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Full-Text Articles in Engineering

Modeling Lane-Based Traffic Flow In Emergency Situations In The Presence Of Multiple Heterogeneous Flows, Amani Saleh Jan 2008

Modeling Lane-Based Traffic Flow In Emergency Situations In The Presence Of Multiple Heterogeneous Flows, Amani Saleh

Electronic Theses and Dissertations

In recent years, natural, man-made and technological disasters have been increasing in magnitude and frequency of occurrence. Terrorist attacks have increased after the September 11, 2001. Some authorities suggest that global warming is partly the blame for the increase in frequency of natural disasters, such as the series of hurricanes in the early-2000's. Furthermore, there has been noticeable growth in population within many metropolitan areas not only in the US but also worldwide. These and other facts motivate the need for better emergency evacuation route planning (EERP) approaches in order to minimize the loss of human lives and property. This …


Alayzing The Effects Of Modularity On Search Spaces, Ozlem Garibay Jan 2008

Alayzing The Effects Of Modularity On Search Spaces, Ozlem Garibay

Electronic Theses and Dissertations

We are continuously challenged by ever increasing problem complexity and the need to develop algorithms that can solve complex problems and solve them within a reasonable amount of time. Modularity is thought to reduce problem complexity by decomposing large problems into smaller and less complex subproblems. In practice, introducing modularity into evolutionary algorithm representations appears to improve search performance; however, how and why modularity improves performance is not well understood. In this thesis, we seek to better understand the effects of modularity on search. In particular, what are the effects of module creation on the search space structure and how …


Comparison Of Theoretical Models Of Power Spectral Density To The Experimental Value For Spectrum Of Irradiance Fluctuations, Craig Hershberger Jan 2008

Comparison Of Theoretical Models Of Power Spectral Density To The Experimental Value For Spectrum Of Irradiance Fluctuations, Craig Hershberger

Electronic Theses and Dissertations

A propagation experiment was designed, assembled, and conducted on an extended range to verify theoretical temporal models for weak to strong fluctuation theory. Laser light intensity was propagated over terrain at the Kennedy Space Center (Florida), and detected using optical receivers at a distance of 13.3 Km from the optical source. The intensity data from the experiment was used to generate an experimental Power Spectral Density (PSD) function. The theoretical Mutual Coherence Function (MCF) and Wave Structure Function (WSF) as set forth by Andrews/Phillips , were evaluated to determine the effective relationship between the statistical moments of the random optical …


Data Communication With A Nano-Satellite Using Satellite Personal Communication Networks (S-Pcns), Khudeja Khan Jan 2008

Data Communication With A Nano-Satellite Using Satellite Personal Communication Networks (S-Pcns), Khudeja Khan

Electronic Theses and Dissertations

Satellites typically communicate with locations on the ground to receive commands and send data back. Establishing reliable communications generally requires dedicated ground stations, which in turn require hardware and expertise. Developers of nano-satellites, however, may not have the expertise or resources necessary for establishing a dedicated ground station. Therefore, the use of an existing communication system, such as the Satellite Personal Communication Networks (S-PCNs), is attractive. Another shortcoming of the fixed ground stations, already available, is that they are normally only able to communicate with Low Earth Orbit (LEO) nano-satellites four times per day (two10-minute windows separated by 90 minutes, …


Vcluster: A Portable Virtual Computing Library For Cluster Computing, Hua Zhang Jan 2008

Vcluster: A Portable Virtual Computing Library For Cluster Computing, Hua Zhang

Electronic Theses and Dissertations

Message passing has been the dominant parallel programming model in cluster computing, and libraries like Message Passing Interface (MPI) and Portable Virtual Machine (PVM) have proven their novelty and efficiency through numerous applications in diverse areas. However, as clusters of Symmetric Multi-Processor (SMP) and heterogeneous machines become popular, conventional message passing models must be adapted accordingly to support this new kind of clusters efficiently. In addition, Java programming language, with its features like object oriented architecture, platform independent bytecode, and native support for multithreading, makes it an alternative language for cluster computing. This research presents a new parallel programming model …


