Engineering Commons^™

Phasor Measurement Unit Deployment Approach For Maximum Observability Considering Vulnerability Analysis, Jyoti Paudel

All Theses

In recent years, there has been growing interest of synchrophasor measurements like Phasor Measurement Units (PMUs) Power systems are now being gradually populated by PMU since they provide significant phasor information for the protection and control of power systems during normal and abnormal situations. There are several applications of PMUs, out of which state estimation is a widely used. To improve the robustness of state estimation, different approaches for placement of PMUs have been studied. This thesis introduces an approach for deployment the PMUs considering its vulnerability. Two different analysis have been considered to solve the problem of locating PMUs …

A Novel Approach To Evaluating Compact Finite Differences And Similar Tridiagonal Schemes On Gpu-Accelerated Clusters, Ashwin Trikuta Srinath

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Compact finite difference schemes are widely used in the direct numerical simulation of fluid flows for their ability to better resolve the small scales of turbulence. However, they can be expensive to evaluate and difficult to parallelize. In this work, we present an approach for the computation of compact finite differences and similar tridiagonal schemes on graphics processing units (GPUs). We present a variant of the cyclic reduction algorithm for solving the tridiagonal linear systems that arise in such numerical schemes. We study the impact of the matrix structure on the cyclic reduction algorithm and show that precomputing forward reduction …

Characterization Of A Multi-Laminate Angle-Ply Af Patch For Annulus Fibrosus Repair, Ryan Borem

All Theses

Annually, over 5.7 million Americans are diagnosed with two IVD-associated pathologies: IVD herniation (IVDH- a mechanical disruption of the concentric fibrous layers of the annulus fibrosus (AF))) and degeneration (IVDD- a multifactorial process which initiates within the inner gelatinous core (NP), and results in a biochemical degradation of NP tissue), with over 2.7 million requiring surgical inteventions.1,2 Although both underlying pathologies are different, quite often they both lead to a decrease in IVD height, impaired mechanical function, and increased pain and disability. These pain symptoms affect approximately 80% of the adult population during their lifetime with estimated expenditures exceeding $85.9 …

Analysis Of Citrate Content In Bone Using High Performance Liquid Chromatography, Matthew Konstantin Pysh

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Approximately 1.5 wt. % of bone is comprised of citrate molecules bound to the surface of apatite crystals. Furthermore, 80 to 90% of physiological citrate is contained within bone. Recently, interest in citrate has increased due to the potential of a citrate based method for estimation of postmortem intervals, time since death, of skeletal remains. The broad objective of this research was to develop and validate a High-Performance Liquid Chromatography (HPLC) method for quantitative and qualitative analysis of citrate in bone. An appropriate HPLC column and operating conditions for the detection of citrate were selected and subsequently used to analyze …

Understanding The Automotive Pedal Usage And Foot Movement Characteristics Of Older Drivers, Yubin Xi

All Dissertations

The purpose of this study was to understand the pedal usage characteristics of older drivers in various driving tasks using an instrumented vehicle. This study stemmed from the prevalence of the pedal application errors (PAEs) and the older drivers’overrepresentation in crashes caused by PAEs.

With the population increasing and becoming older, it is estimated that in 2020 there will be 40 million drivers over the age of 65 in the United States. Compared with their younger counterparts, older drivers are facing declining cognitive and physical abilities, such as impaired vision, slower reaction time and diminishing range of limb motion. Because …

A Training Assistant Tool For The Automated Visual Inspection System, Mohan Karthik Ramaraj

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This thesis considers the problem of assisting a human user setting up an automated Visual Inspection (VI) system. The VI system uses a stationary camera on an automobile assembly line to inspect cars as they pass by. The inspection process is intended to identify when parts have been missed or incorrect parts have been assembled. The result is reported to a human working on the assembly line who then can take corrective actions. As originally developed, the system requires a setup phase in which the human user places the camera and records a video of at least 30 minutes length …

Designing Optical Properties In Infrared Glass, Benn Gleason

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Chalcogenide glasses (ChGs) are well-known for their attractive optical properties, such as high refractive index and transparency in across infrared wavelengths. ChGs also possess the ability to compositionally tune properties such as the refractive index, the thermo-optic coefficient, and other non-optical properties. Chalcogenide glasses with compositionally tailored physical and optical properties will provide optical designers with new materials necessary to create novel infrared imaging systems requiring new or expanded functionality. This dissertation has evaluated the relationship between glass composition, the resulting atomic structure, and resulting optical and thermo-optical properties, with specific focus on the infrared refractive index and the thermo-optic …

Investigation Into Mechanisms And Mitigation Of Alkali-Silica Reaction In Sustainable Portland Cement Concrete Containing Recycled Glass Materials, Kaveh Afshinnia

