Engineering Commons^™

Query Expansion Techniques For Enterprise Search, Eric M. Domke

Masters Theses

Although web search remains an active research area, interest in enterprise search has waned. This is despite the fact that the market for enterprise search applications is expected to triple within the next six years, and that knowledge workers spend an average of 1.6 to 2.5 hours each day searching for information. To improve search relevancy, and hence reduce this time, an enterprise- focused application must be able to handle the unique queries and constraints of the enterprise environment. The goal of this thesis research was to develop, implement, and study query expansion techniques that are most effective at improving …

Experimental Study Of Global Luminescent Oil-Film (Glof) Skin-Friction Meter On Delta Wings, Patrick Nicholas Wewengkang

Masters Theses

This thesis describes how the Global Luminescent Oil-Film (GLOF) Skin-Friction Meter can be applied experimentally to extract skin-friction from a set of images. In this study, the effect of oil viscosity, experimental sample size, and step size were considered to see how they would affect the extracted skin-friction using the GLOF method. These results were then compared to published literature on skin-friction diagnostics of delta wings, based on observations of critical characteristics such as reattachment and separation lines. Delta wings of 50°, 55°, 60°, 65°, and 70° sweep angles were built and placed in the Small Wind Tunnel (SWT) at …

Papermaking Factors Affecting Lateral Web Position During Commercial Heat Set Web Offset Printing, George W. Shields

Masters Theses

The interaction of water with paper plays a role in web handling characteristics during commercial heat set web offset printing. Water absorption leads to lower web tension for a given strain.

This research investigates paper properties and their role in preventing lateral web movement from cross machine air flows in the drying section during normal printing operations. Tensile properties of sheets are measured at various moisture contents and then used to determine the equilibrium stress-strain relationship for papers at moisture contents typical of heat set web offset printing. Permeability, fiber orientation and tensile stiffness are evaluated against lateral web movement …

Enhancing Intersection Safety For The Blind And Visually Impaired (Bvi) Pedestrian Using Device-To-Infrastructure Communication, Mohammad Sayyah Al-Akash

Masters Theses

Visually impaired pedestrians have limited mobility options, where they rely heavily on walking and transit for their transportation needs. One of the major issues facing these pedestrians is intersection crossing. Accessible Pedestrian Signals (APS), as a means of helping their intersection crossings, were introduced in the United States as early as 1920 but were not included in the Manual on Uniform Traffic Control Device (MUTCD) until 2000. The most recent type of APS is the beaconing APS which has shown improvements in road crossing abilities of blind pedestrians though it has many downsides to it. This study developed a cane …

Effect Of Arm Motion On Standing Lateral Jump Performance, Arif Ahmed Sohel

Masters Theses

Previous jumping studies have examined the role of arm swing in vertical and horizontal long jump performance, but none have been found which studied the role of arm swing in standing lateral jumps. The purpose of this study was to investigate the effect of arm motion on standing lateral jump performance and to examine the biomechanical mechanisms that may explain differences in jump distance.

A series of lateral jump experiments was performed for two jump cases (free and restricted arms) in which six participants jumped laterally for maximum distance from two in-ground force platforms. A motion capture system collected 3D …

A Cfd Study Of A Multi-Element Front Wing For A Formula One Racing Car, Shardul C. Kachare

Masters Theses

Presently, one of the key factors in determining a success of an open wheel racecar such as Formula One or Indy car, is its aerodynamic efficiency. A modern racecar front wing can generate about 30% of the total downforce. The present study focuses on investigating the aerodynamic characteristics of such highly efficient multi-element front wing for a Formula One racecar by conducting a three-dimensional computational analysis using Reynolds Averaged Navier-Strokes model. A three-dimensional computational study is performed investigating predictive capability of the structured trimmer and unstructured polyhedral meshing model to generate a three-dimensional volume mesh for a multi-element front wing. …

