Engineering Commons^™

Compensation Techniques In Accelerator Physics, Hisham Kamal Sayed

Physics Theses & Dissertations

Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two …

Solving The Vehicle Re-Identification Problem By Using Neural Networks, Tanweer Rashid

Computational Modeling & Simulation Engineering Theses & Dissertations

Vehicle re-identification is the process by which vehicle attributes measured at one point on a road network are compared to vehicle attributes measured at another point in an effort to match vehicles without using any unique identifiers such as license plate numbers. A match is made if the two measurements are estimated to belong to the same vehicle. Vehicle attributes can be sensor readings such as loop induction signatures, or they can also be actual vehicle characteristics such as length, weight, number of axles, etc. This research makes use of vehicle length, travel time, axle spacing and axle weights for …

Investigation And Comparison Of Proportional Navigation Guidance And Beam Rider Guidance, Ertac Olgun

Electrical & Computer Engineering Theses & Dissertations

Air defense has an increasing importance in today's wars. To gain the advantage in air combat, pursuit interceptor aircraft, which use Air-to-Air Missiles (AAMs), have become more and more significant. However, these are not sufficient alone. The importance of Surface-to-Air Missiles (SAMs) also can not be ignored in air defense.

SAMs can use different tactical navigation guidance methods. Of these, two of the more important guidance methods are Proportional Navigation Guidance and Beam Rider Guidance, which are investigated in this thesis. To understand the idea better, a brief description and discussion of missiles are provided. Parts of the guided missiles …

Long Term Surface Power Generator Design For Mars: Autonomously Deployable Photovoltaic Solar Arrays Along With Regenerative Fuel Cell Modules, Omer Demirok

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis studies the feasibility of incorporating a large autonomously deployed photovoltaic solar array power system as the primary power source for a large fixed Mars base. A mission duration of 10 Earth years has been assumed and the nominal power demands have been specified as a minimum of 40 kW, during daytime operation and a continuous 10 kW. demand for nighttime operation.

The overall system design developed in this thesis has an estimated total mass of 7,400 kg, when utilizing hydrogenated amorphous silicon thin film solar arrays and an estimated total mass of 5,100 kg when utilizing polycrystalline copper-indium-diselenide …

Modeling The Contagion Effect Of Foreclosures Within The Real Estate Market By Use Of Agent-Based Modeling And Simulation, Marshall William Gangel

Computational Modeling & Simulation Engineering Theses & Dissertations

Over the last several years, the US financial and real estate markets have experienced a significant recession. During this downturn, the number of real estate foreclosures rose drastically. Recent studies have empirically demonstrated a reduction in real estate values due to foreclosures. The observed reduction in the average value of real estate properties has been labeled the foreclosure contagion effect. The foreclosure contagion effect impacts healthy neighboring properties that surround the foreclosed property as a function of time and distance.

This study uses an agent-based modeling and simulation (ABMS} approach to explore the contagion effect of foreclosures. For this research, …

A Probabilistic Analysis Of Misparking In Reservation Based Parking Garages, Vikas G. Ashok

Computer Science Theses & Dissertations

Parking in major cities is an expensive and annoying affair, the reason ascribed to the limited availability of parking space. Modern parking garages provide parking reservation facility, thereby ensuring availability to prospective customers. Misparking in such reservation based parking garages creates confusion and aggravates driver frustration. The general conception about misparking is that it tends to completely cripple the normal functioning of the system leading to chaos and confusion. A single mispark tends to have a ripple effect and therefore spawns a chain of misparks. The chain terminates when the last mispark occurs at the parking slot reserved by the …

Growth Of Alkali Antimonide Photosensitive Thin Films, George Annobil

Electrical & Computer Engineering Theses & Dissertations

The experiment performed in this research addresses the growth of an alkali antimonide photosensitive film. Research was conducted to understand and develop a growth technique for a unique vapor deposition system in a vacuum environment. Specifically, the grown film will be utilized as a photocathode, and hence quantum efficiency (QE) and photocathode lifetime measurements are conducted. The research presents the successful growth of the binary compound cesium antimonide with achieved quantum efficiency of ~0.07% at ~240V anode bias. This experimental result demonstrated that the deposition technique was reliable in producing a feasible cathode. It further allowed the verification of theoretical …

