Engineering Commons^™

Design And Implementation Of Reconfigurable Patch Antennas For Wireless Communications, Fei He

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Reconfigurable patch antennas have drawn a lot of research interest for future wireless communication systems due to their ability to adapt to changes of environmental conditions or system requirements. The features of reconfigurable patch antennas, such as enhanced bandwidths, operating frequencies, polarizations, radiation patterns, etc., enables accommodation of multiple wireless services.

The major objective of this study was to design, fabricate and test two kinds of novel reconfigurable antennas: a dual-frequency antenna array with multiple pattern reconfigurabilities, and a pattern and frequency reconfigurable Yagi-Uda patch antenna. Comprehensive parametric studies were carried out to determine how to design these proposed patch …

Mix Design And Mechanical Characterization Of Stabilized Compressed Earth Blocks And Assemblies For The Jemez Pueblo In New Mexico, Nicole B. Trujillo

Civil Engineering ETDs

Earthen structures have a long architectural and cultural heritage in New Mexico. Similar structures are evident around the world. With the current depletion of natural resources and high cost of materials, compressed earth block construction offers a sustainable building material alternative. Stabilized compressed earth blocks (SCEB) are compressed earth blocks with additives such as, hydrated lime or Portland cement to protect the earth block from absorbing water. SCEBs are being produced using native soils for residential construction on the Jemez Pueblo in New Mexico.

The primary goal of this research is to enable production of SCEBs with native soils from …

Unsupervised Feature Selection For Outlier Detection By Modelling Hierarchical Value-Feature Couplings, Guansong Pang, Longbing Cao, Ling Chen, Huan Liu

Research Collection School Of Computing and Information Systems

Proper feature selection for unsupervised outlier detection can improve detection performance but is very challenging due to complex feature interactions, the mixture of relevant features with noisy/redundant features in imbalanced data, and the unavailability of class labels. Little work has been done on this challenge. This paper proposes a novel Coupled Unsupervised Feature Selection framework (CUFS for short) to filter out noisy or redundant features for subsequent outlier detection in categorical data. CUFS quantifies the outlierness (or relevance) of features by learning and integrating both the feature value couplings and feature couplings. Such value-to-feature couplings capture intrinsic data characteristics and …

Orienteering Problem: A Survey Of Recent Variants, Solution Approaches And Applications, Aldy Gunawan, Hoong Chuin Lau, Pieter Vansteenwegen

Research Collection School Of Computing and Information Systems

The Orienteering Problem (OP) has received a lot of attention in the past few decades. The OP is a routing problem in which the goal is to determine a subset of nodes to visit, and in which order, so that the total collected score is maximized and a given time budget is not exceeded. A number of typical variants has been studied, such as the Team OP, the (Team) OP with Time Windows and the Time Dependent OP. Recently, a number of new variants of the OP was introduced, such as the Stochastic OP, the Generalized OP, the Arc OP, …

Doppler Temperature Coefficient Calculations Using Adjoint-Weighted Tallies And Continuous-Energy Cross Sections In Mcnp6, Matthew A. Gonzales

Nuclear Engineering ETDs

The calculation of the thermal neutron Doppler temperature reactivity feedback co- efficient, a key parameter in the design and safe operation of advanced reactors, using first order perturbation theory in continuous energy Monte Carlo codes is challenging as the continuous energy adjoint flux is not readily available. Traditional approaches of obtaining the adjoint flux attempt to invert the random walk process as well as require data corresponding to all temperatures and their respective tem- perature derivatives within the system in order to accurately calculate the Doppler temperature feedback.

