Engineering Commons^™

Electrical Machines For Harsh Environments, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

There have been several megatrends over the past several years that have been driving research activities in the area of electrical machines and drives. These include transportation electrification (land vehicles, aerospace, ships, locomotives), expanded role of renewables (wind, solar, wave…etc.), and smart grid among others. One of those megatrends that continues to become more critical is electrical machines for harsh environments. In many applications, production has been moved to remote locations and harsh environments. These include subsea oil exploration, sour/acid gas compression, downhole and geothermal pumps, underground mining, and aerospace applications. This paper will provide an overview of electrical machine …

Liquidated Damages: An Analysis Of Their Use And Effectiveness, Alfredo N. Aragon

Construction Management

A construction company’s success and/or failure is dependent upon project completion with respect to time and budget. Failure to meet the contract completion date results in a loss of profit for owners and contractors alike. In order to help mitigate project delays, liquidated damage clauses have been included into construction contracts. Incorporating provisions within the construction contracts in the form of liquidated damages aims to help shift the financial burden when there is a failure to meet contractual obligations, hopefully offering quick compensation for delays. Unlike general or actual damages, liquidated damages are pre-defined and agreed upon prior to entering …

Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research effort, the authors claim that possessing technical knowledge is not a sufficient asset to establish a learning environment that renders engagement with engineering students during lecture sessions, but rather the integration of various communication strategies that support students’ academic development. Research has noted that classroom context and conditions impact the degree of student learning and engagement and are further enhanced when students feel comfortable communicating with the instructor and with their peers. If such acquaintance is nonexistent, student participation may be stifled and limited despite the technical concerns arising during lecture sessions. Thus, it is imperative for …

Evaluating Creative Choice In K-12 Computer Science Curriculum, Kirsten L. Mork

Master's Theses

Computer Science is an increasingly important topic in K-12 education. Ever since the "computing crisis" of the early 2000s, where enrollment in CS dropped by over half in a five year span, increasing research has gone into improving and broadening enrollment in CS courses. Research shows the importance of introducing CS at a young age and the need for more exposure for younger children and young adults alike in order to work towards equity in the field. While there are many reasons for disinterest in CS courses, studies found one reason young adults do not want to study CS is …

Cmos Design Of An 8-Bit 1ms/S Successive Approximation Register Adc, Ameya Vivekanand Ganguli

Master's Theses

Rapid evolution of integrated circuit technologies has paved a way to develop smaller and energy efficient biomedical devices which has put stringent requirements on data acquisition systems. These implantable devices are compact and have a very small footprint. Once implanted these devices need to rely on non-rechargeable batteries to sustain a life span of up to 10 years. Analog-to-digital converters (ADCs) are key components in these power limited systems. Therefore, development of ADCs with medium resolution (8-10 bits) and sampling rate (1 MHz) have been of great importance.

This thesis presents an 8-bit successive approximation register (SAR) ADC incorporating an …

Advanced Concrete Course For Cal Poly Construction Management Department, Dante N. Feliciano

Construction Management

This senior project provides a solution to the Construction Management Department at Cal Poly, San Luis Obispo whose curriculum lacks an individual Concrete course. With Concrete being one of the most used building material worldwide, this course will help immensely. The goal of this project is to fill the gap with an Advanced Concrete Course that is prepared and ready to be introduced to future students. The course has an emphasis on outside research learning – where the student gets to become the instructor. Carefully thought out and executed lecture materials are included in the course. Lecture slides give background …

Development Of A Topics Course For Construction Management, William Harrison Wygal

Construction Management

The Cal Poly Construction Management program has been proven to produce some of the most prepared graduates heading into new careers in every facet of the construction industry. Speaking with faculty member Tom Kommer, we have concluded that there is a need for an increased focus on construction risk management within the curriculum. In order to develop a course which would suitably educate Cal Poly Construction Management students in the topic of risk management, I performed a literary review during which I determined which risks are most prevalent within the construction industry and how firms in the construction industry manage …

