Engineering Commons^™

Activity Analysis Of Spectator Performer Videos Using Motion Trajectories, Anish Timsina

School of Computing: Dissertations, Theses, and Student Research

Spectator Performer Space (SPS) is a frequently occurring crowd dynamics, composed of one or more central performers, and a peripheral crowd of spectators. Analysis of videos in this space is often complicated due to occlusion and high density of people. Although there are many video analysis approaches, they are targeted for individual actors or low-density crowd and hence are not suitable for SPS videos. In this work, we present two trajectory-based features: Histogram of Trajectories (HoT) and Histogram of Trajectory Clusters (HoTC) to analyze SPS videos. HoT is calculated from the distribution of length and orientation of motion trajectories in …

Improving The Efficiency Of Ci With Uber-Commits, Matias Waterloo

School of Computing: Dissertations, Theses, and Student Research

Continuous Integration (CI) is a software engineering practice where developers break their coding tasks into small changes that can be integrated with the shared code repository on a frequent basis. The primary objectives of CI are to avoid integration problems caused by large change sets and to provide prompt developer feedback so that if a problem is detected, it can be easily and quickly resolved. In this thesis, we argue that while keeping changes small and integrating often is a wise approach for developers, the CI server may be more efficient operating on a different scale. In our approach, the …

Design Procedures Of Retrofitted Bridge Rail, Richard L. Wood, Yijun Liao, Mohammad E. Mohammadi, Jordan Wipf

Nebraska Department of Transportation: Research Reports

The use of shallow embedment anchors in concrete is essential for retrofit applications; however, the combination of steel anchors, chemical adhesive, and concrete acting as a single tensile mechanism creates uncertainties in anchor strength and failure modes. Differences in concrete compressive strengths and in specifications of adhesives between manufacturers increases uncertainty further. In addition to these issues, prior research conducted by others examines the behavior of such anchors with respect to cracked versus uncracked concrete, partial bonding of the embedded length, and strength reductions due to anchor proximity to edges. While it is understood, anchors require a proper installation detail, …

Identifying And Addressing Soil Property Issues Affecting Roadside Vegetation Establishment, Xu Li, Martha Mamo, Walter H. Schacht, Tala Awada, Humberto Blanco-Canqui

Nebraska Department of Transportation: Research Reports

Attaining adequate vegetation cover along highways is important for NDOR to comply with EPA’s stormwater regulations. However, low plant cover is a common problem on shoulders (first 16 feet off the pavement) of many highways in Nebraska. The ultimate goal of this study is to identify cost-effective engineering solutions that assure adequate seed beds (i.e., soil conditions) for establishment of selected seeding mixtures. The objectives of this study are to (1) characterize the soil properties along roadsides where vegetation stands have not developed well, and (2) verify the effects of select soil property parameters on plant germination and establishment.

Sampling …

Exploring Dynamic Memory Allocations For Bioinformatics Applications, Nitya Kovur

School of Computing: Dissertations, Theses, and Student Research

The progression of scientific data leads to an increase in the demand of powerful high performance computers (HPC) where data can be stored and analyzed. High performance computing is used in several research areas to solve large problems. However, efficient usage of supercomputing resources that are available is a major concern for most of the researchers. The user has to choose the amount of resources needed for execution before submitting the job. Over or under subscription of resources leads to low system utilization and/or low user satisfaction.

Bioinformatics is one such field that heavily relies on HPC. One of the …

Eventflowslicer: A Goal-Based Test Case Generation Strategy For Graphical User Interfaces, Jonathan Saddler

School of Computing: Dissertations, Theses, and Student Research

Automated test generation techniques for graphical user interfaces include model-based approaches that generate tests from a graph or state machine model of the interface, capture-replay methods that require the user to specify and demonstrate each test case individually, and modeling-language approaches that provide templates for abstract test cases. There has been little work, however, in automated goal-based testing, where the goal is a realistic user task, a function, or an abstract behavior. Recent work in human performance regression testing (HPRT) has shown that there is a need for generating multiple test cases that execute the same user task in different …

