Engineering Commons^™

Expierience, Seong Bo Chang, Albert Chen, Emily Nguyen

Computer Engineering

The name of this project is called “exPIERience” and the technological field of focus is virtual reality. We will be working on creating a virtual reality experience using the Oculus Rift for the Center of Coastal Marine Sciences (CCMS). The purpose of this system is to enable people to experience diving at the Cal Poly Pier even during nonoptimal diving conditions which occur frequently. CCMS hopes to attract further interest and possible momentum in future outreach such as a “Live Dive” program, where live videos of divers under the pier can be streamed. A 360° video from the diver’s perspective …

Integration Of Macro-Fiber Composite Material On A Low Cost Unmanned Aerial System, May Chong Chan

Doctoral Dissertations and Master's Theses

The development, deployment, and operation of Unmanned Aerial Systems (UAS) have grown exponentially in recent years and have provided researchers with the opportunity to gain hands-on experience with aircraft in a manner that was previously limited to institutions and companies with large budgets. This allows the generation and testing of UAS advanced technologies using low cost systems. The scope of this thesis does not aim to make vast improvements to the control strategy itself, but to expand upon previous UAV work carried out at Embry-Riddle by designing, implementing, and demonstrating a simulation environment for mechanical and Macro-Fiber Composite (MFC) actuated …

Performance Analysis Of A Coaxial Helicopter In Hover And Forward Flight, Stanrich D. Fernandes

Doctoral Dissertations and Master's Theses

The performance of a coaxial rotor system has been analyzed by establishing a proper basis of comparison between a conventional single rotor and coaxial rotor. An attempt has also been made to better understand the complicated aerodynamic interactions associated with coaxial rotor wakes by using a free-vortex methodology (FVM). The FVM is a Lagrangian-based wake convection methodology, which solves for the evolution of the vortical wake produced by the rotor blades under the influence of an external flow. The extent to which the two rotors interact with each other was found to be highly dependent on the inter-rotor spacing. To …

Battery Centric Serial Hybrid Aircraft Performance And Design Space, Lenny Gartenberg

Doctoral Dissertations and Master's Theses

The design space and flight envelope of a battery centric serial hybrid aircraft has been analytically derived. The formulation assumes cruising flight only and all energy available is used. The flight envelope can be generated for any conventional propeller driven serial hybrid aircraft. The advantageous combination of an electric motor and controllable-pitch electric propeller was also explored. The results are used to be able to control efficiency and noise at constant thrust and therefore constant airspeed. Manufacturer provided electric motor and propeller data is used for efficiency purposes. Since the electric motor is virtually silent compared to the propeller, published …

Robust Optimization And Groundwork For Problem Mapping, Leo Austin Ghelarducci

Doctoral Dissertations and Master's Theses

Goals of this research were to develop a conceptual algorithm that can optimize execution time for generating a solution set and demonstrate that a solution set of one sub-problem can be applied to another sub-problem within the same problem set. To achieve the proposed goals, GloPro was developed to generate rule sets for different sub-problems within a problem set, as well as identifying which rule sets are to be utilized for a given instance of the problem. The algorithm was to be robust, as to be applicable to a wide array of problems without radical re-design per problem. This idea …

Structural Design Of A Business Jet Winglet, Jaime Gutierrez

Doctoral Dissertations and Master's Theses

Structural sizing of a winglet for the Falcon 10 was performed and is presented here. The aerodynamic profile of the winglet was taken from a previous study, which predicted an increase in range of 3.3% with an estimated weight increase of 52 kg. An investigation of the current structure layouts and materials used in the industry was conducted. Six loading cases were analyzed to identify the most critical for the winglet, found to be negative and positive sideslip and gust. A finite element model was developed and used to size the structure. A fabrication process and assembly is described and …

Comparison Of Rans Modeling To Dual-Plane Piv Measurements Of The Turbulent Tip Vortex Trailed From A Hovering Rotor, Zachary Lietzau

