Engineering Commons^™

On The Development Of Conductive Textile Antennas, Dounia Baiya

Masters Theses

UWB systems are becoming increasingly utilized due to their use in a variety of applications. Meanwhile, many advances have been achieved in the realm of conductive textiles. These textiles can be used as a sensing system or implemented wearable antennas. Combining these two applications is attractive for a number of reasons. First, wearable antennas constructed entirely from fabric offer a cost- effective, flexible solution when compared to rigid antennas. Second UWB technology is also attractive for body area network applications due to the low power operation and the inherent low radiated power in its system design.

In our implementation accurately …

A New Approach To Optimization Of Dynamic Reactive Power Sources Addressing Fidvr Issues, Weihong Huang

Masters Theses

Dynamic reactive power (var) sources, e.g. SVCs and STATCOMs, can effectively mitigate fault-induced delayed voltage recovery (FIDVR) issues or even voltage collapse. However, their optimal allocation in a power grid is a complicated nonlinear optimization problem since the post-fault voltage trajectories have to be solved to check constraints on voltage responses. Thus, solvers of both nonlinear optimization and power system differential and algebraic equations (DAEs) are required.

Currently, most of existing methods merely achieve dynamic optimization locally with great dependence on the initial operation point. Also, complicated algorithm and time consuming are obstacles for the practical implementation.

This thesis proposes …

Direct Torque Control Of An Lnduction Machine Using Multi-Layer Perceptron Network, Adithya Chandrashekharan

Masters Theses

In conventional direct torque control (DTC) scheme of induction motor (lM), Proportional Integral Controller (PI) is used as the speed controller. PI controller is more suitable in steady state condition and for linear system but both DTC and IM are mostly nonlinear. Multi-Layer perceptron neural network. (MLPNN) controller is more suitable and performs better than PI controller. The switching table of the conventional DTC is replaced by the MLPNN controller. The MLPNN inputs are, the magnitude of the stator flux, torque and the Voltage sectors. Levenberg-Marquardt back propagation technique has been used to train the MLPNN. The output of the …

An Autonomous Online I-V Tracer For Pv Monitoring Applications, Cameron William Riley

Masters Theses

With the unprecedented growth of photovoltaic technologies and their implementation in recent times, more precise methods of determining modules health, degradation, and performance are needed. Current monitoring efforts are helpful in determining these attributes but do not provide all of the information necessary to truly understand the health properties of the PV module in question. The current-voltage curve, or I-V curve, provides a level of insight into a PV module’s health unparalleled by most monitoring efforts. However, the tools which measure the I-V curve exist in an undesirable form—PV must be disconnected from its load and connected to the tool …

A Low-Power Approach For Front End Biological Signal Conditioning, Logan Smith Taylor

Masters Theses

In a lab-on-a-chip (LOC) application, the measurement of small analog signals such as local temperature variation often involves detection of very low-level signals in a noisy micro-scale environment. This is true for other biomedical monitoring systems as well. These systems observe various physiological parameters or electrochemical reactions that need to be tracked electrically. For temperature measurement pyroelectric transducers represent an efficient solution in terms of speed, sensitivity, and scale of integration, especially when prompt and accurate temperature monitoring is desired.

The ability to perform laboratory operations on a small scale using miniaturized LOC devices is a promising biosensing technique. The …

Novel Method For Broadband On-Chip Noise Characterization, Mohammad Ghadiri Sadrabadi

Masters Theses

A novel method for on-chip noise characterization of mm-wave circuits is presented. Different available methods for noise measurements and requirements for on-chip noise mea-surements are studied. The Y-factor method is chosen to be the more suitable method for in-situ applications since it does not require absolute measurements. A state of the art CMOS noise source is implemented in 32nm SOI CMOS technology to enable the in-situ noise measurements of a 20-35 GHz reconfigurable low noise amplifier. Measurement results show that the ENR of the noise source is repeatable enough so that the calibration of the noise source is only required …

Propagation Prediction Over Random Rough Surface By Zeroth Order Induced Current Density, Narayana Srinivasan Balu

Masters Theses

Electromagnetic wave propagation over random sea surfaces is a classical problem of interest for the Navy, and significant research has been done over the years. Here we make use of numerical and analytical methods to predict the propagation of microwaves over random rough surface. The numerical approach involves utilization of the direct solution (using Volterra integral equation of the second kind) to currents induced on a rough surface due to forward propagating waves to compute the scattered field. The mean scattered field is computed using the Monte-Carlo method. Since the exact solution (consisting of an infinite series) to induced current …

Impedance Measurement Of Small Antennas Over A Ground Plane Without Direct Cable Attachment, Yutong Yang

Masters Theses

An indirect impedance measurement approach that does not require direct cable attachment or large space using a two-port network is presented. Using a straight wire monopole as an interrogating antenna and measured impedances of three calibration standards, the input impedance of a small spherical helix dipole over a ground plane is retrieved. It is found that accurate result is obtained around the dipole resonance frequency. The accuracy and sources of error are discussed.