A new method has been developed using adjoint-weighted tallies and On-The-Fly (OTF) …

Nanoscale Solutions To Tailor Fiber Architectures For Realizing Composites With Triumvirate Properties, Vishnu Priya Ramineni

All Theses

The paramount need for the development of multifunctional, smart and adaptive material systems for application in industries like automobile, aeronautical and aerospace is undeniable. Polymer composites are fast becoming the primary material options to this demand in light of their superior mechanical properties, low density, high corrosion resistance and easy manufacturability. The design flexibility offered in terms of achieving higher specific properties and light weighting is the key reason behind their success. Among all the properties that composites possess, it is the stiffness, strength and toughness that most applications mandate. These properties however, provide complimentary and contrasting characteristics for composites …

An Experimental And Computational Investigation Of The Mechanical, Structural, And Hydrothermal Properties Of Mesoporous Materials, Dayton Gage Kizzire

Graduate Theses/Dissertations

Periodic mesoporous materials have tunable pore sizes and high surface to volume ratios. Some of the most anticipated applications are those that call for energy harvesting in extreme environments, and these materials have a great structural stability to withstand the harsh conditions. In this work, the structural properties of mesoporous materials SBA-15 silica and Al-SBA-15 aluminosilica have been investigated by pressure dependent in situ small angle x-ray scattering (SAXS) using a diamond anvil cell (DAC) up to ~12 GPa in pressure. Hydrothermal measurements were also made in this manner to near supercritical water/steam conditions (to 255 °C and ~ 114 …

Consumer Perceptions About Pilot Training: An Emotional Response., Timothy G. Rosser

Theses and Dissertations

Civilian pilot training has followed a traditional path for several decades. With a potential pilot shortage approaching, ICAO proposed a new paradigm in pilot training methodology called the Multi-Crew Pilot License. This new methodology puts a pilot in the cockpit of an airliner with significantly less flight time experience than the traditional methodology. The purpose of this study was to determine to what extent gender, country of origin and pilot training methodology effect an aviation consumer’s willingness to fly. Additionally, this study attempted to determine what emotions mediate a consumer’s decision. This study surveyed participants from India and the United …

Modeling And Analysis Of A Novel Imbedded Organic Thermal Cycle, Joel Maker Faure

Theses and Dissertations

A thermal cycle is a device that converts thermal energy into work energy. There is a strong need in the United States and the world for a cycle that can have viable performances with low-grade temperature heat sources to increase the supply of power generation. There are many cycles with different configurations, however most do not involve mixing. Generally speaking this is due to modeling difficulties with multiple constituents, phases, and the technology available that lose performance under these mixed conditions. The gap in technology for mixed flow and phase components is getting smaller due to the need. Current cycles …

Cooling Performance Of Reciprocating Aircraft Engines: A Quantitative Analysis Of 14 Cfr Part 23 Certification Requirements, Kevin Andrew Stuth

Theses and Dissertations

An analysis of the Federal Aviation Administration (FAA) aircraft certification requirements has revealed a potential error in the temperature correction formula the FAA requires aircraft manufacturers to use to process engine cooling performance data for compliance with Part 23 of Title 14 of the Code of Federal Regulations (14 CFR Part 23). The FAA engine cooling performance temperature correction formula, which predicts the critical temperature of engine components, was quantitatively evaluated using data acquired with a single-engine aircraft powered by a normally-aspirated, air-cooled, reciprocating engine. Previous research has failed to analyze the effect ambient air temperature has on oil temperature …

Multiscale Mechanics Of Bone: Examining The Influence Of Genetic Alterations, Brendyn James Miller

Theses and Dissertations

This MSc thesis investigates how genetic alterations involved in the synthesis of proteins or in the regulation of tissue remodeling affects the composition, structure and mechanics of bone at the multiscale levels. This was accomplished by performing two mouse model studies. In the first study, bone properties of TIMP-3 knock-out (Timp-3⁻ˊ⁻) mice were examined by performing mechanical testing, µCT analysis, and FTIR analysis. Results demonstrated that the mechanical integrity of the Timp-3⁻ˊ⁻ bone was compromised. Decreased values for the yield and ultimate load, stress capacity, and fracture toughness were observed in both the TIMP-3 deficient bones. These reductions in the …

A Novel Supercell-Based Dielectric Grating Dual-Beam Leaky-Wave Antenna For 60-Ghz Applications, Zi Long Ma, Kung Bo Ng, Chi Hou Chan, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This communication proposes a novel dual-beam dielectric grating antenna based on the supercell (SC) concept. Through the theoretical analysis of the effective phase constants of the SC, it is found that two space harmonic modes (m=-1 and m=-2) can be simultaneously excited (above the air line) within a certain frequency range. This phenomenon leads to the generation of two radiation beams in the far-field region. At the frequency where the phase constants satisfy β-1=-β-2, the two beams are in symmetric directions with respect to the axis that is perpendicular to the azimuth plane. Different from the conventional periodic structures that …