Impact Of Construction On Freeway Traffic Operations, Seema Jagtap Jan 2008

Impact Of Construction On Freeway Traffic Operations, Seema Jagtap

Electronic Theses and Dissertations

This study provides an insight into the impact of construction activities on traffic operations. Specifically, the topic of interest for this thesis is to study the impact of construction on traffic operations for construction projects on Interstate 4 from SR 434 to John Young Parkway, from SR 528 to SR 535, and from SR 482 to SR 528. These three projects were chosen because they were the only projects on Interstate 4 where both construction data and loop detector data were available for analysis. The data was collected by examining the Florida Department of Transportation daily inspection reports which had …


A Multi-Objective No-Regret Decision Making Model With Bayesian Learning For Autonomous Unmanned Systems, Matthew Howard Jan 2008

A Multi-Objective No-Regret Decision Making Model With Bayesian Learning For Autonomous Unmanned Systems, Matthew Howard

Electronic Theses and Dissertations

The development of a multi-objective decision making and learning model for the use in unmanned systems is the focus of this project. Starting with traditional game theory and psychological learning theories developed in the past, a new model for machine learning is developed. This model incorporates a no-regret decision making model with a Bayesian learning process which has the ability to adapt to errors found in preconceived costs associated with each objective. This learning ability is what sets this model apart from many others. By creating a model based on previously developed human learning models, hundreds of years of experience …


Novel Complex Adaptive Signal Processing Techniques Employing Optimally Derived Time-Varying Convergence Factors With Applicatio, Raghuram Ranganathan Jan 2008

Novel Complex Adaptive Signal Processing Techniques Employing Optimally Derived Time-Varying Convergence Factors With Applicatio, Raghuram Ranganathan

Electronic Theses and Dissertations

In digital signal processing in general, and wireless communications in particular, the increased usage of complex signal representations, and spectrally efficient complex modulation schemes such as QPSK and QAM has necessitated the need for efficient and fast-converging complex digital signal processing techniques. In this research, novel complex adaptive digital signal processing techniques are presented, which derive optimal convergence factors or step sizes for adjusting the adaptive system coefficients at each iteration. In addition, the real and imaginary components of the complex signal and complex adaptive filter coefficients are treated as separate entities, and are independently updated. As a result, the …


Development Of Hydraulic And Soil Properties For Soil Amendments And Native Soils For Retention Ponds In Marion County, Florida, Lisa Naujock Jan 2008

Development Of Hydraulic And Soil Properties For Soil Amendments And Native Soils For Retention Ponds In Marion County, Florida, Lisa Naujock

Electronic Theses and Dissertations

The vadose zone plays an important role in managing stormwater. Predicting the water balance and water movement is crucial in ground water remediation to keep water suitable for use. To aid in understanding soils ability to transmit and store water, soil and hydraulic properties were analyzed for soils in Marion County, Florida, and potential soil amendments. Soil and hydraulic properties were examined for two soil amendments and for the soils in Marion County, Florida, at the South Oak and the Hunter's Trace locations. The hydraulic properties measured were the soil moisture retention curve (SMRC) and saturated hydraulic conductivity (Ks). The …


A Low Phase Noise K-Band Oscillator Utilizing An Embedded Dielectric Resonator On Multilayer High Frequency Laminates, Ajay Subramanian Jan 2008

A Low Phase Noise K-Band Oscillator Utilizing An Embedded Dielectric Resonator On Multilayer High Frequency Laminates, Ajay Subramanian

Electronic Theses and Dissertations

K-Band (18 to 26 GHz) dielectric resonator oscillators are typically used as a local oscillator in most K-Band digital transmitter/receiver topologies. Traditionally, the oscillator itself is made up of an active device, a dielectric resonator termination network, and a passive load matching network. The termination network embodies a cylindrical high permittivity dielectric resonator that is coupled on the same plane as a current carrying transmission line. This configuration provides an adequate resonance needed for oscillation but has some limitations. In order to provide a high Q resonance the entire oscillator is placed in a metal box to prevent radiation losses. …


