Engineering Commons^™

Characterization And Analysis Of Ultrathin Cigs Films And Solar Cells Deposited By 3-Stage Process, Grace Rajan, Krishna Aryal, Shankar Karki, Puruswottam Aryal, Robert W. Collins, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

In view of the large-scale utilization of Cu(In,Ga)Se₂ (CIGS) solar cells for photovoltaic application, it is of interest not only to enhance the conversion efficiency but also to reduce the thickness of the CIGS absorber layer in order to reduce the cost and improve the solar cell manufacturing throughput. In situ and real-time spectroscopic ellipsometry (RTSE) has been used conjointly with ex situ characterizations to understand the properties of ultrathin CIGS films. This enables monitoring the growth process, analyzing the optical properties of the CIGS films during deposition, and extracting composition, film thickness, grain size, and surface roughness which …

Spanish Language Topics Course With An Emphasis On Construction Safety, Austin Changras

Construction Management

The end goal of this research-based project is to evaluate whether a Spanish course with an emphasis on construction site safety would be beneficial to Cal Poly’s Construction Management (CM) program and how it might also benefit the industry. The research orchestrated will be to decipher whether or not there is even a need for this type of class to be included into the curriculum. Along with data research, two separate surveys have been conducted, one administered to the Construction Management student population and the other to industry professionals. Furthermore, George Healy, a fellow CM student, is working on the …

Implementing Bim Management And Process Optimization Tools In Construction Management Curriculum, Jake W. Castillo

Construction Management

As the construction industry rapidly continues to adopt technology and Building Information Modeling practices, we need to ensure that Construction Management curriculum prepares students for what is expected after graduation. Cal Poly’s Construction Management program currently have two Building Information Modeling courses in the curriculum that focus mainly on learning software and while this will be essential for students graduating the Construction Management program, there remains room to improve the courses as the industry adapts. Adding curriculum geared more toward managing the BIM process and learning process optimization skills will not only benefit a higher percentage of students, but will …

Using The Soar Approach To Teach Middle School Students About Math And Science Concepts Found In Engineering, Rachael A. Wagner

Honors Program: Senior Projects (Public)

In order to address the lack of knowledge about the engineering profession in middle-level students, the project described in this Honors Thesis was developed. Through the creation of an afterschool program centered on engineering, students were able to apply the math and science concepts covered to design, build, and test a bridge. One particular lesson from this after-school program was highlighted in this thesis, the lesson covering the Pythagorean Theorem, to demonstrate the use of SOAR methodology in the lesson’s development and later use in the classroom. The effectiveness of the Pythagorean Theorem lesson was evaluated positively based on the …

Road Diet Feasibility Analysis For Nebraska, Brandon L. Purintun

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Many rural towns and cities throughout Nebraska have experienced consistent population decline over the past 50 years, and the highway system once built to accommodate hoped-for growth is not serving the population as well as it could. These towns and cities would benefit from implementing a road diet conversion on their main highways. Within rural communities, road diets are an increasingly popular method of improving safety along major arterials through the reduction of excess capacity in favor of increasing refuge areas for turning vehicles. A typical application might be the restriping of a four-lane undivided highway into a three-lane highway …

Examination Of Steel Pin And Hanger Assembly Performance: Retrofit To Replacement, Chandana Chickamagalur Balakrishna

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A number of steel, multi-beam bridges exist in the United States that contain pin and hanger assemblies. Pin and hanger assemblies are fracture critical members whose failure would result in collapse of the bridge or render it unable to perform its expected functions. As these bridges continue to age, many assemblies have deteriorated to a point where retrofit or replacement has to be considered and performed to maintain intended safety and performance. States have taken various approaches to address the pin and hanger assembly retrofit and replacement options. However, there is no single document that summarizes these approaches.

This research …

Optimized Health Monitoring Plans For A Steel, Double-Track Railway Bridge, Ahmed Rageh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Railway bridges are an essential component of any modern society and play a significant transportation role. During the 19^th and early 20^th centuries steel truss and plate girder bridges were commonly used railway designs, with most of the trusses constructed using pin and eyebar systems and most other load carrying members being riveted, built-up sections.

