Engineering Commons^™

Collision Response Of Surface Modeled Organs For Virtual Laparoscopic Surgery, Dibbesh Sharma Adhikari

Electrical Engineering Theses - Archive

Laparoscopic surgery is a modern surgical procedure in which, operations are performed in the abdomen by monitoring the image from a laparoscope: a telescopic rod lens system, which is usually connected to a video camera with a halogen or xenon light source, and is inserted into the abdomen through a small incision. Generally, laparoscopic surgeries are chosen over open surgery because of lower pain and speedier recovery process. However, the surgeon needs additional training in performing such surgery since laparoscopic camera reflects 2D mirror image of hand movement and depth information of the scene is harder for the surgeon to …

Collision Detection And Penetration Depth Calculation In Virtual Surgical Simulation, Rupin Pavithran

Electrical Engineering Theses - Archive

Virtual Reality (VR) based surgical simulators create a simulated, realistic three dimensional surgical environments using advanced graphic and haptic rendering techniques. Virtual objects, which are geometric surface polygonal models of different human organs and instruments, are rendered in a common viewing volume. Such deformable or non-deformable polygonal models interact with each other. In order to provide a realistic response in real-time, detection of collisions in such models is the greatest challenge in the field of VR based simulators. Once collision is detected, the overlapping region and the largest penetration distance for a pair of intersecting objects need to be determined …

The Design Of A Precision Current Miror Using A High-Gain Current Amplifier, Mei-Ping Pua

Electrical Engineering Theses - Archive

An improved high gain, precision, low sensitivity current mirror is designed around a feedback circuit. This mirror utilizes a buffered Widlar current mirror to drive the constant input reference current, two beta helpers to compensate for the loss of base current and an active load, and a feedback loop in the amplifier. This design provides a comparison node for detecting the input error signal. The output collector current is substantially equal to the input reference current when driving multiple transistor loads. The circuit has been fabricated with National's VIP10 process, which caters to the high gain bipolar technology. Measurement results …

Development Of A New Procedure For Assessing Power System Reliability In Preparation For Nerc's Standards Compliance, Frederico Von Pinho

Electrical Engineering Theses - Archive

In response to historical reliability issues of the past and following the evolution of newly developing power system markets, NERC has created new standards for maintaining and enforcing power system reliability. Entities are still reviewing the standards and finding ways to comply with the same. Non-compliance can result in financial penalties that can add-up to $1M per day per violation.The aim of this thesis is to propose a procedure to be followed by entities wishing to comply with NERC's reliability requirements for a preliminary determination/understanding of the current reliability situation of the system and therefore foresee any difficulties might appear …

Evaluation Of Iso 18000-6 Type C Class 1 Generation 2 Rfid Protocol Artifacts, Nikhil Ayer

Electrical Engineering Theses - Archive

In this thesis, we have identified the effect on the performance of the RFID system when ISO 18000-6 Class 1 Gen 2 RFID protocol's parameters are changed. The protocol parameters we considered changing for the conformance testing are Tari, operating frequency, pulse width and modulation index at the constant transmitted power. The range of frequencies used in the experiments does fall outside the specification of ISO 18000-6 Type-C Class-1 Gen-2 protocol; but the power transmited by the RFID reader is under the FCC regulations. The research gives the detail behavior of the RFID signal propagation both from the reader to …

Fabrication Of Complex 3d Micro-Scale Scaffolds And Drug Delivery Devices Using Dynamic Mask Projection Microstereolithography, Jae-Won Choi, In-Baek Park, Ryan B. Wicker, Seok-Hee Lee, Ho-Chan Kim

