Digital Commons Network^™

Measuring Digital System Latency From Sensing To Actuation At Continuous 1 Millisecond Resolution, Weixin Wu

All Theses

This thesis describes a new method for measuring the end-to-end latency between sensing and actuation in a digital computing system. Compared to previous work, which generally measures the latency at 16-33 ms intervals or at discrete events separated by hundreds of ms, our new method measures the latency continuously at 1 millisecond resolution. This allows for the observation of variations in latency over sub 1 s periods, instead of relying upon averages of measurements. We have applied our method to two systems, the ?rst using a camera for sensing and an LCD monitor for actuation, and the second using an …

Printing Carbon Nanotube Based Supercapacitors For Packaging, Alexandra Hartman

All Theses

Living in a world full of portable electronics, there is great need for energy storage devices. Currently, limitations for storage involve power inefficiencies as well as bulkiness. This is why printable charge storage devices that display good electrochemical performance are needed. It is for this reason that research into the production and packaging of carbon nanotube based super capacitors was carried out.
A super capacitor can be built by using high surface area multi-walled carbon nanotubes suspended in an ionic liquid. The two active electrodes are made from a combination of the multi-walled carbon nanotubes and an ionic liquid, ground …

The Accuracy Of Drivers' Perceptions Of The Effects Of Headlight Glare On Their Ability To Recognize Pedestrians At Night, Stephanie Whetsel

All Theses

Recently, researchers have begun to assess the extent to which drivers believe their ability to see is degraded by headlight glare. Research has suggested that drivers may overestimate the extent to which glare from headlamps degrades their ability to see letters. This project extended this research by quantifying the accuracy with which drivers judge that glare interferes with their ability to see pedestrians at night. On average, participants overestimated the distance at which drivers would see a pedestrian by a factor of more than three. Headlight glare disrupted participants' ability to recognize the pedestrian wearing both non-retroreflective and reflective clothing …

'The Purpose Of Poetry Is To Seem As Lifelike As Possible ...': Communicating The Alive Through Contemporary Poet Chelsey Minnis's Supplemental Language, Lindsay Niedringhaus

All Theses

Contemporary poet Chelsey Minnis has a style that is unlike any other poet of today. Throughout all three of Minnis‘s collections, the speaker is unpredictable in her tone, content, and approach, appearing quite random and flippant. Furthermore, Minnis‘s distinctive use of ellipses and ideograms also separate her poetry from any of that of her contemporaries, as they take such a prominent role within her poems, refusing to be ignored. When first reading a Minnis poem, many do not know how to even begin to analyze it, as the poetry does not adhere to any traditional codes, and no rules exist …

Empirical Study: Failure Of Glass-To-Metal Seals During Shock Loading, William Horton

All Theses

The goal of this thesis was to determine the empirical failure mechanisms and sequence of cartridge actuated devices (CADs) experiencing failure of the glass-to-metal (G/M) seal. Impact loading was conducted with a drop weight machine at room temperature and 300¡F, and then empirically analyzed with high speed video. Resulting peak overload force, shear stress, and impulse were all calculated. The room temperature samples were found to absorb twice the impulse upon failure as the elevated temperature G/M seals. Closed-form and three-dimensional finite element analysis was used to determine the stress state and deformation upon loading. Furthermore, high speed data was …

The Design Of A Haptic Device For Training And Evaluating Surgeon And Novice Laparoscopic Movement Skills, Ryan Bontreger

All Theses

As proper levels of force application are necessary to ensure patient safety, and training hours with an expert on live subjects are difficult, enhanced computer-based training is needed to teach the next generation of surgeons. Considering the role of touch in surgery, there is a need for a device capable of discerning the haptic ability of surgical trainees. This need is amplified by minimally invasive surgical techniques where a surgeon's sense of tissue properties comes not directly through their own hands but indirectly through the tools. A haptic device capable of producing a realistic range of forces and motions that …

