Engineering Commons^™

Design And Implementation Of A High Temperature Fully-Integrated Bcd-On-Soi Under Voltage Lock Out Circuit, Nora Dianne Bull

Masters Theses

As concern about the environment has grown in recent years, alternatives in the automotive industry have become an important topic for researchers. One alternative being considered is electric vehicles, which utilize electric motors. DC/AC inverters and DC/DC power converters control these electric motors. A logic circuit is needed to power these converters; however, the logic generators inherently operate at a voltage too low to power the motors. A device known as the gate driver is the interface between the logic generators (or microcontroller) and the power devices (power converter). The gate driver provides the power needed to drive the power …

Design Of A Highly Constrained Test System For A 12-Bit, 16-Channel Wilkinson Adc, Zachary William Pannell

Masters Theses

Outer space is a very harsh environment that can cause electronics to not operate as they were originally intended. Aside from the extreme amount of radiation found in space, temperatures can also change very dramatically in a relatively small time frame. In order to test electronics that will be used in this environment, they first need to be tested on Earth under replicated conditions. Vanderbilt University designed a dewar that allows devices to be tested at these extreme temperatures while being radiated. For this thesis, a test setup that met all of the dewar's constraints was designed that would allow …

A Gpu-Based Implementation For Improved Online Rebinning Performance In Clinical 3-D Pet, Dilip Reddy Patlolla

Masters Theses

Online rebinning is an important and well-established technique for reducing the time required to process Positron Emission Tomography data. However, the need for efficient data processing in a clinical setting is growing rapidly and is beginning to exceed the capability of traditional online processing methods. High-count rate applications such as Rubidium 3-D PET studies can easily saturate current online rebinning technology. Realtime processing at these high-count rates is essential to avoid significant data loss. In addition, the emergence of time-of-flight (TOF) scanners is producing very large data sets for processing. TOF applications require efficient online Rebinning methods so as to …

Plume Source Localization And Boundary Prediction, Samir Sahyoun

Masters Theses

Plume location and prediction using mobile sensors is the main contribution of this thesis. Plume concentration values measured by chemical sensors at different locations are used to estimate the source of the plume. This is achieved by employing a stochastic approximation technique to localize the source and compare its performance to the nonlinear least squares method. The source location is then used as the initial estimate for the boundary tracking problem. Sensor measurements are used to estimate the parameters and the states of the state space model of the dynamics of the plume boundary. The predicted locations are the reference …

Compressive Sensing Using Random Demodulation, Benjamin Scott Boggess

Masters Theses

The new theory of Compressive Sensing allows wideband signals to be sampled at a rate much closer to the information contained within. This rate is much lower than the Nyquist rate required by Shannon’s sampling theory. This “Analog to Information Conversion” has allowed an outlet for already overloaded Analog to Digital converters [15]. Although the locations of frequencies can’t be known a priori, the expected sparseness of a signal can be. This is the circumstance that allows this method to be possible.

In order to accomplish this very low rate, there is some trade off in sampling rate reduction to …

Emi Chip-To-Tem Cell Coupling For A Microcontroller And Emi Coupling Resulting From Via Transition And Reference Plane Change, Hemant Bishnoi

Masters Theses

"The work presented in this thesis can be broadly categorized under two main headings, estimation of electromagnetic interference (EMI) performance and characterization of EMI performance.

A numerical model of capacitive coupling between two orthogonally crossing double stripline was developed earlier by Kenji Araki and Yoshio Kami at the University of Electro-Communications, Japan. Their model was shown to be accurate up to 3GHz. A verification of their numerical model with full wave simulations is presented here.

In another work done by Shaohua Li, dynamic currents in the power pins of a microcontroller were predicted by using an IC model. The ultimate …

Fault Detection And Prediction With Application To Rotating Machinery, Gary R. Halligan

Masters Theses

"In this thesis, the detection and prediction of faults in rotating machinery is undertaken and presented in two papers. In the first paper, Principal Component Analysis (PCA), a well known data-driven dimension reduction technique, is applied to data for normal operation and four fault conditions from a one-half horsepower centrifugal water pump. Fault isolation in this scheme is done by observing the location of the data points in the Principal Component domain, and the time to failure (TTF) is calculated by applying statistical regression on the resulting PC scores. The application of the proposed scheme demonstrated that PCA was able …

Control Aspects Of A Double-Input Buckboost Power Electronic Converter, Deepak Somayajula