Laboratory And Full Boom-Based Investigation Of Nozzle Setup And Restriction Effects On Flow, Pressure And Spray Pattern Distribution, Shane H. Forney

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

Pesticide application is an integral part of crop production and ground-based agricultural boom sprayers are used extensively to apply pesticides to the crop canopy or soil surface across millions of acres in the United States. Efficient application is necessary to minimize costs and limit adverse environmental impacts. Errors in flow rate and system pressure measurements may cause as-applied maps to incorrectly indicate application rates and could negatively affect downstream data processing or analysis. The goals of this study were to provide quantified measurements on the effects of nozzle setup errors on spray pattern uniformity and evaluate how laboratory patternator data …

Design, Testing And Evaluation Of Robotic Mechanisms And Systems For Environmental Monitoring And Interaction, James K. Higgins

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Unmanned Aerial Vehicles (UAVs) have significantly lowered the cost of remote aerial data collection. The next generation of UAVs, however, will transform the way that scientists and practitioners interact with the environment. In this thesis, we address the challenges of flying low over water to collect water samples and temperature data. We also develop a system that allows UAVs to ignite prescribed fires. Specifically, this thesis contributes a new peristaltic pump designed for use on a UAV for collecting water samples from up to 3m depth and capable of pumping over 6m above the water. Next, temperature sensors and their …

Use Of Clustering Techniques For Protein Domain Analysis, Eric Rodene

School of Computing: Dissertations, Theses, and Student Research

Next-generation sequencing has allowed many new protein sequences to be identified. However, this expansion of sequence data limits the ability to determine the structure and function of most of these newly-identified proteins. Inferring the function and relationships between proteins is possible with traditional alignment-based phylogeny. However, this requires at least one shared subsequence. Without such a subsequence, no meaningful alignments between the protein sequences are possible. The entire protein set (or proteome) of an organism contains many unrelated proteins. At this level, the necessary similarity does not occur. Therefore, an alternative method of understanding relationships within diverse sets of proteins …

Unmanned Aerial Vehicles For High-Throughput Phenotyping And Agronomic Research, Yeyin Shi, J. Alex Thomasson, Seth C. Murray, N. Ace Pugh, William L. Rooney, Sanaz Shafian, Nithya Rajan, Gregory Rouze, Cristine L. S. Morgan, Haly L. Neely, Aman Rana, Muthu V. Bagavathiannan, James Henrickson, Ezekiel Bowden, John Valasek, Jeff Olsenholler, Michael P. Bishop, Ryan Sheridan, Eric B. Putman, Sorin Popescu, Travis Burks, Dale Cope, Amir Ibrahim, Billy F. Mccutchen, David D. Baltensperger, Robert V. Avant, Jr., Misty Vidrine, Chenghai Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Advances in automation and data science have led agriculturists to seek real-time, high quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs) have recently gained traction as agricultural …

Alginate Hydrogels As Three-Dimensional Scaffolds For In Vitro Culture Models Of Growth Plate Cartilage Development And Porcine Embryo Elongation, Taylor D. Laughlin

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

The establishment of in vitro culture models utilizes tissue engineering principles to design functional mimics of in vivo environments in vitro. Advantages for the use of in vitro culture models include ethical alleviation of animal models for therapeutic testing, cost efficiency, and a greater ability to study specific mechanisms via a systematic, ground-up approach to development. In this thesis, alginate hydrogels are utilized in the development of in vitro culture models of porcine embryo elongation and growth plate cartilage development. First, the effect of scaffold and modifications to the scaffold were explored in both projects. In order to modulate …

Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil

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

The aim of this research was to evaluate the impact of regional change in ET on groundwater level changes and the assessment and development of a groundwater sustainability index for climatically diverse regions across Nebraska during 2000-2014. Irrigation in the selected regions is predominantly supplied by groundwater. The hypothesis is that groundwater use can become sustainable if the regional evapotranspiration (ET) is managed so that it equals the ET of vegetation that is native to the region. Site locations were Box Butte, Chase, Dundy, Holt LNNRD and York Counties and 3 ecosystems were evaluated: native vegetation, dryland and irrigated cropping …

