Engineering Commons^™

A Triangulation Based Coverage Path Planning For A Mobile Robot With Circular Sensing Range, Vatana An

Electronic Theses and Dissertations

In this dissertation, two coverage path planning (CPP) approaches for a nonholonomic mobile robot are proposed. The first approach is the Local Coverage Path Planning (LCPP) approach which is designed for all sensing ranges. The second approach is the Global Coverage Path Planning (GCPP) approach which is designed for sufficient sensing range that can observe all points of interests in the target region (TR). The LCPP approach constructs CP after finding observer points for all local regions in the TR. The GCPP approach computes observer points after CP construction. Beginning with the sample TR, the LCPP approach requires 8 algorithms …

Assessing Interactions Between Estuary Water Quality And Terrestrial Land Cover In Hurricane Events With Multi-Sensor Remote Sensing, Chandan Mostafiz

Electronic Theses and Dissertations

Estuaries are environmentally, ecologically and environmentally important places as they act as a meeting place for land, freshwater and marine ecosystems. They are also called nurseries of the sea as they often provide nesting and feeding habitats for many aquatic plants and animals. These estuaries also withstand the worst of some natural disasters, especially hurricanes. The estuaries as well as the harbored ecosystems undergo significant changes in terms of water quality, vegetation cover etc. and these components are interrelated. When hurricane makes landfall it is necessary to assess the damages as quickly as possible as restoration and recovery processes are …

Ldmos Power Transistor Design And Evaluation Using 2d And 3d Device Simulation, Aiman Salih

Electronic Theses and Dissertations

The benefit of the super-junction (SJ) technique and the use of a floating P layer for low voltage (30 V) laterally double-diffused metal oxide semiconductor (LDMOS) transistors are investigated in this thesis using Sentaurus TCAD simulation software. Optimizations to the SJ LDMOS were attempted such as adding a buffer layer to the device, but simulation and theoretical evidence point out that the benefits of the SJ technique are marginal at the 30 V application. A replacement for the SJ technique was sought, the floating P structure proved to be a good solution at the low voltage range due to its …

An All-Against-One Game Approach For The Multi-Player Pursuit-Evasion Problem, Shahriar Talebi

Electronic Theses and Dissertations

The traditional pursuit-evasion game considers a situation where one pursuer tries to capture an evader, while the evader is trying to escape. A more general formulation of this problem is to consider multiple pursuers trying to capture one evader. This general multi-pursuer one-evader problem can also be used to model a system of systems in which one of the subsystems decides to dissent (evade) from the others while the others (the pursuer subsystems) try to pursue a strategy to prevent it from doing so. An important challenge in analyzing these types of problems is to develop strategies for the pursuers …

Development And Application Of Microelectrodes To Study In Situ Disinfectant Loss And Corrosion On Metal Surface, Xiangmeng Ma

Electronic Theses and Dissertations

The primary objective of this research was to develop, fabricate, evaluate and utilize microelectrodes to metal coupons in artificial water system. In the brass experiment, it presented profiles of direct measurements of free chlorine/monochloramine, oxygen and pH to brass and cement based coupons. In monochloraminated water, brass showed a much faster corrosion process under observation. Profiles showed a less monochloramine consumption with as high as 7% greater oxygen utilization comparing to the brass in free chlorine solution, reflecting oxygen could be a major part of the corrosion initiation process. While cement showed less reactive characteristics to disinfectants and oxygen compared …

Effect Of Load Path And Failure Modes On Seismic Response Of Regular Bridges., Haider Darwash

Electronic Theses and Dissertations

Bridges are essential infrastructure constituents that have been studied for centuries. Typically, seismic bridge design and assessment utilize simplified modeling and analysis techniques based on one-dimensional spine elements and zero-length springs/hinges. The geometry of the elements and calibration of parameters are based on assumptions for the lateral load path and failure modes, e.g., sacrificial backwall and shear keys, neglecting wing walls, and strength based on backfill alone. These assumptions have led to observations of underestimated resistance, overestimated displacement demands, and unpredicted damage and failure mode. The focus of the study is on ordinary standard bridges with continuous reinforced concrete box …

