Engineering Commons^™

Numerical Study Of Cone Penetration In Calcareous Sands: Investigating Cone Tip Resistance Correction Factors For Crushable Soils, Stephanie Michelle Hyder

Dissertations and Theses

The cone penetration test (CPT) is used to characterize the behavior and properties of soils, including the susceptibility to earthquake liquefaction triggering. The cone tip resistance relates to liquefaction susceptibility through relative density, where relative density is closely related to both cone tip resistance and liquefaction susceptibility. Currently, published methods of estimating liquefaction potential (i.e., cyclic resistance ratio) are based on silica sands and do not properly characterize calcareous sands. The measured cone tip resistance in calcareous sands is lower than in silica sands at the same relative density; this difference is generally attributed to the higher compressibility of calcareous …

Comparison Of Conventional And Adaptive Acoustic Beamforming Algorithms Using A Tetrahedral Microphone Array In Noisy Environments, Megan Brittany Ewers

Dissertations and Theses

In situ acoustic measurements are often plagued by interfering sound sources that occur within the measurement environment. Both adaptive and conventional beamforming algorithms, when applied to the outputs of a microphone array arranged in a tetrahedral geometry, are able to capture sound sources in desired directions and reject sound from unwanted directions. Adaptive algorithms may be able to measure a desired sound source with greater spatial precision, but require more calculations and, therefore, computational power. A conventional frequency-domain phase-shift algorithm and a modified adaptive frequency-domain Minimum Variance Distortionless Response (MVDR) algorithm were applied to simulated and recorded signals from a …

Understanding Quadrature Modulation By Designing A 7mhz Iq Test Bench To Encode The Polybius Square, William Lee Bradley

Dissertations and Theses

This thesis outlines the design of an IQ Test Bench that allows for experimentation of quadrature modulation techniques. Quadrature modulation utilizes two signals I and Q, 90° out of phase from each other, to greatly increase communication data rates. Using Desmos, a thorough mathematical analysis of waveform mixing is presented, and constellation diagrams are plotted from the results. From this an ancient fire signaling technique known as the Polybius Square is encoded into the system. The IQ Test Bench is built from fundamental components that would be contained within an RFFE: a local oscillator and two frequency mixers. The LO …

Uncertainty Quantification Of Live Load Effect In Buried Rc Box Culverts, Mohd Firoj

Dissertations and Theses

Although buried and mostly invisible to the traveling public, bridge-sized culverts (i.e., culverts with span around or longer than 20 ft) account for a large proportion of state-managed bridges. As per Oregon Department of Transportation inventory, there are approximately 35,000 culverts in the state highway system. Among them, 10,862 are in poor conditions and need to be analyzed for load rating purposes. The prediction and understanding of live load effects in culverts are crucial to the design, evaluation, and life-cycle maintenance of culverts. These live load effects include maximum bending moments and shear forces at different critical cross sections.

This …

Probability Distribution Fitting For Censored Data: A Practical Guide For Survival Analysis Of Nbi Data For Concrete Bridge Decks In Oregon, Asmaa Almeshaileh

Dissertations and Theses

Many sophisticated statistical models and analyses have been proposed to analyze datasets derived from the national bridge inventory (NBI). These objectives range from creating an understanding of the factors that drive the deterioration of bridge members to providing agencies with quantitative information for their maintenance and repair decisions. As these models become increasingly sophisticated and difficult to comprehend and implement, practicing engineers and owners are less likely to use them. Often, however, grouping data intuitively, for example, per a select structure type or condition rating and analyzing them using prescriptive statistics such as distribution fitting, does not only lie in …

Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson

Dissertations and Theses

Rivers and estuaries provide numerous ecological, economic, and cultural resources. The value of these resources is greatly influenced by sediment transport processes, which can be affected by human activities and climate variability. A key driver of sediment transport in tidal rivers and estuaries is tidal asymmetry of velocity and bed stress, which can manifest from both non-linear tidal interactions and linear interactions among astronomical tidal constituents.

