Engineering Commons^™

Heteromorphic To Homeomorphic Shape Match Conversion Toward Fully Automated Mesh Morphing To Match Manufactured Geometry, Robert Ivan Yorgason

Theses and Dissertations

The modern engineering design process includes computer software packages that require approximations to be made when representing geometries. These approximations lead to inherent discrepancies between the design geometry of a part or assembly and the corresponding manufactured geometry. Further approximations are made during the analysis portion of the design process. Manufacturing defects can also occur, which increase the discrepancies between the design and manufactured geometry. These approximations combined with manufacturing defects lead to discrepancies which, for high precision parts, such as jet engine compressor blades, can affect the modal analysis results. In order to account for the manufacturing defects during …

Reservoir Sedimentation: The Economics Of Sustainability, Matthew William George

Theses and Dissertations

Despite mounting demand for a more sustainable worldwide water supply system, available reservoir capacity is relentlessly diminishing due to sedimentation. This fact, coupled with a decrease in the rate of dam construction, indicate an impending water supply dilemma. In the future, dams should be designed following a life cycle management approach rather than the typical short-sighted design life technique.Neither sustainable reservoir lifespans nor intergenerational equity is achieved through conventional cost-benefit analyses (CBA), which render all benefits and costs projected to occur more than several decades into a project as negligible. Consequently, future expenditures, including dam decommissioning or retrofitting with sediment …

Intermediary System Using Image Classification For Online Shopping, Yunan Liu

Theses and Dissertations

Online shopping is becoming a popular option for consumers. Currently, the most common product searching method that online shopping websites provide is keyword search. Most shoppers have to carefully select relevant keywords to search for their favorite products. Finding desired products using a query image for online shopping is currently not available. Image has been used for searching similar images in the database but they are usually not well annotated. Research effort has been devoted to developing reliable image-based retrieval systems for applications such as medical image retrieval and trademark search. None of these developments focuses on improving online shopping …

Calibration Of Rapidscat Over-Land Σ0, Forrest Dayton Minor

Theses and Dissertations

RapidScat is a Ku-band radar that measures the normalized backscatter coefficient σ⁰ of the Earth's surface. Launched in 2015, it currently operates on the International Space Station. Nearly one year into its mission, RapidScat measurements began exhibiting strange behavior that is believed to be caused by a change in receiver gain. Changes in gain are compensated for during post-processing, but the measurements have a lower signal-to-noise ratio (SNR). Calibration and validation of σ⁰ measurements from this low SNR state are performed using extended land targets with various signal strengths. Study areas include the Amazon rainforest, Congo rainforest, Argentina …

An Investigation Of The Impact A Rov Competition Curriculum Has On Student Interest In Stem, Specifically Technology And Engineering, Daniel Gordon Bates

Student Works

This research investigates the impact a Remotely Operated Vehicle (ROV) program has on student interest in, and perception of, technology and engineering (sTEm). ROV programs embed areas of science, technology, engineering and math (STEM) into their curriculum; however, emphasis for this study is placed on interest and perception of the "T" and "E" of STEM. Although there are many articles detailing the benefits of ROV programs, there is little empirical data documenting the impact on student interest and perception of sTEm. This study outlines the background of a few major ROV programs in the U.S.; specifically Utah Underwater Robotics (UUR), …

A General Code To Simulate The Effect Of Indirect Lightning On Overhead Lines Using Emtp-Type Programs, Hasan Jameel Hasan

Masters Theses

In this thesis, a general code is obtained to allow the simulation of the transient response of transmission lines excited by a nearby lightning stroke using EMTP–type programs, namely PSCAD and ATP.

Initially, the frequency domain modeling of single phase and multiconductor transmission lines is described and assessed by means of several application examples. As a second stage, the transmission line model is used to implement an illuminated transmission line model (line excited by an electromagnetic field excitation) using Taylor’s formulation. Then, a general code is developed in MATLAB to obtain the response of a field excited line; this effect …

Comparison Of Safety And Operational Performances For Three Engineering Countermeasures, Ali Hamzah Hussein Alzuhairi

Masters Theses

While there have been many studies on engineering treatments for reducing traffic crashes or for improving intersection efficiency, few studies have been simultaneously taking both impacts into consideration. This thesis analyzed impacts of engineering countermeasures and determines when these countermeasures are cost effective with respect to the amount of traffic and the number of crashes. Both crash reduction and operational costs were compared for analysis. This study specifically investigated three countermeasures: changing from permitted to protected for a left-turn on minor approaches, leading pedestrian interval (LPI), and exclusive pedestrian phase (Barnes Dance). The general Safety Performance Functions (SPFs) from the …

