Engineering Commons^™

Developing Open Source Software Using Version Control Systems: An Introduction To The Git Language For Documenting Your Computational Research, Jared D. Smith, Jonathan D. Herman

All ECSTATIC Materials

Version control systems track the history of code as it is committed (saved) by any number of developers. Have you made a coding error and cannot debug it? Version control systems allow for resetting code back to when it worked, and show what code has changed since previous commits.

The contents of this lecture provide an introduction to the git version control language, GitHub for cloud hosting open source code repositories, and tutorials that demonstrate common and useful git and GitHub practices. This lecture is intended to be coupled with a discussion on creating reproducible computational research.

The zipped folder …

Changes In The Exposure Of California’S Levee-Protected Critical Infrastructure To Flooding Hazard In A Warming Climate, Iman Mallakpour, Mojtaba Sadegh, Amir Aghakouchak

Civil Engineering Faculty Publications and Presentations

Levee systems are an important part of California's water infrastructure, engineered to provide resilience against flooding and reduce flood losses. The growth in California is partly associated with costly infrastructure developments that led to population expansion in the levee protected areas. Therefore, potential changes in the flood hazard could have significant socioeconomic consequences over levee protected areas, especially in the face of a changing climate. In this study, we examine the possible impacts of a warming climate on flood hazard over levee protected land in California. We use gridded maximum daily runoff from global circulation models (GCMs) that represent a …

When Can We Be Sure That Measurement Results Are Consistent: 1-D Interval Case And Beyond, Hani Dbouk, Steffen Schön, Ingo Neumann, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, measurements are characterized by interval uncertainty -- namely, based on each measurement result, the only information that we have about the actual value of the measured quantity is that this value belongs to some interval. If several such intervals -- corresponding to measuring the same quantity -- have an empty intersection, this means that at least one of the corresponding measurement results is an outlier, caused by a malfunction of the measuring instrument. From the purely mathematical viewpoint, if the intersection is non-empty, there is no reason to be suspicious, but from the practical viewpoint, if …

Why Lasso, Ridge Regression, And En: Explanation Based On Soft Computing, Woraphon Yamaka, Hamza Alkhatib, Ingo Neumann, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, observations and measurement results are consistent with many different models -- i.e., the corresponding problem is ill-posed. In such situations, a reasonable idea is to take into account that the values of the corresponding parameters should not be too large; this idea is known as {\it regularization}. Several different regularization techniques have been proposed; empirically the most successful are LASSO method, when we bound the sum of absolute values of the parameters, ridge regression method, when we bound the sum of the squares, and a EN method in which these two approaches are combined. In this …

A Network Graph Technique For The Design Of Electric Aircraft Power Systems, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Today the electrification of flight is more popular than ever, creating a wide array of concept aircraft and associated power system topologies. In order to gain insights into benefits of these varying architectures, this paper introduces the development of a framework for electric aircraft power system (EAPS) optimization. The proposed framework accepts inputs from a designer in the form of component parameters and desired flight mission characteristics. A collective graph representing many architectures is formed, from which, subgraphs or power system topologies meeting the flight requirements are extracted and analyzed. An optimum topology meeting the flight requirements with minimum mass, …

Southern California Regional Transit Training Consortium: Skills Gap & Needs Assessment, Tyler Reeb, Benjamin Olson

Mineta Transportation Institute

The transit sector grows and evolves quickly with the needs of growing, busy cities. With this growth comes a need for more transit workers and more training to ensure workers can best serve their diverse communities. This report contains a transit training needs assessment and gap analysis to identify the most pressing challenges of the evolving transit workforce served by the Southern California Regional Transit Training Consortium (SCRTTC). Most importantly, this report documents and determines SCRTTC priorities to ensure the incumbent and future transit workforce is equipped with the professional and technological skills required to address the transformational trends affecting …

