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2020

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Articles 6871 - 6900 of 10642

Full-Text Articles in Engineering

Efficient Design Optimization Methodology For Manufacturable Variable Stiffness Laminated Composite Structures, Mazen Albazzan Apr 2020

Efficient Design Optimization Methodology For Manufacturable Variable Stiffness Laminated Composite Structures, Mazen Albazzan

Theses and Dissertations

Because of their superior mechanical and environmental properties compared to traditional metals, fiber-reinforced composite materials have earned a widespread acceptance for different structural applications. The tailoring potential of composites to achieve high specific stiffness and strength has promoted them as promising candidates for constructing lightweight structures. From that aspect, designers have tackled the problem of designing composite laminates, which is inherently challenging due to the presence of non-linear, non-convex, and multi-dimensional optimization problems with discrete and continuous design variables. However, despite their increased usage, the possible improvements that can be achieved by composite laminates have not been fully exploited. With …


Channel Modeling And Tropospheric Effects On Millimeter Wave Communications For Aviation Applications, Jinwen Liu Apr 2020

Channel Modeling And Tropospheric Effects On Millimeter Wave Communications For Aviation Applications, Jinwen Liu

Theses and Dissertations

Next generation communication systems will be designed to be faster, more secure and easier to connect with than current systems. Along with the concept of internet of things (IoT), many more devices will be required to communicate with each other. In the case of aeronautical vehicles and systems, in addition to current navigation and surveillance systems, more data links will be required for multiple applications, such as photography, inspections, and entertainment. Current aviation frequency bands will likely be unable to support all proposed services. Apart from air-to-ground (AG) communication links, airport surface terrestrial links and satellite-to-air links (SA) are also …


Influence Of Dynamic Multiaxial Transverse Loading On Ultrahigh Molecular Weight Polyethylene Single Fiber Failure, Frank David Thomas Apr 2020

Influence Of Dynamic Multiaxial Transverse Loading On Ultrahigh Molecular Weight Polyethylene Single Fiber Failure, Frank David Thomas

Theses and Dissertations

High performance fibers such as ultrahigh molecular weight polyethylene (UHMWPE) are often used for ballistic impact applications in the form of textile fabrics and composite laminates. In order to predict the ballistic performance of such materials, single-fiber experiments are performed to quantify the material behavior at smaller length scales, which can be applied to larger length scales as a result. Failure of UHMWPE is well understood as a function of simple tension at low and high strain rates, as well as under various multiaxial loading states. However, experimental characterization of single UHMWPE fibers under transverse loading at high strain rates …


Design Of Bio-Inspired Multifrequency Acoustic Sensors And Metamaterial Energy Harvesting Smart Structures, Mohammadsadegh Saadatzi Apr 2020

Design Of Bio-Inspired Multifrequency Acoustic Sensors And Metamaterial Energy Harvesting Smart Structures, Mohammadsadegh Saadatzi

Theses and Dissertations

Due to the limited availability and high depletion rates of nonrenewable sources of energy as well as environmental concerns, the scientific community has started to explore many alternative clean sources of energies. It is identified that civil, mechanical and Aerospace structures are always subjected to acoustic noises and vibration which could potentially be used as renewable source of energy. Roads and Industrial noise barriers are used inside industrial facilities alongside the walls, around construction pillars, nearby machinery and other equipment to separate quite work zones, protect walls, deliver extra safety and precautions while diminish sound and vibrational pressure. We hypothesized …


The Development Of Polymer Constructs For Adipose Tissue Engineering Applications, Kendall Murphy Apr 2020

The Development Of Polymer Constructs For Adipose Tissue Engineering Applications, Kendall Murphy

Theses and Dissertations

The adipose tissue functions as the body’s main energy reservoir and plays a central role in maintaining whole body energy homeostasis. The ability to modulate this tissue’s inherent endocrine and metabolic functions has promising implications in treating disease associated with adipose tissue dysfunction. This work revolves around two diseases where adipose tissue inflammation and metabolic dysfunction drive the disease, obesity and cachexia. Both diseases impact a significant population of U.S. adults and substantially reduce patient quality of life.

