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Electronic Theses and Dissertations

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Full-Text Articles in Engineering

Partitioning A Graph In Alliances And Its Application To Data Clustering, Khurram Hassan-Shafique Jan 2004

Partitioning A Graph In Alliances And Its Application To Data Clustering, Khurram Hassan-Shafique

Electronic Theses and Dissertations

Any reasonably large group of individuals, families, states, and parties exhibits the phenomenon of subgroup formations within the group such that the members of each group have a strong connection or bonding between each other. The reasons of the formation of these subgroups that we call alliances differ in different situations, such as, kinship and friendship (in the case of individuals), common economic interests (for both individuals and states), common political interests, and geographical proximity. This structure of alliances is not only prevalent in social networks, but it is also an important characteristic of similarity networks of natural and unnatural …


Evolutionary Optimization Of Support Vector Machines, Fred Gruber Jan 2004

Evolutionary Optimization Of Support Vector Machines, Fred Gruber

Electronic Theses and Dissertations

Support vector machines are a relatively new approach for creating classifiers that have become increasingly popular in the machine learning community. They present several advantages over other methods like neural networks in areas like training speed, convergence, complexity control of the classifier, as well as a stronger mathematical background based on optimization and statistical learning theory. This thesis deals with the problem of model selection with support vector machines, that is, the problem of finding the optimal parameters that will improve the performance of the algorithm. It is shown that genetic algorithms provide an effective way to find the optimal …


Selective Mode Excitation In Specialty Waveguides Using Micro Optical, Waleed Mohammed Jan 2004

Selective Mode Excitation In Specialty Waveguides Using Micro Optical, Waleed Mohammed

Electronic Theses and Dissertations

Although optical fibers and specialty waveguides are the base of majority of today's telecom and light delivery applications, fabrication deformation, nonlinearity and attenuation limit the bandwidth of the data being transmitted or the amount of power carried by these systems. One-way to overcome these limitations without changing the fibers design or fabrication is to engineer the input light in order to excite a certain mode or a group of modes with unique optical properties. Diffractive and micro optics are highly effective for selectively coupling light to specific modes. Using micro optics, mode selective coupling can be achieved through several matching …


Discrete Nonlinear Wave Propagation In Kerr Nonlinear Media, Joachim Meier Jan 2004

Discrete Nonlinear Wave Propagation In Kerr Nonlinear Media, Joachim Meier

Electronic Theses and Dissertations

Discrete optical systems are a subgroup of periodic structures in which the evolution of a continuous electromagnetic field can be described by a discrete model. In this model, the total field is the sum of localized, discrete modes. Weakly coupled arrays of single mode channel waveguides have been known to fall into this class of systems since the late 1960's. Nonlinear discrete optics has received a considerable amount of interest in the last few years, triggered by the experimental realization of discrete solitons in a Kerr nonlinear AlGaAs waveguide array by H. Eisenberg and coworkers in 1998. In this work …


Investigation Of Nascar Restrictor Plate Manifold Insert Using Wave Engine Simulation And Response Surface Methodology, John Mason Gross Iii Jan 2004

Investigation Of Nascar Restrictor Plate Manifold Insert Using Wave Engine Simulation And Response Surface Methodology, John Mason Gross Iii

Electronic Theses and Dissertations

With the increasing growth in computer processing power, computer based computational fluid dynamics simulations are finding increasing acceptance and use in the field of internal combustion engine development. Once fully developed, such simulations provide detailed and expedient tools for testing existing theories, as well as new ideas. While numerous studies on wave propagation and fluid flow in intakes manifolds exist, most restrict the analysis to a single intake runner and port, examining only the dynamics from the runner-to-plenum junction downstream to the valve. While such analyses provide comprehensive models for wave propagation dynamics in the runner, little is published on …


Slurry Chemistry Effects On Copper Chemical Mechanical Planarization, Ying Luo Jan 2004