Control Of Networked Systems With Engineering Applications, Housheng Su, Michael Z.Q. Chen, Qing Hui, Yuan Fan, Zhiwei Gao

Department of Electrical and Computer Engineering: Faculty Publications

Recently, control of networked systems problems has attracted much attention among researchers in biology, physics, control engineering, and computer science for decades, partially due to the broad applications of control of networked systems in many engineering areas including cooperative control of mobile robots and estimation of mobile sensor networks. The study of complex network topology and modeling is to understand the influence of network structure on its function and consequently to find effective ways to improve network performance.

This special issue focuses on theoretical and technological achievements in control of networked systems. The contents of the accepted papers are summarized …

Use Of Recycled Crushed Concrete (Rcc) Fines For Potential Soil Stabilization, Lindeman Mark, Varilek Brandon, Lieska Halsey, Rick Gloe, Maria Olomi

Nebraska Department of Transportation: Research Reports

This study evaluated the use of Recycled Crushed Concrete (RCC) Fines for potential soil stabilization. Soil stabilization is the enhancement of subgrade stability to improve the constructability of successive pavement layers. Use of RCC fines may not only provide less costly alternatives for subgrade stabilization, but their use may also alleviate landfill disposal challenges.

Contribution Of Fiber Undulation To Mechanics Of Three-Dimensional Collagen-I Gel, Shengmao Lin, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The collagen-I gel is extensively used as a scaffold material in tissue engineering due to its ability to mimic the extracellular matrix (ECM). In this study, the mechanics of collagen-I gel is investigated using a numerical model of three-dimensional collagen network. The resulted mechanical behavior was validated against the published experimental data. Results illustrated that fiber alignment was dominated in the low strain region, and its transition to stretching dominated phenomena at higher strain led to the strain stiffening of collagen gel. The collagen undulation at the microscopic level was found to delay the initiation of strain stiffening

On Optimizations Of Virtual Machine Live Storage Migration For The Cloud, Yaodong Yang

School of Computing: Dissertations, Theses, and Student Research

Virtual Machine (VM) live storage migration is widely performed in the data cen- ters of the Cloud, for the purposes of load balance, reliability, availability, hardware maintenance and system upgrade. It entails moving all the state information of the VM being migrated, including memory state, network state and storage state, from one physical server to another within the same data center or across different data centers. To minimize its performance impact, this migration process is required to be transparent to applications running within the migrating VM, meaning that ap- plications will keep running inside the VM as if there were …

Significant Permission Identification For Android Malware Detection, Lichao Sun

School of Computing: Dissertations, Theses, and Student Research

A recent report indicates that a newly developed malicious app for Android is introduced every 11 seconds. To combat this alarming rate of malware creation, we need a scalable malware detection approach that is effective and efficient. In this thesis, we introduce SigPID, a malware detection system based on permission analysis to cope with the rapid increase in the number of Android malware. Instead of analyzing all 135 Android permissions, our approach applies 3-level pruning by mining the permission data to identify only significant permissions that can be effective in distinguishing benign and malicious apps. Based on the identified significant …

The Experiment And Analysis Of Active Mechanisms For Enhancing Heat And Mass Transfer In Sorption Fluids, Ziqi Shen

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

This project was funded by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE RP-1462). It is a three years’ research, including the literature review, labs construction, experiments and data analysis.

In this thesis, first of all, we conducted literature review of mechanism motion influence on heat and mass transfer and additive effect in absorption chiller. This part helps us understand the basic idea of how mechanism motion affects the heat and mass transfer of sorption fluids and gives us reference on how to select the experiment instrument and the experiment operation range.

