Engineering Commons^™

Novel Multi-User Chirp Signaling Schemes For Future Aviation Communication Applications, Nozhan Hosseini

Theses and Dissertations

Many wireless communication systems will need to accommodate a larger number of users in the future. One application in particular in which this is critical is low data rate, long range communication links with very large numbers of nodes, such as the internet of things (IoT), possibly the internet of flying things (IoFT), etc. These systems demand advanced multi-access techniques with minimal multiple access interference (MAI). They should also be robust to multiple impairments, including multipath channel distortions, Doppler spreading, and interference. Chirp waveforms are one type of waveform set that can satisfy future system demands in the presence of …

Guided-Wave Shm And Nde Of Composite Structures: Modeling And Experiments, Hanfei Mei

Theses and Dissertations

The extensive use of composites in aerospace structures has posed new challenges for implementing effective structural health monitoring (SHM) and nondestructive evaluation (NDE) techniques due to the general anisotropic behavior and complex damage scenarios in composites. This dissertation addresses the SHM and NDE of composites using ultrasonic guided waves, with an emphasis on theoretical modeling and experimental validation of guided-wave propagation and interaction with damage in composites. A semi-analytical finite element (SAFE) approach is presented to calculate guided-wave dispersion curves in composites. The theoretical framework is formulated using the finite element method (FEM) to describe the material variation along the …

Theoretical Investigation Of The Biomass Conversion On Transition Metal Surfaces Based On Density Functional Theory Calculations And Machine Learning, Wenqiang Yang

Theses and Dissertations

During the past decades, heterogenous catalyzed conversion of biomass to hydrocarbons with similar or identical properties to conventional fossil fuels has gained significantly academic and industrial interest. However, the conventional heterogeneous catalysts such as sulfided NiMo/Al₂O₃ and CoMo/Al₂O₃ used have various drawbacks, such as short catalyst lifetime and high sulfur content of product. To overcome the limitations of the conventional sulfided catalysts, new catalysts must be developed, which requires a better understanding of the reaction mechanism of the biomass conversion. Based on density functional theory, in this thesis, we reported a computational calculation study …

Fundamental Understanding Of Plasma Discharge Formation In Liquid And Multiphase Configurations Through Multiphysics Modeling, Ali Charchi Aghdam

Theses and Dissertations

During the last two decades, non-thermal plasma discharges in and in contact with liquids have received significant attention due to their wide range of applications including chemical analysis, medical, water treatment, fuel processing, etc. Despite the tremendous interest and advances attained in the experimental studies, modeling efforts providing a comprehensive understanding of the underlying physicochemical processes are limited. There is still no unified theory on plasma formation in dense medium and various theories have been proposed such as the presence of bubbles and tunneling which are topics of debate. In the first part of this study, a mathematical model is …

Congestion-Clearing Payments To Passengers, Paul Minett, John S. Niles, Richard W. Lee, Brittany Bogue

Mineta Transportation Institute

Peak period motor vehicle traffic volume congests roads all over the world. This project hypothesizes implementing congestion- clearing payments to passengers as a permanent congestion-management solution. Ongoing congestion-free travel would be achieved by removing existing congestion, and absorbing (re)generated demand, at costs that would be expected to increase as the total number of travelers increases over time. The project develops a comprehensive, step-by-step methodology to calculate the benefits and costs of paying for drivers to become passengers at a congestion-clearing level and to maintain this level over time. The method is derived from the literature, analysis by the project team, …

Stability Of Fiber-Reinforced Bridge Bearings Under Compression And Shear Loads, Andrea Calabrese, Simone Galano, Tran Nghiem

Mineta Transportation Institute

Fiber-Reinforced Bearings (FRBs) have proven to be a valuable rubber-based base isolation technology in which flexible fiber reinforcements are used to replace the steel layers commonly adopted for the manufacturing of Laminated Rubber Bearings (LRBs). Thanks to the low weight and cost of FRBs, these devices could prove to be instrumental for the promotion of base isolation applications to houses and residential buildings of developing countries in seismic regions. This report presents the results of a large set of Finite Element Analyses (FEAs) aimed at assessing the performance of FRBs under combined axial and shear loads. The effects of different …

A Multimodal Approach For Monitoring Driving Behavior And Emotions, Arash Tavakoli, Vahid Balali, Arsalan Heydarian

Mineta Transportation Institute

Studies have indicated that emotions can significantly be influenced by environmental factors; these factors can also significantly influence drivers’ emotional state and, accordingly, their driving behavior. Furthermore, as the demand for autonomous vehicles is expected to significantly increase within the next decade, a proper understanding of drivers’/passengers’ emotions, behavior, and preferences will be needed in order to create an acceptable level of trust with humans. This paper proposes a novel semi-automated approach for understanding the effect of environmental factors on drivers’ emotions and behavioral changes through a naturalistic driving study. This setup includes a frontal road and facial camera, a …

Freeways And Farms: Veggielution & Taylor Street Urban Farms Study, Joshua Baur, Ashley Estrada

Mineta Transportation Institute

This report presents the results of a project conducted by researchers at San Jose State University in partnership with Veggielution and Taylor Street Farm staff, funded by the Mineta Transportation Institute in San Jose, CA. The research team interviewed staff and volunteer farm workers to explore how nearby roadways impact experiences at farm sites. Research on outdoor nature-based recreation consistently identifies peaceful, natural site characteristics as important to a positive outdoor experience. This project sought to identify whether farm user attitudes and experiences would be consistent with these research findings resulting in farm users reporting that nearby roadways negatively impacted …

