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Air Force Institute of Technology

Theses/Dissertations

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Articles 1951 - 1980 of 2086

Full-Text Articles in Physical Sciences and Mathematics

Vibrational Energy Transfer Within The B3Π(0+U) State Of 79Br2 Upon Collision With N2, O2, No, And Sf6, Gregory S. Williams Dec 1993

Vibrational Energy Transfer Within The B3Π(0+U) State Of 79Br2 Upon Collision With N2, O2, No, And Sf6, Gregory S. Williams

Theses and Dissertations

Vibrational transfer and electronic quenching in the lower vibrational levels of the 79Br2(B; v'≤3) were investigated using spectrally resolved, temporally resolved pulsed laser induced fluorescence techniques. Spectrally resolved emissions from collisionally populated Br2(B) vibrational levels were observed for N2, O2, NO, and SF6collision partners. The vibrational transfer was efficient in the nonpredissociative vibrational levels and is adequately described by the Montroll-Shuler model. An average fundamental vibrational transfer rate coefficient of kv(l,0)=3.4(±0.6) x 10-11 cm3/molec-sec predicts the vibrational transfer rates for the 0≤v'≤3 collisions with …

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Vulnerability Assessment Using A Fuzzy Logic Based Method, Richard W. Fleming Dec 1993

Vulnerability Assessment Using A Fuzzy Logic Based Method, Richard W. Fleming

Theses and Dissertations

This thesis demonstrates the feasibility of using qualitative analysis methods to evaluate computer security vulnerabilities. Although many risk analysis systems exist, few provide for the adequate analysis of identified vulnerabilities. While the main focus of this thesis is to evaluate computer security vulnerabilities, the methods involved have application in other areas requiring evaluation using qualitative methods. It is proposed, and demonstrated by this thesis, that the use of qualitative analysis using linguistic variables to describe the impact of computer security vulnerabilities is not only feasible, but intrinsically easier to understand and use than quantitative methods.

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Developing Realistic Cooperative Behaviors For Autonomous Agents In Air Combat Simulation, Dean P. Hipwell Dec 1993

Developing Realistic Cooperative Behaviors For Autonomous Agents In Air Combat Simulation, Dean P. Hipwell

Theses and Dissertations

This thesis investigated, developed and implemented cooperative decision-making behaviors in an air combat simulation by using a knowledge-based system. Knowledge-based systems were well suited for this task because of built- in features such as inference engines and rule-based constructs. This thesis addresses the specific problem of generating autonomous forces for inclusion in the Advanced Research Projects Agency Distributed Interactive Simulation program. Existing autonomous forces implementations lacked flexibility, realistic behaviors, real-time planning and other features. The simulation system in this thesis addresses the problem of realistic behavior by modeling pilot decision processes rather than aircraft platforms. The system is based on …

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Developing Realistic Behaviors In Adversarial Agents For Air Combat Simulation, George S. Hluck Dec 1993

Developing Realistic Behaviors In Adversarial Agents For Air Combat Simulation, George S. Hluck

Theses and Dissertations

This thesis describes an initial effort into creating a rule-based, reactive system for air combat simulation. This program uses the object-oriented extension of the expert system tool known as the C Language Integrated Production System CLIPS. This effort rose out of the need for creating and integrating semi-autonomous forces for the Distributed Interactive System DIS. This thesis describes the basic maneuvers a pilot uses in present air-to-air combat. The methodology includes the design decisions, knowledge-base development, phase architecture, and maneuver architecture development. The actual implementation of the selected architecture is described. This thesis also discusses the results of experimental runs …

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Investigation Into Formalization Of Domain-Oriented Parallel Software Development, Daniel P. King Dec 1993

Investigation Into Formalization Of Domain-Oriented Parallel Software Development, Daniel P. King