An Exploration Of Cubesat Propulsion, Andrew Davis Hine

Masters Theses

The development of new primary propulsion systems for CubeSats with the capability to complete orbital maneuvers has become a principal focus of many within the CubeSat community. One such propulsion device is the 1 cm Busek RF Ion Thruster (BIT-1). For systems such as the BIT-1 to become mission ready and implementable on spacecraft, preliminary testing must be completed to understand how these propulsion devices will perform when placed onboard. The research and testing performed and presented was used to understand how the BIT-1 propulsion device and others like it will interact with small spacecraft. This was accomplished by means …

Jezik: A Cognitive Translation System Employing A Single, Visible Spectrum Tracking Detector, Davor Bzik

Theses and Dissertations

A link between eye movement mechanics and the mental processing associated with text reading has been established in the past. The pausing of an eye gaze on a specific word within a sentence reflects correctness or fluency of a translated text. A cognitive translation system has been built employing a single, inexpensive web camera without the use of infrared illumination. It was shown that the system translates the text, detects rarely occurring and out-of-context words from eye gaze information, and provides solutions in real time while the user is still reading. The solutions are in form of a translation, definition …

Thermal And Convective Loading Methods For Releasing Hydrophobic Therapeutics From Contact Lenses, Ryan Ruben Horne

Theses and Dissertations

This thesis investigates the feasibility of loading silicone hydrogel (SiHy) contact lenses with two different hydrophobic therapeutics, latanoprost and DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), for treatment of glaucoma and hyperemia respectively. The two methods of loading were 1) thermal loading in an aqueous medium and 2) convective loading in a solution of n-propanol. Dailies Total1® lenses prepared in this manner were tested for their loading and their release into artificial tears. Continuous release over 1-4 days at therapeutic levels is achievable from thermal loading of DMPC, convective loading of DMPC, and convective loading of latanoprost. The DMPC loading processes can be naturally integrated …

A Quantitative Approach To The Identification And Prediction Of Supply Chain Agility, David A. Sheffield

Theses and Dissertations

As the product-release cycle in the tech industry speeds up, there is more pressure on manufacturers to bring new products to market faster than ever. This puts a great deal of pressure on the suppliers of capital equipment used to manufacture these tech products. The supply chain agility of these suppliers is increasingly important. The purpose of this study is three-fold (1) to develop a methodology that can be used by any firm for measuring and ranking the agility of suppliers and finding the root causes of supplier agility, (2) to develop the first-ever fully quantitative measure of supply chain …

Efficiency Of Chlorophyll In Gross Primary Productivity: A Proof Of Concept And Application In Crops, Anatoly A. Gitelson, Yi Peng, Andrés Viña, Timothy J. Arkebauer, James S. Schepers

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they have different photosynthetic pathways (C3 vs. C4), leaf structures (dicot vs. monocot) and canopy architectures (a heliotrophic leaf angle distribution vs. a spherical leaf angle distribution), they cover a large spectrum of biophysical conditions. Our results show that chlorophyll efficiency in primary …

Development Of Strain And Pressure Sensors On Flexible And Stretchable Platforms, Mohammed Mudher Mohammed Ali

Masters Theses

The capability of the human brain to operate in conjunction with human senses and muscles enables us to become powerful autonomous beings. By using these organs, humans can interact with the surrounding environment. Similarly, the combination of sensors with the signal processing of modern electronics enables the interaction with the non-electrical environment.

In this thesis, the work focuses on the design and fabrication of flexible and stretchable sensors which have been receiving an increased interest for applications such as human body movement, tracking in the biomedical industry, object detection, fingerprint sensor as well as for monitoring deformations or structural changes …

A Multi-Carrier Collaborative Solution To Minimize Connectivity-Loss, Michael Wong

Master's Theses

Nearly two-thirds of Americans own a smart phone, and 19% of Americans rely on their smartphone for either accessing valuable information or staying connected with their friends and family across the globe [15]. Staying always-on and always-connected to the Internet is one of the most important and useful features of a smartphone. This connection is used by almost every single application on the device including web browsers, email clients, messaging applications, etc. Unfortunately, the cellular networks on our smartphones are not perfect and do not always have cellular signal. Our devices often lose Internet connection when users are on the …

Analysis Of Electromagnetic Launcher Design And Modeling, Garrett Ross Germany

Master's Theses

This thesis derives working expressions from electromagnetic physical laws to gain a deeper understanding of the nature of railguns. The expressions are refined for ease of use and then compared to electromagnetic simulators that solve complex equations that arise from different rail geometry. Further simplifications lead to an expression for the final velocity of the projectile and showcase the importance of the system resistance to projectile flux gain ratio. A Simulink simulation then incorporates the resulting non-linear differential equations and approximates the projectile velocity over time based on physical dimensions and material properties. Some equations derived can be found in …