Analysis And Parameterization Of The Flight Of Ember Generation Experiments, Hillary Harris

All Theses

This thesis presents a study on ember flight modeling based on a series of wind tunnel experiments. The purpose of these experiments and the data collected was to provide the input conditions for an ember flight model in order to compare and validate the model predictions. An analysis was performed which determined the sensitivity of model predictions of downwind mass distribution to uncertainties in the model input parameters.
From the wind tunnel experiments, flight distances were measured and characteristic ember size distributions were obtained from the collected data. A flight model was developed based on standard models published in the …

Do The Ethics Of Authorship Matter?: Exploring The Implications Of The Office Of Research Integrity's Narrow Definition Of Research Misconduct, Caroline Linvill

All Theses

Over the past 25 years, federal government entities have become involved in defining and regulating misconduct in scientific research. Consistently, these definitions of research misconduct forbid three key actions--falsification, fabrication, and plagiarism--but do not take into account other professional communication issues, mainly authorship. This lack of acknowledgement and regulation of authorship--particularly from the Office of Research Integrity, the nation's highest research ethics body--seems to imply and communicate that the ethics of authorship are not important in science. However, this thesis demonstrates, through rhetorical, historical and interview research, that authorship ethics do matter to scientists; in fact, authorship is a leading …

An Extension Of Social Facilitation Theory To The Decision-Making Domain, Allison Wallace

All Theses

Social facilitation has traditionally been defined as the influence of the presence of others on an individual's task performance. Social presence has been shown to either facilitate or impair performance based on various moderating variables, including the more recent investigation of individual differences, but researchers have yet to extend social facilitation theory to the domain of decision-making. This study evaluates the effect of social presence on individual decision-making, using the personality traits of extraversion, neuroticism, self-esteem, social anxiety, and trait anxiety as potential moderating variables of this effect. We found that affiliative individuals, marked by high extraversion and high self-esteem, …

The Performance Of Serial, Matched-Filter Packet Acquisition Using Transmit And Receive Antenna Diversity, Shivram Ramanathan

All Theses

The performance of serial, matched-filter acquisition is evaluated for asynchronous packet radio communications using transmit or receive antenna diversity. Transmit diversity is achieved using dual antenna transmissions of orthogonal preamble sequences and receive diversity is achieved using dual antenna reception of a single preamble sequence. Sequential test statistics are formed using non-coherent combining of the outputs from the orthogonal preamble matched-filters if transmitter diversity is used; the test statistics are formed using non coherent combining of the outputs from the preamble matched-filter in each receiver chain if receiver diversity is used. Threshold-based acquisition of the test statistics using both fixed …

The Anglo-American Press And The 'Secret' Rearmament Of Hitler's Germany, 1933 To 1935, Jason Ranke

All Theses

This thesis will examine the Anglo-American press coverage of Germany's secret rearmament between 1933 and 1935, with the aim of pursuing three main objectives:
1. Describe the rearmament process occurring in Germany and how it related to, or influenced, the country's position in international affairs.
2. Investigate the accuracy and objectivity of Anglo-American press coverage of the German rearmament. This goal will be achieved by analyzing and comparing information from several major American and British newspapers and magazines from 1933 to 1935 with data gleaned from the principal secondary sources on Nazi rearmament and foreign policy.
3. Determine how Hitler …

Data-Intensive Computing For Bioinformatics Using Virtualization Technologies And Hpc Infrastructures, Pengfei Xuan

All Theses

The bioinformatics applications often involve many computational components and massive data sets, which are very difficult to be deployed on a single computing machine. In this thesis, we designed a data-intensive computing platform for bioinformatics applications using virtualization technologies and high performance computing (HPC) infrastructures with the concept of multi-tier architecture, which can seamlessly integrate the web user interface (presentation tier), scientific workflow (logic tier) and computing infrastructure (data/computing tier). We demonstrated our platform on two bioinformatics projects. First, we redesigned and deployed the cotton marker database (CMD) (http://www.cottonmarker.org), a centralized web portal in the cotton research community, using the …

