Engineering Commons^™

Multilayer Electret Activated By Direct Contact Silicon Electrode., Mark M. Crain

Electronic Theses and Dissertations

Electrets used in microelectromechanical systems (MEMS) devices are often formed by corona charging, where ionized gases are generated in an electric field to introduce a charge to the electret surface. The purpose of this study was to investigate a new technique for creating an electret from a plasma enhanced chemical vapor deposition (PECVD) multilayer film of SiO2/Si3N4/SiO2 using a direct contact electrode of silicon. The electret formation takes advantage of deep traps in silicon nitride, which are known to develop from hydrogen interactions with silicon dangling bonds and, in some stoichiometries, nitrogen dangling bonds. The electret activation process has been …

Shape/Image Registration For Medical Imaging : Novel Algorithms And Applications., Ahmed Magdy Shalaby 1982-

Electronic Theses and Dissertations

This dissertation looks at two different categories of the registration approaches: Shape registration, and Image registration. It also considers the applications of these approaches into the medical imaging field. Shape registration is an important problem in computer vision, computer graphics and medical imaging. It has been handled in different manners in many applications like shapebased segmentation, shape recognition, and tracking. Image registration is the process of overlaying two or more images of the same scene taken at different times, from different viewpoints, and/or by different sensors. Many image processing applications like remote sensing, fusion of medical images, and computer-aided surgery …

Statistical Scheduling Of Economic Dispatch And Energy Reserves Of Hybrid Power Systems With High Renewable Energy Penetration, Yi Gu

Electronic Theses and Dissertations

A statistical scheduling approach to economic dispatch and energy reserves is proposed in this paper. The proposed approach focuses on minimizing the overall power operating cost with considerations of renewable energy uncertainty and power system security. A hybrid power system generates electricity from both conventional and renewable energy sources. In such a system, it is challenging and yet an open question on the scheduling of economic dispatch together with energy reserves, due to renewable energy generation uncertainty, and spatially wide distribution of energy resources. The hybrid power system scheduling is formulated as a convex programming problem to minimize power operating …

Condition Monitoring System Of Wind Turbine Generators, Khaled Bubaker Abdusamad

Electronic Theses and Dissertations

The development and implementation of the condition monitoring systems (CMS) play a significant role in overcoming the number of failures in the wind turbine generators that result from the harsh operation conditions, such as over temperature, particularly when turbines are deployed offshore. In order to increase the reliability of the wind energy industry, monitoring the operation conditions of wind generators is essential to detect the immediate faults rapidly and perform appropriate preventative maintenance. CMS helps to avoid failures, decrease the potential shutdowns while running, reduce the maintenance and operation costs and maintain wind turbines protected. The knowledge of wind turbine …

Solar Power Deployment: Forecasting And Planning, Mohana Shandal Alanazi

Electronic Theses and Dissertations

The rapid growth of Photovoltaic (PV) technology has been very visible over the past decade. Recently, the penetration of PV plants to the existing grid has significantly increased. Such increase in the integration of solar energy has brought attention to the solar irradiance forecasting. This thesis presents a thorough research of PV technology, how solar power can be forecasted, and PV planning under uncertainty.

Over the last decade, the PV was one of the fastest growing renewable energy technologies. However, the PV system output varies based on weather conditions. Due to the variability and the uncertainty of solar power, the …

Hosting Capacity Calculations In Power Systems, Mansoor T. Alturki

Electronic Theses and Dissertations

The aim of this thesis is to investigate and calculate Hosting Capacity in power systems to identify the maximum amount of renewable energy resources that can be deployed. After connecting distributed generation to distribution system, the performance index of the distribution system will improve or deteriorate. The point which is between the acceptable deterioration and unacceptable deterioration is the hosting capacity. This research is specifically concerned with the effect of increasing distributed generation on the performance index in distribution networks and finding the maximum point of the acceptable deterioration.