Masters Theses

"Systems in which two or more energy sources combine to supply power to a common load are called hybrid energy systems. Applications of these systems have grown due to their flexibility and reliability. Hybrid energy systems have been successfully implemented in hybrid electric vehicles and wind-solar systems where two or more energy sources share the same load. Double-input (DI) dc-dc power electronic converters (DIPECs) have been gaining popularity in hybrid energy systems due to their reduced component count and control simplicity. In addition, employing DIPECs increases the reliability, stability, and flexibility of the system. In this thesis, a small-signal model …

Automatic Detection Of White Areas In Dermoscopy Images, Ankur Dilip Dalal

Masters Theses

"This thesis presents an algorithm for automatically segmenting the white areas in dermoscopy images. The algorithm includes preprocessing of images, plotting the histogram (RGB) and calculating the average and standard deviation values (RGB) of the lesion. A threshold value for each color plane is determined using these parameters and white areas are automatically segmented. Various image features such as decile percentages and globule features are extracted and given to a neural network. The proposed algorithm has produced a maximum diagnostic accuracy of 94.67% and, when the lesions which touch the image border are removed from the set, the diagnostic accuracy …

Zigbee-Enabled Structural Health Monitoring Using The Smartbrick System, Tyler Harms

Masters Theses

"This thesis describes the design, testing, and proposed extended field test of a wireless sensor network based on the SmartBrick, a structural health monitoring (SHM) device developed at Missouri S&T. The SmartBrick serves as the base station for the network, which utilizes additional sensor nodes to monitor the structure. Each node measures a range of environmental and structural phenomena, including vibration, tilt, humidity, and strain. The nodes use Zigbee short-range communication to transmit their data to the base station, which in turn uses the GSM cellular network to provide long-range communication capability and support for remote control.

Unlike many SHM …

Maximum Likelihood Fusion For Detection Of Led Precursors Using Laser-Induced Breakdown Spectroscopy, Pratik Shah

Masters Theses

"Improvised Explosive Devices (IEDs) pose an increasing threat to the safety of soldiers and civilians in embattled areas. The use of compounds such as RDX complicates the detection of IEDs, as these compounds are often hard to identify in the presence of contaminants such as alcohol, oils and dust. Spectroscopic techniques such as Laser-Induced Breakdown Spectroscopy (LIBS) and Raman have shown promise for the detection of explosive compounds; however, their accuracy is limited, as noise can cause variations in the peak strengths and locations that they utilize for classification.

The research presented in this thesis applies signal processing to the …

Analysis Of Lesion Border Segmentation Using Watershed Algorithm, Hanzheng Wang

Masters Theses

"Automatic lesion segmentation is an important part of computer-based skin cancer detection. A watershed algorithm was introduced and tested on benign and melanoma images. The average of three dermatologists' manually drawn borders was compared as the benchmark. Hair removing, black border removing and vignette removing methods were introduced in preprocessing steps. A new lesion ratio estimate was added to the merging method, which was determined by the outer bounding box ratio. In postprocessing, small blob removing and border smoothing using a peninsula removing method as well as a second order B-Spline smoothing method were included. A novel threshold was developed …

Vehicle Positioning Using Image Processing, Armadeep Kaur

Masters Theses

"An imaging-processing approach is described that detects the position of a vehicle on a bridge or similar environment. A load-bearing vehicle must be carefully positioned on a bridge for quantitative bridge monitoring. The personnel required for setup and testing and the time required for bridge closure or traffic control are important management and cost considerations. Consequently, bridge monitoring and inspections are good candidates for smart embedded systems. The objectives of this work are to reduce the need for personnel time and to minimize the time for bridge closure. An approach is proposed that uses a passive target on the bridge …

The Assessment Of Winding Forces Due To Inrush Current In Large Transformers With Heavily Saturated Cores, Richard Howard Palmer

Masters Theses

"It has been suspected that certain high voltage generator step-up transformers due to large inrush current occurring when the transformers were connected to the energized transmission lines but the generators were not operating. Even though the transformers are designed to withstand the winding forces developed under short circuit conditions, the transformers failed when energized. Therefore, to gain further insight into this phenomenon, this research was undertaken. The research evaluates and compares the relative magnitude of the winding forces produced under inrush and short circuit current conditions in transformers of different design and winding configurations"--Abstract, page iv.