Doctoral Dissertations and Master's Theses

Numerical simulations using the Reynolds-Averaged Navier-Stokes (RANS) equations were conducted to study the development and turbulent decay of the tip vortices in the wake produced by a hovering rotor. The computational results were compared to detailed, dual plane Particle Image Velocimetry (PIV) measurements of a turbulent tip vortex trailed from a single-bladed rotor. The work investigated both the required mesh resolution and most suitable turbulence closure models with rotational/curvature corrections by assessing their predictions of the tip vortex properties and the overall physical nature of the rotor wake. It was found that even when using a higher-order accurate central differencing …

Electrical Optimization Of A Plug-In Hybrid Electric Vehicle, Andre J. Napier

Doctoral Dissertations and Master's Theses

Hybrid electric vehicles electrification and optimization is a prominent part of today’s automotive industry. GM and the Department of Energy challenge 16 universities across North America to redesign a Chevrolet Camaro into a hybrid electric vehicle. This thesis will address how Embry Riddle Aeronautical University’s EcoCAR team electrified and optimized the vehicle. The objective of the thesis is to optimize the electric portion of the vehicle, particularly the low voltage circuitry. Prior work is discussed in detail on the vehicle communication bus, building the power distribution unit and the approach the electrical team took when building the electric portion of …

Development Of An Emulated Free-Floating Environment For On-Earth Testing Of Space Robots, Narendran Muraleedharan

Doctoral Dissertations and Master's Theses

The ability to perform experiments on space robotic systems within a laboratory setting is crucial to development and testing of satellites and space robots prior to launch. One of the most widely used techniques which recreate the on-orbit motion of space robots and targets is hardware-in-the-loop simulation. This method requires extensive knowledge of the space robot model dynamic parameters. This research proposes a method which uses force feedback to control a robotic platform on which the space robot is mounted. The robotic platform is driven in such a way that the gravity-compensated forces and torques at the mounting interface are …

Extended Surface Heat Transfer Coefficients Via Endwall Temperature Measurements, Yogesh Pai

Doctoral Dissertations and Master's Theses

Short pins are used for internal cooling of the trailing edge in a gas turbine blade. A novel method is described in this thesis which helps in simplifying the experimental process used to obtain average heat transfer data on the pin surface, at the expense of additional post processing complexity. The method is based on a unique, analytical solution of the longitudinal conduction equation with internal heat generation, allowing computation of heat transfer rates via pin base temperature measurements via Temperature Sensitive Paint, or similar non-intrusive methods. Verification of this method is done with comparisons to the solution of infinite …

Ab Initio Computation Of Radiative Properties Of Monatomic Hydrogen, Fanny Thomas

Doctoral Dissertations and Master's Theses

With renewed interest in planetary atmospheric entry, descent, and landing, NASA has noted a need for improved physics modeling in computational fluid dynamics. Uncertainty in experimental data used in radiation heat transfer computations leads to “over-engineering” of entry body heat shields, at large weight and cost penalties. There is interest in developing hypersonic thermophysics models from the known “first principles” of physics.

A method for computing high temperature gas emissivity and absorptivity from quantum mechanics principles is developed. The Schroedinger wave equation is cast as a discretized matrix eigenvalue problem which is solved using the ERAU parallel supercomputer. The numerical …

Applications Of The Technology Acceptance Model To Integration Of The Automatic Ground Collision Avoidance System In Fighter Aircraft Operations, Casey Richardson

Doctoral Dissertations and Master's Theses

The leading cause of F-16 fighter aircraft and fighter pilot losses is ground collisions. In an effort to curb this hazard, an automatic ground collision avoidance system (AGCAS) was formally fielded for use in routine U.S. Air Force active-duty F-16 operations in 2014. AGCAS uses a high-level automation design capable of altering the aircraft’s flight control system independent of pilot action.