Evaluation Of User Perceived Qoe In Mobile Systems Using Social Media Analytics, Ahmed Yaseen Mjhool

Theses and Dissertations

In mobile system environments, the quality perceived by users is inconstant and reliant on many factors such as cellular network, data connection, cost, coverage area, etc. Even though Quality of Service (QoS) management is enabled in most modern telecommunication systems, it does not guarantee the actual user’s perceived Quality of Experience (QoE) level. Many cellular networks rely on engineering test research, such as drive testing or smart mobile applications, to collect the required parameters in order to provide better service quality to users. However, this approach does not always yield customer satisfaction. Hence, user opinions should be considered. These opinions …

Time Series Classification Using Covariance Descriptors, Oluwaseun Winsala

Theses and Dissertations

This thesis presents a novel framework for time series classification that leverages the geometric structure of covariance matrices when labeling signals. Our method maps each signal to a new multivariate localized feature signal (MLFS) representation, from which we compute a covariance descriptor. This robust MLFS covarieance representation handles classification tasks where the sampling rates of the signals vary within a class or classes. We demonstrate that by simply using the k-nearest neighbor classification rule and multiclass kernel support vector machine with the Riemannian metric between the MLFS convariance matrices, which produces state-of-the-art results on a number of standard datasets. Moreover, …

Design Of A Rotating Brush Underwater Grooming Device With A Focus On Brush Optimization, Motor Control And Design For Reliability, Mark Harrison Nanney

Theses and Dissertations

The design and control of Remotely Operated Vehicles (ROV) to groom or clean the underwater surface of ship hulls is becoming an important aspect of the maintenance of vessels to the United States Navy. The biological growth below the waterline of the vessels can be the cause for drag penalties near 21% causing up to 32% increase in shaft power at 15 knots (Schultz, 2007). Research conducted by the Center for Corrosion and Biofouling Control at Florida Institute of Technology (FIT) indicated that weekly grooming can prevent high profile biological growth (Hearin, et al., 2015). The design of a rotating …

Maintenance And Improvement Of The Florida Public Hurricane Loss Model, Nicholas Wayne Miller

Theses and Dissertations

The Florida Public Hurricane Loss Model (FPHLM) predicts insurance losses due to hurricane events. This thesis describes maintenance tasks of the vulnerability component of the FPHLM. First, it explores the applicability of recent experimental research to the FPHLM opening protection, water intrusion, and roof pressure modeling features of the Personal Residential (PR) and Commercial Residential Low-Rise (CR-LR.) models. These changes were not implemented because either more experimental data is needed or they had no impact on the losses. Next, it discusses an additional update to the CR-LR model that changed the soffit area calculations, sampling bounds within the rain model, …

Building Exposure Study In The State Of Florida And Application To The Florida Public Hurricane Loss Model, Joshua Michalski

Theses and Dissertations

Modeling hurricane events with models such as the Florida Public Hurricane Loss Model (FPHLM) is essential for insurance and reinsurance companies to estimate projected losses. Additionally, the models can be used by public officials to estimate and mitigate damages while also developing public safety policies to reduce the amount of damage and loss of life during a catastrophic event. The FPHLM combines hurricane event simulation and building vulnerability models to predict insurance portfolios losses. Before vulnerability functions are applied to insurance portfolios to determine total losses, these functions are weighted based upon building characteristics statistics representative of a given building …

A Study To Develop An Electronics Chassis Compound Cylinder Pressure Vessel Using Finite Element Modeling, Gordon Randall Straley

Theses and Dissertations

This thesis develops a process to design and analyze a two-layer compound cylinder pressure vessel utilizing an inner insert to house electronic circuit card assemblies. The process begins with sizing and analysis of a compound cylinder based on analytical formulas and progresses in complexity to a 2-Dimensional plane stress finite element model of the chassis assembly and ends with a computationally expensive 3-Dimensional finite element analysis of the pressure vessel. Comparing the results from the compound cylinder to the electronics chassis, it is observed that the inner insert geometry has a strong influence on the interfacial pressure at the upper …