Implementing Ipd Principles On Custom Residential Projects: Tools And Best Practices, Giuseppi K. Jenkins

Theses and Dissertations

The purpose of this research is to see how Integrated Project Delivery (IPD) principles and practices can be used on high end custom residential construction projects to increase the collaboration and efficiency of the project team. A case study was conducted on a custom home project to observe how and what IPD principles were used. Observations, interviews and a survey were used as part of that case study to gain insights. This research found that IPD principles and practices could be used on residential projects. In addition, the research found that those involved found the experience positive and beneficial to …

Robust Visual-Inertial Navigation And Control Of Fixed-Wing And Multirotor Aircraft, Jerel Bendt Nielsen

Theses and Dissertations

With the increased performance and reduced cost of cameras, the robotics community has taken great interest in estimation and control algorithms that fuse camera data with other sensor data.In response to this interest, this dissertation investigates the algorithms needed for robust guidance, navigation, and control of fixed-wing and multirotor aircraft applied to target estimation and circumnavigation.This work begins with the development of a method to estimate target position relative to static landmarks, deriving and using a state-of-the-art EKF that estimates static landmarks in its state.Following this estimator, improvements are made to a nonlinear observer solving part of the SLAM problem.These …

Cej Ankle Support Report, Christine Prothe, James Baldwin, Erik Espinoza

Biomedical Engineering

This document provides information about an ankle support device designed to allow for ankle dorsiflexion and plantar flexion. In this document the product’s specifications, objectives and expectations are outlined. Included in this document is background information, stage gate process, prototype design development and considerations, and qualification requirements.

House Calls Mobile Virtual Stethoscope, Abigail Lindquist, Abigael Donohue, Trey Nahhas

Biomedical Engineering

The purpose of this scope of work is to outline the progress of the Virtual Stethoscope design and development project as sponsored by House Calls Mobile. This device looks to provide accessible at-home care for patients all over the country through the mobile phone stethoscope attachment. With the virtual stethoscope technology, patients will be able to perform high-quality, in-home observation of heart, stomach, and lung sounds to be transmitted to a physician in real time. Eliminating the need to travel to a doctor’s office encourages patients to perform more regular checkups, increasing their likelihood potentially of life-saving early diagnoses. This …

Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki

Biomedical Engineering

This critical design report describes the product development of a prosthesis for use on sand. Quality of Life Plus (QL+), a national non-profit organization aimed to develop prostheses for veterans and people with disabilities, introduced this project and its accompanying challenger, Sgt. Brady, to Cal Poly’s Interdisciplinary Senior Project class in September 2018. After consulting with Sgt. Brady and QL+ and performing extensive research, the Sand Foot team defined customer requirements and engineering specifications to meet these requirements. Comfortability, durability, and sandproof were key customer requirements. Several conceptual models were brainstormed and a final design was selected based on the …

Poster: Life After Sports: Black Males Pursuing Engineering And Related Stem Fields, Leroy L. Long Iii, Robert A. Bennett Iii, Morris R. Council Iii, Mckenna James

Publications

This poster summarizes findings and offers recommendations from a research study involving Black males who majored in engineering or a related STEM field and played a collegiate sport. Specifically, the poster highlights ways in which the research participants were able to transition from playing sports to pursuing an engineering or related STEM career. For this particular poster, the presenters focused on the experiences of four Black men. Two of the Black men played college football at historically Black colleges and universities (HBCUs) in the Southeast. Two other Black men ran track at Division 2 (D2) predominantly White institutions (PWIs) in …

Simulation Of Human Balance Control Using An Inverted Pendulum Model, Joshua E. Caneer

Maseeh Summer Undergraduate Research Experience

The nervous system that human beings use to control balance is remarkably adaptable to a wide variety of environments and conditions. This neural system is likely a combination of many inputs and feedback control loops working together. The ability to emulate this system of balance could be of great value in understanding and developing solutions to proprioceptive disorders and other diseases that affect the human balance control system. Additionally, the process of emulating the human balance system may also have widespread applications to the locomotion capabilities of many types of robots, in both bipedal and non-bipedal configurations.

