Engineering Commons^™

Artificial Intelligence Approaches For Structural Health Monitoring Of Aerospace Structures, Kimberly A. Cardillo

Theses and Dissertations

Structural health monitoring (SHM) and non-destructive evaluation (NDE) have been a significant research topic to help with damage detection in aerospace structures. SHM and NDE techniques are based on extracting damage sensitive features to determine the criticality of damage and lifetime of a structure. Acoustic emission (AE) signal detection is an important technique in SHM and NDE especially for fatigue crack growth. AE signals for thin aerospace structures consist of ultrasonic guided Lamb waves that propagate through the structure. This thesis focuses on AE signal repeatability, load at which AE signals occur, feature extraction, artificial intelligence and electro-mechanical impedance of …

Volume Frequency Response Method For Determining Mass Transfer Mechanisms Of O2 In Carbon Molecular Sieve 3k172, Olivia Smithson

Theses and Dissertations

Carbon molecular sieves (CMS) have grown more desirable over the years as an adsorbent for industrial separation processes as CMS technology has advanced. CMS is commonly used in nitrogen inerting (i.e, oxygen removal from air), carbon dioxide removal from methane and oxygen purification. However, knowledge of the dynamic behavior of these gases on CMS is needed to design and operate efficient and effective separation processes. For this reason, the mass transfer resistances within the micropore at both low and high frequencies were characterized using frequency response, COMSOL Multiphysics modeling, and MATLAB optimization , because frequency response methods have demonstrated the …

Engaging Farmers And The Agriculture Industry Through The Testing Agricultural Performance Solutions Program, Charles A. Burr, Daran Rudnick, Matt Stockton, Robert Tigner, Krystle Rhoades

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The University of Nebraska–Lincoln Testing Agricultural Performance Solutions (TAPS) program involves use of farm management competitions to increase engagement across producers, industry, and universities.Participants make several management decisions throughout the growing season in a controlled field trial held at the university research station. Results are analyzed, and awards are presented for most profitable farm, most efficient farm, and farm with the greatest grain yield. The TAPS program involves several techniques for facilitating participatory assistance, including two-way communication and transformational learning. It has resulted in participants' questioning their past management decisions and realizing that they need to improve their marketing skills …

Introduction To Special Issue Of Irrigation Science: Improving Irrigation Management Across The Ogallala Aquifer, Usa, Allan A. Andales, Daran Rudnick, José L. Chávez

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Groundwater stored in aquifers is a major source of irrigation water for many agricultural regions that receive insufficient precipitation for crop production. In the U.S.A., the High Plains aquifer (HPA) that underlies parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming supplies irrigation water for agricultural production. The HPA underlies around 450,658 km² (174,000 mi²) of which the Ogallala aquifer is the principal geologic formation underlying 347,059 km² (134,000 mi²) (Gutentag et al. 1984). The Ogallala aquifer is primarily a water table (unconfined) aquifer with saturated thickness ranging from 0 …

A Centralised Multi-Objective Model Predictive Control For Biventricular Assist Devices, Vivian Koh Ci Ai

Student Works (2020-2029)

Heart failure is defined as failure of heart to deliver adequate blood flow rate to support tissue perfusion. Heart failure can be treated by implantation of a left ventricular assist device (LVAD) for left heart failure patients, or a biventricular assist device (BiVAD) for bi-heart failure patients. Since left heart failure predominates right heart failure, all commercial ventricular assist devices are LVADs. Therefore, two LVADs are frequently used as BiVAD for bi-heart failure patients. Clinically, the constant speed (CS) control of BiVAD fails to adapt pump flow rate according to physiological changes, thus putting patients at risk of ventricular suction …

Detection And Estimation Of Inundation And Associated Risks Using Traffic And Monitoring Cameras And Image Processing Under Extreme Flooding Conditions, Suyun Ham Ph.D, Seongjin Noh Ph.D, Dong-Jun Seo Ph.D, Yin Chao Yu, Sangoo Kang

Publications

The main objective of this project is to develop an inundation detection and evaluation framework using images from traffic monitoring cameras and reliable flood monitoring under extreme precipitation conditions. This study presents a comparative assessment of image enhancement and segmentation techniques to automatically identify the flash flooding from the low-resolution images taken by traffic-monitoring cameras. Due to inaccurate equipment in severe weather conditions (e.g., raindrops or light refraction on camera lenses), low-resolution images are subject to noises that degrade the quality of information. De-noising procedures are carried out for the enhancement of images by removing different types of noises. After …