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A significant portion of recycled glass from municipal waste streams is not found to be suitable for reuse as cullet in the production of new glass containers, and as a result it is disposed in landfills. One of the appropriate ways to reduce the disposal of waste glass in landfills is by using it in portland cement concrete as an aggregate material and/or supplementary cementitious material to replace portion of portland cement. The high silica content of the soda glass (approximately 70%) can potentially behave as a pozzolanic material when finely ground, which may enhance the mechanical and durability properties …

Operational Analysis Of Traditional Access Management Strategies & Demand-Responsive Access Control On Arterials, Joshua Mitchell

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Arterials are typically characterized by closely-spaced signalized intersections, high driveway density, and high traffic volumes. These characteristics contribute to congestion, as well as crashes. Access management strategies can address both operational and safety issues on urban arterials. This research focuses on the operational impacts of access management with two objectives: (1) quantify the impacts of ‘traditional’ access management strategies and (2) quantify the impacts of demand-responsive access control. To satisfy Objective 1, four traditional access management strategies were tested – (i) access spacing, (ii) corner clearance, (iii) access restriction, and (iv) raised median implementation. These were analyzed in four respective …

Analysis And Synthesis Of Effective Human-Robot Interaction At Varying Levels In Control Hierarchy, David Spencer

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Robot controller design is usually hierarchical with both high-level task and motion planning and low-level control law design. In the presented works, we investigate methods for low-level and high-level control designs to guarantee joint performance of human-robot interaction (HRI). In the first work, a low-level method using the switched linear quadratic regulator (SLQR), an optimal control policy based on a quadratic cost function, is used. By incorporating measures of robot performance and human workload, it can be determined when to utilize the human operator in a method that improves overall task performance while reducing operator workload. This method is demonstrated …

Design And Analysis Of Foundation For Onshore Tall Wind Turbines, Shweta Shrestha

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Wind turbines play a vital role in producing sustainable and clean energy to fulfill the growing energy needs. Energy generated from wind turbines being more sustainable and cost effective, many countries have taken a major step to develop wind turbines with large capacity. There has been a significant reduction in the levelized cost of energy (LCOE) since the 1980’s from the development of larger wind farms and from consistent performance improvements of wind turbine components. The power generation capacity of wind turbines has increased significantly over the years with the use of taller towers. When the tower height increases, the …

Detection And Recovery From Camera Bump During Automated Inspection Of Automobiles On An Assembly Line, Shawn Mathew

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This thesis details the steps taken to detect and compensate for camera bumps while per- forming part identification using VI at the BMW manufacturing plant and on the simulation testbed. For the system presented here to work, the user is required to record a video from the camera before the camera is bumped and one after the camera has been bumped. The premise behind the method suggested here is that the transformation between the background in the pre- and post-bump video will be equal to the transformation in the foreground. A Background extraction program is used to generate a background …

Condition Assessment Of Clemson University's Parking Network And Development Of A Framework To Support Pavement Management, Yazurved Sai Vishwaksen Aravalli

All Theses

The concept of pavement management system for Clemson University parking network provides a rehabilitation programming strategy for parking and transportation services department at Clemson University. The department invests funds to keep parking lots in good condition which pays large rewards in terms of savings for both Clemson University and parking lot users. Clemson University Pavement Management System (CU-PMS) will provide quality information for better decisions to ensure the funds invested gets the best value. This project consists of developing a useful and efficient network-level PMS for Clemson University parking lot network. The study area includes all the parking lots in …

The Performance Of Quaternary Amplitude Modulation With Quaternary Spreading In The Presence Of Interfering Signals, Allison Manhard

All Theses

Multiple-access digital communications is considered with direct-sequence spread-spectrum (DS-SS) quadrature amplitude modulation and quaternary spreading in each transmission. Each transmitted signal undergoes attenuation and a delay at a receiver in the additive white Gaussian noise channel. The receiver uses coherent demodulation with a correlation detector synchronized to the one of the K received signals so that the K - 1 other transmissions act as interference. The average probability of error at the output of the detector is determined using Monte Carlo simulation and compared with an approximation in which the interference component in each detection statistic is approximated by a …

Control Of Thermoforming Process Parameters To Manufacture Surfaces With Pin-Based Tooling, Vijay Sarthy Mysore Sreedhara

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Many manufacturing processes used to mass produce parts rely on expensive and time consuming tooling. These processes include sheet metal forming, injection molding, casting, and thermoforming. The time invested in design and development of tooling can be justified for high-production volumes. However, for low-volume production and customized products, the tooling investment cannot be amortized. Flexible tooling has been developed to address the needs of smaller production volumes. Reconfigurable pin tooling is an example of flexible tooling that relies on a matrix of adjustable-height pins to produce approximate surfaces. A key challenge in pin-based tooling is achieving accurate high quality surfaces …

