Engineering Commons^™

Improving Life Cycle Management Plans For Power Plant Components, Srinath Raghavan

Masters Theses

"Life cycle management (LCM) combines a set of technical and economic activities with the specific goal of improving the long term economic value of an asset. It is necessary to perform a sound LCM exercise on the utility or industrial asset to maintain the profitability of a plant. In most industries, the maintenance budget is either higher than optimal or lower than required, that result in expensive outages, damages and accidents. An LCM plan is a guide to make operational decision for a component over its life cycle. LCM typically consists of a preventive maintenance schedule, condition monitoring, inspection activities, …

Harmonic Compensation In A Grid Using Doubly Fed Induction Generators, Omkar Amol Ghatpande

Masters Theses

"Ideally, electric utilities are expected to deliver a sinusoidal voltage with a constant rated frequency, while customers are expected to draw a sinusoidal current with unity power factor. The recent widespread use of harmonic producing equipment in industrial applications, especially non-linear loads, has increased the distortion of electric currents and voltages in transmission and distribution systems. This thesis proposes a method of using multiple reference frame theory for measuring and mitigating harmonic currents of nonlinear loads using a doubly fed induction generator. The most significant low-order harmonics to be compensated are calculated using a multiple reference frame harmonic observer. This …

Systems And Image Database Resources For Uav Search And Rescue Applications, David Christopher Macke Jr.

Masters Theses

"Aerial search and rescue applications using unmanned aerial vehicles (UAVs) can incorporate image processing technologies to locate targets faster and with a higher degree of accuracy. The task of developing such systems involves the development of both hardware and software components. Examples of both hardware and software approaches in the design process for an aerial imaging system are shown for small UAV applications. This project contains resources to help facilitate the incorporation of UAV applications into educational ventures and design projects. A power supply design is done for a lightweight imaging system and a large database of aerial images is …

Direct - Drive Permanent Magnet Synchronous Generator Design For Hydrokinetic Energy Extraction, Amshumaan Raghunatha Kashyap

Masters Theses

"Hydrokinetic turbines deliver lower shaft speeds when compared to both steam and wind turbines. Hence, a water wheel generator must operate at speeds as low as 150 - 600 rpm. This thesis describes a permanent magnet synchronous generator (PMSG) that was designed, built, and tested to serve a low speed hydrokinetic turbine. The design methodology was emphasized since designing an application specific generator poses various design and hardware construction issues. These are torque, speed, power and start-up requirements. This generator was built to operate without a speed increaser, implying very low speeds. FEA and performance results from the simulation done …

A Calibration Free Vector Network Analyzer, Arpit Kothari

Masters Theses

"Recently, two novel single-port, phase-shifter based vector network analyzer (VNA) systems were developed and tested at X-band (8.2 - 12.4 GHz) and Ka-band (26.4 - 40 GHz), respectively. These systems operate based on electronically moving the standing wave pattern, set up in a waveguide, over a Schottky detector and sample the standing wave voltage for several phase shift values. Once this system is fully characterized, all parameters in the system become known and hence theoretically, no other correction (or calibration) should be required to obtain the reflection coefficient, (Γ), of an unknown load. This makes this type of VNA "calibration …

High Temperature Sensor Based On Fabry-Perot Interferometer In Ceramic Coaxial Cable, Kenneth Paul Smith Jr.

Masters Theses

"In this thesis, the application of a coaxial cable Fabry-Perot interferometer (CCFPI) as a high temperature sensor is analyzed. Coaxial cable sensors provide the advantages of fiber optic sensors, such as the ability to be embedded and multiplexed, while overcoming the limitations created by the fragility of fibers. The fabrication process of the CCFPI, using a computer controlled drill system to create holes in the cable is discussed. By analyzing the amplitudes of the created reflections, the diameter of the holes is optimized. A new fabrication process, in which holes are drilled 180⁰ apart from each other to create a …

Feature Extraction Through K-Means Segmentation For Melanoma Detection, Snigdha Priya Bommadevara