A Multi-Objective Optimization Model To Minimize The Gap In Accessibility To Multi-Use Paths While Maximizing The Economic Efficiency Of Active Transportation Investments For Fresno, California, Chih-Hao Wang

Mineta Transportation Institute

This research examines the accessibility to multi-use paths in a variety of neighborhoods in Fresno, California. This study aims to develop a multi-objective optimization modeling framework to be used by decision makers in transportation and policy to maximize the total accessibility to multi-use paths across the city while minimizing the gap between low- and high- accessibility neighborhoods by an optimal allocation of active transportation. Researchers calculate accessibility to multi-use paths by measuring the total length of multi-use paths (walkway and bikeway) a resident could reach from their own Census block group with a 30-minute cycling ride. The study employs a …

Development Of Reduced Chemical Kinetic Models For The Numerical Simulation Of Combustion And Emissions Behavior Of Representative Conventional And Bio-Derived Fuels, Mazen A. Eldeeb

Mineta Transportation Institute

The study addresses two of the main challenges facing combustion modeling for transportation fuels: simultaneous simulation of non-related combustion problems and reducing the computational cost of the modeling process itself. To address the first challenge, researchers determine a characteristic flame time from thermal diffusivity and laminar burning velocity. Researchers examine parametric dependence of flame time and ignition delay time on pressure, temperature and equivalence ratio for methane, based on validated chemical kinetic mechanisms. The study reveals flame time and ignition delay time show similar temperature dependence, flame time has stronger dependence on equivalence ratio and weaker dependence on pressure than …

Turbulence Investigations In The Core-Flow Of An Internal Combustion Engine, James R. Macdonald

Dissertations

Turbulence significantly impacts the operation of energy conversion devices. In internal combustion (IC) engines, mixing, heat transfer, and combustion are all strongly dependent on the turbulence inside the cylinder. Consequently, knowledge of the state of turbulence is critical for improving our understanding and modeling of engine processes.

Turbulence states may be determined through analysis of the Reynolds stress tensor, which can in turn be experimentally quantified using velocity data. In this research, stereoscopic particle image velocimetry (stereo-PIV) experiments were conducted in a single-cylinder, motored engine with optical access to measure the two-dimensional, three-component (2D-3C) velocity fields throughout the compression stroke. …

Experimental Study Of Collecting Running Water From Moderately Heated Water Vapors Using Turbulence-Induced Particles Collision (Tipc) Device, Hassan Ali Ghazwani

Dissertations

This dissertation describes the development of an alternative technique to collect water vapors or changing any vapor state to liquid state using a device called the turbulence-induced particles collision generator (TIPC). The experiment of collecting water vapors using the TIPC device is conducted at different values of temperature. The spatial patterns of droplets deposited on a wall due to the TIPC are measured at different values of pressure using luminescent oil technique, and the integrated intensity of deposited droplets is calculated. Also, the luminescent oil technique has been used to visualize the deposited particles on a pipe wall. ANSYS FLUENT …

Use Of Dimpling Techniques To Alter The Vibration And Acoustic Characteristics Of Beams And Plates, Mofareh Ghazwani

Dissertations

Structures such as beams and plates can produce potentially high levels of unwanted vibrations and noises in the environment. A method for improving the vibroacoustic characteristics of structures based on creating dimples on its surfaces is presented in this study. The goal of this technique is to keep the mass of the subject structure the same while changing its vibration and sound radiation characteristics. A boundary value model (BVM), derived using Hamilton’s Variational Principle, is used for modeling dimpled beams subjected to various boundary conditions. Using this method, the non-dimensional equations of motion, boundary conditions, and continuity conditions for a …

Experimental And Numerical Investigation Of Free Water Surface Evaporation In Case Of Natural Convection, Hassan Fagehi