Reducing Effluent Phosphorus And Nitrogen Concentrations From A Stormwater Detention Pond Using A Chamber Upflow Filter And Skim, Patrick Ryan Jan 2008

Reducing Effluent Phosphorus And Nitrogen Concentrations From A Stormwater Detention Pond Using A Chamber Upflow Filter And Skim, Patrick Ryan

Electronic Theses and Dissertations

Stormwater runoff is a known pollutant source capable of causing surface water degradation, especially in highly populated areas such as Central Florida. Wet detention ponds manage this stormwater, but most of the ponds do not remove enough nutrients, specifically nitrogen and phosphorus, to meet TMDL regulations. This research provides a possible addition to a detention pond in Seminole County, Florida using a Chamber Upflow Filter and Skimmer (CUFS), which can increase the removal of phosphorus and nitrogen by the system. Water enters the system through the skimmer, which floats on the surface of the detention pond. It travels from the …


Semantic Video Retrieval Using High Level Context, Yusuf Aytar Jan 2008

Semantic Video Retrieval Using High Level Context, Yusuf Aytar

Electronic Theses and Dissertations

Video retrieval - searching and retrieving videos relevant to a user defined query - is one of the most popular topics in both real life applications and multimedia research. This thesis employs concepts from Natural Language Understanding in solving the video retrieval problem. Our main contribution is the utilization of the semantic word similarity measures for video retrieval through the trained concept detectors, and the visual co-occurrence relations between such concepts. We propose two methods for content-based retrieval of videos: (1) A method for retrieving a new concept (a concept which is not known to the system and no annotation …


A Time-Varying Radiometric Bias Correction For The Trmm Microwave Imager, Kaushik Gopalan Jan 2008

A Time-Varying Radiometric Bias Correction For The Trmm Microwave Imager, Kaushik Gopalan

Electronic Theses and Dissertations

This dissertation provides a robust radiometric calibration for the TRMM Microwave Imager to correct systematic brightness temperature errors, which vary dynamically with orbit position (time) and day of the year. The presence of a time-varying bias in TMI is confirmed by inter-calibration with WindSat and SSMI. This time varying bias is manifested as a time of day dependent variation of the relative biases between TMI and both WindSat and SSMI. In this dissertation, we provide convincing evidence that this time-varying Tb bias in TMI is caused by variations in the physical temperature of the emissive TMI reflector antenna. This dissertation …


Automatic Generation Of Supply Chain Simulation Models From Scor Based Ontologies, Dayana Cope Jan 2008

Automatic Generation Of Supply Chain Simulation Models From Scor Based Ontologies, Dayana Cope

Electronic Theses and Dissertations

In today's economy of global markets, supply chain networks, supplier/customer relationship management and intense competition; decision makers are faced with a need to perform decision making using tools that do not accommodate the nature of the changing market. This research focuses on developing a methodology that addresses this need. The developed methodology provides supply chain decision makers with a tool to perform efficient decision making in stochastic, dynamic and distributed supply chain environments. The integrated methodology allows for informed decision making in a fast, sharable and easy to use format. The methodology was implemented by developing a stand alone tool …


Multiobjective Coordination Models For Maintenance And Service Parts Inventory Planning And Control, Oscar Martinez Jan 2008

Multiobjective Coordination Models For Maintenance And Service Parts Inventory Planning And Control, Oscar Martinez

Electronic Theses and Dissertations

In many equipment-intensive organizations in the manufacturing, service and particularly the defense sectors, service parts inventories constitute a significant source of tactical and operational costs and consume a significant portion of capital investment. For instance, the Defense Logistics Agency manages about 4 million consumable service parts and provides about 93% of all consumable service parts used by the military services. These items required about US$1.9 billion over the fiscal years 1999-2002. During the same time, the US General Accountability Office discovered that, in the United States Navy, there were about 3.7 billion ship and submarine parts that were not needed. …


Quantitative Thickness Mapping In High-Angle Annular Dark-Field (Haadf) Scanning Transmission Electron Microscopy (Stem), Haritha Nukala Jan 2008