Visualizing The Constructability Of A Steel Structure Using Building Information Modeling And Game Simulation, Mohammed Al Dafaay

Masters Theses

This research aims to visualize a steel structural design to: (1) analyze its constructability, and (2) support collaboration between project participants at the planning stage. The visualization uses Building Information Modeling (BIM) and game engine simulation to develop a realistic interactive simulation for constructability analysis. A case study experiment was conducted on visualizing the erection process of a steel structure to facilitate the understanding of needed construction operation. The simulation incorporated construction domain knowledge through various entity components and predefined interaction rules. Results showed that through such a visualization method, field operation can be observed in real-time at the planning …

Positron Emission Particle Tracking Software Maturation Project, Eric Michael Moore

Masters Theses

Positron Emission Particle Tracking (PEPT) software at the University of Tennessee (MultiPEPT) has demonstrated promising performance in multiple measurement domains. In order to contribute to its further development, a full codebase audit and three focused performance assessments were undertaken. Several improvements were made to the codebase as a result of the audit. The assessments demonstrated a linear axial detector- MultiPEPT response, the effect of mesh size variation, and the effect of temporal overlap variation. A number of best practices are compiled for effective use of MultiPEPT.

Improvements To Nestle: Cross Section Interpolation And N-Group Extension, William Matthews Kirkland

Masters Theses

The NESTLE program is a few-group neutron diffusion reactor core simulator code utilizing the nodal expansion method (NEM). This thesis presents two improvements made to NESTLE regarding cross-section interpolation and multigroup capability.

To quickly and accurately obtain cross sections from lattice physics input data, a new cross section interpolation routine was developed utilizing multidimensional radial basis function interpolation, also known as thin plate spline interpolation. Testing showed that, for existing NESTLE lattice physics input, accuracy was retained but not improved and processing time was longer. However, the new interpolation routine was shown allow much greater exibility in the case matrix …

Developing Leading And Lagging Indicators To Enhance Equipment Reliability In A Lean System, Dhanush Agara Mallesh

Masters Theses

With increasing complexity in equipment, the failure rates are becoming a critical metric due to the unplanned maintenance in a production environment. Unplanned maintenance in manufacturing process is created issues with downtimes and decreasing the reliability of equipment. Failures in equipment have resulted in the loss of revenue to organizations encouraging maintenance practitioners to analyze ways to change unplanned to planned maintenance. Efficient failure prediction models are being developed to learn about the failures in advance. With this information, failures predicted can reduce the downtimes in the system and improve the throughput.

The goal of this thesis is to predict …

Analysis Of Nfirs Data For Sensitivity To Foreclosure And Other Select Features, Alexander Meadows Asbury

Masters Theses

Arson is a grave threat to life and property. In the United States, fire information is collected and disseminated through the National Fire Incident Reporting System (NFIRS). Fire records obtained from NFIRS contain a full range of available information. This information includes the initial incident details in addition to investigative information regarding the cause of ignition and factors contributing to ignition. Combating the arson problem is accomplished in large part by understanding the motives and opportunities of those who commit arson. A common motive for arson is financial gain through insurance fraud. By connecting NFIRS data with mortgage and foreclosure …

Automated Program Profiling And Analysis For Managing Heterogeneous Memory Systems, Adam Palmer Howard

Masters Theses

Many promising memory technologies, such as non-volatile, storage-class memories and high-bandwidth, on-chip RAMs, are beginning to emerge. Since each of these new technologies present tradeoffs distinct from conventional DRAMs, next-generation systems are likely to include multiple tiers of memory storage, each with their own type of devices. To efficiently utilize the available hardware, such systems will need to alter their data management strategies to consider the performance and capabilities provided by each tier.