The goal of …

Empirical And Theoretical Analysis Of Solar Devices In Public Spaces, Justin Morgan Roberts

Theses and Dissertations

With the debate on global warming and climate change, renewable energy resources, such as solar energy, are being considered. If solar energy is to make a major utility contribution, it will need to be more ubiquitous in today’s society. The research described hereafter analyzes the use of Solar in Public Spaces (SPS). SPS is defined as solar energy used in the public domain to power electronics away from the electric grid. This research specifically examines the viability of integrating solar panels into existing surfaces to charge portable electronics. Viability is evaluated using three criteria: (1) user interaction, (2) technical feasibility, …

Replacement Rates Of Initially Hydrocarbon-Filled Microscopic Cavities With Water, Hans Christian Larson

Theses and Dissertations

Wetting behaviors influence many aspects of life and industry from consumer product goods to oil recovery to cosmetics. While the traditional solid-liquid-vapor (SLV) system has been studied for many years now, wetting transitions in the solid-liquid-liquid (SLL) system has remained relatively unexplored. The purpose of this work is to bring light to the wetting transition of the solid-liquid-liquid system and to understand the replacement rates of initially hydrocarbon-filled microscopic cavities with water and the factors affecting these rates. Factors studied were viscosity, density, diffusion related properties, and surface related properties in both hydrocarbon-saturated and hydrocarbon-non-saturated conditions. Cylindrical microscopic cavities were …

Phased Array Digital Beamforming Algorithms And Applications, David Moyle Marsh

Theses and Dissertations

With the expansion of unmanned aircraft system (UAS) technologies, there is a growing need for UAS Traffic Management (UTM) systems to promote safe operation and development. To be successful, these UTM systems must be able to detect and track multiple drones in the presence of clutter. This paper examines the implementation of different algorithms on a compact, X-band, frequency modulated continuous wave (FMCW) radar in an effort to enable more accurate detection and estimation of drones. Several algorithms were tested through post processing on actual radar data to determine their accuracy and usefulness for this system. A promising result was …

Toward Using Empirical Mode Decomposition To Identify Anomalies In Stream Flowdata And Correlations With Other Environmental Data, Saul Gallegos Ramirez

Theses and Dissertations

I applied empirical mode decomposition (EMD) and the Hilbert-Herbert transforms, as tools to analyze streamflow data. I used the EMD method to extract and analyze periodic processes and trends in several environmental datasets including daily stream flow, daily precipitation, and daily temperature on data from the watersheds of two rivers in the Upper Colorado River Basin, the Yampa and the Upper-Green rivers. I used these data to identify forcing functions governing streamflow. Forcing functions include environmental factors such as temperature and precipitation and anthropogenic factors such as dams or diversions. The Green and Yampa Rivers have similar headwaters, but the …

Electrochemical Fabrication Of Elastin-Containing Bi-Layered Scaffold For Vascular Tissue Engineering Applications, Thuy-Uyen Ky Nguyen

Theses and Dissertations

Lack of a viable vascular graft for the replacement of diseased small diameter blood vessels (< 4 mm) has encouraged the development of a self-repairing tissue engineered vascular graft (TEVG) as a promising alternative source. Although many different fabrication approaches have been devised to generate TEVGs using both natural and synthetic biomaterials, a functional TEVG that can serve as an effective replacement of diseased small-diameter blood vessels (< 4 mm) is still elusive mainly due to concerns associated with thrombosis and intimal hyperplasia. One approach to improve the clinical outcome of vascular grafts is to develop a 3D biomimetic scaffold that provides the essential physicochemical cues (i.e., compositional, topographical) to modulate cellular response (i.e., cell phenotype, endothelialization, de novo elastic matrix production) and thereby aid in tissue repair and remodeling. This approach entails the development of a novel 3D scaffold that provides an aligned collagen platform to guide smooth muscle cell (SMC) orientation

