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Full-Text Articles in Engineering

Voltage Stability Indices Based On Active Power Transfer Using Synchronized Phasor Measurements, Rui Sun Dec 2009

Voltage Stability Indices Based On Active Power Transfer Using Synchronized Phasor Measurements, Rui Sun

All Theses

In recent years and in the foreseeable future, power demands generally around the world and particularly in North America will experience rapid increases due to the increase of customers' requirements, while the development of transmission systems in North America is rather slow. Voltage stability assessment becomes one of the highest priorities to power utilities in North America. Voltage stability index is a feature for solving voltage stability problems. It is generated from the basic power flow equations and/or energy functions. The mathematical expression of a VSI is often written as a polynomial containing the systems real-time measurements such as voltage …


Modeling The Cooling Phase Of The Lens Molding Process, Saravanan Kannan Dec 2009

Modeling The Cooling Phase Of The Lens Molding Process, Saravanan Kannan

All Theses

The lens molding process is a relatively new technique used to manufacture lenses, in particular, high precision aspheric lenses. In order to achieve the desired size and shape of the lens, the cooling process after pressing must be controlled precisely because of the time and temperature dependent viscoelastic behavior of glass near and below the molding temperature. This thesis gives a detailed description of a three-dimensional computational model for analyzing the cooling phase of the lens molding process. Conduction, convection and radiation are considered in the model by coupling a computational fluid dynamics analysis of the flow of nitrogen through …


Interactive Perception For Cluttered Environments, Robert Willimon Dec 2009

Interactive Perception For Cluttered Environments, Robert Willimon

All Theses

Robotics research tends to focus upon either non-contact sensing or machine manipulation, but not both. This paper explores the benefits of combining the two by addressing the problem of extracting and classifying unknown objects within a cluttered environment, such as found in recycling and service robot applications. In the proposed approach, a pile of objects lies on a flat background, and the goal of the robot is to sift through the pile and classify each object so that it can be studied further. One object should be removed at a time with minimal disturbance to the other objects. We propose …


A Voltage Flicker Suppression Device For Residential Air Conditioners And Heat Pumps, John Fox Dec 2009

A Voltage Flicker Suppression Device For Residential Air Conditioners And Heat Pumps, John Fox

All Theses

In some circumstances, voltage flicker due to the inrush current of residential heat pump can be a fairly visible to the residents as a slight flashing of the household's lights during the compressor starting event. The voltage flicker problem is caused by a variable contribution from sizable equivalent power system impedances and considerable inrush currents drawn by compressors. While this is not a new problem, and there are technologies on the market that attempt to alleviate the voltage flicker issue, no current solution attempts to correct for the problem at its root cause.
This thesis presents a device designed to …


Identifying The Optimum Process Parameters Of Precision Glass Molding For Aspherical Lenses, Waqas Iqbal Dec 2009

Identifying The Optimum Process Parameters Of Precision Glass Molding For Aspherical Lenses, Waqas Iqbal

All Theses

The purpose of this research is to determine the optimum process parameters for the Precision Glass Molding (PGM) Process using Manufacturing Design, Design of Experiments and Metrology (for measuring the geometry of lenses). First, a custom machine is designed and manufactured which can carry out Precision Glass Lens Molding Experiments. This machine is then modified to improve temperature, position and force control. A literature review is performed to obtain data for process parameters that have been used in previous PGM studies. The collected data is then used in Design of Experiments to create twenty seven experiments that determine the optimum …


Identifying And Comparing Key Process Attributes For Sustainable Building Delivery In India And The U.S., Prashanth Palanisamy Dec 2009

Identifying And Comparing Key Process Attributes For Sustainable Building Delivery In India And The U.S., Prashanth Palanisamy

All Theses

India is a rapidly developing nation with the associated brisk pace of construction. More sustainable building practices for construction in India would have social, environmental, and economic benefits. However, the key process attributes for successfully planning, designing, and constructing sustainable buildings in India are largely undefined. Other projects in India would benefit from a rigorous identification of these key process attributes which could help leapfrogging the sustainable building delivery in India to the best available practices.
Sustainable buildings require different delivery processes than traditional buildings; this can lead to process wastes due to unfamiliarity or incompatibility of the processes. These …


Evaluation Of An Online Intelligent Transportation System (Its) Asset Management System, Tahera Anjuman Dec 2009

Evaluation Of An Online Intelligent Transportation System (Its) Asset Management System, Tahera Anjuman