Theses and Dissertations

This research investigates the conceptual design of a semi-automated platform for parallel software development. The proposed semi-automated environment applies transformational techniques and domain-specific knowledge to a parallel software development process. Domain-specific and software design knowledge interact within the transformational development process in the creation of a software application. The underlying parallel specification language requires a set of parallel composition operators in order to capture an application’s concurrent properties. A set of parallel composition operators is proposed that consists of parallel composition, parallel enumeration, nondeterministic choice, sequential composition specific communication and synchronization variable types are also proposed. A semi-automated environment based …

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Developing A Sophisticated User Interface To Support Domain-Oriented Application Composition And Generation Systems, Jay A. Cossentine Dec 1993

Developing A Sophisticated User Interface To Support Domain-Oriented Application Composition And Generation Systems, Jay A. Cossentine

Theses and Dissertations

This research refined the visual presentation and usability of a previously developed visual interface for a domain-oriented application composition and generation system. The refined visual interface incorporated domain-specific bit-mapped graphics and sophisticated user interface design concepts to reduce user workload. User workload was reduced through object layout, window design, and color utilization techniques; by combining repetitive procedures into single commands; and reusing, rather than recreating, composition information throughout the application composition process. The Software Refinery environment, including its graphical interface tool INTERVISTA, was used to develop techniques for visualizing and manipulating objects contained in a formal object base. INTERVISTA was …

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A Parallel Computational Fluid Dynamics Unstructured Grid Generator, Deborah E. Davis Dec 1993

A Parallel Computational Fluid Dynamics Unstructured Grid Generator, Deborah E. Davis

Theses and Dissertations

This research addressed the development of a parallel computational fluid dynamics unstructured grid generator using Delaunay triangulation. The generator is applied to simple elliptical and cylindrical two-dimensional bodies. The methodologies used included Watsons point insertion algorithm, Holmes and Snyders point creation algorithm, a discretized surface definition, Andersons clustering function, and a Laplacian smoother. The first version of the software involved a processor boundary exchange at the end of each iteration with no inter-processor communications during the iterations The second version used inter-processor communication during each iteration instead of the boundary exchange. Version 1 demonstrated a speedup of 1.8 for some …

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A Distributed Interactive Simulation Based Remote Debriefing Tool For Red Flag Missions, Michael T. Gardner Dec 1993

A Distributed Interactive Simulation Based Remote Debriefing Tool For Red Flag Missions, Michael T. Gardner

Theses and Dissertations

Air Force leaders, recognizing the need for improved training following the Vietnam War, implemented the Red Flag exercises at Nellis AFB. At the heart of this training is the Red Flag Measurement and Debriefing System RFMDS and its capability to accurately reconstruct the elements of an intense exercise fought over the deserts of Nevada. This thesis uses the technology of distributed interactive simulation DIS to transmit aircraft telemetry onto computer networks, allowing the monitoring and analysis of live Red Flag missions at any site with compatible communications equipment and thesis software. The use of standard DIS protocols enables simulators to …

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Alternative Architectures For Domain-Oriented Application Composition And Generation Systems, Warren E. Gool Dec 1993

Alternative Architectures For Domain-Oriented Application Composition And Generation Systems, Warren E. Gool

Theses and Dissertations

This thesis presents a formalized framework for comparing the structure and semantics of software architectures. The framework uses object diagrams for analyzing the structure of the architectures and the axiomatic approach for analyzing the semantics. This framework is used to compare the Object Connection Update OCU model developed by the Software Engineering Institute against four other software architectures VHDL defined by Lipsett, MetaH defined by Honeywell, microRapide defined by Luckham, and hierarchical software systems as defined by Batory. The goal of the comparison was to evaluate the OCU model for suitability within prototype application composition and generation systems. This research …

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Performance Measurement Of Three Commercial Object-Oriented Database Management Systems, Timothy J. Halloran Dec 1993

Performance Measurement Of Three Commercial Object-Oriented Database Management Systems, Timothy J. Halloran

