Engineering Commons^™

Performance Analysis Of Hybrid Algorithms For Lossless Compression Of Climate Data, Bharath Chandra Mummadisetty

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate data is very important and at the same time, voluminous. Every minute a new entry is recorded for different climate parameters in climate databases around the world. Given the explosive growth of data that needs to be transmitted and stored, there is a necessity to focus on developing better transmission and storage technologies. Data compression is known to be a viable and effective solution to reduce bandwidth and storage requirements of bulk data. So, the goal is to develop the best compression methods for climate data.

The methodology used is based on predictive analysis. The focus is to implement …

Sound Attenuation Of Fiberglass Lined Ventilation Ducts, Jacob Albright

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sound attenuation is a crucial part of designing any HVAC system. Most ventilation systems are designed to be in areas occupied by one or more persons. If these systems do not adequately attenuate the sound of the supply fan, compressor, or any other source of sound, the affected area could be subject to an array of problems ranging from an annoying hum to a deafening howl. The goals of this project are to quantify the sound attenuation properties of fiberglass duct liner and to perform a regression analysis to develop equations to predict insertion loss values for both rectangular and …

Object Detection And Tracking In Wide Area Surveillance Using Thermal Imagery, Santosh Bhusal

UNLV Theses, Dissertations, Professional Papers, and Capstones

The main objective behind this thesis is to examine how existing vision-based detection and tracking algorithms perform in thermal imagery-based video surveillance. While color-based surveillance has been extensively studied, these techniques can not be used during low illumination, at night, or with lighting changes and shadows which limits their applicability. The main contributions in this thesis are (1) the creation of a new color-thermal dataset, (2) a detailed performance comparison of different color-based detection and tracking algorithms on thermal data and (3) the proposal of an adaptive neural network for false detection rejection.

Since there are not many publicly available …

Fast Transient Digitizer And Pcb Interface, Kevin Thomas Buck

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis outlines the design, layout and characterization of an application specific integrated circuit (ASIC) and a printed circuit board (PCB) designed to discretize an input signal and read out the data at a user desired interval to replicate the input signal at a lower frequency or pulse rate with no quantization error. The ASIC for this task utilizes 128 individual capacitive storage cells to capture data at approximately 200 ps intervals, thus the chip can capture approximately 25 ns of an input signal. The read out rate can be adjusted to the desired rate by the user by changing …

Chemical And Electronic Structure Of Surfaces And Interfaces In Cadmium Telluride Based Photovoltaic Devices, Douglas Arthur Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The surface and interface properties are of the upmost importance in the understanding, optimization, and application for photovoltaic devices. Often the chemical, electronic, and morphological properties of the films are empirically optimized, however when progress slows, a fundamental understanding of these properties can lead to breakthroughs. In this work, surfaces and interfaces of solar cell-relevant films are probed with a repertoire of X-ray analytical and microanalysis techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), X-ray emission (XES) spectroscopies, and atomic force (AFM) and scanning electron (SEM) microscopies.

Silicon-based devices currently dominate the solar market, which is rather inflexible …

Safety Analysis Of Freeway Segments With Unobserved Heterogeneity And Second Order Spatial Effects, Eneliko Mujuni Mulokozi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Safety analysis of freeway networks entails the quantification of crash frequency influencing factors which include roadway and traffic characteristics, environmental factors as well as human factors. This quantification can be used to detect locations with large impacts on the occurrence of crashes which in turn assist engineers and planners to improve safety levels of the network. Roadway characteristics are comprised of the physical elements of the road geometry such as section length, median and right shoulders, speed-exchange lanes, the number of main facility as well as geometry of the entrance from and exit to the main freeway facility. Traffic characteristics …

A Multi-~Procedural Approach To Evaluating Walkability And Pedestrian Safety, Peris Nyagah

UNLV Theses, Dissertations, Professional Papers, and Capstones

Walking has sound health benefits and tends to be a pleasurable experience requiring no fuel, fare, license, nor registration. Whilst walking is recommended as part of physical activity, it is necessary to provide a conducive and safe walking environment. In an effort to determine an optimum combination of infrastructure that would create walkable, transit-oriented neighborhoods eliminating unnecessary motorized trips; various approaches evaluating an assortment of features in the walking environment have been implemented. However, some factors such as crash risk which have an essential contribution to the suitability of the walking environment have yet to be considered. Therefore the objective …

Compression Of Climate Data Through Artificial Neural Networks, Astha Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lately, there has been a tremendous increase in the number of climate monitoring

stations in various parts of the country producing abundant climate data. Among climate data parameters, humidity and temperature are the two parameters influencing hydrological and agricultural processes, weather monitoring, and having critical effect on living organisms. As more data is being generated over time, there is a strong need to develop compression methods for efficient transfer and storage of this data.