Optimization Approaches For Electricity Generation Expansion Planning Under Uncertainty, Yiduo Zhan

Electronic Theses and Dissertations

In this dissertation, we study the long-term electricity infrastructure investment planning problems in the electrical power system. These long-term capacity expansion planning problems aim at making the most effective and efficient investment decisions on both thermal and wind power generation units. One of our research focuses are uncertainty modeling in these long-term decision-making problems in power systems, because power systems' infrastructures require a large amount of investments, and need to stay in operation for a long time and accommodate many different scenarios in the future. The uncertainties we are addressing in this dissertation mainly include demands, electricity prices, investment and …

A Framework For Measuring Return On Investment For Healthcare Simulation-Based Training, Hatim Bukhari

Electronic Theses and Dissertations

In the healthcare sector, providing high-quality service in a safe environment for both patient and staff is an obvious and ultimate major objective. Training is an essential component for achieving this important objective. Most organizations acknowledge that employee simulation-based training programs are an important part of the human capital strategy, yet few have effectively succeeded in quantifying the real and precise ROI of this type of investment. Therefore, if the training is perceived as a waste of resources and its ROI is not clearly recognized, it will be the first option to cut when the budget cut is needed. The …

Anisotropy Evolution Due To Surface Treatment On 3d-Printed Fused Deposition Modeling (Fdm) Of Acrylonitrile Butadiene Styrene (Abs), Blake E. Lozinski

Honors Undergraduate Theses

Purpose: This paper will present insight to the methodology and results of the experimental characterization of Acrylonitrile Butadiene Styrene (ABS) using Fused Deposition Modeling (FDM). The work in this research explored the effects of print orientation, surface treatment, and ultraviolet (UV) light degradation with the utilization of Digital Image Correlation (DIC) on ABS tensile specimens.

Design/methodology: ABS specimens were printed at three build orientations (flat (0 degrees), 45 degrees, and up-right (90 degrees)). Each of these specimens were treated with three different surface treatments including a control (acrylic paint, Cyanoacrylate, and Diglycidyl Bisphenol A) followed by exposure to UV light …

Improving The Performance Of Data-Intensive Computing On Cloud Platforms, Wei Dai

Electronic Theses and Dissertations

Big Data such as Terabyte and Petabyte datasets are rapidly becoming the new norm for various organizations across a wide range of industries. The widespread data-intensive computing needs have inspired innovations in parallel and distributed computing, which has been the effective way to tackle massive computing workload for decades. One significant example is MapReduce, which is a programming model for expressing distributed computations on huge datasets, and an execution framework for data-intensive computing on commodity clusters as well. Since it was originally proposed by Google, MapReduce has become the most popular technology for data-intensive computing. While Google owns its proprietary …

An Analytical Investigation Of Prestressed Beam Bridge Performance Before And After Widening, Chris Oriordan Adjah

Electronic Theses and Dissertations

As traffic and congestion increase, so does the likelihood of collisions. The solution to this problem is usually through a rehabilitation process with two primary options: (1) widening/expansion of existing roadway and bridges and (2) complete replacement (new construction) of roadway and bridges. The first option is the most feasible and cost-effective. While roadway widening/expansion pose minimal issues, the same cannot be said of bridge widening. An existing bridge presents a multitude of challenges during the planning and design phases, during construction, and throughout the structure's service life. Special attention is required in both the design and detailing of the …

Chaotification As A Means Of Broadband Vibration Energy Harvesting With Piezoelectric Materials, Daniel Geiyer

Electronic Theses and Dissertations

Computing advances and component miniaturization in circuits coupled with stagnating battery technology have fueled growth in the development of high efficiency energy harvesters. Vibration-to-electricity energy harvesting techniques have been investigated extensively for use in sensors embedded in structures or in hard-to-reach locations like turbomachinery, surgical implants, and GPS animal trackers. Piezoelectric materials are commonly used in harvesters as they possess the ability to convert strain energy directly into electrical energy and can work concurrently as actuators for damping applications. The prototypical harvesting system places two piezoelectric patches on both sides of the location of maximum strain on a cantilever beam. …