Design And Implementation Of A Network Service Marketplace, Yunsheng Qi

Masters Theses

The Internet has successfully served the world for more than three decades, while limitations and drawbacks still exist. A lot of researches have been done on innovation of Internet to address those inadequacies. One approach to improve Internet performance is to make choice as a principle in network architecture. We believe that a service-based network architecture with choice, or we call it ChoiceNet, is the most suitable option for future Internet. In this thesis, we design and implement a network service marketplace. Due to the flexibility and functionality of web application, the marketplace is implemented by a web application to …

Effect Of Clock And Power Gating On Power Distribution Network Noise In 2d And 3d Integrated Circuits, Vinay C. Patil

Masters Theses

In this work, power supply noise contribution, at a particular node on the power grid, from clock/power gated blocks is maximized at particular time and the synthetic gating patterns of the blocks that result in the maximum noise is obtained for the interval 0 to target time. We utilize wavelet based analysis as wavelets are a natural way of characterizing the time-frequency behavior of the power grid. The gating patterns for the blocks and the maximum supply noise at the Point of Interest at the specified target time obtained via a Linear Programming (LP) formulation (clock gating) and Genetic Algorithm …

Ubot-7: The Design Of A Compliant Dexterous Mobile Manipulator, Jonathan Cummings

Masters Theses

This thesis presents the design of uBot-7, the latest version of a dexterous mobile manipulator. This platform has been iteratively developed to realize a high performance-to-cost dexterous whole body manipulator with respect to mobile manipulation. The semi-anthropomorphic design of the uBot is a demonstrated and functional research platform for developing advanced autonomous perception, manipulation, and mobility tasks. The goal of this work is to improve the uBot’s ability to sense and interact with its environment in order to increase the platforms capability to operate dexterously, through the incorporation of joint torque feedback, and safely, through the implementation of passive and …

Design Of Non-Uniform Linear Array Via Linear Programming And Particle Swarm Optimization And Studies On Phased Array Calibration, Hua Bai

Masters Theses

For a linear array, the excitation coefficients of each element and its geometry play an important role, because they will determine the radiation pattern of the given array. Side Lobe Level (SLL) is one of the key parameters to evaluate the radiation pattern of the array. Generally speaking, we desire SLL to be as low as possible. For the linear array with uniform spacing, there are some classic methods to calculate the excitation coefficients to make the radiation pattern satisfy the given requirements. For the linear array with non-uniform spacing, linear programming and particle swarm optimization are proposed to calculate …

Millimeter Wave Indium Phosphide Heterojunction Bipolar Transistors: Noise Performance And Circuit Applications, Metin Ayata

Masters Theses

The performance of III-V heterojunction bipolar transistors (HBTs) has improved significantly over the past two decades. Today’s state of the art Indium Phosphide (InP) HBTs have a maximum frequency of oscillation greater than 800 GHz and have been used to realize an amplifier operating above 600 GHz . In comparison to silicon (Si) based devices, III-V HBTs have superior transport properties that enables a higher gain, higher speed, and noise performance, and much higher Johnson figure- of-merit . From this perspective, the InP HBT is one of the most promising candidates for high performance mixed signal electronic systems.

Design And Evaluation Of An L-Band Current-Mode Class-D Power Amplifier Integrated Circuit, Michael J. Shusta

Masters Theses

Power amplifiers (PAs) convert energy from DC to high frequencies in all radio and microwave transmitter systems be they wireless base stations, handsets, radars, heaters, and so on. PAs are the dominant consumers of energy in these systems and, therefore, the dominant sources of system cost and inefficiency. Research has focused on efficient solid-state PA circuit topologies and their optimization since the 1960s. The 2000s saw the current-mode class-D (CMCD) topology, potentially suitable for today's wireless communications systems, show promise in the UHF frequency band. This thesis describes the design and testing of a high-efficiency CMCD amplifier with an integrated …

Statistical Analysis Of Disturbances In Power Transmission Systems, Liu Liu

Masters Theses

Disturbance analysis is essential to the study of the power transmission systems. Traditionally, disturbances are described as megawatt (MW) events, but the access to data is inefficient due to the slow installation and authorization process of the monitoring device. In this paper, we propose a novel approach to disturbance analysis conducted at the distribution level by exploiting the frequency recordings from Frequency Disturbance Recorders (FDRs) of the Frequency Monitoring Network (FNET/GridEye), based on the relationship between frequency change and the power loss of disturbances - linearly associated by the Frequency Response. We first analyze the real disturbance records of North …