The main goal of this thesis is to perform compression of humidity and temperature

data via prediction. As these are critical components of climate, it is …

An Approach To Model Plastic Deformation Of Metallic Plates In Hypervelocity Impact Experiments, Shawoon Kumar Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Space structures are subjected to micro-meteorite impact at extremely high velocities of several kilometers per second. Similarly, design of military equipment requires understanding of material behavior under extremely high pressure and temperature. Study of material behavior under hypervelocity impact (HVI) poses many challenges since few researchers so far have approached this problem. Material models, equations of the state, and fracture mechanics are not well understood under these conditions.

The objective of this research is to present an approach for studying plastic deformation of metallic plates under HVI conditions. A two-stage light gas gun can be used to simulate these conditions …

The Comparison Of Two Supine Manikins And The Use Of A Shock And Vibration Isolation System For Litter Patients In Air Medical Transport, Karina Karlui Saenz Acosta

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studies show that repeated shock and vibration during aero medical and ground transport are causing patient pain and may be adversely affecting patients’ medical outcome. Patients with spine and head injuries and other severe neurological injuries are the most vulnerable to repeated shock and vibration exposure caused by the vehicle. It is crucial to minimize the effects of these forces on patients during air and ground medical transport. The development of new medical evacuation platforms creates a need to better understand the effects of human exposure to shock and vibration. The use of human subjects to measure whole body vibration …

Alkali-~Activated Fly Ash Binders: Feasibility As A Sustainable Alternative To Ordinary Portland Cement For Pre-~Cast Systems, Kimberly Sierra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fresh, load-dependent, transport, and durability properties of alkali-activated fly ash mortars were studied. The influences of activator concentration, solution-to-binder ratio, curing condition, activator type, and sodium silicate-to-total solution ratio on the properties of the studied alkali-activated mortars were examined. This study was divided in two phases. The first phase dealt with the use of sodium hydroxide as the sole activator. The second phase of the study was divided into two parts, both of which used a combination of sodium hydroxide and sodium silicate as the activator solution. Part I of phase II used elevated temperature curing conditions, whereas part II …

Crystalline Phase Change In Steel Alloys Due To High Speed Impact, Muna Slewa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The effect of hypervelocity projectile impact on the crystalline grain structure near the target impact location of A36 steel has been studied. A36 steel is a mostly single phase body centered cubic material (BCC). Impact velocities ranged from 3.54 to 6.70 km/sec. Target materials were studied before and after impact to determine if these impact conditions result in a phase change of the A36. Scanning electron microscopy, electron back-scatter diffraction, and x-ray diffraction methods were used to investigate deformation, lattice defects, twinning, and phase transformation. A limited number of impacted targets made from 304L and HY100 steels were also examined. …

Simulation Of An Air Cooled Single-Effect Solar Absorption Cooling System With Evacuated Tube Collectors, Mohsen Jahandardoost

UNLV Theses, Dissertations, Professional Papers, and Capstones

Consistently increasing CO2 emission and ozone depletion from synthetic refrigerants are serious environmental issues challenging the scientific community. Absorption cooling systems give scope of utilizing low grade energy source for generating cooling effect. Solar energy is one of these low grade energy sources and with considering the fact that cooling demand increases with the intensity of solar radiation, solar refrigeration has been considered as a logical solution.

This thesis consists of two different simulation stages, in the first stage, a single effect lithium bromide absorption cooling system with constant cooling capacity is modeled and the effect of ambient and generator …

The Influence Of Iron On Arctic Thule Migration Patterns, Alina T. Aquino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Arctic scholars have yet to fully understand the reasons behind the migration of Thule culture from the western to the eastern Arctic. This rapid movement across such a vast area into environmentally diverse regions marks a critical period of cultural change that is usually summarized by two theoretical positions. Ecological theories postulated environmental changes placed selective pressures on traditional food sources that required Thule hunters to follow migrating prey. Theories that focused on material acquisition alternately proposed the Thule followed the trail of meteoric iron eastward into northwestern Greenland.

This research sought to examine the eastward Thule migration from another …

Study Of Machine Learning Methods In Intelligent Transportation Systems, Vishal Jha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Machine learning and data mining are currently hot topics of research and are applied in database, artificial intelligence, statistics, and so on to discover valuable knowledge and the patterns in big data available to users. Data mining is predominantly about processing unstructured data and extracting meaningful information from them for end users to help take business decisions. Machine learning techniques use mathematical algorithms to find a pattern or extract meaning out from big data. The popularity of such techniques in analyzing business problems has been enhanced by the arrival of big data.