A Study Of Diversity Techniques For Lte Wireless Systems, Ferhat Kaplan

Electrical & Computer Engineering Theses & Dissertations

The demand of attaining information and the wish to communicating anytime and anywhere has caused numerous innovations in the digital communication world. Today, approximately half of the people on earth somehow use wireless technology which is in every part of our lives. LTE (Long Term Evolution) and WIMAX (Worldwide Interoperability for Microwave Access) standards are the two leading wireless technologies, which support high data rates, multimedia applications, and voice video communications at very high speeds, also called 4G cellular systems in the global market.

These high expectations from wireless technology have revealed multiple antenna techniques which improve the performance and …

Ionic Current Rectification Phenomena In Asymmetrical Polymer Nanopores Under Salt Gradients, Murat Bakirci

Mechanical & Aerospace Engineering Theses & Dissertations

The magnitude of current through a conical nanopore filled with an electrolyte solution depends on the polarity of the applied bias, indicating an asymmetric diode-like current-voltage (I-V) curve. This kind of phenomenon refers to ionic current rectification (ICR), which is of interest because many ion-channel proteins in cellular membranes are rectifying. In addition, ICR in nanopores can be used to control ion concentrations in nano- and microfluidic systems. In this study, the ICR phenomenon through a conical nanopore simultaneously subjected to an electric field and salt concentration gradient is experimentally and numerically investigated.

The experiments were conducted in an Izon's …

Data Aggregation And Dissemination In Vehicular Ad-Hoc Networks, Khaled Ibrahim

Computer Science Theses & Dissertations

Vehicular Ad-Hoc Networks (VANETs) are a fast growing technology that many governments and automobile manufacturers are investing in to provide not only safer and more secure roads, but also informational and entertainment-based applications for drivers. The applications developed for VANETs can be classified into multiple categories (safety, informational, entertainment). Most VANET applications, regardless of their category, depend on having certain vehicular data(vehicular speed, X position and Y position) available. Although these applications appear to use the same vehicular data, the characteristics of this data (i.e., amount, accuracy, and update rate) will vary based on the application category. For …

Characterizations Of Atmospheric Pressure Low Temperature Plasma Jets And Their Applications, Erdinc Karakas

Electrical & Computer Engineering Theses & Dissertations

Atmospheric pressure low temperature plasma jets (APLTPJs) driven by short pulses have recently received great attention because of their potential in biomedical and environmental applications. This potential is due to their user-friendly features, such as low temperature, low risk of arcing, operation at atmospheric pressure, easy handheld operation, and low concentration of ozone generation. Recent experimental observations indicate that an ionization wave exists and propagates along the plasma jet. The plasma jet created by this ionization wave is not a continuous medium but rather consists of a bullet-like-structure known as "Plasma Bullet". More interestingly, these plasma bullets actually have a …

Electronic Warfare By Using Unmanned Aerial Vehicles, Aydin Meric

Electrical & Computer Engineering Theses & Dissertations

Technology continues to evolve rapidly by the day. Developments in technology should be followed closely if a country wants to become more powerful. Nowadays nobody can afford to ignore the importance of Electronic Warfare and Unmanned Aerial Vehicles (UAV) in military applications. Both of them play a crucial role in military operations that they can change the course of a war.

There are different kinds of Electronic Warfare methods that can be applied according to the situations and any evolving circumstances. In the beginning Electronic Warfare was used mainly for defensive purposes, but these days Electronic Warfare is used for …

A Hybrid Lehmer Code Genetic Algorithm And Its Application On Traveling Salesman Problems, Jun Zhang

Engineering Management & Systems Engineering Theses & Dissertations

Traveling Salesman Problems (TSP) is a widely studied combinatorial optimization problem. The goal of the TSP is to find a tour which begins in a specific city, visits each of the remaining cities once and returns to the initial cities such that the objective functions are optimized, typically involving minimizing functions like total distance traveled, total time used or total cost.