All Theses

Intelligent Transportation System (ITS) enhances the performance of modern transportation systems by improving the reliability of travel times and reducing the risk of collisions and injuries. Recently, many public agencies have expressed a need for an ITS asset management system that will effectively and efficiently meet their requirements of managing associated resources, which often includes technologically sophisticated devices, computer hardware and software, and communications infrastructure. To address this need, the author evaluated different asset management systems for their potential efficacy to support public agencies requirements for an ITS asset management system. These requirements were identified through a nationwide survey of …


Vibrations Of Thin Plate With Piezoelectric Actuator: Theory And Experiments, Parikshit Mehta Dec 2009

Vibrations Of Thin Plate With Piezoelectric Actuator: Theory And Experiments, Parikshit Mehta

All Theses

Vibrations of flexible structures have been an important engineering study owing to its both deprecating and complimentary traits. These flexible structures are generally modeled as strings, bars, shafts and beams (one dimensional), membranes and plate (two dimensional) or shell (three dimensional). Structures in many engineering applications, such as building floors, aircraft wings, automobile hoods or pressure vessel end-caps, can be modeled as plates. Undesirable vibrations of any of these engineering structures can lead to catastrophic results. It is important to know the fundamental frequencies of these structures in response to simple or complex excitations or boundary conditions.
After their discovery …


Charging Kinetics Of Electric Double Layer Capacitors, Clint Cagle Dec 2009

Charging Kinetics Of Electric Double Layer Capacitors, Clint Cagle

All Theses

A recent increase in the popularity of EDLCs and AC-EOF has necessitated a deeper understanding of the structure and charging kinetics of electrical double layers (EDLs) at electrode-electrolyte interfaces. Here, the charging kinetics of EDLs in nanoscale EDLCs is studied by a circuit model, a Poisson-Nernst-Planck (PNP) mo del, and molecular dynamics (MD) simulations. The results of the MD simulations demonstrate a linear charging behavior of EDLs near planar electrodes for both aqueous and organic electrolytes at charging below 90% and time larger than tens of picoseconds. Additionally, we will show that the circuit and PNP models are capable of …


The Development Of A Mechatronics And Material Handling Course: Laboratory Experiments And Projects, James Shirley Dec 2009

The Development Of A Mechatronics And Material Handling Course: Laboratory Experiments And Projects, James Shirley

All Theses

Mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging industrial problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems, because of their use of programmable logic controllers (PLC), PLC networks, industrial robotics, and other mechatronic elements, are a natural choice for a college instructional environment. This thesis offers insight and guidance for mechatronic activities introduced in a laboratory setting. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize …


The Design Of An Ic Half Precision Floating Point Arithmetic Logic Unit, Balaji Kannan Dec 2009

The Design Of An Ic Half Precision Floating Point Arithmetic Logic Unit, Balaji Kannan

All Theses

A 16 bit floating point (FP) Arithmetic Logic Unit (ALU) was designed and implemented in 0.35µm CMOS technology. Typical uses of the 16 bit FP ALU include graphics processors and embedded multimedia applications.
The ALU of the modern microprocessors use a fused multiply add (FMA) design technique. An advantage of the FMA is to remove the need for a comparator which is required for a normal FP adder. The FMA consists of a multiplier, shifters, adders and rounding circuit. A fast multiplier based on the Wallace tree configuration was designed. The number of partial products was greatly reduced by the …


Relationships Between Lane Change Performance And Open-Loop Handling Metrics, Robert Powell Dec 2009

Relationships Between Lane Change Performance And Open-Loop Handling Metrics, Robert Powell

All Theses

This work deals with the question of relating open-loop handling metrics to driver-in-the-loop performance (closed-loop). The goal is to allow manufacturers to reduce cost and time associated with vehicle handling development. A vehicle model was built in the CarSim environment using kinematics and compliance, geometrical, and flat track tire data. This model was then compared and validated to testing done at Michelin's Laurens Proving Grounds using open-loop handling metrics. The open-loop tests conducted for model validation were an understeer test and swept sine or random steer test. Four commonly used handling metrics (steady state yaw rate gain, yaw rate damping …


Friction Stir Welding Process And Material Microstructure Evolution Modeling In 2000 And 5000 Series Of Aluminum Alloys, Harshavardhan Yalavarthy Dec 2009

Friction Stir Welding Process And Material Microstructure Evolution Modeling In 2000 And 5000 Series Of Aluminum Alloys, Harshavardhan Yalavarthy

All Theses

Interactions between the rotating and advancing pin-shaped tool (terminated at one end with a circular-cylindrical shoulder) with the clamped welding-plates and the associated material and heat transport during a Friction Stir Welding (FSW) process are studied computationally using a fully-coupled thermo-mechanical finite-element analysis. To surmount potential numerical problems associated with extensive mesh distortions/entanglement, an Arbitrary Lagrangian Eulerian (ALE) formulation was used which enabled adaptive re-meshing (to ensure the continuing presence of a high-quality mesh) while allowing full tracking of the material free surfaces. To demonstrate the utility of the present computational approach, the analysis is applied to the cases of …


