Engineering Commons^™

Implementation Of Analytical Fatigue Models Into Opensim To Predict The Effects Of Fatigue On Anterior Cruciate Ligament Loading, Michael A. Samann

Mechanical & Aerospace Engineering Theses & Dissertations

The anterior cruciate ligament (ACL) provides stability to the knee joint while performing activities such as a side step cut. Neuromuscular fatigue, a reduction in muscle force producing capabilities, alters lower extremity mechanics while performing a side step cut and may increase the risk of ACL injury, particularly in females. Musculoskeletal modeling allows for the measurement of muscle forces, which are difficult to measure in-vivo. Therefore, musculoskeletal modeling, may improve our understanding of the effects of neuromuscular fatigue on muscle force production and loading of the ACL. Therefore, the purpose of this study was to develop a musculoskeletal model which …

Empirical Modeling Of Asynchronous Scalp Recorded And Intracranial Eeg Potentials, Komalpreet Kaur

Electrical & Computer Engineering Theses & Dissertations

A Brain-Computer Interface (BCI) is a system that allows people with severe neuromuscular disorders to communicate and control devices using their brain signals. BCIs based on scalp-recorded electroencephalography (s-EEG) have recently been demonstrated to provide a practical, long-term communication channel to severely disabled users. These BCIs use time-domain s-EEG features based on the P300 event-related potential to convey the user's intent. The performance of s-EEG-based BCIs has generally stagnated in recent years, and high day-to-day performance variability exists for some disabled users. Recently intracranial EEG (i-EEG), which is recorded from the cortical surface or the hippocampus, has been successfully used …

A Framework For Web Object Self-Preservation, Charles L. Cartledge

Computer Science Theses & Dissertations

We propose and develop a framework based on emergent behavior principles for the long-term preservation of digital data using the web infrastructure. We present the development of the framework called unsupervised small-world (USW) which is at the nexus of emergent behavior, graph theory, and digital preservation. The USW algorithm creates graph based structures on the Web used for preservation of web objects (WOs). Emergent behavior activities, based on Craig Reynolds’ “boids” concept, are used to preserve WOs without the need for a central archiving authority. Graph theory is extended by developing an algorithm that incrementally creates small-world graphs. Graph theory …

Idpal – A Partially-Adiabatic Energy-Efficient Logic Family: Theory And Applications To Secure Computing, Mihail T. Cutitaru

Electrical & Computer Engineering Theses & Dissertations

Low-power circuits and issues associated with them have gained a significant amount of attention in recent years due to the boom in portable electronic devices. Historically, low-power operation relied heavily on technology scaling and reduced operating voltage, however this trend has been slowing down recently due to the increased power density on chips. This dissertation introduces a new very-low power partially-adiabatic logic family called Input-Decoupled Partially-Adiabatic Logic (IDPAL) with applications in low-power circuits. Experimental results show that IDPAL reduces energy usage by 79% compared to equivalent CMOS implementations and by 25% when compared to the best adiabatic implementation. Experiments ranging …

Evaluation Of Degradation In Gan High Electron Mobility Transistors Due To The Inverse Piezoelectric Effect, Deepthi Nagulapally

Electrical & Computer Engineering Theses & Dissertations

It has recently been postulated that high voltage stress can result in the degradation of nanoscale structures that are made up of piezoelectric materials. The inverse piezoelectric effect (IPE) is believed to be the likely reason for this degradation mechanism. Basically, the IPE leads to the creation of high internal stresses driven by the presence of an electric field. Consequently, devices based on piezoelectric materials are postulated to undergo defect formation induced by the large mechanical stress arising from the inverse piezoelectric effect in the presence of an applied bias. GaN based devices are mostly observed to show this degradation …

High Dimensional Data Set Analysis Using A Large-Scale Manifold Learning Approach, Loc Tran

