Engineering Commons^™

Special Nuclear Material Imaging Using A High Purity Germanium Double Sided Strip Detector, Clifford V. Sulham

Theses and Dissertations

The purpose of this research is to investigate the feasibility of using a High Purity Germanium Double Sided Strip Detector (HPGeDSSD) to image Special Nuclear Material (SNM) for use in the field of nuclear nonproliferation. SNM shape can be determined by using a gamma ray imaging system that is capable of imaging either Pu-239 or U-235. The detector used for this research is a liquid-nitrogen cooled germanium detector with five charge collection strips on both faces. The strips on the two faces are orthogonal to each other, creating a five by five array of data collection pixels. When the detector …

Irrigation District Observations On Large Diameter, Low Pressure Pipeline Materials, Charles M. Burt

BioResource and Agricultural Engineering

There are approximately 1,400 miles of low pressure non-reinforced cast-in-place ("monolithic" or "CIP") concrete pipe in California irrigation districts. Cast-in-place pipe was irrigation districts’ material of choice for large diameter pipelines from 1930 to at least 1980. Many of these pipelines were installed in the early 1900’s. They are predominately found on the east side of the San Joaquin Valley, from Manteca in the north to Visalia in the south. Most of these pipes are deteriorating and will need to be replaced within the next 10-20 years.

Irrigation districts have attempted to find new ways to repair these pipes. However, …

Standards For Clean Air Florida Homes, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

These standards are designed for new, slab on grade homes built in Florida. Changes to the standards may be necessary for other house construction types. These standards are not meant to be exclusionary. The home builder may submit alternative materials or design details which will result in equivalent performance. These standards complement all building codes and do not supersede any codes.

Method Of Non-Data-Aided Carrier Recovery With Modulation Identification, Kenta Umebayashi, Robert H. Morelos-Zaragoza, Ryuji Kohno

Faculty Publications

A non-data aided carrier recovery technique using digital modulation format identification called multi-mode PLL (Phase Locked Loop) is proposed. This technique can be interpreted as a modulation identification method that is robust against static phase and frequency offsets. The performance of the proposed technique is studied and the analytical expressions are derived for the probability of lock detection, acquisition time over AWGN channel in the cases of M-PSK and M-QAM modulations with respect to frequency offset and signal-to-noise ratio.

Ultrasonic Testing For Geomembranes, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.

Ground Vibration Associated With Pipe Bursting, Alan Atalah, Paul Hadala, Ray Sterling

Construction Management Faculty Publications

Pipe bursting is a trenchless pipe replacement technique that offers advantages of low cost, reduced surface disturbance, and the ability to replace an old pipe with a new pipe of equal or larger diameter and capacity. Concerns about the use of the method have centered principally on the ground movements and vibrations produced by the technique - particularly when existing pipe is being replaced by a larger diameter pipe- and also on any damage experienced by the replacement pipe as it is being pulled into the ground. These concerns motivated the Trenchless Technology Center (TTC) to conduct a research project …

Preliminary Report On The 22 December 2003, M 6.5 San Simeon, California Earthquake, Jeanne L. Hardebeck, John Boatwright, Douglas Dreger, Rakesh K. Goel, Vladimir Graizer, Kenneth Hudnut, Chen Ji, Lucile Jones, John Langbein, Jian Lin, Evelyn Roeloffs, Robert Simpson, Keith Stark, Ross Stein, John C. Tinsley

Civil and Environmental Engineering

The M_w 6.5 San Simeon earthquake struck the central California coast on 22 December 2003 at 19:15:56 UTC (11:15:56 am local time.) The epicenter was located 11 km northeast of the town of San Simeon, and 39 km west-northwest of Paso Robles (Figure 1), as reported by the California Integrated Seismic Network (CISN, the California region of the Advanced National Seismic System [ANSS]). The mainshock nucleated at 35.702°N, 121.108°W and a depth of 7.1 km, and the rupture propagated unilaterally to the southeast. The strong directivity of the rupture resulted in a concentration of damage and aftershock...

