Engineering Commons^™

Integrated Circuit Wear-Out Prediction And Recycling Detection Using Radio-Frequency Distinct Native Attribute Features, Randall D. Deppensmith

Theses and Dissertations

Radio Frequency Distinct Native Attribute (RF-DNA) has shown promise for detecting differences in Integrated Circuits(IC) using features extracted from a devices Unintentional Radio Emissions (URE). This ability of RF-DNA relies upon process variation imparted to a semiconductor device during manufacturing. However, internal components in modern ICs electronically age and wear out over their operational lifetime. RF-DNA techniques are adopted from prior work and applied to MSP430 URE to address the following research goals: 1) Does device wear-out impact RF-DNA device discriminability?, 2) Can device age be continuously estimated by monitoring changes in RF-DNA features?, and 3) Can device age state …

Improvements To Micro-Contact Performance And Reliability, Tod V. Laurvick

Theses and Dissertations

Microelectromechanical Systems (MEMS) based devices, and specifically microswitches, continue to offer many advantages over competing technologies. To realize the benefits of micro-switches, improvements must be made to address performance and reliability shortfalls which have long been an issue with this application. To improve the performance of these devices, the micro-contacts used in this technology must be understood to allow for design improvements, and offer a means for testing to validate this technology and determine when such improvements are ready for operational environments. To build devices which are more robust and capable of continued operation after billions of cycles requires that …

Improving The Speech Intelligibility By Cochlear Implant Users, Behnam Azimi

Theses and Dissertations

In this thesis, we focus on improving the intelligibility of speech for cochlear implants (CI) users. As an auditory prosthetic device, CI can restore hearing sensations for most patients with profound hearing loss in both ears in a quiet background. However, CI users still have serious problems in understanding speech in noisy and reverberant environments. Also, bandwidth limitation, missing temporal fine structures, and reduced spectral resolution due to a limited number of electrodes are other factors that raise the difficulty of hearing in noisy conditions for CI users, regardless of the type of noise. To mitigate these difficulties for CI …

Study Of Computational Image Matching Techniques: Improving Our View Of Biomedical Image Data, Ahmadreza Baghaie

Theses and Dissertations

Image matching techniques are proven to be necessary in various fields of science and engineering, with many new methods and applications introduced over the years. In this PhD thesis, several computational image matching methods are introduced and investigated for improving the analysis of various biomedical image data. These improvements include the use of matching techniques for enhancing visualization of cross-sectional imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI), denoising of retinal Optical Coherence Tomography (OCT), and high quality 3D reconstruction of surfaces from Scanning Electron Microscope (SEM) images. This work greatly improves the process of data …

Solid State Protective Device Topological Trade-Offs For Mvdc Systems, Vikas Singh

Theses and Dissertations

Presently accepted approaches to protection are “Unit-Based” which means the power converter(s) feeding the bus coordinate with no-load electromechanical switches to isolate faulted portions of the bus. However, “Breaker-Based” approaches, which rely upon solid state circuit breakers for fault mitigation can result in higher reliability of power and potentially higher survivability. The inherent speed of operation of solid state protective devices will also play a role in fault isolation, hence reducing stress level on all system components. A comparison study is performed of protective device topologies that are suitable for shipboard distribution systems rated between 4kVdc and 20kVdc from the …

A Secure, Reliable And Performance-Enhancing Storage Architecture Integrating Local And Cloud-Based Storage, Christopher Glenn Hansen

Theses and Dissertations

The constant evolution of new varieties of computing systems - cloud computing, mobile devices, and Internet of Things, to name a few - have necessitated a growing need for highly reliable, available, secure, and high-performing storage systems. While CPU performance has typically scaled with Moore's Law, data storage is much less consistent in how quickly performance increases over time. One method of improving storage performance is through the use of special storage architectures. Such architectures often include redundant arrays of independent disks (RAID). RAID provides a meaningful way to increase storage performance on a variety of levels, some higher-performing than …

An Ion Detection Scheme Employing Solid State Devices For Use In Portable Mass Spectrometers, Sanjiv Nath Pant

