Engineering Commons^™

Effects Of Fabrication Errors On The Focusing Performance Of A Sector Metalens, S. S. Stafeev, A. G. Nalimov, Liam O’Faolain, M. V. Kotlyar

Cappa Publications

Using e-beam lithography, a 16-sector spiral metalens was fabricated in an amorphous silicon, capable of converting linearly polarized incident light into an azimuthally polarized optical vortex. When illuminated by a 633-nm linearly polarized laser beam, the metalens generated a near-surface subwavelength focal spot equal to 0.75 of the incident wavelength at full-width of half-maximum intensity. The focusing performance of the spiral metalens was numerically shown to be sensitive to the deviation of the factual microrelief from the calculated height. For the designed microrelief height, a circularly polarized incident beam was focused into a bright ring with a reverse energy flow …

Analyzing And Modeling Users In Multiple Online Social Platforms, Roy Lee Ka Wei

Dissertations and Theses Collection (Open Access)

This dissertation addresses the empirical analysis on user-generated data from multiple online social platforms (OSPs) and modeling of latent user factors in multiple OSPs setting.

In the first part of this dissertation, we conducted cross-platform empirical studies to better understand user's social and work activities in multiple OSPs. In particular, we proposed new methodologies to analyze users' friendship maintenance and collaborative activities in multiple OSPs. We also apply the proposed methodologies on real-world OSP datasets, and the findings from our empirical studies have provided us with a better understanding on users' social and work activities which are previously not uncovered …

Characterizing Interfacial Bonds In Hybrid Metal Am Structures, John Ross Linn

Theses and Dissertations

The capabilities of various metal Additive Manufacturing (AM) processes, such as Powder Bed Fusion – Laser (PBF-L) and Direct Energy Deposition (DED) are increasing such that it is becoming ever more common to use them in industrial applications. The ability to print atop a substrate broadens that scope of applications. There is ongoing research regarding the mechanical properties of additively processed materials, but little regarding the interaction between additive material and its substrate. An understanding of the mechanical and performance properties of the AM/substrate interface is imperative. This paper describes a study of the strength properties of AM/substrate interfaces, with …

Digital Disruption Solution, Camila Bisinoto Borges, Cristiane Lunardi Das Neves Rodriques, Daniel Dias Landroni, Tatiane De Araugo Mendonça

Graduate Student Works

Since March, 2017, the cost of denied boarding began to draw the attention of all Brazilian airlines because of the Resolution 400 of the Brazilian National Civil Aviation Agency. This Resolution covers several items but here we will focus on the penalty that the airlines need to pay for each passenger who had his boarding denied involuntarily in domestic flights.

An operating restriction of an airline may result in the denial of boarding of a specified number of passengers. When this process of selecting the passengers and their accommodation on another flight happens very close to the time of departure, …

Comprehensive Evaluation Of The Ifloods Radar Rainfall Products For Hydrologic Applications, Bong Chul Seo, Witold F. Krajewski, Felipe Quintero, Mohamed Elsaadani, Radoslaw Goska, Luciana K. Cunha, Brenda Dolan, David B. Wolff, James A. Smith, Steven A. Rutledge, Walter A. Petersen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study describes the generation and testing of a reference rainfall product created from field campaign datasets collected during the NASA Global Precipitation Measurement (GPM) mission Ground Validation Iowa Flood Studies (IFloodS) experiment. The study evaluates ground-based radar rainfall (RR) products acquired during IFloodS in the context of building the reference rainfall product. The purpose of IFloodS was not only to attain a high-quality ground-based reference for the validation of satellite rainfall estimates but also to enhance understanding of flood-related rainfall processes and the predictability of flood forecasting. We assessed the six RR estimates (IFC, Q2, CSU-DP, NWS-DP, Stage IV, …

Gjendja Kufitare E Shfrytëzimit Sipas Ec-2 Plasaritjet Dhe Deformimet, Përparim Neziri