Flight Physician - March, 2004, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A sixteen page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Corollaries On The Fixpoint Completion: Studying The Stable Semantics By Means Of The Clark Completion, Pascal Hitzler

Computer Science and Engineering Faculty Publications

The fixpoint completion fix (P) of a normal logic program P is a program transformation such that the stable models of P are exactly the models of the Clark completion of fix (P). This is well-known and was studied by Dung and Kanchanasut [15]. The correspondence, however, goes much further: The Gelfond-Lifschitz operator of P coincides with the immediate consequence operator of fix (P), as shown by Wendt [51], and even carries over to standard operators used for characterizing the well-founded and the Kripke-Kleene semantics. We will apply this knowledge to the study of …

A Differentiated Services Architecture For Quality Of Service Provisioning In Wireless Local Area Networks, Tristan Raimondi

Masters

Currently the issue of Quality of Service (QoS) is a major problem in IP networks due to the growth in multimedia traffic (e.g. voice and video applications) and therefore many mechanisms like IntServ, DiffServ, etc. have been proposed. Since the IEEE 802.11b (or Wi-Fi) standard was approved in 1999, it has gained in popularity to become the leading Wireless Local Area Network (WLAN) technology with millions of such networks deployed worldwide. Wireless networks have a limited capacity (11 Mbits/s in the case of Wi-Fi networks) owing to the limited amount of frequency spectrum available. At any given time there may …

Acuta Enews March 2004, Vol. 33, No. 3

ACUTA Newsletters

ln This lssue

Mob Cramming Slammed Shut by Federal Authorities Randal J. Hayes, Univ of No. lowa

FCC Converts ITFS Licensing to the Universal Licensing System

From ACUTA Headquarters.................... Jeri A. Semer, CAE, ACUTA Executive Director

Board Report............................ Carmine Piscopo, Providence College, ACUTA Secretary/Treasurer

Tech Talk.............................. Kevin Tanzillo, Dux Public Relations

DC Update..................................... Whitney Johnson, Retired, Northern Michigan Univ.

Nominate for 2004-05 Board of Directors

ACUTA Member Sites to See

Dealing with Dollars and lnvaders...................... Curt Harler

Welcome New Members

Intelligent Control Schemes For A Static Compensator Connected To A Power Network, Salman Mohagheghi, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Two intelligent controllers are designed for a static compensator (STATCOM) connected to a single machine infinite bus power system (SMIB): a novel nonlinear adaptive controller using artificial neural networks based on the indirect adaptive control technique and a Takagi-Sugeno type fuzzy controller. Both schemes provide nonlinear adaptive control with better performance compared to the conventional PI controllers. Simulation results are presented to compare the performances of these controllers with that of the conventional PI controllers.

Power Quality Enhancement Using Custom Power Devices [Book Review], Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Controlling The Primary Mirror In A Space-Based Telescope Utilizing An Eigenstructure Assignment Technique, Kim Kyongsoo

Theses and Dissertations

The feasibility of using a sparse array of mirrors in a satellite system is being evaluated. This study focused on the control laws necessary for achieving the minimization of the effect of vibration which happens at the primary mirror of the satellite, by using the eigenstructure assignment technique. White Gaussian noise was assumed as the external input. AFRL has developed a 79 state model with 9 control inputs and 9 outputs, 3 sparse array mirrors, and a base. To extend the theory, a simplified model with 2 mirrors and a base which has 12 states, 4 control inputs and 8 …

Axisymmetric Optical Membrane Modeling Based On Experimental Results, Brian J. Lutz

Theses and Dissertations

The United States Air Force, Department of Defense and commercial industry have recognized the great value of near-earth space development, specifically in satellites for use in communications, ground and space surveillance and more active roles. However, resolution, or the primary optic’s diameter, has been a limitation, especially for ground surveillance. Deployable optics has been investigated to allow larger optics in space and membrane optics has received increasing attention recently. The membrane’s flexible nature requires some passive and possibly active control to reduce optical distortion caused by manufacturing, deployment, or other effects during use. Piezoelectric surface controllers are one option to …

An Investigation Relating Longitudinal Pilot-Induced Oscillation Tendency Rating To Describing Function Predictions For Rate-Limited Actuators, Joel B. Witte

Theses and Dissertations

The purpose of this study was to investigate pilot-induced oscillations (PIO) and determine a method by which PIO tendency rating could be predicted. In particular, longitudinal PIO in the presence of rate-limited actuators were singled out for examination. Sinusoidal input/triangular output describing function techniques using Nichols charts were used. A new criterion dubbed Gap Criterion was calculated for PIO sensitivity. This criterion consists of the product of pilot gain necessary to cause PIO and the normalized maximum amplitude of the commanded actuator. These results were paired with simulator and flight test PIO tendency rating data. The PIO rating scale used …

Optimization Process For Configuration Of Flexible Joined-Wing, Cody C. Rasmussen

