Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (3195)
- Physical Sciences and Mathematics (3070)
- Computer Sciences (1278)
- Physics (959)
- Electrical and Computer Engineering (886)
-
- Aerospace Engineering (784)
- Operations Research, Systems Engineering and Industrial Engineering (735)
- Operational Research (419)
- Business (409)
- Optics (349)
- Signal Processing (343)
- Oceanography and Atmospheric Sciences and Meteorology (283)
- Computer Engineering (243)
- Atomic, Molecular and Optical Physics (209)
- Electrical and Electronics (209)
- Environmental Sciences (194)
- Applied Mathematics (190)
- Civil and Environmental Engineering (189)
- Aviation (186)
- Statistics and Probability (183)
- Information Security (181)
- Social and Behavioral Sciences (170)
- Atmospheric Sciences (167)
- Navigation, Guidance, Control and Dynamics (167)
- Materials Science and Engineering (165)
- Plasma and Beam Physics (156)
- Operations and Supply Chain Management (149)
- Electromagnetics and Photonics (142)
- Artificial Intelligence and Robotics (137)
- Engineering Physics (125)
- Keyword
-
- #antcenter (259)
- Machine learning (95)
- #csra (72)
- Algorithms (60)
- Kalman filtering (52)
-
- Computer networks--Security measures (51)
- Image processing (50)
- Neural networks (Computer science) (50)
- Computer security (47)
- Software engineering (47)
- Decision making (45)
- Target acquisition (45)
- Global Positioning System (44)
- Optimization (41)
- Adaptive optics (40)
- Neural networks (40)
- #ctisr (38)
- Remote sensing (36)
- Computer vision (35)
- Drone aircraft (35)
- Synthetic aperture radar (34)
- #afcec (33)
- Artificial intelligence (31)
- Atmospheric turbulence (30)
- Genetic algorithms (29)
- Mathematical optimization (29)
- Flight control (28)
- Object-oriented programming (Computer science) (28)
- Wireless communication systems (28)
- Deep learning (27)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 5401 - 5430 of 5596
Full-Text Articles in Entire DC Network
Improving Stochastic Communication Network Performance: Reliability Vs. Throughput, Leonard J. Jansen
Improving Stochastic Communication Network Performance: Reliability Vs. Throughput, Leonard J. Jansen
Theses and Dissertations
This research investigated the measurement and improvement of two performance parameters, expected flow and reliability, for stochastic communication networks. There were three objectives of this research. The first was to measure the reliability of large stochastic networks. This was accomplished through an investigation into the current methodologies in the literature, with a subsequent selection and application of a factoring program developed by Page and Perry. The second objective was to develop a reliability improvement model given that a mathematical reliability expression did not exist. This was accomplished modeling a heuristic by Jain and Gopal, into a linear improvement model. Finally, …
Binary Programming Models Of Spatial Pattern Recognition: Applications In Remote Sensing Image Analysis, Thomas G. Reed
Binary Programming Models Of Spatial Pattern Recognition: Applications In Remote Sensing Image Analysis, Thomas G. Reed
Theses and Dissertations
The major purpose of this investigation was to implement subregion allocation objectives using a network model base on an existing subregion allocation binary programming model (Benabdallah and Wright (B&W), 1990), the ultimate goal being the application of subregion allocation concepts towards the spatial analysis of satellite imagery. The multi-objective aspects of subregion allocation can be accomplished via a network formulation, a formulation vastly simpler in complexity than the binary programming models previously used. Without a network programming package that could maintain integral flows, however, deriving the solution was a tiresome task for the user. Nonetheless, several new concepts and advantages …
Preliminary Design Of A Model To Assess The Effect Of Space Surveillance Network (Ssn) Sensor Upgrades On Orbit Prediction Accuracies Relative To The U. S. Anti-Satellite (Asat) Mission, Daniel L. O'Brien
Theses and Dissertations
This study gives a basis for implementation of a model to assess the effect of proposed sensor upgrades to the Space Surveillance Network (SSN) to determine if more accurate orbital element set predictions by the Space Surveillance Center (SSC) can be obtained for U.S. anti-satellite (ASAT) targeting. Handoff orbital element set predictions to nearby ASAT facilities for single, low-orbit satellite passes over a single radar sensor are considered. Model development began with simulation of the selected satellites passing over the selected sensors producing baseline truth observations based on the NORAD simplified General Publications (SGP4) model. Sensor errors, in the form …
Reducing Requirements Errors Through The Use Of Computer-Aided Software Engineering (Case) Tools And During Requirements Analysis, Marvin B. Key Jr.