Quantitative Thickness Mapping In High-Angle Annular Dark-Field (Haadf) Scanning Transmission Electron Microscopy (Stem), Haritha Nukala

Electronic Theses and Dissertations

Only a few methods are currently available for the measurement of sample thicknesses in Transmission Electron Microscopy (TEM). These methods, Convergent-Beam Electron Diffraction (CBED) and thickness mapping in Energy-Filtered TEM (EFTEM), are either elaborate or complex. In this present work, I have investigated and come up with a simple straight-forward method to measure the local thickness of a TEM sample with the atomic number (Z-contrast) imaging using High-Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM). HAADF STEM shows atomic number contrast for high scattering angles of the electrons, owing to predominant electron scattering at the potential of the …


A Surrogate Measure Of Customer Satisfaction In The Manufacture Of Printed Wiring Boards, Adam Y. Maamoun Jan 2008

A Surrogate Measure Of Customer Satisfaction In The Manufacture Of Printed Wiring Boards, Adam Y. Maamoun

Electronic Theses and Dissertations

The objective of this research is to determine and develop a model that is capable of accurately measuring customer satisfaction for different industries and in particularly for the Printed Wiring Boards (PWB) Manufacturers. The new model will incorporate data not being collected or utilized by the survey method of determining customer satisfaction. The method used is a weighted average of satisfaction among several researched categories with percentages that accurately represent the relative importance of multiple facets of the PWB manufacturers customer satisfaction. A very common term in quality assurance is that "What is not measured accurately can not be evaluated …


Appearance-Driven Material Design, Mark Colbert Jan 2008

Appearance-Driven Material Design, Mark Colbert

Electronic Theses and Dissertations

In the computer graphics production environment, artists often must tweak specific lighting and material parameters to match a mind's eye vision of the appearance of a 3D scene. However, the interaction between a material and a lighting environment is often too complex to cognitively predict without visualization. Therefore, artists operate in a design cycle, where they tweak the parameters, wait for a visualization, and repeat, seeking to obtain a desired look. We propose the use of appearance-driven material design. Here, artists directly design the appearance of reflected light for a specific view, surface point, and time. In this thesis, we …


Developmemnt Of A Modeling And Simulation Training Needs Model For Selected Defense Acquisition Workforce Communities, Lik Chun Peh Jan 2008

Developmemnt Of A Modeling And Simulation Training Needs Model For Selected Defense Acquisition Workforce Communities, Lik Chun Peh

Electronic Theses and Dissertations

The DoD Modeling and Simulation Steering Committee (M&S SC) identified Modeling and Simulation (M&S) as an educational objective for the Acquisition, Technology and Logistics (AT&L) workforce. Notably, past usages of M&S in system acquisitions for both DoD and commercial industry have demonstrated improvements in efficiency and effectiveness over traditional acquisition techniques. However, to achieve expected and consistent performance by this workforce in these new techniques, the M&S essential skill requirements for this workforce may be extensive. This research aims to validate the content and level of competency in selected M&S tools and technology necessary for consistent workforce performance. The notion …


Determining Florida Landfill Odor Buffer Distances Using Aermod, Veronica Figueroa Jan 2008

Determining Florida Landfill Odor Buffer Distances Using Aermod, Veronica Figueroa

Electronic Theses and Dissertations

As U.S. landfills continue to grow in size, concerns about odorous gas emissions from landfills are increasing. For states that are expanding in population, such as Florida, odors from landfills are a major concern because new housing developments, needed to accommodate the rapid population growth, are creeping closer and closer to the existing landfills. As homes get closer to landfills, odor complaints are likely to become more frequent, causing landfill managers increased problems with public interactions. Odor buffer zones around landfills need to be established to give municipalities tools to help prevent the building of future homes too close to …


Production Of Bulk Ceramic Shapes From Polymer Derived Ceramics, Arnold Hill Jan 2008

