Engineering Commons^™

Fhwa--Research & Technology Program--What's New?, Leon N. Larson

Kentucky's Annual Forum on Transportation

No abstract provided.

Moving Information Instead Of People, Lee T. Todd Jr.

Kentucky's Annual Forum on Transportation

No abstract provided.

Welcome And Remarks [1991], Charles T. Wethington Jr.

Kentucky's Annual Forum on Transportation

No abstract provided.

Kentucky Transportation Hall Of Fame [1991], Kentucky Transportation Center

Kentucky's Annual Forum on Transportation

No abstract provided.

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.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 7, Number 6, September 1991, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Acuta Enews September 1991, Vol. 20, No. 9

ACUTA Newsletters

In This Issue

0+ fraud alive and well

AOS rules don't move north

Call screening not mandated

Workshop in Atlanta

Five Ps paying off

Business Manager profile

The Cognitive Status Of Risk: A Response To Thompson, L. James Valverde

RISK: Health, Safety & Environment (1990-2002)

Discussing the role that probability theory should play in Risk analysis and management, Dr. Valverde argues that Thompson's approach puts too much emphasis on the distinction between Risk subjectivism and Risk objectivism in addressing the question, "When are Risks real?"

The Calendar - September 1991, Nova University

The Calendar

No abstract provided.

Laser Bandwidth-Induced Fluctuations In The Intensity Transmitted By A Fabry-Perot Interferometer, Gerhard Klimeck, Daniel Elliott, M. Hamilton

Birck and NCN Publications

We have measured the power spectrum of the intensity Auctuations of light transmitted by a Fabry- Perot interferometer when the input field is the real Gaussian field. The real Gaussian field is a field characterized by real, random (Gaussian) amplitude Auctuations. The bandwidth of the real Gaussian field was varied, taking on values less than that of the interferometer, as well as greater. Comparisons of the measured spectra with calculated spectra are quite satisfactory. Of special interest is a feature in the spectra centered at the laser-interferometer detuning frequency.

Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

It has recently been shown that a field-equation time-derivative approximation that is commonly used in studies of laser-oscillator dynamics is not necessary and can lead to significant errors for some lasers. A related space-derivative approximation is widely used in studies of steady-state laser amplifiers. A more rigorous amplifier formalism is developed here, and the results are exact solutions of Maxwell’s equations. The improved model predicts a spatial instability, single mirror oscillation, and other interesting field behavior.

Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

In a related study the equations governing a high-gain laser amplifier have been solved numerically without making the usual slowly-varying-amplitude derivative approximation in Maxwell’s equations, and thus the field amplitudes are not restricted to vary negligibly in a distance of one wavelength. The results reveal an instability that involves reflections and oscillatory growth of perturbations away from steady state. In the present study steady-state solutions of the field equations are obtained analytically, and transformations are described for converting the equations to alternative intensity-equation sets. These intensity equations are linearized and solved for the growth rate and oscillation period of the …

A Summary Of Highway Revenues, Expenses And Distributions: 1984 Through 1991, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This report shows the history of receipts, expenses and distributions of revenues that provide funding to all local governments for highway, road and street work.

1991 Safety Belt Usage Survey And Evaluation Of Effectiveness In Kentucky, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of the survey was to establish 1991 safety belt and child safety seat usage rates in Kentucky. Data were collected at 100 sites and combined based on vehicle miles traveled for a given type of highway, rural or urban location, and county population category. Also included in this report is an analysis of accident records evaluating the effectiveness of safety belts.

Statewide usage rates were 39 percent for drivers and front-seat passengers (over 19 years of age) and 57 percent for children under four years of age (front and rear seats). Driver usage rates had increased significantly in …

A Study Of Pilot Attitudes Regarding The Impact On Mission Effectiveness Of Using New Cockpit Automation Technologies To Replace The Navigator/Weapon System Officer/Electronic Warfare Officer, William K. Starr, Donald A. Welch

Theses and Dissertations

This study analyzed the self-reported survey responses of 404 Air Force pilots concerning their perceptions of using advanced cockpit technologies to replace the Navigator, Weapon System Officer, and Electronic Warfare Officer (Nav/WSO/EWO) and the impact of advanced cockpit technologies on combat mission effectiveness. The first objective of this study was to compare, by aircraft type, the mission effectiveness factors that are always critical and almost always critical to the success of a combat mission. The second objective was to examine, from the pilot's point of view, the Nav/WSO/EWO's contribution (NAVCRIT) to enhancing the combat mission effectiveness factors. The third objective …

Efficient Aircrew Scheduling In An Operational Test And Evaluation Organization, Charles P. Modrich

Theses and Dissertations

The original intent of this research was to locate or develop tools which would improve the efficiency of the aircrew scheduling process in the 4950 Test Wing. However, late in the research it became apparent that several factors observed by the researcher complicate the implementation of more efficient methods. Therefore, the focus of the research became the documentation of those factors. A case study methodology was used in answering the investigative questions. This was an exploratory study conducted in a field setting environment. Direct observation and the use of structural interviews with scheduling personnel were the methods of data collection. …

An Analysis Of Total Quality Management In Aeronautical Systems Division, Mark D. Caudle