Electrical & Computer Engineering Theses & Dissertations

Because of technological advances, a trend occurs for data sets increasing in size and dimensionality. Processing these large scale data sets is challenging for conventional computers due to computational limitations. A framework for nonlinear dimensionality reduction on large databases is presented that alleviates the issue of large data sets through sampling, graph construction, manifold learning, and embedding. Neighborhood selection is a key step in this framework and a potential area of improvement. The standard approach to neighborhood selection is setting a fixed neighborhood. This could be a fixed number of neighbors or a fixed neighborhood size. Each of these has …

Feasibility Of Mainstream Nitrite Oxidizing Bacteria Out-Selection And Anammox Polishing For Enhanced Nitrogen Removal, Pusker Raj Regmi

Civil & Environmental Engineering Theses & Dissertations

Short-cut nitrogen removal avoids nitrite oxidation to nitrate by nitrite oxidizing bacteria (NOB) and allows a) reduction of formed nitrite to nitrogen gas via heterotrophic denitrification and/or b) oxidation of remaining ammonia with formed nitrite to nitrogen gas via anaerobic ammonia oxidation (anammox). The precondition for achieving shortcut nitrogen removal is suppression of NOB, which is favored by warm and high ammonia strength conditions found in internally generated ammonia-rich waste streams through anaerobic digestion of waste solids referred to as sidestreams or reject water. The discovery of anammox bacteria in the mid-1990s, which are capable of transforming NH₄+ …

Graphical Display Of The Effect Of Three Cash Flow Elements For Sensitivity Analysis, Kawintorn Pothanun

Engineering Management & Systems Engineering Theses & Dissertations

Sensitivity analysis is one of the most important analysis techniques in a decision making process. The analytic intent behind sensitivity analysis is the variation of parameters in data models, and the examination of the effect of these variations on the outcome of the models. There are four primary benefits from conducting a sensitivity analysis: (a) sensitivity analysis facilitates the decision makers' development of recommendations, (b) sensitivity analysis serves as a tool for communication among stakeholders or decision makers in a project or an organization, (c) sensitivity analysis increases overall understanding of the decision models, and (d) sensitivity analysis serves as …

Proceedings, Msvscc 2014, Old Dominion University, Department Of Modeling, Simulation & Visualization Engineering, Old Dominion University, Virginia Modeling, Analysis & Simulation Center

Modeling, Simulation and Visualization Student Capstone Conference

Proceedings of the 8th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 17, 2014 at VMASC in Suffolk, Virginia.

Section Abstracts: Astronomy, Mathematics, And Physics With Materials Science

Virginia Journal of Science

Abstracts of the Astronomy, Mathematics, and Physics with Materials Science Section for the 92nd Annual Meeting of the Virginia Academy of Science, May 13-15, 2014, Virginia Commonwealth University, Richmond, Virginia

Section Abstracts: Biomedical And General Engineering

Virginia Journal of Science

Abstracts of the Biomedical and General Engineering Section for the 92nd Annual Meeting of the Virginia Academy of Science, May 13-15, 2014, Virginia Commonwealth University, Richmond, Virginia

Stormwater Infrastructure Optimization On Conjunctive Improvements, Mohammad Hussin Shar

Civil & Environmental Engineering Theses & Dissertations

The studied drainage system is located in the downtown of the City of Newport News, in a basin known as Anderson Park. The drainage system collects and conveys rainfall runoffs to the system outfall located at the shoreline of the Hampton Roads body of water, which is located south of the study area. The aim of this study is to analyze the area's drainage system, determine maximum capacities, identify system deficiencies and generate the most possible, practical and economical solution for fixing the system deficiencies.

After collecting all of required data, the drainage system was modeled and calibrated using the …

An Investigation Of Business Transformation Disruptors At The Military Strategic Command Level, Thomas Bock

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation contributes an empirical research on business transformation disruption in the military. Specifically, this exploratory research seeks a better understanding of disruption of business transformation and some of the factors that are likely to impact the transformation process at the military strategic command level. A lack of empirical studies existing in the literature, coupled with the continuous transformation challenges faced by military organizations, make it necessary to conduct this empirical study of business transformation disruption in the military.