In the second part, the instrument selection …

Secure And Lightweight Hardware Authentication Using Isolated Physical Unclonable Function, Mehrdad Zaker Shahrak

School of Computing: Dissertations, Theses, and Student Research

As embedded computers become ubiquitous, mobile and more integrated in connectivity, user dependence on integrated circuits (ICs) increases massively for handling security sensitive tasks as well as processing sensitive information. During this process, hardware authentication is important to prevent unauthorized users or devices from gaining access to secret information. An effective method for hardware authentication is by using physical unclonable function (PUF), which is a hardware design that leverages intrinsic unique physical characteristics of an IC, such as propagation delay, for security authentication in real time. However, PUF is vulnerable to modeling attacks, as one can design an algorithm to …

Examining Bridges Between Informal And Formal Learning Environments: A Sequential Mixed Method Design, Dagen L. Valentine

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

The purpose of this sequential mixed method study was to identify schools implementing a technology-based engineering design intervention in a way that connects or bridges formal learning environments of the school-day to informal learning environments such as afterschool programs. Further, this study investigated educators’ decisions that enabled or facilitated bridging between formal and informal learning environments. This cooperation and/or linking between informal and formal learning time is bridging. Participants included public schools (n=16) in Eastern Nebraska that incorporated the Nebraska Wearables Technology (WearTec) program at their school, club or Out-of-School-Time program during the 2015-2016 school year. Three of the schools …

Experimental Modal Analysis And Seismic Mitigation Of Statue-Pedestal Systems, Christine E. Wittich, Tara C. Hutchinson

Department of Civil and Environmental Engineering: Faculty Publications

The seismic protection of cultural heritage, particularly statues, is a critical issue due to its high cultural significance, difficulty to repair or replace artifacts, and observed poor behavior during past earthquakes. Recent research has explored analysis techniques and methodologies for predicting the seismic response of statues; however, these studies typically assume the statue to be either freestanding or rigidly attached. The seismic response of statues with these different boundary conditions varies widely and therefore accurate characterization is critical. While modern mounting techniques aim to rigidly attach a statue to the floor or to a pedestal, the degree of rigidity of …

High-Throughput Screening Of Clinically Approved Drugs That Prime Polyethylenimine Transfection Reveals Modulation Of Mitochondria Dysfunction Response Improves Gene Transfer Efficiencies, Albert Nguyen, Jared P. Beyersdorf, Jean-Jack Riethoven, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nonviral gene delivery methods are advantageous over viral vectors in terms of safety, cost, and flexibility in design and application, but suffer from lower gene transfer efficiency. In addition to modifications to nucleic acid design and nonviral carriers, new tools are sought to enhance transfection. Priming is the pharmacological modulation of transfection efficiency and transgene expression, and has demonstrated transfection increase in several compounds, for example, chloroquine and glucocorticoids. To develop a library of transfection priming compounds, a highthroughput screen was performed of the NIH Clinical Collection (NCC) to identify clinical compounds that prime polyethylenimine (PEI) transfection. HEK293T cells were …

Configuration And Optimization Of A Novel Compressed-Air-Assisted Wind Energy Conversion System, Jie Cheng

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

The increasing concerns over the environmental impact of carbon emissions and the unsustainability of conventional fossil fuel power plants are stimulating interest in the implementation of renewable energy in current power systems. Among all of the renewable energies, wind energy holds a prominent place because of its high output and the maturity of the technology. However, like all of the other renewable energies, integration of wind energy into the power grid causes some quality and control issues, such as overvoltage or undervoltage and frequency excursion.

To mitigate these issues and build a robust wind power system, a novel structure referred …

Cfd Study Of Decay Function Of Wall Shear Stress With Scour Around Complex-Shape Bridge Pier, Chen Li

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Pier scour problem is close related to the safety of bridges. The Federal Highway Administration of the United State also has a great interest in studying the relation between hydraulic loadings and scour depth. The current technological problem of directly measuring hydraulic loadings on a dynamic bed using physical experiments and the weak capacity to simulate the real scour processes with CFD methods inspired the development of a hybrid approach by combining them to study pier scour.