In this study, we first demonstrate the use of novel therapeutic platforms engineered to specifically target adipose tissue inflammation and lipid catabolism …


Nitric Oxide Expression With Age And Diet In The Arterial Wall Of Apoe Knockout Mice, Kara Cooper Apr 2020

Nitric Oxide Expression With Age And Diet In The Arterial Wall Of Apoe Knockout Mice, Kara Cooper

Theses and Dissertations

Background: Hypertension is a dangerous condition that precedes many cardiovascular events including myocardial infarction, stroke, transient cerebral ischemic attack and symptomatic aortoiliac occlusive disease. While it is universally accepted that arteries stiffen with age, the physiological reason for this is debated. In a previous study, by Dr. Shana Roach Watson it was shown that collagen fibers re-orient themselves in a circumferential direction, resulting in increased arterial stiffness. The study hypothesized that this collagen remodeling could be a result of decreased nitric oxide production.

Methods: This study measured nitric oxide in two different ways, indirectly via Immunoperoxidase staining for eNOS and …


Optimization Study Of An Image Classification Deep Neural Network, Rose Ault Apr 2020

Optimization Study Of An Image Classification Deep Neural Network, Rose Ault

Honors Projects

Machine Learning is an important and growing field within Artificial Intelligence. It is particularly useful in situations where developing an algorithm to perform the task in a conventional way would be extremely difficult. Instead of being programmed specifically to complete a task, a program embodies a trained model that can recognize patterns present in given example data, and is able use that model to make predictions on future data. Neural networks are a prominent example of machine learning models used for this purpose. Neural networks are models that are based on how brains work, with massive numbers of connected processing …


High-Speed And Low-Power Techniques For Successive-Approximation-Register Analog-To-Digital Converters, Eric Lee Swindlehurst Apr 2020

High-Speed And Low-Power Techniques For Successive-Approximation-Register Analog-To-Digital Converters, Eric Lee Swindlehurst

Theses and Dissertations

Broadband wireless communication systems demand power-efficient analog-to-digital converters (ADCs) in the GHz and medium resolution regime. While high-speed architectures such as the flash and pipelined ADCs are capable of GHz operations, their high-power consumption reduces their attractiveness for mobile applications. On the other hand, the successive-approximation-register (SAR) ADC has an excellent power efficiency, but its slow speed has traditionally limited it to MHz applications. This dissertation puts forth several novel techniques to significantly increase the speed and power efficiency of the SAR architecture and demonstrates them in a low-power 10-GHz SAR ADC suitable for broadband wireless communications. The proposed 8-bit, …


Contributions To The Theory And Application Of Multiple Model Estimation, Alia R. Strandt Apr 2020

Contributions To The Theory And Application Of Multiple Model Estimation, Alia R. Strandt

Dissertations (1934 -)

Multiple model estimation is a versatile technique that has been applied in a large variety of adaptive estimation problems. In this technique, several estimators, each designed around a possible model of the system, are used in parallel, and the estimator that most closely models the true system is determined using Bayes’ Rule. In this dissertation, convergence properties of the multiple model estimation algorithm are investigated, including a proof of convergence and factors that influence convergence time. In addition, the multiple model estimation algorithm is applied in two parameter estimation problems.The first half of the dissertation focuses on properties of the …


Reaching Performance In Heathy Individuals And Stroke Survivors Improves After Practice With Vibrotactile State Feedback, Valay A. Shah Apr 2020

Reaching Performance In Heathy Individuals And Stroke Survivors Improves After Practice With Vibrotactile State Feedback, Valay A. Shah

Dissertations (1934 -)

Stroke causes deficits of cognition, motor, and/or somatosensory functions. These deficits degrade the capability to perform activities of daily living (ADLs). Many research investigations have focused on mitigating the motor deficits of stroke through motor rehabilitation. However, somatosensory deficits are common and may contribute importantly to impairments in the control of functional arm movement. This dissertation advances the goal of promoting functional motor recovery after stroke by investigating the use of a vibrotactile feedback (VTF) body-machine interface (BMI). The VTF BMI is intended to improve control of the contralesional arm of stroke survivors by delivering supplemental limb-state feedback to the …


Patient-Specific Modeling Of Altered Coronary Artery Hemodynamics To Predict Morbidity In Patients With Anomalous Origin Of A Coronary Artery, Atefeh Razavi Apr 2020