Principal Component Thermography For Steady Thermal Perturbation Scenarios, Rohit Parvataneni Dec 2009

Principal Component Thermography For Steady Thermal Perturbation Scenarios, Rohit Parvataneni

All Theses

The work focuses on the qualitative enhancement of Thermographic Inspection data using Principal Component Analysis technique. A new processing tool named Economical Singular Value Decomposition (SVD) is proposed for analyzing the infrared image sequences acquired from the test specimen.
Experiments are carried out on test sample using thermal excitation modalities such as flash, halogen and induction to create temperature variations. The infrared (IR) image sequence containing the information about the sample is captured using IR cameras. The acquired IR image sequences are processed using the proposed Economical SVD which projects the matrix of raw pixel values of image sequence into …


Neomycin Enhances Glutaraldehyde Crosslinking And Glycosaminoglycan Stability In Bioprosthetic Heart Valves, Vincent Friebe Dec 2009

Neomycin Enhances Glutaraldehyde Crosslinking And Glycosaminoglycan Stability In Bioprosthetic Heart Valves, Vincent Friebe

All Theses

The native heart valve will open and close an astonishing 3 billion times in the average lifetime, implicating immense biomechanical ramifications that necessitate near-flawless structure and functional behavior. Deviations from this idyllic function as a result of heart valve disease (HVD) affect millions of individuals worldwide and result in over 275,000 heart valve replacements worldwide every year. Glutaraldehyde (GLUT) cross-linked porcine aortic heart valves, a common type of bioprosthetic heart valve (BHV), are used frequently in these valve replacement surgeries. The native valve leaflets entail a tri-composite design of type I collagen, elastin and glycosaminoglycans (GAGs), each of which are …


Experimental Characterization Of Stress Relaxation In Glass, Hemanth Kadali Dec 2009

Experimental Characterization Of Stress Relaxation In Glass, Hemanth Kadali

All Theses

Glass viscoelasticity has gained importance in recent years as glass lens molding appeared as a valuable alternative to the traditional grinding and polishing process for manufacturing glass lenses. In the precision lens molding process, knowledge of viscoelastic properties of glass in the transition region, which affect the stress relaxation behavior, is required to precisely predict the final size and shape of molded lenses. The purpose of this study is to establish a step-by-step procedure for characterizing the viscoelastic behavior of glass in the glass transition region using a finite term Prony series of a Generalized Maxwell model. This study focuses …


A Logistic Regression Model To Predict Incident Severity Using The Human Factors Analysis And Classification System, Hrishikesh Kavade Dec 2009

A Logistic Regression Model To Predict Incident Severity Using The Human Factors Analysis And Classification System, Hrishikesh Kavade

All Theses

The Human Factors Analysis and Classification System (HFACS) is used to help identify causal factors that lead to human error. The framework has been used in a variety of industries to identify leading contributing factors of unsafe events, such as accidents, incidents and near misses. While traditional application of the HFACS framework to safety outcomes has allowed evaluators to identify leading causal issues based on frequency, little has been done to gain a more comprehensive view of the system's total risk. This work utilizes the concept of event severity along with the HFACS framework to help better identify target areas …


Sensor-Based Soil Water Monitoring To More Effectively Manage Agricultural Water Resources In Coastal Plain Soils, Christopher Bellamy Dec 2009

Sensor-Based Soil Water Monitoring To More Effectively Manage Agricultural Water Resources In Coastal Plain Soils, Christopher Bellamy

All Theses

Cotton (Gossypium hirsutum L.) is widely grown in the United States with 5.7 million ha grown nationally and 1.2 million ha grown in the humid southeastern states in 2005. From 1969 to 2003, agricultural irrigated farmland acreage and total water applied increased by over 40% and 11% respectively to include a total of 55.3 million acres in 2002. Combined with recent and more frequent drought periods and legal water conflicts between states, there has been an increased interest in more effective southeastern water management, thus making the need to develop improved irrigation scheduling methods and enhanced water use efficiency of …


Design And Analysis Of Alternating Spoke Pair Concepts For A Non-Pneumatic Tire With Reduced Vibration At High Speed Rolling, Shashank Bezgam Dec 2009

Design And Analysis Of Alternating Spoke Pair Concepts For A Non-Pneumatic Tire With Reduced Vibration At High Speed Rolling, Shashank Bezgam