Genetic algorithms were first proposed by John Holland (1975). It uses an iterative procedure to find the optimal solutions to optimization problems.

This research proposed a hybrid Lehmer code Genetic Algorithm. To compensate for the weaknesses of traditional genetic …

A Method To Improve The Sustainment Of Systems Based On Probability And Consequences, Michael Ashton Gaintner

Engineering Management & Systems Engineering Theses & Dissertations

The FROST Method is presented which improves the efficiency of long-term sustainment of hardware systems. The FROST Method makes sustainment and scheduling decisions based on the minimization of the expected value of current and future costs. This differs from current methods which tend to base decisions not on the expected value of costs, but on the expected inventory demand found through projections using data which is often inaccurate.

Distributions are used to account for randomness and inaccuracy in inputs such as failure rates and vendor-claimed dates for end of production. A Monte Carlo technique is then used to convert these …

Towards An Organizational Strategic Vitality Theory: A Study Of A Public Sector Board Of Directors, Keith L. Woodman

Engineering Management & Systems Engineering Theses & Dissertations

Boards of directors govern practically all organizations of significant size in the public and private sector. Improving the understanding of how boards function is critical because when boards fail, the results can be devastating. Little is understood about the functioning of boards of directors in the public sector, which accounts for a significant amount of the gross national product of the world's economy. The author observed a public sector board of directors for one year. Using the grounded theory research method to analyze the observations, he generated a theory of organizational strategic vitality that describes how a board of directors …

Examination Timetabling With Mathematical Programming An Application In Turkish Air Force Academy, Emrah Koksalmis

Engineering Management & Systems Engineering Theses & Dissertations

The focus of this thesis is the educational timetabling problem, which is a very challenging problem to solve especially with a high number of the departments, branches, classes, and students. Due to the large scale of educational timetabling problems and preferences of the stakeholders, it is almost impossible to form a general model that solves all of the timetabling problems in the literature. This resulted in the need to develop and employ specific models for specific institutions.

The purpose of this study is to develop a mathematical programming model that solves the examination timetabling problem in Turkish Air Force Academy …

A Study Of The Correlation Of Sub-Aqueous Beach Profile Change And The Coastal Storm Impulse (Cosi) Parameter, Kevin Bryan Conner

Civil & Environmental Engineering Theses & Dissertations

The Coastal Storm Impulse (COSI) parameter is a recently developed storm-strength parameter that was first introduced at the San Diego, California International Conference of Coastal Engineering in 2006 (ICCE) and further examined in 2008 at the ICCE in Hamburg, Germany. This new parameter used the principles of conservation of horizontal momentum to combine storm characteristics such as surge, wave dynamics, currents, and duration into a relative scale used to classify and measure storm response and impacts. The resultant classification system was intended to evaluate potential coastal erosion and the associated loss of coastal infrastructure, as well as provide a storm …

Learning Local Features Using Boosted Trees For Face Recognition, Rajkiran Gottumukkal

Electrical & Computer Engineering Theses & Dissertations

Face recognition is fundamental to a number of significant applications that include but not limited to video surveillance and content based image retrieval. Some of the challenges which make this task difficult are variations in faces due to changes in pose, illumination and deformation. This dissertation proposes a face recognition system to overcome these difficulties. We propose methods for different stages of face recognition which will make the system more robust to these variations. We propose a novel method to perform skin segmentation which is fast and able to perform well under different illumination conditions. We also propose a method …

A Structured Project-Risk Management And Life Cycle Framework For Complex Systems: Ship Repair And Maintenance (Sr&M) Projects, Michael Craig Plumb

