Engineering Commons^™

Development Of A Water Temperature Modeling Platform To Support Short- And Long-Term Water Temperature Management In Reservoir-River Systems, Michael Deas, Yung-Hsin Sun, John Degeorge, Benjamin T. Saenz, Thomas A. Evans, Scott Burdick-Yahya, Stephen Andrews, Jeff Schuyler, William Candy, Lin Zheng, Scott Wells, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

The U.S. Department of the Interior, Bureau of Reclamation (Reclamation) supports water temperature management for fishery species protection in downstream river reaches below Central Valley Project (CVP) reservoirs in the Sacramento, American, and Stanislaus River systems. The Water Temperature Modeling Platform (WTMP) Project was initiated to modernize and enhance modeling capabilities to predict summer–fall water temperature through reservoir cold water pool management using temperature control facilities designed for temperature management. The WTMP supports forecasts, historical analyses, and long-term planning efforts and advances previous modeling approaches by using an integrated modeling platform. This platform includes a data management system that acquires …

Enhancement Of Spin Transport Properties In Angled-Channel Graphene Spin Valves Via Hybrid Spin Drift-Diffusion, Samuel Olson, Kaleb Hood, Otto Zietz, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

Graphene has promise as a channel connecting separate units of large-scale spintronic circuits owing to its outstanding theoretical spin transport properties. However, spin transport properties of experimental devices consistently fall short of theoretical estimates due to impacts from the substrate, electrodes, or defects in the graphene itself. In this study, we fabricate both traditional non-local spin valves (NLSVs) and novel hybrid drift-diffusion spin valves (HDDSVs) to explore the impact of charge current and AC spin injection efficiency on spin transport. HDDSVs feature channel branches that allow investigation of charge-based spin drift enhancement compared to diffusion-only configurations. We investigate the modulation …

From Model To Behavior: Methodological Challenges In Using Fuzzy Cognitive Maps To Represent Mental Models, Catherine Elizabeth Moore

Dissertations and Theses

This dissertation examines the use of Fuzzy cognitive maps (FCMs) as representations of mental models and how these representations connect to individual behavior. Fuzzy cognitive maps (FCMs) are semi-quantitative models that encode cause-and-effect structures as directed graphs. They are frequently used to represent individuals' knowledge structures/mental models and should in theory correlate to actions and decisions of individuals; however, this correlation has yet to be explored in a systematic manner. This dissertation represents the first step in experimental research on the connection between FCMs and individual behavior. It examines two theories of how humans use mental models, one based on …

Developing Workflows For Passive Acoustic Detection Of Bedload Transport, Quinn Morgan

Dissertations and Theses

Bedload transport is defined as the amount of sediment, including gravel and rocks, traveling down stream. Monitoring bedload transport is important for river safety, hydrological studies and conservation efforts. Existing methods of directly measuring bedload transport (or bedload flux) involve lowering a collection device into a river and measuring the sediment collected; which can be expensive and time consuming. Hydroacoustic sensors, such as hydrophones, have had success tracking bedload flux remotely. This works by measuring the relatively high frequency of sediment impacts to map onto total bedload transported. No perfected method for detection of sediment generated noise (SGN) currently exists. …

Evaluation Of User Interactions And Preferences Of Shared Bicycle And Pedestrian Transit Platforms, Nathan Mcneil, Sirisha Kothuri, Jennifer Dill, Chris Monsere, Elizabeth Yates, Julia Plotts

Civil and Environmental Engineering Faculty Publications and Presentations

Shared bike and bus platforms have been deployed in an effort to minimize conflicts between bicycles and buses (and other motor vehicles) on streets with bike lanes and bus transit service. This paper assesses bicycle/micromobility user and pedestrian behavior in shared bicycle and transit platforms along a bus rapid transit corridor in Portland, OR. Research objectives include understanding interactions between these users and potential conflicts between people on foot (or wheelchair/mobility devices) who are waiting for, boarding, and/or alighting a bus and people on bicycles riding in the bike lane. The research also assessed how well the shared transit platforms …

