Engineering Commons^™

Simulating Electric Vehicle Short-Notice Wildfire Evacuation In California Rural Communities, Gudrun Derickson

Master's Theses

The transportation sector in California has begun a shift toward adopting Electric Vehicles (EVs) as a primary source of individual and corporate mobility. The US Government and the State of California are initiating public-sector financed charging station infrastructure to help in this change-over to EVs. Automobile companies and private enterprises are also heavily investing in Battery Electric Vehicle (BEV) infrastructure going forward. The state of California is subject to natural disasters such as Fire, Earthquakes, and periodic flooding. Increasing numbers of BEVs may add new challenges to mass evacuations that are often associated with natural disasters. This work focuses on …

Subnational Map Of Poverty Generated From Remote-Sensing Data In Africa: Using Machine Learning Models And Advanced Regression Methods For Poverty Estimation, Lionel N. Hanke

Master's Theses

According to the 2020 poverty estimates from the World Bank, it is estimated that 9.1% - 9.4% of the global population lived on less than $1.90 per day. It is estimated that the Covid-19 pandemic further aggravated the issue by pushing more than 1% of the global population below the international poverty line of $1.90 per day (WorldBank, 2020). To provide help and formulate effective measures, poverty needs to be located as exact as possible. For this purpose, it was investigated whether regression methods with aggregated remote-sensing data could be used to estimate poverty in Africa. Therefore, five distinct regression …

Minimizing Leakage In Thin Walled Structures Printed Through Selective Laser Melting, Andrew Spencer Yap

Master's Theses

In this project, the scan strategy of selective laser melting (SLM) for thin walled structures was investigated by changing laser parameters and tool path. Producing thin walled structures is difficult due to defects such as warpage and porosity. A layer on the SLM 125 consists of hatch volume, fill contours, and borders, however, for thin walls, hatch volume can become unavailable, resulting in a solely border/fill contour laser tool path.

Three central composite designs (CCD) were created to optimize the laser parameters of borders to minimize leakage rate and porosity. The two factors changed were border laser power and scanning …

Modeling And Solving The Outsourcing Risk Management Problem In Multi-Echelon Supply Chains, Arian A. Nahangi

Master's Theses

Worldwide globalization has made supply chains more vulnerable to risk factors, increasing the associated costs of outsourcing goods. Outsourcing is highly beneficial for any company that values building upon its core competencies, but the emergence of the COVID-19 pandemic and other crises have exposed significant vulnerabilities within supply chains. These disruptions forced a shift in the production of goods from outsourcing to domestic methods.

This paper considers a multi-echelon supply chain model with global and domestic raw material suppliers, manufacturing plants, warehouses, and markets. All levels within the supply chain network are evaluated from a holistic perspective, calculating a total …

Perishable Food Waste Reduction Through Technological Implementation At The Retail Level Of The Food Supply Chain, Cassandra Harriman

Master's Theses

Food waste has become a disaster of global proportion that the world can no longer turn a blind eye to. This paper aims to reduce food waste at the retail level of the food supply chain by recommending and quantifying the effects of current technology that can be implemented in traditional supermarkets. This research recommends that retailers implement electronic shelf labels in stores and employ dynamic pricing of perishable products, leading to reduction of food waste. No prior research had considered the primary goal of reducing food waste while preserving retailer profit through technological implementation. This paper quantifies the effects …

Understanding The Impact Of The Covid-19 Pandemic Within Educational Communities Using Longitudinal Analysis, Alexa Steidl

Master's Theses

At California State University, Los Angeles and California Polytechnic University, San Luis

Obispo, a longitudinal survey was created in response to the COVID-19 pandemic for students within their respective engineering departments. A combination of nonparametric and longitudinal analysis is performed to evaluate the impacts of the transition to a virtual educational environment and the stressors brought on by the global pandemic. Additional qualitative evaluation is performed to gain insight and make program recommendations to enhance the resilience of individuals in the academic systems. Results demonstrate a large shift in circumstances immediately at the start of the pandemic, with a variety …

Transfer Learning Approach To Powder Bed Fusion Additive Manufacturing Defect Detection, Michael Wu

Master's Theses

Laser powder bed fusion (LPBF) remains a predominately open-loop additive manufacturing process with minimal in-situ quality and process control. Some machines feature optical monitoring systems but lack automated analytical capabilities for real-time defect detection. Recent advances in machine learning (ML) and convolutional neural networks (CNN) present compelling solutions to analyze images in real-time and to develop in-situ monitoring.