This study explored an application of the Technology Acceptance Model (TAM) to integration of the AGCAS in fighter aircraft operations. Using data from a survey of active-duty U.S. Air Force F-16 operational fighter pilots (n=142), collected shortly after initial …

The Effect Of Surface Materials And Morphology On Wingsuit Aerodynamics, Timothy Allen Sestak

Doctoral Dissertations and Master's Theses

This study examines the aerodynamic effects of the materials, textiles, and morphologies currently used in wingsuit design and construction. The experiment was a low-speed wind tunnel investigation using a rigid wing with an aspect ratio of 2, a NACA 4418 airfoil cross section and a smooth, polished painted surface as a baseline. The baseline wing was modified by covering the upper and lower surfaces with various textiles currently used in wingsuit construction. This study is the first step in continued research to design and build a wingsuit with superior glide performance compared to current designs. Surface textures and features on …

Re-Evaluation Of Acceptance Testing Criteria For Structural Masonry Using The Prism Test Method, James Bristow

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current acceptance criteria for structural masonry in accordance with International Building Code allows for the prism test method to be used. However, without a proper understanding of the effects of variable material properties such as individual masonry unit compressive strength and the various material moduli of elasticity, as well as the effect of field conditions on the unit’s performance, masonry prisms may “fail” to reach the design compressive strength (f’m).

By identifying causes of failure and evaluating the failure magnitude, it is concluded that when the masonry prism test method is utilized for acceptance testing of as-built masonry structures, …

Fast Neutron Detection In Nuclear Material Photofission Assay Using A 15 Mev Linear Electron Accelerator, Matthew Steven Hodges

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to use a 15 MeV (K15 model by Varian) linear electron accelerator (linac) for the photon assay of special nuclear materials (SNM). First, the properties of the photon radiation probe were determined. The stochastic radiation transport code, MCNP5, was used to develop computational models for the linac. The spectral distribution of photons as well as dose rate contour maps of the UNLV accelerator facility were computed for several linac operating configurations. These computational models were validated through comparison with experimental measurements of dose rates.

The linac model was used to simulate the photon interrogation …

Generalized Clusterwise Regression For Simultaneous Estimation Of Optimal Pavement Clusters And Performance Models, Mukesh Khadka

UNLV Theses, Dissertations, Professional Papers, and Capstones

The existing state-of-the-art approach of Clusterwise Regression (CR) to estimate pavement performance models (PPMs) pre-specifies explanatory variables without testing their significance; as an input, this approach requires the number of clusters for a given data set. Time-consuming ‘trial and error’ methods are required to determine the optimal number of clusters. A common objective function is the minimization of the total sum of squared errors (SSE). Given that SSE decreases monotonically as a function of the number of clusters, the optimal number of clusters with minimum SSE always is the total number of data points. Hence, the minimization of SSE is …

Analysis Of The Temporal Response Of Coupled Asymmetrical Zero-Power Subcritical Bare Metal Reactor Systems, Kimberly Lynn Klain

UNLV Theses, Dissertations, Professional Papers, and Capstones

The behavior of symmetrical coupled-core systems has been extensively studied, yet there is a dearth of research on asymmetrical systems due to the increased complexity of the analysis of such systems. In this research, the multipoint kinetics method is applied to asymmetrical zero-power, subcritical, bare metal reactor systems. Existing research on asymmetrical reactor systems assumes symmetry in the neutronic coupling; however, it will be shown that this cannot always be assumed. Deep subcriticality adds another layer of complexity and requires modification of the multipoint kinetics equations to account for the effect of the external neutron source. A modified set of …

Deployment Strategies For A Fleet Of Unmanned Aerial Vehicles Providing Cellular And Data Services, Nima Mohseni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Wireless voice and data communications have become an essential part of our day to day lives. In order to provide these services to as many people as possible, a great infrastructure has been put in place over the last two decades throughout the world. The current infrastructure is mainly consists of cellular towers with gateways to the telecommunication backbone. The wireless infrastructure is doing an adequate job of providing voice and data services, getting more powerful and efficient every day. However, because wireless infrastructure is mainly based on fixed cell towers, it lacks the flexibility and dynamism that may be …

Novel Methods For The Time-Dependent Maxwell’S Equations And Their Applications, Sidney Shields