Theses and Dissertations

The goal of this thesis was to study the performance of three commercial object-oriented database management systems. The commercial systems studied included Itasca, sold by Itasca Systems Incorporated Matisse, sold by Intellitic International and ObjectStore, sold by Object Design Incorporated. To examine performance of these database management systems two benchmarks were run the OO1 benchmark and a new AFIT Simulation benchmark. The OO1 benchmark was designed, implemented, and run on all three database management systems. ObjectStore was our top performer on all configurations of the OO1 benchmark. The AFIT Simulation benchmark was designed, implemented, and run on the ObjectStore database …

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Integration And Enhancement Of The Saber Wargame, Karl S. Mathias Dec 1993

Integration And Enhancement Of The Saber Wargame, Karl S. Mathias

Theses and Dissertations

The Saber wargame is a theater-level air/land battle wargame written in Ada that is being developed for the Air Force Wargaming Center at Maxwell AFB, AL. This thesis documents how the user interface and simulation engine were integrated. Integration was accomplished by developing a portable object-oriented database system (OODBMS) interface. The interface was implemented in Ada and tied to an OODBMS also written in Ada. Using the interface, both subsystems were able to work from a consistent database and exchange information. The user interface was enhanced by converting it from the Software Technology for Adaptable Reliable Systems Ada/X Window System …

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Developing A Graphical User Interface To Support A Real-Time Digital Signal Processing System, Jeffrey C. Miller Dec 1993

Developing A Graphical User Interface To Support A Real-Time Digital Signal Processing System, Jeffrey C. Miller

Theses and Dissertations

A graphical software user interface for a VMEbus-based real-time digital signal processing system was designed. Use, requirements were defined and the Rumbaugh object-oriented analysis and design technique was applied to analyze the requirements and produce an object-oriented design. The software design includes a graphical, mouse- and keyboard driven user interface, specialized hardware driver modules, and operating system interfaces. An implementation plan was also developed to map the design into the C programming language using existing system code, automatically generated code, and newly written code. Based on the implementation plan, a limited software system prototype w successfully developed and demonstrated. The …

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A Prototype Architecture For An Automated Scenario Generation System For Combat Simulations, Mark W. Pfefferman Dec 1993

A Prototype Architecture For An Automated Scenario Generation System For Combat Simulations, Mark W. Pfefferman

Theses and Dissertations

This research effort examines the problem of automating the scenario generation process and presents a prototype architecture for an automated scenario generation system. This architecture is designed using an object- oriented approach which leads to a modular and modifiable design. The architecture provides a mechanism for automatically generating scenario files from a textual US Army operation order. This translation process occurs in two phases. First, the text operation order is translated into an intermediate format called the mission file. In the second phase, the system reads the mission file, instantiates intelligent entities, and assigns missions to those entities. The intelligent …

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Design Of A Shared Coherent Cache For A Multiple Channel Architecture, John A. Reisner Dec 1993

Design Of A Shared Coherent Cache For A Multiple Channel Architecture, John A. Reisner

Theses and Dissertations

The Multiple Channel Architecture MCA is a recently proposed computer architecture which uses fiber optic communications to overcome many of the problems associated with interconnection networks. There exists a detailed MCA simulator which faithfully simulates an MCA system, however, the original version of the simulator did not cache shared data. In order to improve the performance of the MCA, a cache coherency protocol was developed and implemented in the simulator. The protocol has two features which are significant: (1) a time-division multiplexed TDM communication bus is used for coherency traffic, and (2) the shared data is cached in an independent …

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Object Interaction In A Parallel Object-Oriented Discrete-Event Simulation, Walter G. Trachsel Dec 1993

Object Interaction In A Parallel Object-Oriented Discrete-Event Simulation, Walter G. Trachsel

Theses and Dissertations

This thesis investigates object interaction issues involved in developing an object-oriented parallel discrete-event simulation and develops a simulation model that provides object interaction capabilities. The research covers issues in object representation, object interaction, object management. discrete-event simulation, and parallel simulation. There are three primary types of objects that the research discusses. The first type is a basic simulation object, whose size and behavior is insignificant compared to the size of the simulation as a whole. The second type is an aggregate object which consists of smaller component objects that interact and affect the performance of the larger object as a …