The Study Of Physiochemical Properties Of Cerium Oxide Nanoparticles And Its Application In Biosensors, Swetha Barkam

Electronic Theses and Dissertations

Biosensors continue to get smaller and faster with the advancement in nanotechnology through the use of nanomaterials to achieve high sensitivity and selectivity. However, the continued reliance on biomolecules or enzymes in the biosensor assembly poses the problem of reproducibility, storage and complexity. This dissertation research address some of the challenges by investigating the physiochemical properties of nanoparticles to understand its interaction with biological systems and develop enzyme free biosensors. In this study, we have demonstrated a novel strategy to integrate cerium oxide nanoparticles (CNPs) as an efficient transducer through rigorous screening for developing enzyme/label free biosensors for detecting analytes …

Investigating Novel Water Treatment Methods And Monitoring Techniques For Sulfide-Laden Groundwater Supplies, Benjamin Yoakum

Electronic Theses and Dissertations

This dissertation reports on research related to novel water treatment and monitoring techniques for sulfide-laden groundwater supplies. The dissertation is divided into several chapters with four core chapters focused on investigations studying a novel water treatment method or monitoring technique. The first investigation assessed the efficacy of multi-pass spray aeration treatment to remove trihalomethanes (THMs) and to reduce the total THM formation potential (TTHMFP) of an aerated water column post-aeration. A recirculating spray aeration pilot unit was constructed to make this assessment. To assess the effect of multi-pass spray aeration on the TTHMFP, water was recirculated through a fabricated spray …

A Training Effectiveness Evaluation Of Uh-60a/L Simulated Environments: An Interdisciplinary Approach, Martin Goodwin

Electronic Theses and Dissertations

The U.S. military continues to develop and expand its use of simulation-based aviation training. While traditional simulation-based training continues to be a proven training method, game-based simulation has become more sophisticated and may provide viable training options in some applications. The use of game-based simulation with traditional simulation-based training can potentially reduce costs, enhance return on investment, advance training objectives, and inform future training environment designs. Current fiscal limitations are driving the need for more efficient training methods, while operational requirements are dictating training protocols that produce optimum levels of readiness. The gap between fiscal constraints and desired training outcomes …

Effects Of Surfactant Concentrations On Perovskite Emitters Embedded In Polystyrene, Eric Calkins

Electronic Theses and Dissertations

With their simple fabrication, narrow light spectrum, and color tunability, a class of materials known as perovskites are emerging as promising candidates for light emission applications. These materials, when exposed to normal atmospheric conditions show significant degradation. Improved protection has been demonstrated by embedding perovskites in polymers. Furthermore, the addition of a surfactant into the precursor solution has been shown to increase stability and allow for color tuning by exploiting quantum confinement effects. However, the effects of surfactants typically used to stabilize perovskites in solution have not been explored in this polymer embedding strategy. Here we determine the physical and …

Weighting Policies For Robust Unsupervised Ensemble Learning, Ramazan Unlu

Electronic Theses and Dissertations

The unsupervised ensemble learning, or consensus clustering, consists of finding the optimal com- bination strategy of individual partitions that is robust in comparison to the selection of an algorithmic clustering pool. Despite its strong properties, this approach assigns the same weight to the contribution of each clustering to the final solution. We propose a weighting policy for this problem that is based on internal clustering quality measures and compare against other modern approaches. Results on publicly available datasets show that weights can significantly improve the accuracy performance while retaining the robust properties. Since the issue of determining an appropriate number …

Spatial And Temporal Compressive Sensing For Vibration-Based Monitoring: Fundamental Studies With Beam Vibrations, Vaahini Ganesan

Electronic Theses and Dissertations

Vibration data from mechanical systems carry important information that is useful for characterization and diagnosis. Standard approaches rely on continually streaming data at a fixed sampling frequency. For applications involving continuous monitoring, such as Structural Health Monitoring (SHM), such approaches result in high data volume and require powering sensors for prolonged duration. Furthermore, adequate spatial resolution, typically involves instrumenting structures with a large array of sensors. This research shows that applying Compressive Sensing (CS) can significantly reduce both the volume of data and number of sensors in vibration monitoring applications. Random sampling and the inherent sparsity of vibration signals in …