Clinic Vs. Daily Life Gait Characteristics In Patients With Spinocerebellar Ataxia, Vrutangkumar V. Shah, Daniel Muzyka, Adam Jagodinsky, Hannah Casey, James Mcnames, Mahmoud El-Gohary, Kristen Sowalsky, Delaram Safarpour, Patricia Carlson-Kuhta, Fay B. Horak, Christopher M. Gomez

Electrical and Computer Engineering Faculty Publications and Presentations

Background:

Recent findings suggest that a single gait assessment in a clinic may not reflect everyday mobility.ObjectiveWe compared gait measures that best differentiated individuals with spinocerebellar ataxia (SCA) from age-matched healthy controls (HC) during a supervised gait test in the clinic vs. a week of unsupervised gait during daily life.

Methods: Twenty-six individuals with SCA types 1, 2, 3, and 6, and 13 (HC) wore three Opal inertial sensors (on both feet and lower back) during a 2-minute walk in the clinic and for seven days in daily life. Seventeen gait measures were analyzed to investigate the group differences using …

Digital Strategies And Non-Conventional Sources Of Innovation: Analysis Of Causal Relationships Using Interpretive Structural Modeling, Ines M. Ferinha, Fernando A. F. Ferreira, Neuza C. M. Q. F. Ferreira, Edwin Garces, Tugrul Daim

Engineering and Technology Management Faculty Publications and Presentations

Digitalization appears to have sped up in recent years, and many companies have seen their business models changed irreversibly. In this context, small and medium-sized enterprises (SMEs) should adopt different business approaches that help these firms thrive and maintain and/or create sustainable competitive advantages. SMEs’ specificities can present obstacles to this adaptation process, yet these challenges may turn out to be the greatest allies of these companies if they stimulate swift, quick transformations. This study sought to develop an analysis system that identifies appropriate digital strategies and non-conventional sources of innovation, which can thus promote sustainable SME innovation. To achieve …

Proceedings Of The 33rd United States – Japan Bridge Engineering Workshop, David Y. Yang

Civil and Environmental Engineering Faculty Publications and Presentations

This report summarizes the 33rd United States–Japan Bridge Engineering Workshop, an event that convenes bridge engineers from both countries. The workshop serves as a platform to exchange innovative ideas and technologies, as well as to share crucial knowledge and lessons learned, all with the aim of advancing bridge engineering. The 33rd workshop specifically addressed transportation asset management and seismic retrofitting, two subjects of increasing importance to both the United States and Japan. The report details the workshop's discussions on topics relevant to bridge engineers.

Pressure And Force Dynamics In Artificial Muscle Actuators: A State-Space And Optimization-Based Approach, Mohammad Elzein

Dissertations and Theses

This two-part investigation explores the dynamic behavior of braided pneumatic actuators (BPAs) under bio-inspired pulse modulation, with the aim of improving their biomimetic force output and control. The first study examines the effect of pulse length and inter-pulse timing on BPA performance, revealing that force output is highly sensitive to the temporal structure of input pulses mirroring biological muscle behavior. Using dual-pulse actuation schemes, the results demonstrate that force responses exceed the additive contributions of individual pulses, with peak amplification occurring consistently at a 27 ms inter-pulse gap. Shorter pulse lengths (10–20 ms) yielded the highest normalized force increases, up …

Free-Running Ring Oscillators For Crystal-Free Communication Systems: Design, Simulation Challenges, And Frequency Stability Improvements, Haziq Rohail

Dissertations and Theses

This thesis presents techniques for enhancing the frequency stability of ring oscillators (ROs) for crystal-free wireless communication systems. The first major contribution is a tutorial-style study of frequency stability metrics, providing clear definitions, conversions methods, and comparative analysis of commonly used figures of merit such as phase noise, Allan deviation, and jitter. The second contribution addresses the challenges of simulating phase noise in free-running ROs. Key techniques including Periodic Steady-State Noise (PNoise), Harmonic Balance Noise (HBNoise), and transient noise analysis are evaluated in terms of accuracy, convergence behavior, and simulation runtime. Based on these results, practical guidelines are offered for …