The main objective of this thesis is to …

Designing, Building And Testing A Solar Thermoelectric Generation, Steg, For Energy Delivery To Remote Residential Areas In Developing Regions, Yacouba Moumouni

UNLV Theses, Dissertations, Professional Papers, and Capstones

New alternatives and inventive renewable energy techniques which encompass both generation and power management solutions are fundamental for meeting remote residential energy supply and demand today, especially if the grid is quasi-inexistent. Solar thermoelectric generators can be a cost-effective alternative to photovoltaics for a remote residential household power supply. A complete solar thermoelectric energy harvesting system is presented for energy delivery to remote residential areas in developing regions. To this end, the entire system was built, modeled, and then validated with LTspice simulator software via thermal-to-electrical analogy schemes. Valuable data in conjunction with two novel LTspice circuits were obtained, showing …

Development Of A Decision Support Framework For The Planning Of Sustainable Transportation Systems, Pankaj Maheshwari

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the rapid increase in economic development throughout the world, there is stress on the resources used to support global economy, including petroleum, coal, silver, and water. Currently, the world is consuming energy at an unprecedented rate never seen before. The finite nature of such non-renewable natural resources as petroleum and coal puts pressure on the environmental system, and ultimately reduces the availability of resources for future generations. Hence, it is critical to develop planning and operational strategies that seek to achieve a sustainable use of existing natural resources.

With this motivation, this dissertation focuses to develop a decision support …

Robust Observability, Control, & Economics Of Complex Cyber-Physical Networks, Shaurya Agarwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with various aspects of cyber-physical system. As an example of cyber physical systems, we take transportation networks and solve various problems, namely: 1) Network Observability Problem, 2) Network Control Problem, and 3) Network Economics Problem. We have divided the dissertation into three parts which solve these three problems separately. First part of the dissertation presents a novel approach for studying the observability problem on a general network topology of a traffic network. We develop a new framework which investigates observability in terms of flow information on arcs and the routing information. Second part of the dissertation presents …

Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru

UNLV Theses, Dissertations, Professional Papers, and Capstones

Layered structured materials such as transition metal dichalcogenides (TMDs) have gained immense interest in recent times due to their exceptional structural, electrical and optical properties. Recent studies show semiconducting TMDs such as MX₂ (M= Mo, W & X = S, Se) could be used as potential shock absorbing material, which has resulted in extensive studies on structural stability of these materials under the influence of high pressure. Understanding the structural stability of transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2 under high pressure has been very challenging due to contradicting observations and interpretations reported in the …

Fluoride And Phosphate Removal From Industrial And Domestic Wastewaters Using Cerium Chloride, John Michael Gonzales

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of cerium chloride (CeCl3) to remove fluoride and phosphate from waters is addressed in this study. High concentrations of fluoride exist in groundwater especially in developing countries. Consumption drinking water containing high levels of fluoride can lead to serious cases of dental and skeletal fluorosis. Current defluoridation technologies are limited, especially for high levels of fluoride, and are expensive. Industrial wastewaters contribute to the highest fluoride contamination in the world. With the increasing production of electronic materials, the global fluoride concentration and fluoride-contaminated waters have grown tremendously. Excessive discharge of phosphate into the environment promotes eutrophication of lakes …

Reducing Insertion Loss Of Wavelength-Routed Optical Network Based On Microring Resonator Optical Switches, Yunjia Man

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the ever-increasing demand for high-performance computing systems, on-chip interconnection networks, serving as the communication links in multicore architectures, have become the key to the system performance. Compared with bandwidth-limited power-hungry electrical interconnection networks, optical network-on-chip (ONoC) architectures are emerging as a promising alternative to enable future computing performance gains owing to the recent advancements in silicon photonics. One major issue of ONoC is its insertion loss, which is the optical link loss along the waveguide and through the network. Once the optical power budget is established, the maximum insertion loss through the network can be determined. If insertion loss …

General Application Of Smart Inverters In Distribution And Smart Grid, Wenxin Peng

UNLV Theses, Dissertations, Professional Papers, and Capstones

The electric grid of the near future will face challenges and opportunities based on two aspects. First, the rapid growth of renewable generations expedites the upgrading of traditional electric grids, allowing more and more distributed generation connected at the customers’ side. Distributed generation units use a wide range of generation technologies, including gas turbines, diesel engines, solar photovoltaics (PV), wind turbines, fuel cells, biomass, and small hydroelectric generators. Under certain penetration level, the grid will experience issues like unexpected voltage rise as well as reverse power flows due to the fluctuation of power production of the distributed generation, especially when …