Theses and Dissertations

Në shumë situata të projektimit performanca e pranueshme e strukturave përcaktohet nga kërkesat e shfrytëzueshmërisë. Projektimi sipas shfrytëzueshmërisë në disa aspekte është më i vështirë për t’u kuptuar gjatë projektimit të strukturave të betonit. Kërkesat më të zakonshme që duhet të plotësohen për projektimin sipas Gjendjes Kufitare te Shfrytëzimit janë kufizimi i përkuljes dhe gjerësisë së plasaritjeve sipas kërkesave të kodit në fuqi. Ky material ofron një diskutim të sjelljes strukturore në ngarkesat e shfrytëzueshmërisë dhe metodat e thjeshtuara për kontrollin e perkuljes dhe plasaritjeve që perfshihen në disa nga kodet kryesore të praktikës janë paraqitur, përfshirë Eurokodi 2. Përkulja …

Projektimi Dhe Llogaritja E Konstruksioneve Të Kulmit, Linda Fejzulahi

Theses and Dissertations

Nga koncepti i diplomës lidhur me projektimin dhe llogaritjejn e konstruksionit të kulmit, të projektuar dhe llogaritur janë realizuar këto faza:

Analizat e ngarkesave, ngarkesat e përhershme, ngarkesat e përkohshme, ngarkesat llogaritëse, ngarkesat nga bora, ngarkesat nga era, ndikimet e brendshme, kombinimi ngarkesave, etj.

Projektimi është paraparë të bëhen në periferi të Bujanocit, afer liqenit artficial. Janë projektuar 6 shtëpi malore, tri prej të cilave jane vetëm përdhesë, dhe tri të tjera P+1.

Logistics Best Practices For Regional Food Systems: A Review, Anuj Mittal, Caroline C. Krejci, Teri J. Craven

Industrial, Manufacturing, and Systems Engineering Faculty Publications - Archive

The modern industrial food supply system faces many major environmental and social sustainability challenges. Regional food systems, in which consumers prefer geographically proximate food producers, offer a response to these challenges. However, the costs associated with distributing food from many small-scale producers to consumers have been a major barrier to long-term regional food system success. Logistics best practices from conventional supply chains have the potential to improve the efficiency and effectiveness of regional food supply chains (RFSCs). This paper provides a structured and in-depth review of the existing literature on RFSC logistics, including recommended and implemented best practices. The purpose …

Analysis Of Parkinson's Disease Data, Ram Deepak Gottapu, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

In this paper, we investigate the diagnostic data from patients suffering with Parkinson's disease (PD) and design classification/prediction model to simplify the diagnosis. The main aim of this research is to open possibilities to be able to apply deep learning algorithms to help better understand and diagnose the disease. To our knowledge, the capabilities of deep learning algorithms have not yet been completely utilized in the field of Parkinson's research and we believe that by having an in-depth understanding of data, we can create a platform to apply different algorithms to automate the Parkinson's Disease diagnosis to certain extent. We …

Multi-Objective Evolutionary Neural Network To Predict Graduation Success At The United States Military Academy, Gene Lesinski, Steven Corns

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper presents an evolutionary neural network approach to classify student graduation status based upon selected academic, demographic, and other indicators. A pareto-based, multi-objective evolutionary algorithm utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) fitness evaluation scheme simultaneously evolves connection weights and identifies the neural network topology using network complexity and classification accuracy as objective functions. A combined vector-matrix representation scheme and differential evolution recombination operators are employed. The model is trained, tested, and validated using 5100 student samples with data compiled from admissions records and institutional research databases. The inputs to the evolutionary neural network model are used to classify …

Direct Crystal Formation From Micronized Bone And Lactic Acid: The Writing On The Wall For Calcium-Containing Crystal Pathogenesis In Osteoarthritis?, Anna A. Bulysheva, Nardos Sori, Michael P. Francis

Bioelectrics Publications

Introduction

Pathological calcium-containing crystals accumulating in the joints, synovial fluid, and soft tissues are noted in most elderly patients, yet arthritic crystal formation remains idiopathic. Interestingly, elevated lactic acid and bone erosion are frequently among the comorbidities and clinical features of patients with highest incidence of crystal arthropathies. This work shows that bone particulates (modeling bone erosion) dissolve in lactic acid and directly generate crystals, possibly presenting a mechanism for crystal accumulation in osteoarthritis.