Reducing Requirements Errors Through The Use Of Computer-Aided Software Engineering (Case) Tools And During Requirements Analysis, Marvin B. Key Jr.
Theses and Dissertations
This study investigated whether using CASE tools in the requirements analysis phase of software development reduced the software coding errors attributable to requirement analysis. A survey of the population gathered data as to the current practices and efforts in the use of CASE tools. The data was gathered in two groups: a control group and a sample group. The data was analyzed by group and in various combinations to obtain a greater understanding into population trends and tendencies. The results of the research indicate that the Air Force does not use CASE tools to any great extent. Also, error and …
A Formal Definition Of The Object-Oriented Paradigm For Requirements Analysis, Andrew D. Boyd
A Formal Definition Of The Object-Oriented Paradigm For Requirements Analysis, Andrew D. Boyd
Theses and Dissertations
This paper develops a formal definition of the Object-Oriented paradigm for requirements analysis. The literature was surveyed for both formal and informal methods for conducting an Object-Oriented Requirements Analysis (OORA). The informal methods reviewed are: Bailin's, Shlaer and Mellor's, Booch's, and Coad and Yourdon's. The formal methods reviewed are: Bralick's, Z, and REFINE. None of the methods were found to be adequate for doing an OORA. A formal definition of an OORA, based on the concept of classes, is developed. The definition itself is presented as set and relation theory. A supporting graphical representation is also developed and presented. The …
Documentation Requirements For Software Maintenance, Timothy S. Mcarthur
Documentation Requirements For Software Maintenance, Timothy S. Mcarthur
Theses and Dissertations
This study investigated the requirement for documentation during the maintenance phase of the software life cycle. Without proper documentation, maintenance personnel are not able to effectively understand the design of a software system and spend many hours performing design recovery before any type of maintenance can be performed. A review of existing information showed a wide range of opinion among the experts in the field of software maintenance and was not conclusive. A survey of Air Force software maintenance personnel was then conducted to determine the need, availability, and tailoring results of the documents listed on DOD-STD 2167A. The analysis …
Comparative Analysis Of Guidance Algorithms For The Hyper Velocity Missile And Afti/F-16, Edward G. Rice
Comparative Analysis Of Guidance Algorithms For The Hyper Velocity Missile And Afti/F-16, Edward G. Rice
Theses and Dissertations
This project has provided me with endless intrigue. In considering the problem of guiding a hyper-velocity missile from a moving platform to a moving target, a common perception said it was just another Kalman Filtration design challenge. I began with lofty intentions of running a full up extended Kalman filter simulation but I became enthralled with the limited work available on the physical limitations of basic guidance algorithms. This became the emphasis of this project. The best filter scheme cannot overcome a guidance algorithms physical limitation. Only with an understanding of these limitations can one effectively integrate a guidance scheme …
Gaseous Component Identification With Polymeric Film Sensor, Edward S. Kolesar Jr.
Gaseous Component Identification With Polymeric Film Sensor, Edward S. Kolesar Jr.
AFIT Patents
A sensor having an interdigitated gate electrode field effect transistor (IGEFET) coupled to an electron beam evaporated copper phthalocyanine thin film is used to selectively detect parts-per-billion concentration levels of atmosphere contaminants such as nitrogen dioxide (NO2) and diisopropyl methylphosphonate (DIMP). The sensor is excited with a voltage pulse, and its time- and frequency-domain response are examined. The envelopes of the magnitude of the normalized difference frequency spectrums reveal features which unambiguously distinguish the NO2 and DIMP exposures.
