Engineering Commons^™

Thermal Destratification Of Air Streams To Improve The Cooling Provisioning Of Air-Cooled Data Centers, Anto Joseph Barigala Charles Paulraj

Mechanical and Aerospace Engineering Theses - Archive

Air side economization is an arrangement of duct, damper and automatic control system which together allow introducing outside air to reduce the mechanical cooling during mild or cold weather thereby decrease the energy consumption. The outside ambient air and heated return air from the information technology (IT) pod is mixed inside a dedicated space to achieve a target cold aisle operating temperature and thereby increase economization. Major constrain faced by the design engineers while designing the Mixing Chamber/ Plenum is the stratification of air stream due to the Temperature gradient in the mixed air stream and this stratification can be …

Identification Of The Manageable Construction Rework Indicators And Related Successful Strategies, Piyush Taneja

Civil Engineering Theses - Archive

In construction projects whether small or large scale, in the design and construction phases, contractors and owners face numerous reworks which finally leads to schedule delays and cost overruns. Although studying the causes of the rework has been of interest of many scholars and researchers, they have mainly focused on identifying the entity-based rework indicators. It is pivotal to identify the key project, organizational, and human factors that lead to the rework. Therefore, this study investigated, identified, and prioritized the human, organization, and project-based manageable indicators of rework. In addition, successful strategies which lead to overcoming rework challenges were evaluated. …

Long Term Performance Monitoring Of Shallow Slope Stabilization Utilizing Recycled Plastic Pins, Cory Alan Rauss

Civil Engineering Theses - Archive

Shallow slope failures are prevalent within the North Texas region. As highway slopes are underlain with high plastic clayey soils that experience cyclic shrinking and swelling, the soils shear strength generally decreases as the soil softens, making the soil more susceptible to sloughing and landslides. The Texas Department of Transportation (TxDOT) generally executes a rapid repair method as an economical option for repairing the slope. This method includes the failed soil removal, replacement, and recompaction to rectify the slope surface. While economical initially, this rapid repair technique may potentially prove to be costly with repeated repairs as the method does …

Game-Theoretic Frameworks And Strategies For Defense Against Network Jamming And Collocation Attacks, Ahmed Hemida

Electronic Theses and Dissertations

Modern networks are becoming increasingly more complex, heterogeneous, and densely connected. While more diverse services are enabled to an ever-increasing number of users through ubiquitous networking and pervasive computing, several important challenges have emerged. For example, densely connected networks are prone to higher levels of interference, which makes them more vulnerable to jamming attacks. Also, the utilization of software-based protocols to perform routing, load balancing and power management functions in Software-Defined Networks gives rise to more vulnerabilities that could be exploited by malicious users and adversaries. Moreover, the increased reliance on cloud computing services due to a growing demand for …

A Study Of Nonlinear Dynamics Of Eeg Responses To Simulated Unmanned Vehicle Tasks, Ziqing Xu

Electronic Theses and Dissertations

In the contemporary world, mental workload becomes higher as technology evolves and task demand becomes overwhelming. The operators of a system are usually required to complete tasks with higher complicity within a shorter period of time. Continuous operation under a high level of mental workload can be a major source of risk and human error, thus put the operator in a hazardous working environment. Therefore, it is necessary to monitor and assess mental workload. In this study, an unmanned vehicle operation with visual detection tasks was investigated by means of nonlinear analysis of EEG time series. Nonlinear analysis is considered …

Applications Of Deep Learning Models For Traffic Prediction Problems, Rezaur Rahman

Electronic Theses and Dissertations

Deep learning coupled with existing sensors based multiresolution traffic data and future connected technologies has immense potential to improve traffic operation and management. But to deal with complex transportation problems, we need efficient modeling frameworks for deep learning models. In this study, we propose two different modeling frameworks using Deep Long Short-Term Memory Neural Network (LSTM NN) model to predict future traffic state (speed and signal queue length). In our first problem, we present a modeling framework using deep LSTM NN model to predict traffic speeds in freeways during regular traffic condition as well as under extreme traffic demand, such …

Vibration Reduction Of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning, Garrett Lopp

Electronic Theses and Dissertations

Recent trends in turbomachinery blade technology have led to increased use of monolithically constructed bladed disks (blisks). Although offering a wealth of performance benefits, this construction removes the blade-attachment interface present in the conventional design, thus unintentionally removing a source of friction-based damping needed to counteract large vibrations during resonance passages. This issue is further exacerbated in the presence of blade mistuning that arises from small imperfections from otherwise identical blades and are unavoidable as they originate from manufacturing tolerances and operational wear over the lifespan of the engine. Mistuning is known to induce vibration localization with large vibration amplitudes …

Nanowire Based Adsorbents/Catalysts For Co2 Capture And Utilization., Apolo Nambo