All Theses

Recently, Michelin has invented an innovative non-pneumatic tire which has potential for improved handling, grip, comfort, and less rolling resistance when compared to a traditional pneumatic tire. The non-pneumatic wheel is manufactured from a molding process with integrated shear ring and collapsible spokes designed to provide optimal uniform ground contact patch with low rolling resistance. The shear band is constructed from a polyurethane material with imbedded inextensible reinforcements. During high speed rolling in initial testing, the original prototype showed high noise levels at frequencies above 100 Hz. A possible source of noise could be due to vibration initiated from the …


Filtering Noise Caused By Sensor Selection For An Ultra-Wide Band Position Tracking System, Danyan Ganjali Dec 2009

Filtering Noise Caused By Sensor Selection For An Ultra-Wide Band Position Tracking System, Danyan Ganjali

All Theses

A filter designed to be optimal for alternating multi-sensor tracking systems is presented. This filter can be used on ultra-wide band position tracking systems such as the Ubisense system. In this thesis, a comprehensive evaluation of the accuracy of the Ubisense tracking system in a multi-room building is given. Then the multi-modality of the noise distribution of such a system is shown. A multi-sensor tracking system is then simulated and a Kalman filter is used to filter the measurements. It is shown that the Kalman filter is not optimal for such a system and the need for a filter that …


Vehicle-Infrastructure Integration (Vii) Enabled Plug-In Hybrid Electric Vehicles (Phevs) For Traffic And Energy Management, Xueying Kang Dec 2009

Vehicle-Infrastructure Integration (Vii) Enabled Plug-In Hybrid Electric Vehicles (Phevs) For Traffic And Energy Management, Xueying Kang

All Theses

Vehicle Infrastructure Integration (VII) program (also known as IntelliDrive) has proven the potential to improve transportation conditions by enabling the communication between vehicles and infrastructure, which provides a wide range of applications in transportation safety and mobility. Plug-in hybrid electric vehicles (PHEVs) that utilize both electrical and gasoline energy are a commercially viable technology with potential to contribute to both sustainable development and environmental conservation through increased fuel economy and reduced emissions. Considering positive potentials of PHEVs and VII in ITS, a framework that integrates PHEVs with VII technology was created in this research utilizing vehicle-to-vehicle and vehicle-to-infrastructure communications for …


Effectiveness Of Team-Building And Teamwork In Real And Virtual Worlds, Rachana Ranade Dec 2009

Effectiveness Of Team-Building And Teamwork In Real And Virtual Worlds, Rachana Ranade

All Theses

Given the increasing importance of globalization and collaboration, this research investigates the possibility of performing team-building training for globally dispersed teams using the capabilities of the virtual world Second Life. Three meeting conditions, the 3D virtual world Second Life, a combination of face-to-face and Second Life and face-to-face were evaluated. Thirty randomly assigned 3 person teams performed an ice-breaker session and then a team-building activity in each meeting condition. Four dependent variables were measured: task completion time; quality of task performance; the subjective satisfaction with the process based on group cohesiveness, perception of the process and satisfaction with the outcome; …


Robust Parameter Design And Finite Element Analysis For A Non-Pneumatic Tire With Low Vibration, Amarnath Proddaturi Dec 2009

Robust Parameter Design And Finite Element Analysis For A Non-Pneumatic Tire With Low Vibration, Amarnath Proddaturi

All Theses

During rolling of a non-pneumatic tire, vibration may be produced by the interaction of collapsible spokes with a shear deformable ring as they enter the contact region, buckle and then snap back into a state of tension. Other potential sources of vibration include the interaction of tire tread with the ground and ring vibration. In the present work, a systematic study of the effects of key geometric design parameters is presented using Taguchi's Robust Parameter Design Method and Orthogonal Arrays.
In the present work, a 2D planar finite element model with geometric non-linearity and explicit time-stepping is used to simulate …


Analysis Of Distributed Denial Of Service Attacks And Countermeasures, Sampada Karandikar Dec 2009

Analysis Of Distributed Denial Of Service Attacks And Countermeasures, Sampada Karandikar

All Theses

Network technology has experienced explosive growth in the past two decades. The vast connectivity of networks all over the world poses monumental risks. The generally accepted philosophy in the security world is that no system or network is completely secure [1] which makes network security a critical concern. The work done in this thesis focuses on Distributed Denial of Service Attacks (DDoS) where legitimate users are prevented from accessing network services. Although a lot of research has been done in this field, these attacks remain one of the most common threats affecting network performance.
One defense against DDoS attacks is …


Monitoring Co Concentration In Fuel Cells Using Microcantilever Sensors, Tugba Demir Dec 2009