Fault-Tree Model For Bridge Collapse Risk Analysis, Caitlyn Davis-Mcdaniel

All Theses

Bridges are vital components of the United States surface transportation infrastructure and, moreover, support the growth of our nation's economy. However, over the past few decades the design capacity and service condition of many bridges in the U.S. has been challenged. Numerous incidents of bridge collapse call for an urgent need to develop a systematic method of assessing the failure risks and identifying the initiating events that can lead to a bridge collapse. This thesis presents a process of bridge failure risk analysis through fault-tree modeling and identification of specific countermeasures, to minimize failure risk, related to structural health monitoring …

Development And Application Of A Three-Dimensional Probabilistic Wind-Borne Debris Trajectory Model, James Grayson

All Theses

This research presents a probabilistic debris trajectory model adapted from current 6-degree-of-freedom (6-DoF) deterministic models, in which the aleatoric (inherent) uncertainty is explicitly considered in the proposed probabilistic model. While the inherent randomness in the debris flight trajectory is irreducible due to the wind turbulence, variation in wind direction, gustiness of the wind event and so forth, the proposed probabilistic model seeks to address these uncertainties through Monte Carlo simulations with the appropriate statistical distributions applied to the governing equations of motion of the debris. Verification of the probabilistic debris trajectory model is performed through an analytical and visual comparison …

Evaluating The Usability Of System-Generated And User-Generated Passwords Of Approximately Minimum Equal Security, Sourav Bhuyan

All Theses

System-generated or user-generated text-based passwords are commonly used by the users to authenticate access to their electronic assets. These passwords may vary in usability and memorability depending on the type of password generation, composition and length. However, little past research has compared usability and memorability of passwords, satisfying minimum entropy for a secure password. This study compared three password policy conditions, assigning/generating passwords of approximately equal minimum security, i.e. 6-character alphanumeric system-generated passwords, minimum 8-character restricted user-generated passwords and minimum 16-character unrestricted user-generated passwords.
The study involved 54 participants, equally divided into three groups, 18 in each password policy condition. …

Magic Meat, Adam Stewart

All Theses

Have you ever been really secure in what it means to be? If not, it's ok. If so,
don't be delusional. Either way, I have created a series of devices that present the
challenges of self-division and fluctuation, and reveals this complicated human
characteristic not as a product of being broken, fractured, and dysfunctional, but as an
advantageous ability to adopt complex multiple perspectives, sometimes simultaneously.
These devices can be thought of as 'gym equipment' to exercise the more
immaterial, invisible portions of ourselves. Strengthening the connections between
physicality and the mental/emotional aspects of our bodies demonstrates an ability to …

Effect Of Selected Phase Change Materials Concentration And Manufacturing Process On The Properties Of Plaster Mixture Systems, Rong Cui

All Theses

Phase change materials (PCM) are generally used in building construction materials for their ability to absorb and release large amounts of energy when their phase change happens at their specific melting temperature. This results in a significant increase in thermal mass of the building, a reduction in temperature fluctuations and therefore a reduction in heating and cooling loads. However, in order to properly select a PCM and optimize its integration in a specific building, the properties of building construction materials enhanced with PCM must be known. This research focuses on studying the effects of the concentration of a micro-encapsulated PCM …

Chlorine Absorption Utilizing Caustic Sodium Sulfite, Henry Mcdonald

All Theses

A scrubber was required to abate a waste stream containing chlorine gas created in the electrolytic dissolution step of the aqueous polishing process at the Mixed Oxides Fuel Fabrication Facility at Savannah River Site, South Carolina. A method of absorption that utilized caustic sodium sulfite as the scrubbing agent was studied for implementation in the process. This method was found to be highly efficient with respect to process requirements, and it was also found to provide enhanced performance over the more conventional method of chlorine scrubbing which uses only aqueous sodium hydroxide as a reagent. Sulfite provides an additional advantage …