Theses and Dissertations

This thesis presents a solid state approach to the ion detection system used in the back-end of modern mass spectrometers. Although various techniques already exist to detect ions – even with the sensitivity of a single particle, the existing techniques require high voltage or lower operation temperature to counteract the noise inherent in the system. The suggested design presents an alternative to the more popular detection system whereby the requirement of high operation voltage or low operation temperature can be precluded. This is made possible through the gate capacitance of a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). This thesis …

Voltage Measurement Using Slab-Coupled Optical Sensors With Polarization-Maintaining And Absorption-Reduction Fiber, Rex Lavell King

Theses and Dissertations

This research presents the first use of side-polished Panda fiber in the fabrication of slab-coupled optical sensors (SCOS). It is determined that the Panda SCOS provides a sensor that is comparable to the D-fiber SCOS in cases of electric field sensing. It exhibits greater power transfer and higher bandwidth than a typical D-SCOS. The Panda SCOS is also less costly and easier to splice than the D-fiber alternative. This comes at a cost of slightly decreased sensitivity and a more fragile fabrication process. This research also demonstrates the use of the Panda-SCOS as means of voltage characterization across both the …

Router Security Effect On Performance Of A Network, David L. Leal

Theses and Dissertations

Recently many of the devices that create a computer network offer security to help protect networks from hackers, such as computers, servers, firewalls and even routers. In most cases when protecting a network from hackers having more security is not always the best, because the more resources of the device is used by the security in inspecting connections, and it can compromise performance of the network.

This thesis investigates performance benefit of having security on a router and its impact on the connection rate of the network when it is under security attacks. In this thesis, different security features and …

Low Temperature Flexible Perovskite Solar Cell With Mesoporous Tio2 Electron Transport Layer In High Humidity Environment, Felipe De La Torre

Theses and Dissertations

Perovskite solar cells are the fastest advancing solar technology to date with efficiencies increasing from 3.9% to more than 21% within a few years. They have emerged as a possible alternative to silicon photovoltaics due to their exceptional photovoltaic performance, light absorbing properties, and low-cost fabrication with methylammonium lead iodide (CH3NH 3PbI3) getting considerable interest in research and development. However, there are still many challenges that must be addressed for perovskite solar cells to replace contemporary solar cells, such as improving their stability, making them nonhazardous, further increasing their efficiency, and developing better techniques for large scale fabrication. In this …

Specialized Distributed Hardware Design For Real-Time Atmospheric Turbulence Mitigation Error Correction Calculation, Subhadra Subramanian

Theses and Dissertations

This thesis demonstrates an approach to solve execution challenges of Image processing of an Atmospheric turbulence mitigation technique in real-time. An atmospheric turbulence mitigation technique is used to eliminate the aberrations caused by turbulence in the images. The error calculation is a mathematically intensive process, that includes Fast Fourier Transform (FFT) to convert the image from the spatial domain to the spatial frequency domain. The FPGA based hardware accelerator design and architectures are investigated in this work to perform Fast Fourier Transform and error calculations in real-time, defined as 30Hz. A scalable and parallel platform is designed to execute the …

Analysis Of The Fm Radio Spectrum For Secondary Licensing Of Low-Power Short-Range Cognitive Internet-Of-Things Devices Via Cognitive Radio, Derek Thomas Otermat

Theses and Dissertations

The number of Internet of Things (IoT) devices is predicated to reach 200 billion by the year 2020. This rapid growth is introducing a new class of low-power short-range wireless devices that require the use of radio spectrum for the exchange of information. To offset this extraneous demand for radio spectrum, the low-power short-range IoT devices need to utilize vacant spectrum through the use of Cognitive Radio (CR). The analysis presented in this dissertation indicates that the FM radio spectrum is underutilized in areas of the continental United States that have a population of 100,000 or less. These locations have …

A Robust Speaker Identification Algorithm Based On Atomic Decomposition And Sparse Redundant Dictionary Learning, Thomas James Bryan Jr.