Many of these bridges are still in use and are subjected to increased railway traffic intensity, loads and speeds. The current practice for evaluating the integrity of bridges in the United States, irrespective of use, is primarily via visual inspection, with those inspections …

Peridynamic Modeling Of Dynamic Fracture In Bio-Inspired Structures For High Velocity Impacts, Sneha Akula

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Bio-inspired damage resistant models have distinct patterns like brick-mortar, Voronoi, helicoidal etc., which show exceptional damage mitigation against high-velocity impacts. These unique patterns increase damage resistance (in some cases up to 3000 times more than the constituent materials) by effectively dispersing the stress waves produced by the impact. Ability to mimic these structures on a larger scale can be ground-breaking and could be used in numerous applications. Advancements in 3D printing have now made possible fabrication of these patterns with ease and at a low cost. Research on dynamic fracture in bio-inspired structures is very limited but it is …

Essays On Applications Of Transportation Network Design And Optimization, Amirali Ghaharikermani

Graduate Theses and Dissertations

In this dissertation, we address different transportation problems. The three main outcomes are: designing a battery swap station network, studying gaps in Empty Container Management literature, designing a model with similar characteristics to the vehicle routing problem as well as implementation scenario for it to be applied for a real-world case.

For the designed battery swap station, a model is developed for customer demand satisfaction that permits construction of different types of BSS in the planning network. Our solution methodology is a Tabu Search algorithm combined with a dynamic programming initialization. Numerous tests showed that the proposed TS approach provides …

Demonstrating Set-Based Design Techniques- A Uav Case Study, Colin Small

Graduate Theses and Dissertations

The Department of Defense (DoD) and Engineered Resilient Systems (ERS) community seek to improve decision making in the Analysis of Alternatives (AoA) process by incorporating resilience and leveraging the capabilities of model-based engineering (MBE) early in the design process. Traditional tradespace exploration utilizing Point-Based Design (PBD) often converges quickly on a solution with subsequent engineering changes to modify the design. However, this process can lead to a suboptimal solution if an incorrect initial solution is chosen. Enabled by MBE, Set-Based Design (SBD) considers sets of all possible solutions and enables down-selecting possibilities to converge on a final solution. Using a …

Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang

Graduate Theses and Dissertations

In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm-700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on …

Low Latency Intrusion Detection In Smart Grids, Israel Zairi Akingeneye

Graduate Theses and Dissertations

The transformation of traditional power grids into smart grids has seen more new technologies such as communication networks and smart meters (sensors) being integrated into the physical infrastructure of the power grids. However, these technologies pose new vulnerabilities to the cybersecurity of power grids as malicious attacks can be launched by adversaries to attack the smart meters and modify the measurement data collected by these meters. If not timely detected and removed, these attacks may lead to inaccurate system state estimation, which is critical to the system operators for control decisions such as economic dispatch and other related functions.

This …

Application Of Modular Multilevel Converters (Mmc) Using Phase-Shifted Pwm And Selective Harmonic Elimination In Distribution Systems, Thouhidul Islam

Graduate Theses and Dissertations

Reducing the size and weight of a power electric system is a prodigious challenge to researchers as the development of the latest technologies emerge in the field of electrical engineering. A similar urge is there to develop a light-weight mobile power substation (MPS) to use in the electric power distribution systems during emergency conditions. This thesis proposes a power electronics based solution using the modular multilevel converter (MMC) topology to design the MPS system. The market-available power semiconductor devices are analyzed and suitable devices are selected to design the system. The phase-shifted pulse width modulation (PS-PWM) and selective harmonic elimination …

Convergent Set-Based Design In Integrated Analysis Of Alternatives: Designing Engineered Resilient Systems, Zephan Wright Wade

Graduate Theses and Dissertations

This thesis presents a comprehensive package for understanding and expanding set-based design quantification through the definition and demonstration of Convergent set-based design (SBD). Convergent SBD is a technique developed for the Engineered Resilient Systems program sponsored by the Department of Defense. Convergent SBD contributes a repeatable methodology with the goal of mathematically eliminating inefficient sets. The study of Convergent SBD led to the development of dominance identification criteria equations using comparison of statistical means. The demonstration of Convergent SBD also illustrates the effect of mission resilience in the tradespace and the impact mission resilience has on preference. Finally, Convergent SBD …

Fabrication And Characterization Of Graphene Based 2d Materials For Supercapacitors, Anishkumar Manoharan

Graduate Theses and Dissertations

Supercapacitors have attracted a lot attention due to their efficient energy storage. In comparison to batteries, supercapacitors have high capacitance, energy, and power densities per unit mass than conventional capacitors. Carbon based materials are most promising in supercapacitor application due to their outstanding physical and electrochemical behavior. In this work, a facile method to synthesize a nanocomposite electrode consisting of annealed carbon from carbon ink and MoS2 was demonstrated. Effects of various aqueous and solid electrolytes were studied. It was found that the nanocomposite electrode with 10% MoS2 and 1M Na2SO4 as the aqueous electrolyte tested using the three electrode …