A Comparison Of The Performance Of Neural Q-Learning And Soar-Rl On A Derivative Of The Block Design (Bd)/Block Design Multiple Choice (Bdmc) Subtests On The Wisc-Iv Intelligence Test, Charreau Bell

All Theses

Teaching an autonomous agent to perform tasks that are simple to humans can be complex, especially when the task requires successive steps, has a low likelihood of successful completion with a brute force approach, and when the solution space is too large or too complex to be explicitly encoded. Reinforcement learning algorithms are particularly suited to such situations, and are based on rewards that help the agent to find the optimal action to execute given a certain state. The task investigated in this thesis is a modified form of the Block Design (BD) and Block Design Multiple Choice (BDMC) subtests, …

Laminar Flame Speed Estimation From Experimental Data Using A Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines, Akash Desai

All Theses

The goal of this research is to develop a thermodynamic simulation of spark-ignition engine combustion that uses a predictive burn-rate model. Previously done thermodynamic engine simulations in MATLAB are based on a specified burn rate model. Also, the effect of turbulence parameters on the rate of mass burn up is not considered. A predictive burn rate model is necessary to study the effect of different fuels on spark ignition engine combustion. The effect of laminar flame speed and turbulent intensity on combustion is difficult to assess experimental due to the difficulty in the measurement of these two variables. Thus, the …

An Analysis Of Managerial Retention Decisions Using Major League Baseball, William Ward

All Theses

Major League Baseball managers are often blamed for the poor performance of a baseball team. In the past two years alone, there have been eight midseason managerial firings and six postseason managerial firings. While this number may seem high, these numbers have actually been consistent with probabilities of managerial retention since 1930, when baseball was still in the early stages of its development as a professional sport. In the following study, I examine the factors that are taken into account during these managerial firing decisions and what conditions are present when changes do take place. Using Major League Baseball managerial …

Use Of The Health Belief Model To Assess Hand Hygiene Knowledge, Perceptions, And Practices Of Saudi Students Studying In The U.S., Najla Khateeb

All Theses

Many factors influence hygiene but those that have the greatest impact vary widely across population groups. Our aim was to characterize hand hygiene practices of Saudi students studying in the U.S. by completing two objectives: (1) assess hand hygiene knowledge, perceptions, and practices of Saudi students studying in the U.S. and (2) determine the relationship among knowledge, perceptions, and practices.
A modified version of the Health Belief Model was the theoretical framework to characterize hand hygiene practices. A web-based instrument was posted to the ¬DSaudis Studying in USAÁÂ Facebook page. The instrument was prepared in English then translated into Arabic. …

Rigging And Texturing Considerations For The Short Film Spider Fight, Casey Johnson

All Theses

This paper delves into two separate production areas of the short film, Spider Fight: the approach used to solve the problem of rigging eyelids for 3d characters, and the pipelines that were implemented for texturing 3d assets. Typically, problems exist in the rigging of eyelids for 3d characters. Productions rely on a series of blend shapes, or a combination of joints and blend shapes, to produce satisfactory eyelid movement. Spider Fight, however, used a series of curves and joints to control the movement of the eyelids, which allowed a high degree of control over eyelid movement, and also fast editing …

A Comparison And Evaluation Of Three Different Pose Estimation Algorithms In Detecting Low Texture Manufactured Objects, Robert Kriener

All Theses

This thesis examines the problem of pose estimation, which is the problem of determining the pose of an object in some coordinate system. Pose refers to the object's position and orientation in the coordinate system. In particular, this thesis examines pose estimation techniques using either monocular or binocular vision systems.
Generally, when trying to find the pose of an object the objective is to generate a set of matching features, which may be points or lines, between a model of the object and the current image of the object. These matches can then be used to determine the pose of …