Slurry Chemistry Effects On Copper Chemical Mechanical Planarization, Ying Luo

Electronic Theses and Dissertations

Chemical-mechanical Planarization (CMP) has emerged as one of the fastest-growing processes in the semiconductor manufacturing industry, and it is expected to show equally explosive growth in the future (Braun, 2001). The development of CMP has been fueled by the introduction of copper interconnects in microelectronic devices. Other novel applications of CMP include the fabrications of microelectromechanical systems (MEMS), advanced displays, three dimensional systems, and so on (Evans, 2002). CMP is expected to play a key role in the next-generation micro- and nanofabrication technologies (Singh, et al., 2002). Despite the rapid increase in CMP applications, the fundamental understanding of the CMP …


Ocr: A Statistical Model Of Multi-Engine Ocr Systems, Mercedes Terre Mcdonald Jan 2004

Ocr: A Statistical Model Of Multi-Engine Ocr Systems, Mercedes Terre Mcdonald

Electronic Theses and Dissertations

This thesis is a benchmark performed on three commercial Optical Character Recognition (OCR) engines. The purpose of this benchmark is to characterize the performance of the OCR engines with emphasis on the correlation of errors between each engine. The benchmarks are performed for the evaluation of the effect of a multi-OCR system employing a voting scheme to increase overall recognition accuracy. This is desirable since currently OCR systems are still unable to recognize characters with 100% accuracy. The existing error rates of OCR engines pose a major problem for applications where a single error can possibly effect significant outcomes, such …


Sinbad Automation Of Scientific Process: From Hidden Factor Analysis To Theory Synthesis, Olcay Kursun Jan 2004

Sinbad Automation Of Scientific Process: From Hidden Factor Analysis To Theory Synthesis, Olcay Kursun

Electronic Theses and Dissertations

Modern science is turning to progressively more complex and data-rich subjects, which challenges the existing methods of data analysis and interpretation. Consequently, there is a pressing need for development of ever more powerful methods of extracting order from complex data and for automation of all steps of the scientific process. Virtual Scientist is a set of computational procedures that automate the method of inductive inference to derive a theory from observational data dominated by nonlinear regularities. The procedures utilize SINBAD – a novel computational method of nonlinear factor analysis that is based on the principle of maximization of mutual information …


Conformal Tracking For Virtual Environments, Larry Dennis Davis Jr. Jan 2004

Conformal Tracking For Virtual Environments, Larry Dennis Davis Jr.

Electronic Theses and Dissertations

A virtual environment is a set of surroundings that appears to exist to a user through sensory stimuli provided by a computer. By virtual environment, we mean to include environments supporting the full range from VR to pure reality. A necessity for virtual environments is knowledge of the location of objects in the environment. This is referred to as the tracking problem, which points to the need for accurate and precise tracking in virtual environments. Marker-based tracking is a technique which employs fiduciary marks to determine the pose of a tracked object. A collection of markers arranged in a rigid …


Design And Hardware Implementation Of A Novel Scrambling Security Algorithm For Robust Wireless Local Area Networks, Mohit Jagetia Jan 2004

Design And Hardware Implementation Of A Novel Scrambling Security Algorithm For Robust Wireless Local Area Networks, Mohit Jagetia

Electronic Theses and Dissertations

The IEEE802.11 standard for wireless networks includes a Wired Equivalent Privacy (WEP) protocol, which is a popular wireless secure communication stream cipher protocol approach to network security used to protect link-layer communications from eavesdropping and other attacks. It allows user to communicate with the user; sharing the public key over a network. It provides authentication and encrypted communications over unsecured channels. However, WEP protocol has an inherent security flaw. It is vulnerable to the various attacks, various experiments has proved that WEP fails to achieve its security goals. This thesis entails designing, evaluating and prototyping a wireless security infrastructure that …


Non-Destructive Microstructural Evaluation Of Yttria Stabilized Zirconia, Nickel Aluminides And Thermal Barrier Coatings Using Electrochemical Impedance Spectroscopy, Srinivas Vishweswaraiah Jan 2004

