Engineering Commons^™

Adaptive Transmission For Ofdm, Michael Juang

All Theses

To respond to dynamic channel conditions caused by fading, shadowing, and other time-varying disturbances, orthogonal frequency division multiplexing (OFDM) packet radio systems should adapt transmission parameters on a packet-by-packet basis to maintain or improve performance over the channel. For this to be possible, there are three key ideas that must be addressed: first, how to determine the subchannel conditions; second, which transmission parameters should be adapted; and third, how to adapt those parameters intelligently. In this thesis, we propose a procedure for determining relative subchannel quality without using any traditional channel measurements. Instead, statistics derived solely from subcarrier error counts …

Phonon Transport Analysis Of Semiconductor Nanocomposites Using Monte Carlo Simulations, Mayank Malladi

All Theses

Nanocomposites are composite materials which incorporate nanosized particles, platelets or fibers. The addition of nanosized phases into the bulk matrix can lead to significantly different material properties compared to their macrocomposite counterparts. For nanocomposites, thermal conductivity is one of the most important physical properties. Manipulation and control of thermal conductivity in nanocomposites have impacted a variety of applications. In particular, it has been shown that the phonon thermal conductivity can be reduced significantly in nanocomposites due to the increase in phonon interface scattering while the electrical conductivity can be maintained. This extraordinary property of nanocomposites has been used to enhance …

Speech Enhancement By Exploiting The Baseband Phase Structure Of Voiced Speech For Effective Non-Stationary Noise Estimation, Sanjay Patil

All Theses

Speech enhancement is one of the most important and challenging issues in the speech communication and signal processing field. It aims to minimize the effect of additive noise on the quality and intelligibility of the speech signal. Speech quality is the measure of noise remaining after the processing on the speech signal and of how pleasant the resulting speech sounds, while intelligibility refers to the accuracy of understanding speech. Speech enhancement algorithms are designed to remove the additive noise with minimum speech distortion.The task of speech enhancement is challenging due to lack of knowledge about the corrupting noise. Hence, the …

Mechanistic Characterization Of Rubberized Asphalt Mixture And Design Using Full Scale Tire-Pavement Finite Element Modeling, Sajib Saha

All Theses

Rubberized half-warm mix asphalt (HWMA) is being considered as one of the promising and sustainable solutions to the current environmental and economic crisis of asphalt industry. A fully mechanistic characterization and performance analysis of this mixture subjected to realistic loading and temperature conditions is necessary before its application in a practical pavement structure. The objective of this research is to characterize the viscoelastic properties of rubberized HWMA at different temperatures and to develop and validate a finite element model of a tire-pavement structure. In this research, a generalized Maxwell model is chosen to represent the time dependent stress-strain behavior of …

Development And Testing Of An Impact Plate Yield Monitor For Peanuts, Jacob Fravel

All Theses

Advancements in precision agriculture technologies such as yield monitors have allowed for improved management capabilities and reduced input costs for a number of crops. Most commercialized developments in yield monitoring systems and technologies to date have been directed for use with the major grain crops such as corn, soybeans and cereal grains. This research focuses on development and testing of an impact plate yield monitor system for the peanut harvest. Using a four row peanut combine in virginia type peanuts, 4.8 ha (12 ac) of simultaneous yield data were recorded from an Ag Leader® grain (impact plate) yield monitor and …

A Study Of Gallery Method To Increase Idea Quality In Conceptual Design, Liz Mathew

All Theses

The objective of this research is to evaluate whether gallery method increases idea quality in conceptual design for engineering design problems. The gallery method is a group ideation process which allows individuals to first generate ideas individually, followed by pooling of ideas to conduct group ideation. Design engineers are often encouraged to work in groups to generate concepts and solutions for design problems. However, past research argues that individual ideation results in higher quality design concepts compared to the group ideation methods. The limitations of group ideation such as free riding, production blocking, evaluation apprehension, and goal incongruity are identified …

An Exploratory Study On The Effects Of Goal Alignment, Interventions, And Motivational Factors On Innovative Engineering Design Projects, Blake Linnerud

All Theses

Innovation has become an important facet of engineering design, both in industry and the academy. Many senior-level engineering design courses encourage students to develop innovative solutions to open design projects from industry sponsors. Like industry, these academic problems are tackled by teams of students. Student teams that function at the highest level are more likely to reach the innovative solutions for which they are searching. The research presented in this work focuses on two main areas: (1) understanding what motivates engineers when working on innovative design projects and (2) determining the effects of goal alignment interventions on design teams working …

The Effects Of Different Size Gold Nanoparticles On Mechanical Properties Of Vascular Smooth Muscle Cells Under Mechanical Stretching, Tri Kieu

