Engineering Commons^™

Performance Measure For Transportation Network: A Study In Travel Time Dynamics, Anuj Nayyar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Arterial Performance Measurement and Monitoring is one of the leading goals of any transportation agency. The complexity of the differences between performance measures is highlighted and the various data collection methodologies are highlighted. A major performance measure that impacts end users and traffic planners is travel time. This study presents defining a mathematical system for modeling travel time. The modeling in real-time is presented and methods are proposed to evaluate it using vehicle trajectories. Also comparative results are presented between the actual sensor data sets and simulated data to study the effectiveness of the system developed.

A Comparative Study Of Performance, Impediments, Advantages, And Disadvantages Of Construction And Professional Disadvantaged Business Enterprises, Ravi Sharma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction and professional disadvantaged, minority, and women business enterprises (DBE/MBE/WBEs) face several impediments that hinder their business growth. A questionnaire survey was conducted to determine the important factors that affect their business performance, impediments faced by these business enterprises, advantages, and disadvantages of being DBE (DBE will be an umbrella designation for DBE, MBE, and WBE). This study compares the difference in responses from these two groups. A total of 333 business enterprises responded to the questionnaire. The survey results showed that construction firms gave significantly higher importance to "financial" issues and "safe work practices" as their most important factors …

Feasibility Of The Use Of Ultrasound Measurements For Grade Verification Of The Performance Grade Asphalt Binders, Mehdi Khalili

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research investigates the feasibility of application of high frequency immersion ultrasonic measurement (UM) to discriminate different performance grade (PG) asphalt binders. PG asphalt binder is one of the main components of hot mix asphalt used for roadway construction. UT may provide an inexpensive alternative to sophisticated tests currently used for quality control of PG asphalt binders. Nine different PG asphalt binders used were selected for this investigation. Velocity (V) and integrated response (IR) of the ultrasonic wave were measured. The IR is a measure of the ratio of ultrasonic energy transmitted into the material to the ultrasonic energy reflected …

Max Operation In Statistical Static Timing Analysis On The Non-Gaussian Variation Sources For Vlsi Circuits, Abu M. Baker

UNLV Theses, Dissertations, Professional Papers, and Capstones

As CMOS technology continues to scale down, process variation introduces significant uncertainty in power and performance to VLSI circuits and significantly affects their reliability. If this uncertainty is not properly handled, it may become the bottleneck of CMOS technology improvement. As a result, deterministic analysis is no longer conservative and may result in either overestimation or underestimation of the circuit delay. As we know that Static-Timing Analysis (STA) is a deterministic way of computing the delay imposed by the circuits design and layout. It is based on a predetermined set of possible events of process variations, also called corners of …

Computer-Based Stereoscopic Parts Recognition For Robotic Applications, Ahmad A. Fayed

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most of robotic handling and assembly operations are based on sensors such as range and touch sensors. In certain circumstances, such as in the presence of ionizing radiation where most customary sensors will degrade over time due to radiation exposure, these sensors won't function properly. Utilizing two or more cameras (stereo vision) located outside the target zone and analyzing their images to identify location and dimensions of parts within the robot workspace is an alternative for using sensors. Object Recognition is affected by the light condition which oftentimes causes the gray-scale or red, green, and blue values to have a …

Impacts Of Climate Changes On The Spatiotemporal Distribution Of Precipitation In The Western United States, Peng Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Precipitation in the Intermountain West is characterized by its great variability in both spatial and temporal distributions. Moreover, the spatiotemporal distribution of the precipitation is changing due to the climate changes. In this dissertation, three studies are conducted to investigate the multi-scale temporal variability of precipitation, the performance of current climate models on this variability, the influence of large-scale ocean oscillations on heavy precipitation, and the impact of human induced global warming on storm properties.

