Engineering Commons^™

Editorial: Innovative Human-Centric Investigations And Technologies For Human Wellbeing And Health In The Built Environment, Francesco Salamone, Giorgia Chinazzo, Clayton Miller, Sergio Sibilio, Massimiliano Masullo

Research Collection College of Integrative Studies

The built environment should be designed and operated to create safe, comfortable, and productive spaces for humans. To achieve this goal, it is necessary to understand human responses to environmental stimuli including, but not limited to, thermal, visual, air, and acoustic quality stimuli. Such an investigation allows researchers to identify threshold values, indexes, and models capturing human responses to environmental stimuli, which in turn can be used to design and control buildings to achieve tailored comfortable, healthy, and productive conditions with a limited energy use. In this context, human-centric approaches are becoming increasingly popular in the scientific community due to …

Limitations Of Machine Learning For Building Energy Prediction: Ashrae Great Energy Predictor Iii Kaggle Competition Error Analysis, Clayton Miller, Bianca Picchetti, Chun Fu, Jovan Pantelic

Research Collection College of Integrative Studies

Research is needed to explore the limitations and potential for improvement of machine learning for building energy prediction. With this aim, the ASHRAE Great Energy Predictor III (GEPIII) Kaggle competition was launched in 2019. This effort was the largest building energy meter machine learning competition of its kind, with 4370 participants who submitted 39,403 predictions. The test dataset included two years of hourly whole building readings from 2380 meters in 1448 buildings at 16 locations. This paper analyzes the various sources and types of residual model error from an aggregation of the competition’s top 50 solutions. This analysis reveals the …

Low-Latency And Fresh Content Provision In Information-Centric Vehicular Networks, Shan Zhang, Junjie Li, Hongbin Luo, Jie Gao, Lian Zhao, Xuemin Sherman Shen

Electrical and Computer Engineering Faculty Research and Publications

In this paper, the content service provision of information-centric vehicular networks (ICVNs) is investigated from the aspect of mobile edge caching, considering the dynamic driving-related context information. To provide up-to-date information with low latency, two schemes are designed for cache update and content delivery at the roadside units (RSUs). The roadside unit centric (RSUC) scheme decouples cache update and content delivery through bandwidth splitting, where the cached content items are updated regularly in a round-robin manner. The request adaptive (ReA) scheme updates the cached content items upon user requests with certain probabilities. The performance of both proposed schemes are analyzed, …

A Study Of Wings With Constant And Variable Sweep For Aerodynamic Efficiency In Inviscid Flow, Bruno Moorthamers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wing sweep has been studied by industry and academia since the pioneering days of aviation for both high-speed and low-speed applications. In transonic and supersonic flight regimes it serves to delay the onset of compressibility effects and decrease wave drag. In subsonic conditions, flying wing designs sweep back the main lifting surface in such a way that it can be used for longitudinal stability and control, to allow for the elimination of a traditional empenage. This is desirable because it can decrease the aerodynamic drag. Sweep can also be seen in nature in the wings of birds and fins of …

Improving Flood Inundation And Streamflow Forecasts In Snowmelt Dominated Regions, Irene Garousi-Nejad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Much effort has been dedicated to expanding hydrological forecasting capabilities and improving understanding of the continental-scale hydrological modeling used to predict future hydrologic conditions and quantify consequences of climate change. In 2016, the National Oceanic and Atmospheric Administration’s (NOAA) Office of Water Prediction implemented the National Water Model (NWM) to provide nationally consistent, operational hydrologic forecasting capability across the continental U.S. The primary goal of this research was to develop hydrological tools that include modeling of flood inundation mapping and snowmelt contributions to river flow in snowmelt-dominated regions across the Western U.S. This dissertation first presents terrain analysis enhancements developed …

Thermodynamic Analysis Of A Novel Cycle For Nuclear Smr And Heat Transfer Performance Validation Of The Related Supercritical Working Fluids, Benjamin M. Pepper