Dissertations

Evaporation of water can be considered an essential part of the hydrological cycle. It is important for many technological applications such as industrial cooling towers, air conditioning, solid material drying, distillation, and liquid film cooling. Moreover, the interfacial convection caused by the density gradient belongs to Rayleigh convection, which plays an important role in the evaporation process by means of intensifying heat and mass transfer, as in an isopropanol‒water system. In addition, natural convection, which can be defined as a buoyancy-driven flow, is important in astrophysics, geophysics, and numerous engineering applications such as solar energy systems, cooling of electrical equipment, …

Towards The Design Of A Wideband Reflective Long Period Grating Distributed Sensor, Sohel Rana, Nirmala Kandadai, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, we computationally investigate the effects of metal coating length and coating coverage on the reflected spectrum of a long period grating (LPG) over a broad bandwidth. Simulation results indicate that coating the tail end of the fiber between the LPG and the end facet of the fiber provides a reflected spectrum that mimics the LPG transmission spectrum shape over a 400 nmbandwidth. Based on single LPG simulation results, we present the design of a distributed LPG structure containing a multiple number (n) of LPGs in reflection mode for the first time. Simulation results for n …

Fitness Plug, Evan Lee Ashley

Computer Engineering

My parents only allowed me to play videogames or watch television for a certain number of minutes or hours per day. By limiting screen time, they encouraged me to be active and find other things to do outside of television or videogames. The Fitness Plug aims to do both by converting time exercised to entertainment time; you can only watch television or play videogames for as long as you have exercised.

Pod In Concrete Performance Assessment, A Manoj

Manipal Journal of Science and Technology

The quality of ingredients and their quantity in the concrete mix decide the performance level. As the number of variables on which concrete performance depends increases, it is essential to identify those, to which the performance characteristics are sensitive. Efficacy of Proper Orthogonal Decomposition (POD) in the visualisation of patterns in data, its utility in the identification of crucial variables, prediction of performance levels, and generation of performance indices have been discussed and illustrated.

A Novel Greedy Based Algorithm For Resource Allocation In Cloud Computing Environment, Vijendra Pratap Singh

Manipal Journal of Science and Technology

Resource allocation in a cloud computing environment means a mechanism to allocate different cloudlets to the available cloud resources on the basis of some criteria like cloudlets’ characteristics and/or requirements. It is one of the major challenges for cloud providers. Cloud providers have introduced many models for resource allocation. In this paper, we have proposed a greedy-based resource allocation algorithm. Here, first of all, the given cloudlets are classified into two categories: computational cloudlets and interactive cloudlets on the basis of some parameters. Next according to their category, they are allocated differently. The performance metrics of this newly proposed algorithm …

Prototype System For Implementing The Ultrasonic Guided Wave Method On The Field, Ece Erdogmus, Eric Garcia, Michael Schuller, Ahmad Shoaib Amiri

Nebraska Department of Transportation: Research Reports

This report presents the latest improvements in a recently developed nondestructive testing (NDT) technique for early detection of various flaws such as corrosion, delamination, and concrete cracking in reinforced concrete (RC) bridge decks. The method, named Ultrasonic Guided Wave Leakage (UGWL) method by the developing authors, involves use of internal steel reinforcement (rebar) as a wave guide for transmitting ultrasonic waves through the system and the measurement of leaked energy at the surface of the concrete. This report builds upon the progress made in the previously published phases of the project (M029 and M066), and aims to further explore the …

Fabrication Of Magnetocaloric La(Fe,Si)13 Thick Films, N H. Dung, N B. Doan, P De Rango, L Ranno, Karl G. Sandeman, N M. Dempsey

Publications and Research

La(Fe,Si)₁₃–based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)₁₃, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of …

Study On Secrecy Capacity Of Wireless Sensor Networks Based On Amplify-And-Forward Compressed Sensing Scheme, Jianlan Guo, Yuqiang Chen, Yijun Liu