Mechanical Engineering Faculty Research

Microstereolithography (μSL) technology can fabricate three-dimensional (3D) tissue engineered scaffolds with controlled biochemical and mechanical micro-architectures. A μSL system for tissue engineering was developed using a Digital Micromirror Device (DMDTM) for dynamic pattern generation and an ultraviolet (UV) lamp filtered at 365 nm for crosslinking the photoreactive polymer solution. The μSL system was designed with x-y resolution of ~2 μm and a vertical (z) resolution of ~1 μm. To demonstrate the use of μSL in tissue engineering, poly(propylene fumarate) (PPF) was synthesized with a molecular weight of ~1200 Da. The viscosity of the PPF was reduced to ~150 cP (at …

A Simulation-Based Approach For Dock Allocation In A Food Distribution Center, Balagopal Gopakumar, Suvarna Sundaram, Shengyong Wang

Mechanical Engineering Faculty Research

This research endeavor focused on the warehouse receiving process at a large food distribution center, which comprises of trucks with goods reaching the destination warehouse, unloading and finally putting away the contents to the specific aisles. Discrete event simulation was used to model the current system’s functioning and to identify operational inefficiencies which were quantified through a detailed value stream mapping exercise. Inspired by ‘lean’ philosophy, a dock allocation algorithm was designed to take into account the relationship between the dock location and the destination aisle to ‘optimally’ assign the trucks to the docks. After validating the baseline, new scenarios …

An Evaluation Of A Stem Program For Middle School Students On Learning Disability Related Ieps, Paul C. Lam, Dennis Doverspike, Julie Zhao, Jiang Zhe, Craig C. Menzemer

Mechanical Engineering Faculty Research

A year long Science, Technology, Engineering and Math (STEM) program was developed for middle schools students on Individualized Education Programs (IEPs) involving learning disabilities. The workshops were designed to encourage students both on IEPs and not on IEPs to explore STEM as a future career choice by building their knowledge and confidence. The participants in the workshops included 11 students on IEPs and 15 students not on IEPs. Parents also provided feedback regarding their attitudes toward the program. The results indicated that there were increases in student participant knowledge and career interest for both the students not on IEPs and …

Differences In The Performance Of Knowledge Transfer Across Projects: A Study Of Gender And Role Of Key Project Stakeholders, Rafael E. Landaeta, Catherine Vergopia, Rey N. Diaz

Engineering Management & Systems Engineering Faculty Publications

This investigation contributes empirical results of differences identified in key project stakeholders with respect to their use of knowledge transferred across projects. Gender and role were the two individual characteristics investigated. Project managers and members of project teams were the key stakeholders analyzed. Data was collected from 71 closed projects using a survey composed of closed-ended questions. The data collected was cross tabulated and statistically analyzed using Friedman's test and Spearman's correlation. The results provide evidence of the association of the performance of knowledge transfer across projects with (a) the individual factors of gender and role of key project stakeholders …

Evaluation Of The Effectiveness Of Pavement Rumble Strips, Adam Kirk

Kentucky Transportation Center Research Report

This report analyzes the effectiveness of continuous shoulder rumble strips (CSRS) and center line rumble strips (CLRS) on rural two lane roads in Kentucky. This study evaluates the safety benefits, and design details associated with the application of the CSRS and CLRS. The recommended practices proposed as a result of the crash analysis have the potential to reduce both run off the road and opposite direction crashes on rural two lane roads in Kentucky. These recommendations provide benefits for narrow roadways with little to no shoulder as well as larger roadways with wider paved shoulders.

Use Of Edge Line Markings On Rural Two-Lane Highways, Kenneth R. Agent, Eric R. Green

Kentucky Transportation Center Research Report

The objective of this study was to review roadway characteristics and crash data in Kentucky and determine if revisions should be made to current guidelines for the use of edge lines. Recommendations were made concerning the use of edge lines, centerlines, and paved shoulders on rural, two-lane roadways with varying pavement widths.