Detecting Occlusions Of Automobile Parts Being Inspected By A Camera System During Manufacturing Assembly, Jayadevan Puthumanappilly

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This thesis considers the problem of detecting occlusions in automobile parts on a moving assembly line in an automotive manufacturing plant. This work builds on the existing ``Visual Inspector'' (VI) system developed as a joint research project between Clemson University and the BMW Spartanburg manufacturing plant. The goal is to develop a method that can successfully detect occlusions in real-time. VI is a detector and classifier system that uses video cameras to determine the correct installation of a part in the assembly line. In the current version of VI, an occluded part is flagged simply as `not OK' - as …

Structural Optimization Using Parametric Programming Method, Krupakaran Ravichandraan

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The Parametric Programming method is investigated to consider its applicability to structural optimization problems. It is used to solve optimization problems that have design variables as implicit functions of some independent input parameter(s). It provides optimal solutions as a parametric function of the input parameter(s) for the entire parameter space of interest. It does not require the detailed discrete optimizations needed at a large number of parameter values as in traditional non-parametric optimization. Parametric programming is widely used in optimal controls, model predictive control, scheduling, process synthesis and material design under uncertainty due to the above mentioned benefits. Its benefits …

Single Particle And Biological Cell Detection By A Radio Frequency Interferometer, Zheng Wang

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This thesis presents a series of studies on single particle and biological cell detection and differentiation by a radio frequency (RF) interferometer system. Several techniques, such as dielectrophoresis (DEP), time domain method and 3D focusing have been illustrated and investigated to demonstrate the capacity of interrogating the electric property of single particle or biological cell by the RF interferometer. Silica particles and live yeast cells are trapped at the sensing area by DEP force and detected by the RF sensor. Solutions of particle mixtures (~4 μm silica and ~10 μm polystyrene) and cell mixtures (viable and non-viable yeast cells, normal …

Design Of A Web Application To Improve The Efficiency Of Crnas., Venkatramanan Chanchapalli Madhavan

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Physical artifacts such as whiteboards have been successfully used in healthcare facilities to keep track of dynamic changes in information and to manage work schedules. Since these whiteboards are easy- to- use and do not require any technical expertise, they have been easy- to-adopt. Additionally, they act as memory aids for the users by capturing transient information. However, they have their own limitations, the primary ones being the lack of mobility and real-time updates, both of which are crucial in a high consequence environment such as a healthcare facility. These whiteboards are usually kept in a central location with the …

Practical Robust Geotechnical Design- Methodology And Applications, Sara Khoshnevisan

All Dissertations

This dissertation advances the robust geotechnical design methodology by offering improvements, which makes it more efficient and practical for the design of geotechnical systems. Robust geotechnical design (RGD) methodology seeks an optimal design, which is insensitive to, or robust against, the variation in the uncertain input parameters (called “noise factors”) by only adjusting the easy to control parameters (called “design parameters”). The main goal of robust design is to consider safety, cost and robustness simultaneously. Because the cost and the robustness are conflicting objectives, the multi-objective optimization that considers these two objectives while enforcing the safety constraint yields not a …

In Vitro Multi-Scale Patient-Specific Modeling Of Hemodynamics In Stage 1 Norwood Palliation For The Treatment Of Single Ventricle Heart Disease, Tianqi Hang

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Hypoplastic left heart syndrome (HLHS) is a congenital heart defect in which the left ventricle is severely underdeveloped. The Norwood procedure is the first stage procedure to make an unrestrictive systemic blood flow and at the same time balance it with the pulmonary flow. This is done by constructing a neo-aorta using the pulmonary artery root and the autologous aorta, and then installing a shunt to the pulmonary artery. Variations of the Norwood surgery include the modified Blalock-Taussig (mBT) shunt, which diverts blood from the innominate artery to the pulmonary artery (PA), and the Right Ventricle Shunt (RVS), which diverts …

Nursing Interruption Dynamics: The Impact Of Work System Factors, Yushi Yang

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Interruptions occur frequently in healthcare work systems. Hands-free Communication Devices (HCDs) were implemented in healthcare work systems to support the interruption process. However, from a sociotechnical systems perspective, HCDs may introduce new complications and unintended consequences to the work system. Research gaps exist in investigating the complexity of HCD interruptions in the real-world context. This dissertation aims to understand HCD interruption dynamics in the nursing work systems, using qualitative research methods. The first study examined the major differences between face-to-face and HCD-mediated interruptions, based on 30 hours of field observations in the acute care setting. Three major differences included: (1) …

Electromechanical Modeling Of A Honeycomb Core Integrated Vibration Energy Converter With Increased Specific Power For Energy Harvesting Applications, Nataraj Chandrasekharan

All Dissertations

Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters …

An Investigation Of The Efficiency Of Synergistic Multicultural Teams, Melissa Dorlette Paul