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigates three different mathematical models based on the time domain Maxwell's equations using three different numerical methods: a Yee scheme using a non-uniform grid, a nodal discontinuous Galerkin (nDG) method, and a newly developed discontinuous Galerkin method named the weak Galerkin (WG) method. The non-uniform Yee scheme is first applied to an electromagnetic metamaterial model. Stability and superconvergence error results are proved for the method, which are then confirmed through numerical results. Additionally, a numerical simulation of backwards wave propagation through a negative-index metamaterial is given using the presented method. Next, the nDG method is used to simulate …

Calibration Of Microscopic Traffic Flow Models Enabling Simultaneous Selection Of Specific Links And Parameters, Kul Prasad Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study proposes a methodology for the calibration of microscopic traffic flow simulation models by enabling simultaneous selection of traffic links and associated parameters. That is, any number and combination of links and model parameters can be selected for calibration. Most calibration approaches consider the entire network without enabling a specific selection of location and associated parameters. In practice, only a subset of links and parameters are used for calibration based on a number of factors such as expert local knowledge of the system. In this study, the calibration problem for the simultaneous selection of links and parameters was formulated …

Dynamic Risk Analysis Of Construction Delays Using Fuzzy-Failure Mode Effects Analysis, Mohammadsoroush Tafazzoli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Considering the tremendous losses in the worldwide economy caused by construction delays, it is essential to invest in minimizing the risks of delays. In order to make this happen, two measures should be taken:

1) The roots and fundamental causes of delay should be identified and strategies to mitigate their risks be developed (General remedy).

2) The most significant potential causes of delay in each project should be identified and these causes should be given priority to control (Project-Specific Remedy).

The current research invests in both of the measures. To provide the general remedy, causes of delay in the construction …

Analog And Mixed Signal Verification Using Satisfiability Solver On Discretized Models, Nikita Ramesh Wanjale

UNLV Theses, Dissertations, Professional Papers, and Capstones

With increasing demand of performance constraints and the ever reducing size of the IC chips, analog and mixed-signal designs have become indispensable and increasingly complex in modern CMOS technologies. This has resulted in the rise of stochastic behavior in circuits, making it important to detect all the corner cases and verify the correct functionality of the design under all circumstances during the earlier stages of the design process. It can be achieved by functional or formal verification methods, which are still widely unexplored for Analog and Mixed-Signal (AMS) designs.

Design Verification is a process to validate the performance of the …

Hexarray: A Novel Self-Reconfigurable Hardware System, Fady Hussein

Boise State University Theses and Dissertations

Evolvable hardware (EHW) is a powerful autonomous system for adapting and finding solutions within a changing environment. EHW consists of two main components: a reconfigurable hardware core and an evolutionary algorithm. The majority of prior research focuses on improving either the reconfigurable hardware or the evolutionary algorithm in place, but not both. Thus, current implementations suffer from being application oriented and having slow reconfiguration times, low efficiencies, and less routing flexibility. In this work, a novel evolvable hardware platform is proposed that combines a novel reconfigurable hardware core and a novel evolutionary algorithm.

The proposed reconfigurable hardware core is a …

Objective Assessment Of Perceptual Audio Quality Using Visqolaudio, Colm Sloan, Damien Kelly, Naomi Harte, Anil C. Kokaram, Andrew Hines

Conference papers

Digital audio broadcasting services transmit substantial amounts of data that is encoded to minimize bandwidth whilst maximizing user quality of experience. Many large service providers continually alter codecs to improve the encoding process. Performing subjective tests to validate each codec alteration would be impractical, necessitating the use of objective perceptual audio quality models. This paper evaluates the quality scores from ViSQOLAudio, an objective perceptual audio quality model, against the quality scores of PEAQ, POLQA, and PEMO-Q on three datasets containing fullband audio encoded with a variety of codecs and bitrates. The results show that ViSQOLAudio was more accurate than all …

Beer, Booze, And Biofuels: An Introduction To Chemical Engineering, Kayla Revelle, Jacob Lambert, Kelly Kopchak