Gating Methods For High-Voltage Silicon Carbide Power Mosfets, Audrey Dearien

Graduate Theses and Dissertations

The objective of this thesis is to assess the challenges associated with driving Silicon Carbide (SiC) power devices, and to compare the potential gate drive methods for these devices which address those challenges. SiC power devices present many benefits that make them suitable for next generation automotive, power utility grid, and energy management applications. High efficiency, increased power density, and reliability at high-temperatures are some of the main benefits of SiC technology. However, the many challenges associated with these devices have prevented their adoption into industry applications. The argument is made in this thesis that the gate driver is a …

Analyzing Requirements And Traceability Information To Improve Bug Localization, Michael Rath, David Lo, Patrick Mader

Research Collection School Of Computing and Information Systems

Locating bugs in industry-size software systems is time consuming and challenging. An automated approach for assisting the process of tracing from bug descriptions to relevant source code benefits developers. A large body of previous work aims to address this problem and demonstrates considerable achievements. Most existing approaches focus on the key challenge of improving techniques based on textual similarity to identify relevant files. However, there exists a lexical gap between the natural language used to formulate bug reports and the formal source code and its comments. To bridge this gap, state-of-the-art approaches contain a component for analyzing bug history information …

Optimization Of Chemical Kinetic Mechanism For Efficient Computation Of Combustion Process In Advanced Internal Combustion Engine Configurations, Muzammil Arshad

Theses and Dissertations

For the development and optimization of future fuels and automotive engines, computer modeling and simulation has proved itself as an inseparable, efficient and cost effective tool to experimental studies. The traditional reliance of computer models on simplified global reaction steps to simulate the combustion and engine performance parameters, such as in-cylinder pressure, heat release rate and pollutant formation could reduce credibility of the predictions as the global reaction steps depend on arbitrary adjustment of model parameters. This study has incorporated detailed chemistry by augmenting the combustion model of a three dimensional unsteady compressible turbulent Navier-Stokes solver with liquid spray injection …

Mechatronic Carnival, Caroline Kutach, Charlotte Liu, Nic Rodriguez, Laura Wilson

Mechatronics Final Projects

The goal for our design was to create a two-player water gun shooting game. The object of the game is to use a water gun to aim a stream of water at a target and fill up a tank. The player who is able to successfully fill up their tank first is the winner.

The design consists of two water guns that are powered by a pump. They are used to shoot at a target in the backboard of the device. As the tank fills up, LEDs light up to indicate each player’s progress. When a tank is full, all …

Variable Input Pressure Regulator, Sean Farrell, Dupri Grimes, William Mcelvogue, Nathan Richter

Mechatronics Final Projects

The variable input pressure regulation system was designed to carry out a test in accordance with the ASTM E1105 standardized commercial window testing procedure. This testing standard dictates that a negative pressure must be maintained within 2% of a constant value while a curtain wall spray system saturates the window from the outside. The test lasts around 15 - 20 minutes depending on the window type, though it may last longer if the user chooses. Currently, the test is performed by a user regulating differential pressure with a variable pump power dial, a gate valve, and a high precision liquid …

Building A Smart Nation: Singapore’S Digital Journey, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

The journey towards smart city status is a strong global trend as governments around the world strive to harness technology to improve the quality of life for their citizens (United Nations, 2016). The widespread phenomenon of becoming “smart” is a key topic of discussion and research that continues to change as new digital technologies develop (Ishkineeva et al., 2015). The smart cities theme is important because it explores how governments, as providers of public goods, harness digital technologies to improve the lives of citizens around the world in the present and the future.

A Qualitative Research On Marketing And Sales In The Artificial Intelligence Age, Yin Yang, Keng Siau

Research Collection School Of Computing and Information Systems

The age of artificial intelligence is here! Artificial Intelligence, robotics, machine learning, and automation are impacting the field of marketing and sales in an unprecedented way. In this study, the qualitative research methodology will be used to better understand the revolution and evolution of marketing and sales field in the AI age. Multiple case studies will be performed in various marketing and sales units in different organizations. This research is of value to both academics and practitioners as it aims to provide a detailed analysis and documentation of the changes in marketing and sales functionalities and job markets as AI …

Breathing-Based Authentication On Resource-Constrained Iot Devices Using Recurrent Neural Networks, Jagmohan Chauhan, Suranga Seneviratne, Yining Hu, Archan Misra, Aruna Seneviratne, Youngki Lee

Research Collection School Of Computing and Information Systems

Recurrent neural networks (RNNs) have shown promising resultsin audio and speech-processing applications. The increasingpopularity of Internet of Things (IoT) devices makes a strongcase for implementing RNN-based inferences for applicationssuch as acoustics-based authentication and voice commandsfor smart homes. However, the feasibility and performance ofthese inferences on resource-constrained devices remain largelyunexplored. The authors compare traditional machine-learningmodels with deep-learning RNN models for an end-to-endauthentication system based on breathing acoustics.