Theses and Dissertations

Speaker identification is performed in high additive white Gaussian noise environments by processing sounds as images in the time-frequency plane. The technique creates audio streams that remove background noise from speech while preserving speech quality. Atomic decomposition is implemented by the matching pursuit algorithm using Gabor or gammatone atomic dictionaries. Gabor atoms were originally proposed as fundamental building blocks of speech; whereas, gammatone atoms closely resemble the human cochlear impulse response. Atomic decomposition creates a sparsely populated time-frequency vector referred to as weight space. The populated positions in weight space have amplitude weights that are proportional to localized energy in …

Angle Of Attack Visualization: A Proposal For A Tangible Interactive In-Flight Loss Of Control Recovery System, Nicholas Kasdaglis

Theses and Dissertations

The Trajectory Recovery System (TRS) is a proposed system that will help a pilot quickly restore the aircraft to controlled flight. In-flight Loss of Control (I-LOC) is the leading cause of aviation fatalities. While attempts to address this threat have mainly focused upon prevention and avoidance, there has been little offered for recovery from an I-LOC event. The work presented herein addresses this gap. Offered here will be a Human- Centered Design (HCD) solution to the problem of I-LOC. The TRS is a real-world application arising from robust multi-agent models of human-automation teaming. The use of such models transforms cognitive …

Absolute Positioning Using The Earth's Magnetic Anomaly Field, Aaron J. Canciani

Theses and Dissertations

Achieving worldwide alternatives to GPS is a challenging engineering problem. Current GPS alternatives often suffer from limitations such as where and when the systems can operate. Navigation using the Earth's magnetic anomaly field, which is globally available at all times, shows promise to overcome many of these limitations. We present a navigation filter which uses the Earth's magnetic anomaly field as a navigation signal to aid an inertial navigation system (INS) in an aircraft. The filter utilizes highly-accurate optically pumped cesium (OPC) magnetometers to make scalar measurements of the Earth's magnetic field and compare them to a map using a …

Physical Layer Defenses Against Primary User Emulation Attacks, Joan A. Betances

Theses and Dissertations

Cognitive Radio (CR) is a promising technology that works by detecting unused parts of the spectrum and automatically reconfiguring the communication system's parameters in order to operate in the available communication channels while minimizing interference. CR enables efficient use of the Radio Frequency (RF) spectrum by generating waveforms that can coexist with existing users in licensed spectrum bands. Spectrum sensing is one of the most important components of CR systems because it provides awareness of its operating environment, as well as detecting the presence of primary (licensed) users of the spectrum.

Rapidscat Slice Spatial Response Function Contour Parameterization, John Clyde Niedfeldt

Theses and Dissertations

The spatial response function (SRF) of the backscatter measurements for a radar scatterometer is often used in reconstruction. It has been found that in many cases the SRF can be approximated as a binary function that is 1 inside the - 6 dB contour of the SRF and 0 outside. This improves the computation speed of reconstruction. Computing the SRF contour can still be a lengthy computation, which can be simplified by precomputing and tabulating key SRF contours. The tabular parameterization for many spinning scatterometers, i.e., QuikSCAT, is straight-forward. For RapidSCAT, this estimation is more involved than other radars due …

An Exploration In Fiber Optic Sensors, Frederick Alexander Seng

Theses and Dissertations

With the rise of modern infrastructure and systems, testing and evaluation of specific components such as structural health monitoring is becoming increasingly important. Fiber optic sensors are ideal for testing and evaluating these systems due many advantages such as their lightweight, compact, and dielectric nature. This thesis presents a novel method for detecting electric fields in harsh environments with slab coupled optical sensors (SCOS) as well as a novel method for detecting strain gradients on a Hopkinson bar specimen using fiber Bragg gratings (FBG). Fiber optic electric field sensors are ideal for characterizing the electric field in many different systems. …

Robust Speaker Recognition In The Presence Of Speech Coding Distortion, Robert Walter Mudrosky