Electronic Theses and Dissertations

Even today, the major energy source is fossil fuels, which release CO₂, a greenhouse gas that contributes to global warming. CO₂ capture, storage (CCS) and/or utilization (CCU) technologies are two routes to mitigate this problem. Sorbents are being investigated in either temperature swing or pressure swing absorption approaches for carbon capture from flue gases. Solid sorbent based technology is a promising one but suffers from slow kinetics, low capacity and need for high temperatures. Thus, new sorbent materials that can have good CO₂ sorption capacity, recyclability are sought. Similarly, one of the utilization approaches for CO …

Plasma-Assisted Liquid Phase Epitaxy Of Gallium Nitride Using Molten Gallium., Daniel Felipe Jaramillo-Cabanzo

Electronic Theses and Dissertations

Next generation semiconductor materials such as Gallium Nitride (GaN) and Silicon Carbide (SiC) are rapidly replacing Silicon (Si) for high power and high frequency applications due to Si’s inherent limitations. Despite the advantages of GaN over SiC, adoption of GaN has been hindered due to the lack of a cost-effective bulk production technique. Thus, the inability to precure native substrates requires GaN-based architectures to be heteroepitaxially synthesized on non-native substrates, such as sapphire and even SiC. This research seeks to develop a cost effective and scalable method to produce low defect, bulk GaN encouraging the adoption of GaN based devices …

Lithium Molybdate-Sulfur Battery., Ruchira Ravinath Dharmasena

Electronic Theses and Dissertations

Rechargeable energy storage systems play a vital role in today’s automobile industry with the emergence of electric vehicles (EVs). In order to meet the targets set by the department of energy (DOE), there is an immediate need of new battery chemistries with higher energy density than the current Li- ion technology. Lithium–sulfur (Li–S) batteries have attracted enormous attention in the energy-storage, due to their high specific energy density of 2600 Wh kg^-1 and operational voltage of 2.0 V. Despite the promising electrochemical characteristics, Li-S batteries suffer from serious technical challenges such as dissolution of polysulfides Li₂S_{x …}

Plasma Oxidation Of Liquid Precursors For Complex Metal Oxides., Babajide Patrick Ajayi

Electronic Theses and Dissertations

Clean energy production and storage are two of the most significant challenges in the 21^st century currently limited by the discovery and development of new and advanced materials. Complex oxides and alloys made using earth-abundant elements will play a crucial role in technology development moving forward, however, current preparation techniques are limited by their inability to produce complex oxides and alloys with precise composition control at fast timescales. A concept was proposed to produce mixed metal oxides with composition control through the oxidation of liquid precursors via plasma oxidation. It was hypothesized that the oxidation process can be completed …

Evaluating The Water Quantity And Quality Performances Of Underground Gravel Filter Basins., Jihad A. Hallany

Electronic Theses and Dissertations

Underground gravel filter basins (UGF basins) are subsurface structures that are used for detention, filtration, and infiltration of stormwater runoff in urbanized areas. The application of these structures is recommended in highly developed urban areas, where land is not available or it is too expensive for surface-level green infrastructures such as stormwater ponds, bio-retention, and infiltration trenches. Objectives of this study are to assess and analyze the effectiveness of two (2) UGF basins in reducing the stormwater runoff peak flow, and to assess water quality parameters in a high-density residential area. The experimental site is located at Red Mile Village, …

An Explainable Sequence-Based Deep Learning Predictor With Applications To Song Recommendation And Text Classification., Khalil Damak

Electronic Theses and Dissertations

Streaming applications are now the predominant tools for listening to music. What makes the success of such software is the availability of songs and especially their ability to provide users with relevant personalized recommendations. State of the art music recommender systems mainly rely on either Matrix factorization-based collaborative filtering approaches or deep learning architectures. Deep learning models usually use metadata for content-based filtering or predict the next user interaction (listening to a song) using a memory-based deep learning structure that learns from temporal sequences of user actions. Despite advances in deep learning models for song recommendation systems, none has taken …

Clustering Heterogeneous Autism Spectrum Disorder Data., Mariem Boujelbene

Electronic Theses and Dissertations

Autism spectrum disorder (ASD) is a developmental disorder that affects communication and behavior. Several studies have been conducted in the past years to develop a better understanding of the disease and therefore a better diagnosis and a better treatment by analyzing diverse data sets consisting of behavioral surveys and tests, phenotype description, and brain imagery. However, data analysis is challenged by the diversity, complexity and heterogeneity of patient cases and by the need for integrating diverse data sets to reach a better understanding of ASD. The aim of our study is to mine homogeneous groups of patients from a heterogeneous …

Development Of A Mechanical Device For Measuring Connection Rotations During Seismic Loading, Garrett Tatum