The hosting capacity is the amount of distributed generation that can …

Fabrication And Characterization Of Small Scale Photo-Electro-Chemical Solar Cells, Xin Li

Electronic Theses and Dissertations

This thesis presents fabrication and characterization of a small scale photoelectro-chemical (PEC) solar cell.

The cell consists of a p-type silicon cathode with an etched micro-cavity that houses the zinc chloride electrolyte solution, and the cavity is covered by a sheet of zinc acting as the anode. The cell operates using a semiconductor-electrolyte junction instead of the p-n junction of a conventional solid state solar cell. The silicon electrode is fabricated by controlled wet etching so that the bottom of the micro-cavity becomes a very thin membrane, which allows photons to penetrate and reach the semiconductorelectrolyte interface for the generation …

A Comparison Of Two Method For Dg Optimizing In Power System, Yu Li

Electronic Theses and Dissertations

In this paper, we mainly focus on using new method to solve the DG problem in order to reducing the loss. We start from comparing two new method. We list out the mathematics theory of the two methods. And then, we using a 33 bus modeling to show which method has a better function on reducing the loss for system. After that, we take the better method to reducing the loss for two cases (14 bus , 34 bus modeling). At last, we conclude the result of the research and give some comment on the future works.

Thermal And Structural Modeling Of Electrochromics On Glass, Mahesh B. Manandhar

Electronic Theses and Dissertations

Advanced glazing is a type of window glazing that interacts with the surrounding environment to change its thermal and optical properties to create a more comfortable and energy efficient indoor environment. Electrochromics are one type of such advanced glazing materials that change their properties in response to an externally applied voltage controllable by the user or by automation.

The effectiveness of electrochromics depends upon how well it can keep off extreme temperature conditions from outdoors all year round as well as how structurally stable it can remain at such conditions. This research investigates the use of COMSOL, a finite element …

Studies On Efficient Spectrum Sharing In Coexisting Wireless Networks., Guanying Ru

Electronic Theses and Dissertations

Wireless communication is facing serious challenges worldwide: the severe spectrum shortage along with the explosive increase of the wireless communication demands. Moreover, different communication networks may coexist in the same geographical area. By allowing multiple communication networks cooperatively or opportunistically sharing the same frequency will potentially enhance the spectrum efficiency. This dissertation aims to investigate important spectrum sharing schemes for coexisting networks. For coexisting networks operating in interweave cognitive radio mode, most existing works focus on the secondary network’s spectrum sensing and accessing schemes. However, the primary network can be selfish and tends to use up all the frequency resource. …

One-Sided Transparency : A Revolution In Visualization., Robert Curtin

Electronic Theses and Dissertations

Colorectal cancer is one of the leading causes of death in the world. Colonoscopy, the traditional procedure for detecting colorectal cancer, is very effective. It does have downsides, however - it is invasive, uncomfortable for the patient, and not available to some patients with certain conditions. Virtual colonoscopy has been developed in order to address these issues. A virtual colonoscopy (VC) is a non-invasive method for performing a colonoscopy by using medical imaging data to create a virtual representation of the colon. Previous virtual colonoscopy methods include fly-through, fly-over, flattening, and the unfolded cube method. Fly-through moves the camera through …

Design Of The High-Speed Stereo Radiography System, John C. Ivester Iv

Electronic Theses and Dissertations

Orthopaedic pathologies often involve disruption of the mechanical environment of a joint at/below the mm scale. The ability to measure biomechanical kinematics at the sub-mm scale is essential for obtaining valuable insight into pathologies, but small motions of the joints are difficult to quantify. Estimates of skeletal kinematics are commonly made from optical motion capture systems and markers placed on the skin. The error caused by external marker movement is largely avoided with x-ray motion capture. Dynamic radiography uses a series of x-ray images recorded at high-speed and captures in-vivo joint motion. Uncovering the mechanical foundation of orthopaedic pathologies requires …

Study Of Bidirectional Broadband Passive Optical Network (Bpon) Using Edfa, Yasser Almalaq

Electronic Theses and Dissertations

Optical line terminals (OLTs) and number of optical network units (ONUs) are two main parts of passive optical network (PON). OLT is placed at the central office of the service providers, the ONUs are located near to the end subscribers. When compared with point-to-point design, a PON decreases the number of fiber used and central office components required.