Theses and Dissertations

For wireless remote access security, forensics, border control and surveillance applications, there is an emerging need for biometric speaker recognition systems to be robust to speech coding distortion. This thesis examines the robustness issue for three coders, namely, the ITU-T 6.3 kilobits per second (kbps) G.723.1, the ITU-T 8 kbps G.729 and the 12.2 kbps 3GPP GSM-AMR coder. Both speaker identification (SI) and speaker verification (SV) systems are considered and use a Gaussian mixture model (GMM) classifier. The systems are trained on clean speech and tested on the decoded speech. To mitigate the performance loss due to mismatched training and …

Wireless Power Transfer Using Class-De Converter Via Strongly Coupled Two Planar Coils, Ayetullah Bahadir Biten

Theses and Dissertations

WIRELESS POWER TRANSFER USING CLASS-DE CONVERTER

VIA

STRONGLY COUPLED TWO PLANAR COILS

by

Ayetullah Bahadir Biten

The University of Wisconsin – Milwaukee, August 2016

Under the supervision of Professor Adel Nasiri

Wireless power systems are getting popular with the improvement in the technology not just because it is a fancy and cool conception but also because it is more convenient and safer in some applications. For example, this project aims to help high power data center design to be changed to wirelessly powered center to provide a safe and hands-on work environment even under different load conditions. Thinking of the …

The Study Of Locating Ground Faults In Dc Microgrid Using Wavelet Transform, Ruijing Yang

Theses and Dissertations

As the proliferations of distributed generation and power electronic equipment in power systems, direct current (DC) microgrid emerged and attracted more and more researchers’ attentions. Protection of DC microgrid is a big challenge and to build a well-function protection system, locating the faults accurately is a critical issue. It is easy to find the location of short circuit faults in DC microgrid. However, it is difficult to locate ground faults in DC microgrid because of the spray capacitors and the large amount of distributed resources.

In this thesis, Wavelet Transform is applied to decompose the common mode currents that is …

A Visual Return-To-Home System For Gps-Denied Flight, Benjamin Paul Lewis

Theses and Dissertations

Unmanned aerial vehicle technology is rapidly maturing. In recent years, the sight of hobbyist aircraft has become more common. Corporations and governments are also interested in using drone aircraft for applications such as package delivery, surveillance and communications. These autonomous UAV technologies demand robust systems that perform under any circumstances. Many UAV applications rely on GPS to obtain information about their location and velocity. However, the GPS system has known vulnerabilities, including environmental signal degradation, terrestrial or solar weather, or malicious attacks such as GPS spoofing. These conditions occur with enough frequency to cause concern. Without a GPS signal, the …

An Energy Efficient, Load Balancing, And Reliable Routing Protocol For Wireless Sensor Networks, Kamil Samara

Theses and Dissertations

AN ENERGY EFFICIENT, LOAD BALANCING, AND RELIABLE ROUTING PROTOCOL FOR WIRELESS SENSOR NETWORKS

by

Kamil Samara

The University of Wisconsin-Milwaukee, 2016

Under the Supervision of Professor Hossein Hosseini

The Internet of Things (IoT) is shaping the future of Computer Networks and Computing in general, and it is gaining ground very rapidly. The whole idea has originated from the pervasive presence of a variety of things or objects equipped with the internet connectivity. These devices are becoming cheap and ubiquitous, at the same time more powerful and smaller with a variety of onboard sensors. All these factors with the availability of …

Transient Control Of Synchronous Machine Active And Reactive Power In Micro-Grid Power Systems, Luke Gerard Weber

Theses and Dissertations

There are two main topics associated with this dissertation. The first is to investigate

phase–to–neutral fault current magnitude occurring in generators with multiple zero–sequence

current sources. The second is to design, model, and tune a linear control system for oper-

ating a micro–grid in the event of a separation from the electric power system.