Approximately 30,000 selective laser melting (SLM) build images from 31 previous builds are gathered and labeled as either “okay” or “defect”. Then, 14 open-sourced CNN were trained using transfer learning to classify the SLM build images. These models were evaluated by F1 …

A Method For Visualizing The Structural Complexity Of Organizational Architectures, Jacob Michael B. King

Master's Theses

To achieve a high level of performance and efficiency, contemporary aerospace systems must become increasingly complex. While complexity management traditionally focuses on a product’s components and their interconnectedness, organizational representation in complexity analysis is just as essential. This thesis addresses this organizational aspect of complexity through an Organizational Complexity Metric (OCM) to aid complexity management. The OCM augments Sinha’s structural complexity metric for product architectures into a metric that can be applied to organizations. Utilizing nested numerical design structure matrices (DSMs), a compact visual representation of organizational complexity was developed. Within the nested numerical DSM are existing organizational datasets used …

A Simulation Study On Baggage Screening At San Luis Obispo County Regional Airport, Marian Ott

Master's Theses

Efficient passenger flow is a crucial objective at both small and larger airports. One central part of this is the handling of checked luggage which is influenced by necessary security screening. Within this thesis, these processes are studied at San Luis Obispo County Regional Airport. The underlying problem of the airport is its outbound luggage system which was already suffering from delays prior to Covid-19. Delays were never measured and the bottleneck responsible for them was never identified. However, expected growth in passenger and flight volume necessitates to predict when customer dissatisfaction and extensive luggage delays are inevitable, given that …

Comparison Of Classification Algorithms And Undersampling Methods On Employee Churn Prediction: A Case Study Of A Tech Company, Heather Cooper

Master's Theses

Churn prediction is a common data mining problem that many companies face across industries. More commonly, customer churn has been studied extensively within the telecommunications industry where there is low customer retention due to high market competition. Similar to customer churn, employee churn is very costly to a company and by not deploying proper risk mitigation strategies, profits cannot be maximized, and valuable employees may leave the company. The cost to replace an employee is exponentially higher than finding a replacement, so it is in any company’s best interest to prioritize employee retention.

This research combines machine learning techniques with …

Combining Machine Learning And Empirical Engineering Methods Towards Improving Oil Production Forecasting, Andrew J. Allen

Master's Theses

Current methods of production forecasting such as decline curve analysis (DCA) or numerical simulation require years of historical production data, and their accuracy is limited by the choice of model parameters. Unconventional resources have proven challenging to apply traditional methods of production forecasting because they lack long production histories and have extremely variable model parameters. This research proposes a data-driven alternative to reservoir simulation and production forecasting techniques. We create a proxy-well model for predicting cumulative oil production by selecting statistically significant well completion parameters and reservoir information as independent predictor variables in regression-based models. Then, principal component analysis (PCA) …

Design Of A Printed Circuit Board For A Sensorless Three-Phase Brushless Dc Motor Control System, Joshua Castle

Master's Theses

The use of brushless motors has increased in recent years due to superior performance characteristics compared with alternatives. The operation of a brushless motor is dependent upon a separate controller which is often in the form of a printed circuit board. As such, the size and performance capability of the controller can restrict the performance of the overall motor control system so advancements of these controllers further the potential use of BLDC motors. This project outlines the design of a PCB based, sensorless motor controller for operation of a three-phase BLDC motor powered by a 24 V, high current external …

Resource-Constrained Project Scheduling With Autonomous Learning Effects, Jordan M. Ticktin

Master's Theses

It's commonly assumed that experience leads to efficiency, yet this is largely unaccounted for in resource-constrained project scheduling. This thesis considers the idea that learning effects could allow selected activities to be completed within reduced time, if they're scheduled after activities where workers learn relevant skills. This paper computationally explores the effect of this autonomous, intra-project learning on optimal makespan and problem difficulty. A learning extension is proposed to the standard RCPSP scheduling problem. Multiple parameters are considered, including project size, learning frequency, and learning intensity. A test instance generator is developed to adapt the popular PSPLIB library of scheduling …

Characterization Of Resistance Change In Stretchable Silver Ink Screen Printed On Tpu-Laminated Fabrics Under Cyclic Tensile Loading, Corey R. Sutton

