Engineering Commons^™

Implementing A Wireless Monitoring Solution For A Biomechanical Telemetry System, Hyung Suk Kim

Open Access Theses

Sport-related Traumatic Brain Injury (TBI) is one of the major concerns for collision based sports athletes and their families. The ability to measure impacts on the head is imperative to monitor brain injury and prevent serious TBI. Recent research by the Purdue Neurotrauma Group (PNG) indicates that accumulation of subconcussive impacts may cause permanent neurological damage. Currently available commercial impact monitoring systems are designed as an event-based models which collect impact data above pre-determined acceleration thresholds. To track long-term effects of sub-concussive impacts, event-based modeling is inadequate. The PNG developed a biomechanical sports telemetry system that is capable of storing …

Improvement Of A Biomechanical Telemetry System Hardware Platform, Soon Ho Kwon

Open Access Theses

Traumatic brain injuries (TBI) while playing sports are a major concern for the general public today. Recently, studies have shown that repetitive subconcussive hits can lead to neurological disorders. In order to prevent the athletes from suffering traumatic brain injuries, many organizations related to contact based sports and the military employ commercialized head impact telemetry systems. However, a majority of the commercialized systems is event based which only collects the linear acceleration that exceeds a certain threshold. To accurately record and utilize the data from the impact telemetry system, it is necessary to record all the linear and angular acceleration …

A High-Performance Communication Topology For Decentralized Protocols, Raza A. Khan

Open Access Theses

Preserving transaction atomicity and ensuring its commitment is key to the maintenance of data integrity in a distributed database. The distributed consensus protocol is a prominent example of a mechanism used to accomplish safe commitment of a distributed transaction. These protocols are based primarily on repeated message exchange among all sites/nodes and their performance is characterized not only by the number of these messages but also by the underlying communication topology. This thesis proposes a measure of performance known as average message complexity and proposes a communication structure based on folded even graphs called the Folded Even Network (FEN). Performance …

Efficient Inelastic Scattering In Atomistic Tight Binding, James A. Charles

Open Access Theses

In this thesis, the coherent and incoherent transport simulation capabilities of the multipurpose nanodevice simulation tool NEMO5 are presented and applied on transport in tunneling field-effect transistors (TFET). A gentle introduction is given to the non-equilibrium Green's function theory. The comparison with experimental resistivity data confirms the validity of the electron-phonon scattering models. Common pitfalls of numerical implementations such as current conservation, energy mesh resolution, and recursive Green's function stability and the applicability of common approximations of scattering self-energies are discussed. The impact of phonon-assisted tunneling on the performance of TFETs is exemplified with a concrete Si nanowire device. The …

An Led-Based Image Sensor With Energy Harvesting And Projection Capabilities College Of Technology, Xiaozhe Fan

Open Access Theses

The light emitting diode (LED) technology has experienced great improvements in efficiency and cost reduction since the first visible light LED was invented in 1962. At the same time, because LEDs exhibit excellent photovoltaic performance, their capabilities of sensing light and harvesting energy have also been explored and studied for many years. By triple functionality of LEDs, they are widely used in a variety of research areas including visible light communication, robotics, structured light application and so on. Meanwhile, this triple functionality of LEDs also inspired researchers to combine and implement different functions in one system.

In this thesis, An …

Image Quality Estimation: Soft-Ware For Objective Evaluation, He Liu

Open Access Theses

Digital images are widely used in our daily lives and the quality of images is important to the viewing experience. Low quality images may be blurry or contain noise or compression artifacts. Humans can easily estimate image quality, but it is not practical to use human subjects to measure image quality in real applications. Image Quality Estimators (QE) are algorithms that evaluate image qualities automatically. These QEs compute scores of any input images to represent their qualities. This thesis mainly focuses on evaluating the performance of QEs. Two approaches used in this work are objective software analysis and the subjective …

Analysis Of Structural And Functional Brain Networks, Jun Young Jeong

Open Access Theses

The brain is a representative example of a network. It consists of numerous spatially distributed regions that continuously exchange information through structural connections. In the past decade, an increasing number of studies have explored the brain network in both structural and functional aspects; they have begun to decipher complex brain wirings, as well as elucidate how the rich functionality emerges from this architecture. Based upon previous studies, this thesis addresses three critical gaps in the field. (I) Although it is known that the community structures of brain network are spatially overlapping, conventional studies have focused on grouping brain regions into …

Exploratory Study Of Students' Representational Fluency And Competence Of Electric Circuits, William Fernando Sandchez Cossio

Open Access Theses

Electric circuits are extensively used in today’s devices as computers, phones, cameras and others. This makes them a crucial topic in engineering because almost every engineering branch could be related of used them at different levels. Even though their importance, students often struggle during the learning process of circuit analysis topics. Additionally, other very important abilities for engineering students are the capacities to create, use, express and think about models and representations of technical concepts; and the capacities to translate and map from one representation to another. These abilities are known as representational competence and representational fluency respectively.