Quantitative Characterization Of Resistive Defects In Thick Composites Using Step Heating Thermography, Adel A. Badghaish, David C. Fleming

Aerospace, Physics, and Space Science Faculty Publications

Inspection of thick composite structures, such as Reinforced Thermosetting Resin (RTR) pipes used in the petroleum industry, using infrared thermography is difficult. This paper investigates the use of step heating thermography to increase the maximum detectable defect depth and describes techniques to quantitatively characterize defect depth and severity in thick composites. A procedure to simultaneously determine defect depth and thermal resistance from the early time surface temperature is described. The procedure is based on fitting the early time surface temperature profile over a defect to a one-dimensional three-layer analytical model. Experimental testing demonstrates the accuracy of the procedure.

A Separation Criterion And Non-Intrusive Thickness Measurement Technique For Shear-Driven Films, Mark A. Friedrich

Masters Theses

"The behavior of a shear-driven thin liquid film at a sharp expanding corner is of interest in many engineering applications. However, details of the interaction between inertial, surface tension, and gravitational forces at the corner that result in partial or complete separation of the film from the surface are not clear. The focus of this study was to develop a criterion to predict the onset of shear-driven film separation from the surface at an expanding corner as well as to develop a film thickness measurement technique that could be used to obtain an average film thickness for input into the …

Correlating Degradation Models And Image Quality Metrics, Darrin K. Reed, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

OCR often performs poorly on degraded documents. One approach to improving performance is to determine a good filter to improve the appearance of the document image before sending it to the OCR engine. Quality metrics have been measured in document images to determine what type of filtering would most likely improve the OCR response for that document image. In this paper those same quality metrics are measured for several word images degraded by known parameters in a document degradation model. The correlation between the degradation model parameters and the quality metrics is measured. High correlations do appear in many places …

Multi-View Approaches To Tracking, 3d Reconstruction And Object Class Detection, Saad Khan

Electronic Theses and Dissertations

Multi-camera systems are becoming ubiquitous and have found application in a variety of domains including surveillance, immersive visualization, sports entertainment and movie special effects amongst others. From a computer vision perspective, the challenging task is how to most efficiently fuse information from multiple views in the absence of detailed calibration information and a minimum of human intervention. This thesis presents a new approach to fuse foreground likelihood information from multiple views onto a reference view without explicit processing in 3D space, thereby circumventing the need for complete calibration. Our approach uses a homographic occupancy constraint (HOC), which states that if …

Design Of Polynomial-Based Filters For Continuously Variable Sample Rate Conversion With Applications In Synthetic Instrumentati, Matthew Hunter

Electronic Theses and Dissertations

In this work, the design and application of Polynomial-Based Filters (PBF) for continuously variable Sample Rate Conversion (SRC) is studied. The major contributions of this work are summarized as follows. First, an explicit formula for the Fourier Transform of both a symmetrical and nonsymmetrical PBF impulse response with variable basis function coefficients is derived. In the literature only one explicit formula is given, and that for a symmetrical even length filter with fixed basis function coefficients. The frequency domain optimization of PBFs via linear programming has been proposed in the literature, however, the algorithm was not detailed nor were explicit …

Improving Branch Prediction Accuracy Via Effective Source Information And Prediction Algorithms, Hongliang Gao

Electronic Theses and Dissertations

Modern superscalar processors rely on branch predictors to sustain a high instruction fetch throughput. Given the trend of deep pipelines and large instruction windows, a branch misprediction will incur a large performance penalty and result in a significant amount of energy wasted by the instructions along wrong paths. With their critical role in high performance processors, there has been extensive research on branch predictors to improve the prediction accuracy. Conceptually a dynamic branch prediction scheme includes three major components: a source, an information processor, and a predictor. Traditional works mainly focus on the algorithm for the predictor. In this dissertation, …