In this study, an analytical framework is developed to examine and describe the dynamics of bed stress asymmetry in semidiurnal, diurnal, and mixed-tide estuaries (Chapter 1). While tidal velocity asymmetry has been previously analyzed, …

A Bayesian Network-Based Methodology For Improved Bridge Load Rating And Asset Management, Jeffery Mark Roberts

Dissertations and Theses

From the day a new structure is made available for use, to the day that the structure is no longer able to fulfill an intended purpose, structural safety is a vital interest. Managing a portfolio of structures can be a difficult undertaking for an asset manager, particularly if different types of structures are being maintained. The goal is to manage assets in the most efficient manner which can be influenced by, at a minimum, safety and financial concerns.

A potential tool for an asset manager or owner is the use of Bayesian Networks (BNs). When a BN is used to …

Design And Characterization Of 2.4ghz Antennas For Wireless Sensor Applications, Luis Zogby Brennan

Dissertations and Theses

Wireless sensor networks benefit greatly from advances in circuit integration and miniaturization. However, antennas are bound to specific geometries both in terms of fundamental limits and their response to immediate surroundings. As such, various successful techniques for antenna miniaturization must still be carefully tested and characterized as part of the design process of a sensor system. The work presented here fully characterizes a number of miniaturized 2.4~GHz antennas and successfully integrates designs into a sensor system using the highly integrated Single Chip Micro Mote (SCµM), which uses a crystal-less radio design resulting in the requirement of only a …

Modeling Leaf-Level Transpiration: Exploring The Consequences Of Assumed Saturated Vapor Pressure In Leaves, Danlyn L. Brennan

Dissertations and Theses

Understanding the dynamics of water transport through leaf intercellular airspaces (IAS) and its impact on transpiration is crucial for accurate predictions of plant water use and ecosystem response to changing climates. This study investigates the implications of assuming undersaturation of water vapor in the IAS for transpiration predictions and explores potential modifications to standard modeling approaches.

A dynamic 1D soil-plant-atmosphere continuum using a stomatal optimization model (SPAC-SOT) framework was used to simulate the response of tree species, P. edulis, to prolonged drought and varying environmental conditions. Comparisons between two model assumptions (saturated vs. undersaturated IAS) reveal notable differences in …

Real-Time Length Sensing Of Braided Pneumatic Actuator Using Ir Time-Of-Flight Sensor, Luon B. Chung

Dissertations and Theses

Braided Pneumatic Actuators (BPAs) are used widely in robotics as artificial muscles because of their similar characteristics to biological muscles. When a BPA is pressurized, it expands in the radial direction and contracts in the longitudinal direction. The contraction generates a pulling force that is dependent on the input pressure and BPA length. Biological muscle also behaves in the same way where a pulling force is generated on a contraction. To control BPAs on a robot, the real-time pressure and length measurements are necessary. In this dissertation, I present a new method to measure length of BPAs in real-time using …

Multi-Agent Deep Reinforcement Learning For Radiation Localization, Benjamin Scott Totten

Dissertations and Theses

For the safety of both equipment and human life, it is important to identify the location of orphaned radioactive material as quickly and accurately as possible. There are many factors that make radiation localization a challenging task, such as low gamma radiation signal strength and the need to search in unknown environments without prior information. The inverse-square relationship between the intensity of radiation and the source location, the probabilistic nature of nuclear decay and gamma ray detection, and the pervasive presence of naturally occurring environmental radiation complicates localization tasks. The presence of obstructions in complex environments can further attenuate the …

Systematic Characterization Of Power Side Channel Attacks For Residual And Added Vulnerabilities, Aurelien Tchoupou Mozipo

Dissertations and Theses

Power Side Channel Attacks have continued to be a major threat to cryptographic devices. Hence, it will be useful for designers of cryptographic systems to systematically identify which type of power Side Channel Attacks their designs remain vulnerable to after implementation. It’s also useful to determine which additional vulnerabilities they have exposed their devices to, after the implementation of a countermeasure or a feature. The goal of this research is to develop a characterization of power side channel attacks on different encryption algorithms' implementations to create metrics and methods to evaluate their residual vulnerabilities and added vulnerabilities. This research studies …