Transfer Learning-Based Multi-Sensor Approach For Predicting Keyhole Depth In Laser Welding Of 780dp Steel, Byeong-Jin Kim, Young-Min Kim, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Penetration depth is a critical factor determining joint strength in butt welding; however, it is difficult to monitor in keyhole-mode laser welding due to the dynamic nature of the keyhole. Recently, optical coherence tomography (OCT) has been introduced for real-time keyhole depth measurement, though accurate results require meticulous calibration. In this study, deep learning-based models were developed to estimate penetration depth in laser welding of 780 dual-phase (DP) steel. The models utilized coaxial weld pool images and spectrometer signals as inputs, with OCT signals serving as the output reference. Both uni-sensor models (based on coaxial pool images) and multi-sensor models …

Design And Evaluation Of An Electromagnetic Band Gap Structure For Self-Interference Reduction In Mmwave Full-Duplex Systems, Adewale Kehinde Oladeinde

Dissertations and Theses

Full-duplex (FD) wireless is a new technology that allows a device to transmit and receive at the same time and on the same frequency band. It has the potential to double the capacity and spectral efficiency of a wireless link compared to the family of conventional half-duplex wireless systems. The key challenge in implementing FD wireless communication is self-interference (SI): a node's transmitting signal generates significant interference to its receiver. Several previous studies have demonstrated the potential to reduce SI and develop FD radios; however, these studies are mostly limited to sub-6 GHz systems. Previous and on-going research explored various …

Emergence Of Norms In The Presence Of Social Network Structure In A Stochastic Evolutionary Game Theory Model, Parker Foresman

Dissertations and Theses

In their 2000 paper, The Emergence of Classes in a Multi-Agent Bargaining Model, Axtell, Epstein, and Young introduced an agent-based bargaining model to study how social norms can emerge and persist from the decentralized, asynchronous interactions of individual agents in the presence of noise, even when these agents have no predefined preferences or advantages. This thesis extends their model by incorporating structured interaction networks, allowing us to investigate how the topology of agent interactions influences long-run dynamics and norm formation. Using a custom simulation package built in the Julia programming language, we replicate the original results under a complete …

Combined Passive And Active Ultrasonic Stress Wave Monitoring Of A Full-Scale Laboratory Reinforced Concrete Bridge Column Subject To Reverse-Cyclic Lateral Loading, Niklas Epple, Thomas Schumacher, A. K. M. Golam Murtuz, Ernst Niederleithinger, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Effective monitoring of reinforced concrete structures requires techniques that detect early-stage material change and active, localized cracking. This study investigates a combined structural health monitoring approach using passive acoustic emission and active ultrasonic methods on a full-scale reinforced concrete bridge column subjected to reverse-cyclic lateral loading. Active monitoring, based on coda wave interferometry, was used to track changes in wave velocity and waveforms, while passive acoustic emission monitoring was used to detect crack activity. The instrumentation consisted of three embedded ultrasonic transducers and three surface-mounted acoustic emission sensors. The results show that active ultrasonic monitoring is most effective prior to …

Translating Soil Salinity To Agricultural Salt Stress: Key Salt-Tolerance Mechanisms For Agrohydrologic Models, Josh Gottlieb, Dvir Ochman, Cheng-Wei Huang, Jean-Christophe Domec, Nimrod Schwartz, Samantha Hartzell

Civil and Environmental Engineering Faculty Publications and Presentations

Summary:

Salt stress has a detrimental impact on crop yield and survival rates, which salt-tolerant cultivars can resist through numerous adaptive mechanisms. Most models of salt stress impacts on productivity and water use employ empirical or simplified schemes to represent salt-adaptive traits. However, with an increased understanding of these physiological tolerance mechanisms and emergent measurement techniques for monitoring key salinity dynamics, the potential for developing mechanistic agrohydrological models of the soil-plant-atmosphere continuum has grown. This perspective highlights strategies for modeling salt tolerance mechanisms, including root system architecture adaptation, salt filtration, adaptation of plant hydraulics, ion compartmentalization, and stomatal responses, to …