Real-Time Early Detection And Monitoring Of Flooding Using Low-Cost Highly Sensitive Ultrasound Sensing Of Water Level, Suyun Ham Ph.D, Seongjin Noh Ph.D, Dong-Jun Seo Ph.D, Sanggoo Kang, Dafnik Saril Kumar David

Publications

Flooding poses safety hazards to motorists, emergency and maintenance crews and may cause costly damage to transportation infrastructure and its operation. Flash flooding, in particular, causes the most flood-related deaths According to NOAA, in 2017 alone, flash flooding also caused $60.7 billion worth of economic damage. Low-water crossings are among the first places where deaths and significant damages to vehicles occur during flooding. With flash flooding, when a critical corridor is blocked by a high level of water, it affects the safety of the general public. To keep the critical corridors open as long as possible, and to minimize losses …

Abq Streets: Creating Alternative Residential Street Designs, Gregory Rowangould Ph.D, Nick N. Ferenchak Ph.D

Publications

This research evaluates opportunities for retrofitting residential streets with alterative designs with the overall goal of improving their function, reducing their negative impacts and reducing maintenance costs. This is accomplished through three main research tasks. First, we conduct a comprehensive review of the street design literature with a focus on studies that report how alterative or unique designs that are relevant to the residential street context affect travel behavior, traffic flow, safety, crime and environmental impacts. We then survey residential streets in several study neighborhoods to measure typical design features and cross sections. With this information we then evaluate which …

Real-Time Work Zone Traffic Management Via Unmanned Air Vehicles, Charles Malveaux Ph.D, Marcio De Queiroz Ph.D, Xin Li Ph.D, Hany Hassan Ph.D, Zewei He Ph.D

Publications

Highway work zones are prone to traffic accidents when congestion and queues develop. Vehicle queues expand at a rate of 1 mile every 2 minutes. Back-of-queue, rear-end crashes are the most common work zone crash, endangering the safety of motorists, passengers, and construction workers. The dynamic nature of queuing in the proximity of highway work zones necessitates traffic management solutions that can monitor and intervene in real time. Fortunately, recent progress in sensor technology, embedded systems, and wireless communication coupled to lower costs are now enabling the development of real-time, automated, “intelligent” traffic management systems that address this problem. The …

Assessment Of Compatibility Of Mineral Aggregates And Binders Used In Highway Construction And Maintenance Projects, Zahid Hossain Ph.D, Ashraf Elsayed Ph.D, Tandra Bagchi, Sumon Roy

Publications

Stripping and delamination have been deemed as some of the major premature pavement distresses to most state Departments of Transportations (DOTs) and highway agencies including the Arkansas Department of Transportation (ARDOT). It is believed that the poor compatibility between asphalt binders and aggregates is one of the major reasons behind this. This study aims to analyze the compatibility of selected asphalt binders and aggregates used in Arkansas. Asphalt binders used in this study include PG 64-22, PG 70-22, and PG 76-22; each prepared from two different crude courses. Additionally, four different types of aggregates (sandstone, limestone, gravel, and dolomite) from …

Impact Of Arsenic Species On Self-Assembly Of Triangular And Hexagonal Tensile-Strained Gaas(111)A Quantum Dots, Christopher F. Schuck, Kevin D. Vallejo, Trent Garrett, Qing Yuan, Ying Wang, Baolai Liang, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

We use dimeric arsenic (As₂) or tetrameric arsenic (As₄) during molecular beam epitaxy to manipulate the structural and optical properties of GaAs(111)A tensile-strained quantum dots (TSQDs). Choice of arsenic species affects nucleation and growth behavior during TSQD self-assembly. Previously, epitaxial GaAs(111)A TSQDs have been grown with As₄, producing TSQDs with a triangular base, and 'A-step' edges perpendicular to the three 1̅1̅2 directions. We demonstrate that using As₂ at low substrate temperature also results in triangular GaAs(111)A TSQDs, but with 'B-step' edges perpendicular to the three 112̅ directions. We can therefore invert the crystallographic …

A Review Of Inkjet Printed Graphene And Carbon Nanotubes Based Gas Sensors, Twinkle Pandhi, Ashita Chandnani, Harish Subbaraman, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Graphene and carbon nanotube (CNT)-based gas/vapor sensors have gained much traction for numerous applications over the last decade due to their excellent sensing performance at ambient conditions. Inkjet printing various forms of graphene (reduced graphene oxide or modified graphene) and CNT (single-wall nanotubes (SWNTs) or multiwall nanotubes (MWNTs)) nanomaterials allows fabrication onto flexible substrates which enable gas sensing applications in flexible electronics. This review focuses on their recent developments and provides an overview of the state-of-the-art in inkjet printing of graphene and CNT based sensors targeting gases, such as NO₂, Cl₂, CO₂, NH_{3 …}