Patient-Specific Modeling Of Altered Coronary Artery Hemodynamics To Predict Morbidity In Patients With Anomalous Origin Of A Coronary Artery, Atefeh Razavi

Dissertations (1934 -)

Anomalous aortic origin of a coronary artery (AAOCA) is a condition where a coronary artery arises from the opposite aortic sinus, often with acute angle of origin (AO). AAOCA is associated with ischemia.1 This is especially concerning when the anomalous coronary artery takes an intramural course within the aortic wall, creating the potential for distortion or compression. Unroofing surgery replaces a restrictive ostium and intramural segment with a large ostium from the appropriate sinus and aims to create a less acute AO. Although these anatomical features may alter coronary artery blood flow patterns, hemodynamic indices such as time averaged wall …


Eeg Characterization Of Sensorimotor Networks: Implications In Stroke, Dylan Blake Snyder Apr 2020

Eeg Characterization Of Sensorimotor Networks: Implications In Stroke, Dylan Blake Snyder

Dissertations (1934 -)

The purpose of this dissertation was to use electroencephalography (EEG) to characterize sensorimotor networks and examine the effects of stroke on sensorimotor networks. Sensorimotor networks play an essential role in completion of everyday tasks, and when damaged, as in stroke survivors, the successful completion of seemingly simple motor tasks becomes fantasy. When sensorimotor networks are impaired as a result of stroke, varying degrees of sensorimotor deficits emerge, most often including loss of sensation and difficulty generating upper extremity movements. Although sensory therapies, such as the application of tendon vibration, have been shown to reduce the sensorimotor deficits after stroke, the …


Characterization Of Neuroimage Coupling Between Eeg And Fmri Using Within-Subject Joint Independent Component Analysis, Nicholas Heugel Apr 2020

Characterization Of Neuroimage Coupling Between Eeg And Fmri Using Within-Subject Joint Independent Component Analysis, Nicholas Heugel

Dissertations (1934 -)

The purpose of this dissertation was to apply joint independent component analysis (jICA) to electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to characterize the neuroimage coupling between the two modalities. EEG and fMRI are complimentary imaging techniques which have been used in conjunction to investigate neural activity. Understanding how these two imaging modalities relate to each other not only enables better multimodal analysis, but also has clinical implications as well. In particular, Alzheimer’s, Parkinson’s, hypertension, and ischemic stroke are all known to impact the cerebral blood flow, and by extension alter the relationship between EEG and fMRI. By characterizing …


Probabilistic Framework For Balancing Smart Grid's Performance Enhancement And Resilience To Cyber Threat, Rezoan Ahmed Shuvro Apr 2020

Probabilistic Framework For Balancing Smart Grid's Performance Enhancement And Resilience To Cyber Threat, Rezoan Ahmed Shuvro

Dissertations (1934 -)

Critical infrastructures such as smart grids rely heavily on the seamless interaction between the grid subcomponents, i.e., the communication networks which transfers information from and to the grid, and the human operators/AI agents for taking necessary control actions. Smart grids are prone to cascading failures, which trigger from a few initial the tripping of a few transmission lines or generators, creating a ripple effect in the entire network, which may, in turn, lead to a total blackout. Having additional information through the communication network increases the probability of taking better control actions (e.g., effective load shedding and other protection mechanisms), …


Evaluating Crowdsourcing As A Vmt Reduction Tool To Support Smart Cities Initiatives, Shailesh Chandra, Rutviz Vyas, Ravi Mazin Apr 2020

Evaluating Crowdsourcing As A Vmt Reduction Tool To Support Smart Cities Initiatives, Shailesh Chandra, Rutviz Vyas, Ravi Mazin

Mineta Transportation Institute

Vehicle miles traveled (VMT) is an indicator of vehicular emissions, which impacts climate change. Various stakeholders aim at reducing VMT to cause reductions in emissions. This research explores the use of crowdsourcing in supporting the efforts of the stakeholders in reducing VMT among college students at California State University Long Beach. Crowdsourcing is emerging as a very promising tool in finding solutions to problems otherwise impossible to solve without a collective human intelligence. A smartphone application is developed to collect travel data and behavior of 55 college students as participants. The behavior is tracked after providing advance information on parking …