Real-Time Object Detection And Tracking On Drones, Tu Le

Maseeh Summer Undergraduate Research Experience

Unmanned aerial vehicles, also known as drones, have been more and more widely used in recent decades because of their mobility. They appear in many applications such as farming, search and rescue, entertainment, military, and so on. Such high demands for drones lead to the need of developments in drone technologies. Next generations of commercial and military drones are expected to be aware of surrounding objects while flying autonomously in different terrains and conditions. One of the biggest challenges to drone automation is the ability to detect and track objects of interest in real-time. While there are many robust machine …

K-Means: A Revisit, Wan-Lei Zhao, Cheng-Hao Deng, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Due to its simplicity and versatility, k-means remains popular since it was proposed three decades ago. The performance of k-means has been enhanced from different perspectives over the years. Unfortunately, a good trade-off between quality and efficiency is hardly reached. In this paper, a novel k-means variant is presented. Different from most of k-means variants, the clustering procedure is driven by an explicit objective function, which is feasible for the whole l(2)-space. The classic egg-chicken loop in k-means has been simplified to a pure stochastic optimization procedure. The procedure of k-means becomes simpler and converges to a considerably better local …

Improving Operator Situation Awareness By Phasor Measurement Unit (Pmu) Data Visualization, Esa M. Rantanen, Ernest Fokoue, Jacob Haut, Chandini Ramesh, Kathleen Gegner, Thomas Overbye, Komal Shetye

Articles

The application of phasor measurement unit (PMU) data in the power industry is currently an area of intense interest. The key driver for PMU technology is to use the precise time sources provided by Global Positioning System (GPS) satellites to accurately measure the relative voltage and current phase angles at buses across an interconnect at a very high sampling rate. Presenting PMU data to power system operators in a format that is truly useful for them and that affords improved situation awareness (SA) and fast and accurate decision making is a particular challenge to display design. This report describes development …

Accuracy Of Residential Water Meters In Response To Short, Intermittent Flows, John R. Chadwick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this study, water meter accuracy in response to short, intermittent flows was tested. Burst flows have short durations (a few seconds or less), and occur at a variety of flow rates. For some types of meters, it is difficult to accurately measure short, intermittent flow rates. Depending on the meter type, an intermittent flow can result in either under-registering or over-registering of the actual throughput.

During the testing for this research, water was passed through meters for various time combinations, test setups, and flows. It should be understood that realistically, a household setting will not see burst flows occurring …

Silane Modulation Of Protein Conformation And Self-Assembly, Abul Bashar Mohammad Giasuddin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research focused on development of nanoparticle- based therapeutics against amyloid fibrils. Amyloid fibrils are associated with various diseases such as Parkinson’s, Huntington’s, mad cow disease, Alzheimer’s, and cataracts. Amyloid fibrils develop when proteins change their shape from a native form to a pathogenic “misfolded” form. The misfolded proteins have the ability to recruit more native proteins into the pathogenic forms, which self-assemble into amyloid fibrils that are hallmarks of the various protein-misfolding diseases listed above. Amyloid fibrils are highly resistant to degradation, which may contribute to the symptoms of amyloid diseases. Synthetic drugs, natural compounds, and antibodies are widely …

Radio-Frequency Transmitter Geolocation Using Non-Ideal Received Signal Strength Indicators, Samuel Whiting

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Locating a radio transmitter is important in a number of problems such as finding radio tags, people with radios, and devices that are collecting information in an unauthorized manner. Locating a radio transmitter is inherently difficult because the radio waves of concern are not in the visible spectrum, they reflect and distort easily, and they propagate at the speed of light.

A number of methods for locating transmitters are currently used, the majority of which require expensive hardware and extensive processing. This thesis presents a method of using simpler measurements to produce similar location estimates in order to augment or …

The Effects Of Surge Flows On Residential Water Meters, Ryan P. Weller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

All residential water meters have published flow rates for which they will operate as designed. These specifications include a maximum operating flow rate, which is recommended not to exceed. However, there are situations which may cause a meter to flow above the maximum flow rate. This thesis explores what effect these surge flows have on residential water meters.

Twenty-one 5/8”x3/4” meters were tested in this study: three oscillating pistons, six nutating disks, nine ultrasonic, and three electromagnetic. Testing was done at the Utah Water Research Laboratory using a gravimetric test bench specifically designed for residential water meter testing.

The results …