The first study is to examine the performance of current climate models on the simulation of the multi-scale temporal variability determined from the observed station …

Study Of Seat-Belt Usage In Nevada & Driver's Performance, Atul Sancheti

UNLV Theses, Dissertations, Professional Papers, and Capstones

According to the Centers for Disease Control (CDC), motor vehicle incidents has been reported to be the leading cause of the accidental deaths in the United States accounting for more than 42,000 deaths every year. Distracted driving and Driving under influence (DUI) are the major contributors to these roadway crashes. Moreover, drivers fatigue and drowsiness behind the wheel is another important factor contributing to the high fatality rate. These factors results in significant decline in the driver's abilities of perception, recognition and vehicle control.

It has also been reported by National Highway Traffic Safety Administration (NHTSA) estimated that about 292,471 …

Performance Comparison Of Design-Build And Construction Manager/General Contractor Highway Projects, Binita Shakya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Researchers have conducted numerous studies comparing project performance of design-bid-build (DBB) and design-build (DB) highway projects. However, little research has been done to compare the performance of DB and construction manager/general contractor (CM/GC) highway projects. Therefore, an exploratory study was conducted to compare the performance of 55 DB and 34 CM/GC highway projects from various States Departments of Transportation (DOTs) in terms of cost, change orders, and construction intensity. The results showed that contract award cost growth was significantly lower in DB projects than in CM/GC projects. In contrast to this, the total cost growth of DB projects was higher …

Assessing Different Zeolitic Adsorbents For Their Potential Use In Kr And Xe Separation, Breetha Alagappan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Separation of Kr from Xe is an important problem in spent nuclear fuel fission gas management. The energy intensive and expensive cryogenic distillation method is currently used to separate these gases. In this thesis, we have carried out the research into appropriate sorbents for the separation of Kr and Xe using pressure swing adsorption. We have examined zeolites using gas adsorption studies as they have the potential to be more cost effective than other sorbents. Zeolites are microporous aluminosilicates and have ordered pore structures. The pores in zeolites have extra-framework cations are substantially free to move. The mobility of cations …

Experimental And Finite Element Studies Of Shock Transmission, Eldon Jerry Goddard

UNLV Theses, Dissertations, Professional Papers, and Capstones

Composite materials are more widely used today in engineering products than ever before. Shock transmission in jointed composite sections needs to be investigated to understand the affect of composite materials on the dynamic response of the system. There exists limited published work on transient shock propagation through composite sections. The aim of this study is to analyze the transient behavior of joints in composite materials subjected to low impact loads and to develop a computational model that provides an improved physics based shock model. The jointed connection will be investigated experimentally and using Finite Element Analysis (FEA). The bolted joint …

Evaluation Of Alternative Project Delivery Methods In Water And Wastewater Projects, Ruiko Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States (U.S.) is facing significant challenges in addressing aging water infrastructure. Most of the drinking water infrastructure is reaching the end of their useful lives. The American Water Works Association (AWWA) estimated that it will cost about $1 trillion to repair or replace drinking water pipes. Over the next 20 years, it will cost about $298 billion to fix or expand pipes of the nation's wastewater and storm-water systems (AWWA, 2012). Owners, engineers, and contractors are using Alternative Project Delivery (APD) methods - e.g., Design-Build Construction Management-at-Risk Construction Management/General Contractor- to build water and wastewater projects in order …

A Case Study Of Zero Energy Home Built For Solar Decathlon Competition 2013, Sanjib Mulepati

UNLV Theses, Dissertations, Professional Papers, and Capstones

Energy consumption in residential homes has been a subject of research related to sustainability. Reduction in the consumption of energy is a goal of sustainable construction. The Department of Energy (DOE) started a Solar Decathlon competition in 2002 in which the students from different universities around the globe build an energy efficient and affordable home suitable for their climate and location. The main goal of this competition is to select the best home that is designed and built in a sustainable way. In this study, the home designed and constructed for participation in the competition by the students at University …

On High-Performance Parallel Fixed-Point Decimal Multiplier Designs, Ming Zhu

UNLV Theses, Dissertations, Professional Papers, and Capstones

High-performance, area-efficient hardware implementation of decimal multiplication is preferred to slow software simulations in a number of key scientific and financial application areas, where errors caused by converting decimal numbers into their approximate binary representations are not acceptable.