Isolation Enhancement Based On Tm010 And Te30 Mode Characteristics In A Patch Antennas Using Genetic Algorithm Optimization For Ku-Band Applications, Muddineni Raveendra, U. Saravanakumar, P. Padmaloshani, P. Saam Prasanth Dheeraj, Anand Anbalagan, R. Sreelakshmy

Electrical and Computer Engineering Faculty Publications and Presentations

This paper proposes a novel technique to enhance isolation in rectangular patch antennas by leveraging the mode characteristics of TM010 and TE30 to achieve better than −40 dB between the transmitter and receiver with dual‐polarization features. The primary innovation of this work lies in achieving significant isolation enhancement solely by combining two resonant modes with orthogonal polarizations, without incorporating any additional design elements such as parasitic components or decoupling structures. To validate the isolation enhancement based on these mode characteristics, a pair of rectangular transmitter and receiver patch antennas was designed to operate in the frequency range from 14 to …

Prospects For Telemedicine Adoption: Prognostic Modeling As Exemplified By Rural Areas Of Usa, Jisun Kim, Hamad Alanazi, Tugrul Daim

Engineering and Technology Management Faculty Publications and Presentations

Experts predict that in the majority of countries state healthcare expenditures will continue to rise. Usage of telemedicine applications – the use of information and communications technologies (ICT) in order to provide clinical health care at a distance – will help optimize the costs of healthcare in the long-term. The main advantages of telemedicine include reducing the number of doctor’s errors, saving both patients and physicians time, and improving the efficiency of healthcare organizations. It also ensures timely and quality services for large segments of the population living in remote territories with difficult socio-economic conditions, particularly rural areas.The paper forecasts …

Sae Baja Drivetrain Capstone 2024-2025, Leslie Alvarez Cisneros

University Honors Theses

This thesis reviews the 2024-2025 Baja SAE Drivetrain capstone project. The Baja SAE competition mimics real world engineering problems where teams of students design and build off-road vehicles that can handle tough, rough terrain. The objective of this capstone was to design a functional and reliable drivetrain system for the vehicle, within the constraints of a limited budget and the SAE competition guidelines. As part of a 12-member capstone team divided into three subgroups: frame, suspension, and drivetrain. As part of a four person drivetrain team, we picked up where the 2023-2024 team left off by relying on their past …

Towards A Robust Hydrologic Data Assimilation System For Hurricane-Induced River Flow Forecasting, Peyman Abbaszadeh, Fatemah Gholizadeh, Keyhan Gavahi, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The Hybrid Ensemble and Variational Data Assimilation framework for Environmental Systems (HEAVEN) is a method developed to enhance hydrologic model predictions while accounting for different sources of uncertainties involved in various layers of model simulations. While the effectiveness of this data assimilation in forecasting streamflow has been proven in previous studies, its potential to improve flood forecasting during extreme events remains unexplored. This study aims to demonstrate this potential by employing HEAVEN to assimilate streamflow data from United States Geological Survey (USGS) stations into a conceptual hydrologic model to enhance its capability to forecast hurricane-induced floods across multiple locations within …

Distributed Energy Resources: A Systematic Literature Review, Midrar Adham, Sean Keene, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

The traditional power grid, characterized by its centralized nature and one-way power flow, has long been the backbone of electricity supply and distribution. Grid operators have historically found various ways to accurately predict demand, anticipate faults, and prepare appropri- ate responses. However, with the rapid integration of Distributed Energy Resources such as Photovoltaic, storage systems, grid-interactive generation, and flexible-load assets, energy consumption and production patterns have become less predictable, transforming the grid into a two-way power flow system. Managing the potential of these Distributed Energy Resources requires advanced management systems that provide monitoring, coordination, and aggregation capabilities to …