Senior Theses

The goal of this thesis project was to provide the layout, curriculum, and scheduling for an introductory course regarding chemical engineering for non-majors. Throughout the course of our studies in chemical engineering and engineering in general it had come to our attention that there were many myths regarding the classes and curriculum. We had heard countless times things such as “I am glad I’m not an engineering major”, “those classes seem so hard and boring”, or “It’s all math”. The purpose of this project and class was to dispel those myths and show non-majors what chemical engineering is all about. …

Sec-Butanol From Crude Butene Feedstock Plant Design, Samantha How, Jacob Przywara, Bryce Robbins, Gavino Valdez

Senior Theses

Sec-butanol, C4H10O, is a flammable alcohol that is widely used as a fuel additive or as a reactant to make butanone, an industrial solvent. A hydration reaction between n-butenes and water, catalyzed by sulfuric acid, is a commonly used process in producing sec-butanol. However, a more challenging reaction and separation scheme is presented with a crude feedstock of butenes because of the abundance of azeotropes produced by side reactions. The development of a new plant design is relevant to industrial chemical plants that produce large amounts of crude butene side products, and can be useful by increasing plant efficiency and …

Effect Of Storage Temperature And Time On Lyophilized Water Bark Extract's Biological Activity, Jillian Schneider

Biological and Agricultural Engineering Undergraduate Honors Theses

Sweetgum bark extract has been known to show biological activities such as antimicrobial and antioxidant capabilities. The storage capacity of the extract, however, was unknown and previously thought to diminish over time. However, upon experimentation, the freeze-dried sweetgum bark extract showed no signs that storage time or storage temperature had any significant effect on the biological activities. There was no significant difference across storage temperature over time in the experiment (ANOVA RM, P0.05). Therefore, the antioxidant capabilities of the sweetgum extract were not affected by the storage time or temperature treatments studied in this work. For the antimicrobial experiment, there …

Analysis Of Lid Implementation To Combat Flooding And Erosion At The University Of Arkansas Campus, Madison E. Crowl

Biological and Agricultural Engineering Undergraduate Honors Theses

The city of Fayetteville, Arkansas has experienced rapid urbanization throughout recent years as it continues to grow. Within the city, the University of Arkansas has been constantly expanding, with increased impervious surfaces as more parking lots and facilities are built. This has caused issues including flooding and stream bank erosion, specifically in Mullins Creek, which receives runoff from a large part of campus. A portion of the creek was restored, but there are still downstream issues. Low Impact Development (LID) is a type of green infrastructure that has been shown to decrease runoff and increase infiltration. EPA SWMM, a hydrologic …

Hardware Realization Of A Residential Static Var Compensator, Muhammad Kamran Latif

Boise State University Theses and Dissertations

Conservation by Voltage Reduction (CVR) is the implementation of a distribution voltage strategy whereby all distribution voltages are lowered to the minimum allowed by the equipment manufacturer. This strategy is rooted in the fact that many loads consume less power when they are fed with a voltage lower than nominal. Electric utility companies consider CVR as a potential solution for managing power in distribution networks. However, a difficult challenge is to keep end-of-line (EOL) voltages within an acceptable range of the ANSI Standard C84.1. Therefore, to achieve maximum benefit from CVR, electric utilities should be able to regulate residential voltages …

A Comprehensive Resilience Framework For The Seismic Evaluation Of Hydraulic Fill Dams In North Texas, Santiago R. Caballero

Civil Engineering Dissertations - Archive

Hydraulic filling is a construction procedure that was used for earthen structures during the mid-1800s to the early 1900s; however, dams and levees that were constructed by implementing this technique had a significant potential for geotechnical hazards. Historically, most of the failures of these structures were a result of the soil cyclic liquefaction phenomenon. This phenomenon occurs when excess pore water pressure develops during cyclic loading and causes loss of effective strength in the soil. The cyclic stress approach is one of the methods widely used to assess cyclic liquefaction; however, seismic parameters (loading conditions) and soil characterization (liquefaction resistance) …