This research was carried out utilizing a two-phase mixed-methods approach. The first phase included qualitative data gathering through a series of …

A Systems-Based Framework For The Assessment Of Performance Measurement System Implementations In R&D Organizations, Kenneth S. Baggett Jr.

Engineering Management & Systems Engineering Theses & Dissertations

Performance measurement is utilized by organizations in all industries, including research and development (R&D). Measures are developed, data are collected, and the measurement results are used to drive the organization. The implicit hope is, of course, that the measures drive the organization to improve. However, literature identifies high failure rates directly related to performance measurement system (PMS) implementations. Establishing the fundamental operational characteristics associated with successful PMSs would provide a significant contribution towards the establishment of PMS assessment criteria. This research addresses this gap through the use of a grounded theory method employed to identify these operational characteristics, assesses the …

The Relationship Among Hfacs Levels And Analysis Of Human Factors In Unmanned And Manned Air Vehicles, Veysel Yesilbas

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation analyzes the structural relationships among the Human Factors Accident Classification System levels for unmanned air vehicle and manned air vehicle accidents and the common relationships between unmanned air vehicle and manned air vehicle accident causes. The study acquired DOD HFACS accident classification data from 347 United States Air Force Class A accident reports for the years between 2000 and 2013.

The dissertation utilized a set of analysis that is considered to contribute substantially to the respective domain of the study. The correlations found among categorical levels were applied to HFACS taxonomy based on the Reason Model via path …

Transparent Spectrum Co-Access In Cognitive Radio Networks, Jonathan Daniel Backens

Electrical & Computer Engineering Theses & Dissertations

The licensed wireless spectrum is currently under-utilized by as much as 85%. Cognitive radio networks have been proposed to employ dynamic spectrum access to share this under-utilized spectrum between licensed primary user transmissions and unlicensed secondary user transmissions. Current secondary user opportunistic spectrum access methods, however, remain limited in their ability to provide enough incentive to convince primary users to share the licensed spectrum, and they rely on primary user absence to guarantee secondary user performance. These challenges are addressed by developing a Dynamic Spectrum Co-Access Architecture (DSCA) that allows secondary user transmissions to co-access transparently and concurrently with primary …

Generation Of Bipolar Nanosecond Pulses, Sambasiva Rao Rajulapati

Electrical & Computer Engineering Theses & Dissertations

Bipolar pulse generation has been studied using transmission line technology, which was mainly used for monopolar pulse generation. In this thesis, low impedance, high current, nanosecond pulse generators were designed, constructed and tested. Five transmission lines were connected in parallel, so the impedance was 10 n. The transmission lines were switched by a spark gap switch operated in air. The closing of the switch creates a matched condition on one side of the transmission lines and a short circuit on the other side of the transmission lines. When the transmission lines are precharged, one of the two waves in opposite …

Synthesis Of Nanolaminate Structures Of Alternating Layers Of Lead Telluride And Lead Selenide By Atomic Layer Deposition For Thermoelectric Applications, Arun Deepak Ramalingom Pillai

Electrical & Computer Engineering Theses & Dissertations

Alloys composed of lead, telluride and selenide compounds exhibit very high figure of merit ZT values at intermediate temperatures, making them exceptional thermoelectric materials in a particular temperature range. Advancement in thermoelectric devices and applications hinges on increasing ZT, which is a ratio of the thermoelectric power factor to the thermal conductivity. One of the proposed avenues to achieving this goal is the use of low dimensional structures such as quantum wells, quantum dots, superlattices (SL) and nanolaminates to affect heat transport. SL structures can effectively confine charge carriers as well as scatter phonons which contribute significantly to thermal conductivity. …