Life Cycle Costs Of The C-130 Electrical Power System Upgrade, Theodore D. Seymour
Life Cycle Costs Of The C-130 Electrical Power System Upgrade, Theodore D. Seymour
Theses and Dissertations
This research investigated the life cycle costs of three alternative electrical power systems for a planned electrical system upgrade to the C-130 transport aircraft. Research identified the contractors as (1) Sundstrand, (2) Westinghouse, and (3) Leland. The literature review included discussions on the C-130, electrical power systems and the proposed alternatives, and the elements of life cycle cost analysis. In the discussion on supportability issues, this research evaluated changes in mission capable rates and the needed fleet size to perform the current mission. In estimating Operating and Support costs, this research used the analogy approach. Analogies were based on expert …
Analysis Of The Cash Recovery Rate's Potential Application In Determining The Social Cost Of Capital, Francis J. Geiser Iii
Analysis Of The Cash Recovery Rate's Potential Application In Determining The Social Cost Of Capital, Francis J. Geiser Iii
Theses and Dissertations
This study explored the potential application of the cash recovery rate in determining the social cost of capital. It specifically investigated the results of using cash-recovery rate-based, internal rate of return-estimating relationships, which were formulated under assumptions of constant investment growth rate, to estimate internal rates of return for simulated firm-level financial data generated using both exponentially increasing and sinusoidal investment growth rates. An extensive literature review is used to build a analytical link between the need for updating the social discount rate, capital budgeting decisions based on internal rates of return, and the proposed behavior of the cash recovery …
An Investigation Of Project Management Techniques For Scheduling Raaf Depot Level Maintenance, Kerry M. Bayley
An Investigation Of Project Management Techniques For Scheduling Raaf Depot Level Maintenance, Kerry M. Bayley
Theses and Dissertations
This research investigates scheduling performances of commercial project management software. It is based on difficulties that the Royal Australian Air Force experienced in evaluating microcomputer-based packages in maintenance task scheduling of aircraft undergoing Depot Level Maintenance. A literature review found only one paper quantifying commercial software performances. No standard performance metrics or test data were found. Several packages were evaluated using a common set of 110 single-project resource- constrained networks. The performance measure used was closeness to optimally minimum Total Durations. No package performed best on all problems. On average, the best produced schedules 5.2% longer than optimal, with 95 …
Estimate-At-Completion Research - A Review And Evaluation, John W. Mckinney
Estimate-At-Completion Research - A Review And Evaluation, John W. Mckinney
Theses and Dissertations
This research derives from the Performance Measurement discipline and consists of a comprehensive analysis of Estimate-At-Completion (EAC) studies published since 1973. The EAC studies consisted of models, comparison studies, and computer analysis programs. Each study was categorized by formula type and described in terms of methodology and conclusions. Each study was evaluated based on clarity, documentation, methodology, and source. After reviewing the studies some areas were found to be weak. The AFSC formula that uses weighted percentages of .2 SPI and .8 CPI, is not supported by a critical review of the literature. In the area of comparisons studies, different …
An Analysis Of Measures Used To Evaluate The Air Force Critical Item Program, Robert R. Lee
An Analysis Of Measures Used To Evaluate The Air Force Critical Item Program, Robert R. Lee
Theses and Dissertations
The purpose of this study was to evaluate the potential of two measures, percent defects and cycle time, to measure the overall performance of the Air Force Critical Item Program (CIP). The need for such study was generated from the current absence of any measurement system available to evaluate the CIP. This research used these two measures with actual data, evaluated the correlation between aircraft availability and percent defects and cycle time, and analyzed management perceptions addressing the usefulness of these measures for field use. Performance of this analysis resulted in support for these measures by over two thirds of …
An Evaluation Of The United States Air Force Vehicle Burden-Sharing Programs, Harold E. Frary
An Evaluation Of The United States Air Force Vehicle Burden-Sharing Programs, Harold E. Frary
Theses and Dissertations