Theses and Dissertations

This study established a weight optimized configuration design of a joined-wing sensor-craft. The joined-wing aircraft concept fulfills a proposed long-endurance surveillance mission that contains an antenna structure embedded in the wing skin. The analysis was completed utilizing structural optimization, aerodynamic analyses, and response surface methodology. A sample of 62 joined-wing configurations were weight optimized. Each optimized structure was determined through a change of skin, spar, and rib thickness in the wing box by determining trimmed maneuver and gust conditions for critical flight mission points. Since the joined-wing concept has non-linear deformation characteristics, the structural optimization used both strain and buckling …

Vibrometric Detection Of Beam Damage Due To Inclusions, Aaron J. Reifsnyder

Theses and Dissertations

The Air Force Institute of Technology, in conjunction with the Structural Health Monitoring branch of the Air Force Research Laboratory, is researching methods of determining effects of notch location and size on beam structures using modal frequency analysis. This thesis explores the ability to detect included notches of varying magnitudes and locations within the frequency domain of an isotropic cantilever beam. A series of experiments employing centerline-notched 2024 T3 and 2024 0 aluminum beams was used to determine whether natural frequency measurement in beam structures is a valid mechanism for damage detection. Each specimen was excited by a strain actuator …

Experimental And Computational Analysis Of Modes In A Partially Constrained Plate, Robert M. Vandawaker

Theses and Dissertations

The field of structural health monitoring (SHM) attempts to reduce labor and cost by allowing technicians to monitor selected properties of an aircraft's structure to detect impending failure. This research examines methods to detect damage to a thermal protection system (TPS) tile using representative 2024-T3 aluminum plates. Plates are subjected to modal analysis in single and joined conditions in an attempt to provide the capability of sensing damage to a tile on the surface of a vehicle while the sensors remain on the superstructure of the airframe. Jointly, the development of a means to model the system using finite element …

Optimization Of Heterogeneous Uav Communications Using The Multiobjective Quadratic Assignment Problem, Mark P. Kleeman

Theses and Dissertations

The Air Force has placed a high priority on developing new and innovative ways to use Unmanned Aerial Vehicles (UAVs). The Defense Advanced Research Projects Agency (DARPA) currently funds many projects that deal with the advancement of UAV research. The ultimate goal of the Air Force is to use UAVs in operations that are highly dangerous to pilots, mainly the suppression of enemy air defenses (SEAD). With this goal in mind, formation structuring of autonomous or semi-autonomous UAVs is of future importance. This particular research investigates the optimization of heterogeneous UAV multi-channel communications in formation. The problem maps to the …

Geolocation Of An Audio Source In A Multipath Environment Using Time-Of-Arrival, Jeffrey A. Boggs

Theses and Dissertations

The Air Force and the Department of Defense (DoD) are continually searching for ways to protect U.S. forces, both stateside and abroad. One continuing threat, especially in the current world environment, is gunfire from an unseen sniper. Designated areas, such as a forward deployed base or motorcade route, need to be continuously monitored for sniper fire. Once detected, these gunmen need to be located in real time. One possible method for accomplishing this task is to geolocate the audio signals generated using time-of-arrival (TOA) algorithms. These algorithms rely on direct-path measurements for accuracy. Multipath environments therefore pose a problem when …

Swarm Based Implementation Of A Virtual Distributed Database System In A Sensor Network, Wen C. Lee

Theses and Dissertations

The deployment of unmanned aerial vehicles (UAVs) in recent military operations has had success in carrying out surveillance and combat missions in sensitive areas. An area of intense research on UAVs has been on controlling a group of small-sized UAVs to carry out reconnaissance missions normally undertaken by large UAVs such as Predator or Global Hawk. A control strategy for coordinating the UAV movements of such a group of UAVs adopts the bio-inspired swarm model to produce autonomous group behavior. This research proposes establishing a distributed database system on a group of swarming UAVs, providing for data storage during a …

Swarming Reconnaissance Using Unmanned Aerial Vehicles In A Parallel Discrete Event Simulation, Joshua J. Corner

Theses and Dissertations

Current military affairs indicate that future military warfare requires safer, more accurate, and more fault-tolerant weapons systems. Unmanned Aerial Vehicles (UAV) are one answer to this military requirement. Technology in the UAV arena is moving toward smaller and more capable systems and is becoming available at a fraction of the cost. Exploiting the advances in these miniaturized flying vehicles is the aim of this research. How are the UAVs employed for the future military? The concept of operations for a micro-UAV system is adopted from nature from the appearance of flocking birds, movement of a school of fish, and swarming …