Design And Construction Of A Reconfigurable Pilot-In-The-Loop Aircraft Simulation Workstation, John J. Miller

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis presents and explains the methodology used to design and construct an aircraft dynamics simulation workstation. Beginning from an outdated Navy T-34 training simulator, a gift to the school by the Naval Aerospace Medical Research Laboratory via a previous student, a new system was created to allow an engineer and/or pilot to manually control and evaluate vehicle characteristics for the purposes of research, development, and testing. Retaining only the superstructure of the original T-34 trainer, the entire system was re-engineered to provide a functional, immersive, and expandable simulation environment, complete with a five-screen visual system covering 97.5 deg of …

Spatial Visualization Ability And Impact Of Drafting Models: A Quasi Experimental Study, Petros J. Katsioloudis, Vukica Jovanovic

STEMPS Faculty Publications

A quasi experimental study was done to determine significant positive effects among three different types of visual models and to identify whether any individual type or combination contributed towards a positive increase of spatial visualization ability for students in engineering technology courses. In particular, the study compared the use of different visual models - a 3D printed solid object, a 3D computer generated drawing and a 2D drawing.

Simulation Modeling And Analysis Of Customs-Regulated Container Terminal Operations With Multimodal Transportation, Mariam A. Kotachi

Engineering Management & Systems Engineering Theses & Dissertations

World trade has been increasing dramatically in the past two decades and, as a result, container exchange has grown significantly. Consequently and to meet this increase, several container terminals are expanding and many new ones are being established. A port with one or more container terminals is considered a complex system in which many entities interact to accomplish seamless handling of containers inbound and outbound. The level of complexity is drastically heightened for container terminals containing multimodal transportation systems as they typically involve ships, rail, and trucks arriving to one or more terminals delivering containers of different sizes to several …

Web Archive Services Framework For Tighter Integration Between The Past And Present Web, Ahmed Alsum

Computer Science Theses & Dissertations

Web archives have contained the cultural history of the web for many years, but they still have a limited capability for access. Most of the web archiving research has focused on crawling and preservation activities, with little focus on the delivery methods. The current access methods are tightly coupled with web archive infrastructure, hard to replicate or integrate with other web archives, and do not cover all the users' needs. In this dissertation, we focus on the access methods for archived web data to enable users, third-party developers, researchers, and others to gain knowledge from the web archives. We build …

An Initial Look At Robotics-Based Initiatives To Engage Girls In Engineering, Jennifer Michaeli, Vukica Jovanovic, Otilia Popescu, Ana Djuric, Ece Yaprak

Engineering Technology Faculty Publications

Over the past 10 years, the use of robotic kits in K-12 Science, Technology, Engineering, and Math (STEM) initiatives as well as undergraduate engineering education has increased significantly. However, a survey of students in grades 9–12 indicated that only 2–3% of women in high school express an intention to study engineering; conversely, 16% of high school men declared that they plan to pursue an engineering degree [1]. In this paper, the authors present an initial review of published literature regarding the use of robotics in schools to identify cases where robotic kits have been used to engage girls in STEM …

State Variable Model For Unsteady Two Dimensional Axial Vortex Flow With Pressure Relaxation, Mazin Mohammed Elbakri Abuharaz

Mechanical & Aerospace Engineering Theses & Dissertations

This research has utilized a state variable model for unsteady two dimensional axial vortex flows experiencing non-equilibrium pressure gradient forces. The model was developed successfully using perturbed radial and azimuthal momentum equations and a pressure Poisson's equations. Three main regions of the axial vortex flow were highlighted in this study including: a laminar core region, a non-equilibrium pressure envelope, and an outer potential vortex.

