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Articles 3481 - 3510 of 4566

Full-Text Articles in Engineering

Fast Algorithms For Fragment Based Completion In Images Of Natural Scenes, Siddharth Rajkumar Borikar Jan 2004

Fast Algorithms For Fragment Based Completion In Images Of Natural Scenes, Siddharth Rajkumar Borikar

Electronic Theses and Dissertations

Textures are used widely in computer graphics to represent fine visual details and produce realistic looking images. Often it is necessary to remove some foreground object from the scene. Removal of the portion creates one or more holes in the texture image. These holes need to be filled to complete the image. Various methods like clone brush strokes and compositing processes are used to carry out this completion. User skill is required in such methods. Texture synthesis can also be used to complete regions where the texture is stationary or structured. Reconstructing methods can be used to fill in large-scale …


Using The Six Sigma Policy Deployment Cycle To Mitigate Project Failur, Archana Magadi Jan 2004

Using The Six Sigma Policy Deployment Cycle To Mitigate Project Failur, Archana Magadi

Electronic Theses and Dissertations

Many organizations are struggling to improve customer-focused quality in today's highly competitive domestic and global markets. At the same time, these organizations have failed to implement the Six Sigma methodology into their daily control and strategic planning processes. Six Sigma deployment failures have been categorized as coming from many sources, both management related and person related. Some of the key management related Six Sigma project failures have been identified and discussed in this research work. For continuous improvement to truly take root, organizations must realize that just successfully applying quality tools on any process will not necessarily provide dramatic results, …


Monolithic Integration Of Dual Optical Elements On High Power Semicond, Laurent Vaissie Jan 2004

Monolithic Integration Of Dual Optical Elements On High Power Semicond, Laurent Vaissie

Electronic Theses and Dissertations

This dissertation investigates the monolithic integration of dual optical elements on high power semiconductor lasers for emission around 980nm wavelength. In the proposed configuration, light is coupled out of the AlGaAs/GaAs waveguide by a low reflectivity grating coupler towards the substrate where a second monolithic optical element is integrated to improve the device performance or functionality. A fabrication process based on electron beam lithography and plasma etching was developed to control the grating coupler duty cycle and shape. The near-field intensity profile outcoupled by the grating is modeled using a combination of finite-difference time domain (FDTD) analysis of the nonuniform …


Data Transmission Scheduling For Distributed Simulation Using Packet A, Juan Vargas-Morales Jan 2004

Data Transmission Scheduling For Distributed Simulation Using Packet A, Juan Vargas-Morales

Electronic Theses and Dissertations

Communication bandwidth and latency reduction techniques are developed for Distributed Interactive Simulation (DIS) protocols. Using logs from vignettes simulated by the OneSAF Testbed Baseline (OTB), a discrete event simulator based on the OMNeT++ modeling environment is developed to analyze the Protocol Data Unit (PDU) traffic over a wireless flying Local Area Network (LAN). Alternative PDU bundling and compression techniques are studied under various metrics including slack time, travel time, queue length, and collision rate. Based on these results, Packet Alloying, a technique for the optimized bundling of packets, is proposed and evaluated. Packet Alloying becomes more active when it is …


General Interference Suppression Technique For Diversity Wireless Rece, Tianyu Yang Jan 2004

General Interference Suppression Technique For Diversity Wireless Rece, Tianyu Yang

Electronic Theses and Dissertations

The area of wireless transceiver design is becoming increasingly important due to the rapid growth of wireless communications market as well as diversified design specifications. Research efforts in this area concentrates on schemes that are capable of increasing the system capacity, providing reconfigurability/reprogrammability and reducing the hardware complexity. Emerging topics related to these goals include Software Defined Radio, Multiple-Input-Multiple-Output (MIMO) Systems, Code Division Multiple Access, Ultra-Wideband Systems, etc. This research adopts space diversity and statistical signal processing for digital interference suppression in wireless receivers. The technique simplifies the analog front-end by eliminating the anti-aliasing filters and relaxing the requirements for …


Energy Aware Design And Analysis For Synchronous And Asynchronous Circuits, Jia Di Jan 2004

Energy Aware Design And Analysis For Synchronous And Asynchronous Circuits, Jia Di

Retrospective Theses and Dissertations

Power dissipation has become a major concern for IC designers. Various low power design techniques have been developed for synchronous circuits. Asynchronous circuits, however. have gained more interests recently due to their benefits in lower noise, easy timing control, etc. But few publications on energy reduction techniques for asynchronous logic are available.