Theses and Dissertations

This study investigated the major schools of thought on various aspects of quality management and quality improvement. Areas covered included definitions of waste and quality, views on the cost of quality, tools and techniques used for quality improvement, and management philosophies and frameworks for continuous improvement. In addition, this study analyzed the structure and training content of the current Total Quality Management program at Aeronautical Systems Division (ASD). Pre- and post-test surveys on employee attitudes toward organizational effective were analyzed from the Advanced Cruise Missile System Program Office (SPO), the F-15 SPO, and the ASD Deputy Chief of Staff for …

A Microcomputer Program For Estimating Production Costs Of Injection Molded Plastic Structures, Kyle F. Byard

Theses and Dissertations

The job of estimating the production costs of injection molded thermoplastic structures requires designers and analysts to produce detailed preliminary drawings and consult machinists with expertise in mold production. Interviews with injection molding experts produced a scale of part complexity and associated range of labor hours for mold production. This scale is incorporated into a cost estimating methodology which allows the analyst to estimate the cost of the structure without the aid of technicians. The resulting cost model for the injection molding process is then programmed into an interactive Pascal computer program for ease of use and documentation.

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 …

An Analysis Of Fixed Wing Tactical Airlifter Characteristics Using An Intra-Theater Airlift Computer Model, Paul Pappas

Theses and Dissertations

This study used computer simulation to identify which tactical airlifter characteristics most significantly affected tactical airlift capability in a given scenario. The Generalized Air Mobility model was used to simulate a tactical airlift system. Aircraft characteristics within the model were grouped into six variables. A 2(6) two level full factorial experimental design was used to assess the effect of changes in aircraft characteristics on the effectiveness of the tactical airlift system. Yates algorithm was used to identify significant terms based upon the results of the factorial experiment. These significant terms were used to develop a parsimonious regression model that represented …

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 …

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 …

A Guide For The Consideration Of Composite Material Impacts On Airframe Costs, Jeffrey L. Isom

Theses and Dissertations

This study provides a guide to cost analysts who must consider the impact of composite materials on airframe costs. A literature review was conducted to determine the availability of cost models which incorporate the effect of composites on cost. A number of models are available, but no individual model was found that is applicable for every situation. In order to provide a baseline upon which analysts can compare model results as well as provide guidance in selecting cost drivers, a Delphi survey was conducted. Questionnaire results indicate that composite weight (as a percentage of total weight), composite part complexity, percentage …

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 …

An Evaluation Of Logistics Support For F-16 Aircraft Owned By Foreign Countries, Paul J. Lyons

Theses and Dissertations

The purpose of this thesis was to examine the logistics support provided by the United States Air Force (USAF) for F-16 aircraft owned by foreign countries. The research drew from historical trends and personal experiences to examine the ability of the U.S. to provide logistics support for F-16 aircraft owned by U.S. allies. The study found that timely, efficient support of FMS customers possessing F-16 aircraft does not appear to be a principal concern of the USAF logistics system. Complexity of processes, untimely responses, and failure to consider customer needs are common failings on the part of the USAF.

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 Exploratory Application Of Neural Networks To The Sortie Generation Forecasting Problem, James M. Dagg

Theses and Dissertations

This exploratory study assesses the accuracy of backpropagation neural networks in predicting sortie generations, given pre-specified levels of air base resources. Single hidden layer networks and two-way interaction regression metamodels were fitted to simulated data previously generated by way of a factional design for ten factors at two levels, and subsequently tested (cross-validated) via an independent testing sample. It was determined that regression metamodels were generally superior in predicting unseen cases, while their network counterparts exhibited far better goodness-of-fit characteristics. The research consistently emphasizes that goodness-of-fit in no way necessarily implies goodness-of-prediction, in that different non-equivalent statistical measures are required …

Inaccurate Data Entry Into The Air Force Maintenance Data Collection System, Jon R. Determan

Theses and Dissertations

This research investigated the data collection environment under the Core Automated Maintenance System (CAMS), a computerized information system used in the Air Force's aircraft maintenance complexes. The research measured maintenance personnel's perception of the nature, extent, and causes of data inaccuracies occurring in the CAMS data collection environment. The nature was differentiated as being either intentional or accidental. Maintenance personnel felt that difficulty in entering information into CAMS accounted for the largest percentage of intentional errors and that insufficient training on CAMS accounted for the largest percentage of accidental errors. A comparison of this research to the results of earlier …

Analysis Of Department Of Defense Organic Depot Maintenance Capacity Management And Facility Utilization Factors, Marlies Dewoody

Theses and Dissertations

This study investigated the effects of mandated depot capacity utilization rates on throughput, inventory, and operating expense. The measures of merit analyzed were work in process inventories, leadtime, and throughput. Since the services do not use a common computer system to track/compute capacity data, a computer simulation provided the data used to meet the research objectives. The simulation modeled a serially interdependent system subject to statistical fluctuations. Variability in the system was reduced by reducing the spread around the processing time mean. Buffer inventories were placed in front of each process to protect the process from variability. Constrained systems were …

Study On In-Theater Maintenance Support For Poaf F-16, Rui J. Gomes

Theses and Dissertations

The purpose of this study was to evaluate the capacity to generate a desired level of sorties of the F-16 weapon system. This capacity depends on the maintenance concept and structure, that defines a specific level of in-theater resources available. The theater is intended to reflect Portuguese Air Force logistic operations planned for the F-16, with one operational base and a possible Centralized Intermediate Repair Facility (CIRF), not co-located. The TSAR simulation program and one USAF database was used to perform the evaluation were defined and compared. The study focused on the unscheduled maintenance tasks and repairable items, in particular …