Gaining Insight Into Solar Photovoltaic Power Generation Forecasting Utilizing Explainable Artificial Intelligence Tools, Murat Kuzlu, Umit Cali, Vinayak Sharma, Özgür Güler

Engineering Technology Faculty Publications

Over the last two decades, Artificial Intelligence (AI) approaches have been applied to various applications of the smart grid, such as demand response, predictive maintenance, and load forecasting. However, AI is still considered to be a ‘‘black-box’’ due to its lack of explainability and transparency, especially for something like solar photovoltaic (PV) forecasts that involves many parameters. Explainable Artificial Intelligence (XAI) has become an emerging research field in the smart grid domain since it addresses this gap and helps understand why the AI system made a forecast decision. This article presents several use cases of solar PV energy forecasting using …

Evaluation Of Hyaluronic Acid To Modulate Oral Squamous Cell Carcinoma Growth In Vitro, Jordan Ringer, Bryan Morrison, Karl Kingsley

Dental Medicine Faculty Research

© 2020 MDPI AG. All rights reserved. Introduction: Previous studies have demonstrated that glycosaminoglycan hyaluronic acid (HA) is capable of mediating oral tumor growth. Some clinical evidence has suggested reduced HA expression predicts poor cancer prognosis and that HA-chemotherapy conjugates may function synergistically to inhibit oral tumor growth. Other studies have found conflicting results that suggest enhanced CD44-HA-mediated growth and proliferation. Due to the lack of clarity regarding HA function, the primary goal of this study was to investigate the effects of HA using well-characterized oral cancer cell lines. Methods: Using several commercially available oral squamous cell carcinoma lines (and …

Staying Connected – Interactive Student Learning During The Covid Transition To Remote Learning, Jeffrey A. Starke, Margaret L. Mcnamara, Richard J. Povinelli, Daniela Castillo-Perez, Linda Noelle Brigham

Civil and Environmental Engineering Faculty Research and Publications

Background.

How can we transition courses in one week, while maintaining a similar experience for students? This was probably the initial response by faculty across universities as they transitioned to remote learning, mid-semester, in response to the SARS-CoV-2 pandemic. Our approach is supported by the ICAP framework which posits that “as activities move from passive to active to constructive to interactive, students undergo different knowledge-change processes and, as a result, learning will increase.” (Chi and Wylie, 2014)

Purpose/Hypothesis.

How we could foster students’ interactions with course material, instructors, and their peers using collaborative technology and course activities? It was hypothesized …

Selecting The Most Feasible Construction Phasing Plans For Urban Highway Rehabilitation Projects, Kunhee Choi Ph.D, H. David Jeong Ph.D, Yong-Cheol Lee, Yangtian Yin

Publications

Despite the abundance of research that has aimed to understand the effects of highway work zones, very little definitive information is available concerning the determination of work zone length (WZL). Quantitative studies that holistically model WZL are very rare. To fill this gap, this study identifies critical factors affecting WZL and develops decision support models that determine the optimal WZL in a balanced tradeoff between motorists’ inconvenience due to traffic disruption and their opportunity cost. A high-confidence dataset was created by conducting a series of scheduling and traffic simulations and analyses. The results revealed that traffic loading and work zone …

Seismic Ground Motion Data Analyses For North-East Arkansas, Zahid Hossain Ph.D, Ashraf Elsayed Ph.D, Md Ariful Hasan, Md Rafiue Islam

Publications

Estimation of liquefaction resistance and shear velocities are key elements in the assessment of potential earthquake damage of existing and new construction sites. The Arkansas Department of Transportation (ARDOT) and other agencies in the region need ground motion response analysis (GMRA) data of specific construction sites. As part of a recent ARDOT’s Transportation Research Committee (TRC) project, researchers have conducted geophysical investigations several construction sites in northeast Arkansas over the past twelve years. The current study gathered the previously reported test data and estimated seismic hazard properties such as shear wave velocity profiles and seismic hazard coefficients for nearby locations. …

Enhancing Evaluation Of Wildlife Detection Systems, Nick N. Ferenchak Ph.D

Publications

Every year in the United States, wildlife-vehicle collisions (WVCs) cause 200 human fatalities, 26,000 human injuries, and substantial harm to wildlife populations, resulting in approximately $8.4 billion in total costs. The research team examined two US 64 bridges located near Lumberton, New Mexico that were designed to allow wildlife to cross underneath. Monitoring stations were positioned at each of the crossings so that both wildlife approaches and passages were observed. Special mounting brackets were designed and fabricated to allow for the installation of monitoring equipment. Wildlife observations were supplemented with WVC counts. Over seven months of study, nearly 100,000 wildlife …