Broadband PON (BPON), which is one type of PON, can support high-speed voice, data and video services to subscribers' residential homes and small businesses. In this research, by using erbium doped fiber amplifier (EDFA), the performance of bi-directional BPON is experimented and …

Semi-Blind Robust Indentification And Robust Control Approach To Personalized Anemia Management., Elom Akabua

Electronic Theses and Dissertations

The homeostatic blood hemoglobin (Hb) content of a healthy individual varies between the range of 14-18 g/dL for a male and 12-16 g/dL for a female. This quantity provides an estimate of red blood cell (RBC) count in circulation at any given moment. RBC is a protein carrying substance that transports oxygen from the lungs to other tissues in the body and is synthesized by the kidney through a process known as erythropoiesis where erythropoietin is secreted in response to hypoxia. In this regard, the kidneys act not only as a controller but also as a sensor in regulating RBC …

Fast And Robust Hybrid Framework For Infant Brain Classification From Structural Mri : A Case Study For Early Diagnosis Of Autism., Amir Alansary

Electronic Theses and Dissertations

The ultimate goal of this work is to develop a computer-aided diagnosis (CAD) system for early autism diagnosis from infant structural magnetic resonance imaging (MRI). The vital step to achieve this goal is to get accurate segmentation of the different brain structures: whitematter, graymatter, and cerebrospinal fluid, which will be the main focus of this thesis. The proposed brain classification approach consists of two major steps. First, the brain is extracted based on the integration of a stochastic model that serves to learn the visual appearance of the brain texture, and a geometric model that preserves the brain geometry during …

Analysis Of Contrast-Enhanced Medical Images., Fahmi Abdallah Fahmi Mohammed Khalifa

Electronic Theses and Dissertations

Early detection of human organ diseases is of great importance for the accurate diagnosis and institution of appropriate therapies. This can potentially prevent progression to end-stage disease by detecting precursors that evaluate organ functionality. In addition, it also assists the clinicians for therapy evaluation, tracking diseases progression, and surgery operations. Advances in functional and contrast-enhanced (CE) medical images enabled accurate noninvasive evaluation of organ functionality due to their ability to provide superior anatomical and functional information about the tissue-of-interest. The main objective of this dissertation is to develop a computer-aided diagnostic (CAD) system for analyzing complex data from CE magnetic …

Utilizing Radiation For Smart Robotic Applications Using Visible, Thermal, And Polarization Images., Ali H. Mahmoud

Electronic Theses and Dissertations

The domain of this research is the use of computer vision methodologies in utilizing radiation for smart robotic applications for driving assistance. Radiation can be emitted by an object, reflected or transmitted. Understanding the nature and the properties of the radiation forming an image is essential in interpreting the information in that image which can then be used by a machine e.g. a smart vehicle to make a decision and perform an action. Throughout this work, different types of images are used to help a robotic vehicle make a decision and perform a certain action. This work presents three smart …

Application Of Energy Storage In Power Systems, Khalid M. Alqunun

Electronic Theses and Dissertations

The purpose of this research is to determine the advantages of using energy storage systems. This study presents a model for energy storage in electric power systems. The model involves methods of reducing the operation cost of a power network and the calculation of capital cost of energy storage systems. Two test systems have been considered, the IEEE six-bus system and the IEEE 118-bus system, to analyze the impact of energy storage on power system economic operation. Properties of energy storage have been considered such as rated power investment cost and rated energy investment cost. Mixed integer programming has been …

Impact Of Net Metering On Customers Saving, Abdullah F. Albaker

Electronic Theses and Dissertations

The purpose of this study is to investigate the effects of net metering on customers engagement. Brief discussions about net metering, its purpose, its challenges and benefits, and the history of net metering in the United States are included within the thesis. The thesis illustrates the net-metering rules, regulations and policies in the United States, and it shows that they are applied in 43 states plus the District of Columbia. Nevertheless, It has clearly seen that they are not similar in all states.