The purpose of this research was to examine the issues surrounding the U.S. Air Force vehicle burden-sharing initiative with South Korea. In doing this, the study examined additional vehicle programs with the South Korean government as well as with NATO alliances to provide an historical background and insight into the concerns that faced vehicle managers with those programs. In addition, several transportation experts throughout the Department of Defense were interviewed for their perspective of the vehicle management issues which relate to these programs. This research revealed several issues that continue to concern transportation expert. These areas include the accurate and …
Stockless Medical Materials Management: Applications For The United States Air Force Medical Service, Thomas M. Harkenrider
Stockless Medical Materials Management: Applications For The United States Air Force Medical Service, Thomas M. Harkenrider
Theses and Dissertations
The purpose of this research was to study stockless materials management in an effort to determine if it could improve the Air Force Medical Service's supply operations. The main result of this study was a decision support system (DSS) that would evaluate potential savings if stockless materials management were implemented in an Air Force medical treatment facility (MTF). In the process of developing the DSS, stockless materials management was studied in civilian hospitals that had previously converted to stockless materials management. Data included facility bed size, annual medical supply purchases, pre and post stockless medical supply full time equivalents (FTEs), …
Higher-Order Thickness Expansions For Cylindrical Shells, Randy A. Smith
Higher-Order Thickness Expansions For Cylindrical Shells, Randy A. Smith
Theses and Dissertations
Eight variations of higher-order transverse shear deformation (HTSD) theory were developed for composite shells. Three attributes were varied to produce the eight variations. These attributes include the order of the thickness expansions used to approximate the shell shape factors and the assumed linear displacement field and the nonlinearity of transverse shear strain. Several cylindrical shell problems were investigated using SHELL, a finite- element code with a 36 degree of freedom cylindrical shell element. MACSYMA, a symbolic manipulation code, was used to formulate the element independent stiffness arrays for each variation of the theory. When all nonlinear strain- displacement terms for …
A Topological Model For Parallel Algorithm Design, Jeffrey A. Simmers
A Topological Model For Parallel Algorithm Design, Jeffrey A. Simmers
Theses and Dissertations
This research demonstrates that formal, mathematical analysis in theoretical computer science can be recast in terms of the topology of complete metric spaces, and also presents a methodical technique for developing formal specifications. This effort shows that the topology of complete metric spaces provides a tool that can be used to both recreate major results about computational models and also to develop new results about these models. Using the two computational models CSP and UNITY, this effort shows that the required mathematics needed to support this alternative to the traditional analysis of computational models can be readily supported by a …
A Value-Based Hierarchy Of Objectives For Military Decision-Making, Lowell A. Nelson
A Value-Based Hierarchy Of Objectives For Military Decision-Making, Lowell A. Nelson
Theses and Dissertations
This study develops a rational model for the incorporation of ethical values into military decision-making. The values considered include obedience to superiors, professional competence, and elements of just war theory such as proportionality and discrimination. A review of the relevant literature on just war theory and professional military ethics points to the science of multi-attribute utility analysis as a means of representing the complex value tradeoffs essential to military decisions. The values and tradeoffs identified are interpreted in a hierarchy of objectives model which is used to evaluate value preferences between decision alternatives. With the hierarchy constructed, tradeoffs between values …
Investigation Of Advanced Aircraft Performance Measures Of Merit Including New Agility Metrics, Bruce A. Fox
Investigation Of Advanced Aircraft Performance Measures Of Merit Including New Agility Metrics, Bruce A. Fox
Theses and Dissertations
Advanced aircraft performance measures of merit have been proposed and individually analyzed by various researchers. These metrics have been consolidated into a single computer code as part of this research effort. This code was used to study the relationships between the advanced metrics, aircraft design metrics and an aircraft's trajectory performance. The study found a linear relationship existed between the advanced metrics and the design metrics. This relationship was used to quantify the required levels of the advanced metrics which would give desired changes in trajectory performance. The results showed that advanced metrics could be applied only to very specific …
Model Identification And Control System Design For The Lambda Unmanned Research Vehicle, Gerald A. Swift