Power awareness indicates the ability of the system power to scale with changing conditions and quality requirements. Scalability is an important figure-of-merit since it allows the end user to implement operational policy. just like the user of mobile multimedia equipment needs to select between better quality and longer …


Adaptive Intelligent User Interfaces With Emotion Recognition, Fatma Nasoz Jan 2004

Adaptive Intelligent User Interfaces With Emotion Recognition, Fatma Nasoz

Electronic Theses and Dissertations

The focus of this dissertation is on creating Adaptive Intelligent User Interfaces to facilitate enhanced natural communication during the Human-Computer Interaction by recognizing users' affective states (i.e., emotions experienced by the users) and responding to those emotions by adapting to the current situation via an affective user model created for each user. Controlled experiments were designed and conducted in a laboratory environment and in a Virtual Reality environment to collect physiological data signals from participants experiencing specific emotions. Algorithms (k-Nearest Neighbor [KNN], Discriminant Function Analysis [DFA], Marquardt-Backpropagation [MBP], and Resilient Backpropagation [RBP]) were implemented to analyze the collected data signals …


Modified Sierpinski Fractal Antenna, Tripti Luintel Jan 2004

Modified Sierpinski Fractal Antenna, Tripti Luintel

Electronic Theses and Dissertations

Fractal antennas have the potential to provide multi-band solution through the property of self similarity that the fractal shape possess. This thesis deals with some modifications of the original Sierpinski fractal patch antenna, providing additional parameters to optimize in order to get the required radiation characteristics. A systematic study of the original Sierpinski monopole was done to gain an insight on the operation and multi-band behavior of the antenna and a similar study was done to find out why the patch version of Sierpinski lacks multi-band behavior. A Sierpinski antenna is designed by merging a grid and the fractal restoring …


Analysis And Integration Of A Debris Model In The Virtual Range Projec, Luis Robledo Jan 2004

Analysis And Integration Of A Debris Model In The Virtual Range Projec, Luis Robledo

Electronic Theses and Dissertations

After the accident of the STS 107 Columbia Space Shuttle, great concern has been focused on the risk associated to the population on the ground. Before this accident happened, re-entry routes as well as risk calculation of were not of public concern. Two issues that have been raised from this lamentable accident relate to spacecraft security and to public safety. The integration of a debris model has been part of the original conceptual architecture of the Virtual Range Project. Its integration has been considered as a specific research due to the complexity of the models and the difficulties to obtain …


Versatility And Customization Of Portable Cmm In Reverse Engineering A, Amar Raja Thiraviam Jan 2004

Versatility And Customization Of Portable Cmm In Reverse Engineering A, Amar Raja Thiraviam

Electronic Theses and Dissertations

Reverse engineering is the technique of gathering scientific knowledge about a part by physically examining it. In the computer aided manufacturing world this is referred to as Part to CAD conversion, where the geometry of physical objects are being captured as Digital 3-D CAD Data. This is vital not only to produce drawing of parts for which no CAD data exists, but also is frequently being used to produce better designs. The industry professionals to achieve this are frequently using Coordinate Measuring Machine [CMM] among other tools. The purpose of this thesis is to demonstrate the versatility of portable CMM …


Evaluation Of A Microwave Radiative Transfer Model For Calculating Sat, Simonetta Thompson Jan 2004

Evaluation Of A Microwave Radiative Transfer Model For Calculating Sat, Simonetta Thompson

Electronic Theses and Dissertations

Remote sensing is the process of gathering and analyzing information about the earth's ocean, land and atmosphere using electromagnetic "wireless" techniques. Mathematical models, known as Radiative Transfer Models (RTM), are developed to calculate the observed radiance (brightness temperature) seen by the remote sensor. The RTM calculated brightness temperature is a function of fourteen environmental parameters, including atmospheric profiles of temperature, pressure and moisture, sea surface temperature, and cloud liquid water. Input parameters to the RTM model include data from NOAA Centers for Environmental Prediction (NCEP), Reynolds weekly Sea Surface Temperature and National Ocean Data Center (NODC) WOA98 Ocean Salinity and …


Thermal Management, Beam Control,And Packaging Designs For High Power, Te-Yuan Chung Jan 2004

Thermal Management, Beam Control,And Packaging Designs For High Power, Te-Yuan Chung

Electronic Theses and Dissertations

Several novel techniques for controlling, managing and utilizing high power diode lasers are described. Low pressure water spray cooling for a high heat flux system is developed and proven to be an ideal cooling method for high power diode laser arrays. In order to enable better thermal and optical performance of diode laser arrays, a new and simple optical element, the beam control prism, is invented. It provides the ability to accomplish beam shaping and beam tilting at the same time. Several low thermal resistance diode packaging designs using beam control prisms are proposed, studied and produced. Two pump cavity …