Journal of System Simulation

Abstract: Due to the limitation of wireless sensor nodes on computation, power energy and storage space, the security issue has become a prevalent concern in the wireless communication. A deep insight on the secrecy capacity of wireless sensor network based on the Amplify-and-Forward (AF) compressed sensing scheme was offered providing a corresponding calculable capacity threshold. Moreover, a feasible algorithm based on augmented Lagrange method for the reconstruction of communication signals was proposed. Furthermore, the impact of the secrecy capacity was discussed to various numbers of active sensor nodes, relay nodes and eavesdropper nodes. Simulation results demonstrate the validity of the …

Economic Comparisons Of Variable Rate Irrigation And Fertigation With Fixed (Uniform) Rate Irrigation And Fertigation And Pre-Plant Fertilizer Management For Maize In Three Soils, Vasudha Sharma, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Extensive field research for data collection to conduct economic comparisons of variable rate irrigation (VRI) with fixed (uniform) rate irrigation (FRI) and no irrigation (NI) in combination with three nitrogen application strategies of fixed (uniform) rate fertigation (FRF), variable rate fertigation (VRF) and pre-plant nitrogen (PP) management for maize (Zea mays L.) were conducted. Research was conducted in three soil types [(i) Crete silt loam (S1); (ii) Hastings silty clay loam (S2); and (iii) Hastings silt loam (S3)] for three growing seasons (2015, 2016 and 2017) in Nebraska, USA. For the economic analyses, the average initial investment of the …

Cascaded Voltage Clamping And Ldo Offline Power Supply, Elizabeth Davis, Timothy Jeong

Electrical Engineering

Offline power supplies are necessary for any sort of electronic device that utilizes wall power. For offline power supplies, it is a common practice to use the switching mode method where the high voltage AC input is first rectified and then switched at high frequency to a much lower voltage. This method has been known to be very efficient. Also, it’s more efficient than a linear supply method where the AC input is stepped down and then linearly regulated down to a low voltage. Despite the efficiency benefit, the switching method employs a high frequency transformer and inductor. This will …

Bi-Directional Dc-Dc Converter, John W. Hamlin, Oscar Ambriz, Luis Onofre

Electrical Engineering

This project was developed with the purpose of creating an efficient energy management system for the DC House project, with a centralized 12V battery system fed by a 48V Multiple Input Single Output Source (MISO). The energy management system will consist of a bidirectional DC-DC converter. During the day when the renewable sources produce enough energy to fulfill the load’s energy demand, the converter will make use of the excess energy by taking a 48V DC input and stepping it down to a 12V DC output in order to charge a 12V 100 Ah battery. When renewable sources can no …

Miso Dc-Dc Farmbot, Quyen Thi Nguyen, Brian Armijo, Astha Adhikari

Electrical Engineering

Making use of renewable energy directly from the location of production requires converting source power into usable power. The specific scope of this project focuses on the DC to DC conversion within a user friendly universal farmbot system. Since renewable sources vary widely in voltage and current, a wide input-range DC to DC converter is desired. Physical isolation, long lifespan, and adverse weather requires safe and reliable final product specifications. The goal of a very wide customer base drives the need for a product that does not require tinkering to get working, but to be usable out of the box …

Lawn Buddy, Jayson Johnston, Andrew Brown, Jacob Maljian

Electrical Engineering

Grass lawns are a common hallmark of the American home. In 2019, a survey from the National Association of Landscape Professionals found that 81% of all Americans owned a lawn [1]. Mowing is a time consuming and costly chore that is part of maintaining a grass lawn. The manual labor in mowing a lawn can exceed 40 hours per year [2]. People commonly incur weekly costs on mowing services to save time. Traditional gas powered mowers are physically demanding and use engines that need routine maintenance. They operate loudly enough that users should be wearing hearing protection and the noise …