Linear stability theory was utilized to formulate the model and the perturbation functions were assumed to be of the Fourier type. The flow parameters considered were the Reynolds numbers, ranging between 6,000 and 14,000, and a …

Systems Theory Based Framework For Competency Models, Joseph M. Bradley

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to develop and apply a systems theoretic framework for design, analysis and transformation of competency models using an inductive research design. This research examines the origins and development of competency models from a systems theoretic perspective. Competency models have been largely developed by a comparative method first proposed by McClelland, or the use of Delphi method survey techniques. The assumption that a population containing an exemplar and fully successful members would enable population of a holistic competency model has reported numerous failures. Similarly, reporting on the use of Delphi methods has focused on attempting …

An Investigation Into The Analysis Of Truncated Standard Normal Distributions Using Heuristic Techniques, John Walter Ralls

Engineering Management & Systems Engineering Theses & Dissertations

Standard normal distributions (SND) and truncated standard normal distributions (TSND) have been widely used and accepted methods to characterize the data sets in various engineering disciplines, financial industries, medical fields, management, and other mathematic and scientific applications. For engineering managers, risk managers and quality practitioners, the use of the standard normal distribution and truncated standard normal distribution have particular relevance when bounding data sets, evaluating manufacturing and assembly tolerances, and identifying measures of quality. In particular, truncated standard normal distributions are used in areas such as component assemblies to bound upper and lower process specification limits.

This dissertation presents a …

Characterization Of An Impulse Radiating Antenna In The Near Field, Chandra Barjracharya

Electrical & Computer Engineering Theses & Dissertations

The biological effects of intense sub-nanosecond pulses on tissues or cells are in the dielectric domain and not based on thermal loading as in the conventional microwave radiation, which may lead to an entirely new approach of modifying cell functions. Moreover, the resulting cell functional change may be detected with higher resolution by broadband, sub-nanosecond pulses than conventional narrowband systems. The delivery of intense sub-nanosecond pulses to near-field biological tissues, however, has not been studied, not mentioning the focal depth and volume. In this dissertation, for the first time, an impulse radiating antenna with a balanced feed structure is studied …

Assessing The Impact Of Electronic Health Record Systems Implementation On Hospital Patient Perceptions Of Care, Katherine Sofia Palacio Salgar

Engineering Management & Systems Engineering Theses & Dissertations

The delivery of health care services has been impacted by advances in Knowledge Management Information Systems (KMIS) and Information Technology (IT). The literature reveals that Electronic Health Records Systems (EHRs) are a comprehensive KMIS. There is a wide recognition in the body of knowledge that demonstrates the potential of EHRs to transform all aspects of health care services and, in consequence, the performance of Health Care Delivery Organizations (HCDO). Authors of published research also agree that there is a need for more empirical contributions that demonstrate the impact of EHRs upon HCDO. It is argued that in most cases, studies …

System Identification Of An Autonomous Surface Vehicle, Christopher John Cook

Mechanical & Aerospace Engineering Theses & Dissertations

The modeling and system identification of a small pontoon based marine craft, without rudder control, in a controlled environment. Old Dominion University's autonomous surface vehicle was modeled using the Observer/Kalman System Identification method. The experimental position data was collected using a laser positioning system along with Arduino based sensors on board the boat to collect the motor speeds of the dual outboard motors. The data was then compiled using the System/ Observer/Controller Identification Toolbox to derive a dynamic model that is capable of providing path estimation and prediction information to the autonomous robotic system.

Assessing Organizational Effectiveness Through The Competing Values Framework A Data Envelopment Approach, Raghavender Macherla

Engineering Management & Systems Engineering Theses & Dissertations

This study proposes a model to diagnose organizations using the mathematical principles of data envelopment analysis (DEA) to the variables generated using competing values framework (CVF) in order to evaluate overall organizational effectiveness. The notion of organizational effectiveness is abstract and difficult to measure due to its complexity and multi-functional nature. Over the years, measurement of organizational effectiveness has remained a challenge due to the lack of agreement on the factors that should be assessed to determine effectiveness. This research is aimed at shedding some light into this topic by using data envelopment analysis as a tool to measure relative …