Developing And Testing Low-Cost Air Cleaners For Safer Spaces During Wildfires, Brett William Stinson

Dissertations and Theses

Air cleaning reduces indoor exposure to fine particulate matter (PM_2.5) during wildfire events. However, resource and cost restraints may limit access to air cleaning during such an event, as both commercial devices and the high-rated MERV filters that homemade assemblies typically rely upon tend to be expensive and in short supply. With these barriers in mind, we sought to develop and evaluate the potential for air cleaners that use common household fabrics as filtration media. Evaluated designs use a box fan to move air across fabric filters; box fans are inexpensive and readily available to many households. Ultimately, …

A Hierarchical Decision Model To Evaluate Healthcare Organization's Readiness To Implement Clinical Decision Support Systems, Mohammed Oussama Laraichi

Dissertations and Theses

Clinical Decision Support Systems (CDSS) are essential tools for healthcare organizations as well as for healthcare providers to improve clinical care. However, successful implementation of CDSS can be challenging. Therefore, before implementing CDSS, it is crucial to assess the readiness of healthcare organizations to implement these tools.

Through a literature review, the first step of this research explores the concept of clinical decision support and CDSS, discussing their features, characteristics, and organizational hurdles to implementation. It also provides perspectives on CDSS adoption in the context of Information Systems and Health Technology. The review helped identify research gaps, objectives, and questions. …

Bodyslam: Feasibility Of Tracking Human Kinematics With Simultaneous Localization And Mapping (Slam), Sepehr Laal

Dissertations and Theses

We evaluated a new wearable technology that fuses inertial sensors and cameras for tracking human kinematics. These devices use on-board simultaneous localization and mapping (SLAM) algorithms to localize the camera within the environment. Significance of this technology is in its potential to overcome many of the limitations of the other dominant technologies. Our results demonstrate this system often attains an estimated orientation error of less than 1° and a position error of less than 4cm as compared to a robotic arm. This demonstrates that SLAM's accuracy is adequate for many practical applications for tracking human kinematics.

Realization Of Multi-Valued Logic Using Optical Quantum Computing, Sophie Choe

Dissertations and Theses

Quantum computing is a paradigm of computing using physical systems, which operate according to quantum mechanical principles. Since 2017, functioning quantum processing units with limited capabilities are available on the cloud. There are two models of quantum computing in the literature: discrete variable and continuous variable models. The discrete variable model is an extension of the binary logic of digital computing with quantum bits |0⟩ and |1⟩ . In the continuous variable model, the quantum state space is infinite-dimensional and the quantum state is expressed with an infinite number of basis elements.

In the physical implementation of quantum computing, however, …

Uncertainty Quantification And Fragility Development Of Deteriorating Rc Bridge Piers, Ayush Bhandari

Dissertations and Theses

Corrosion can reduce structural capacity and increase the risk of bridge damage/failure under extreme events. The impact of corrosion on seismic fragility of bridges has been well studied. However, the methodology used in most existing studies requires detailed information on the structural design and condition of a bridge, which is a major hindrance in conducting seismic risk assessment for a large population of bridges. Furthermore, existing studies do not adequately address the time-dependency of uncertainties associated with fragility curve development. This study presents a methodology to generate time-dependent seismic fragility curves for deteriorating highway bridges based only on the limited …

Surface Roughness Prediction In End Milling Processes Considering The Vibration Of The Cutting Tool, Yubin Lee

Dissertations and Theses

Purpose: Machining is a manufacturing process for making the desired design with dimensional tolerance and surface roughness. Despite the development of engineering technology, predicting machined surface roughness is still challenging since there are various factors, such as material properties, tool material properties, the rigidity of the machine tool, and the use of coolant. In particular, tool vibration is the most critical factor since it makes it challenging to obtain the desired quality of the machined product by unintentionally making a tool move. Therefore, surface finish was explored in this study, considering cutting tool vibration under various axial depth-of-cuts and feed …

Design And Optimization With Quantum And Memristor Platforms, Yiwei Li

Dissertations and Theses

The complexity and diversity of modern computing challenges have made it difficult for traditional computers to efficiently handle tasks such as computer-aided design, design optimization, and combinatorial problems within a reasonable time frame. In applications such as bitcoin mining and robotic control, power consumption and circuit size are critical factors. To overcome these limitations, this dissertation examines alternative computing technologies such as quantum computers and hybrid memristive circuits. The research demonstrates that these technologies hold the potential to offer more efficient and effective solutions for particular problems, whether in terms of faster computation or reduced power consumption.