A Structural And Functional Analysis Of Human Brain Mri With Attention Deficit Hyperactivity Disorder, Arjun A. Watane

Honors Undergraduate Theses

Attention Deficit Hyperactivity Disorder (ADHD) affects 5-10% of children worldwide. Its effects are mainly behavioral, manifesting in symptoms such as inattention, hyperactivity, and impulsivity. If not monitored and treated, ADHD may adversely affect a child's health, education, and social life. Furthermore, the neurological disorder is currently diagnosed through interviews and opinions of teachers, parents, and physicians. Because this is a subjective method of identifying ADHD, it is easily prone to error and misdiagnosis. Therefore, there is a clear need to develop an objective diagnostic method for ADHD.

The focus of this study is to explore the use of machine language …

Atmospheric Entry, Dillon A. Martin

Honors Undergraduate Theses

The development of atmospheric entry guidance methods is crucial to achieving the requirements for future missions to Mars; however, many missions implement a unique controller which are spacecraft specific. Here we look at the implementation of neural networks as a baseline controller that will work for a variety of different spacecraft. To accomplish this, a simulation is developed and validated with the Apollo controller. A feedforward neural network controller is then analyzed and compared to the Apollo case.

Design Of A Hydrogen-Filled Hollow-Core Fiber Raman Laser, Yangyang Qin

Electronic Theses and Dissertations

The purpose of this study is to investigate the design of a Raman fiber laser based on a molecule hydrogen-filled hollow-core fiber with non-touching single ring of capillaries structure. O-hydrogen vibrational frequency shift of 4155 cm-1 and rotational frequency shift of 587 cm-1 were employed to generate Raman scattering from a 1064nm pump source. A thorough exploration was made to show how all Raman fiber laser components made up: gas chamber, hollow-core fibers, windows. The whole process of chamber design, modification and fabrication were demonstrated. Besides, two kinds of anti-resonant hollow-core fibers were studied and tested. The transmission and loss …

Enhancement Of Bandwidth And Laser Deflection Angle Of Acousto-Optic Deflectors By Dynamic Two-Dimensional Refractive Index Modulation, Tiansi Wang

Electronic Theses and Dissertations

Acousto-Optic Deflectors (AODs) are inertialess optical solid state devices that have advantages over conventional mechanically controlled mirror-based deflectors in numerous scientific and industrial applications. These applications include fluorescence microscopy, sensing, variable-focus lens, photolithography and laser materials processing. AODs are currently operated with a single piezoelectric transducer that modulates the refractive index only in one direction. This operating principle limits the performance of AODs to a narrow acoustic bandwidth of the transducer and a small angle of laser deflection governed by the Bragg diffraction. To overcome these two limitations, the operation of AODs with phased array ultrasonic transducers is analyzed in …

Timoshenko Beam Viscous Damping Model For Spacecraft Cabling Dynamics, Brandi Mcpherson

Electronic Theses and Dissertations

With the increasing data handling and power requirements of today's spacecraft, accurately modeling the effects of cabling on spacecraft structural dynamics has become an increasingly important part of the design process. During testing, spacecraft cabling produces a damping effect on the system dynamics; however, current models often overpredict this response in higher frequency modes and produce unrealistic damping values. Previous models incorporated structural and viscous damping terms into Euler-Bernoulli and shear beams; this thesis presents a viscous damping model for Timoshenko beams that can accurately capture the effects of both spacecraft wiring and harnesses during the design phase. Damping in …

Integrating The Macroscopic And Microscopic Traffic Safety Analysis Using Hierarchical Models, Qing Cai

Electronic Theses and Dissertations

Crash frequency analysis is a crucial tool to investigate traffic safety problems. With the objective of revealing hazardous factors which would affect crash occurrence, crash frequency analysis has been undertaken at the macroscopic and microscopic levels. At the macroscopic level, crashes from a spatial aggregation (such as traffic analysis zone or county) are considered to quantify the impacts of socioeconomic and demographic characteristics, transportation demand and network attributes so as to provide countermeasures from a planning perspective. On the other hand, the microscopic crashes on a segment or intersection are analyzed to identify the influence of geometric design, lighting and …