Analysis Of Fading Characteristics Of A Free Space Optical Channel, Roger Douglas Halbing Jan 2004

Analysis Of Fading Characteristics Of A Free Space Optical Channel, Roger Douglas Halbing

Retrospective Theses and Dissertations

In this thesis we shall consider how well the gamma-gamma theory models the fading of experimental data obtained from two line of sight experiments of 1km and 13km. Frequency Analysis of the intensity fluctuations collected from the different aperture sizes will be compared to the two-scale theory of the gamma-gamma model. Statistical analysis of the channel intensity for different aperture sizes will be performed and the results will be compared to the gamma-gamma theory to determine if the gamma-gamma model is valid over greater distances than has previously been investigated .


Minimization Of Power Dissipation In Digital Circuits Using Pipelining And A Study Of Clock Gating Technique, Ranganath Panchangam Jan 2004

Minimization Of Power Dissipation In Digital Circuits Using Pipelining And A Study Of Clock Gating Technique, Ranganath Panchangam

Electronic Theses and Dissertations

Power dissipation is one of the major design issues of digital circuits. The power dissipated by a circuit affects its speed and performance. Multiplier is one of the most commonly used circuits in the digital devices. There are various types of multipliers available depending upon the application in which they are used. In the present thesis report, the importance of power dissipation in today's digital technology is discussed and the various types and sources of power dissipation have been elaborated. Different types of multipliers have been designed which vary in their structure and amount of power dissipation. The concept of …


Nitrification Investigation And Modeling In The Chloraminated Drinking Water Distribution System, Suibing Liu Jan 2004

Nitrification Investigation And Modeling In The Chloraminated Drinking Water Distribution System, Suibing Liu

Electronic Theses and Dissertations

This dissertation consists of five papers concerning nitrification in chloraminated drinking water distribution systems in a one and a half year field study. Seven finished waters were produced from different treatment processes and distributed to eighteen pilot distribution systems (PDSs) that were made pipes taken from actual distribution systems. Unlined cast iron (UCI), galvanized steel (G), lined cast iron (LCI), and PVC pipes were used to build the PDSs. All finished waters were stabilized and chloraminated before entering the PDSs. This dissertation consists of five major parts. (1) System variations of nitrates, nitrites, DO, pH, alkalinity, temperature, chloramine residuals and …


Study For Development Of A Blast Layer For The Virtual Range Project, Sergio Rosales Jan 2004

Study For Development Of A Blast Layer For The Virtual Range Project, Sergio Rosales

Electronic Theses and Dissertations

In this work we develop a Blast-Propellant-Facility integrated analysis study, which evaluates, by using two different approaches, the blast-related impact of an explosive accident of the Space Shuttle during the first ten seconds after launch at Kennedy Space Center. The blast-related risk associated with an explosion at this stage is high because of the quantity of energy involved in both multiple and complex processes. To do this, one of our approaches employed BlastFX®, a software system that facilitates the estimation of the level of damage to people and buildings, starting from an explosive device and rendering results through a complete …


Evaluation Of The Impacts Of Its Information Strategies On I-4 Corridor, Yueliang Zuo Jan 2004

Evaluation Of The Impacts Of Its Information Strategies On I-4 Corridor, Yueliang Zuo

Electronic Theses and Dissertations

This study evaluated the impacts of ITS information strategies under incident conditions in Interstate 4 (I-4) corridor of Orlando. The analysis was performed using DYNASMART-P software package. The ITS information strategies range from pre-trip information, en-route information, and variable message signs. Simulation covered one hour during the morning peak period. The impacts of ITS information strategies on mobility were evaluated by simulating the performance of various ITS information components (pre-trip information, en-route information, and variable message signs) under incident conditions for the I-4 corridor and comparing the results with the corresponding scenarios in the absence of these components. The traffic …


Autonomous Environmental Mapping In Multi-Agent Uav Systems, Linus Jan Luotsinen Jan 2004

Autonomous Environmental Mapping In Multi-Agent Uav Systems, Linus Jan Luotsinen

Electronic Theses and Dissertations

UAV units are by many researchers and aviation specialists considered the future and cutting edge of modern flight technology. This thesis discusses methods for efficient autonomous environmental mapping in a multi-agent domain. An algorithm that emphasizes on team work by sharing the agents local map information and exploration intentions is presented as a solution to the mapping problem. General theories on how to model and implement rational autonomous behaviour for UAV agents are presented. Three different human and tactical behaviour modeling techniques are evaluated. The author found the CxBR paradigm to be the most interesting approach. Also, in order to …