Comparing The Performance Of Different Machine Learning Models In The Evaluation Of Solder Joint Fatigue Life Under Thermal Cycling, Jason Scott Ross

Dissertations and Theses

Predicting the reliability of board-level solder joints is a challenging process for the designer because the fatigue life of solder is influenced by a large variety of design parameters and many nonlinear, coupled phenomena. Machine learning has shown promise as a way of predicting the fatigue life of board-level solder joints. In the present work, the performance of various machine learning models to predict the fatigue life of board-level solder joints is discussed. Experimental data from many different solder joint thermal fatigue tests are used to train the different machine learning models. A web-based database for storing, sharing, and uploading …

Development Of Advanced Germanium Detectors For Rare Event Physics, Sanjay Bhattarai

Dissertations and Theses

High Purity Germanium (HPGe) detectors are widely used in rare-event physics searches for dark matter, neutrinoless double-beta decay, and solar neutrinos. This dissertation fo- cuses on improving crystal quality by controlling the impurity concentration, dislocation density, and growth environment as well as developing advanced Ge detectors for various physics applications. The dissertation presents experimental investigations of electrical conduction mechanisms in p-type amorphous germanium (a-Ge), which is used as an elec- trical contact material in HPGe detectors. By measuring the surface leakage current from three high-purity planar Ge detectors, we determine the localization length and hopping parameters in a-Ge. The dissertation …

Battery Energy Storage Systems Applications And Deployment In Dense Urban Areas, Mohamed K. Kamaludeen

Dissertations and Theses

Energy Storage has emerged as an important focus of the U.S. federal government, which has established the goal of developing global leadership in energy storage and has a near-term focus on strengthening the supply chain, manufacturing, and funding streams available to achieve the overarching objectives. At the state level, similar efforts are underway in which policy objectives have set aggressive targets around energy storage deployment. New York State, through its landmark climate act “CLCPA” and subsequent Energy Storage roadmap 2.0, has set one of the most aggressive goals in the Country targeting 6,000MW of energy storage by 2030. While much …

Understanding Failure Mechanisms Using Multi-Scale Analyses To Improve The Performance Of Zinc Metal And Lithium-Ion Batteries, Brendan E. Hawkins

Dissertations and Theses

We are beginning a global transition away from the use of fossil fuels for our energy needs toward using renewable energy sources in order to mitigate the effects of climate change. One of the biggest challenges to this transition is that, unlike fossil fuels, renewable energy systems have inherent intermittency and require supporting energy storage systems to enable reliable power distribution and electrified transportation. Rechargeable batteries are an attractive energy storage option because of their high energy efficiency, versatility, modularity, and ease of use. Lithium-ion batteries (LIBs) have dominated the rechargeable battery market for portable electronics for the past two …

Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha

Dissertations and Theses

This dissertation delves into the innovative application of mesoporous silica nanoparticles (MSNs) for targeted drug delivery in colorectal cancer (CRC), one of the most prevalent and deadly forms of cancer worldwide. The initial focus of the research is on developing enzyme-responsive MSNs loaded with veratridine (VTD), an alkaloid derived from natural sources that demonstrates potent anticancer activity. The nanoparticles have been engineered to deliver VTD selectively to CRC cells, releasing the payload upon being exposed to specific enzymes primarily secreted by these cells. This strategy has dual advantages of amplifying the anticancer effects while minimizing potential side effects on healthy …

Ultra-High Field Mri Methods For Precise Anatomical And Spectroscopic Measurements In The Brain And Application To Neurological And Neuropsychiatric Diseases, Judy Alper

Dissertations and Theses

Neurological and neuropsychiatric diseases and disorders are a major burden on society, impairing the health and functioning of millions of people every year. There is a need to define the biological bases of these diseases and identify potential biomarkers to improve diagnosis, monitoring, and treatment efficacy across multiple diseases.