Master's Theses

A stretchable silver ink was screen printed to TPU sheets, then tensile coupons of the TPU, both bare and laminated to cotton, Denim and spandex fabric, were subjected to 1000 cycles of 20% uniaxial strain. In-situ resistance measurements of printed traces were processed to generate datasets of maximum and minimum resistance per cycle. A mechanistic fit model was used to predict the resistance behavior of the ink across TPU/fabric levels. The results show that traces strained on TPU laminated to spandex (polyester) fibers had an average rate of increase in resistance significantly lower than that of traces strained on bare …

Application Of Big Data Analytics In Agriculture Supply Chain Management, Sankara Narayanan Mangalam Ananthapadmanabhan

Master's Theses

The increasing trend in frequency of natural disasters in tandem with globalization of business makes the agricultural supply chain significantly vulnerable to disruption. This thesis presents a pragmatic approach for creating a Business Continuity Model that can notify supply chain planners when there is an increase in risk of agriculture supply chain disruption due to natural disasters. The methodology presented in this thesis applied big data analytics and machine learning algorithms along with agriculture product related exponential decay function to create a regionalized composite risk score, that incorporated both direct and indirect risk associated with the Agriculture Fresh Supply Chain. …

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems …

Analysis Of Verification And Validation Techniques For Educational Cubesat Programs, Noah Weitz

Master's Theses

Since their creation, CubeSats have become a valuable educational tool for university science and engineering programs. Unfortunately, while aerospace companies invest resources to develop verification and validation methodologies based on larger-scale aerospace projects, university programs tend to focus resources on spacecraft development. This paper looks at two different types of methodologies in an attempt to improve CubeSat reliability: generating software requirements and utilizing system and software architecture modeling. Both the Consortium Requirements Engineering (CoRE) method for software requirements and the Monterey Phoenix modeling language for architecture modeling were tested for usability in the context of PolySat, Cal Poly's CubeSat research …

An Ergonomics Investigation Of The Application Of Virtual Reality On Training For A Precision Task, Delaney M. Bales

Master's Theses

Virtual reality is rapidly expanding its capabilities and accessibility to consumers. The application of virtual reality in training for precision tasks has been limited to specialized equipment such as a haptic glove or a haptic stylus, but not studied for handheld controllers in consumer-grade systems such as the HTC Vive. A straight-line precision steadiness task was adopted in virtual reality to emulate basic linear movements in industrial operations and disability rehabilitation. This study collected the total time and the error time for the straight-line task in both virtual reality and a physical control experiment for 48 participants. The task was …

Using Computer Vision To Build A Predictive Model Of Fruit Shelf-Life, Nandan G. Thor

Master's Theses

Computer vision is becoming a ubiquitous technology in many industries on account of its speed, accuracy, and long-term cost efficacy. The ability of a computer vision system to quickly and efficiently make quality decisions has made computer vision a popular technology on inspection lines. However, few companies in the agriculture industry use computer vision because of the non-uniformity of sellable produce. The small number of agriculture companies that do utilize computer vision use it to extract features for size sorting or for a binary grading system: if the piece of fruit has a certain color, certain shape, and certain size, …

An Ergonomics Analysis Of Redundancy Effect In Touch Screen Design For The Aged Population, Sarah Riesenberg

Master's Theses

Touch screen technology is rapidly increasing, and at the same time there is a shifting, aging population. As the percentage of the population over the age of 65 increases, adults of the age group are adopting smartphones and tablets more now than ever before. Although older adults are adopting touch screen devices, they face many challenges when interacting with said devices, such as not knowing how to navigate between pages, not knowing where to click for an action to occur, and the touch screen interface is often too sensitive or the buttons are not big enough. Furthermore, the challenges of …

Continuum Modeling Of The Densification Of W-Ni-Fe During Selective Laser Sintering, Connor M. West

Master's Theses

The purpose of this thesis is to effectively model the time history of the temperature distribution during the selective laser sintering process and use this information to investigate the resulting relative density. The temperature is a critical parameter of the process because it directly effects the overall quality of the part. First, an efficient, affordable, and reliable simulation was developed within the finite element software, Abaqus. Next, the results from the simulations were compared to the experimental results performed by Wang et al. (2016). The FEA model consisted of a 3 layer simulation. Multiple simulations at various laser recipes were …

Optimization Of Rfid System Coverage In A Manufacturing Environment, Scott D. Malatesta