This work explores a variety of cross-layer strategies for managing application data in heterogeneous memory systems. We propose different program profiling-based techniques to automatically partition program allocation …

Modeling Of Dislocation Channel Formation And Evolution In Irradiated Metals, Peter James Doyle

Masters Theses

Defect-free dislocation channel formation has been reported to promote plastic instability during tensile testing via localized plastic flow, leading to a distinct loss of ductility and strain hardening in many low-temperature irradiated materials. In order to study the underlying mechanisms governing dislocation channel width and formation, the channel formation process is modeled via a simple stochastic dislocation-jog process dependent upon grain size, defect cluster density, and defect size. Dislocations traverse a field of defect clusters and jog stochastically upon defect interaction, forming channels of low defect-density. Based upon prior molecular dynamics (MD) simulations and in-situ experimental transmission electron microscopy (TEM) …

Developing A Platform For Integrating Disability Issues Into City Municipality Decisions; Case Study: City Of Knoxville, Sravanthi Pamu

Masters Theses

The People with Disabilities (PWD) & Senior Citizen (SC) are isolated from the mainstream society, and they face several barriers in everyday life. There is no communication platform for them to express their concerns, in turn, participate in the city municipality policy decisions related to PWD- & SC-friendly city development. The purpose of this research is to integrate disability and senior citizen issues in the city of Knoxville to the city council decisions. The comprehensive literature search is done to identify the frequently mentioned disability and age-friendly city factors. An effective survey was designed to identify the issues in collaboration …

An Analog Cmos Particle Filter, Trevor Watson

Masters Theses

Particle filters are used in a variety of image processing and machine learning applications. Their main use in these applications is to gather information about a system of objects, by using partial or noisy observations collected from sensors. These observations are used to associate points of interest in the observations with objects and maintain this association through a series of observations.

In this paper I will investigate the performance of a particle filter implemented in 130nm analog CMOS hardware. The design goal of the particle filter is low-microwatt power consumption. Using analog hardware, rather than digital ASICs or CPUs I …

Impacts Of The Heterogeneity In Consumer Valuation Of Fuel Economy On Corporate Average Fuel Economy Standards Compliance, Nawei Liu

Masters Theses

This study investigated potential impacts of the heterogeneity in consumer valuation of fuel economy on the compliance with fuel economy standards with two analytical approaches. One approach is to provide theoretical analysis of the heterogeneity impacts on the market acceptance of high-efficiency vehicles. The other approach utilizes a consumer choice based simulation method to analyze the heterogeneity impacts on the compliance with the Corporate Average Fuel Economy (CAFE) Standards for the entire light duty vehicle fleet in the U.S. Our findings suggest two possible conditions which are defined based on relative acceptance of high-efficiency vehicles in the market, and they …

The Development Of Cesium Calcium Bromo-Iodide Scintillator For X-Ray And Gamma Ray Detection, Matthew Starr Loyd

Masters Theses

CsCaI₃:Eu [cesium calcium iodide doped with europium] is a promising scintillator material that can be grown from the melt, but undergoes a tetragonal to orthorhombic phase transition upon cooling at 255 °C [degrees Celsius], causing twinning and cloudiness. The purpose of this work is to suppress this solid to solid phase transition in the CsCaI₃:Eu scintillator, which has a light yield of ~40000 ph/Mev and energy resolution at 662keV of ~4%, by halide replacement to form the compound CsCaBr_xI_3-x:Eu [cesium calcium bromo-iodide doped with europium]. Crystals 8 cm³ [cubic centimeters] in …

Design Considerations For Paralleling Multiple Chips In Sic Power Modules, Fei Yang

Masters Theses

With the benefits of fast switching speed, low on-resistance and high thermal conductivity, silicon carbide (SiC) devices are being implemented in converter designs with high efficiency and high power density. Consequently, SiC power modules are needed. However, some of the preestablished package designs for silicon based power modules are not suitable to manifest the advantages of SiC devices. Therefore, this thesis aims at optimizing the package design to utilize the fast switching capability of SiC devices.