Model Identification And Control System Design For The Lambda Unmanned Research Vehicle, Gerald A. Swift
Theses and Dissertations
Research for this thesis centered on the Lambda Unmanned Research Vehicle (URV), an asset of the Flight Dynamics Directorate, Wright Laboratory Patterson AFB. The following tasks were accomplished: (1) a linear, state-space, small perturbation model was developed for both the longitudinal and lateral directional dynamics of the vehicles, and (2) pitch rate roll rate, and yaw rate flight controllers were designed using classical and multivariable feedback methods. The parameters of the linear, state space, small perturbation model were estimated from actual flight test data. Digital Datcom was first used to estimate stability and control derivatives from the vehicle's geometry. Maximum …
A Method For The Optimal Disposition Of Surplus Air Force Motor Vehicles, Valerie A. Tredway
A Method For The Optimal Disposition Of Surplus Air Force Motor Vehicles, Valerie A. Tredway
Theses and Dissertations
This study developed a disposition method to enable major commands to increase the value of their vehicle fleets by optimally replacing less valuable fleet vehicles with more valuable surplus vehicles. The value of an optimal vehicle disposition method is especially significant in light of the decline in the U.S. Department of Defense (DoD) budget and base closures scheduled through fiscal year 1994. The Air Force currently spends approximately $240 million per year for vehicle replacement to maintain its motor vehicle fleet. It is advantageous, therefore, to consider replacing older vehicles in the fleet with newer surplus vehicles made available through …
Data Communications Possibilities For The Deployable Remote Consolidated Aerial Port Subsystem, John T. Rausch
Data Communications Possibilities For The Deployable Remote Consolidated Aerial Port Subsystem, John T. Rausch
Theses and Dissertations
This research's purpose was to determine the optimal candidate system for data communications with deployable Remote CAPS. The process also established justification for the selection. A formalized methodology based on Benjamin Ostrofsky's Design, Planning, and Development Methodology was used for the process. After a needs analysis of the problem, which is a lack of a mobile data communications system for MAC air transportation units, a feasibility study was completed which formulated the candidate systems to solve the problem. Finally, a preliminary activities phase evaluated each candidate system according to end user based criteria. The candidate system selected was the Very …
An Analysis Of Army Transportation Capability To Support The Distribution Of Liquid Propellant In Field Artillery Applications, John S. Lenart Jr.
An Analysis Of Army Transportation Capability To Support The Distribution Of Liquid Propellant In Field Artillery Applications, John S. Lenart Jr.
Theses and Dissertations
This study applied a screening technique methodology to systematically obtain organizational consensus in the establishment and ranking of Army surface transportation performance measurement criteria and system design attributes. This performance evaluation model was then used to assess the feasibility of three potential liquid propellant logistics concepts. Two sample groups of subject matter experts from the Army's Transportation and Ordnance (Munitions) Corps participated in the research. The methodology consisted of nominal-interacting group processes, repeated used of the pair comparison instrument, and use of a scoring model to rank-order the ten attributes. Research findings supported the Army's qualitative commitment to ensuring environmental …
Desert Express: An Analysis On Improved Customer Service, Thomas C. Thalheim
Desert Express: An Analysis On Improved Customer Service, Thomas C. Thalheim
Theses and Dissertations
Operation Desert Shield/Storm provided an opportunity to test the planning for U.S. forces to operate in a low intensity conflict. Both operations provided the opportunity for the logistics community to observe how the support forces provided the required supplies to the forward combat forces. In response to customers' requests, the U.S. Transportation Command created Desert Express, a daily package express flight from Charleston, SC to Saudi Arabia. The research question addresses the how and why Desert Express came about. Additional investigative questions cover the following: mission objectives, planners' and customers' expectations, system performance, and implications on the Defense Transportation System. …
A Validity Study On The Air Force Institute Of Technology Student Selection Criteria For Resident Master's Degree Programs, Daniel R. Sny
A Validity Study On The Air Force Institute Of Technology Student Selection Criteria For Resident Master's Degree Programs, Daniel R. Sny
Theses and Dissertations