Multi-digit parallel decimal multipliers involve two major stages: (i) the partial product generation (PPG) stage, where decimal partial products are determined by selecting the right versions of the pre-computed multiples of the multiplicand, followed by (ii) the partial product accumulation (PPA) stage, where all the partial products are shifted and then added together to obtain the final multiplication product. In this thesis, …

Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor, Jeremiah Boles

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to analyze the theoretical criticality of a spherical uranium-hexafluoride reactor with a transient, pulsed shockwave emanating from the center of the sphere in an outward-radial direction. This novel nuclear reactor design, based upon pulsed fission in a spherical enclosure is proposed for possible use in direct energy conversion, where the energy from fission products is captured through the use of electrostatic fields or through induction. An analysis of the dynamic behavior of the shockwave in this reactor is the subject of this thesis. As a shockwave travels through a fluid medium, the characteristics of …

Design And Fabrication Of An Infrared Optical Pyrometer Asic As A Diagnostic For Shock Physics Experiments, Jared Gordon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Optical pyrometry is the sensing of thermal radiation emitted from an object using a photoconductive device to convert photons into electrons, and is an important diagnostic tool in shock physics experiments. Data obtained from an optical pyrometer can be used to generate a blackbody curve of the material prior to and after being shocked by a high speed projectile. The sensing element consists of an InGaAs photodiode array, biasing circuitry, and multiple transimpedance amplifiers to boost the weak photocurrent from the noisy dark current into a signal that can eventually be digitized. Once the circuit elements have been defined, more …

Snail Algorithm For Task Allocation In Mesh Networks, Bartosz Duszel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Topic of this master's thesis is connected with task allocation algorithms and mesh networks. Author of this work has already graduated from Wroclaw, University of Technology (Poland) where during his studies he created software simulation environment for two different task allocation algorithms for mesh networks:Adaptive ScanandFrame Sliding. Those algorithms were compared by two, main parame- ters: simulation time and average mesh fulfillment (utilization level). All simulations were done in software environment which was developed specially for that research. This application was based on few, different types of objects: task (width, height, processing time), task queue (different number of tasks), task …

Nonlinear Adaptive Diffusion Models For Image Denoising, Ajay Kumar Mandava

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most of digital image applications demand on high image quality. Unfortunately, images often are degraded by noise during the formation, transmission, and recording processes. Hence, image denoising is an essential processing step preceding visual and automated analyses. Image denoising methods can reduce image contrast, create block or ring artifacts in the process of denoising. In this dissertation, we develop high performance non-linear diffusion based image denoising methods, capable to preserve edges and maintain high visual quality. This is attained by different approaches: First, a nonlinear diffusion is presented with robust M-estimators as diffusivity functions. Secondly, the knowledge of textons derived …

Robust And Adaptive Attitude Control Of Spacecraft Using Solar Radiation Pressure, Lakshmi Srinivasan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Satellites in orbit are expected to maintain a preset attitude either pointing towards Earth (in case of satellites for weather) or pointing towards space for the purpose of research and exploration. The satellite as a system though is extremely nonlinear and the system parameters are not easily available. The goal of this thesis is to develop robust and adaptive control laws that can be used to control the attitude of satellites in elliptic orbits. The attitude of the satellite is controlled by the use of Solar Radiation Pressure (SRP) on the solar panels of the satellite. The SRP is basically …

An End To End V.M.T Framework With Controlled V.M.T Tax Rate Using Optimal Feedback Control Technique, Pratik Verma