First, the power loop parasitic inductance induced by the package can lead to large voltage spikes with the fast switching SiC device. It can …

Design And Evaluation Of A Sub-1-Volt Read Flash Memory In A Standard 130 Nanometer Cmos Process, David Andrew Basford

Masters Theses

Nonvolatile memory design is a discipline that employs digital and analog circuit design techniques and requires knowledge of semiconductor physics and quantum mechanics. Methods for programming and erasing memory are discussed here, and simulation models are provided for Impact Hot Electron Injection (IHEI), Fowler-Nordheim (FN) tunneling, and direct tunneling. Extensive testing of analog memory cells was used to derive a set of equations that describe the oating-gate characteristics. Measurements of charge retention also revealed several leakage mechanisms, and methods for mitigating leakage are presented.

Fabrication of ash memory in a standard CMOS process presents significant design challenges. The absence of …

Development Of A Multi-Jointed Wing Surface Mover, Collin Arthur Strassburger

Masters Theses

The field of ornithopter research has reached a point where it has become commonplace for Computational Fluid Dynamics (CFD) solvers to have built-in capabilities for rigid solid body motion. This is suitable for micro air vehicles (MAVs) yet is often not exible enough to model wings with dynamic internal structure, such as the wings of birds and bats. There is currently no program available to perform the surface motion of a wing which has multiple independently moving joints. The code, detailed in this paper, provides the user with this type of capability. The bone lengths, joint angle properties, and thickening …

Finite Element Analysis Of Tibiofemoral Contact Mechanics, Erika Fojtik

Masters Theses

The effects of lateral meniscus posterior root avulsions (LMPRA) have been studied in combination with meniscofemoral ligament (MFL) deficiencies. The purpose of this study is to validate a set of biomechanical finite element analyses against previously reported experimental results to predict the contact area and peak contact pressure in the lateral tibiofemoral compartment of the knee during lateral meniscal root avulsions in combination with MFL deficiencies. Patient specific MRI data was used to develop finite element models for three distinct testing conditions: 1) intact, 2) lateral meniscus posterior root avulsion, and 3) lateral meniscus posterior root avulsion with deficient meniscofemoral …

Model Predictive Power Management Of A Hybrid Electric Propulsion System For Aircraft, Tyler J. Wall

Masters Theses

This work presents the switched optimal power flow control for an aircraft with a hybrid electric propulsion system. The propulsion system is a switched system that operates in either of two modes: (i) battery discharging and electric motor propelling and (ii) battery charging and electric motor generating. The aircraft model and components that form the hybrid propulsion system are modeled as either an algebraic power source/sink or as a dynamic model with appropriate power and state interconnections. With the system model defined, a model predictive control power management strategy is set fourth which minimizes a performance index that includes altitude …

Autoplug: An Automated Metadata Service For Smart Outlets, Lurdh Pradeep Reddy Ambati

Masters Theses

Low-cost network-connected smart outlets are now available for monitoring, controlling, and scheduling the energy usage of electrical devices. As a result, such smart outlets are being integrated into automated home management systems, which remotely control them by analyzing and interpreting their data. However, to effectively interpret data and control devices, the system must know the type of device that is plugged into each smart outlet. Existing systems require users to manually input and maintain the outlet metadata that associates a device type with a smart outlet. Such manual operation is time-consuming and error-prone: users must initially inventory all outlet-to-device mappings, …

Analyzing Spark Performance On Spot Instances, Jiannan Tian

Masters Theses

Amazon Spot Instances provide inexpensive service for high-performance computing. With spot instances, it is possible to get at most 90% off as discount in costs by bidding spare Amazon Elastic Computer Cloud (Amazon EC2) instances. In exchange for low cost, spot instances bring the reduced reliability onto the computing environment, because this kind of instance could be revoked abruptly by the providers due to supply and demand, and higher-priority customers are first served.