and insoluble elastic matrix (i.e., native form of elastin) to promote SMC contractility and thereby prevent overproliferation and hence alleviate concerns with intimal hyperplasia. In addition, the scaffold must comprise of a smooth luminal side to support the formation of a continuous endothelium that is essential to prevent thrombosis. Most existing biofabrication methodologies to generate vascular scaffolds (e.g., extrusion, electrospinning) have limited scope because of the inability to incorporate insoluble elastic matrix within the aligned collagen framework due to the disparity in the size …

Modeling Multirotor Aerodynamic Interactions Through The Vortex Particle Method, Eduardo Alvarez, Andrew Ning

Faculty Publications

Distributed electric propulsion and vertical take-off and landing has recently opened a new design space for urban air mobility. However, the use of multiple rotors operating in close proximity introduces complicated aerodynamic interactions that are not well understood, are not captured through conventional design tools, and need to be addressed in the conceptual design stage. This study investigates the accuracy of the viscous vortex particle method (VPM) in modeling rotor-on-rotor aerodynamic interactions in a side- by-side configuration as encountered in tilt-rotor, quadrotor, and distributed propulsion aircraft. The VPM approach has the potential to enable the use of mid/high fidelity models …

Analysis Of Disengagements In Semi-Autonomous Vehicles: Drivers’ Takeover Performance And Operational Implications, Francesca M. Favaro, Sky Eurich, Syeda Rizvi, Shivangi Agarwal, Sumaid Mahmood, Nazanin Nader

Mineta Transportation Institute

This report analyzes the reactions of human drivers placed in simulated Autonomous Technology disengagement scenarios. The study was executed in a human-in-the-loop setting, within a high-fidelity integrated car simulator capable of handling both manual and autonomous driving. A population of 40 individuals was tested, with metrics for control takeover quantification given by: i) response times (considering inputs of steering, throttle, and braking); ii) vehicle drift from the lane centerline after takeover as well as overall (integral) drift over an S-turn curve compared to a baseline obtained in manual driving; and iii) accuracy metrics to quantify human factors associated with the …

Fatigue Performance Of Rc Beams Strengthened With Near Surface Mounted Cfrp Composites, Tamer Ghaith Mousa Eljufout

Dissertations

Bridges have a fundamental role in improving the effectiveness of highways and providing an expedient and express traffic system. Over time, Reinforced Concrete (RC) bridges degrade due to gradually increased traffic loads and environmental deteriorations. Subsequently, service loads might cause higher stresses in concrete and steel reinforcement than stresses considered in the design stage. This affects the structural performance of RC beams and leads to sudden fatigue failure. As such, there is an essential need for rehabilitation to avoid hazards and tragedies.

Carbon Fiber Reinforced Polymer (CFRP) composites are becoming widely used to strengthen RC bridges. Near Surface Mounted (NSM) …

Blind Separation For Intermittent Sources Via Sparse Dictionary Learning, Annan Dong

Dissertations

Radio frequency sources are observed at a fusion center via sensor measurements made over slow flat-fading channels. The number of sources may be larger than the number of sensors, but their activity is sparse and intermittent with bursty transmission patterns. To account for this, sources are modeled as hidden Markov models with known or unknown parameters. The problem of blind source estimation in the absence of channel state information is tackled via a novel algorithm, consisting of a dictionary learning (DL) stage and a per-source stochastic filtering (PSF) stage. The two stages work in tandem, with the latter operating on …

Probabilistic Spiking Neural Networks : Supervised, Unsupervised And Adversarial Trainings, Alireza Bagheri