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Currently, all operating nuclear power facilities in the U.S. follow the same general design and process: light-water reactors boil water into steam using bundles of nuclear fuel rods as a heat source, pumping that steam through a turbine which powers a generator to produce clean year-round electricity. Water is an effective coolant, but other facilities around the world have demonstrated the ability to use non-water-based coolants in nuclear reactor designs, which consequently have their own trade-offs. Some positive consequences of using different reactor designs include enhanced safety, better economics, and cheaper clean consumer energy. The work described in this paper …

Evaluating Plant Uptake Of 4,4'-Methylenedianiline, Jeff Wight

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

4,4’-Methylenedianiline (MDA) is an important industrial chemical used primarily in the production of polyurethane. It is toxic and a suspected human carcinogen. Polyurethane is used in a wide variety of applications such as furniture cushioning, coatings, adhesives, sealants, and elastomers. Polyurethane in soil may degrade and release MDA. This is concerning due to some models predicting a high potential for MDA to be taken up by plants and stored in edible tissue, creating a possible route of exposure for humans and animals. In this project, the potential for MDA to be take up by plants was investigated in order to …

Advancing Data Collection, Management, And Analysis For Quantifying Residential Water Use Via Low Cost, Open Source, Smart Metering Infrastructure, Camilo J. Bastidas Pacheco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urbanization, climate change, aging infrastructure, and the cost of delivering water to residential customers make it vital that we achieve a higher efficiency in the management of urban water resources. Understanding how water is used at the household level is vital for this objective.Water meters measure water use for billing purposes, commonly at a monthly, or coarser temporal resolutions. This is insufficient to understand where water is used (i.e., the distribution of water use across different fixtures like toilets, showers, outdoor irrigation), when water is used (i.e., identifying peaks of consumption, instantaneous or at hourly, daily, weekly intervals), the efficiency …

Calibration Procedure For Dic Strain Measurements During Vibration-Based Fatigue Testing, Benjamin D. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vibration-based fatigue testing is fast and effective method for determining failure characteristics of a material. Often, a small electrical device called a strain gage is bonded to a rectangular plate specimen to measure the deformation of the plate during a test. However, these strain gages break before the plate does, so an alternative method would improve the results obtained from the test. As an alternative to strain gages, Digital Image Correlation (DIC) is a non-contacting, camera-based technique that measures the deformation of an object by comparing digital images taken before and after the object is deformed. During a vibration-based fatigue …

Evaluation Of Human And Ecological Water Management Tradeoffs In A Seasonal Watershed With Spatially-Distributed Demands, Jesse Lee Rowles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River managers must balance the needs of the ecosystems that rely on the river by leaving water instream, often while also considering human demands. It is especially difficult to balance these water needs in systems that are highly seasonal and have no instream storage (e.g., reservoirs) since water cannot be stored for use throughout the year. An example of a watershed that has both of these characteristics is the South Fork Eel River in coastal northern California. In order to evaluate tradeoffs between human and ecological demands in this system, a water allocation model with water management scenarios and environmental …

What Keeps Technology And Engineering Teachers In The Classroom? A National Mixed Methods Study, Cory J. Ortiz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Teacher retention is a significant issue impacting educational agencies around the country. Factors that have been found to be predictors of teacher retention include sense of belonging, sense of efficacy, and job satisfaction. Many personal and professional characteristics of a teacher also have been found to predict teacher retention. The purpose of this research was to explore how these factors predicted Technology and Engineering Educators' (TEE) teachers’ persistence to remain in the teaching profession. Furthermore, this research sought to identify programs that existed to help support TEE teachers in their persistence intentions.