To achieve high performance on instances with compromised reliability, Spark is applied to run jobs. In this thesis, a wide set of spark experiments are conducted to …

Numerical Simulation Of Multi-Phase Core-Shell Molten Metal Drop Oscillations, Kaushal Sumaria

Masters Theses

The surface tension of liquid metals is an important and scientifically interesting parameter which affects many metallurgical processes such as casting, welding and melt spinning. Conventional methods for measuring surface tension are difficult to use for molten metals above temperatures of 1000 K. Containerless methods are can be used to measure the surface tension of molten metals above 1000 K. Oscillating drop method is one such method where a levitated droplet is allowed to undergo damped oscillations. Using the Rayleigh’s theory for the oscillation of force-free inviscid spherical droplets, surface tension and viscosity of the sample can be calculated from …

Effects Of Malformed Or Absent Valves To Lymphatic Fluid Transport And Lymphedema In Vivo In Mice, Akshay S. Pujari

Masters Theses

Lymph is primarily composed of fluid and proteins from the blood circulatory system that drain into the space surrounding cells, interstitial space. From the interstitial space, the fluid enters and circulates in the lymphatic system until it is delivered into the venous system. In contrast to the blood circulatory system, the lymphatic system lacks a central pumping organ dictating the predominant driving pressure and velocity of lymph. Transport of lymph via capillaries, pre-collecting and collecting lymphatic vessels relies on the synergy between pressure gradients, local tissue motion, valves and lymphatic vessel contractility. The direction of lymph transport is regulated by …

Non-Equispaced Fast Fourier Transforms In Turbulence Simulation, Aditya M. Kulkarni

Masters Theses

Fourier pseudo-spectral method on equispaced grid is one of the approaches in turbulence simulation, to compute derivative of discrete data, using fast Fourier Transform (FFT) and gives low dispersion and dissipation errors. In many turbulent flows the dynamically important scales of motion are concentrated in certain regions which requires a coarser grid for higher accuracy. A coarser grid in other regions minimizes the memory requirement. This requires the use of Non-equispaced Fast Fourier Transform (NFFT) to compute the Fourier transform, by solving a system of linear equations.

To achieve similar accuracy, the NFFT needs to return more Fourier coefficients than …

Energy Efficient Loop Unrolling For Low-Cost Fpgas, Naveen Kumar Dumpala

Masters Theses

Many embedded applications implement block ciphers and sorting and searching algorithms which use multiple loop iterations for computation. These applications often demand low power operation. The power consumption of designs varies with the implementation choices made by designers. The sequential implementation of loop operations consumes minimal area, but latency and clock power are high. Alternatively, loop unrolling causes high glitch power. In this work, we propose a low area overhead approach for unrolling loop iterations that exhibits reduced glitch power. A latch based glitch filter is introduced that reduces the propagation of glitches from one iteration to next. We explore …

Navigation Instruction Validation Tool And Indoor Wayfinding Training System For People With Disabilities, Linlin Ding

Masters Theses

According to World Health Survey, there are 785 million (15.6%) people in the world that live with a disability. It is a well-known fact that lack of access to public transportation is a barrier for people with disabilities in seeking work or accessing health care. In this research, we seek to increase access to public transportation by introducing a virtual pre-travel training system that enables people with disabilities to get familiar with a public transportation venue prior to arriving at the venue. Using this system, users establish a mental map of the target environment prior to their arrival to the …

Evaluation Of Impedance Control On A Powered Hip Exoskeleton, Punith Condoor

Masters Theses

This thesis presents an impedance control strategy for a novel powered hip exoskeleton designed to provide partial assistance and leverage the dynamics of human gait. The control strategy is based on impedance control and provides the user assistance as needed which is determined by the user’s interaction with the exoskeleton. A series elastic element is used to drive the exoskeleton and measures the interaction torque between the user and the device. The device operates in two modes. Free mode is a low impedance state that attempts to provide no assistance. Assist mode increases the gains of the controller to provide …