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation contributes to insights regarding the implications of using Project Risk Management (PRM) and Life Cycle Assessment (LCA) in managing projects for a complex system. The PRM approach apprehends many forms of risk both internal and external within a given project and assists the manager in determining the level of importance of each individual project phase and component to optimize project success. The life cycle approach to project management is used with short-term limitations with respect to a product's life cycle over several years. The literature discusses many tools and techniques that assist project managers in implementing optimal solutions, …

A Least Squares Closure Approximation For Liquid Crystalline Polymers, Traci Ann Sievenpiper

Mathematics & Statistics Theses & Dissertations

An introduction to existing closure schemes for the Doi-Hess kinetic theory of liquid crystalline polymers is provided. A new closure scheme is devised based on a least squares fit of a linear combination of the Doi, Tsuji-Rey, Hinch-Leal I, and Hinch-Leal II closure schemes. The orientation tensor and rate-of-strain tensor are fit separately using data generated from the kinetic solution of the Smoluchowski equation. The known behavior of the kinetic solution and existing closure schemes at equilibrium is compared with that of the new closure scheme. The performance of the proposed closure scheme in simple shear flow for a variety …

Batio3–Srtio3 Layered Dielectrics For Energy Storage, Sheng Chao, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

BaTiO₃–SrTiO₃ (BST) thick films (~ 250–390 μm) with layered structures were fabricated by tape-casting and lamination process. Layered composites with various Ba/Sr ratios were obtained by lamination of BaTiO₃ (BT) and SrTiO₃ (ST) tapes in different spatial configurations (2–2). As-prepared BST ceramics showed much improved sinterability over the laminates of pure BT or pure ST tapes. Dielectric properties of materials were measured in the temperature range of 25 °C to 200 °C. The method of utilizing of layered structures offered flexibility to maximize the energy storage capability at specific operating conditions: (temperature and electric field) …

Fm Demodulators In Software-Defined Radio Using Fpgas With Rapid Prototyping, Marc Anthony Padilla

Theses and Dissertations

With the advent of software-defined radio, many radio applications have and are currently being designed for FPGAs, due to their high performance and reconfigurability. Invariably, "legacy" waveforms, such as FM, will need to be supported in such systems. A challenge that comes with programming FPGAs is the increased design and implementation time over conventional software programming. In this thesis, three FM demodulator techniques are implemented and compared in an FPGA. Two techniques are found to have similar SNR performance while having very different FPGA implementation characteristics. Library based design is explored for demodulators to increase FPGA design productivity. A block …

Distributed Negf Algorithms For The Simulation Of Nanoelectronic Devices With Scattering, Stephen Cauley, Mathieu Luisier, Venkataramanan Balakrishnan, Gerhard Klimeck, Cheng-Kok Koh

Birck and NCN Publications

Through the Non-Equilibrium Green’s Function (NEGF) formalism, quantum- scale device simulation can be performed with the inclusion of electron-phonon scattering. However, the simulation of realistically sized devices under the NEGF formalism typically requires prohibitive amounts of memory and computation time. Two of the most demanding computational problems for NEGF simulation involve mathematical operations with structured matrices called semiseparable matrices. In this work, we present parallel approaches for these computational problems which allow for efficient distribution of both memory and computation based upon the underlying device structure. This is critical when simulating realistically sized devices due to the aforementioned computational burdens. …

Dynamics Of Hyporheic Flow And Heat Transport Across A Bed-To-Bank Continuum In A Large Regulated River, Katelyn E. Gerecht, M. Bayani Cardenas, Andrew J. Guswa, Audrey H. Sawyer, John D. Nowinski, Travis E. Swanson

Engineering: Faculty Publications

The lower Colorado River (LCR) near Austin, Texas is heavily regulated for hydropower generation. Daily water releases from a dam located 23 km upstream of our study site in the LCR caused the stage to fluctuate by more than 1.5 m about a mean depth of 1.3 m. As a result, the river switches from gaining to losing over a dam storage-release cycle, driving exchange between river water and groundwater. We assessed the hydrologic impacts of this by simultaneous temperature and head monitoring across a bed-to-bank transect. River-groundwater exchange flux is largest close to the bank and decreases away from …