Range-Dependent Meso-Scale Geoacoustic Seabed Quantification, Tim Sonnemann, Jan Dettmer, Charles W. Holland, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

This study presents a probabilistic one-step two-dimensional (2D) inversion method of spherical-wave reflection coefficient data to estimate the range-dependent structure and geoacoustic parameters along a track. The approach of inverting such datasets independently as one-dimensional (1D) layered models and merging them to a 2D section is feasible but computationally expensive. This study demonstrates a more parsimonious 2D parametrization for active source data recorded on a towed hydrophone array. The comparison of data variance reduction for 1D- and 2D-based results clearly favors the 2D parametrization described here.

Time Synchronization For 5g And Tsn Integrated Networking, Zixiao Wang, Zonghui Li, Cheng Long, Yiming Zheng, Bo Ai, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Emerging industrial applications involving robotic collaborative operations and mobile robots require a more reliable and precise wireless network for deterministic data transmission. To meet this demand, the 3rd Generation Partnership Project (3GPP) is promoting the integration of 5th Generation Mobile Communication Technology (5G) and Time-Sensitive Networking (TSN). Time synchronization is essential for deterministic data transmission. Based on the 3GPP’s vision of the 5G and TSN integrated networking with interoperability, we improve the time synchronization of TSN to conquer the multi-gNB competition, re-transmission, and mobility problems for the integrated 5G time synchronization. We implemented the improvement mechanisms and systematically validated the …

Influencing Factors Of Angle-Of-Arrival Estimator Based On Deep Learning, Guohao Pang

Dissertations and Theses

Deep learning (DL)-based angle-of-arrival (AoA) estimation offers significant advantages over traditional signal processing methods, especially in complex and high-noise environments. However, situational complexity and differences in hardware can significantly impact the estimator's performance. It is therefore of interest to investigate the relationship between the performance of deep learning models and the variation of physical parameters such as the number of signal sources, the number of receiving antennas, and the signal-to-noise ratio (SNR). In this study, we investigate the impact of these variations on deep learning-based AoA estimation by systematically analyzing how the variations in the characteristics of the received signal …

Price-Signal-Based Control Strategy For Heat Pump Water Heaters In Demand Response Applications, Othman A. Murad

Dissertations and Theses

This work presents a price-signal-based control strategy for residential Heat Pump Water Heaters (HPWHs) aimed at reducing electricity costs and shifting load away from high-price periods. By integrating the California Load Flexibility Research and Development Hub (CalFlexHub) prototype price signals, the Consumer Technology Association (CTA-2045-B) communication protocol, and the Object-oriented, Controllable, High-resolution Residential Energy (OCHRE) simulation framework, a rule-based controller was developed to align HPWH operation with dynamic electricity pricing while maintaining hot water availability.

The control strategy was evaluated through two case studies: one using a fixed water draw profile under varying levels of price signal foresight, and another …

Restricted Nonlinear Simulations Of Flow Over Riblets: Characterizing Drag Reduction And Its Breakdown, Xiaowei Zhu, Bianca Fontanin Viggiano, Benjamin A. Minnick, Dennice Gayme

Mechanical and Materials Engineering Faculty Publications and Presentations

The restricted nonlinear (RNL) model is employed as low-order representation of turbulent flow over riblets at 𝑅𝑒𝜏 ≈ 395. Comparisons with direct numerical simulations (DNS) verify the ability of the model to accurately capture low-order statistics, as well as trends in drag-alteration and secondary motion as a function of riblet geometry and spacing. We demonstrate the ability of the RNL model to reproduce additional flow features by decomposing the roughness function to isolate contributions from the total stress and comparing its predictions to DNS data. An analysis of the spectra of Reynolds shear stress shows that the RNL model captures …