Civil Engineering Undergraduate Honors Theses

This engineering design project sought to design a cheap and easy-to-use sensor to monitor seismic connection rotations in steel buildings during earthquakes by using a linear ratchet mechanism. The idea for the project goes against the mainstream of research that is seeking to develop complex digital networks for monitoring structures in earthquake regions. Whereas many modern sensor networks require high-cost, professionally maintained digital networks, an analog sensor could provide much of the same information at a fraction of the cost, allowing sensors to be more widely utilized, particularly in developing countries. This project required an iterative engineering design process to …

Probable Maximum Flood Estimation Using A Statistical Approach And A Storm Model Approach For A Watershed In Southern St. Vincent, Khandi Gordon

Civil Engineering Undergraduate Honors Theses

With the increase in frequency and severity of flooding due to natural events, there is an increased need for flood studies in order to mitigate the effects of flooding. Some of the most vulnerable countries to flooding are Small Island Developing States (SIDS). These countries face many common development challenges, including geographic and economic isolation, limited resources, environmental fragility, high costs of transportation and energy, and vulnerability to climate change and natural disasters. This project focuses on estimating the probable maximum flood (PMF) for a watershed in a SIDS. To find PMF, the probable maximum precipitation (PMP) is needed. Two …

3d Printed Smart Mobile, Bingfang Chen

Publications and Research

The goal of this research project is to design and build a prototype of a smart mobile robot to participate and compete in IEEE Micro-mouse and similar competitions. The robot has to find its way out of a maze as quickly as possible, by exploring and learning the paths in the maze. 3D printing technology will be used to build a lightweight robot frame so that it can move at a fast speed.

Vision Sensor Based Action Recognition For Improving Efficiency And Quality Under The Environment Of Industry 4.0, Zipeng Wang, Ruwen Qin, Jihong Yan, Chaozhong Guo

Engineering Management and Systems Engineering Faculty Research & Creative Works

In the environment of industry 4.0, human beings are still an important influencing factor of efficiency and quality which are the core of product life cycle management. Hence, monitoring and analyzing humans' actions are essential. This paper proposes a vision sensor based method to evaluate the accuracy of operators' actions. Each action of operators is recognized in real time by a Convolutional Neural Network (CNN) based classification model in which hierarchical clustering is introduced to minimize the effects of action uncertainty. Warnings are triggered when incorrect actions occur in real time and applications of action analysis of workers on a …

Characterizing Truck Parking Shortages In Arkansas: A Data Analytical Approach, Morgan Hartsell

Industrial Engineering Undergraduate Honors Theses

The Truck Parking Problem occurs when drivers have met the daily driving limit and encounter a decision between driving over time or parking in unauthorized locations. This research applies data analytics to gain further knowledge to characterize the truck parking shortage in Arkansas. Truck parking shortages are a serious problem that truck drivers face daily and is complex due to Hours of Service (HOS) regulations restrictions on legal parking areas and design. Existing research includes a one-day annual survey which compiles where public rest stops, businesses, and private rest stops are utilized by truck drivers. This research expands on the …

Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh

Electronic Theses and Dissertations

Electroencephalography (EEG) non-invasively records electrocortical activity and can be used to understand how the brain functions to control movements and walking. Studies have shown that electrocortical dynamics are coupled with the gait cycle and change when walking at different speeds. Thus, EEG signals likely contain information regarding walking speed that could potentially be used to predict walking speed using just EEG signals recorded during walking. The purpose of this study was to determine whether walking speed could be predicted from EEG recorded as subjects walked on a treadmill with a range of speeds (0.5 m/s, 0.75 m/s, 1.0 m/s, 1.25 …

Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano

Electronic Theses and Dissertations

For this thesis, a study was completed on two different structures on the UCF Orlando campus through the use of both structural plans and point cloud technology. The results sought to understand the viability of point cloud technology as an accurate tool for the static and dynamic modal analysis of existing structures. For static analysis, a portion of the framing of Spectrum Stadium was rendered, modeled, analyzed and compared to a previous case study. The results emphasized how different users can render dissimilar member sizes and lengths due to human judgment on point cloud visuals. The study also found that …

Forward Osmosis For Algae Dewatering And Electrical Field-Driven Membrane Fouling Mitigation, Faris Munshi

Electronic Theses and Dissertations

Efficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was achieved with a 29% flux drop. Among three different DSs, although NH4Cl was the best candidate for improved water flux and low reverse salt flux (RSF), it could accelerate cell division, …

Hybrid Life Cycle Sustainability Assessment-Based Multi-Objective Optimization: A Case For Sustainable Fleet Mix, Burak Sen