UNLV Theses, Dissertations, Professional Papers, and Capstones

Vehicle Mile Travel (VMT) is a study related to available alternatives for the road

revenue collection system. As per the demand, the existing Gas/Fuel tax based revenue

collection system is not found an appropriate option in the longer run. Due

to existing system constraints like: no eective tax process for vehicles based on alternative

fuel (e.g. electric vehicles), no eective changes in tax due to economical

ination, and more highway expenditure than generated revenue, an alternative revenue

collection mechanism is required. Hence, the objective is to study an alternative

option in detail, which can address the gaps between required revenue …

Calibration Of Microscopic Traffic Flow Models Considering All Parameters Simultaneously, Victor Hugo Molano Paz

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study proposes a methodology to calibrate microscopic traffic flow simulation models. The proposed methodology has the capability to calibrate simultaneously all the calibration parameters as well as demand patterns for any network topology. These parameters include global and local parameters as well as driver behavior and vehicle performance parameters; all based on multiple performance measures, such as link counts and speeds. Demand patterns are included in the calibration framework in terms of turning volumes.

A Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm is proposed to search for the vector of the model‟s parameters that minimizes the difference between actual and …

Phosphorus Removal From Ebpr Sludge Dewatering Liquors Using Lanthanum Chloride, Aluminum Sulfate And Ferric Chloride, Michael Strileski

UNLV Theses, Dissertations, Professional Papers, and Capstones

In wastewater treatment, enhanced biological phosphorus removal (EBPR) is becoming an increasingly popular alternative to chemical precipitation (CP) because of its lower costs and reduced sludge production. However, downstream solids handling processes such as digestion, sludge storage and dewatering promote an undesirable release (i.e. secondary release) of polyphosphate that was stored within EBPR sludge. Released phosphate is recycled to the head of the plant with the liquors of sludge dewatering processes. The concentration of phosphate in recycle streams from EBPR systems can be one to two orders of magnitude higher than the influent phosphorus concentration entering the EBPR system. Plants …

Numerical Modeling Of Heat Pipe Radiator And Fin Size Optimization For Low And No Gravity Environments, Virginia Ruth Bieger

UNLV Theses, Dissertations, Professional Papers, and Capstones

A heat-pipe radiator element has been designed and modeled to study the efficiency of heat transfer for low and no gravity environments, like in lunar environments. The advantages of using heat pipe includes the significant weight reducing and heat transfer efficiency. The heat transfer can be enhanced by the use of condenser sections with attached fins.

A series of various geometries of solid fins and heat pipes with and without fins were modeled using FLUENT®. This was done to determine the validity of using a heat pipe in lieu of a solid fin projection. A heat pipe had a 25 …

3d Modeling And Design Optimization Of Rod Shaped Ionic Polymer Metal Composite Actuator, Siul A. Ruiz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ionic polymer-metal composites (IPMCs) are some of the most well-known electro-active polymers. This is due to their large deformation provided a relatively low voltage source. IPMCs have been acknowledged as a potential candidate for biomedical applications such as cardiac catheters and surgical probes; however, there is still no existing mass manufacturing of IPMCs. This study intends to provide a theoretical framework which could be used to design practical purpose IPMCs depending on the end users interest.

This study begins by investigating methodologies used to develop quantify the physical actuation of an IPMC in 3-dimensional space. This approach is taken in …

Study Of A Non-Equilibrium Plasma Pinch With Application For Microwave Generation, Ahmad Al Agry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Non-Equilibrium Plasma Pinch (NEPP), also known as the Dense Plasma Focus (DPF) is well known as a source of energetic ions, relativistic electrons and neutrons as well as electromagnetic radiation extending from the infrared to X-ray. In this dissertation, the operation of a 15 kJ, Mather type, NEPP machine is studied in detail. A large number of experiments are carried out to tune the machine parameters for best performance using helium and hydrogen as filling gases. The NEPP machine is modified to be able to extract the copious number of electrons generated at the pinch. A hollow anode with …

Implementation Of Integrated Project Delivery On Department Of Navy Military Construction Projects, Christopher S. Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

The concept of the project delivery system refers to the overall processes by which a project is designed, constructed, and/or maintained. There are many different types of project delivery systems to fit particular situations involving the owner and his intended project. The project delivery system is what establishes the framework that enables a construction project to be developed and ultimately executed.