Digital-To-Analog Converter Interface For Computer Assisted Biologically Inspired Systems, Nicholas Conley Poore

Masters Theses

In today's integrated circuit technology, system interfaces play an important role of enabling fast, reliable data communications. A key feature of this work is the exploration and development of ultra-low power data converters. Data converters are present in some form in almost all mixed-signal systems; in particular, digital-to-analog converters present the opportunity for digitally controlled analog signal sources. Such signal sources are used in a variety of applications such as neuromorphic systems and analog signal processing. Multi-dimensional systems, such as biologically inspired neuromorphic systems, require vectors of analog signals. To use a microprocessor to control these analog systems, we must …

Improved Accuracy In Real-Time Rfid Localization Systems Using Kalman Filtering, Benjamin J. Sanda

Masters Theses

The use of Radio Frequency Identification (RFID) has become widespread in industry as a means to quickly and wirelessly identify and track packages and equipment. Now there is a commercial interest in using RFID to provide real-time localization. Efforts to use RFID technology for this purpose experience localization errors due to noise and multipath effects inherent to these environments. This paper presents the use of both linear Kalman filters and non-linear Unscented Kalman filters to reduce error effects inherent to real-time RFID localization systems and provide more accurate localization results in indoor environments. A commercial RFID localization system designed for …

Hardware-In-Loop Evaluation Of Microgrid Protection Schemes, Kevin Michael Dowling

Masters Theses

Distributed energy resources are becoming more common in distribution systems. Higher energy prices and increased interest in alternative energy sources are two of the driving forces behind this trend. Local utilities, however, anticipate very serious distribution system protection problems resulting from high penetration of these resources.

The microgrid concept has been proposed as a possible solution to integrating distributed energy resources without adversely impacting the distribution system. Protection schemes have been proposed to work within this microgrid structure, but very little testing with real hardware is available. Without a practical solution for microgrid protection, backed by extensive studies, microgrids are …

A Novel Authentication Method Using Multi-Factor Eye Gaze, Lucas A. Herrera

Masters Theses

A method for novel, rapid and robust one-step multi-factor authentication of a user is presented, employing multi-factor eye gaze. The mobile environment presents challenges that render the conventional password model obsolete. The primary goal is to offer an authentication method that competitively replaces the password, while offering improved security and usability. This method and apparatus combine the smooth operation of biometric authentication with the protection of knowledge based authentication to robustly authenticate a user and secure information on a mobile device in a manner that is easily used and requires no external hardware. This work demonstrates a solution comprised of …

Microgrid Modeling And Grid Interconnection Studies, Hira Amna Saleem

Masters Theses

The demand for renewable energies and their integration to the grid has become more pressing than ever before due to the various reasons including increasing population energy demand, depleting fossil fuels, increasing atmospheric population, etc. Thus the vision of a sustainable future requires easy and reliable integration of renewable distributed generators to the grid. This master’s thesis studies the dynamics of distributed generators when they are connected with the main grid. Simulink MATLAB is used for the design and simulations of this system. Three distributed generators are used in this system: Photo-voltaic converter, Fuel cell and diesel generator. The control …

Low Pressure Chemical Vapor Deposition Of Semiconducting Boron Carbide Thin Films On Silicon, Thomas Gregory Wulz

Masters Theses

Boron carbide thin films were grown on the (100) plane of n-type silicon in a low pressure chemical vapor deposition (CVD) system from the thermal decomposition of boron trichloride and methane reactant gases with hydrogen as a carrier gas. Boron trichloride to methane molar ratio was 5, while the boron trichloride to hydrogen molar ratio was 3.5. Thin film deposition was carried out at 900 degrees Celsius at 25 Torr. The thin films were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDS), Laser Induced Breakdown Spectroscopy (LIBS), and current-voltage characteristics. The crystallography of …

Improved Forensic Medical Device Security Through Eating Detection, Nathan Lee Henry

Masters Theses

Patients are increasingly reliant on implantable medical device systems today. For patients with diabetes, an implantable insulin pump system or artificial pancreas can greatly improve quality of life. As with any device, these devices can and do suffer from software and hardware issues, often reported as a safety event. For a forensic investigator, a safety event is indistinguishable from a potential security event. In this thesis, we show a new sensor system that can be transparently integrated into existing and future electronic diabetes therapy systems while providing additional forensic data to help distinguish between safety and security events. We demonstrate …

Development Of A Testing Platform For Secondary-Use Electric Vehicle Batteries As Community Energy Storage Systems, Thomas Benjamin Ollis

