Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 31 - 60 of 144

Full-Text Articles in Engineering

Investigation Of Ground Penetrating Radar For Detection Of Leaking Pipelines Under Roadway Pavements And Development Of Fiber-Wrapping Repair Technique, Pedro F. Suarez Jan 2004

Investigation Of Ground Penetrating Radar For Detection Of Leaking Pipelines Under Roadway Pavements And Development Of Fiber-Wrapping Repair Technique, Pedro F. Suarez

Electronic Theses and Dissertations

Nowadays, it has become a common practice to observe urban roadways undergo severe distress characterized by substantial depressions. In some cases, these pavement depressions are caused by leakages in the connecting joints of sewage pipelines laid beneath the roadway pavement. Manual inspection of pipe leakages has become costly and complex since sewage pipes with relative small diameters do not allow inspection from inside and digging may be required. On the other hand, pipes with large diameters, in which inspection can be made from pipe interior, inspector can not remain inside of the pipe for long periods of time because of …


Modeling And Analysis Of Solar Arrays For Grid Connected Systems With Maximum Power Point Tracking, Adje Mensah Jan 2004

Modeling And Analysis Of Solar Arrays For Grid Connected Systems With Maximum Power Point Tracking, Adje Mensah

HIM 1990-2015

The shrinking of the world’s energy sources has prompted an unprecedented interest in renewable and clean energy sources such as photovoltaic (solar) array. Already popular in space and some industrial power system applications, photovoltaic arrays have yet to become a viable source of energy for most terrestrial applications. For several decades now, engineers have been striving to design reliable and affordable solar array based power systems. One popular approach to achieve reliability is the integration of Maximum Power Point Tracking (MPPT) technology in solar power system design. The purpose of this study was to gain more insight into the nature …


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 …


Forecasting The Onset Of Cloud-Ground Lightning Using S-Pol And Nldn Data, Kartik Ramakrishnan Jan 2004

Forecasting The Onset Of Cloud-Ground Lightning Using S-Pol And Nldn Data, Kartik Ramakrishnan

Electronic Theses and Dissertations

The maximum number of thunderstorms in the United States occur in Central Florida. The cloud-ground lightning from these storms is responsible for extensive damage to life and property. The lightning from these storms is also responsible for delays and cancellations of space shuttle launch attempts at the Kennedy Space Center (KSC) and the 45th Space Wing unmanned launches at Cape Canaveral launch facilities. For these and other reasons accurate forecasting of cloud-ground lightning is of crucial importance. The second phase of NASA's Tropical Rainfall Measuring Mission Texas and Florida Underflights project (TEFLUN-B) was conducted between 1st August and 30th September, …


Toward Building A Social Robot With An Emotion-Based Internal Control, Andreas Marpaung Jan 2004

Toward Building A Social Robot With An Emotion-Based Internal Control, Andreas Marpaung

Electronic Theses and Dissertations

In this thesis, we aim at modeling some aspects of the functional role of emotions on an autonomous embodied agent. We begin by describing our robotic prototype, Cherry--a robot with the task of being a tour guide and an office assistant for the Computer Science Department at the University of Central Florida. Cherry did not have a formal emotion representation of internal states, but did have the ability to express emotions through her multimodal interface. The thesis presents the results of a survey we performed via our social informatics approach where we found that: (1) the idea of having emotions …


Location Of Sinkhole Confining Breach Using Groundwater Flow Patterns Derived From Cone Penetration Testing, Natalie Romina Marinuzzi Jan 2004

Location Of Sinkhole Confining Breach Using Groundwater Flow Patterns Derived From Cone Penetration Testing, Natalie Romina Marinuzzi

Electronic Theses and Dissertations

Dynamic forces in the hydrologic cycle move underground water through Florida's carbonate rocks dissolving chemical components of the rocks, leaving behind caves, solution pipes, and other voids that result in a karst terrain. Ravelling is the common subsidence mechanism throughout most of Florida where unconsolidated materials filter downward into voids in the underlying limestone. A cavity in the overburden develops and enlarges over a period of many years. The enlarged cavity is also known as sinkhole. The investigations of sinkhole characteristics and potential involve studying the regional geology, hydrology and mapping historic sinkholes that have occurred in the area. Use …


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. …


Web-Based Circuit Design Simulation Package For Solving Electrical Eng, Shadi Harb Jan 2004

Web-Based Circuit Design Simulation Package For Solving Electrical Eng, Shadi Harb