Production Of Bulk Ceramic Shapes From Polymer Derived Ceramics, Arnold Hill

Electronic Theses and Dissertations

A method has been developed to produce bulk ceramic components from a class of ceramics known as polymer derived ceramics. In the past polymer derived ceramics have been limited to thin film applications or in the fabrication of MEMS devices. The reason being that when the polymer is into a ceramic, large quantities of gas are generated which produce internal pressure that fractures the ceramic components. The method developed here solves that issue by casting into the polymer a 3 dimensional network of polymer fibers in the form of a foam which, during pyrolysis, burns out and leaves a network …


Laser Enhanced Doping For Silicon Carbide White Light Emitting Diodes, Sachin Bet Jan 2008

Laser Enhanced Doping For Silicon Carbide White Light Emitting Diodes, Sachin Bet

Electronic Theses and Dissertations

This work establishes a solid foundation for the use of indirect band gap semiconductors for light emitting application and presents the work on development of white light emitting diodes (LEDs) in silicon carbide (SiC). Novel laser doping has been utilized to fabricate white light emitting diodes in 6H-SiC (n-type N) and 4H-SiC (p-type Al) wafers. The emission of different colors to ultimately generate white light is tailored on the basis of donor acceptor pair (DAP) recombination mechanism for luminescence. A Q-switched Nd:YAG pulse laser (1064 nm wavelength) was used to carry out the doping experiments. The p and n regions …


Integration Of A Nanostructure Embedded Thermoresponsive Polymer For Microfluidic Applications, Ghanashyam Londe Jan 2008

Integration Of A Nanostructure Embedded Thermoresponsive Polymer For Microfluidic Applications, Ghanashyam Londe

Electronic Theses and Dissertations

This work describes the modeling, synthesis, integration and characterization of a novel nanostructure embedded thermoresponsive material for microfluidic applications. The innumerable applications of thermoresponsive surfaces in the recent years have necessitated the development of a rigorous mathematical treatment for these surfaces to understand and improve their behavior. An analytical model is proposed to describe the transfer characteristic (variation of contact angle versus temperature) of a unique switchable, nanostructured, thermoresponsive surface consisting of silica nanoparticles and the thermoresponsive polymer, Poly(N-isopropylacrylamide ) (PNIPAAm) which changes its wetting angle upon heating. Important metrics such as the absolute lower critical solution temperature, threshold & …


An Improved Thermoregulatory Model For Cooling Garment Applications With Transient Metabolic Rates, Johan Westin Jan 2008

An Improved Thermoregulatory Model For Cooling Garment Applications With Transient Metabolic Rates, Johan Westin

Electronic Theses and Dissertations

Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the …


Pressure Losses Experienced By Liquid Flow Through Pdms Microchannels With Abrupt Area Changes, Jonathan Wehking Jan 2008

Pressure Losses Experienced By Liquid Flow Through Pdms Microchannels With Abrupt Area Changes, Jonathan Wehking

Electronic Theses and Dissertations

Given the surmounting disagreement amongst researchers in the area of liquid flow behavior at the microscale for the past thirty years, this work presents a fundamental approach to analyzing the pressure losses experienced by the laminar flow of water (Re = 7 to Re = 130) through both rectangular straight duct microchannels (of widths ranging from 50 to 130 micrometers), and microchannels with sudden expansions and contractions (with area ratios ranging from 0.4 to 1.0) all with a constant depth of 104 micrometers. The simplified Bernoulli equations for uniform, steady, incompressible, internal duct flow were used to compare flow through …


User-Defined Patterning Of Neural Progenitor Cells On 3d Micropillar Arrays Using Round Cross-Sectional Geometry, Specific Dimen, Andrea Wesser Jan 2008

User-Defined Patterning Of Neural Progenitor Cells On 3d Micropillar Arrays Using Round Cross-Sectional Geometry, Specific Dimen, Andrea Wesser