Prepositioned Trailers For Aircraft Battle Damage Support, Scott M. Murray

Theses and Dissertations

Air superiority is essential in today's wartime environment. Aircraft that are damaged and not returned to combat can have a considerable impact on the quest for dominance in the air. To maintain operational effectiveness, an organization must have the capability to quickly repair damaged aircraft. The purpose of an Aircraft Battle Damage Repair (ABDR) program is to rapidly and effectively repair damaged aircraft to fly additional operational sorties and further contribute to wartime objectives. This capability must consist of providing the necessary tools and equipment for the rapid repair of aircraft. When an ABDR team deploys in support of an …

A Demand Side Requirements Model To Forecast C-17 Mobility Aircraft Availability, Joseph R. Huscroft Jr.

Theses and Dissertations

Current aircraft forecasting methods of the Air Mobility Command (AMC) Directorate of Logistics are reliant on the experience of personnel and lead to after the fact, labor-intensive analysis. These deficiencies led AMC to the development of a Mobility Aircraft Availability Forecasting (MAAF) model. The purpose of the MAAF model is threefold: predict aircraft availability in order to provide the Tanker Airlift Control Center (TACC) with a forecast of aircraft that will be available for AMC mission requirements, provide what if capabilities that analyze the effects of tasking and policy changes, and to provide foresight into problems associated with aircraft availability …

Theoretical Models For Aircraft Availability: Classical Approach To Identification Of Trends, Seasonality, And System Constraints In The Development Of Realized Models, David B. Wall

Theses and Dissertations

This research provides forecasting models that will enable the AMC Directorate of Logistics analysis section to predict aircraft availability and provide the TACC with a monthly forecast of the number of aircraft that will be available to fulfill AMC mission requirements.

Effect Of Dimple Pattern On The Suppression Of Boundary Layer Separation On A Low Pressure Turbine Blade, John P. Casey

Theses and Dissertations

Three dimple patterns were investigated to ascertain their relative effectiveness on controlling boundary layer separation from a low-pressure turbine blade. The three cases included a single row of dimples at 65% of the axial chord with 2.22 cm spacing, a single row of dimples at 65% of the axial chord with 4.44 cm spacing, and a two-row staggered pattern with rows at 65% and 76% of the axial chord with 4.44 cm spacing. The multiple row case was such that the center of the upstream dimple set at the midpoint between two downstream dimples. The dimple spacing was measured center-on-center. …

Improving The Estimation Of Military Worth Of The Advanced Tactical Laser Through Simulation Aggregation, Michael T. Cook

Theses and Dissertations

Fielding High Energy Laser (HEL) weapon systems presents technological challenges as well as employment and financial challenges. The risk associated with the challenges mandates the development process include computer simulation models capable of predicting weapon system performance from the engineering level to assessing the military worth of employing HEL systems in combat scenarios. This research effort focuses on developing laser performance data at a higher fidelity engagement model and integrating the performance data into a mission level model. The propagation of the laser from the transmitting aperture to the target is modeled at the engagement level through the employment of …

Value-Focused Thinking In The Presence Of Weight Ambiguity: A Solution Technique Using Monte Carlo Simulation, Timothy W. Porter

Theses and Dissertations

When a Decision Maker is asked to provide his or her preferences, the response represents a snapshot in time. While their preference structure elicited at any given moment may represent their revealed preferences at that point in time, it may change over time. These changing preferences over time represent ambiguity in the decision maker's preferences. Other sources of ambiguity may exist. One weakness of many decision analysis techniques today is the inability to incorporate ambiguity into the basic decision model. The existence of the problem has been known and commented on for many years. This research addresses that problem. It …

An Investigation Of The Optimal Sensor Ensemble For Sensor Fusion, Paul P. Clemans

Theses and Dissertations

This thesis continues the research begun by Storm, Bauer and Oxley in 2003 into the fusion of classifiers. It examines the fusion of up to three correlated classifiers using three different fusion techniques. The overall objective was to determine the optimal ensemble of classifiers to maximize the expected classification accuracy. The ISOC fusion method (Haspert, 2000), the ROC Within fusion method (Oxley and Bauer, 2002) and a Probabilistic Neural Network were the three fusion techniques employed in these set of experiments. Performance of the classifiers and the fusion methods is measured via ROC curves. Two possible configurations of feature correlations …