The purpose of this thesis was to determine the validity of the selection procedures that AFIT (Air Force Institute of Technology) uses for admission to their resident graduate programs by discovering if the variables considered by the AFIT registrar's office can predict success at AFIT. The study was based on a collection of 4507 academic records of US military officers, foreign officers, and civilians who attended as AFIT students between 1975-1987. The academic records provided the predictor variables to include each graduate student's undergraduate GPA, standardized test scores, and demographics. Through correlation analysis, this study examined the relationships between the …
An Application Of Interactive Computer Graphics To The Study Of Inferential Statistics And The General Linear Model, Stephen D. Pearce
An Application Of Interactive Computer Graphics To The Study Of Inferential Statistics And The General Linear Model, Stephen D. Pearce
Theses and Dissertations
This research created a learning environment, known as the Pearce Projection Modeling Environment (PPME) which is used as a tool by a teacher and student. The PPME was developed in an effort to create a new approach to the study of the General Linear Model through a constructive and projective, geometric approach. While the geometric approach to the GLM was developed over the past century, it has not been used extensively because of the inherent complexities associated with visualizing vector spaces. With the PPME, visualization is accomplished effortlessly. The PPME is a computer program that allows the student to enter …
An Investigation Of The Air Force Risk Model, Thomas R. O'Hara
An Investigation Of The Air Force Risk Model, Thomas R. O'Hara
Theses and Dissertations
This study develops a dependent component cost risk model validation methodology and applies it to the Air Force Risk Model. The validation process consists of ensuring that logically consistent input parameters are acted on properly by the cost risk methodology. users of all dependent component risk models must be concerned with logically consistent input parameters. Two criteria define logical consistency. The first is the correlation matrix consistency and the second is the consistency between pairs of cost distributions. Three validation criteria are defined and used to validate a cost risk model. The first criterion is that the process must maintain …
A Model For Estimating Aircraft Recoverable Spares Annual Costs, Phillip L. Redding
A Model For Estimating Aircraft Recoverable Spares Annual Costs, Phillip L. Redding
Theses and Dissertations
This thesis covers three objectives: (1) develop a background reference document concerning recoverable spares cost estimating; (2) evaluate a representative sample of existing spares cost models; and (3) use aircraft physical and performance characteristics to develop a model for estimating annual replenishment spares cost. A condemnations cost estimating relationship (CER) was developed first and then both a CER and spreadsheet generated factors which related condemnations to replenishment spares costs were developed. For the condemnations CER, only logarithmic transformations provided statistically acceptable results, and even these models exhibited wide prediction intervals due to large amount of variability in the CER databases …
Education Necessary For Air Force Software Managers To Use The Ada Programming Language And Software Engineering Effectively, James W. Worley Jr.
Education Necessary For Air Force Software Managers To Use The Ada Programming Language And Software Engineering Effectively, James W. Worley Jr.
Theses and Dissertations
This research investigated the perceived Ada and software engineering education needs of software managers throughout the Air Force and provided recommendations to Air Staff for developing the education. Since the Department of Defense mandated all DOD agencies use the Ada programming language for software development, the education of the personnel who have to support the policy has lagged behind the implementation Ada is not a simple language to use and is only fully effective if used with sound software engineering principles. A survey was given to Air Force mid-level personnel who manage software in some capacity. Of the software personnel …
An Expert System Job Aid For Users Of The Automated Scheduling Module, Kevin A. Gore
An Expert System Job Aid For Users Of The Automated Scheduling Module, Kevin A. Gore
Theses and Dissertations
This research developed an Expert System for novice aircraft maintenance schedulers (AFSC: 392XX) with little experience using the Automated Scheduling Module (ASM). First, an in-depth literature review was completed. Next, personal interviews were conducted with an ASM expert and other 392XX personnel. Prototypes using VP-Expert and KnowledgePro shells were created. The knowledgePro shell was selected to create the ASM Job Aid, combining the knowledge of the expert and AFM 66-279. The program was verified, validated, and favorably reviewed by 392XX personnel. Recommendations include: The Air Force Logistics Management Center (AFLMC) examine the ASM Job AId and develop a Performance Support …