Masters Theses

"Malignant melanoma is responsible for 75% of the deaths caused due to skin cancer annually. However, melanoma detection can be possible through feature extraction and pattern classification, which can lower the risk, if the melanoma is detected at an early stage. Clustering is one of the most useful tools used to differentiate features that can contribute to melanoma. This research work uses the k-means clustering algorithm for implementation of color segmentation. However, k-means clustering requires a predefined value of k, i.e., the number of clusters must be specified at the beginning of the run. This research uses a predefined value …

Constructing Conducted Emission Models For Integrated Circuits, Shuai Jin

Masters Theses

"Conducted emissions, noise conducted out of integrated circuit pins, play an important role in determining the system level EMC performance. Characterizing conducted emissions from ICs is investigated and the corresponding noise models are developed in this thesis. Both simulation IBIS and measurement based methods for noise-model construction are studied. The constructed noise source model for a test IC is applied in system-level simulations and the calculated far field radiation is validated with measurements. The agreement in the simulated and measured results demonstrates the effectiveness of the constructed model for characterizing the conducted emissions from an IC I/O pin"--Abstract, page iii.

A Study Of Clustering Rssi And Lqi From Wireless Network Communications, Yanwen Wang

Masters Theses

"In today's information world, different wireless sensor network topologies are permitted to exist in the same geographical region. For example, a city contains thousands of enterprise networks; a school might include different wireless network topologies used by students and faculties respectively. Even within a building, there might be multiple companies that use their own wireless networks. These networks might cause interference to other networks. How to detect, determine and locate the unknown wireless topologies in the same geographical area becomes quite significant in the wireless industry, especially in military use, such as spy-nodes detection and communication orientation systems. In this …

Wideband Characterization Of Printed Circuit Board Materials Up To 50 Ghz, Aleksei Rakov

Masters Theses

"A traveling-wave technique developed a few years ago in the Missouri S&T EMC Laboratory has been employed until now for characterization of PCB materials over a broad frequency range up to 30 GHz. This technique includes measuring S-parameters of the specially designed PCB test vehicles. An extension of the frequency range of printed circuit board laminate dielectric and copper foil characterization is an important problem. In this work, a new PCB test vehicle design for operating up to 50 GHz has been proposed. As the frequency range of measurements increases, the analysis of errors and uncertainties in measuring dielectric properties …

Technical Modeling And Control System Development Of Hybrid Energy System Using Coal, Nuclear, Wind And Diesel, Uday Guntupalli

Masters Theses

"Addressing the growing energy concerns of the modern world is a challenging problem. Traditional carbon intensive fuel sources like coal, diesel which are instrumental in meeting today's grid demand are struggling to meet the stringent environmental regulations. Operations of independent renewable energy sources despite reducing costs are not comparable to existing costs of electricity. A sustainable approach to address these concerns is proposed in this work. A hypothetical hybrid system involving traditional fuel sources like coal, small modular nuclear reactor and renewable energy source wind is analyzed through dynamic modeling using various tools.

Various simulation tools were analyzed and the …

A Conforming Method For Regional Marginal Loss Surplus Allocation, Xiaolong Wang

Masters Theses

"The marginal transmission loss model is used in electricity markets across the United States to measure a resource's marginal contribution to system loss. This model prices loss into the locational marginal price as a marginal loss component. Marginal loss pricing will render a net revenue surplus within an energy balanced system. This marginal loss surplus (MLS) is typically allocated back to scheduling coordinators in proportion to the measured demand on a system-wide basis. However, when the system experiences heterogeneous loss across different regions, the system-wide allocation method fails to recognize the regional differences in actual loss costs. As a result, …

Quantization Noise Analysis Of A Closed-Loop Pwm Controller That Includes Σ-Δ Modulation, Anupama Balakrishnan

Masters Theses

"Σ-Δ modulation is a popular noise shaping technique which is used to move the quantization noise out of the frequency band of interest. Recently, a number of authors have applied this technique to a pulse width modulation (PWM) controller for switching power converters. However, previous analysis has not incorporated the effects of analog-to-digital converter (ADC) resolution or feedback control on the Σ-Δ modulator. In this work, quantization due to ADC resolution and PWM resolution are analyzed, considering the effects of noise-shaping and feedback. A number of simulations have been performed to explore the impact of various design choices on output …