Processing, Microstructural And Mechanical Characterization Of Mechanically Alloyed Al-Al2o3 Nanocomposites, Pushkar Katiyar Jan 2004

Processing, Microstructural And Mechanical Characterization Of Mechanically Alloyed Al-Al2o3 Nanocomposites, Pushkar Katiyar

Electronic Theses and Dissertations

Aluminum-alumina nanocomposites were synthesized using mechanical alloying of blended component powders of pure constituents. This study was performed on various powder mixtures with aluminum as the matrix and alumina as the reinforcement with volume fractions of 20, 30, and 50 % and Al2O3 particle sizes of 50 nm, 150 nm, and 5 µm. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used for the crystal structure and microstructural characterization of the powders at different stages of milling. Al2O3 powders with 50 nm and 150 nm particle size were predominantly of γ-type, while Al2O3 of 5 µm size was …


Cryptarray A Scalable And Reconfigurable Architecture For Cryptographic Applications, Michael John Lomonaco Jan 2004

Cryptarray A Scalable And Reconfigurable Architecture For Cryptographic Applications, Michael John Lomonaco

Electronic Theses and Dissertations

Cryptography is increasingly viewed as a critical technology to fulfill the requirements of security and authentication for information exchange between Internet applications. However, software implementations of cryptographic applications are unable to support the quality of service from a bandwidth perspective required by most Internet applications. As a result, various hardware implementations, from Application-Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), to programmable processors, were proposed to improve this inadequate quality of service. Although these implementations provide performances that are considered better than those produced by software implementations, they still fall short of addressing the bandwidth requirements of most cryptographic applications …


Multiple Scattering Of Light In Inhomogeneous Media And Applications, Claudia Mujat Jan 2004

Multiple Scattering Of Light In Inhomogeneous Media And Applications, Claudia Mujat

Electronic Theses and Dissertations

Light scattering-based techniques are being developed for non-invasive diagnostics of inhomogeneous media in various fields, such as medicine, biology, and material characterization. However, as most media of interest are highly scattering and have a complex structure, it is difficult to obtain a full analytical solution of the scattering problem without introducing approximations and assumptions about the properties of the system under consideration. Moreover, most of the previous studies deal with idealized scattering situations, rarely encountered in practice. This dissertation provides new analytical, numerical, and experimental solutions to describe subtle effects introduced by the properties of the light sources, and by …


Water Quality Variations During Nitrification In Drinking Water Distribution Systems, David W. Webb Jan 2004

Water Quality Variations During Nitrification In Drinking Water Distribution Systems, David W. Webb

Electronic Theses and Dissertations

This thesis documents the relationship among the major water quality parameters during a nitrification episode. Nitrification unexpectedly occurred in a chloraminated pilot drinking water distribution system practicing with a 4.0 mg/L as Cl2 residual dosed at 4.5:1 Cl2:NH3-N. Surface, ground and sea water were treated and disinfected with monochloramines to produce finished water quality similar to regional utility water quality. PVC, galvanized, unlined cast iron and lined iron pipes were harvested from regional distribution systems and used to build eighteen pilot distribution systems (PDSs). The PDSs were operated at a 5-day hydraulic residence time (HRT) and ambient temperatures. As seasonal …


Optimal Upfc Control And Operations For Power Systems, Xiaohe Wu Jan 2004

Optimal Upfc Control And Operations For Power Systems, Xiaohe Wu

Electronic Theses and Dissertations

The content of this dissertation consists of three parts. In the first part, optimal control strategies are developed for Unified Power Flow Controller (UPFC) following the clearance of fault conditions. UPFC is one of the most versatile Flexible AC Transmission devices (FACTs) that have been implemented thus far. The optimal control scheme is composed of two parts. The first is an optimal stabilization control, which is an open-loop ‘Bang’ type of control. The second is an suboptimal damping control, which consists of segments of ‘Bang’ type control with switching functions the same as those of a corresponding approximate linear system. …


Nascar Restrictor Plate Exhaust Manifold Design Strategies, Matthew John Dollhopf Jan 2004

Nascar Restrictor Plate Exhaust Manifold Design Strategies, Matthew John Dollhopf