Evaluation Of Coordinated Ramp Metering (Crm) Implemented By Caltrans, Amir Molan, Nivedha Murugesan, Alireza Shams, Cristina Tortora, Faridur Rahman, Jacky Loh, Anurag Pande Apr 2020

Evaluation Of Coordinated Ramp Metering (Crm) Implemented By Caltrans, Amir Molan, Nivedha Murugesan, Alireza Shams, Cristina Tortora, Faridur Rahman, Jacky Loh, Anurag Pande

Mineta Transportation Institute

Coordinated ramp metering (CRM) is a critical component of smart freeway corridors that rely on real-time traffic data from ramps and freeway mainline to improve decision-making by the motorists and Traffic Management Center (TMC) personnel. CRM uses an algorithm that considers real-time traffic volumes on freeway mainline and ramps and then adjusts the metering rates on the ramps accordingly for optimal flow along the entire corridor. Improving capacity through smart corridors is less costly and easier to deploy than freeway widening due to high costs associated with right-of-way acquisition and construction. Nevertheless, conversion to smart corridors still represents a sizable …


Local Government Policy And Planning For Unmanned Aerial Systems, Tyler Spence, Francesca Favaro, Kally Yeung Apr 2020

Local Government Policy And Planning For Unmanned Aerial Systems, Tyler Spence, Francesca Favaro, Kally Yeung

Mineta Transportation Institute

This research identifies key state and local government stakeholders in California for drone policy creation and implementation, and describes their perceptions and understanding of drone policy. The investigation assessed stakeholders’ positions, interests, and influence on issues, with the goal of providing potential policy input to achieve successful drone integration in urban environments and within the national airspace of the United States. The research examined regulatory priorities through the use of a two-tiered Stakeholder Analysis Process. The first tier consisted of a detailed survey sent out to over 450 local agencies and jurisdictions in California. The second tier consisted of an …


The Geographic Disparities In Transportation-Related Physical Activity In The United States: An Analysis Of The 2017 Nhts Data, Hongwei Dong Apr 2020

The Geographic Disparities In Transportation-Related Physical Activity In The United States: An Analysis Of The 2017 Nhts Data, Hongwei Dong

Mineta Transportation Institute

Research on the relationship between urbanicity and physical activity yielded mixed results despite many studies consistently showing that residents tended to undertake more transportation-related physical activity in a more urban environment. This study analyzed the 2017 NHTS data to examine the geographic disparities in physical activity, particularly transportation-related physical activity in the United States. Our analysis suggests the relationship between urbanicity and physical activity demonstrates a flat U-shape in graphed data. Residents are more physically active when they live in the areas from the two ends of the urbanization spectrum: inner cities and inner suburbs of large metropolitan areas and …


Securing The Emerging Technologies Of Autonomous And Connected Vehicles, Shahab Tayeb, Matin Pirouz Apr 2020

Securing The Emerging Technologies Of Autonomous And Connected Vehicles, Shahab Tayeb, Matin Pirouz

Mineta Transportation Institute

The Internet of Vehicles (IoV) aims to establish a network of autonomous and connected vehicles that communicate with one another through facilitation led by road-side units (RSUs) and a central trust authority (TA). Messages must be efficiently and securely disseminated to conserve resources and preserve network security. Currently, research in this area lacks consensus about security schemes and methods of disseminating messages. Furthermore, a current deficiency of information regarding resource optimization prevents further efficient development of this network. This paper takes an interdisciplinary approach to these issues by merging both cybersecurity and data science to optimize and secure the network. …


Climate Change Analysis And Stream Restoration In The Upper Truckee River Basin, Nicholas Szigeti, Christian Raslowsky Apr 2020

Climate Change Analysis And Stream Restoration In The Upper Truckee River Basin, Nicholas Szigeti, Christian Raslowsky

Civil, Environmental and Sustainable Engineering Senior Theses

The Upper Truckee River (UTR) Basin is the largest watershed that drains into Lake Tahoe in the Sierra Nevada Mountain Range. Channelization and degradation of historic floodplains have caused fine sediment particles to erode from river banks and reduce the clarity of Lake Tahoe. In addition, as climate change worsens, it is expected that the hydrology of the region will not adhere to historical trends. To help solve these issues a climate analysis was conducted for a watershed near the UTR using four global climate models (due to lack of data availability and resources), and a scoured reach of the …