Electronic Theses and Dissertations

A Web-based circuit design package has been improved and evaluated to provide students with an enhanced and innovative teaching tools package for the electrical circuit design course. The project objectives can be summarized as follows: 1) developing enhanced problem solving skills using a Web-based environment, 2) developing the design skills and sharpening the critical thinking process, 3) developing a generic and comprehensive teaching/learning circuit package as an extention to the Electrical Engineering virtual lab environment, which gives students the capability to practice and experience all the circuit design skills with minimum cost and effort. The project provides the students with …


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. …


Reduced Kinetic Mechanisms For Premixedhydrogen-Air-Cf3br Flames, Yi Zhang Jan 2004

Reduced Kinetic Mechanisms For Premixedhydrogen-Air-Cf3br Flames, Yi Zhang

Electronic Theses and Dissertations

Halon 1301 (CF3Br), or bromotrifluoromethane, had been widely used as fire-extinguishing agent for many years before its production and consumption were severely regulated by the Montreal Protocol due to its hazardous depletion effect to the stratospheric ozone layer. It is therefore imperative to find an effective replacement fire-fighting agent before the mandated deadline of the complete phase out of CF3Br. Currently there are intensive efforts in searching for an environmentally acceptable fire suppression replacement. This, however, is hampered by a lack of fundamental understanding of how CF3Br suppresses the chemical reactions in a flame environment so effectively. Recent experimental evidence …


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 …


Dewatering Of Biosolids By Sodium Ferrate, Andrea Rios Jan 2004

Dewatering Of Biosolids By Sodium Ferrate, Andrea Rios

Electronic Theses and Dissertations

This study was conducted to evaluate the effectiveness of the liquid form of ferrate for dewatering of biosolids from wastewater treatment facilities. Two different ferrate products prepared using calcium hypochlorite and sodium hypochlorite were used. Samples of anaerobic digested sludge and waste activated sludge with solids content of 2.1% and 0.95 %, respectively were conditioned with both products to evaluate and compare their effectiveness. Centrifugation and filtration of the sludge after conditioning were used. For centrifugation the volume reduction and the turbidity of the supernatant after centrifugation were evaluated. For filtration, the Capillary Suction Time test was used. The optimum …


Biostability In Drinking Water Distribution Systems Study At Pilot-Scale, Michael Le Puil Jan 2004

Biostability In Drinking Water Distribution Systems Study At Pilot-Scale, Michael Le Puil

Electronic Theses and Dissertations

Biostability and related issues (e.g. nitrification) were investigated for 18 months in 18 pilot distribution systems, under various water quality scenarios. This study specifically investigated the impact of steady-state water changes on HPC levels in chlorinated and chloraminated distribution systems. Chlorination was more effective than chloramination in reducing HPC levels (1-2 log difference). There was a rapid increase in HPC corresponding to the change in steady-state water quality, which was observed in all PDS. Modeling effort demonstrated that HPC levels reached a maximum within five days after water quality change and return to initial level ten days after the change. …


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 …


Basic Study Of Micromachined Dep (Dielectrophoretic) Manipulator, Vivek Sundaram Jan 2004

Basic Study Of Micromachined Dep (Dielectrophoretic) Manipulator, Vivek Sundaram

Electronic Theses and Dissertations

The capability of manipulating microparticle in small volumes is fundamental to many biological and medical applications, including separation and detection of cells. The development of microtools for effective sample handling and separation in such volumes is still a challenge. DEP (dielectrophoresis) is one of the most widely used methods in handling the microparticles. In this thesis we show that forces generated by nonuniform electric field (DEP) can be used for trapping and separating the microparticles (latex beads). This work further explores the DEP force based on different electrode geometries and medium conductivity. A micromanipulator for latex bead separation was designed, …


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 …


Hydrogen Sulfide Flux Measurements And Dispersion Modeling From Constr, Sangho Eun Jan 2004

Hydrogen Sulfide Flux Measurements And Dispersion Modeling From Constr, Sangho Eun

Electronic Theses and Dissertations

Odor problems are a common complaint from residents living near landfills. Many compounds can cause malodorous conditions. However, hydrogen sulfide (h2s) has been identified as a principal odorous component from construction and demolition (c&d)debris landfills. Although several studies have reported the ambient concentrations of h2s near c&d landfills, few studies have quantified emission rates of h2s. The most widely used and proven technique for measuring gas emission rates from landfills is the flux chamber method. Typically the flux chamber is a cylindrical enclosure device with a spherical top which limits the gas emission area. Pure zero grade air is introduced …