The purpose …

Novel Gain Enhancement Technique For Microstrip Patch Antennas Based On Multi-Pronged Feed Network Synthesis, Brian J. Vaughn

Open Access Theses

Developing antennas with enhanced gain has always been an important pursuit within the antenna community, as a higher gain leads to an increase in the received power for any given wireless link. In general, when a higher gain is needed for an application, only certain types of antennas can be used. The goal of this thesis project was to develop a method for increasing the gain of antennas that already exist by applying modifications to them, expanding the design flexibility for wireless applications. In this thesis, a novel method for increasing the gain of microstrip patch antennas by synthesizing specialized …

Fast Voxel Line Update For Time-Space Image Reconstruction, Xiao Wang

Open Access Theses

Recent applications of model-based iterative reconstruction(MBIR) algorithm to time-space Computed Tomography (CT) have shown that MBIR can greatly improve image quality by increasing resolution as well as reducing noise and some artifacts. Among the various iterative methods that have been studied for MBIR, iterative coordinate descent(ICD) has been found to have relatively low overall computational requirements due to its fast convergence. However, high computational cost and long reconstruction times remain as a barrier to the use of MBIR in practical applications. This disadvantage is especially prominent in time-space reconstruction because of the large volume of data. This thesis presents a …

Magnetic Equivalent Circuit Based Permanent Magnet Characterization, Vinicius Cabral Do Nascimento

Open Access Theses

This thesis sets forth a permanent magnet characterization fixture and procedure. The work begins with a review of the state of the art in permanent magnet characterization. It then sets forth a new characterization fixture. The proposed system relies on the use of low cost sensors to perform the necessary measurements, which consists of search coils, hall sensors, and current probes. A magnetic equivalent circuit is set forth to analyze the fixture and for use in identification of permanent magnet parameters. The characterization procedure is based on an experimentally defined magnetic equivalent circuit. An experimental approach to model the tester …

Ibeacon Based Proximity And Indoor Localization System, Faheem Faheem

Open Access Theses

User location can be leveraged to provide a wide range of services in a variety of indoor locations including retails stores, hospitals, airports, museums and libraries etc. The widescale proliferation of user devices such as smart phones and the interconnectivity among different entities, powered by Internet of Things (IoT), makes user device-based localization a viable approach to provide Location Based Services (LBS). Location based services can be broadly classified into 1) Proximity based services that provides services based on a rough estimate of users distance to any entity, and 2) Indoor localization that locates a user's exact location in the …

Mixed Mesh/Nodal Magnetic Equivalent Circuit Modeling Of A Six-Phase Claw-Pole Automotive Alternator, Daniel C. Horvath

Open Access Theses

Magnetic equivalent circuits (MECs) have been employed by many researchers to model the relationship between magnetic flux and current in electromagnetic systems such as electric machines, transformers and inductors [1] ,[2]. Magnetic circuits are analogous to electric circuits where voltage, current, resistance and conductance are the respective counterparts of magneto-motive force (MMF), magnetic flux, reluctance and permeance. The solution of MECs can be accomplished with the plethora of techniques developed for electrical circuit analysis. Specifically, mesh analysis, based on Kirchoff’s Voltage Law (KVL), and nodal analysis, based on Kirchoffs Current Law (KCL), are two very common solution techniques. Once an …

Design Of An Asymmetric Reluctance Machine For A Generator Application, Bryan David Marquet

Open Access Theses

This work compares an Asymmetric Reluctance Machine (ARM) to a Uniform air Gap Reluctance Machine (UGRM) for a generator application. The ARM employs an asymmetric rotor pole to increase machine performance, specifically increasing torque density. A multi-objective optimization is employed to minimize mass and loss subject to design constraints. Two machines are compared in terms of their Pareto-optimal fronts.

Capacity Optimization Of Battery-Generator Hybrid Power System: Toward Minimizing Maintenance Cost In Expeditionary Basecamp/Operational Energy Applications, Jude C. Onwuanumkpe

Open Access Theses

Low and transient load condition are known to have deleterious impact on the efficiency and health of diesel generators (DGs). Extensive operation under such loads reduces fuel consumption and energy conversion efficiency, and contribute to diesel engine degradation, damage, or catastrophic failure. Non-ideal loads are prevalent in expeditionary base camps that support contingency operations in austere environments or remote locations where grid electricity is either non-existent or inaccessible. The impact of such loads on DGs exacerbates already overburdened basecamp energy logistics requirements. There is a need, therefore, to eliminate or prevent the occurrence of non-ideal loads. Although advances in diesel …

A Methodology For Cooperation Between Electric Utilities And Consumers For Microgrid Utilization Based On A Systems Engineering Approach, Franklin E. Pacheco Chiguano

Open Access Theses

In recent years, the energy market has experienced important challenges in its structure and requirements of its actors, such as the necessity for more reliable electric service, energy efficiency, environmental care practices, and the incorporation of decentralized power generation based on distributed energy resources (DER). Given this context, microgrids offer several advantages to the grid and its actors. However, few microgrid projects have been implemented, and the participation of electric utilities is lower than the expected. Hence, this research explores how electric utility - customer interactions can accommodate mutual benefits for both parties through the proposal of a Microgrid Reference …

Optimization Of Wireless Power Networks For Biomedical Applications, Kyle A. Thackston

Open Access Theses

Successful physiological integration of electronics will open the doors to new methods of treatment and diagnoses. One of the key challenges of this integration is designing devices as small as possible while still maintaining high functionality, such as bio-signal recording, processing, telemetry, and stimulation. Wireless power transfer (WPT) can help shrink a device’s footprint by removing the need for bulky batteries. While many modalities of WPT exist for biomedical applications, the optimal power transfer efficiency (PTE) is seldom achieved due to improper impedance matching. Existing methods for determining the optimal impedance matching conditions tend to be application specific and make …