Evaporation Rate From Free Water Surface, Safa M. Aldarabseh Apr 2020

Evaporation Rate From Free Water Surface, Safa M. Aldarabseh

Dissertations

This work aims to perform an experiment in the laboratory and investigate the effect of the wave steepness, airflow velocity, air relative humidity, air temperature, and water surface temperature on the evaporation rate from still and wavy water surface. In this investigation, the experimental results are used to quantify an evaporation rate from a still and wavy water surface under different convection regimes that are free, mixed, and forced convection under turbulent airflow conditions. Empirical correlations are also derived using the experimental results based on modified Dalton’s law and Similarity method (analogy between mass and heat transfer equation). In this …


Design Of Cultural Preservation Center For The Nez Perce Tribe, Catherine Moore, Carolina Avelar, Rodolfo Leon Apr 2020

Design Of Cultural Preservation Center For The Nez Perce Tribe, Catherine Moore, Carolina Avelar, Rodolfo Leon

Civil, Environmental and Sustainable Engineering Senior Theses

The Cultural Preservation Program of the Nez Perce tribe centered in Lapwai , Idaho is growing and in need of additional space to house its many programs. Due to this need , the team considered several alternative solutions to provide necessary space for the Cultural Resource Program to continue growing , while maintaining the several programs it currently oversees. Alternative designs considered include the renovation of existing buildings near the current Cultural Resource Program , the use of historical structures within the reservation and the building of a new structure or structures to house the Cultural Resource Program. The final …


Efficient Hardware/Software Partitioning Techniques For A Cloud-Scale Cpu-Fpga Platform, Samah Ziyad Rahamneh Apr 2020

Efficient Hardware/Software Partitioning Techniques For A Cloud-Scale Cpu-Fpga Platform, Samah Ziyad Rahamneh

Dissertations

The diversity of workload characteristics has stimulated the deployment of heterogeneous architectures to accommodate workloads’ requirements disparity in cloud data centers. In heterogeneous computing, co-processors are utilized to support Central Processing Units (CPUs) in fulfilling workload demands. Field Programmable Gate Arrays (FPGAs) have advantages over other accelerators because of their power, performance and re-configurability benefits. In order to achieve the most benefit of a heterogeneous platform, efficient partitioning of workload between the CPU and the FPGA is a crucial demand.

This dissertation first presents a design and implementation of cooperative CPU-FPGA execution techniques, which include code and data partitioning, of …


Hester Gardens - A Lifemoves Temporary Interim-Housing Facility, Jeffrey Meier, Megan Sauter, Jenna Tran, Taylor Klauser Apr 2020

Hester Gardens - A Lifemoves Temporary Interim-Housing Facility, Jeffrey Meier, Megan Sauter, Jenna Tran, Taylor Klauser

Civil, Environmental and Sustainable Engineering Senior Theses

LifeMoves, an organization that provides interim housing and supportive services to families and individuals experiencing homelessness, recently purchased 0.35 acres of land, located at 1759 Hester Avenue, San Jose, CA 95128. LifeMoves has challenged the design team to provide preliminary building layouts, a structural alternative analysis, construction management plans, and general civil plans for a multi-story, family-friendly, interim housing facility, which has been named Hester Gardens. The design team considered both steel, a traditional building material, and shipping containers, a sustainable alternative building material, for this project. Each alternative included a structural design and analysis, as well as a cost …


Incorporating A Reverse Logistics Scheme In A Vehicle Routing Problem With Cross-Docking Network: A Modelling Approach, Audrey Tedja Widjaja, Aldy Gunawan, Panca Jodiawan, Vincent F. Yu Apr 2020

Incorporating A Reverse Logistics Scheme In A Vehicle Routing Problem With Cross-Docking Network: A Modelling Approach, Audrey Tedja Widjaja, Aldy Gunawan, Panca Jodiawan, Vincent F. Yu