A Study Of Constant Voltage Anemometry Frequency Response, Alex D. Powers

Master's Theses

The development of the constant voltage anemometer (CVA) for the boundary layer data system (BLDS) has been motivated by a need for the explicit autonomous measurement of velocity fluctuations in the boundary layer. The frequency response of a sensor operated by CVA has been studied analytically and experimentally. The thermal lag of the sensor is quantified by a time constant, M_CVA. When the time constant is decreased, the half-amplitude cut-off frequency, f_CVA, is increased, thereby decreasing the amount of attenuation during measurements. In this thesis, three main approaches have been outlined in theory and tested experimentally …

Autonomous Formation Flying And Proximity Operations Using Differential Drag On The Mars Atmosphere, Andres Eduardo Villa

Master's Theses

Due to mass and volume constraints on planetary missions, the development of control techniques that do not require fuel are of big interest. For those planets that have a dense enough atmosphere, aerodynamic drag can play an important role. The use of atmospheric differential drag for formation keeping was first proposed by Carolina L. Leonard in 1986, and has been proven to work in Earth atmosphere by many missions. Moreover, atmospheric drag has been used in the Mars atmosphere as aerobraking technique to decelerate landing vehicles, and to circularize the orbit of the spacecraft. Still, no literature was available related …

Design, Manufacture, Dynamic Testing, And Finite Element Analysis Of A Composite 6u Cubesat, Yanina Soledad Hallak

Master's Theses

CubeSats, specially the 6U standard, is nowadays the tendency where many developers point towards. The upscaling size of the standard and payloads entail the increase of the satellite overall mass. Composite materials have demonstrated the ability to fulfill expectations like reducing structural masses, having been applied to different types of spacecraft, including small satellites.

This Thesis is focused on designing, manufacturing, and dynamic testing of a 6U CubeSat made of carbon fiber, fiberglass, and aluminum.

The main objective of this study was obtaining a mass reduction of a 6U CubeSat structure, maintaining the stiffness and strength. Considering the thermal effects …

Empirical Validation Of An In Silico Model Predicting The Fluid Dynamics Of An Iliac Artery Aneurysm, Rachel E. Willis

Master's Theses

Iliac artery aneurysms are considered rare and difficult to detect and treat. Prompt diagnosis and timely intervention are essential, because the incidence of rupture is as high as 50%. The reported mortality rate for patients who undergo surgery for ruptured iliac artery aneurysm ranges from 50% to 70%. This study developed an in-vitro mechanical model of an iliac artery aneurysm to verify the accuracy of computer simulation software. Both the in vitro model and the in silico model can be used for further research to develop better treatment technology. This study also looks at the different types of iliac artery …

Exploring Travel Time Reliability Using Bluetooth Data Collection: A Case Study In San Luis Obispo, California, Krista Purser

Master's Theses

Bluetooth technology applications have improved travel time data collection efforts and allowed for collection of large data sets at a low cost per data unit. Mean travel times between pairs of points are available, but the primary value of this technique is the availability of the entire distribution of travel times throughout multiple days and time periods, allowing for a greater understanding of travel time variations and reliability. The use of these data for transportation planning, engineering and operations continues to expand. Previous applications of similar data sources have included travel demand and simulation model validation, work zone traffic patterns, …

Removing Oil From Fried Foods Via Mechanical Process, Yufay Chow-Yee

Master's Theses

Fried foods are delicious and enjoyed by almost everyone. However, they are not the healthiest foods to eat because of the amount of oil they contain. This thesis, sponsored by Moaero Company founder, Mr. Harrish Bhutani, intends to determine whether a simply designed centrifuge system can remove a reasonable amount of oil from fried foods after it has been deep fried without adversely affecting the texture of the fried food. Due to a large variety in the texture as well as the type of fried foods, and in order to keep the scope of this thesis more focused and feasible, …

Finite Element Modeling Of Delamination Damage In Carbon Fiber Laminates Subject To Low-Velocity Impact And Comparison With Experimental Impact Tests Using Nondestructive Vibrothermography Evaluation, George Rodriguez Iv

Master's Theses

Carbon fiber reinforced composites are utilized in many design applications where high strength, low weight, and/or high stiffness are required. While composite materials can provide high strength and stiffness-to-weight ratios, they are also more complicated to analyze due to their inhomogeneous nature. One important failure mode of composite structures is delamination. This failure mode is common when composite laminates are subject to impact loading.