Dissertations

Spiking Neural Networks (SNNs), or third-generation neural networks, are networks of computation units, called neurons, in which each neuron with internal analogue dynamics receives as input and produces as output spiking, that is, binary sparse, signals. In contrast, second-generation neural networks, termed as Artificial Neural Networks (ANNs), rely on simple static non-linear neurons that are known to be energy-intensive, hindering their implementations on energy-limited processors such as mobile devices. The sparse event-based characteristics of SNNs for information transmission and encoding have made them more feasible for highly energy-efficient neuromorphic computing architectures. The most existing training algorithms for SNNs are based …

Electrochemically Reactive Membranes For Efficient Biomass Recovery, Pollutant Degradation And Commercialization, Likun Hua

Dissertations

Micropollution in natural waters such as rivers and groundwater aquifers is a widespread problem that prevents these potentially potable sources from being used as drinking water. In the United States, approximately two-thirds of the over 1,200 most serious hazardous waste sites in the nation are contaminated with trichloroethylene (TCE), a potentially carcinogenic compound. Other emerging and environmentally persistent organic micropollutants include polyromantic hydrocarbons (PAHs), organophosphate flame retardants, endocrine disrupting compounds (EDCs), pesticides, herbicides, pharmaceuticals and personal care products (PPCPs). Membrane filtration is one of the most efficient separation processes widely used for water treatment and pollutant removal. However, traditional membrane …

A Multimodal Approach To Investigate Brain Reorganization After Spinal Cord Injury Using Functional Magnetic Resonance Imaging And Functional Near-Infrared Spectroscopy, Keerthana Deepti Karunakaran

Dissertations

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating …

Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury

Dissertations

A new approach to improve the capacitance of supercapacitors (SC) is proposed in this study. A typical SC is composed of an anode and a cathode; a separator in between them assures an unintentional discharge of the capacitor. The study focuses on a family of structured separators, either electronically active or passive which are called gates. An active structured separator layer has been fabricated and analyzed. The structured separator has characteristics of electrical diode and is fabricated out of functionalized carbon nanotubes (CNT). Improvement of the overall capacitance of SC, equipped with either active or passive structured separators demonstrated a …

Minimizing Vehicular Traffic Via Optimized Land Use Development For A Sustainable And Equitable Future, Babu Veeregowda

Dissertations

Mixed-use developments and transit-oriented developments are becoming very common in urban areas in an effort to reduce sprawl. Numerous studies have shown that such programs would not be successful unless the mix of land uses and sizes is well-balanced and integrated with the surrounding neighborhood. Developers often ignore this aspect in favor of immediate financial gain and do not realize that there are sustainable financial benefits in land use optimization. In addition, professionals often work with limited logistics, resources, and technical knowledge and therefore struggle in setting goals and suggesting land uses that have less auto dependency based on travel …

Dual Modality Optical Coherence Tomography : Technology Development And Biomedical Applications, Farzana Rahmat Zaki

Dissertations

Optical coherence tomography (OCT) is a cross-sectional imaging modality that is widely used in clinical ophthalmology and interventional cardiology. It is highly promising for in situ characterization of tumor tissues. OCT has high spatial resolution and high imaging speed to assist clinical decision making in real-time.

OCT can be used in both structural imaging and mechanical characterization. Malignant tumor tissue alters morphology. Additionally, structural OCT imaging has limited tissue differentiation capability because of the complex and noisy nature of the OCT signal. Moreover, the contrast of structural OCT signal derived from tissue’s light scattering properties has little chemical specificity. Hence, …

High-Performance Learning Systems Using Low-Precision Nanoscale Devices, Nandakumar Sasidharan Rajalekshmi

Dissertations

Brain-inspired computation promises a paradigm shift in information processing, both in terms of its parallel processing architecture and the ability to learn to tackle problems deemed unsolvable by traditional algorithmic approaches. The computational capability of the human brain is believed to stem from an interconnected network of 100 billion compute nodes (neurons) that interact with each other through approximately 10¹⁵ adjustable memory junctions (synapses). The conductance of synapses is modifiable allowing the network to learn and perform various cognitive functions. Artificial neural networks inspired by this architecture have demonstrated even super-human performance in many complex tasks.

Computational systems based …