Optimizing The Geometric Configuration And Manufacturing Process Of High Mast Illumination Poles, Arturo Montoya Ph.D, Adolfo Matamoros Ph.D, Reza Nasouri, Echizeni Ikpah, Arsalan Majlesi

Publications

This work presents the development of a high-fidelity model that accounts for the cumulative effect of welding and hot- dip galvanizing on the determining the resulting residual stresses and deformations induced during the manufacturing process of high mast illumination poles (HMIPs). This model is meant to elucidate the root causes of weld toe cracks in HMIPs. A TxDOT pole-to-base plate connection detail was used as the reference model in the analysis. Welding was modeled using the plug-in Abaqus Welding Interface (AWI), which automatically implements a series of sequential thermal and mechanical analyses. Then, the welding stress results were used as …

Bridge Construction Monitoring Using Lidar For Quantified, Objective Quality-Control Quality-Assurance (Qoqcqa), Fernando Moreu Ph.D, Chris Lippitt Ph.D, Xinxing Yuan

Publications

Transportation infrastructure construction quality control and quality assurance demands construction monitoring by field inspectors. Currently, these inspectors monitor infrastructure by measuring and photographing structures. These tasks allow them to assess any correction decision during construction or to inform about the quality of the construction process for the future. In order to promote and objective decisions obtained during infrastructure construction, the proposed research project developed and implemented a methodology to measure construction progress and compared it with the designed 3D shape, quantifying the difference. This proposed project includes implementation for the development of DOT standards that could be added in near …

The Impacts Of Increased Adverse Weather Events On Freight Movement, Kyung "Kate" Hyun Ph.D, Stephen P. Mattingly Ph.D, Mehrdad Arabi

Publications

Freight transportation is a major economic backbone of the United States and is vital to sustaining the nation’s economic growth. Ports, as one of the primary components of freight transportation and important means of integrating into the global economic system, have experienced significant growth and increased capacity during the past two decades. The study addresses an important national freight mobility goal to enhance the resilience of the port transportation operations in the event of extreme weather events. This study develops an adaptable resilience assessment framework that evaluates the impact of a disruptive event on transportation operations. The framework identifies dynamic …

Development Of Corrosion Inhibiting Geopolymers Based Cement For Transportation Infrastructure, Homero Castaneda, Miladin Radovic, Changkyu Kim, Oscar Huang

Publications

Geopolymers are gaining attention as affordable, sustainable, and eco-friendly replacement for Ordinary Portland Cement (OPC) in concrete civil structures. More importantly, Geopolymer-based Cement (GPC) provide sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g., fly ash) or abounded natural sources (e.g., clay) and thus reduce significant CO₂ production associated with processing of OPC. Although, a lot of work has been done on improving mechanical properties of GPC over the last two decades, there are only a few studies on effects of GPC concrete on steel rebar …

Eco-Friendly Stabilization Of Sulfate-Rich Expansive Soils Using Geopolymers For Transportation Infrastructure, Xinbao Yu, Anand Puppala, Miladin Radovic, Sayantan Chakraborty, Jungyeon Jang, Oscar Huang

Publications

Traditional calcium-based stabilizers, such as lime, to stabilize sulfate-rich expansive soils, are lasting-challenges in geotechnical engineering. The biggest problem with using calcium-based stabilizers is that when calcium and water are exposed to sulfate-rich expansive soils, they form ettringite as an expansive mineral, which causes sulfate-induced heaving. The study aimed to investigate the feasibility of stabilizing sulfate-rich expansive soils using geopolymers for transportation infrastructure. Literature review on sulfate-induced heaving and sulfate-rich soils stabilized with geopolymers suggests a direction for how to stabilize sulfate soils using geopolymers. The engineering tests were conducted to determine the swell, shrinkage, and strength behavior of natural, …

Advanced Modeling And Design Methodology For Pavements Using Plasticity-Based Shakedown Theory, Shengli Chen, Chao Sun, Xu Wang, Zhiming Zhang

Publications

Pavement design is a process intended to find the most economical combination of layer thickness and material type for the pavement, taking into account the properties of the subgrade soil and the traffic to be carried during the service life of the road. The currently prevalent methods of pavement analysis and design, however, are more or less empirical in U.S., which possess the shortcoming that the important type of pavement distress of rutting related to the accumulation of plastic or permanent deformations cannot be effectively considered. This project proposes an exploratory study on the application of the plasticity theory-based shakedown …