The thesis then identifies the impacts of net metering on utilities and solar power owners in particular. …

Three-Dimensional Modeling Of The Human Jaw/Teeth Using Optics And Statistics., Aly Saber Abdelrahim

Electronic Theses and Dissertations

Object modeling is a fundamental problem in engineering, involving talents from computer-aided design, computational geometry, computer vision and advanced manufacturing. The process of object modeling takes three stages: sensing, representation, and analysis. Various sensors may be used to capture information about objects; optical cameras and laser scanners are common with rigid objects, while X-ray, CT and MRI are common with biological organs. These sensors may provide a direct or an indirect inference about the object, requiring a geometric representation in the computer that is suitable for subsequent usage. Geometric representations that are compact, i.e., capture the main features of the …

Next Generation Rfid Telemetry Design For Biomedical Implants., Andre Johan Faul

Electronic Theses and Dissertations

The design and development of a Radio Frequency Identification (RFID) based pressure-sensing system to increase the range of current Intra-Ocular Pressure (IOP) sensing systems is described in this dissertation. A large number of current systems use near-field inductive coupling for the transfer of energy and data, which limits the operational range to only a few centimeters and does not allow for continuous monitoring of pressure. Increasing the powering range of the telemetry system will offer the possibility of continuous monitoring since the reader can be attached to a waist belt or put on a night stand when sleeping. The system …

Development Of A Light-Powered Microstructure : Enhancing Thermal Actuation With Near-Infrared Absorbent Gold Nanoparticles., Thomas Matthew Lucas

Electronic Theses and Dissertations

Development of microscale actuating technologies has considerably added to the toolset for interacting with natural components at the cellular level. Small-scale actuators and switches have potential in areas such as microscale pumping and particle manipulation. Thermal actuation has been used with asymmetric geometry to create large deflections with high force relative to electrostatically driven systems. However, many thermally based techniques require a physical connection for power and operate outside the temperature range conducive for biological studies and medical applications. The work presented here describes the design of an out-of-plane bistable switch that responds to near-infrared light with wavelength-specific response. In …

4d Reduced Te (Rte) Spiral Phase Contrast Nri For Rapid Quantification And Visualization Of Blood Flow And Hemodynamics., Mohammadjavad Negahdar

Electronic Theses and Dissertations

4D flow Phase Contrast MRI is a relatively new technique in MRI which is capable of deriving time-resolved three-dimensional velocity fields in a 3D volume noninvasively. 4D flow imaging is a 3D k-space acquisition where for the third dimension, an additional phase-encoding step is required. The velocity field can then be used to obtain flow waveform, wall shear stress, vascular compliance, blood pressure, and other hemodynamic information. A significant limitation of 4D flow methods has been the requisite long scan times, requiring the patient to remain motionless at times on the order of 10-20 minutes, depending on scan parameters. The …

Low Power Strain Sensor Based On Mos Tunneling Current., Li Zhu

Electronic Theses and Dissertations

Sensors, such as pressure sensors, accelerometers and gyroscopes, are very important components in modern portable electronics. A limited source of power in portable electronics is motivating research on new low power sensors. Piezoresistive and capacitive sensing technologies are the most commonly utilized technologies, which typically consume power in the µW to mW range. Tunneling current sensing is attractive for low power applications because the typical tunneling current is in the nA range. This dissertation demonstrates a low power strain sensor based on the tunneling current in a metal-oxide-semiconductor (MOS) structure with a power consumption of a couple of nano-Watts (nW) …

Parameter Identification Of Micro-Grid Control System, Ning Gao

Electronic Theses and Dissertations

Micro-grid provides an effective means of integrating distributed energy resource (DER) units into the power systems. A micro-grid is defined as an independent low- or medium-voltage distribution network comprising various DER units, power-electronic interfaces, controllable loads, and monitoring and protection devices. Following the development of the renewable energy, micro-grid has attracted much attention.