This research found teacher job satisfaction was a …

Assessing The Role Of Magnetite In Municipal Wastewater Treatment, Patricia Ayaa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Some municipal wastewater treatment (MWWT) facilities have adopted magnetite in their treatment processes through a technology called BioMag® to meet effluent regulatory requirements for total nitrogen and total phosphorus. However, there is limited information on the mechanisms and efficiency of magnetite in the removal of nitrogen (N) and phosphorus (P) from wastewater. This research, therefore, estimated its effectiveness in the removal of these nutrients, with a case study of the Marlay-Taylor Water Reclamation Facility in Maryland. The intervention analysis model was used, but a new forecasting approach to the model was proposed to fit the data in this study and …

Release Of Large Water Droplets, Jeffrey N. Fonnesbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water is familiar to all human beings and water droplets are an integral part of our daily lives. From irrigation sprinklers to waterfalls we can observe the formation of water droplets. For most, the droplets are so common and mundane that no thought is given to how the droplets form. Scientists have spent many decades detailing the processes that lead to droplet formation. Current theories and experiments agree quite well for specific cases such as pendant drop formation and jet breakup, but in regards to large volumes of free falling liquid there is very little experimental work to confirm the …

Advances In Process Understanding And Methods To Support River Temperature Modeling In Large Regulated Systems, Bryce A. Mihalevich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

River temperatures play a key role in determining the suitability of habitat for aquatic ecosystems. While thermal regimes are influenced by many factors, flow and temperature patterns in large rivers are often shaped by water development. As such, water management associated with large reservoirs and diversions have also altered aquatic ecosystems. As climate change introduces new climate and hydrologic patterns, the decisions water managers make to address changes in runoff may further impact aquatic ecosystems. This calls for robust modeling tools that can predict river and reservoir temperature responses to water management decisions over large regions. However, highly variable topography …

Evaluation Of Hydrograph Separation Techniques With Uncertain End-Member Composition, Eileen Page Lukens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to precipitation and temperature occurring as a result of climate change can influence water sources (such as groundwater or snowmelt) that contribute to stream flow in a watershed. This is significant, as shifts in the amount of water coming from different water sources can shape watershed management decisions. One technique often used to investigate changes in water sources is hydrograph separation, a mathematical tool that allows for the quantification of the amount of water that came from different water sources. However, it can be difficult to perform hydrograph separations in remote watersheds as there may be insufficient infrastructure, i.e. …

Using Experiments, 3d Scanning, And Computational Fluid Dynamics To Analyze Variance In Minor Loss Coefficients, Adam B. Pack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As water moves through pipes, it loses energy. The energy losses are due to friction and the minor losses associated with various pipe fittings, which change the direction of flow. Pipe bends, or elbows, are a common pipe fitting and a significant source of energy loss in piping systems. This research was performed to better understand the variability of energy loss due to different pipe elbow designs and to investigate methods to replicate these losses using numerical simulations.

Eight pipe elbows, all 3-inch, 90-degree, schedule 40 PVC elbows that vary by radius of curvature and/or end connection type, were tested …

Exploring The Effects Of Upstream Disturbances On Elbow Meter Performance With Numerical Modeling Applications, Riley D. Manwaring

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Physical data was collected for a 6-in. long-radius elbow meter in order to determine the effects of certain upstream disturbances on its metering performance. Discharge coefficients are calculated for each of the three tested configurations at various installation distances between the upstream disturbance and the elbow meter. Computational Fluid Dynamics (CFD) software was used to determine which turbulence models most accurately modeled the observed physical results in order to provide a base from which to model the effects of additional upstream disturbances not modeled in this study.

Factors Affecting United States Geological Survey Irrigation Freshwater Withdrawal Estimates In Utah, J. Levi Manley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah is, on average, one of the driest states in the United States, second only to Nevada, and drier conditions are projected. Irrigation is the largest water user in the state, representing about 80% of the total freshwater withdrawn each year. Withdrawals are obtained from sources like reservoirs or streams, or underground water from wells and springs, and supplied for use. The United States Geological Survey, a reputable federal science agency, has provided irrigation freshwater withdrawal estimates every five years since 1950. Understanding what factors affect irrigation withdrawals can better inform water resource planning to reduce withdrawals and conserve surface …