This research specifically focuses on the CFD part of the hybrid method. A series of three-dimensional (3-D) CFD models were developed with unsteady …

Wide Bandgap Organo‐Lead Trihalide Perovskites For Solar Cells, Miao Hu

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Methylammonium lead trihalide perovskite (MAPbX3, where MA is methylammonium, and X is a halide)-based solar cells have been extensively investigated recently, with a demonstrated and certified solar power conversion efficiency (PCE) exceeding 20%. To further boost the PCE beyond the Schockley–Queisser limit, tandem structured solar cells have been investigated based on integrating MAPbX3 and the lower bandgap solar cells. Although the best reported efficiency for this type of tandem cells is not close to the theoretically achievable value, mixed-halide perovskite MAPbBrxI3–x is still one of the most promising candidates as the wide-bandgap light absorber for the tandem application to match …

Effects Of Electrode Off Centre On Trapped Thickness-Shear Modes In Contoured At-Cut Quartz Resonators, Junjie Shi, Cuiying Fan, Minghao Zhao, Jiashi S. Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We investigated thickness-shear vibrations of a contoured, AT-cut quartz resonator with a pair of electrodes displaced from the resonator centre. The scalar differential equations by Stevens and Tiersten for thickness-shear vibrations of electroded and unelectroded quartz plates were employed. Based on the variational formulation of the scalar differential equations established in a previous paper and the variation-based Ritz method with trigonometric functions as basis functions, free vibration resonance frequencies and trapped thickness-shear modes were obtained. The effects of the electrode off centre on resonance frequencies and mode shapes were examined. When the electrode off centre is about one hundredth of …

Class C Fly Ash In Pavements, Kromel E. Hanna, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Modeling Of Soybean Under Present And Future Climates In Mozambique, Manuel António Dina Talacuece, Flávio Barbosa Justino, Rafael De Ávila Rodrigues, Milton Edgar Pereira Flores, Jéssica Garcia Nascimento, Eduardo Eduardo Santos

Daugherty Water for Food Global Institute: Faculty Publications

This study aims to calibrate and validate the generic crop model (CROPGRO-Soybean) and estimate the soybean yield, considering simulations with different sowing times for the current period (1990–2013) and future climate scenario (2014–2030). The database used came from observed data, nine climate models of CORDEX (Coordinated Regional climate Downscaling Experiment)-Africa framework and MERRA (Modern Era Retrospective-Analysis for Research and Applications) reanalysis. The calibration and validation data for the model were acquired in field experiments, carried out in the 2009/2010 and 2010/2011 growing seasons in the experimental area of the International Institute of Tropical Agriculture (IITA) in Angónia, Mozambique. The yield …

An Investigation Of Motor Vehicle Driver Inattention And Its Effects At Highway–Rail Grade Crossings, Shanshan Zhao

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The relationship between accident injury severity and drivers’ inattentive behavior requires an in-depth investigation – this is especially needed in the case of motor vehicle drivers at highway-rail grade crossings (HRGCs). The relationship between drivers’ personality/ socioeconomic characteristics and inattentive behavior at HRGCs is another topic requiring research. Past educational programs about safe driving at HRGCs have often not been designed to target people who may be in urgent need of such information, which may limit the effectiveness of those programs.

This dissertation thus focuses on the following four objectives: to investigate the association between motor vehicle inattentive driving and …

Water And Energy Use Of Antimicrobial Interventions In A Mid-Size Beef Packing Plant, Rami M. M. Ziara, Shaobin Li, Bruce I. Dvorak, Jeyamkondan Subbiah

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Data regarding the water and energy usage of current antimicrobial interventions in beef packing plants is scarce. The objective of this study was to collect representative water and energy usage data in a beef packing plant, with emphasis on antimicrobial interventions, to provide baseline data for comparison of new intervention technologies developed by researchers. Permanent and portable water flow meters were installed on the plant’s plumbing system to collect water flow data from March 2014 to March 2015. A local utility company was hired to meter electricity at the different subsystems using portable data loggers. The natural gas used in …