All Theses

The field of nanotechnology research has seen a large growth in the past few decades due to the great potential of novel nano-size material for useful applications such as drug delivery and medical imaging. Also, they are a promising platform for the detection of terrible diseases such as cancer and atherosclerosis. Although these materials hold great promise, there is very limited understanding about the biological effects of these nanoparticles on normal healthy cells, such as vascular smooth muscle cells (VSMCs). The VSMCs are unique cells due to the two distinct phenotype characteristics it can express: a contractile and a synthetic …

A Probabilistic Analysis Of Islanding Effects In A Modeled Distribution System With Renewable Resources, Paul Gooding

All Theses

For this research, an investigation was undertaken regarding the inclusion of renewable resources into the distribution system. This incorporated the increasing prevalence of solar and wind resources, as well as the development of islanding capabilities within distribution systems.

Rapid Riparian Buffer Width And Quality Analysis Using Lidar In South Carolina, Emre Akturk

All Theses

The importance of protecting water quality and aquatic resources are increasing because of harmful human impacts within and around waterways. Establishing or restoring functional riparian areas protect water quality and are a good mechanism to conserve aquatic systems, plants, and wildlife. Laser-based remote sensing technology offers a high resolution approach to both characterize and document changes in riparian buffer zones (RBZs). The objectives of this study were to build a model to calculate riparian buffer width on both sides of a stream using a LiDAR-derived slope variable, to classify riparian buffers and determine their quality, and to evaluate the appropriateness …

Safety And Operational Characteristics Of Lane Widths On Urban And Rural Roadways A Simulator Study, Meredith Ladue

All Theses

The primary goal for this study was to further evaluate and assess the effect of lane width on the safety and operation of roadways in South Carolina. Due to various site conditions that affect the safety and operations of roadways, highway design engineers often face many challenges when developing appropriate road design standards. To investigate specific site conditions for the South Carolina Department of Transportation (SCDOT) a research study took place. In 2011, Part 1 of this research included field studies conducted by Kevin Baumann and Trey Jordan. Due to the various limitations of the field studies it was evident …

Offshore Wind Energy Study And Its Impact On South Carolina Transmission System, Tingting Wang

All Dissertations

As one of the renewable resources, wind energy is developing dramatically in last ten years. Offshore wind energy, with more stable speed and less environmental impact than onshore wind, will be the direction of large scale wind industry. Large scale wind farm penetration affects power system operation, planning and control. Studies concerning type III turbine based wind farm integration problems such as wind intermittency, harmonics, low voltage ride through capability have made great progress. However, there are few investigations concerning switching transient impacts of large scale type III turbine based offshore wind farm in transmission systems. This topic will gain …

Characteristics And Contributing Factors Of Emergency Vehicle Crashes, Naji Abdelwanis

All Dissertations

The purpose of this study is to determine the contributing factors and characteristics associated with emergency vehicle(EV) crashes in order to generate insights about the emergency crashes. This dissertation consists of three approaches to address the purpose. In the first analysis a binary logistic regression model was used to identify the critical factors associated with EV crashes that resulted in fatality compared to those that did not. In the second analysis, an ordered regression model was used to identify critical factors that contributed to the severity of injuries that EV occupants experience in crashes as well as the effect of …

A Hybrid Method Of Performing Electric Power System Fault Ride-Through Evaluations On Medium Voltage Multi-Megawatt Devices, John Fox

All Dissertations

This dissertation explores the design and analysis of a Hybrid Method of performing electrical power system fault ride-through evaluations on multi-megawatt, medium voltage power conversion equipment. Fault ride-through evaluations on such equipment are needed in order to verify and validate full scale designs prior to being implemented in the field. Ultimately, these evaluations will help in reducing the deployment risks associated with bringing new technologies into the marketplace. This is especially true for renewable energy and utility scale energy storage systems, where a significant amount of attention in recent years has focused on their ever increasing role in power system …

Exploring Multiple Levels Of Performance Modeling For Heterogeneous Systems, Venkittaraman Vivek Pallipuram Krishnamani

All Dissertations

The current trend in High-Performance Computing (HPC) is to extract concurrency from clusters that include heterogeneous resources such as General Purpose Graphical Processing Units (GPGPUs) and Field Programmable Gate Array (FPGAs). Although these heterogeneous systems can provide substantial performance for massively parallel applications, much of the available computing resources are often under-utilized due to inefficient application mapping, load balancing, and tuning. While several performance prediction models exist to efficiently tune applications, they often require significant computing architecture knowledge for reliable prediction. In addition, they do not address multiple levels of design space abstraction and it is often difficult to choose …

Application Of Image Processing And Finite Element Analysis In Modeling Chloride Diffusion In Concrete, Arash Razmjoo