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Domain Modeling Of Time-Dependent Systems, Robert W. Waggoner Dec 1993

Domain Modeling Of Time-Dependent Systems, Robert W. Waggoner

Theses and Dissertations

This research investigated the feasibility of composing time-dependent specifications in Architect, a domain-oriented application composition and generation system being developed at the Air Force Institute of Technology (AFIT). Architect composes formally specified domain objects into an executable software specification that can be used to verify program correctness prior to generation of language specific code. As part of this research, domain modeling techniques were investigated and a candidate process was selected for evaluation. The process was used to develop domain models for two diverse time-dependent domains. Using object-oriented analysis, formal specifications were developed for a collection of event-driven logic circuit components …

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A Method For Populating The Knowledge Base Of Afit's Domain-Oriented Application Composition System, Russell M. Warner Dec 1993

A Method For Populating The Knowledge Base Of Afit's Domain-Oriented Application Composition System, Russell M. Warner

Theses and Dissertations

This research developed a formal method for adding new domains to Architect, a domain-oriented application composition system being developed at the Air Force Institute of Technology AFIT to explore new software engineering technologies. 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 is implemented in the Software Refinery environment, which allows Architect to create and manipulate object-oriented specifications. As a part of this research effort, domain-oriented application composition systems were …

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Three Dimensional Object Recognition Using A Complex Autoregressive Model, David E. Chelen Dec 1993

Three Dimensional Object Recognition Using A Complex Autoregressive Model, David E. Chelen

Theses and Dissertations

Based on an autoregressive model, Complex Partial Correlation CPARCOR features are known to provide exceptional Position, Scale, and Rotation Invariant PSRI properties for planar 2-Dimensional 2-D object recognition. Although autogressive models have been successfully applied to numerous spatio-temporal recognition tasks, the effects of out-of-plane image rotations were never considered. This study investigates application of the CPAR-COR model to a five class problem of nonplanar 2-D views of 3-D objects. Recognition based on CPAR-COR features is evaluated using a Template Matching algorithm, two K-Nearest-Neighbor KNN classifiers, and a Hidden Markov Model HMM. Direct comparisons to recognition based on Fourier features are …

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Identity Verification Through The Fusion Of Face And Speaker Recognition, John G. Keller Dec 1993

Identity Verification Through The Fusion Of Face And Speaker Recognition, John G. Keller

Theses and Dissertations

In this research, face recognition and speaker identification systems are each converted into verification systems. The two verification systems are then fused to form a single identity verification system. Finally, the use of the Karhunen-Loeve Transform (KLT) for dimensional reduction is examined for suitability in the verification task. The base face recognition system used the KLT for feature reduction and a back-propagation neural net for classification. Verification involved training a net for each individual in the database for two classes of outputs, 'Joe' or 'not Joe.' The base speaker identification system used Cepstral analysis for feature extraction and a distortion …

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Investigation Into Model-Based Fuzzy Logic Control, Michael W. Logan Dec 1993

Investigation Into Model-Based Fuzzy Logic Control, Michael W. Logan

Theses and Dissertations

This thesis investigates the feasibility of a proposed hybrid linear/Fuzzy controller for nonlinear plants. The proposed controller concept is based on the use of multiple linearizations of a nonlinear plant, which describe the dynamics of perturbations about equilibrium points throughout the desired envelope of operation. A bank of linear compensators is developed, each corresponding to a linearized plant about a different equilibrium. The multiple control signals generated by the bank of compensators are then weighted and summed using Fuzzy Logic to produce a composite control perturbation signal, which is used to drive the nonlinear plant. Experiments were conducted to test …

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Failure Detection, Isolation, And Recovery In An Integrated Navigation System, William B. Mosle Iii Dec 1993

Failure Detection, Isolation, And Recovery In An Integrated Navigation System, William B. Mosle Iii

