+1) bits. Outputs include magnitude and phase responses that may be plotted to show results of coefficient quantization. The output noise power due to roundoff is calculated. Three types of digital filter structures are examined. The first type is direct form I implementation for FIR and IIR structures, second is direct form II, and third is cascading the canonic direct form II second-order sections for higher order filter …
Application Of Silicon Micromachining To Thermal Dissipation Issues In Wafer Scale Integrated Circuits, Edward Cosnyka
Application Of Silicon Micromachining To Thermal Dissipation Issues In Wafer Scale Integrated Circuits, Edward Cosnyka
Theses and Dissertations
The purpose of this research effort was to investigate the feasibility of applying the silicon micromachining technique to thermal management as applied to integrated circuits and wafer scale integration techniques. Three silicon micromachined structures and an untextured reference wafer were compared as heat-dissipating surfaces. These four surfaces were realized using 3-inch diameter, single crystal silicon wafers. The following structures were micromachined in silicon wafers using wet chemical, anisotropic etching and photolithographic techniques: (1) randomly spaced and sized pyramids in (100)-oriented silicon, (2) deep vertical-wall grooves in (110)-oriented silicon, and (3) micro-fluid channels in (100)-oriented silicon. The heat- dissipating silicon wafers …
Binaural Sound Localization Using Neural Networks, Rushby C. Craig
Binaural Sound Localization Using Neural Networks, Rushby C. Craig
Theses and Dissertations
The purpose of this study was to investigate the use of Artificial Neural Networks to localize sound sources from simulated, human binaural signals. Only sound sources originating from a circle on the horizontal plane were considered. Experiments were performed to examine the ability of the networks to localize using three-different feature sets. The feature sets used were: time-samples of the signals, mena Fast Fourier Transform magnitude and cross correlation data, and auto-correlation and cross correlation data. The two different types of sound source signals considered were tones and gaussian noise. The feature set which yielded the best results in terms …
A Walsh-Domain Adaptive Filter, Larry J. Duvall
A Walsh-Domain Adaptive Filter, Larry J. Duvall
Theses and Dissertations
Two Walsh-domain dyadic convolution adaptive filters are developed using a circular convolution frequency-domain filter (FDF1) and the Fast LMS adaptive filter (FDF2): WDF1 and WDF2 respectively. General theory of time- domain adaptive filters and a theoretical analysis of the FDF1, FDF2, WDF1, and WDF2 filters are presented. WDF1 and WDF2 software implementation are shown to be error free. A time-domain filter (TDF) and a FDF2 frequency-domain filter (FDF) are implemented for comparison testing. The WDF1, WDF2, TDF, and FDF filters are tested using time-shifted sinusoidal and rectangular noisy and noiseless signals. WDF1 and WDF2 are shown to converge faster and …
Evaluation Of Scalar Value Estimation Techniques For 3d Medical Imaging, Rob W. Parrott
Evaluation Of Scalar Value Estimation Techniques For 3d Medical Imaging, Rob W. Parrott
Theses and Dissertations
Scalar value estimation in 3D medical imaging increases data resolution for enhanced renditions and corrects inaccurate surface formations. Accurate estimations are vital because clinical assessment is often aided by examination of 3D medical images. This thesis explores different estimation techniques and introduces the geostatistical estimation technique called kriging to the field of 3D imaging. Kriging theory claims to be the optimal estimator-- better than the standard deterministic methods commonly used. The techniques investigated are linear interpolation, trilinear interpolation, tricubic interpolation, and kriging. This research investigates scalar value estimation in the volume pre-processing operation of slice interpolation and in a surface …
Robotic Tactile Sensors Fabricated From A Monolithic Silicon Integrated Circuit And A Piezoelectric Polyvinylidene Fluoride Thin Film, Craig S. Dyson
Robotic Tactile Sensors Fabricated From A Monolithic Silicon Integrated Circuit And A Piezoelectric Polyvinylidene Fluoride Thin Film, Craig S. Dyson
Theses and Dissertations
The purpose of this research effort was to design, fabricate, and test a tactile sensor system consisting of an external high impedance switch circuit, an external multiplexing circuit, and a tactile sensor IC. In order to accomplish this objective, a hardware design and selection process was implemented along with a logical test methodology. An external multiplexer circuit samples all of the array elements in 50 ms. The current prototype sensor has linearity spanning loads of 0.8 g to 135 g, a load resolution of 20 g, and a maximum bandwidth of 25 Hz. Using an elementary shape recognition algorithm the …
A Rigorous Uniform Diffraction Analysis Of The Electromagnetic Scattering From Impedance Edges And Junctions, Joseph C. Fortney
A Rigorous Uniform Diffraction Analysis Of The Electromagnetic Scattering From Impedance Edges And Junctions, Joseph C. Fortney
Theses and Dissertations