Parallel-Connected Solar Arrays, Majed Meshal Alabbass

Masters Theses

"The purpose of this thesis is to investigate the advantages of having various series-parallel configurations of solar arrays and make a comparison between them. The objective is to determine the best PV system configuration and thus improve the overall efficiency of a solar array. The primary focus of this thesis is to study the parallel connection of PV panels for achieving maximum efficiency while extracting maximum energy from the solar radiation. A comparison between a series connected and a parallel connected solar PV array justifies the need for installing a parallel configured solar PV array to achieve optimum performance. The …

Fabry-Perot Interferometer Based Co₂ Sensor Using Ionic-Liquid, Mujahid Abdul

Masters Theses

"Anthropogenic greenhouse gas emission has become an eminent problem today especially CO₂ gas emission is of major importance. Statistics show that CO₂ concentration is consistently increasing in atmosphere every year. Having cognizance of this problem, better CO₂ absorbents, ionic liquids, has been suggested through this thesis. To prove Ionic liquid's efficiency, a unique sensor was developed by a sophisticated fabrication using Femto-second (fs) laser. Sensor is built to work as an extrinsic Fabry-Perot Interferometer (EFPI) to sense CO₂. EFPI sensor consists of a glass tube fused between two single mode fibers, and a miniature hole is fabricated in the tube …

Design And Analysis Of An Open-Ended Waveguide Probe For Material Characterization, Matthew Alan Kempin

Masters Theses

"Nondestructive evaluation of stratified (layered) composite structures at microwave and millimeter wave frequencies is of great interest in many applications where simultaneous determination of the complex dielectric properties and thicknesses of multiple layers is desired. Open-ended rectangular waveguide probes are effective tools for this purpose. The technique requires a full-wave electromagnetic model that accurately calculates the complex reflection coefficient as a function of frequency and material properties. Subsequently, this information is used in conjunction with the measured complex reflection coefficient to evaluate the sought for material properties. This thesis presents simulated and measured data to investigate the influence that measurement …

New Sensorless, Efficient Optimized And Stabilized V/F Control For Pmsm Machines, Seyed Hesam Jafari

Masters Theses

"With the rapid advances in power electronics and motor drive technologies in recent decades, permanent magnet synchronous machines (PMSM) have found extensive applications in a variety of industrial systems due to its many desirable features such as high power density, high efficiency, and high torque to current ratio, low noise, and robustness. In low dynamic applications like pumps, fans and compressors where the motor speed is nearly constant, usage of a simple control algorithm that can be implemented with least number of the costly external hardware can be highly desirable for industry. In recent published works, for low power PMSMs, …

Fluidic Sensor Devices Utilizing Dry Film Resist As Main Structural Materials, Sijia Gong

Masters Theses

"In this thesis, two types of fluidic sensor devices are demonstrated. The first device utilizes a dry film resist (DFR) as the main structural material of fluidic device utilizing the photolithography process. The second one involves a simple, low-cost sensor platform composed of ubiquitous materials such as polymer tubing and metal wires. Both devices are prepared to measure the dissolved oxygen content, as a model target analyte, based on the oxygen quenching reaction of a ruthenium complex fluorophore as the reporting agent. Characterization of sensors is conducted based on the fluorescence lifetime measurement. The first type of sensor is constructed …

Feature Extraction Through Median-Split Algorithm Segmentation For Melanoma Detection, Venkata Sai Narasimha Kaushik Ghantasala

Masters Theses

""Detection of melanoma remains an empirical clinical science. New tools for automatic discrimination of melanoma from benign lesions in digitized dermoscopy images may allow an improvement in early detection of melanoma. This research implements a fast version of the median split algorithm in an open source format and applied to four-color splitting of the lesion area to capture the architectural disorder apparent in melanoma colors. This version of the median split algorithm splits colors along the color axis with maximum range". For a dermoscopy set of 888 images, K-means clustering algorithm is compared with a median split algorithm to find …