Levels Of The Nicotine Analog 6-Methyl Nicotine As A Naturally Formed Tobacco Alkaloid In Tobacco And Tobacco Products, James F. Pankow, Wentai Luo, Kevin J. Mcwhirter, Mohana Sengupta, Robert M. Strongin

Civil and Environmental Engineering Faculty Publications and Presentations

S-6-methyl nicotine (S-6MN) has appeared as a nicotine substitute in commercial electronic e-cigarette products and pouches, including with the claim that such use is not regulated under current U.S. law. This work describes an analytical chemistry based search for the natural S/R presence of 6MN and three other MN compounds in additive-free cured leaf tobaccos and in multiple commercial tobacco products. The samples were extracted using 5 N NaOH, then methyl t-butyl ether. The extracts were analyzed using gas chromatography (GC) with mass spectrometric (MS) detection, and liquid chromatography (LC) with high resolution MS/MS detection. GC peaks with the correct …

The Electrostatic Charge On Exuded Liquid Drops, Schuyler Arn, Pablo Illing, Joshua Mendéz Harper, Justin C. Burton

Electrical and Computer Engineering Faculty Publications and Presentations

Fluid triboelectrification, also known as flow electrification, remains an under-explored yet ubiquitous phenomenon with potential applications from material science to planetary evolution. Building upon previous efforts to position water within the triboelectric series, we investigate the charge on individual, millimetric water drops falling through air. Our experiments measured the charge and mass of each drop using a Faraday cup mounted on a mass balance, and connected to an electrometer. For pure water in a glass syringe with a grounded metal tip, we find the charge per drop (Δ/Δ) was approximately -5 pC g to -1 pC g. This was independent …

Predicting Strut Geometry Of Pcl And Dmso2 Biocomposites From Nozzle To Deposition In Bio-Scaffold 3d Printing, Jae-Won Jang, Kyung-Eun Min, Jun-Hee Park, Cheolhee Kim, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

The field of tissue engineering increasingly demands accurate predictive models to optimize the 3D printing process of bio-scaffolds. This study presents a unified numerical model that predicts extrusion velocity and strut diameter based on printing conditions and the material properties of polycaprolactone (PCL) and dimethyl sulfone (DMSO2) composites. The extrusion velocity was simulated using Navier–Stokes equations, while the strut diameter was calculated via a surface energy model. For PCL, the extrusion velocity showed a temperature coefficient of 23.3%/°C and a pressure coefficient of 19.1% per 100 kPa; the strut diameter exhibited a temperature coefficient of 21.6%/°C and a pressure coefficient …

Detecting And Analyzing Frequency Events In Power Systems Using Tunable Parameters-Based Algorithms: Development, Optimization, And Analysis, Hussain A. Alghamdi

Dissertations and Theses

This dissertation addresses the challenge of detecting frequency events in diverse power systems by enhancing existing frequency event detection methods through detection process modifications and developing unique tunable parameters. Since system characteristics differ across regions, frequency event detection algorithms must be customized by domain experts for each balancing area using tunable parameters. By optimizing these parameters for specific power system, the algorithms can accurately detect frequency events and can also be used for further analysis to determine trends in frequency events over time, ensuring system stability.

This dissertation focuses on the enhancement and optimization of frequency event detection algorithms. These …

Managing Happiness In The Mexican Maquiladora Industry: A Turnover Management Challenge, Claudia M. Burgos Cruz, Reyna Virginia Barragan Quintero, Angel Contreras Cruz

Engineering and Technology Management Faculty Publications and Presentations

This study explores a turnover management case by implementing exploratory Human-Centered Design (HCD) strategies, combining a collaborative tool in a Mexican maquiladora in Tecate, Baja California. To reduce turnover, the tool was designed, prototyped, and tested to foster the emotional well-being of employees, enhance employee engagement, and promote a sense of belonging in the workplace. The company leaders and managers were trained to use the HCD prototypes, such as the Happiness Dashboard, a visual feedback system using emojis to collect data during regular shifts, and the Gemba Walks, a method for collecting information through observing and interacting with workers. Organizational …