Design Stability For Concept Selection, Vivek K. Jikar, Kenneth M. Ragsdell

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper re-visits the concept of Design Stability proposed earlier. It further develops a new metric called the Design Stability Coefficient for use in the concept selection stage during early phases of new product development. Design Stability Coefficient is analyzed qualitatively as well as quantitatively and developed as an objective criterion for selecting the best alternative for realizing high value for the end-user of a product. a Wheatstone Bridge is used as an example to indicate a procedure for computing the Design Stability Coefficient. Calculated values are compared with the Nominal the Best signal to noise ratio. Copyright © 2008 …

Il-21 Limits Peripheral Lymphocyte Numbers Through T Cell Homeostatic Mechanisms., Shrimati Datta, Nora E. Sarvetnick

Journal Articles: Regenerative Medicine

BACKGROUND: IL-21, a member of the common gamma-chain utilizing family of cytokines, participates in immune and inflammatory processes. In addition, the cytokine has been linked to autoimmunity in humans and rodents.

METHODOLOGY/PRINCIPAL FINDINGS: To investigate the mechanism whereby IL-21 affects the immune system, we investigated its role in T cell homeostasis and autoimmunity in both non-autoimmune C57BL/6 and autoimmune NOD mice. Our data indicate that IL-21R knockout C57BL/6 and NOD mice show increased size of their lymphocyte population and decreased homeostatic proliferation. In addition, our experimental results demonstrate that IL-21 inhibits T cell survival. These data suggest that IL-21 acts …

Gas Sensing Properties And Transport Properties Of Multi Walled Carbon Nanotubes, Raghu Mangu

University of Kentucky Master's Theses

Multi walled carbon nanotubes (MWCNT) grown in highly ordered porous alumina templates were incorporated into a resistive gas sensor design and were evaluated for their sensitivities. The material characteristics and electrical properties of the nanotubes were analyzed. A study was undertaken to elucidate the effect of UV light on desorption characteristics and the dependence of sensitivity on (i) thickness of amorphous carbon layers and (ii) flow rates of analyte gases. These sensors were highly responsive to both oxidizing and reducing gases with steady state sensitivities of 5% and 10% for 100ppm of NH₃ and NO₂ respectively, at room …

Implementing An Architectural Framework To Define And Deliver Net-Centric Capability To Legacy Military Air Assets Operating Within A System Of Systems, Mark S. Anderson, S. M. Martin, Cihan H. Dagli, Ann K. Miller

Engineering Management and Systems Engineering Faculty Research & Creative Works

The United States Air Force (USAF) is implementing an integrated net-centric system of systems for airborne operations in support of the global war on terror (GWOT). The GWOT demands that a successful architecture framework transforms and delivers net-centric assets to the war-fighter in a timely manner. A critical component of this implementation is the transformation of legacy strategic air platforms into net-centric air power assets operating within a system of systems. The System Architectural (SA) framework, and the Department of Defense Architectural Framework (DoDAF) are ways of managing complexity and organizing information within a system of systems network. This paper …

Computer Simulation Of Radio Frequency Heating Of Model Fruit Immersed In Water, Sohan Birla, Shaojin Wang, Juming Tang

Department of Engineering Mechanics: Faculty Publications

The present study investigated the effect of different factors on temperature distribution within a spherical object in a parallel plate radio frequency (RF) heating system. A finite element-computer simulation program - FEMLAB was used to solve the electromagnetic and Navier-Stoke equations for developing a model to study the effect of dielectric properties of a model fruit and its surrounding medium. The model fruit was prepared from 1% gellan gel for experimental validation of the simulation results. The results showed that spherically-shaped samples surrounded with air between RF electrodes and placed in the proximity of electrodes would not heat uniformly. Immersing …

Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan

Theses

Communication systems are undergoing constant and rapid innovation, both at the design stage and in the field. This in turn has led to an inereasing need for fast, efficient, portable and economic methods for the testing of these systems. For voice carrying communication systems the quality of the transmitted voice that the system produces is a large factor in the overall performance rating of the system. This measure is known as the ‘Quality of Voice’ (QoV) and can be evaluated either subjectively or objectively.