Quantifying The Dynamics Of An Idealized Oil-Plume In Stratified Environment Using Direct Numerical Simulations, Jasmin Ahmed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Deep-water oil spills such as the incident in the northern Gulf of Mexico 2010, produce turbulent oil plumes. Multiphase turbulent plumes under stratification are simulated to understand the dynamics of oil plume in oceanic environment. The evolution of the plume is strongly affected by the level of turbulent mixing during the rise of oil through the stratified water. The relative velocity due to the difference in density between oil and water causes slip of oil in water. The plume has been modeled as a two fluid mixture-model, which allows the use of one continuity and momentum equation for the oil-water …

Long Term Feasibility Of Inductive Power Transfer Systems Embedded In Concrete Pavement Panels, Nathan J. Raine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Electric vehicles (EVs) have a variety of issues that prevent widespread acceptance. Range limitations, charging times, and lack of accessible locations are all viable concerns when considering the future of EVs. This research seeks to address lack of useable infrastructure and battery life by embedding wireless chargers directly into roadway concrete. These embedded chargers would make it possible to charge an EV while it is in transit, addressing many concerns associated with owning an EV.

Embedding a wireless charger, or Inductive Power Transfer System (IPTS), can cause premature failure in the concrete. To determine the long-term feasibility of the technology, …

The Effect Of Level Of Immersion On Learning In A Virtual Maintenance Training Task, Kendall Anne Carmody

Theses and Dissertations

The purpose of this study was to examine the effect of immersion on four constructs related to learning which included: memory retention, engagement, learning performance in the form of knowledge acquisition, and perceived learning in a virtual maintenance training task. The study posed four research questions and strived to determine how these constructs are impacted by two different levels of immersion during a virtual maintenance training task by means of either (a) a desktop computer and keyboard; Low-immersion Virtual Reality (LiVR) or (b) a virtual reality headset and controllers; High-immersion Virtual Reality (HiVR). To achieve this, a between-subjects experimental design …

Feasibility Study Of Regional Air Mobility Services For High Priority Transportation In The San Joaquin Valley, Julia Roa, Joseph Oldham

Mineta Transportation Institute

Regional Air Mobility (RAM) focuses on building upon existing airport infrastructure to transport people and goods using innovative aircraft that offer a huge improvement in efficiency, affordability, and community-friendly integration over existing regional transportation options. These aircraft, which typically carry less than 20 passengers or an equivalent weight in cargo, are flexible in terms of where they can take off and land, even using existing runways and infrastructure to maximize compatibility with today’s airports. This project examines the feasibility of RAM supporting high-speed transportation for high-priority passenger and cargo movement within Fresno County and connection to coastal urban centers. Some …

Protecting Our Community From The Hidden Vulnerabilities Of Today’S Intelligent Transportation Systems, Shahab Tayeb

Mineta Transportation Institute

The ever-evolving technology interwoven into the transportation industry leaves it frequently at risk for cyber-attacks. This study analyzes the security of a common in-vehicle network, the Controller Area Network (CAN), standard in most vehicles being manufactured today. Like many other networks, CAN comes with inherent vulnerabilities that leave CAN implementations at risk of being targeted by cybercriminals. Such vulnerabilities range from eavesdropping, where the attacker can read the raw data traversing the vehicle, to spoofing, where the attacker can place fabricated traffic on the network. The research team initially performed a simulation of CAN traffic generation followed by hardware implementation …

Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

Studying accessibility, including the resilience of city transportation networks, is critical to understand how these networks influence individuals’ mobility and lives. This study developed an analytical research framework to examine the resilience of accessibility to emergency and lifesaving facilities under the threats of natural hazards such as earthquakes and wildfires. With a cumulative-opportunity approach, the authors measured accessibility by counting emergency and lifesaving facilities (including parks, schools, hospitals, roads, and fire stations) that can be reached by driving at the census tract level in San Fernando Valley, CA. With the calculated accessibility, the authors run simulations to collect data showing …

Development Of Modeling And Simulation Platform For Path-Planning And Control Of Autonomous Underwater Vehicles In Three-Dimensional Spaces, Sai Krishna Abhiram Kondapalli