Non-Destructive Microstructural Evaluation Of Yttria Stabilized Zirconia, Nickel Aluminides And Thermal Barrier Coatings Using Electrochemical Impedance Spectroscopy, Srinivas Vishweswaraiah

Electronic Theses and Dissertations

There has been an urge for increasing the efficiency in advanced gas turbine engines. To fulfill these needs the inlet gas temperatures should be increased in the gas turbine engines, thermal barrier coatings (TBCs) have gained significant applications in increasing the gas inlet temperatures. Insulating characteristics of ceramic TBCs allow the operation at up to 150~250 ˚C higher gas temperatures. Because of the severe turbine engine operating conditions that include high temperature, steep temperature gradient, thermal cycling, oxidation and hot-corrosion, TBCs can fail by spallation at the interface between the metal and ceramic. The lack of understanding in failure mechanisms …


Modifications To The Fuzzy-Artmap Algorithm For Distributed Learning In Large Data Sets, Jose R. Castro Jan 2004

Modifications To The Fuzzy-Artmap Algorithm For Distributed Learning In Large Data Sets, Jose R. Castro

Electronic Theses and Dissertations

The Fuzzy–ARTMAP (FAM) algorithm has been proven to be one of the premier neural network architectures for classification problems. FAM can learn on line and is usually faster than other neural network approaches. Nevertheless the learning time of FAM can slow down considerably when the size of the training set increases into the hundreds of thousands. In this dissertation we apply data partitioning and network partitioning to the FAM algorithm in a sequential and parallel setting to achieve better convergence time and to efficiently train with large databases (hundreds of thousands of patterns). We implement our parallelization on a Beowulf …


Evaluation Of The Potential Benefits To Traffic Operations At A Toll Plaza With Express Etc Lanes, Eric Anthony Gordin Jan 2004

Evaluation Of The Potential Benefits To Traffic Operations At A Toll Plaza With Express Etc Lanes, Eric Anthony Gordin

Electronic Theses and Dissertations

The effectiveness of modifying a conventional toll plaza for implementation of an open road tolling concept with express ETC lanes was evaluated in this thesis. Speed controlled dedicated ETC lanes were replaced with express ETC lanes at the Orlando-Orange County Expressway Authority (OOCEA) University Mainline Toll Plaza. This evaluation was accomplished by utilizing collected field data and simulated scenarios using Toll Plaza SIMulation (TPSIM) software developed by the University of Central Florida. The speed controlled dedicated ETC lanes were located within toll lanes (contained within a toll plaza canopy) with widths ranging between 10 to 14 ft. These types of …


The Proteomics Approach To Evolutionary Computation: An Analysis Of Pr, Ivan Garibay Jan 2004

The Proteomics Approach To Evolutionary Computation: An Analysis Of Pr, Ivan Garibay

Electronic Theses and Dissertations

As the complexity of our society and computational resources increases, so does the complexity of the problems that we approach using evolutionary search techniques. There are recent approaches to deal with the problem of scaling evolutionary methods to cope with highly complex difficult problems. Many of these approaches are biologically inspired and share an underlying principle: a problem representation based on basic representational building blocks that interact and self-organize into complex functions or designs. The observation from the central dogma of molecular biology that proteins are the basic building blocks of life and the recent advances in proteomics on analysis …


Gauss-Newton Based Learning For Fully Recurrent Neural Networks, Aniket Arun Vartak Jan 2004

Gauss-Newton Based Learning For Fully Recurrent Neural Networks, Aniket Arun Vartak

Electronic Theses and Dissertations

The thesis discusses a novel off-line and on-line learning approach for Fully Recurrent Neural Networks (FRNNs). The most popular algorithm for training FRNNs, the Real Time Recurrent Learning (RTRL) algorithm, employs the gradient descent technique for finding the optimum weight vectors in the recurrent neural network. Within the framework of the research presented, a new off-line and on-line variation of RTRL is presented, that is based on the Gauss-Newton method. The method itself is an approximate Newton's method tailored to the specific optimization problem, (non-linear least squares), which aims to speed up the process of FRNN training. The new approach …