Signal Processing With Fourier Analysis, Novel Algorithms And Applications, Alam Syed

Electronic Theses and Dissertations

Fourier analysis is the study of the way general functions may be represented or approximated by sums of simpler trigonometric functions, also analogously known as sinusoidal modeling. The original idea of Fourier had a profound impact on mathematical analysis, physics and engineering because it diagonalizes time-invariant convolution operators. In the past signal processing was a topic that stayed almost exclusively in electrical engineering, where only the experts could cancel noise, compress and reconstruct signals. Nowadays it is almost ubiquitous, as everyone now deals with modern digital signals. Medical imaging, wireless communications and power systems of the future will experience more …

Noise, Stability, And Linewidth Performance Of 10-Ghz Optical Frequency Combs Generated From The Nested Cavity Architecture, Kristina Bagnell

Electronic Theses and Dissertations

Optical frequency combs with wide mode spacing and low timing jitter are relied upon for both time domain and frequency domain applications. It has been previously demonstrated that surrounding a low-Q semiconductor laser chip with a long external fiber cavity and inserting a high finesse Fabry–Pérot etalon into this cavity can produce a mode-locked laser with the desired high repetition rate and narrow optical mode linewidths which are of benefit to applications like photonic analog-to-digital conversion and astronomical spectrograph calibration. With this nested cavity architecture, the quality factor of the resonator is effectively determined by the product of the individual …

An Sos Conceptual Model, Lvc Simulation Framework, And A Prototypical Implementation Of Unmanned System Interventions For Nuclear Power Plant Disaster Preparedness, Response, And Mitigation, Matthew Davis

Electronic Theses and Dissertations

Nuclear power plant disasters can have severe and far-reaching consequences, thus emergency managers and first responders from utility owners to the DoD must be prepared to respond to and mitigate effects protecting the public and environment from further damage. Rapidly emerging unmanned systems promise significant improvement in response and mitigation of nuclear disasters. Models and simulations (M&S) may play a significant role in improving readiness and reducing risks through its use in planning, analysis, preparation training, and mitigation rehearsal for a wide spectrum of derivate scenarios. Legacy nuclear reactor M&S lack interoperability between themselves and avatar or agent-based simulations of …

Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik

Electronic Theses and Dissertations

Stadiums, pedestrian bridges, dance floors, and concert halls are distinct from other civil engineering structures due to several challenges in their design and dynamic behavior. These challenges originate from the flexible inherent nature of these structures coupled with human interactions in the form of loading. The investigations in past literature on this topic clearly state that the design of flexible structures can be improved with better load modeling strategies acquired with reliable load quantification, a deeper understanding of structural response, generation of simple and efficient human-structure interaction models and new measurement and assessment criteria for acceptable vibration levels. In contribution …

Understanding Images And Videos Using Context, Gonzalo Vaca Castano

Electronic Theses and Dissertations

In computer vision, context refers to any information that may influence how visual media are understood. Traditionally, researchers have studied the influence of several sources of context in relation to the object detection problem in images. In this dissertation, we present a multifaceted review of the problem of context. Context is analyzed as a source of improvement in the object detection problem, not only in images but also in videos. In the case of images, we also investigate the influence of the semantic context, determined by objects, relationships, locations, and global composition, to achieve a general understanding of the image …

High Dynamic Range Display Systems, Ruidong Zhu

Electronic Theses and Dissertations

High contrast ratio (CR) enables a display system to faithfully reproduce the real objects. However, achieving high contrast, especially high ambient contrast (ACR), is a challenging task. In this dissertation, two display systems with high CR are discussed: high ACR augmented reality (AR) display and high dynamic range (HDR) display. For an AR display, we improved its ACR by incorporating a tunable transmittance liquid crystal (LC) film. The film has high tunable transmittance range, fast response time, and is fail-safe. To reduce the weight and size of a display system, we proposed a functional reflective polarizer, which can also help …