An Improved Fuel Spray Breakup Model For Advanced Internal Combustion Engine Configurations, Chitra Sadanandan

Theses and Dissertations

Lack of oil resources and increasing effects of global warming have emphasized and led to stricter regulation standards. To meet the current demands, the engines need to be highly efficient in terms of fuel efficiency and performance. One of the fundamental ways to achieve this goal is by studying the fuel atomization and the combustion process. However, there are several challenges involved in studying the process of atomization and combustion only through experimental approaches as they involve numerous parameters. A suitable supplement or alternative to the experimental approach is the numerical approach. Advances in high performance computing, have led to …

The Design Of An Articulating Five-Headed In-Water Grooming Tool To Maintain Ships Free Of Fouling, Caglar Erdogan

Theses and Dissertations

Biofouling is a major concern to ship owners. Biofouling increases hull roughness, increasing the frictional resistance and fuel consumption while decreasing maximum speed. Finding a way to maintain hulls free from fouling has, therefore, become a research challenge for scientists and engineers. Grooming has been proposed as a novel method for controlling fouling (Tribou and Swain 2010). It refers to the regular proactive light cleaning to maintain the hull free of fouling with minimal impact to ship coatings. The purpose of this thesis is to design, build, and deploy a compliant multiheaded grooming tool which utilized five polypropylene vertically rotating …

Synchronization And Random Triggering Of Lymphatic Vessel Contractions, James W. Baish, Christian Kunert, Timothy P. Padera, Lance L. Munn

Faculty Journal Articles

The lymphatic system is responsible for transporting interstitial fluid back to the bloodstream, but unlike the cardiovascular system, lacks a centralized pump-the heart–to drive flow. Instead, each collecting lymphatic vessel can individually contract and dilate producing unidirectional flow enforced by intraluminal check valves. Due to the large number and spatial distribution of such pumps, high-level coordination would be unwieldy. This leads to the question of how each segment of lymphatic vessel responds to local signals that can contribute to the coordination of pumping on a network basis. Beginning with elementary fluid mechanics and known cellular behaviors, we show that two …

Model Building And Security Analysis Of Puf-Based Authentication, Wenjie Che

Electrical and Computer Engineering ETDs

In the context of hardware systems, authentication refers to the process of confirming the identity and authenticity of chip, board and system components such as RFID tags, smart cards and remote sensors. The ability of physical unclonable functions (PUF) to provide bitstrings unique to each component can be leveraged as an authentication mechanism to detect tamper, impersonation and substitution of such components. However, authentication requires a strong PUF, i.e., one capable of producing a large, unique set of bits per device, and, unlike secret key generation for encryption, has additional challenges that relate to machine learning attacks, protocol attacks and …

Structure-Property Relationships Of Polyisobutylene-Block-Polyamide Thermoplastic Elastomers, Morgan Dunn Heskett

Master's Theses

Thermoplastic elastomers (TPEs) are a class of polymer fit for a wide variety of applications due to their customizability. In the synthesis of these types of materials, an elastically-performing polymer, deemed the “soft block,” is combined with a stiffer “hard block” polymer, each of which can be selected based on their own specific properties in order to achieve desired material behavior in the final copolymer. Recently, the use of polyisobutylene as a soft block in combination with a polyamide hard block has been investigated for use in TPE synthesis. While the material showed some promising behavior, many properties were still …

Investigation Of Polymer–Plasticizer Blends As Sh-Saw Sensor Coatings For Detection Of Benzene In Water With High Sensitivity And Long-Term Stability, Pintu Adhikari, Laura Jeanne Alderson, Florian Bender, Antonio J. Ricco, Fabien Josse

Electrical and Computer Engineering Faculty Research and Publications

We report the first-ever direct detection of benzene in water at concentrations below 100 ppb (parts per billion) using acoustic wave (specifically, shear-horizontal surface acoustic wave, SH-SAW) sensors with plasticized polymer coatings. Two polymers and two plasticizers were studied as materials for sensor coatings. For each polymer–plasticizer combination, the influence of the mixing ratio of the blend on the sensitivity to benzene was measured and compared to commercially available polymers that were used for BTEX (benzene, toluene, ethylbenzene, and xylene) detection in previous work. After optimizing the coating parameters, the highest sensitivity and lowest detection limit for benzene were found …