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Utilizing numerical simulation models to predict the long-term mechanical and transport behavior of concrete structures is becoming increasingly popular. The majority of these models have been developed using laboratory test data that consider concrete as a homogeneous material with spherical aggregates. These models could not be a represented of real concrete because it has no primitive shaped aggregate besides that the porosity size and distribution varies from point to point. In this study a novel method for more accurate prediction of the chloride diffusion in concrete was developed. A general framework of the quantitative computed tomography (QCT) and finite element …

Knowledge Extraction From Work Instructions Through Text Processing And Analysis, Abhiram Koneru

All Theses

The objective of this thesis is to design, develop and implement an automated approach to support processing of historical assembly data to extract useful knowledge about assembly instructions and time studies to facilitate the development of decision support systems, for a large automotive original equipment manufacturer (OEM). At a conceptual level, this research establishes a framework for sustainable and scalable approach to extract knowledge from big data using techniques from Natural Language Processing (NLP) and Machine Learning (ML). Process sheets are text documents that contain detailed instructions to assemble a portion of the vehicle, specification of parts and tools to …

Optimal Retrofit Strategy Design For Highway Bridges Under Seismic Hazards: A Case Study Of Charleston, Sc, Shawn Parmelee

All Theses

A significant number of US highway bridges are inadequate for seismic loads and could be seriously damaged or collapse during a relatively small earthquake. On the most recent infrastructure report card from the American Society of Civil Engineers (ASCE), one-third of the bridges in the United States are deemed to be structurally deficient. To improve this situation, at-risk bridges must be identified, evaluated, and effective retrofitting programs implemented to reduce their seismic vulnerabilities. In practice, the Federal Highway Administration uses the expected damage method and indices method to assess the condition of bridges. These methods compare the severity of expected …

Sociallink: A Social Network Based Trust System For P2p File Sharing Systems, Fang Qi

All Theses

In peer-to-peer (P2P) file sharing systems, many autonomous peers without preexisting trust relationships share files with each other. Due to their open environment and distributed structure, these systems are vulnerable to the significant impact from selfish and misbehaving nodes. Free-riding, whitewash, collusion and Sybil attacks are common and serious threats, which severely harm non-malicious users and degrade the system performance. Many trust systems were proposed for P2P file sharing systems to encourage cooperative behaviors and punish non-cooperative behaviors. However, querying reputation values usually generates latency and overhead for every user. To address this problem, a social network based trust system …

Development And Verification Of A Test System To Quantify Strain Of An Optical Displacement Indicator And The Design Of A Strain Indicating Prototype, Josh Lake

All Theses

The organic-rich Middle Devonian Marcellus Shale of the Appalachian basin is a rapidly developing natural gas play. Stratigraphic boundaries of the Marcellus Shale in Westmoreland County, Pennsylvania were identified using geophysical logs from 10 vertical gas-producing wells in a 23 sq. km area. Gamma-ray, bulk density, and resistivity well logs were examined to assess hydrocarbon potential. Values of porosity, total organic carbon (TOC), and water saturation (SW) were derived and mapped by incorporating well-log data into Marcellus-specific formulas. Gamma-ray, penetration (minutes per foot drilled), and mud-logging gas (total gas) from 12 horizontal wells from within the study area were also …

Scratch Damage Evolution On Metals In Total Joint Replacements, Caleb Eljach

All Theses

The goal of total joint replacement (TJR) is to replace nonfunctioning joint components and relieve pain, improve quality of life, and to improve joint function. Although TJR is a successful procedure, more than 54,000 knee revisions occur each year due to factors, such as wear, loosening, infection, fracture, instability, and patient related factors (Ranawat, 2010). TJRs consist of components typically composed of polyethylene and a metallic counterface (Navarro, 2008). The sliding contact that occurs between the metal and polyethylene components has been well studied and is shown to produce both surface damage and wear of the implant components (Barbour, 1997; …

Improvements In The Process Of Biohydrogen Production By Thermotoga Neapolitana, Louis Hill

All Theses

The production of biological hydrogen is an important process for the future of sustainability and alternative energies. Thermotoga neapolitana is a hyperthermophilic bacterium that produces H ₂ , CO₂ and acetate via fermentation. The goal of the research was to investigate the sustainable production of H₂ gas using waste agricultural feedstocks, recycled water and a simplified N₂ sparging method technique. A limited sparging method was developed which includes 1 minute of N₂ gas sparging of the reactor headspace and 90 minutes of idle reaction time for cysteine-HCl to react with dissolved oxygen prior to inoculation. This …

Interstitial Cell Seeding And Dynamic Conditioning Of Aortic Heart Valve Scaffolds, Allison Kennamer