Research Collection School Of Computing and Information Systems

Reverse logistics has been implemented by various companies because of its ability to gain more profit and maintain the competitiveness of the company. However, extensive studies on the vehicle routing problem with cross-docking (VRPCD) only considered the forward flow instead of the reverse flow. Motivated by the ability of a VRPCD network to minimize the distribution cost in the forward flow, this research incorporates the reverse logistics scheme in a VRPCD network, namely the VRP with reverse cross-docking (VRP-RCD). We propose a VRP-RCD mathematical model for a four-level supply chain network that involves suppliers, cross-dock, customers, and outlets. The main …


How To And How Much? Teaching Ethics In An Interaction Design Course, Bimlesh Wadhwa, Eng Lieh Ouh, Benjamin Gan Apr 2020

How To And How Much? Teaching Ethics In An Interaction Design Course, Bimlesh Wadhwa, Eng Lieh Ouh, Benjamin Gan

Research Collection School Of Computing and Information Systems

How much is sufficient and how should one teach ethics in an Interaction Design curriculum in undergraduate computing program has been a point of dilemma for many HCI educators. We conducted a preliminary study using a mixed method to gather perception on ethics in our interaction design courses at two of the leading Singapore Universities. We answer three research questions specific to an undergraduate HCI course: Is there a need for ethics? Is there sufficient ethics coverage? and how to teach ethics? We surveyed 140 students and interviewed six teachers in two Singapore Universities. Our findings suggest that 92% of …


Validation Risk Across Hierarchical Models, John B. Young Apr 2020

Validation Risk Across Hierarchical Models, John B. Young

Computational Modeling & Simulation Engineering Theses & Dissertations

Modeling and simulation are applied in a great many methods across a variety of topics. Model developers and users alike have a professional duty to understand the complexities of the tools and methods they are used. Oftentimes, models that have been independently constructed and executed are used to inform one another for an analytic purpose and the compatibility of the models is not always addressed. In the literature, great attention has been paid to model validation. When using models constructively with one another, analysts must understand the bounds of model validity and ensure that the combination of models does not …


Engineering Management Competencies: A Framework For Present And Future Engineering Environments, Christopher Vaughn Barrett Apr 2020

Engineering Management Competencies: A Framework For Present And Future Engineering Environments, Christopher Vaughn Barrett

Engineering Management & Systems Engineering Theses & Dissertations

Managing and directing engineering requires engineering management competencies. Although perspectives may differ concerning competencies for engineering management, identifying competencies can direct and improve management. The purpose of this research is to develop a framework of competencies for engineering managers using an inductive research design. Development of this engineering management competency framework involves an exploration of three primary research questions. The first question is ‘What are the current competencies for engineering managers?’ The response to this question provides a basis for the current state of competencies for engineering managers. The second research question, ‘What are future engineering management competencies based on …


A Post-Impact Behavior Of Platelet-Based Composites Produced By Compression Molding, Christopher Eugene Ervin Volle Apr 2020

A Post-Impact Behavior Of Platelet-Based Composites Produced By Compression Molding, Christopher Eugene Ervin Volle

Mechanical & Aerospace Engineering Theses & Dissertations

Prepreg-based Platelet Molded Compounds (PPMCs) are quickly becoming a widely used method for creating structural components in the aerospace and automotive industries. The discontinuous nature of the platelets used allow good formability of both complex and basic structural components; from seats on commercial airplanes to outer panels of vehicles.

This thesis will look at an important research question of these composites: how PPMCs behave under dynamic loading, e.g. impact and post-impact behavior. Impact is analyzed using recorded force and velocity data to find the absorbed energy. Digital image correlation is used with compression after impact testing to study the propagation …


A Study Of The Aeroacoustics Of Swept Propellers For Small Unmanned Aerial Vehicles, Arthur David Wiedemann Apr 2020

A Study Of The Aeroacoustics Of Swept Propellers For Small Unmanned Aerial Vehicles, Arthur David Wiedemann

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, small unmanned aerial vehicles (UAVs) have increased in availability and use in both public and commercial sectors. This increased use of small UAVs or “drones” has the unfortunate consequence of introducing excessive noise into communities where they operate. Implementation of noise reduction methods is necessary if we wish to see expanded use of drones in public areas. With electric propulsion, the primary source of noise is the rotor/propeller used in contemporary multi-rotor configurations. In this thesis, the aerodynamics and acoustic behavior of various swept propellers is examined with computational and experimental methods.

A family of propeller geometries …