Plasma Processes And Polymers Third Special Issue On Plasma And Cancer, Mounir Laroussi, Annemie Bogaerts, Nazir Barekzi

Electrical & Computer Engineering Faculty Publications

(First paragraph) This issue of Plasma Processes and Polymers is the third in a series on the applications of low temperature plasma (LTP) against cancer, or “plasma oncology.” The papers in this issue are inspired from the talks given at the third International Workshop on Plasma for Cancer Treatment (IWPCT) which took place on April 11–12, 2016 in Washington, DC, USA. IWPCT is an international workshop that was created in 2014 as a venue to share cutting edge plasma oncology research. The first IWPCT was held in Washington DC, under the co-chairmanship of Prof. Mounir Laroussi (Old Dominion University) and …

Development Of A Fundamental Autonomous Ground Vehicle Cruise Control Using Matlab And Simulink, Luis F. Martinez

Theses and Dissertations

This study presents and describes the development of a fully autonomous vehicle cruise control system covering the vehicle dynamics and control design needed to simulate such system. It encompasses obstacle avoidance, intelligent-and-optimal lane change as well as adaptive behavior. This study offers a comprehensive two-dimensional cruise control with three degrees of freedom and it is designed using active obstacle avoidance controllers. It also includes optimized fuzzy logic for optimal vehicle trajectory and an extensive array of control law methodology. The end work shows a complete simulation run using MATLAB and Simulink.

Adaptive Background Modeling With Temporal Feature Update For Dynamic Foreground Object Removal, Li Yin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis explores several approaches in order to develop an effective algorithm for separating the moving objects from the background so that the background alone may be displayed in a video sequence. In particular, this thesis seeks to develop an algorithm that can successfully remove a moving teacher from the whiteboard, so that the writing on the whiteboard may be fully visible to the audience.

In this thesis, some prior works related to this problem are studied to understand the basic principles of adaptive background modeling, or removing the foreground from a background with occasional changes in a video sequence. …

Investigating And Improving Bridge Management System Methodologies Under Uncertainty, Minwoo Chang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation presents a novel procedure to select explanatory variables, without the influence of human bias, for deterioration model development using National Bridge Inventory (NBI) data. Using NBI information, including geometric data and climate information, candidate explanatory variables can be converted into normalized numeric values and analyzed prior to the development of deterministic or stochastic deterioration models. The prevailing approach for explanatory variable selection is to use expert opinion solicited from experienced engineers. This may introduce human influenced biases into the deterioration modeling process. A framework using Least Absolute Shrinkage and Selection Operator (LASSO) penalized regression and covariance analysis are …

Best Practices For Volume Flow Rate Measurements Using Piv At The Exit Of A Turbulent Planar Jet, Rick Cressall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle image velocimetry (PIV) is used to make volume-flow-rate measurements at the exit of a turbulent, planar nozzle. The objective of this report is to assess a range of data acquisition and processing parameters. Data is acquired for volume flow rates of Reynolds numbers between 10,000 and 100,000 for both two-component (2C) and stereo PIV. The parameters are systematically changed one at a time and evaluated using differences in uncertainty, calculation time, and volume- flow-rate deviation. Data acquisition parameters follow the trends of previous work. A multitude of processing parameters were varied for several PIV processing methods. Recommendations for each …

Sensor Placement With Time-To-Detection Guarantees, Saif Eddin Jabari, Laura Wynter

Research Collection School Of Computing and Information Systems

We present a novel and effective method for determining the placement of sensors so as to be able to satisfy probabilistic constraints on the time-to-detection of an incident. Indeed, with the wealth of real-time traffic data available today, an important new goal of intelligent traffic management systems is incident detection with time-to-detection guarantees, in particular on expressways with large distances between sensors. This goal drives investment decisions in new sensor deployment, hence making the topic a pressing need for traffic management. The method we provide makes use of a probabilistic formulation of traffic behavior and incident localization to determine the …