This thesis emphasizes on the parameter identification of the control system of the micro-grid. The control system plays an important role in the stable operation of the micro-grid. The micro-grid has two operation modes, which are grid-connected operation mode and islanded operation mode. The transition between two …

Identifying Influential Agents In Social Systems, Mahsa Maghami

Electronic Theses and Dissertations

This dissertation addresses the problem of influence maximization in social networks. In- fluence maximization is applicable to many types of real-world problems, including modeling contagion, technology adoption, and viral marketing. Here we examine an advertisement domain in which the overarching goal is to find the influential nodes in a social network, based on the network structure and the interactions, as targets of advertisement. The assumption is that advertisement budget limits prevent us from sending the advertisement to everybody in the network. Therefore, a wise selection of the people can be beneficial in increasing the product adoption. To model these social …

Frequency Selective Detection Of Infrared Radiation In Uncooled Optical Nano-Antenna Array, Sushrut Modak

Electronic Theses and Dissertations

Mid-infrared (mid-IR) detection and imaging over atmospheric transparent 3-5 μm and 8-12 μm bands are increasingly becoming important for various space, defense and civilian applications. Various kinds of microbolometers offer uncooled detection of IR radiation. However, broadband absorption of microbolometers makes them less sensitive to spectrally resolved detection of infrared radiation and the fabrication is also very tedious involving multiple complex lithography steps. In this study, we designed an optical nano-antenna array based detector with narrow frequency band of operation. The structure consists of a two-element antenna array comprised of a perforated metallic hole array coupled with an underneath disk …

Self-Heating Control Of Edge Emitting And Vertical Cavity Surface Emitting Lasers, Yu Zhang

Electronic Theses and Dissertations

Self-heating leads to temperature rise of laser diode and limits the output power, efficiency and modulation bandwidth due to increased loss and decreased differential gain. The main heat sources in laser diode during continuous wave operation are Joule heating and free carrier absorption loss. To control device self-heating, the epi structure needs to be designed with low electrical resistance and low absorption loss, while the heat flux must spread out of the device efficiently. This dissertation presents the control of self-heating of both edge emitting laser diodes and vertical cavity surface emitting lasers (VCSELs). For the 980nm high power edge …

Distribution Of Laser Induced Heating In Multi-Component Chalcogenide Glass And Its Associated Effects, Laura Sisken

Electronic Theses and Dissertations

Chalcogenide glasses are well known to have good transparency into the infrared spectrum. These glasses though tend to have low thresholds as compared to oxide glasses for photo-induced changes and thermally-induced changes. Material modification such as photo-induced darkening, bleaching, refractive index change, densification or expansion, ablation of crystallization have been demonstrated, and are typically induced by a thermal furnace-based heat treatment, an optical source such as a laser, or a combination of photo-thermal interactions. Solely employing laser-based heating has an advantage over a furnace, since one has the potential to be able to spatially modify the materials properties with much …

Highly-Sensitive Stoichiometric Analysis Of Yag Ceramics Using Laser-Induced Breakdown Spectroscopy (Libs), Jahromi, Ali Kazemi

Electronic Theses and Dissertations

Transparent ceramics are an important class of optical materials with applications in high-strength windows, radiation detectors and high-power lasers. Despite the many successful developments of the past decades, their challenging fabrication still needs to be perfected to achieve a better consistency in optical quality. In particular, ternary phase materials such as Yttrium Aluminum Garnet (YAG, Y3Al5O12), a long standing high-power laser host, require a precise control of stoichiometry, often beyond the precision of current analytical techniques, in order to reduce scattering losses and the presence of deleterious point defects. This work explores the potential of Laser-Induced Breakdown Spectroscopy (LIBS) for …