In the former case, detailed generator, AC8B excitation system, and four–wire electric

power system models are constructed. Where available, manufacturers data is used to

validate the generator and exciter models. A gain–delay with frequency droop control

is used to model an internal combustion engine and governor. …

Probabilistic Reliability Analysis Of Electric Power Systems With Smart Grid Technologies And Water Distribution Networks: Modeling, Assessment, And Comparison, Ruosong Xiao

Theses and Dissertations

With the rapid growth of population, the modern human society is becoming more and more dependent on the proper operation of critical infrastructures - the interconnected electrical power system, the drinking water distribution and supply system, the natural gas transmission and distribution system, and so forth. It has become an important issue to maintain reliable functions of these critical systems. As a result, comprehensive reliability evaluation is highly needed to quantify their reliability in an objective manner. Conventionally, deterministic criteria were used in reliability evaluations. However, it lacked the ability to model and quantify the stochastic nature of system behaviors …

Deep Tissue Light Delivery And Fluorescence Tomography With Applications In Optogenetic Neurostimulation, Mehdi Azimipour

Theses and Dissertations

Study of the brain microcircuits using optogenetics is an active area of research. This method has a few advantages over the conventional electrical stimulation including the bi-directional control of neural activity, and more importantly, specificity in neuromodulation. The first step in all optogenetic experiments is to express certain light sensitive ion channels/pumps in the target cell population and then confirm the proper expression of these proteins before running any experiment. Fluorescent bio-markers, such as green fluorescent protein (GFP), have been used for this purpose and co-expressed in the same cell population. The fluorescent signal from such proteins provides a monitory …

Repair Severed Nerve Connections Through A Multi-Branch Microchannel Scaffold To Control The Direction Of The Regenerated Nerve, Luis Enrique Castanuela Ramon

Theses and Dissertations

Damage to the peripheral nervous system may result in functional abnormalities due to disrupted nerve connections. Existing methods of repairing severed nerve connections in the peripheral nervous system have limitations and disadvantages such as a limited availability of donor nerves and a lack of control of the direction of nerve regeneration within nerve conduits. A handcrafted multi-branch microchannel scaffold improves upon the current methods of nerve repair by incorporating microchannels, which guide and accommodate the nerve regeneration to distal ends, allowing for the treatment of nerve injuries involving multiple branches with fewer surgeries. This scaffold is also made more accessible …

Biocompatible Microchannel Scaffold With Microwires For Recording Regenerative Peripheral Nerve Neural Spikes, Manisankar Chennamsetti

Theses and Dissertations

A new process for the fabrication of a microchannel scaffold with microwires for peripheral nerve applications is presented. This microchannel scaffold implemented between the ends of nerves, the axons of which regenerate through microchannel in scaffold and fixed microelectrodes. This device is entirely handcrafted using commercially available materials such as microwires, PDMS film, liquid PDMS, dental cement, and epoxy glue. This device was implemented in the a Lewis rat sciatic nerve to better analyze the electrical signals of regenerated axons. 64-electrode microchannel scaffolds were developed for both peripheral nerve interfacing and peripheral nerve regeneration. The microwires were used for recording …

The Effects Of Antenna Coupling In A Mimo Radar System, Benjamin T. Arnold

Theses and Dissertations

A mathematical model for a multiple-input multiple-output radar system is presented. The model is used to track signals through the system in order to identify the impact of antenna array mutual coupling on radar system performance. Simulations using the model provide quantitative assessment of the performance degradation as a function of antenna coupling strength. Specifically, the results show that coupling can cause a target to appear at an angle notably different than its actual angle and can cause an increase in the side lobe level. A compensation technique is presented that completely removes these effects for practical levels of coupling. …

An Improved Ship Design Tool For Comparing Performance Of Multiple Ship Designs Across User-Defined Missions, Helder Jose De Almeida Pais

Theses and Dissertations

In the early stages of ship design, engineers from many different disciplines need to have confidence that a design being produced converges across the electrical, mechanical, and thermal domains, and that the design meets the needs of the stakeholders, and, that a particular design performs better or more optimally than other designs produced to accomplish a mission. The tools currently available do not permit the engineering teams to gain this insight in a reasonable amount of time. In this thesis, we discuss the improvements that we have made to our existing ship design tools in the S3D environment, allowing for …