Theses and Dissertations

An Inertial Navigation System (INS), the Global Positioning System (GPS), and a ground based transponder system (RRS) can all be used to provide the user with a navigation solution. Yet by integrating these three navigation systems with an extended Kalman filter (EKF), a navigation solution is attained that benefits from the information of all three subsystems. This research develops a multiple model EKF failure detection, isolation, and recovery (FDIR) algorithm using a Chi-Square failure test to provide robust navigation solution to measurement failures. The algorithm specifically counters failures in the GPS and RRS range measurements. Analysis is conducted using a …

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Performance Comparison Of Shearing Interferometer And Hartmann Wave Front Sensors, Timothy L. Pennington Dec 1993

Performance Comparison Of Shearing Interferometer And Hartmann Wave Front Sensors, Timothy L. Pennington

Theses and Dissertations

The resolution of optical imaging systems is severely degraded from the diffraction limit by the random effects of the atmosphere. Techniques exist to compensate for the atmospheric turbulence, one of which is adaptive optics. A critical component in the adaptive optics system is the wavefront sensor. Presently, two types of sensors are being used-the Hartmann-Shack Wavefront Sensor and the Shearing Interferometer. Previous studies have compared these two sensors and found them to perform identically for a point source. However, to date, no comparison has been performed for an extended source and subaperture spacing larger than the correlation length of the …

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Characterization Of Nonlinear Effects In Optically Pumped Vertical Cavity Surface Emitting Lasers, Scott L. Brown Dec 1993

Characterization Of Nonlinear Effects In Optically Pumped Vertical Cavity Surface Emitting Lasers, Scott L. Brown

Theses and Dissertations

The nonlinear characteristics of optically pumped Vertical Cavity Surface Emitting Lasers VCSELs are identified, isolated, and quantified. Three different VCSELs are evaluated including two with gain regions of bulk GaAs operating at 875nm and one multi-quantum well MQW InGaAs VCSEL operating at 950nm. The nonlinearities evaluated include those due to cavity temperature, carrier injection, and internal lasing field. The VCSELs are pumped by a picosecondfemtosecond TiSapphire laser which is configured to operate in CW, gated CW minimum gate width was 200ns, picosecond, and gated picosecond modes. A linear relationship is shown between wavelength and substrate temperature, cavity temperature, and injected …

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Optical Wavelet Transform For Fingerprint Identification, Robert P. Macdonald Dec 1993

Optical Wavelet Transform For Fingerprint Identification, Robert P. Macdonald

Theses and Dissertations

The Federal Bureau of Investigation FBI has recently sanctioned a wavelet fingerprint image compression algorithm developed for reducing storage requirements of digitized fingerprints. This research implements an optical wavelet transform of a fingerprint image, as the first step in an optical fingerprint identification process. Wavelet filters are created from computer generated holograms of biorthogonal wavelets, the same wavelets implemented in the FBI algorithm. Using a detour phase holographic technique, a complex binary filter mask is created with both symmetry and linear phase. The wavelet transform is implemented with continuous shift using an optical correlation between binarized fingerprints written on a …

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A Theoretical Investigation Of Electrically Tunable Birefringent Optical Filters As The Special Discriminator In Hyperspectral Imaging Systems, Duane A. Sauve Dec 1993

A Theoretical Investigation Of Electrically Tunable Birefringent Optical Filters As The Special Discriminator In Hyperspectral Imaging Systems, Duane A. Sauve

Theses and Dissertations

This study investigated electrically tunable birefringent optical filters for use as the spectral discriminator in hyperspectral imaging systems. Spectral discrimination requirements for hyperspectral systems were defined using specification from two state-of-the-art hyperspectral imaging systems. The spectral discrimination requirements led to the definition of the ideal tunable optical filter for spectral discrimination purposes. Analytical and computer an analysis was performed for known birefringent filters which showed promise of electrical tunability excluding acousto-optic filters. No perfect match was found to the ideal tunable optical filter for hyperspectral imaging defined in this thesis. Both Lyot and Solc based filters exhibited two drawbacks for …