Cfd Simulation Of Heat Enhancement In Internally Helical Grooved Tubes, Sogol Pirbastami

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat exchanger devices are widely used in industries, air conditioning systems, refrigeration, etc. These devices have a major role in energy conservation; therefore, increasing the performance of heat exchangers helps save energy, costs and materials. The technique to increase the heat transfer performance is called heat augmentation, which can be applied to pipe surfaces and other surfaces which are used in heat exchangers to improve thermal performance. These techniques are categorized into 3 groups: passive, active and compound technique. In this study a helically machined rectangular groove on the inside of a 2.0 m tube with a diameter of 7.1mm …

Geotechnical Surrogates For Sediment Shear Behavior In Southern Nevada, Rinu Ann Samuel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Nevada Department of Transportation design standards for deep foundations, particularly drilled shafts, in the Las Vegas Valley (LVV) may be overly conservative due to the challenges in characterizing strong but difficult-to-sample sediment strata, such as dense gravel, heavily cemented sediments, and mixed materials, which occur commonly in the LVV. Consequently, there is a need for investigating methods to assess the shear behavior of sediments that occur in the LVV in situ in working ranges of stress/strain, with the end goal of improving abilities to predict the capacity of drilled shafts in the LVV. To this end, global correlations of …

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

3d Obstacle Avoidance For Unmanned Autonomous System (Uas), Lin Zhao

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this thesis is to design a real-time, three-dimensional algorithm, named as the vector mesh (VM) algorithm, for unmanned aerial vehicles (UAV) to generate collision-free motion in indoor or outdoor environments with unknown obstacles. This promising technology can be utilized in both military and commercial applications. The VM approach employs three data reduction phases to compute optimal navigation directions while on-board scanning range sensor continuously updates depth data. In order to develop the VM, vector filed histogram (VFH) which applied in 2D space was first simulated in Matlab. Then a 2D autonomous navigation was implemented on a developed …

Evaluating The Level Of Harmonic Distortion In A Typical Distribution Feeder, Wessen S. Bogale

UNLV Theses, Dissertations, Professional Papers, and Capstones

Steady-state analysis of electrical power systems is largely based on linear and sinusoidal AC circuits which allow the concept of impedance, phasors and well-defined power quantities (i.e., real, reactive and apparent powers). In reality, however, the electric load which was once composed of linear elements (e.g., induction motors, incandescent lighting, etc …) is becoming more and more nonlinear due to the wide-spread use of electronic components such as fluorescent lighting and variable-frequency drives that power the majority of electric motors. As a consequence, the current drawn by such devices is often distorted, thus containing a number of high frequency harmonics …

Prediction Of Shear Strength And Ductility Of Cyclically Loaded Reinforced Concrete Columns Using Artificial Intelligence, Nicholas Gordon

UNLV Theses, Dissertations, Professional Papers, and Capstones

The shear strength and deformation capacities of reinforced concrete (RC) columns are governed by a multitude of variables related to material properties of the steel and concrete used in the design and construction of the columns. Predicting performance of RC columns using design variables is a complex, non-linear problem. The prediction of shear strength and ductility for these types of structural members has historically been performed using empirically or semi-empirically derived formulae based on experimental results. The introduction of cyclical lateral loading, such as the forces imposed on a structure during an earthquake, can result in severe degradation of shear …

Bulbous Pier: Alternative To Bridge Pier Extensions, Amilcar Chavez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridge deck splashing causes deterioration to the bridge structure and renders the bridge unsafe for motorist and pedestrians. The traditional countermeasure for bridge deck splashing is pier extension, the pier extension moves the pier wave away from the bridge deck, but retrofitting existing bridges with pier extensions is costly. This research proposes the bulbous pier concept as an alternative to pier extension.

The decrease in the pier wave produced by the bulb is due to energy subtracted by the bulb via two forces, the viscous resistance, and the wave-making resistance. The proposed mathematical model for the bulbous pier design follows …

In Vitro Studies Of Gold And Gold Silica Nanoparticle Radiosensitization With Kilovoltage X-Rays, Gregory Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technological advances in the ability to construct and manipulate nanoscale particles have opened up the possibility of using solid metallic nanoparticles and mixed metal nanoshells as a means to increase dose enhancement and treatment efficacy to tumors. In order for nanoparticles to be an effective form of treatment, they must be delivered to tumors in sufficient concentrations so that there is a dose enhancement factor due to ionizing radiation, as well as being essentially non-toxic to healthy cells. Gold nanoparticles and silica-gold nanoshells fit these requirements. Gold has a high atomic number (Z=79), which gives a larger cross section for …