Automatic Annotation Of Database Images For Query-By-Concept, Nualsawat Hiransakolwong Jan 2004

Automatic Annotation Of Database Images For Query-By-Concept, Nualsawat Hiransakolwong

Electronic Theses and Dissertations

As digital images become ubiquitous in many applications, the need for efficient and effective retrieval techniques is more demanding than ever. Query by Example (QBE) and Query by Concept (QBC) are among the most popular query models. The former model accepts example images as queries and searches for similar ones based on low-level features such as colors and textures. The latter model allows queries to be expressed in the form of high-level semantics or concept words, such as "boat" or "car," and finds images that match the specified concepts. Recent research has focused on the connections between these two models …


Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino Jan 2004

Autonomous Robotic Automation Systemwith Vision Feedback, Jeffery Rosino

Electronic Theses and Dissertations

In this thesis, a full design, development and application of an autonomous robotic automation system using vision feedback is performed. To realize this system, a cylindrical manipulator configuration is implemented, using a personal computer (PC) based PID controller from National Instruments. Full autonomous control will be achieved via a programmable human machine interface (HMI) developed on a PC using Borland C++ Builder. The vision feedback position control is accomplished using an ordinary "off-the-shelf" web camera. The manuscript is organized as follows; After Chapter 1, an introduction to automation history and its role in the manufacturing industry, Chapter 2 discusses and …


The Removal Of Motion Artifacts From Non-Invasive Blood Pressure Measurements, Paresh Thakkar Jan 2004

The Removal Of Motion Artifacts From Non-Invasive Blood Pressure Measurements, Paresh Thakkar

Electronic Theses and Dissertations

Modern Automatic Blood Pressure Measurement Techniques are based on measuring the cuff pressure and on sensing the pulsatile amplitude variations. These measurements are very sensitive to motion of the patient or the surroundings where the patient is. The slightest unexpected movements could offset the readings of the automatic Blood Pressure meter by a large amount or render the readings totally meaningless. Every effort must be taken to avoid subjecting the body of the patient or the patient's surroundings to motion for obtaining a reliable reading. But there are situations in which we need Blood Pressure Measurements with the patient or …


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 …


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 …


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 …


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 …


Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat Jan 2004

Polarimetric Characterization Of Random Electromagnetic Beams And Applications, Mircea Mujat

Electronic Theses and Dissertations

Polarimetry is one of the principal means of investigating the interaction of light with matter. Theoretical models and experimental techniques are presented in this dissertation for polarimetric characterization of random electromagnetic beams and of signatures of random media in different scattering regimes and configurations. The degree of polarization rather than the full description of the state of polarization is of interest in multiple scattering and free space propagation where the statistical nature and not the deterministic component of light bears the relevant information. A new interferometric technique for determining the degree of polarization by measuring the intensity fluctuations in a …


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. …


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 …


Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao Jan 2004

Modeling Of Membrane Solute Mass Transfer In Ro/Nf Membrane Systems, Yu Zhao

Electronic Theses and Dissertations

Five articles describing the impact of surface characteristics, and development of mass transfer models for diffusion controlled membrane applications are published in this dissertation. Article 1 (Chapter 3) describes the impact of membrane surface characteristics and NOM on membrane performance for varying pretreatment and membranes during a field study. Surface charge, hydrophobicity and roughness varied significantly among the four membranes used in the study. Membrane surface characteristics, NOM and SUVA measurements were used to describe mass transfer in a low pressure RO integrated membrane system. Inorganic and organic solute and water mass transfer coefficients were systematically investigated for dependence on …


Sub-Optimal Ultra-Wide Band Receivers, Nilesh Bhuvanendran Jan 2004

Sub-Optimal Ultra-Wide Band Receivers, Nilesh Bhuvanendran

Electronic Theses and Dissertations

Ultra-wide Band (UWB) has sparked a lot of interest lately from the industry and academia. The growing capacity of the wireless industry is requires a new communication system that satisfies the high data rate which does not interfere with existing RF systems. UWB promises to be this new technology. UWB also promises low power, low cost and flexibility. The UWB Channel opens up a huge new wireless channel with Giga Hertz Capacities as well as the highest spatial capacities measured in bits per hertz per square meter. When properly implemented UWB channel can share spectrum with traditional radio systems without …