Effect Of Bout Length On Gait Measures In People With And Without Parkinson’S Disease During Daily Life, Vrutangkumar Shah, James Mcnames, Graham Harker, Martina Mancini, Patricia Carlson-Kuhta, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak

Electrical and Computer Engineering Faculty Publications and Presentations

Although the use of wearable technology to characterize gait disorders in daily life is increasing, there is no consensus on which specific gait bout length should be used to characterize gait. Clinical trialists using daily life gait quality as study outcomes need to understand how gait bout length affects the sensitivity and specificity of measures to discriminate pathological gait as well as the reliability of gait measures across gait bout lengths. We investigated whether Parkinson’s disease (PD) affects how gait characteristics change as bout length changes, and how gait bout length affects the reliability and discriminative ability of gait measures …

Deep Reinforcement Learning Approach To Solve Dynamic Vehicle Routing Problem With Stochastic Customers, Waldy Joe, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In real-world urban logistics operations, changes to the routes and tasks occur in response to dynamic events. To ensure customers’ demands are met, planners need to make these changes quickly (sometimes instantaneously). This paper proposes the formulation of a dynamic vehicle routing problem with time windows and both known and stochastic customers as a route-based Markov Decision Process. We propose a solution approach that combines Deep Reinforcement Learning (specifically neural networks-based TemporalDifference learning with experience replay) to approximate the value function and a routing heuristic based on Simulated Annealing, called DRLSA. Our approach enables optimized re-routing decision to be generated …

Online Traffic Signal Control Through Sample-Based Constrained Optimization, Srishti Dhamija, Alolika Gon, Pradeep Varakantham, William Yeoh

Research Collection School Of Computing and Information Systems

Traffic congestion reduces productivity of individuals by increasing time spent in traffic and also increases pollution. To reduce traffic congestion by better handling dynamic traffic patterns, recent work has focused on online traffic signal control. Typically, the objective in traffic signal control is to minimize expected delay over all vehicles given the uncertainty associated with the vehicle turn movements at intersections. In order to ensure responsiveness in decision making, a typical approach is to compute a schedule that minimizes the delay for the expected scenario of vehicle movements instead of minimizing expected delay over the feasible vehicle movement scenarios. Such …

Humans-As-A-Sensor For Buildings — Intensive Longitudinal Indoor Comfort Models, Prageeth Jayathissa, Matias Quintana, Mahmoud Abdelrahman, Clayton Miller

Research Collection College of Integrative Studies

Evaluating and optimising human comfort within the built environment is challenging due to the large number of physiological, psychological and environmental variables that affect occupant comfort preference. Human perception could be helpful to capture these disparate phenomena and interpreting their impact; the challenge is collecting spatially and temporally diverse subjective feedback in a scalable way. This paper presents a methodology to collect intensive longitudinal subjective feedback of comfort-based preference using micro ecological momentary assessments on a smartwatch platform. An experiment with 30 occupants over two weeks produced 4378 field-based surveys for thermal, noise, and acoustic preference. The occupants and the …

The Building Data Genome Project 2, Energy Meter Data From The Ashrae Great Energy Predictor Iii Competition, Clayton Miller, Anjukan Kathirgamanathan, Bianca Picchetti, Pandarasamy Arjunan, Young June Park, Zoltan Nagy, Paul Raftery, W. Brodie Hobson, Zixiao Shi, Forrest Meggers

Research Collection College of Integrative Studies

This paper describes an open data set of 3,053 energy meters from 1,636 non-residential buildings with a range of two full years (2016 and 2017) at an hourly frequency (17,544 measurements per meter resulting in approximately 53.6 million measurements). These meters were collected from 19 sites across North America and Europe, with one or more meters per building measuring whole building electrical, heating and cooling water, steam, and solar energy as well as water and irrigation meters. Part of these data was used in the Great Energy Predictor III (GEPIII) competition hosted by the American Society of Heating, Refrigeration, and …

Finite Element Analysis Investigation Of Hybrid Thin-Ply Composites For Improved Performance Of Aerospace Structures, Alana M. Zahn

Mechanical & Aerospace Engineering Theses & Dissertations

Commercial and private aircraft have a need for strong yet light materials in order to have the most ideal performance possible. This study looks at the use of thin-ply composite materials to improve the performance of aircraft structures by means of weight savings and/or strength increase when compared to laminates that are composed of exclusively standard-ply materials. In order to perform an investigation based solely on finite element analysis, validation efforts were performed using test data from open hole tension, open hole compression, notched tension, and notched compression specimens. Once the models were validated sufficiently, the same modeling practices were …