Localization Of Nodes In Wired And Wireless Networks, Hindu Kothapalli

Masters Theses

"This thesis focuses on the implementation of algorithms for localization of nodes in wired and wireless networks. The thesis is organized into two papers. The first paper presents the localization algorithms based on time of arrival (TOA) and time difference of arrival (TDOA) techniques for computer networks such as the Internet by using round-trip-time (RTT) measurements obtained from known positions of the gateway nodes. The RTT values provide an approximate measure of distance between the gateway nodes and an unknown node. The least squares technique is then used to obtain an estimated position of the unknown node. The second paper …

Modeling Of Vias And Via Arrays In High Speed Printed Circuit Boards, Arun Reddy Chada

Masters Theses

"This thesis presents modeling approaches for fast calculation of signals in dense via arrays in high speed printed circuit boards (PCBs) and model to hardware correlation study of solid and perforated disk resonators. A 2D finite difference (FD) method to extract the via capacitance which includes the via pad capacitance obtained by solving the laplace equation in the via domain in multi-layer geometries is presented and validated with analytical formulation for via capacitance. Next, closed-form expression for the impedance of an infinitely large parallel plane pair is derived and validated by comparing with cavity model for several numerical examples. The …

Numerical Modeling And Analysis Of Complex Electromagnetic Structures, Including Those Containing Ferrites, Andrea Orlando

Masters Theses

"Application of fast switching amplifiers in power converters, and especially in power inverters, causes unwanted radiated emission, which is a consequence of common mode (CM) currents arising in feed wire bundles. Ferrite chokes are commonly used to suppress those CM currents by increasing the CM impedance of circuits without affecting the differential mode currents, which is important for undisturbed operation of the converters or inverters. Their effective impedance is the main design concern, and it is determined by the material intrinsic properties (permeability, permittivity) and geometry. The goal of this work is to analytically correlate the geometrical and material properties …

Real-Time Reconfiguration Of Programmable Logic Controller Communication Paths, Curtis Alan Parrott

Masters Theses

"This thesis explores the topics related to reconfiguration of Programmable Logic Controller's (PLC's) communications paths as it relates to network security and reliability. These paths are normally fixed, which creates a single fault point which can easily be disrupted by network failure or network based attack. With the ability for autonomous communications path reconfiguration these disruptions in communications can be avoided or bypassed. This work builds on these principles and a series of PLC programs are developed to facilitate several things: Scanning of the three different network types most common in PLC to PLC communications; a comprehensive network scan routine …

Inductance Modeling And Extraction In Emc Applications, Clint Matthew Patton

Masters Theses

"Inductance has become a challenging problem for EMC engineers in many applications. Regardless of the application at hand, the first step remains the same; return to the physics and trace the current paths. IGBTs have become an important part in the design of power electronics because of their ability to switch fast and with stand high currents. Modules used for three phase motor drives often create problems when neglected parasitic components show themselves and interfere with the performance of the desired operation of a system. Many manufactures of these modules do not give out equivalent circuit modules and therefore leave …

The Development And Application Of The Complete Time-Domain Trl Calibration Technique, Hongxia Ning

Masters Theses

"The first paper in the thesis discussed the development of a complete time-domain THRU-REFLECT-LINE (t-TRL) calibration technique. To validate the error correction technique, two stripline TRL test fixtures are designed and measured by two TDR instruments respectively. The t-TRL calibration is implemented to the recorded TDR/TDT waveforms and the comparison of the magnitude and phase results of S-parameters obtained by t-TRL and VNA TRL shows excellent agreement up to 25GHz.

In the second paper, the application of t-TRL calibration technique to the Root Impulse Energy (RIE) loss calculation is discussed. The RIE loss is theoretically derived for the matched network …

Spectral And Spatial Analysis Of False Alarms In Airborne Minefield Data, Abhishek Sanaka

Masters Theses

"Tests run in May 2005 at an arid site as part of airborne minefield detection yielded substantial airborne background data with ground truthed and surveyed false alarm locations. ERDC and MultiSensor LLC identified the locations, geo referenced and documented different false alarms. The project reported here built a self-contained database of image chips recording target signatures for MSI (four bands) and MWIR sensors for false alarms from this background data and mines from related areas. The image chips represent various days, times of day, altitudes, as well as several different sources of false alarm and mine types. The database facilitates …

Depth Evaluation Of Damage To Aircraft Fuselage Skins Using Microwave And Millimeter Wave Methods, Andrew Dale Mcclanahan

Masters Theses

"The depth of damage to metal surfaces is a particularly useful, sought after, and difficult to obtain piece of information, and is used to guide repair decisions. For this investigation such damage is represented as rectangular slots (cracks) or cylindrical pits. Several millimeter wave methods are presented to evaluate depth. The quarter-wavelength resonant response of cracks, excited by a probing rectangular waveguide, allows evaluation of depth using the phase of reflection coefficient. A theoretical derivation is also supplied, modeling the system as the junction of two rectangular waveguides, the probing waveguide and the crack. If the crack is filled with …