Electronic Theses and Dissertations

This paper presents the results of a study on exhaust manifold design for a NASCAR Restrictor plate internal combustion engine. A computer simulation model was developed using Ricardo WAVE software. WAVE is a computer-aided engineering code developed by Ricardo to analyze the dynamics of pressure waves, mass flows and energy losses in ducts, plenums and the intake and exhaust manifolds of various systems and machines. [1] The model was validated against experimental data from a current NASCAR Winston Cup restrictor plate motor. The parameters studied have been exhaust manifold diameters and lengths. A response surface analysis of the simulation output …


Surface Chemistry Of Application Specific Pads And Copper Chemical Mechanical Planarization, Sameer Arun Deshpande Jan 2004

Surface Chemistry Of Application Specific Pads And Copper Chemical Mechanical Planarization, Sameer Arun Deshpande

Electronic Theses and Dissertations

Advances in the interconnection technology have played a key role in the continued improvement of the integrated circuit (IC) density, performance and cost. Copper (Cu) metallization, dual damascenes processing and integration of copper with low dielectric constant material are key issues in the IC industries. Chemical mechanical planarization of copper (CuCMP) has emerged as an important process for the manufacturing of ICs. Usually, Cu-CMP process consists of several steps such as the removal of surface layer by mechanical action of the pad and the abrasive particles, the dissolution of the abraded particles in the CMP solution, and the protection of …


Object Tracking And Activity Recognition In Video Acquired Using Mobile Cameras, Alper Yilmaz Jan 2004

Object Tracking And Activity Recognition In Video Acquired Using Mobile Cameras, Alper Yilmaz

Electronic Theses and Dissertations

Due to increasing demand on deployable surveillance systems in recent years, object tracking and activity recognition are receiving considerable attention in the research community. This thesis contributes to both the tracking and the activity recognition components of a surveillance system. In particular, for the tracking component, we propose two different approaches for tracking objects in video acquired by mobile cameras, each of which uses a different object shape representation. The first approach tracks the centroids of the objects in Forward Looking Infrared Imagery (FLIR) and is suitable for tracking objects that appear small in airborne video. The second approach tracks …


Design And Analysis Of Adaptive And Reconfigurable Antennas For Wireless Communication, Maha Abdelmoneim Mohamed Ali Jan 2004

Design And Analysis Of Adaptive And Reconfigurable Antennas For Wireless Communication, Maha Abdelmoneim Mohamed Ali

Electronic Theses and Dissertations

Modern radar and communication systems have experienced a tremendous increase in the number of antennas onboard, on the ground, and in orbital space. This places a burden due to the confined volume and limited weight requirements especially in space applications. The reconfigurable antenna is a promising and exciting new type of antenna, where through the use of appropriate switches the antenna can be structurally reconfigured, to maintain the elements near their resonant dimensions for several frequency bands. This increases the bandwidth of the antenna dramatically, which enables the use of one antenna for several applications. Four novel reconfigurable antenna elements …


Application Of Absorptive Treatments On Traffic Noise Barriers In Florida, Chin Boon Chua Jan 2004

Application Of Absorptive Treatments On Traffic Noise Barriers In Florida, Chin Boon Chua

Electronic Theses and Dissertations

In this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier insertion loss. The best fit equation model was then used to test against measured/model result and TNM prediction results for its …


Evolving Models From Observed Human Performance, Hans Karl Gustav Fernlund Jan 2004

Evolving Models From Observed Human Performance, Hans Karl Gustav Fernlund

Electronic Theses and Dissertations

To create a realistic environment, many simulations require simulated agents with human behavior patterns. Manually creating such agents with realistic behavior is often a tedious and time-consuming task. This dissertation describes a new approach that automatically builds human behavior models for simulated agents by observing human performance. The research described in this dissertation synergistically combines Context-Based Reasoning, a paradigm especially developed to model tactical human performance within simulated agents, with Genetic Programming, a machine learning algorithm to construct the behavior knowledge in accordance to the paradigm. This synergistic combination of well-documented AI methodologies has resulted in a new algorithm that …


Inelastic Dynamic Behavior And Design Of Hybrid Coupled Wall Systems, Mohamed Hassan Jan 2004

Inelastic Dynamic Behavior And Design Of Hybrid Coupled Wall Systems, Mohamed Hassan

Electronic Theses and Dissertations

A key consideration in seismic design of buildings is to ensure that the lateral load resisting system has an appropriate combination of strength, stiffness and energy dissipation capacity. Hybrid coupled wall systems, in which steel beams are used to couple two or more reinforced concrete shear walls in series, can be designed to have these attributes and therefore have the potential to deliver good performance under severe seismic loading. This research presents an investigation of the seismic behavior of this type of structural system. System response of 12- and 18-story high prototypes is studied using transient finite element analyses that …