Electronic Theses and Dissertations

Sustainable transportation idea includes not only switching from conventional energy sources to alternative fuel resources, but also diverging from private vehicle use and shifting to alternative transportation modes. As a part of alternative transportation mode, utilizing alternative fuels in public transportation operation supports sustainable transportation at it full-glance. Given their implications in terms of air quality and sustainable movement of people, transit buses, which provide the primary public transportation service, are considered an ideal domain for the deployment of alternative fuels. An input-output (IO) model is developed based on Eora database – a detailed IO database that consists of national …

Plane Wave Scattering By A Dielectric Circular Cylinder In The Vicinity Of A Conducting Strip (Tm Case), Hassan Ali Ragheb

Electrical Engineering

Scattering of plane electromagnetic waves by a dielectric circular cylinder in the vicinity of a conducting strip is presented. Two methods of solution are introduced. The first is an exact solution in which the scattered field from conducting strip is expressed in terms of Fourier series of radial and angular Mathieu function of unknown coefficient. Meanwhile the scattered field from the circular cylinder is expressed in terms of Fourier series of Bessel functions of unknown coefficient. The unknown coefficient can be obtained by enforcing the boundary conditions. The application of the boundary condition requires the use of the addition theorem …

A Systems Engineering Approach To Improving The National Weather Service, Joanna Fregoso

LMU Theses and Dissertations

The National Weather Service (NWS) is responsible for ensuring that the U.S is a weather ready nation. The mission of the NWS focuses on protecting the lives and property of those in the U.S, while also enhancing the national economy. The number of high-impact weather events have increased over the past decades, suggesting a need for a more effective NWS. This paper focuses on improving the NWS by following the systems engineering approach and using system architecting principles.

Exploring Perceived Usability And Interpretability Of Aviation Weather Products Among Ga Pilots, Jackie Mcsorley, Jayde King, Beth Blickensderfer

General Aviation Weather Display Interpretation

• Introduction
• Results
• Discussion
• Current Investigations

A Comparison Of Discrete Damage Modeling Methods: The Effect Of Stacking Sequence On Progressive Failure Of The Skin Laminate In A Composite Pi-Joint Subject To Pull-Off Load, Joseph Keith Novak

Mechanical and Aerospace Engineering Theses - Archive

Discrete damage modeling of composite failure mechanisms including delamination, matrix cracking, and their interactions was performed for the skin laminate in a composite pi-joint test specimen subject to a pull-off load. The skin laminate stacking sequence was varied, and the pull-off load and path of predicted damage were recorded. Within the study two discrete damage modeling tools were used, Abaqus XFEM with a LaRC05 built-in user subroutine and BSAM. Both tools implement failure criteria developed at the NASA Langley Research Center (LaRC) to predict the location of damage initiation and both tools use similar cohesive zone models to model damage …

Uav: Trajectory Generation And Simulation, Neha Bhushan

Electrical Engineering Theses - Archive

Unmanned Aerial Vehicles (UAVs) have gained mass popularity in fields such as Defense, Agriculture, Sport and Photography etc. Their wide adoption in such research projects have opened new horizons for opportunities. However, UAVs operate in a rather dynamic environment since various factors such as airspeed, temperature, pressure, turbulence etc. are capable of hampering the flight operation. There is a need for rather robust trajectory generation algorithm and system such that it provides an easy user interface to specify the path of UAV through space, alongside making the UAV capable enough to maneuver itself from the initial to final position. This …

On The Analysis Of On-Board Sensing And Off-Board Sensing Through Wireless Communication For Uav Path Planning In Wind Fields, Murilo Augsto Pinheiro

Electrical Engineering Theses - Archive

This work focuses on the roles of on-board sensing and off-board sensing through wireless communication for UAV missions. Employing UAV path planning under spatiotemporal wind effect as a case study, this work implements a modeling framework composed by the vehicle dynamics, environmental effect and communication model that transmits wind field data. Based on the analysis of the minimum-time optimal UAV path planning solution under communication constraints and spatiotemporal wind impact, this work obtains quantitative insights into the effect of communication quality and information update configuration on the performance of path planning. This study finds that on-board sensing and off-board sensing …

Projekti Ideor I Rrugës Me Numër 7 Në Lagjen Panorama Residence, Erand Tahiri

Theses and Dissertations

Historia e rrugëve dhe zhvillimit të tyre është shumë e gjatë. Pohimi se rrugët e para ishin shtigje të bëra nga kafshët nuk është pranuar në mënyrë universale pasi studiuesit thonë se në shumë raste kafshët nuk ndjekin shtigje e njëjta në mënyre të vazhdueshme. Nëse kthehemi prapa në kohë do të shohim se rrugët e para ishin mjaft të thjeshta dhe mënyra e parë e transportimit të mallrave nga një vend në vendin tjetër ishte në këmbë. Këto rrugë njeriu i kishte zhvilluar për qëllime specifike, si bartja e ushqimit dhe mallrave të ndryshme. Në ndërkohë filluan të përdoreshin …