Masters Theses

Energy storage is quickly transforming from a commodity to a necessity for electric utilities. The peak demand on the electric grid continues to grow, requiring more sources of generation and upgrades to infrastructure. The variability of renewable generation sources, such as wind and solar, has created more uncertainty on the generation side of the electric grid. Energy storage represents one possible solution to mitigate the demand and uncertainty; however, energy storage systems have historically been too expensive to recoup their capital cost. More recently, research into electric vehicle batteries has brought their cost down and improved performance. As they continue …

Optimal Control Of Energy Efficient Buildings, Cale David Nelson

Masters Theses

The building sector consumes a large part of the energy used in the United States and is responsible for nearly 40% of greenhouse gas emissions. Therefore, it is economically and environmentally important to reduce the building energy consumption to realize massive energy savings. Commercial buildings are complex, multi-physics, and highly stochastic dynamic systems. Recent work has focused on integrating modern modeling, simulation, and control techniques to solving this challenging problem. The overall focus of this thesis is directed toward designing an energy efficient building by controlling room temperature. One approach is based on a distributed parameter model represented by a …

Analysis And Modeling Of Resilience For Networked Systems, Kamlesh Ashok Joshi

Masters Theses

"A cyber physical system (CPS) has two main subsystems; a physical infrastructure that is responsible for managing and implementing physical tasks, e.g., generation and distribution of a physical commodity, and a cyber infrastructure that is used to support and enhance these physical operations through computing, communication, and control. Imperfect cyber control can lower the efficacy and even reliability of existing physical infrastructures. As such, justifiable reliance on CPSs requires rigorous investigation of the effect of incorporating cyber infrastructure on functional and non-functional aspects of system performance. One non-functional metric of note is resilience, defined as the ability of a system …

Application Of Electrically Invisible Antennas To The Modulated Scatterer Technique, Dylan Andrew Crocker

Masters Theses

"The Modulated Scatterer Technique (MST) has shown promise for applications in microwave imaging, electric field mapping, and materials characterization. Traditionally, MST scatterers consist of dipole antennas centrally loaded with a lumped element capable of modulation (commonly a PIN diode). By modulating the load element, the signal scattered from the MST scatterer is also modulated. However, due to the small size of such scatterers, it can be difficult to reliably detect the modulated signal. Increasing the modulation depth (a parameter related to how well the scatterer modulates the scattered signal) may improve the detectability of the scattered signal. In an effort …

Cable Discharge Events (Cde) -- A Modeling And Simulation Perspective, Viswa Pilla

Masters Theses

"Cable discharge events (CDE) typically occur when a charged cable is connected to an electronic device. Several CDE damages in Ethernet LAN and USB communication interface equipment are reported by the IC manufacturers. CDE differs from other types of ESD such as human body model (HBM), charged device model (CDM) and IEC 61000-4-2 mainly due to faster rise times, longer pulse widths and higher peak currents. Various factors such as cable geometries, charging and discharging mechanisms, and load conditions influence CDE. Several researchers have developed some measurement techniques to understand CDE waveforms. However, there is little information regarding its modeling …

Improved Phase Shedding Technique In A Multiphase Converter System, Anagha Rayachoti

Masters Theses

"Multiphase converters are increasingly gaining prominence in the field of power electronics. The main advantage of a multiphase converter is its increased efficiency in comparison to a single phase converter. The one major drawback of a multiphase converter is its light load efficiency. Light load efficiency in multiphase converters is very poor when compared to single phase converters. Phase shedding is one of the approaches used to improve this light load efficiency but the transient output voltage response of the system shows large deviations during the process of phase change. This thesis proposes a new technique, called the ramp control …

Design And Implementation Of Two Non-Isolated High Gain Dc-Dc Converters, Huawei Yang

Masters Theses

"In most solar energy systems, the output voltage of a photovoltaic panel is usually between 20 to 40 Vdc. In order to interface the panels to a 400 Vdc bus, a high voltage gain dc-dc converter is required.

This thesis starts with analyzing and simulating several topologies that have been already introduced for this application. The voltage gain and efficiency are investigated analytically. A hardware prototype of one of the existing topologies, the interleaved boost converter with voltage multiplier cell, has been developed. Finally, a new topology with a higher voltage transfer ratio is proposed and its experimental results are …

Analysis Of Factors Responsible For Life Degradation Of Led Traffic Indicators In The State Of Missouri, Snehal Satish Digraskar

Masters Theses

"Traffic lights using state-of-the-art LED illumination use 90 percent less electricity and offer a much longer service life and durability than their incandescent counterparts. Taking advantage of the countless benefits, cities around the country have been replacing traditional filament-based traffic signal bulbs with LEDs for years. However, the degradation of LEDs and hence the replacement strategy, are a concern which is faced by most of the Departments of Transportation. The thesis work sponsored by MoDOT, presents the replacement strategy developed based on the field study of LED indicators in Missouri. Three types of analysis are performed with multiple data point …