All Dissertations

The current globalized environment has increased the prevalence of multicultural teams in the workplace. While much research has focused on the advantages of such teams, the challenges companies should anticipate when using them has not received as much attention. These difficulties, specifically communication and trust, need to be considered to ensure that the company remains competitive in an economy driven by growing client expectations. In addition, companies often have to meet tight delivery schedules in order to survive, an expectation which adds strain on production teams. Efforts to address these issues have ranged widely, with some researchers suggesting cultural awareness …

Robust Model Development For Evaluation Of Existing Structures, Saurabh Prabhu

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In the context of scientific computing, validation aims to determine the worthiness of a model in supporting critical decision making. This determination must occur given the imperfections in the mathematical representation resulting from the unavoidable idealizations of physics phenomena. Uncertainty in parameter values furthers the validation problems due to the inevitable lack of information about material properties, boundary conditions, loads, etc. which must be taken into account in making predictions about structural response. The determination of worthiness then becomes assessing whether an unavoidably imperfect mathematical model, subjected to poorly known input parameters, can predict sufficiently well in its intended purpose. …

Electrospray Deposition Of Chalcogenide Glass Films For Gradient Refractive Index And Quantum Dot Incorporation, Spencer Novak

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Chalcogenide glasses (ChGs) are well-known for their optical properties, making them ideal candidates for emerging applications of mid-infrared microphotonic devices, such as lab-on-a-chip chemical sensing devices, which currently demand additional flexibility in processing and materials available to realize new device designs. Solution-derived processing of ChG films, initially developed in the 1980s by Chern and Lauks, has consisted mainly of spin-coating and offers unique advantages over the more traditional physical vapor deposition techniques. In the present effort, the nanoparticles of interest are luminescent quantum dots (QDs), which can be used as an on-chip source of light for a planar chemical sensing …

Proportioning And Properties Of Ultra-High Performance Concrete Mixtures For Application In Shear Keys Of Precast Concrete Bridges, Zhengqi Li

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Ultra-high performance concrete (UHPC) is defined as a cementitious based composite material with compressive strengths above 150 MPa, pre-and post-cracking tensile strengths above 5 MPa, and enhanced durability. To achieve desired properties, UHPC is typically produced with low water-cementitious materials (w/cm) ratio (i.e. w/cm < 0.25), high cementitious materials content (i.e. >1000 kg/m3), high quality aggregate, high dosage of high-range water reducing admixture (HRWRA) and reinforcing fibers. UHPC has distinct advantages in applications where narrow formwork and dense reinforcement are inevitable, high compressive strength concrete material is required and the surrounding environment is aggressive. The construction of shear keys in precast bridges is one of the important …

Developing Effective Ground And Space-Based Soil Moisture Sensing Techniques For Irrigating Cotton In Coastal Plain Soils, Xin Qiao

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Irrigation scheduling based on soil moisture sensor readings has gained popularity in the past few decades since it can enhance crop yield while saving water. Such method is limited since the representativeness of an individual soil moisture sensor measurement is questionable in a large field with variable soil type and texture. The optimum location of soil moisture sensors needs to be determined within such a production field for effective sensor-based irrigation scheduling. Therefore, the first object of this study was to investigate the optimum sensor location and the number of moisture sensors required for irrigating cotton in coastal plain soils. …

Optimization Of Pyrochlore Catalysts For The Dry Reforming Of Methane, Felipe Polo Garzon

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The conversion of methane into syngas (a mixture of CO and H2), which can be further converted into a variety of chemicals and particularly liquid fuels, is of growing importance given recent increases in methane production world-wide. Furthermore, since using CO2 as the co-feed offers many environmental advantages, dry reforming of methane (DRM, CH4 + CO2 ⇌ 2CO + 2H2) has received renewed attention. In recent years, experimentalists have shown that the Rh-substituted lanthanum zirconate pyrochlore (LRhZ) material is catalytically active for DRM, exhibits long-term thermal stability and resists deactivation; however, previous to this doctoral work, a detailed understanding of …

Design And Synthesis Of Polymer, Carbon And Composite Electrodes For High Energy And High Power Supercapacitors, Margarita Arcila-Velez

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Supercapacitors (SCs) are promising energy storage devices because they deliver energy faster than Li-ion batteries and store larger amounts of charge compared to dielectric capacitors. SCs are classified in electrical double layer capacitors (EDLCs) and pseudocapacitors, based on their charge storage mechanism. EDLCs store charge electrostatically, i.e. by physical charge separation. This mechanism limits the storable amount of energy to the available surface area of the electrode, typically made of carbon materials, but grants good cycling stability of the SC device. Pseudocapacitor electrodes, commonly made of conducting polymers or metal oxides, store charge faradaically, i.e. through redox reactions throughout the …