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous underwater vehicles (AUVs) operating in deep sea and littoral environments have diverse applications including marine biology exploration, ocean environment monitoring, search for plane crash sites, inspection of ship-hulls and pipelines, underwater oil rig maintenance, border patrol, etc. Achieving autonomy in underwater vehicles relies on a tight integration between modules of sensing, navigation, decision-making, path-planning, trajectory tracking, and low-level control. This system integration task benefits from testing the related algorithms and techniques in a simulated environment before implementation in a physical test bed. This thesis reports on the development of a modeling and simulation platform that supports the design and …

Development Of A Fuzzy Logic Model-Less Aircraft Controller, Christopher M. Scott

Electrical & Computer Engineering Theses & Dissertations

The Modeling and Control for Agile Aircraft Development (MCAAD) group at NASA Langley Research Center(LaRC) is developing techniques for Real-Time Global Modeling (RTGM) and Robust Learning Control (RLC) for NASA’s Transformational Tools and Technologies Project. This project seeks to develop a systematic approach to reduce the iterative nature of aircraft design by introducing a model-less control law and enabling inflight aerodynamic modeling and controller design. The development of the flight control system without prior knowledge of the aircraft aerodynamic model makes use of TakagiSugeno-Kang fuzzy logic inference systems for pitch and roll controllers and are tested in various simulations and …

Hierarchical Value Decomposition For Effective On-Demand Ride Pooling, Hao Jiang, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

On-demand ride-pooling (e.g., UberPool, GrabShare) services focus on serving multiple different customer requests using each vehicle, i.e., an empty or partially filled vehicle can be assigned requests from different passengers with different origins and destinations. On the other hand, in Taxi on Demand (ToD) services (e.g., UberX), one vehicle is assigned to only one request at a time. On-demand ride pooling is not only beneficial to customers (lower cost), drivers (higher revenue per trip) and aggregation companies (higher revenue), but is also of crucial importance to the environment as it reduces the number of vehicles required on the roads. Since …

Message-Locked Searchable Encryption: A New Versatile Tool For Secure Cloud Storage, Xueqiao Liu, Guomin Yang, Willy Susilo, Joseph Tonien, Rongmao Chen, Xixiang Lv

Research Collection School Of Computing and Information Systems

Message-Locked Encryption (MLE) is a useful tool to enable deduplication over encrypted data in cloud storage. It can significantly improve the cloud service quality by eliminating redundancy to save storage resources, and hence user cost, and also providing defense against different types of attacks, such as duplicate faking attack and brute-force attack. A typical MLE scheme only focuses on deduplication. On the other hand, supporting search operations on stored content is another essential requirement for cloud storage. In this article, we present a message-locked searchable encryption (MLSE) scheme in a dual-server setting, which achieves simultaneously the desirable features of supporting …

An Empirical Study Of Memorization In Nlp, Xiaosen Zheng, Jing Jiang

Research Collection School Of Computing and Information Systems

A recent study by Feldman (2020) proposed a long-tail theory to explain the memorization behavior of deep learning models. However, memorization has not been empirically verified in the context of NLP, a gap addressed by this work. In this paper, we use three different NLP tasks to check if the long-tail theory holds. Our experiments demonstrate that top-ranked memorized training instances are likely atypical, and removing the top-memorized training instances leads to a more serious drop in test accuracy compared with removing training instances randomly. Furthermore, we develop an attribution method to better understand why a training instance is memorized. …

Koh-Based Modified Solvay Process: Optimization And Kinetics Studies, Aya Abdel-Hamid Mourad

Dissertations

While desalination of seawater is important for meeting the water demand, the technology produces large volumes of reject brine and CO₂, causing environmental pollution. Solvay process (based on ammonia, NH₃) and modified Solvay process (based on calcium oxide, CaO) try to manage these wastes. However, more attention is needed to overcome different limitations of these processes such as, alkaline solubility, operating temperature, maintaining high pH value, and low sodium (Na⁺) removal efficiency, which does not exceed 35%. The aim of this work is to introduce an alternative alkaline, namely potassium hydroxide (KOH) and investigate …