Electricity Price Prediction With Computational Intelligence, Toan Hoang

Electrical Engineering

Electricity price depends on numerous factors including the weather, location, time of year/month/day (summer, holidays, day/night, etc.), consumption, and market changes or disruptions. The power loss in the transmission lines and the use of electricity also affect the load's price. Forecasting about the electricity price provides future trends and patterns consumption of the users. Forecasting electricity price is crucially important for producers and consumers in the energy trading markets. It is a complicated task because of the uncertainty behaviors and demand fluctuation. The maximization of profit for participants is highly associated with the bidding strategies. Multiple forecasting electricity price tools …

Plant Growing Control With Modicon M580, Brittany M.Y. Won, Eileen T. Tran

Electrical Engineering

Currently, the Industrial Power and Controls lab is being developed by the Cal Poly Electrical Engineering department. The lab is equipped with recently donated Modicon M580 Programmable Logic Controllers (PLCs) from Schneider Electric. In addition to PLCs, Schneider Electric also donated Human Machine Interfaces (HMI) and input/output modules. This project focuses on the creation of a lab experiment that will give future Cal Poly electrical engineering students hands-on experience with this equipment. To show students the broad range of PLCs and the role that electrical engineering plays in various industries, this experiment focuses on the agriculture industry, but more specifically, …

Energy And Economic Losses Due To Soiling On Utility Scale Pv Systems To Guide Timing Of Cost Effective Cleaning, Jackson P. Puckett, Maximilian M. Sosa, Brandon F. Grossman

Electrical Engineering

The energy and associated economic losses due to soiling on both residential and utility scale PV (photovoltaic) systems can be both significant and avoidable. Losses from 1.2% up to 6% have been reported, which is of interest to system operators [1]. Modules may be cleaned to reduce losses, but this comes with an offsetting economic cost. A quantification of energy losses, and the corresponding economic loss, will allow a determination of a closer to optimal cleaning schedule depending on the level of soiling and corresponding energy loss. Two methods are proposed and compared. Method 1 uses an ARES Soiling Measurement …

Photovoltaic Emulator Labview Based Modeling And Simulation, Jeffrey So, Eric Jau Tse

Electrical Engineering

The design goal for this project is to create a system capable of creating a consistent testing environment for photovoltaic inverters and charge controllers. The solution is to create a photovoltaic emulator which is a DC power supply that would have the same electrical output characteristics to a photovoltaic panel. In current systems, consistency problems arise when depending on nature to conduct tests on PV modules because it is impossible to properly replicate scenarios while testing specific conditions. This project will provide the user the ability to test their PV modules under various parameters which replicate real-world scenarios such as …

Sweep-N-Go 3.0, Maria Cortelyou Pieroni

Electrical Engineering

This project improves the current performance of the Sweep-N-Go LabVIEW program used in Cal Poly electrical engineering laboratories. Sweep-N-Go expedites the laboratory data collection process through automated testing. The new version of the program (Sweep-N-Go Version 3.0) reduces user debugging time, improves sustainability, increases efficiency, and considers all new lab bench equipment. Sweep-N-Go Version 3.0 includes an enhanced Graphical User Interface (GUI) to optimize user-efficiency and user-friendliness according to student survey feedback. To further achieve usability, this program has been well documented online, outlining LabVIEW functions, such as how to open the program in LabVIEW, how to run an executable …

Dual Axis Solar Panel Tracker, Xavier Joseph Lugue, Javier Harrison, Nicholas Ryan Wolfe

Electrical Engineering

Photovoltaic systems generate more energy when orthogonally facing the sun where solar cells absorb the most light. By creating an effective, autonomous solar tracking system, the developed solar panels consistently generate maximum energy while using less power. Dual axis solar trackers surpass single axis trackers in energy generation, however, their cost and reliability provide a significant drawback. This project develops different algorithmic implementations designed to provide optimal and efficient behavior for photovoltaic systems. These algorithms adjust the solar panel’s position appropriately with the sun’s location, weather conditions, and selected operating modes. The solar tracking system’s operations include latitudinal axis capability …