Monitoring Co Concentration In Fuel Cells Using Microcantilever Sensors, Tugba Demir

All Theses

Estimating the concentration of gases including carbon monoxide (CO) in the hydrogen fuel exiting the reformer and entering the fuel cell is imperative. A high concentration of CO can cause fuel-cell catalyst poisoning, which permanently destroys the cell. Current practices call for utilizing expensive and bulky spectral analyzers to achieve this task. In addition to their high cost, these methodologies, undoubtedly, hinder the portability and self-containment of the cell. To overcome these problems and achieve the desired objectives of a portable, self-contained, and real-time measurement module, this thesis presents and experimentally investigates a new enabling technology based on utilizing an …


Straight Line Braking Performance Of A Road Vehicle With Non Linear Tire Stiffness Formulation, Anup Khekare Dec 2009

Straight Line Braking Performance Of A Road Vehicle With Non Linear Tire Stiffness Formulation, Anup Khekare

All Theses

The capability of a road vehicle equipped with an Anti-Lock Braking System (ABS) to come to a safe stop depends on factors such as dynamic force between tire and road, surface adhesion coefficient, and the vertical profile of the road. When in panic, a driver's reaction is to step hard on the brakes to make the vehicle stop as soon as possible. Although the use of modern technologies such as ABS and Electronic Stability Control (ESC) have reduced the number of accidents significantly, any further improvement in stopping distance would only complement these technologies.
Michelin has undertaken the development of …


Performance Of Storm Water Stage And Quality Measuring Instruemtnation Of A Small Watershed Using A Remote Monitoring Station, Rebecca Crane Dec 2009

Performance Of Storm Water Stage And Quality Measuring Instruemtnation Of A Small Watershed Using A Remote Monitoring Station, Rebecca Crane

All Theses

ABSTRACT


As economic development proceeds special care must be taken to preserve and sustain our water resources. Monitoring the storm water from a watershed during a rainfall event can help quantify any changes in water quantity and quality. An accurate means of measuring flow is necessary for all watershed monitoring projects. This study was conducted to analyze the performance of stage, turbidity, and temperature measuring devices in a laboratory setting as well as on Honeycutt Creek in Clemson, South Carolina.
The stage measuring devices under study include: a radar level sensor, ultrasonic transmitter, pressure transducer, and a bubbler module. A …


Thermoelastic Behavior Of A Small Bearing Cage, Eric Planting Dec 2009

Thermoelastic Behavior Of A Small Bearing Cage, Eric Planting

All Theses

The full field non contact measurement of objects undergoing testing is one of interest for manufacturers of parts which are graded on their longevity. Unfortunately, for homogenous small parts with irregular geometries, such as bearing cages, the solution for testing is typically to use only a FEA model and compliment the testing of the model with simply cyclically loading the sample until failure. To better understand the stresses and behavior of a small object Thermoelasticity can be employed in order to see in a full field technique what stress patterns exist and their correlation to a FEA model.
The FEA …


Biological Treatment To Remove Color And Toxicity Of Effluent From The Manufacturing Of Navipol Yellow Gr, Larry French Dec 2009

Biological Treatment To Remove Color And Toxicity Of Effluent From The Manufacturing Of Navipol Yellow Gr, Larry French

All Theses

Navipol Yellow GR is an organic solvent azo dye manufactured by Sunbelt Corp. in Rock Hill, SC. The effluent generated from the manufacturing of this dye is highly colored, toxic, and contains trace solvents consisting of mixed xylene isomers and ethyl benzene. Traditional wastewater treatment systems are unable to remove the color and toxicity from the effluent. This study investigated using a sequential anaerobic / aerobic treatment system to decrease color and toxicity of the dye effluent. The anaerobic phase used bacteria cultures of Pseudomonas aeruginosa, Bacillus subtilis, Enterococcus faecalis, or Enterobacter aerogenes to decrease the color of the dye. …


A Genetic Approach To Voltage Collapse Mitigation, Dwarakesh Nallan Chakravartula Dec 2009

A Genetic Approach To Voltage Collapse Mitigation, Dwarakesh Nallan Chakravartula

All Theses

The objective of this thesis is to provide an efficient and accurate corrective solution to a system that is on verge of voltage collapse. This thesis describes, in detail, the development of an optimization scheme that aims to alleviate power system instability and voltage collapse condition based on the principles of an evolutionary approach called Genetic Algorithm. The state of a system is determined using a voltage stability identifier termed Collapse Proximity Index (CPI) and the critical loading condition is identified. Applying principles of Genetic Algorithm, the critical system is brought back to a stable operating region. The sequential procedure …