Methods and results

Micronized human bone (average particle size of 160 μm x 79 μm ) completely dissolved in lactic acid in 48 hours, and in …

Emerging Roles Of The Membrane Potential: Action Beyond The Action Potential, Lina Abdul Kadir, Michael Stacey, Richard Barrett-Jolley

Bioelectrics Publications

Whilst the phenomenon of an electrical resting membrane potential (RMP) is a central tenet of biology, it is nearly always discussed as a phenomenon that facilitates the propagation of action potentials in excitable tissue, muscle, and nerve. However, as ion channel research shifts beyond these tissues, it became clear that the RMP is a feature of virtually all cells studied. The RMP is maintained by the cell's compliment of ion channels. Transcriptome sequencing is increasingly revealing that equally rich compliments of ion channels exist in both excitable and non-excitable tissue. In this review, we discuss a range of critical roles …

Two-Level Surrogate-Assisted Differential Evolution Multi-Objective Optimization Of Electric Machines Using 3-D Fea, Narges Taran, Dan M. Ionel, David G. Dorrell

Power and Energy Institute of Kentucky Faculty Publications

A two-level surrogate-assisted optimization algorithm is proposed for electric machine design using 3-D finite-element analysis (FEA). The algorithm achieves the optima with much fewer FEA evaluations than conventional methods. It is composed of interior and exterior levels. The exploration is performed mainly in the interior level, which evaluates hundreds of designs employing affordable kriging models. Then, the most promising designs are evaluated in the exterior loop with expensive 3-D FEA models. The sample pool is constructed in a self-adjustable and dynamic way. A hybrid stopping criterion is used to avoid unnecessary expensive function evaluations.

Optimal Design Of A Switched Reluctance Motor With Magnetically Disconnected Rotor Modules Using A Design Of Experiments Differential Evolution Fea-Based Method, Vandana Rallabandi, Jie Wu, Ping Zhou, David G. Dorrell, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Switched reluctance (SR) machines are attractive because they present relatively high efficiency and torque density in spite of lacking permanent magnets. This paper focuses on a two-objective optimization of an external rotor SR motor with a stator that has concentrated coils and a rotor with magnetically isolated modules. The objectives are minimum loss and mass, and 11 independent dimensionless geometric variables are considered as inputs that affect them. A combined design of experiments (DOE) and differential evolution (DE) approach is proposed. The DOE methodology is used to reduce the search space by eliminating from consideration input variable values, leading to …

Reliability Analysis Of Repairable Systems With Recurrent Misuse-Induced Failures And Normal-Operation Failures, Weiwen Peng, Lijuan Shen, Yan Shen, Qiuzhuang Sun

Research Collection College of Integrative Studies

Failure of a repairable system may be attributed to operators’ misuse or system deterioration. The misuse may further deteriorate the system under normal operating conditions. Motivated by a real-world data set that records the recurrence times of misuse-induced failures and the normal-operation failures, this study proposes a stochastic process model for recurrence data analysis, where one type of failures is affected by the other. A non-homogeneous Poisson process and a trend-renewal process are separately used as the baseline event process models for the misuse-induced failures and the normal-operation failures, respectively. These two models are then combined by treating the event …

Blood Transfusions In Preterm Infants: Changes On Perfusion Index And Intermittent Hypoxemia, Katrina T. Ibonia, Henrietta S. Bada, Philip M. Westgate, Enrique Gomez Pomar, Prasad Bhandary, Abhijit R. Patwardhan, Elie G. Abu Jawdeh

Pediatrics Faculty Publications

BACKGROUND

Red blood cell (RBC) transfusion decreases intermittent hypoxemia (IH) events beyond the first week of life. This benefit may be related to improved perfusion to the respiratory control network. Perfusion index (PI) is a perfusion measure provided by the pulse oximeter. We hypothesized that the benefit in IH after RBC transfusion is associated with an increase in PI. In addition, we assessed the value of PI and clinical measures in predicting the effect of RBC transfusion on IH.