High Performance Data Mining Techniques For Intrusion Detection, Muazzam Ahmed Siddiqui Jan 2004

High Performance Data Mining Techniques For Intrusion Detection, Muazzam Ahmed Siddiqui

Electronic Theses and Dissertations

The rapid growth of computers transformed the way in which information and data was stored. With this new paradigm of data access, comes the threat of this information being exposed to unauthorized and unintended users. Many systems have been developed which scrutinize the data for a deviation from the normal behavior of a user or system, or search for a known signature within the data. These systems are termed as Intrusion Detection Systems (IDS). These systems employ different techniques varying from statistical methods to machine learning algorithms. Intrusion detection systems use audit data generated by operating systems, application softwares or …


Design, Fabrication And Testing Of A Shape Memory Alloy Based Cryogenic Thermal Conduction Switch, Vinu Bala Krishnan Jan 2004

Design, Fabrication And Testing Of A Shape Memory Alloy Based Cryogenic Thermal Conduction Switch, Vinu Bala Krishnan

Electronic Theses and Dissertations

Shape memory alloys (SMAs) can recover large strains (e.g., up to 8%) by undergoing a temperature-induced phase transformation. This strain recovery can occur against large forces, resulting in their use as actuators. The SMA elements in such actuators integrate both sensory and actuation functions. This is possible because SMAs can inherently sense a change in temperature and actuate by undergoing a shape change, associated with the temperature-induced phase transformation. The objective of this work is to develop an SMA based cryogenic thermal conduction switch for operation between dewars of liquid methane and liquid oxygen in a common bulk head arrangement …


Analysis Of Time Synchronization Errors In High Data Rate Ultrawideban, Lakesha Bates Jan 2004

Analysis Of Time Synchronization Errors In High Data Rate Ultrawideban, Lakesha Bates

Electronic Theses and Dissertations

Emerging Ultra Wideband (UWB) Orthogonal Frequency Division Multiplexing (OFDM) systems hold the promise of delivering wireless data at high speeds, exceeding hundreds of megabits per second over typical distances of 10 meters or less. The purpose of this Thesis is to estimate the timing accuracies required with such systems in order to achieve Bit Error Rates (BER) of the order of magnitude of 10-12 and thereby avoid overloading the correction of irreducible errors due to misaligned timing errors to a small absolute number of bits in error in real-time relative to a data rate of hundreds of megabits per second. …


Dynamic Shared State Maintenance In Distributed Virtual Environments, Felix George Hamza-Lup Jan 2004

Dynamic Shared State Maintenance In Distributed Virtual Environments, Felix George Hamza-Lup

Electronic Theses and Dissertations

Advances in computer networks and rendering systems facilitate the creation of distributed collaborative environments in which the distribution of information at remote locations allows efficient communication. Particularly challenging are distributed interactive Virtual Environments (VE) that allow knowledge sharing through 3D information. In a distributed interactive VE the dynamic shared state represents the changing information that multiple machines must maintain about the shared virtual components. One of the challenges in such environments is maintaining a consistent view of the dynamic shared state in the presence of inevitable network latency and jitter. A consistent view of the shared scene will significantly increase …


Design And Implementation Of A Digital Controller With Dsp For Half-Br, Yangyang Wen Jan 2004

Design And Implementation Of A Digital Controller With Dsp For Half-Br, Yangyang Wen

Electronic Theses and Dissertations

DC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling. Considering half-bridge isolated DC-DC converter with a current doublers rectifier has advantages over other topologies especially in the application of low-voltage and high-current DC-DC converters, the thesis take it as an …


Data Bandwidth Reduction Techniques For Distributed Embedded Simulatio, Hubert Bahr Jan 2004