Master's Theses

This paper compiles existing ideas, theories, and experiments across multiple disciplines to provide guidance for a company looking to implement an optimal RFID system in their production facility. The desire is to maximize the information received by the system while minimizing the cost. Four potential layouts of RFID antennas, two with overlapping antenna coverage and two with non-overlapping layouts, are first analyzed to understand the special coverage and the number of antennas required. The value of information is then quantified to determine whether higher coverage layouts are worth the additional costs associated with the higher number of antennas required. It …

Multi-Level Analytic Network Process Model To Mitigate Supply Chain Disruptions In Disaster Recovery Planning, Martina Ursula Kroener

Master's Theses

Over the past few decades, environmental changes have led to more frequent occurrences and greater intensities of natural disasters worldwide. In terms of globally connected supply chains, this has resulted in an enormous economical loss for corporations. Therefore, Business Continuity and Disaster Recovery (BC/DR) planning and management has become essential for businesses in order to protect their critical business flow. Yet there is a lack of systematic and transparent methodologies for companies to handle this problem.

Hence, this thesis introduces a novel approach to combine consecutive steps of the Disaster Recovery Planning (DRP) process within one application. The multi-criteria decision-making …

A Simulation Model For Decision Support In Business Continuity Planning, Marissa Anne Mosunich

Master's Theses

Enterprises with a global supply network are at risk of lost revenue as a result of disruptive disasters at supplier locations. Various strategies exist for addressing this risk, and a variety of types of research has been done regarding the identification, assessment and response to the risk of disruption in a supply chain network.

This thesis establishes a decision model to support Business Continuity Planning at the first-tier supplier level. The decision model incorporates discrete-event simulation of supply chain networks (through Simio software), Monte Carlo simulation, and risk index optimization. After modeling disruption vulnerability in a supply chain network, costs …

Cost-Based Decision Making Model For Regional In-House Versus Outsourcing Logistics, Henrik Darren Lee

Master's Theses

This thesis proposes a model for selecting between insourcing logistics for local distribution and outsourcing these functions to a third-party logistics (3PL) company. Supply chain optimization, as well as global supply chain management, are topics that are now well-covered; local distribution, despite its integral function in an organization, is much less researched. Models exist for network design and optimization, but the practical application of these network models may call for decisions and considerations that are not covered in these optimization models.

A breakeven analysis selection model between using in-house logistic system and 3PL is derived, considering various regional parameters. The …

Ergonomics Analysis Of Touchscreen Utilization As A Function Of Preferred Hand And Gender, Jordan E. Odell

Master's Theses

The growth of touchscreen technology has changed the way users interface with a wide range of computing and communication products and systems. Examples range from personal tablets and laptops to industrial applications such as process control, point-of-sales, and ticketing kiosk systems. An important area of application is the automobile industry which is designing cars with touchscreen control panels to replace the previously designed mechanical knobs and buttons. However, interacting with touchscreens does not provide the same tactile feedback as physical mechanisms, therefore they require more precise movement and visual attention, which distracts the user from the primary task.

The purpose …

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …

Multi-Criteria Decision Modeling For Best Value Selections In Target Value Design Integrated Project Delivery, Brent Patrick Griffis

Master's Theses

Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of …

A Set Union Based Formulation For Course Scheduling And Timetabling, Jesse Paul Bukenberger

Master's Theses

The Course Timetabling Problem is a widely studied optimization problem where a number of sections are scheduled in concert with the assignment of students to sections in order to maximize the desirability of the resulting schedule for all stakeholders. This problem is commonly solved as a linear program with variables for each student or group of students with identical schedules. In this paper we explore an alternative formulation that aggregates binary student variables into integer variables denoting the number of students enrolled in a course. Our solution method assumes decomposition of the general schedule into time blocks, and applies a …

Analysis Of Environmentally Friendly Marking Ink For Military Equipment And Electronics, Liang Li

Master's Theses

Recent advancements in corrosion-resistance coating technology has reduce the use of environmentally harmful compounds such as Hexavalent Chromium by replacing Hexavalent Chromium in primers and topcoat. However, marking inks were neglected in the process. Products such as Enthone 50 series are still widely used, which contain compounds such as lead, hexavalent chromium, bisphenol A (BPA), Cadmium Sulfide, and more. Excluding catalyst compositions in Enthone, the chemicals in the ink alone contained three reproductive toxicant and numerous carcinogens. Therefore, it was essential to search and validate the performance of potential marking ink that would meet the standards in military applications.

Eleven …