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Development Of Computer Software To Aid Environmental Decision Makers In The Education And Training Of Air Force Remedial Project Managers, Roger R. Ouellette, Bruce K. Lyman Dec 1993

Development Of Computer Software To Aid Environmental Decision Makers In The Education And Training Of Air Force Remedial Project Managers, Roger R. Ouellette, Bruce K. Lyman

Theses and Dissertations

By the end of Fiscal Year 1991, the Air Force had identified 4,354 contaminated sites. Much like the 177 toxic sites at McClellan AFB, bases across the country and throughput the world are filled with chrome, lead, paint solvents and many other toxics that are rendering water supplies unusable and endangering the health of millions of people living in and around these bases. Air Force officials continue to identify contaminated sites with no end in sight. Since the cleanup of these toxic materials involves diverse, complex activities, the Air Force created the duty position of Remedial Project Manager to manage …

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Developing Prediction Regions For A Time Series Model For Hurricane Forecasting, William Cheman Dec 1993

Developing Prediction Regions For A Time Series Model For Hurricane Forecasting, William Cheman

Theses and Dissertations

In this thesis, a class of time series models for forecasting a hurricanes future position based on its previous positions and a generalized model of hurricane motion are examined and extended. Results of a literature review suggest that meteorological models continue to increase in complexity while few statistical approaches, such as linear regression, have been successfully applied. An exception is provided by a certain class of time series models that appear to forecast storms almost as well as current meteorological models without their tremendous complexity. A suggestion for enhancing the performance of these time series models is pursued through an …

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Performance Impacts For Actuator Misalignments And Failures In Large- Aperture Adaptive-Optic Telescopes, Timothy D. Hogan Dec 1993

Performance Impacts For Actuator Misalignments And Failures In Large- Aperture Adaptive-Optic Telescopes, Timothy D. Hogan

Theses and Dissertations

Large-aperture telescopes require adaptive optics in order to compensate for atmospheric turbulence which would otherwise negate the resolution advantages of using large apertures. This investigation analyzes the impacts of misalignments and failures, in the deformable mirror actuators, upon the performance of such systems. A numerical simulation of a standard adaptive optics system is used to generate characteristic optical transfer function OTF and signal-to-noise ratio SNR performance metrics. The performance impacts of the misalignments are shown to be dependent upon the Fried parameter effective telescope diameter, the source object brightness, and the control system time delay. The degree of performance degradation …

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System Design Analysis Of A Lightweight Laser Satellite Terminal, Brian C. Page Dec 1993

System Design Analysis Of A Lightweight Laser Satellite Terminal, Brian C. Page

Theses and Dissertations

This study investigated the technological feasibility of a man- portable satellite laser communications system. Areas of interest were an end- to-end system analysis on the communications link evaluation of atmospheric effects and evaluation of semi-conductor lasers as the laser source. A literature search revealed that satellite laser communication research is primarily directed at inter-satellite links. There have been some proposed systems for space-to-ground laser communications systems, but they all utilize large fixed ground stations. The focus of this research effort is directed at a small man-portable ground station capitalizing on recent advances in semiconductor laser devices. Baseline satellite communication systems …

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Solving The Ranking And Selection Indifference-Zone Formulation For Normal Distributions Using Computer Software, Catherine A. Poston Dec 1993

Solving The Ranking And Selection Indifference-Zone Formulation For Normal Distributions Using Computer Software, Catherine A. Poston

Theses and Dissertations

Ranking and selection procedures are statistical methods used to compare and choose the best among a group of similar statistically distributed populations. The two predominant approaches to solving ranking and selection problems are Guptas subset selection formulation and Bechhofers indifference- zone formulation. For the indifference-zone formulation where the populations have equal sample sizes, Barr and Rizvi developed an integral expression of the probability of correct selection PCS. Given appropriate parameters, the integral expression can be solved to determine the common sample size required to attain a desired PCS. Tables with selected solutions to the integral expression are available for a …

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