Propeller: A Scalable Metadata Organization For A Versatile Searchable File System, Lei Xu, Hong Jiang, Xue Liu, Lei Tian, Yu Hua, Jian Hu

School of Computing: Technical Reports

The exponentially increasing amount of data in file systems has made it increasingly important for users, administrators and applications to be able to fast retrieve files using file-search services, instead of replying on the standard file system API to traverse the hierarchical namespaces.  The quality of the file-search services  is significantly affected by the file-indexing overhead, the file-search performance and the accuracy of search results.  Unfortunately, the existing file-search solutions either are so poorly scalable that their performance degrades unacceptably when the systems scale up, or incur so much crawling delays that they produce acceptably inaccurate results.  We believe that …

Nextgen Technology: From Metaphysical Perfection To Complete Failure, Anne E. Burnett

Continuing Legal Education Presentations

In this paper, I explore technologies currently available on the web which can improve the efficiency of your practice. I also point to new trends in innovation along with examples of the products coming out of those trends and recommend resources for keeping up-to-date with new gadgets and applications.

They Passed That? He Decided What? Tools And Techniques For Staying Informed About The Law, Jason Tubninis

Continuing Legal Education Presentations

Thanks to the wide-scale adoption of the Internet as a primary means of disseminating information, the amount available is increasing at an exponential rate every day. This is especially true for the legal field and the practice of law. There is an incredible amount of information being released from a myriad of sources; government agencies, legal scholars, private practitioners, experts and more are distributing a veritable treasure trove of resources online.

The question is no longer “Is it out there?” but “How can I find it?” Unfortunately, this question is becoming increasingly difficult as the shear amount being released begins …

Internet Ethics: Complications Of The Digital Age And Web Sites To Help You Untangle Them, Maureen Cahill

Continuing Legal Education Presentations

Computers and the Internet have profoundly changed at least the mechanics of the practice of law. Client communication, legal research, document drafting and transmittal, and record storage are increasingly paper free undertakings. As someone who began the practice of law long before the advent of the personal computer or the Internet, I can attest that the shift to computers and the Internet has greatly increased efficiency, productivity and convenience. At the same time, these tools can greatly complicate many traditional ethical considerations.

The paper is divided into two parts. In the first portion of this paper, I will try to …

Detecting Cracked Rotors Using Auxiliary Harmonic Excitation, Jerzy T. Sawicki, Michael I. Friswell, Zbigniew Kulesza, Adam C. Wroblewski, John D. Lekki

Mechanical Engineering Faculty Publications

Cracked rotors are not only important from a practical and economic viewpoint, they also exhibit interesting dynamics. This paper investigates the modelling and analysis of machines with breathing cracks, which open and close due to the self-weight of the rotor, producing a parametric excitation. After reviewing the modelling of cracked rotors, the paper analyses the use of auxiliary excitation of the shaft, often implemented using active magnetic bearings to detect cracks. Applying a sinusoidal excitation generates response frequencies that are combinations of the rotor spin speed and excitation frequency. Previously this system was analysed using multiple scales analysis; this paper …

Characterization And Genetic Analysis Of The Cellulolytic Microorganism Thermobifida Fusca, Yu Deng

Theses and Dissertations

Currently, one of the hurdles hindering efficient production of cellulosic biofuel is the recalcitrant nature of cellulose to hydrolysis. A wide variety of cellulase enzymes are found natively in microorganisms that can potentially be used to effectively hydrolyze cellulose to fermentable sugars. Thermobifida fusca is a high G-C content, thermophilic, gram-positive soil actinobacterium with high cellulolytic activity. The phenomenological and mechanistic parameters affecting cellulase activity were studied in T. fusca and two mechanisms have been found: 1) transcriptions of cellulase-related genes were not closely associated with measured differences in cellulase activity and 2) cellular energetics (intracellular ATP) correlated more closely …