Data Bandwidth Reduction Techniques For Distributed Embedded Simulatio, Hubert Bahr

Electronic Theses and Dissertations

Maintaining coherence between the independent views of multiple participants at distributed locations is essential in an Embedded Simulation environment. Currently, the Distributed Interactive Simulation (DIS) protocol maintains coherence by broadcasting the entity state streams from each simulation station. In this dissertation, a novel alternative to DIS that replaces the transmitting sources with local sources is developed, validated, and assessed by analytical and experimental means. The proposed Concurrent Model approach reduces the communication burden to transmission of only synchronization and model-update messages. Necessary and sufficient conditions for the correctness of Concurrent Models in a discrete event simulation environment are established by …


Effects Of Bond Coat Surface Preparation On Thermal Cycling Lifetime And Failure Characteristics Of Thermal Barrier Coatings, Jing Liu Jan 2004

Effects Of Bond Coat Surface Preparation On Thermal Cycling Lifetime And Failure Characteristics Of Thermal Barrier Coatings, Jing Liu

Electronic Theses and Dissertations

Thermal barrier coatings (TBCs) have been widely used in gas turbine engines to protect the underlying metal from high operating temperature so as to improve the durability of the components and enhance the engine efficiency. However, since the TBCs always operate in a demanding high-temperature environment of aircraft and industrial gas-turbine engines, a better understanding of this complex system is required to improve the durability and reliability. The objective of this study is to investigate the effects of surface modification for the NiCoCrAlY bond coats on the thermal cycling lifetime and failure characteristics of TBCs. Parameters of modification for the …


Depth From Defocused Motion, Zarina Myles Jan 2004

Depth From Defocused Motion, Zarina Myles

Electronic Theses and Dissertations

Motion in depth and/or zooming causes defocus blur. This work presents a solution to the problem of using defocus blur and optical flow information to compute depth at points that defocus when they move. We first formulate a novel algorithm which recovers defocus blur and affine parameters simultaneously. Next we formulate a novel relationship (the blur-depth relationship) between defocus blur, relative object depth and three parameters based on camera motion and intrinsic camera parameters. We can handle the situation where a single image has points which have defocused, got sharper or are focally unperturbed. Moreover, our formulation is valid regardless …


Globally-Asynchronous, Locally-Synchronous Wrapper Configurations For, Akarsh Ravi Jan 2004

Globally-Asynchronous, Locally-Synchronous Wrapper Configurations For, Akarsh Ravi

Electronic Theses and Dissertations

Globally-Asynchronous, Locally-Synchronous (GALS) design techniques employ the finer points of synchronous and asynchronous design methods to eliminate problems arising due to clock distribution, power dissipation, and large area over head. With the recent rise in the demand for System-on-a-Chip (SoC) designs, global clock distribution and power dissipation due to clock distribution are inevitable. In order to reduce/eliminate the effects of the global clock in synchronous designs and large area overhead in asynchronous designs, an alternative approach would be to utilize GALS design techniques. Not only do GALS designs eliminate the issue of using a global clock, they also have smaller …


Development Of Titanium Nitride/Molybdenum Disulphide Composite Tribological Coatings For Cryocoolers, Anil Pai Jan 2004

Development Of Titanium Nitride/Molybdenum Disulphide Composite Tribological Coatings For Cryocoolers, Anil Pai

Electronic Theses and Dissertations

Hydrogen is a clean and sustainable form of carrier of energy that can be used in mobile and stationary applications. At present hydrogen is produced mostly from fossil sources. Solar photoelectrochemical processes are being developed for hydrogen production. Storing hydrogen can be done in three main ways: in compressed form, liquid form and by chemical bonding. Near term spaceport operations are one of the prominent applications for usage of large quantities of liquid hydrogen as a cryogenic propellant. Efficient storage and transfer of liquid hydrogen is essential for reducing the launch costs. A Two Stage Reverse Turbo Brayton Cycle (RTBC) …