The construction industry has observed that projects (both private and public) frequently suffer from factors such as adversarial relationships, low roductivity, high inefficiency and rework, frequent contractual disputes concerning who was at fault, and lack of innovation. Not only …

High-Performance, Scalable Optical Network-On-Chip Architectures, Xianfang Tan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The rapid advance of technology enables a large number of processing cores to be integrated into a single chip which is called a Chip Multiprocessor (CMP) or a Multiprocessor System-on-Chip (MPSoC) design. The on-chip interconnection network, which is the communication infrastructure for these processing cores, plays a central role in a many-core system. With the continuously increasing complexity of many-core systems, traditional metallic wired electronic networks-on-chip (NoC) became a bottleneck because of the unbearable latency in data transmission and extremely high energy consumption on chip. Optical networks-on-chip (ONoC) has been proposed as a promising alternative paradigm for electronic NoC with …

An Online Algorithm For The 2-Server Problem On The Line With Improved Competitiveness, Lucas Adam Bang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis we present a randomized online algorithm for the 2-server problem on the line, named R-LINE (for Randomized Line). This algorithm achieves the lowest competitive ratio of any known randomized algorithm for the 2-server problem on the line.

The competitiveness of R-LINE is less than 1.901. This result provides a significant improvement over the previous known competitiveness of 155/78 (approximately 1.987), by Bartal, Chrobak, and Larmore, which was the first randomized algorithm for the 2-server problem one the line with competitiveness less than 2. Taking inspiration from this algorithm,we improve this result by utilizing ideas from T-theory, game …

Investigating The Feasibility Of Growing Algae For Fuel In Southern Nevada, Faegheh Moazeni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microalgae capable of growing in waste are adequate to be mass-cultivated for biodiesel, avoiding fertilizers and clean water, two obstacles to sustainability of the feedstock production. This study replaces fertilizers and clean water with waste products. The investigated wastes include (1) the liquid fraction of sewage after solids and particles are removed, known as centrate, and (2) algal biomass residue, i.e. the algae remaining at the end of the lipids extraction process at biofuel plants. These wastes contain sufficient amount of nitrogen and phosphorus required for algal growth. This study proposes a system in which centrate would be used as …

Investigation Of Crashes And Identifying The Best Practices For Setting Up Speed Zones In Towns Along Rural Highways In Nevada, Krishna Prasad Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2010, 51,664 crashes occurred in Nevada. Only about 9% of those crashes occurred in rural areas of the state. However, if only fatal crashes are considered, 41% of those fatal crashes occurred in rural areas. Generally, speed zones are provided in towns along rural highways to reduce speed-related crashes. However, a guideline is necessary for a consistent procedure to setup speed zones throughout the state. The main objectives of this study are to determine factors associated with crashes and to identify the best practices for setting up speed zones in towns along rural highways.

Eleven towns along rural highways …

Supersonic Turbine Cascade Studies Using Computational Fluid Dynamics And Water Table Experiments, Shelby E. Nelson

Honors College Theses

Design engineers use a variety of tools to perform calculations and to aid in the design process. For example, engineers designing gas turbines, specifically the aerodynamicists, use a combination of hand calculations, experimental data, and complex numerical codes to simulate air flow around each blade. Aerodynamicists designing gas turbines must predict the locations of the shocks to locate inefficiencies in the flow. In this thesis, three methods of calculating the shock angles are compared: analytical, experimental, and computational. Three different airfoil shapes are tested: a rectangular flat plate, a supersonic diamond, and a turbine airfoil. Cascade tests of the airfoil …