This paper investigates the scattering from impedance strips and impedance-loaded conducting strips. The impedance strips are analyzed using Senior's impedance half plane formulation. Once the primary diffraction from the impedance half plane is presented, it is used to develop multiple diffraction mechanisms on an impedance strip. The scattering from impedance-loaded strips are analyzed using Maliuzhinets' impedance wedge formulation. The primary diffraction mechanism from an impedance wedge is used to develop the multiple diffractions on an impedance double wedge. The multiple diffractions on both types of strips are developed using the Extended Spectral Ray Method. Sample calculations are made for impedance …
Gabor Segmentation Of High Resolution Synthetic Aperture Radar Imagery, Michael A. Hazlett
Gabor Segmentation Of High Resolution Synthetic Aperture Radar Imagery, Michael A. Hazlett
Theses and Dissertations
This thesis investigates the use of Gabor filters and a radial basis function (RBF) network for segmentation of high resolution (1 foot by 1 foot) synthetic aperture radar (SAR) imagery. Processing involved correlation between the SAR imagery and Gabor functions. Two methods for selecting the optimal Gabor filters are presented. This research used complex Gabor functions and operated on single polarization HH complex data. Following the selection f the proper Gabor filters, correlation coefficients for each image were calculated and used as features for the RBF network. Provided are results demonstrating how Gabor processing and a RBF network provide image …
Determination Of Bistatic Radar Clutter Power From Topographic Data, Clyde R. Heddings
Determination Of Bistatic Radar Clutter Power From Topographic Data, Clyde R. Heddings
Theses and Dissertations
The purpose of this research was to develop a procedure for estimating the average bistatic radar clutter power from a topographic map using rough surface scattering theory. First, the terrain in the radar target area was divided into sub regions having homogeneous characteristics. A joint Gaussian distribution for the surface heights was fitted from the information contained in the topographic map contour lines for each homogeneous area. From these distributions, the normalized radar cross section for each terrain area was determined. The clutter power for each range cell was then determined via a modified radar range equation. The procedure was …
Kalman Filter Tracking Of A Reflective Target Using Forward Looking Infrared And Doppler Return Measurements, Theodore D. Herrera
Kalman Filter Tracking Of A Reflective Target Using Forward Looking Infrared And Doppler Return Measurements, Theodore D. Herrera
Theses and Dissertations
Plume phenomenology experiments conducted in 1990 uncovered the existence of plume speckle reflectance emanating from the exhaust of a solid- propellant rocket motor due to the presence of metallic particulates in the plume. This impeded attempts, that are dependent upon the speckle return of an actively illuminated target hardbody, to discern the plume/hardbody interface. This thesis investigates the feasibility of employing the Doppler return phenomenon in discerning the plume/hardbody interface and locating the hardbody center-of-mass. The potential of the Doppler phenomenon's utilization lies in the fact that the Doppler return frequency spectra of the plume and the hardbody respectively possess …
Control Of A Large Flexible Space Structure Using Multiple Model Adaptive Algorithms, John A. Gustafson
Control Of A Large Flexible Space Structure Using Multiple Model Adaptive Algorithms, John A. Gustafson
Theses and Dissertations
The development and performance of moving-bank multiple model adaptive estimation (MMAE) and control (MMAC) algorithms for quelling vibrations induced in the SPICE 2 space structure are analyzed in this thesis. The structure consists of a large platform and a smaller platform connected by three legs in a tripod fashion. The model supplied by Phillips Laboratory, Kirtland AFB is used to develop a truth model and multiple reduced ordered filter models. The filter models are developed from modal analysis and internally balanced techniques. Deviations of the line-of-sight vector from the center of the large platform to the center of the smaller …
Characterizing The Sensitivity, Selectivity, And Reversibility Of The Metal-Doped Phthalocyanine Thin-Films Used With The Interdigitated Gate Electrode Field-Effect Transistor (Igefet) To Detect Organophosphorous Compounds And Nitrogen Dioxide, Clayton P. Howe
Theses and Dissertations
This study investigated the sensitivity, reversibility, and selectivity of the thin film coatings used on the interdigitated gate electrode field effect transistor (IGEFET) gas microsensor. These responses were quantified based on the dc resistance changes and frequency domain responses of the microsensor. The thin-film materials included: copper phthalocyanine (CuPc), nickel phthalocyanine (NiPc), and cobalt phthalocyanine (CoPc). The challenge gases included: diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), nitrogen dioxide, ammonia, and boron trifluoride. Tests of the CuPc thin-films and nitrogen dioxide challenges established the primary set of test parameters expected to maximize the selectivity, sensitivity, and reversibility of the thin-film coatings. …