Sensory Spaces, Thomas Schram

All Theses

We are all products of our environments and simultaneously have the ability to shape and change those environments. Physical environments obviously influence how we perceive and understand ourselves in relation to our surroundings, but non-physical environments have an ever-increasing effect as well. Changing technologies and increased use of online networks pose new questions about how we understand and relate to the settings we inhabit. Inspired by the work of Sherry Turkle, my work examines the tension in the transition many people experience as they incorporate more internet-ready, globally connected technology into their daily lives. I examine the intersection between virtual …

Parallel Implementation Of The Singular Value Decomposition Using Opencl, Bhushan Rayrikar

All Theses

General-Purpose Graphics Processing Units (GPGPUs) have massively parallel computational capabilities. Low cost and ease of programming make them a popular choice over other parallel architectures such as large clusters and accelerators such as Field-Programmable Gate Arrays (FPGAs). Mature programming frameworks for GPGPUs, such as CUDA from Nvidia and OpenCL from the Khronos Group, reduce the learning curve and development time for programming GPGPU architectures. OpenCL, a relatively new industry standard for parallel computing makes it possible to write a single program for heterogeneous platforms that is portable across multiple platforms including GPGPUs and multi-core processors with minimal coding modifications.
GPGPU …

Investigation Of A Novel Method For Polonium-210 Determination In Groundwater, Tara Matheny

All Theses

A novel method was investigated for the quantification of 210Po in water as an alternative to the standard method of spontaneous plating onto Ag disks followed by quantification with an alpha spectrometer. The novel method concentrated a 0.5L sample by MnO2 co-precipitation followed by dissolution of the precipitate into a solution. Polonium-210 was separated from the solution and quantified in a column containing a 50:50 by volume mixture of Pb resin (Eichrom Technologies, Inc.) mixed with granulated CaF2:Eu scintillator. The column containing 210Po is quantified on a liquid scintillation counter without the introduction of liquid cocktail. The minimum detectable concentration …

Product And Process Based Assembly Time Estimation In Engineering Design, Michael Miller

All Theses

This thesis presents the research and development of two assembly time estimation techniques for the automotive industry. Both of these techniques are capable of being implemented early in the product life-cycle of a vehicle and require information available in this phase. Currently, assembly time estimation is performed after production has begun and is a tedious manual process requiring hours of motion-time method studies for each assembly activity. The techniques proposed in this thesis can both be performed prior to the start of production and are capable of being performed automatically after the initial mapping.
The first assembly time estimation technique …

Practicing Orthodontists' Use And Perceived Efficacy Of Self-Ligating Brackets, John-David Beuhler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction.

The purpose of this study was to compare perceptions of efficacy and efficiency of Self-Ligating Brackets vs. conventional brackets between practicing Orthodontists and Orthodontic Residents.

Methods.

Cross-sectional survey research using a three-wave emailing of addresses from the current American Association of Orthodontists directory. The directors of all orthodontic residency programs in the US were asked to also distribute to all residents. The survey included five sections: (1) respondents' experience, (2) factors that influence, (3) positive or negative factors, (4) the perceived efficiency/efficacy, and (5) demographics. A 39% response rate (N=707) was obtained.

Results.

Over half (51.8%) …

Global And Specific Controls Of Protein Synthesis In Hibernators, Peipei Pan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mammalian hibernation is a highly dynamic physiological process that is composed of a series of torpor bouts, wherein hibernators oscillate between periods of torpor and interbout arousal. Although normally vital to homeostasis, many energetically consumptive processes such as translation or protein synthesis are virtually ceased during hibernation. Earlier studies indicated that protein synthesis had fallen to almost negligible levels. Cap-dependent initiation of translation is well regulated by eukaryotic translation initiation factor 4E (eIF4E) and its binding partner eIF4E-binding protein 1 (4E-BP1) when hibernators cycle in and out the torpor state. Herein, I investigated well-characterized regulatory mechanisms of global and specific …