Speech quality is a complex subjective phenomenon that can be best quantified by subjective testing. A …

Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik

Mechanical Engineering Faculty Publications

Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of Reinforcement Learning to create a controller that can adapt to these
changing dynamics of a human arm. Development and tests were done in simulation using a two-dimensional arm model and Hill-based muscle dynamics. An actor-critic architecture is used with artificial neural networks for both the actor and the critic. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant …

Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg

Mechanical Engineering Faculty Publications

The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase …

Statistical Approach To The Development Of A Microscale Model For Estimating Exhaust Emissions Of Light Duty Gasoline Vehicles, Benjamin Nmai Afotey

Civil Engineering Dissertations - Archive

Today, air pollution is taking a growing toll on human health, the environment and the economy, despite decades of efforts to combat it. Although it was once a primary urban phenomenon in industrialized countries, today air pollution has spread worldwide. Mobile, industrial and natural sources constitute the major sources of air pollution. Around the world, major cities in industrialized countries have in recent times been battling air pollution from mobile sources. Beijing, New Delhi, Dallas/ Fort Worth and Los Angeles are no exceptions.Pronounced interest has focused on mobile source (vehicle exhaust) emissions in recent decades. A rapid increase in the …

Multi-Criteria Assessment For Supporting Freeway Operations And Management Systems, Auttawit Upayokin

Civil Engineering Dissertations - Archive

Freeway traffic congestion represents an increasing concern for urban areas throughout the United States. In addition, faced with limited roadway expansion alternatives, transportation agencies are considering investment in traffic management centers (TMCs) as a more viable way to operate and manage freeways effectively. The TMCs' responsibilities include monitoring roadway conditions using the various data collection strategies and determining performance measures for freeway operations. At the same time, traffic engineers at the TMCs may react to the traffic congestion problems by implementing operational strategies. In order to provide reliable decision support for TMC freeway operations and management systems, this dissertation aims …

A Surface Inspection Machine Vision System That Includes Fractal Texture Analysis, Jonathan Blackledge, Dmitry Dubovitskiy

Articles

The detection, recognition and classification of features in a digital image is an important component of quality control systems in production and process engineering and industrial systems monitoring, in general. In this paper, a new pattern recognition system is presented that has been designed for the specific task of monitoring the quality of sheet-steel production in a rolling mill. The system is based on using both the Euclidean and Fractal geometric properties of an imaged object to develop training data that is used in conjunction with a supervised learning procedure based on the application of a fuzzy inference engine. Thus, …

Feasibility Study Of An Ultra Fast Gated Camera To Image Biliary Tree Embedded In Adipose Tissue Using Laboratory Phantoms And Monte Carlo Simulations, Nimit Lalitkumar Patel

Bioengineering Theses - Archive

Every year, approximately 500,000 cholecystectomies are performed in US. As biliary tree structures are embedded in adipose tissue, they cannot be visualized directly by the surgeon, which causes inadvertent injuries to the common bile duct, vein and artery during a laparoscopic cholecystectomy. Thus there is an urge for an imaging modality which could see biliary tree structure through fatty tissue. Successful clinical implementation of an imaging system which could attain this goal would reduce surgical time, improve patient safety and minimize the risk of complications and expenses attributable to the current standard practice of intraoperative cholecystectomy. It is hoped that …

Automated Quantification Of White Matter Hyperintensity Burden Using Mprage And Flair Images From A Large Population, Keith Mcleod Hulsey

Bioengineering Theses - Archive

White Matter Hyperintensity(WMH) burden, as observed in T2 and proton weighted MR images, is associated with several health factors such as decreased cognitive ability, hypertension, diabetes and cerebrovascular disease. An algorithm was developed to automatically estimate WMH burden from pairs of MPRAGE and FLAIR images which is robust and requires essentially no operator involvement. The WMH burden estimation generated by this fully automated algorithm has been shown to correlate well with known risk factors for WMH burden.