Magnetic resonance imaging (MRI) is a noninvasive imaging technique which facilitates detection of brain lesions and visualization of the brain overall. However, limitations in contrast and resolution at clinical field strengths may hinder investigation of the underlying biological mechanisms of these diseases. Ultra-high field MRI scanners, such as those at 7-Tesla, …

Measurement Of Fluid Movement Throughout The Brain Via Multiple Magnetic Resonance Imaging Techniques During High-Definition Transcranial Direct Current Stimulation, Jack W. Beaty Mr

Dissertations and Theses

Transcranial Direct Current Stimulation (tDCS) is a non-invasive method of neuromodulation with applications in neuroscience, clinical care, and biomedical engineering. tDCS has been well established as a safe method of applying low amplitude current between two or more electrodes to alter excitation thresholds and neuroplasticity. Recently, in-vitro and clinical studies have suggested that DC stimulation can induce a transient, polarity-specific, effect of increased water exchange across the blood-brain barrier (BBB). The electroosmotic effect, the proposed phenomenon driving water exchange, is a biophysical response of charged ions moving across an oppositely-charged surface, i.e., the tight junction, when subjected to an electric …

Examining Elementary Teachers’ Self-Efficacy To Teach Engineering: The Impact Of Project Lead The Way Launch Professional Development, Branden Robert Hoefert

Dissertations and Theses

Today’s elementary teachers are expected to teach the engineering practices included in the National Research Council’s Framework for K-12 Science Education and the Next Generation Science Standards. Recent studies have indicated that teachers are less self-efficacious in teaching engineering than in other subject areas. Project Lead the Way (PLTW) is a nonprofit organization that offers pre-K–12th grade curricula and teacher training focused on three pathways: engineering, computer science, and biomedical science. Due to the COVID-19 pandemic, PLTW transitioned its teacher trainings to a virtual modality. At the time of this study, most of PLTW’s teacher training remained virtual or hybrid. …

Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew

Dissertations and Theses

A Modular Multilevel Converter (MMC) is an attractive candidate in high power conversion due to its modularity and scalability. The energy storage element, namely the module capacitance in the MMC submodule circuit, is typically large and when scaled to convert high power, requires very bulky module capacitors. In addition to deteriorating the power density, the design necessitates the use of electrolytic capacitors, which further affects the overall converter efficiency and reliability. This research presents an MMC submodule topology and the accompanying modulation approach that reduces the submodule capacitance requirements significantly compared to conventional MMC topology (few micro-farads versus several milli-farads). …

Cloud Container Security’ Next Move, Vishakha Sadhwani

Dissertations and Theses

In the last few years, it is apparent to cybersecurity experts everywhere that the proverbial container tech genie is out of the bottle, and has been widely embraced across multiple organizations. To achieve the flexibility of building and deploying applications anywhere and everywhere, cloud native environments have gained great momentum and made the development lifecycle simpler than ever. However, container environments brings with them a range of cybersecurity issues that includes images, containers, hosts, runtimes, registries, and orchestration platforms, which needs the necessity to focus on investing in securing your container stack.

According to this report[1], released by cloud-native …

An Experimental Study Of Norton And Thule Cooking Pot Performance, Caelie Marshall Butler

Dissertations and Theses

Ceramic technology was adopted by hunter-gatherers of the Paleo-Inuit Norton tradition in the Western Arctic between 2800 and 2500 years B.P., corresponding with an increase in the use of aquatic resources. Pottery production and use continued until approximately 1,500 BP, and resumed during the Neo-Inuit Birnirk and Thule periods, approximately 1,350 years BP. The technical characteristics of Norton and Thule ceramics suggest they performed differently when used for cooking, with Norton ceramics best suited for cooking using direct or suspended heat, and Thule ceramics best suited for indirect heat. Prior experimental archaeological research has focused on Thule ceramics, with limited …