STUDY DESIGN AND METHODS

We prospectively enrolled infants less than 30 weeks' gestation age. PI and oxygen saturation (SpO₂) …

Potential Use Of Dimocarpus Longan Seeds As A Flocculant In Landfill Leachate Treatment, Hamidi Abdul Aziz, Nor Aini Rahim, Siti Fatihah Ramli, Motasem Y.D. Alazaiza, Fatehah Mohd Omar, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

Landfill leachate is a highly polluted and generated from water infiltration through solid waste produced domestically and industrially. In this study, a coagulation-flocculation process using a combination of Polyaluminium chloride (PACl) as a coagulant and Dimocarpus longan seed powder (LSP) as coagulant aid was used in treating landfill leachate. LSP has been tested as the main coagulant and as coagulant aid with PACl. As the main coagulant, the optimum dosage and pH for PACl were 5 g/L and 6, respectively, with removal efficiencies of 67.44%, 99.47%, and 98% for COD, SS, and color, respectively. For LSP as the main coagulant, …

A Discrete Element Method Study Of Granular Self-Organization In An Orbital-Driven Sphere And Computational Fluid Dynamics Simulations Of Slurry Flow In A Single-Loop Loop Reactor, Spencer Blum

Honors Capstones

No abstract provided.

Dscr Based Sensor-Pooling Protocol For Connected Vehicles In Future Smart Cities, Mostafa El-Said, Samah Mansour, Vijay Bhuse

Peer-Reviewed Publications

Smart cities are racing to create a more connected Intelligent Transportation Systems (ITS) that rely on collecting data from every possible sensor such as a smart utility meter or a smart parking meter. The use of more sensors resulted in generating a lot of information that maps the smart city environment conditions to more real time data points that needed to be shared and analyzed among smart city nodes. One possibility, to carry and share the collected data, is in autonomous vehicles systems, which use the Dedicated Short Range Communications (DSRC) technology. For example, in a Car-to-Parking-Meter or a Vehicle-to-Vehicle …

Holistic Approach For Characterizing The Performance Of Wireless Sensor Networks, Amar Yusof Jaffar

Theses and Dissertations

Researchers are actively investigating wireless sensor networks (WSNs) with respect to node design, architecture, networking protocols, and processing algorithms. However, few researchers consider the impact of deployments on the performance of a system. As a result, an appropriate deployment simulator that estimates the performance of WSNs concerning several deployment variables is needed. This research presents a holistic deployment framework that assists decision makers in making optimum WSN deployment choices by considering the terrain of their region of interest and type of deployment. This framework employs empirical propagation models to predict the performance of the deployment in terms of connectivity, coverage, …

Near-Infrared Chiral Plasmonic Metasurface Absorbers, Leixin Ouyang, Wei Wang, Daniel Rosenmann, David A. Czaplewski, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Chirality plays an essential role in the fields of biology, medicine and physics. However, natural materials exhibit very weak chiroptical response. In this paper, near-infrared chiral plasmonic metasurface absorbers are demonstrated to selectively absorb either the left-handed or right-handed circularly polarized light for achieving large circular dichroism (CD) across the wavelength range from 1.3 µm to 1.8 µm. It is shown that the maximum chiral absorption can reach to 0.87 and that the maximum CD in absorption is around 0.70. The current chiral metasurface design is able to achieve strong chiroptical response, which also leads to high thermal CD for …

Modeling Socio-Economic Determinants Of Traffic Fatalities, Amin Azimian, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Over several decades, traffic growth has caused an increased number of traffic crashes, which are associated with economic losses and human sufferings. According to the National Highway Traffic Safety Administration [1] in 2016 there were a total of 34,247 fatal traffic crashes in the United States that resulted into 37,133 fatalities. Risk factors relating to the occurrence of fatal and injury severity of motor vehicle crashes have been extensively studied. Most studies [2-7] that have attempted to model the occurrences of traffic crashes and fatalities have been mainly confined to factors related to driver characteristics, roadway geometry characteristics, traffic characteristics, …

Demonstration Of A Novel 3-D Wind Sensor For Improved Wind Shear Detection For Aviation Operations, Anthony O'Connor

Masters

Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Low level wind shear has been identified as one of the primary factors for aircraft go-arounds and aborted landings. Aviation reports have concluded that pilots need to have improved information in relation to tailwinds, wind shear and wind variations on approach and during the landing phases. The ability for a pilot to land an aircraft safely without the need to go-around or abort a landing due to wind conditions is crucial. During any given year, wind shear occurs thousands of …

Using Low Power 5g Iot Devices Off-Network Utilizing Modified Prose Communication, John Aaron Swarner