Various finite element methods for analyzing delamination exist. In this research, a modeling strategy based on contact tiebreak definitions in LS-DYNA^®was used. A finite element model of a low-velocity impact event was created to …

Sysml Based Cubesat Model Design And Integration With The Horizon Simulation Framework, Shaun Luther

Master's Theses

This thesis examines the feasibility of substituting the system input script of Cal Poly’s Horizon Simulation Framework (HSF) with a Model Based Systems Engineering (MBSE) model designed with the Systems Modeling Language (SysML). A concurrent student project, SysML Output Interface Creation for the Horizon Simulation Framework, focused on design of the HSF Translator Plugin which converts SysML models to an HSF specific XML format. A SysML model of the HSF test case, Aeolus, was designed. The original Aeolus HSF input script and the translated SysML input script retained the format and dependency structure required by HSF. Both input scripts …

A Comparison Of Risk Assessment Models For Pipe Replacement And Rehabilitation In A Water Distribution System, Lyle John Nemeth

Master's Theses

A water distribution system is composed of thousands of pipes of varying materials, sizes, and ages. These pipes experience physical, environmental, and operational factors that cause deterioration and ultimately lead to their failure. Pipe deterioration results in increased break rates, decreased hydraulic capacity, and adverse effects on water quality. Pipe failures result in economic losses to the governing municipality due to loss of service, cost of pipe repair/replacement, damage incurred due to flooding, and disruptions to normal business operations. Inspecting the entire water distribution system for deterioration is difficult and economically unfeasible; therefore, it benefits municipalities to utilize a risk …

Exploring Data Driven Models Of Transit Travel Time And Delay, Bobjot Singh Sidhu

Master's Theses

Transit travel time and operating speed influence service attractiveness, operating cost, system efficiency and sustainability. The Tri-County Metropolitan Transportation District of Oregon (TriMet) provides public transportation service in the tri-county Portland metropolitan area. TriMet was one of the first transit agencies to implement a Bus Dispatch System (BDS) as a part of its overall service control and management system. TriMet has had the foresight to fully archive the BDS automatic vehicle location and automatic passenger count data for all bus trips at the stop level since 1997. More recently, the BDS system was upgraded to provide stop-level data plus 5-second …

Feasibility Of Fused Deposition Of Ceramics With Zirconia And Acrylic Binder, Lindsay V. Page

Master's Theses

Processing of ceramics has always been difficult due to how hard and brittle the material is. Fused Deposition of Ceramics (FDC) is a method of additive manufacturing which allows ceramic parts to be built layer by layer, abetting more complex geometries and avoiding the potential to fracture seen with processes such as grinding and milling. In the process of FDC, a polymeric binder system is mixed with ceramic powder for the printing of the part and then burned out to leave a fully ceramic part. This experiment investigates a new combination of materials, zirconia and acrylic binder, optimizing the process …

Polyfs Visualizer, Paul Martin Fallon

Master's Theses

One of the most important operating system topics, file systems, control how we store and access data and form a key point in a computer scientists understanding of the underlying mechanisms of a computer. However, file systems, with their abstract concepts and lack of concrete learning aids, is a confusing subjects for students. Historically at Cal Poly, the CPE 453 Introduction to Operating Systems has been on of the most failed classes in the computing majors, leading to the need for better teaching and learning tools. Tools allowing students to gain concrete examples of abstract concepts could be used to …

An Iteration On The Horizon Simulation Framework To Include .Net And Python Scripting, Morgan Yost

Master's Theses

Modeling and Simulation is a crucial element of the aerospace engineering design pro- cess because it allows designers to thoroughly test their solution before investing in the resources to create it. The Horizon Simulation Framework (HSF) v3.0 is an aerospace modeling and simulation tool that allows the user to verify system level requirements in the early phases of the design process. A low fidelity model of the system that is created by the user is exhaustively tested within the built-in Day-in-the-Life simulator to provide useful information in the form of failed requirements, system bottle necks and leverage points, and potential …

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 …

A Solution To The Circular Restricted N Body Problem In Planetary Systems, Jay R. Iuliano

Master's Theses

This thesis is a brief look at a new solution to a problem that has been approached in many different ways in the past - the N body problem. By focusing on planetary systems, satellite dynamics can be modeled in a fashion similar to the Circular Restricted Three Body Problem (CR3BP) with the Circular Restricted N Body Problem (CRNBP). It was found that this new formulation of the dynamics can then utilize the tools created from all the research into the CR3BP to reassess the possibility of different complex trajectories in systems where there are more than just two large …