Electronic Theses and Dissertations

The ability to control stem cell functions, particularly neuronal progenitors, has long since been believed to be the key to successful treatment of neurodegenerative disorders such as Alzheimer's, Parkinson's and accidents involving head trauma. The neurology field calls for many new solutions to address the controlled neural stem cell seeding and placement of cells for neural tissue regeneration. Self-assembled monolayers (SAM) from the alkanethiol group provide a straightforward applicable, reliable treatment for cell adhesion. An ODT/gold treatment was used to adhere the cells to patterned areas, due mainly to a high confluence of cells attracted to it, as well as …


Severity Analysis Of Driver Crash Involvements On Multilane High Speed Arterial Corridors, Alexis Nevarez-Pagan Jan 2008

Severity Analysis Of Driver Crash Involvements On Multilane High Speed Arterial Corridors, Alexis Nevarez-Pagan

Electronic Theses and Dissertations

Arterial roads constitute the majority of the centerline miles of the Florida State Highway System. Severe injury involvements on these roads account for a quarter of the total severe injuries reported statewide. This research focuses on driver injury severity analysis of statewide multilane high speed arterials using crash data for the years 2002 to 2004. The first goal is to test different ways of analyzing crash data (by road entity and crash types) and find the best method of driver injury severity analysis. A second goal is to find driver, vehicle, road and environment related factors that contribute to severe …


A Comprehensive Multi-Faceted Approach For Simultaneously Analyzing Organizational Performance Measures Essential For Company Su, Ana Ferreras Jan 2008

A Comprehensive Multi-Faceted Approach For Simultaneously Analyzing Organizational Performance Measures Essential For Company Su, Ana Ferreras

Electronic Theses and Dissertations

Profit, ergonomics, safety, employee morale, quality, efficiency, and productivity are critical components that greatly impact company success within manufacturing organizations. Therefore, it is essential that a valid and reliable systematic approach that encompasses all of these factors be developed for use by top management in today's rapidly changing manufacturing environment. Organizational-level decisions made based upon a single goal or narrow perspective that only considers one of the aforementioned components, such as profit, while ignoring others, such as employee morale, have proven harmful to the long term viability and success of manufacturing companies. Often organizational leaders are not adequately equipped to …


Preparation And Characterisation Of Stabilized Nafion/Phosphotungstic Acid Composite Membranes For Proton Exchange Membrane Fuel Cell (Pemfc) Automobile Engines, Rohit Agarwal Jan 2008

Preparation And Characterisation Of Stabilized Nafion/Phosphotungstic Acid Composite Membranes For Proton Exchange Membrane Fuel Cell (Pemfc) Automobile Engines, Rohit Agarwal

Electronic Theses and Dissertations

Membrane durability is one of the limiting factors for proton exchange membrane fuel cell (PEMFC) commercialisation by limiting the lifetime of the membrane via electrochemical / mechanical / thermal degradation. Lower internal humidity in the membrane at high temperature ( > 100 °C) and low relative humidity (25-50 %RH) operating conditions leads to increased resistance, lowering of performance and higher degradation rate. One of the promising candidates is composite proton exchange membranes (CPEMs) which have heteropoly acid (HPA) e.g. Phosphotungstic acid (PTA) doped throughout the Nafion® matrix. HPA is primarily responsible for carrying intrinsic water which reduces the external water dependence. …


Synthesis And Characterization Of Polymer-Derived Porous Sicn Ceramics, Yun Wei Jan 2008

Synthesis And Characterization Of Polymer-Derived Porous Sicn Ceramics, Yun Wei

Electronic Theses and Dissertations

The synthesis and characterization of porous SiCN ceramics produced by the method of polymer-derived ceramics were studied in this work. The polymer-to-ceramic conversion technique is a novel revolution in the methods for fabricating porous materials with controlled morphologies and tailored properties. The porous SiCN ceramics can be successfully prepared from thermal decomposition of polymeric precursors (polysilazane) and the pore former (polyvinyl alcohol (PVA)). The fabrication procedures involved the mixing of the pre-ceramic precursor with appropriate concentration of the PVA, curing, pyrolysis and subsequent PVA removal, leaving pores in the ceramic matrix. The material obtained revealed a homogeneous amorphous microstructure consisting …