All Theses

In 2011, U.S. Markets for Heart Valve Repair and Replacement Products estimated that roughly four million people in the United States are diagnosed with a heart valve disorder annually. And in the following year, the American Heart Association reported that approximately 35,000 deaths in the US were either directly or indirectly attributed to heart valve disease. Diseases of the heart valve are degenerative in nature and therefore progressively worsen unbeknownst to the patient until symptoms become clinically relevant. By this time, the valve is in such poor condition that complete replacement is often the only effective treatment. Current solutions are …

Evaluating The Predictive Capability Of Numerical Models Considering Robustness To Non-Probabilistic Uncertianty In The Input Parameters, Parker Shields

All Theses

The paradigm of model evaluation is challenged by compensations between various forms of errors and uncertainties that are inherent to the model development process due to, for instance, imprecise model input parameters, scarcity of experimental data and lack of knowledge regarding an accurate mathematical representation of the system. When calibrating model input parameters based on fidelity to experiments, such compensations lead to non-unique solutions. In turn, the existence of non-unique solutions makes the selection and use of one `best' numerical model risky. Therefore, it becomes necessary to evaluate model performance based not only on the fidelity of the predictions to …

Functional Stroke Recovery Through Tissue Engineered Niche Neural Constructs, Natasha Topoluk

All Theses

According to the Centers for Disease Control and Prevention, stroke is statistically responsible for 1 in every 19 deaths of American citizens.5 Stroke is the leading cause of permanent disability due to the fact that it compromises both cellular and tissue components of the brain, leading to the formation of a physical void within the tissue. Current research approaches address the cellular component by injecting stem cells into this void; however, extremely low cell engraftment, high injected cell death, and overall no matrix regeneration are observed. Additionally, these stem cells do not remain committed to a neural lineage. We propose …

Analyzing Requirement Type Influence On Generated Solutions, Emily Worinkeng

All Theses

Several ideation methods are available and used by engineering designers to enable the generation of alternative designs [1]. However, there has been little work done to understand the role that the design problem given to participants plays in the ideation process. The contribution of this research is found through the proposed guidelines with respect to the type of requirements to include as part of the design problem in order to achieve the desired quantity, quality, novelty, and variety of solutions during the early stages of the design process. This work is the first attempt at analyzing the effect of requirement …

Bite Detection And Differentiation Using Templates Of Wrist Motion, Soheila Eskandari

All Theses

We introduce a new algorithm of bite detection during an eating activity based on template matching. The algorithm uses a template to model the motion of the wrist over a 6-second window centered on the time when a person takes a bite. We also determine if different types of bites (for example food vs. drink, or using different types of utensils) have different wrist motion templates. This method is implemented on 22,383 bites and 5 different types of templates are built. We then describe a method to recognize different types of bites using the set of templates. The obtained accuracy …

Evaporation And Modeling Water Availability In The Savannah River Basin, Ryne Phillips

All Theses

Four methods for estimating lake evaporation are presented and compared. Three are mass transfer methods that incorporated high resolution satellite imagery obtained from the MODIS sensor on the Terra and Aqua satellites. The fourth is the traditional pan method, which used monthly derived pan coefficients and pan evaporation measurements from a Class A evaporation pan located in Clemson, SC.

The four evaporation methods were used to estimate lake evaporation from the five major lakes in the Savannah River Basin for a period of more than one decade. Analysis of the evaporation rates clearly illustrated the uncertainty in daily, monthly, and …

Chemical, Physical, And Moisture Release Characteristics Of Compost Based Potting Media, Tianzhen Wang

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A commercially available composted cow manure was used as a potting media amendment. A common base mix for woody ornamentals of 8 parts pine bark and 1 part sand was compared with 3 other mixes that contained 20%, 30%, and 40% compost (v/v). The remaining fraction of these three mixes was the base mix (bark and sand). Samples of the pine bark and compost were analyzed to determine the following plant nutrients and mineral concentrations: nitrogen (organic and soluble), carbon, P2O5, K2O, Ca, S, Mg, Mn, Cu, Zn, Na, Fe, and Al.

Assessing Potential Environmental Impacts According To Probable Patterns Of Switchgrass Adoption In The Southeastern Us, Benjamin Sharp

All Dissertations

To assess the overall net impact of an emerging technology, life cycle assessment (LCA) must be accompanied by projections of adoption. Diffusion of innovation research provides tools that incorporate economic and social variables to explain and forecast integration of technologies. A switchgrass-to-ethanol case study for the southeastern U.S. is used to demonstrate methods for gauging aggregate environmental effects of an emerging energy technology. Before applying diffusion concepts, breakeven capacities are calculated for land in row crops, hay, pasture and marginal land. Breakeven curves are generated to provide upper bounds to switchgrass adoption over a range of farm-gate prices. The amount …