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

In setups to enable IoT devices, high power radios are required in each of the devices separately. In order to reduce the power requirements for each individual device, a lower power radio could be used in order to reduce the total power requirements and size for the device and increase battery life or reduce power draws for each device. To enable this, a small change removing the application server requirements would be required. A mesh network could be used to enable communication to the main network, either to a tower that is within the range or through a larger relay …

Supporting Diverse Customers And Prioritized Traffic In Next-Generation Passive Optical Networks, Naureen Hoque

School of Computing: Dissertations, Theses, and Student Research

The already high demand for more bandwidth usage has been growing rapidly. Access network traffic is usually bursty in nature and the present traffic trend is mostly video-dominant. This motivates the need for higher transmission rates in the system. At the same time, the deployment costs and maintenance expenditures have to be reasonable. Therefore, Passive Optical Networks (PON) are considered promising next-generation access technologies. As the existing PON standards are not suitable to support future-PON services and applications, the FSAN (Full Service Access Network) group and the ITU-T (Telecommunication Standardization Sector of the International Telecommunication Union) have worked on developing …

A Comprehensive Framework To Replicate Process-Level Concurrency Faults, Supat Rattanasuksun

School of Computing: Dissertations, Theses, and Student Research

Concurrency faults are one of the most damaging types of faults that can affect the dependability of today’s computer systems. Currently, concurrency faults such as process-level races, order violations, and atomicity violations represent the largest class of faults that has been reported to various Linux bug repositories. Clearly, existing approaches for testing such faults during software development processes are not adequate as these faults escape in-house testing efforts and are discovered during deployment and must be debugged.

The main reason concurrency faults are hard to test is because the conditions that allow these to occur can be difficult to replicate, …

Variable Fidelity Studies In Wake Vortex Evolution, Safety, And Control, Petr Kazarin

Doctoral Dissertations and Master's Theses

The purpose of this research is to develop a variable-fidelity approach for addressing the safety of unmanned aerial system (UAS) operations in the national aerospace system (NAS). This task is implemented on the basis of safety investigation toolkit for analysis and reporting wake vortex safety system (SITAR WVSS) code, which is a dynamic low-fidelity model addressing generation, evolution, and interaction of the leader-aircraft wake vortex with the follower-aircraft lifting surfaces.

The first part of the dissertation deals with the generation, evolution, and interaction of the wake vortices produced by an aircraft. In particular, it presents the results of the vortex …

Direct Adaptive Control For A Trajectory Tracking Uav, Nirmit Prabhakar

Doctoral Dissertations and Master's Theses

This research focuses on the theoretical development and analysis of a direct adaptive control algorithm to enable a fixed-wing UAV to track reference trajectories while in the presence of persistent external disturbances. A typical application of this work is autonomous flight through urban environments, where reference trajectories would be provided by a path planning algorithm and the vehicle would be subjected to significant wind gust disturbances. Full 6-DOF nonlinear and linear UAV simulation models are developed and used to study the performance of the direct adaptive control system for various scenarios. A stability proof is developed to prove convergence of …

A Numerical And Experimental Evaluation Of The Turbulent Heat Flux In A Heated Jet In Crossflow, Michael R. Borghi Jr.

Doctoral Dissertations and Master's Theses

The injection of fully-developed turbulent heated air from a tube into a cooler turbulent duct flow is examined, as an analogy to film cooled turbine blades. Scale Resolving Simulations (SRS) are used to examine the flow numerically. A Detached Eddy Simulation (DES) methodology is examined but found to be ineffective at correctly capturing the physics of the flow. A Large Eddy Simulation (LES) numerical model is developed and applied in which tube and duct turbulence inflow effects are emulated using a divergence-free synthetic eddy method (SEM). The LES sensitivity to the synthetic inflow turbulence is examined with a series of …

Developing Serious Games In Engineering Education: Innovation At The Nexus Of Food, Energy, And Water Systems, Nathan Rice

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

At a time when food, energy, and water (FEW) are of the utmost concern to the security and health of the world, an initiative has begun to understand the interactions between these systems. The goal of Innovation at the Nexus of Food, Energy, and Water Systems (INFEWS) is to bring together research fields that typically work in their own silos to solve complex problems increasing the resiliency and sustainability of the FEW system. Stemming from this initiative was a project to produce an educational immersive simulation game to teach youth about how their food is produced, systems thinking, and sustainable …