Circuit Design And Reliability Of A Cmos Receiver, Hong Yang Jan 2004

Circuit Design And Reliability Of A Cmos Receiver, Hong Yang

Electronic Theses and Dissertations

This dissertation explores CMOS RF design and reliability for portable wireless receivers. The objective behind this research is to achieve an increase in integration level, and gain more understanding for RF reliability. The fields covered include device, circuit and system. What is under investigation is a multi-band multi-mode receiver with GSM, DCS-1800 and CDMA compatibility. To my understanding, GSM and CDMA dual-mode mobile phones are progressively investigated in industries, and few commercial products are available. The receiver adopts direct conversion architecture. Some improved circuit design methods are proposed, for example, for low noise amplifier (LNA). Except for band filters, local …


Inverse Boundary Element/Genetic Algorithm Method For Reconstruction O, Mahmood Silieti Jan 2004

Inverse Boundary Element/Genetic Algorithm Method For Reconstruction O, Mahmood Silieti

Electronic Theses and Dissertations

A methodology is formulated for the solution of the inverse problem concerned with the reconstruction of multi-dimensional heat fluxes for film cooling applications. The motivation for this study is the characterization of complex thermal conditions in industrial applications such as those encountered in film cooled turbomachinery components. The heat conduction problem in the metal endwall/shroud is solved using the boundary element method (bem), and the inverse problem is solved using a genetic algorithm (ga). Thermal conditions are overspecified at exposed surfaces amenable to measurement, while the temperature and surface heat flux distributions are unknown at the film cooling hole/slot walls. …


Slope Stability Analysis Of Class I Landfills With Co Disposal Of Bios, Mrutyunjay Vajirkar Jan 2004

Slope Stability Analysis Of Class I Landfills With Co Disposal Of Bios, Mrutyunjay Vajirkar

Electronic Theses and Dissertations

Land filling provides a major, safe, and economical disposal route for biosolids and sludges. With an expanding world, the demand for larger and higher capacity landfills is rapidly increasing. Proper analysis and design on such fills have pushed the boundaries of geotechnical engineering practice, in terms of proper identification and assessment of strength and deformation characteristics of waste materials. The engineering properties of Municipal Solid Waste (MSW) with co-disposal of biosolids and sludges with regards to moisture characteristics and geotechnical stability are of utmost importance. Significant changes in the composition and characteristics of landfill may take place with the addition …


A Balanced Scorecard Template For Florida Incubators, Julio Agustin Lujambio Jan 2004

A Balanced Scorecard Template For Florida Incubators, Julio Agustin Lujambio

Electronic Theses and Dissertations

Incubators are organizations that have become a key factor to the success of new ventures. One study jointly sponsored by the University of Michigan, Ohio University, the National Business Incubation Association, and the Southern Technology Council found that 87% of the firms that went through an incubator program remain in business and 84% remain in their community. Clearly properly run incubators can provide much benefit. However there is littleconsensus on goals and best practices for managing the incubators themselves. Recently an approach to integrating strategy and practice called the balanced scorecard (BSC) has emerged asa popular tool in many public …


Concentration And Velocity Fields Throughout The Flow Field Of Swirling Flows In Gas Turbine Mixers, Louis James Turek Jan 2004

Concentration And Velocity Fields Throughout The Flow Field Of Swirling Flows In Gas Turbine Mixers, Louis James Turek

Electronic Theses and Dissertations

Air velocity and fuel concentration data have been collected throughout the flow fields of two gas turbine mixers in an effort to better understand the mixing of fuel and air in gas turbine mixers. The two gas turbine mixers consisted of an annular flow profile and incorporated swirl vanes to produce a swirling flow to promote fuel/air mixing. The fuel was injected into the bulk flow from the pressure side of the swirl vanes. The first mixer had a swirl angle of 45°, while the second had a swirl angle of 55°. In order to examine the effect of the …