Case Study: Diesel-Powered Loaders Compared To Hybrid Loaders In Heavy Civil Construction, Jesus O. Pena

Construction Management

With the construction industry constantly changing, the environmental impacts of greenhouses gases have become a huge concern. Many contractors are adapting and switching over to hybrid powered systems to allow for more energy saving methods for heavy equipment, an increase in productivity, and efficient construction equipment that comply with emission regulations. The goal for this paper is to analyze the feasibility of heavy civil construction companies switching over from conventional diesel-powered wheel loaders to hybrid wheel loaders. Due to the competitive and saturated market in roadwork construction, many contractors have already begun to invest into hybrid systems. This provides cost …

Magnetically Induced Carrier Distribution In A Composite Rod Of Piezoelectric Semiconductors And Piezomagnetics, Guolin Wang, Jinxi Liu, Wenjie Feng, Jiashi Yang

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, we study the behavior of a composite rod consisting of a piezoelectric semiconductor layer and two piezomagnetic layers under an applied axial magnetic field. Based on the phenomenological theories of piezoelectric semiconductors and piezomagnetics, a one-dimensional model is developed from which an analytical solution is obtained. The explicit expressions of the coupled fields and the numerical results show that an axially applied magnetic field produces extensional deformation through piezomagnetic coupling, the extension then produces polarization through piezoelectric coupling, and the polarization then causes the redistribution of mobile charges. Thus, the composite rod exhibits a coupling between the …

Development Of A Mash Test Level 4 Open Concrete Bridge Rail, Jacob Delone

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

An open concrete bridge rail was designed and developed according to safety performance guidelines in the American Association of State Highway Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH) for Test Level 4 (TL-4). Systems designed and developed under previous guidance were studied, and their geometric information and full-scale crash testing performance was studied to establish the geometry of the new bridge rail. Yield-Line Theory and the AASHTO Post and Beam design methods were studied, and a modified version of the AASHTO Post and Beam method was utilized to determine the capacity of the new open concrete bridge rail. …

Development Of An Improved Arterial Roadway Performance Reliability Methodology, Ernest Tufuor

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

The need for reliable performance measures of urban arterial roadways is increasing because of the rise in traffic congestion and the high value of travel time. Consequently, travel time reliability (TTR), which combines components of measures of central tendency and measures of dispersion of travel times, has recently received considerable research interest.

The basis of all TTR metrics is the travel time distribution (TTD). Estimating and forecasting arterial TTDs for TTR analysis is the focus of this dissertation. This dissertation proposes a new TTR methodology that is a marked improvement on recent TTR estimation and forecasting methodologies including the current …

A Novel Wideband Decoupling Network For Two Antennas Based On The Wilkinson Power Divider, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, a wideband decoupling network (DN) is presented based on the Wilkinson power divider (WPD). The DN is composed of 2 two-way unequal WPDs, three transmission lines (TLs), and two reactive components. Two techniques are introduced for the wideband performance: 1) by using the WPD with high output isolation, the antenna matching becomes independent of antenna decoupling. So, the decoupled antennas with the proposed DN could perform broad impedance bandwidths without using matching networks and 2) the DN is designed to minimize antennas' coupling coefficients at two frequencies, which collectively contribute to a broader decoupling bandwidth. In addition, …

The Ethical Challenges Of Antimicrobial Resistance For Nurse Practitioners, Sarah Oerther, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Antimicrobial resistance (AMR) is one of the most challenging worldwide health threats facing modern medicine (Centers for Disease Control, 2018; Logan & Bonomo, 2016; World Health Organization, 2018; Zerr et al., 2014). According to the World Health Organization (2018), when antimicrobial drugs are no longer effective at killing infections caused by bacteria, fungi, parasites and viruses, this is called AMR. AMR leads to drug-resistant infections (World Health Organization, 2018). Nurse practitioners need to be leaders in mitigating risks associated with antimicrobial use, including ethical dilemmas surrounding AMR (Centers for Disease Control, 2018; Logan & Bonomo, 2016; World Health Organization, 2018; …

Monocular Visual Inertial Odometry Using Learning-Based Methods, Yuan Tian

Doctoral Dissertations and Master's Theses

Precise pose information is a fundamental prerequisite for numerous applications in robotics, Artificial Intelligent and mobile computing. Many well-developed algorithms have been established using a single sensor or multiple sensors. Visual Inertial Odometry (VIO) uses images and inertial measurements to estimate the motion and is considered a key technology for GPS-denied localization in the real world and also virtual reality and augmented reality.

This study develops three novel learning-based approaches to Odometry estimation using a monocular camera and inertial measurement unit. The networks are well-trained on standard datasets, KITTI and EuROC, and a custom dataset using supervised, unsupervised and semi-supervised …

Piezoresistive Hybrid Nanocomposites For Strain And Damage Sensing: Experimental And Numerical Analysis, Audrey Jean-Miche Gbaguidi

Doctoral Dissertations and Master's Theses

Carbon nanomaterials such as carbon nanotubes (CNTs) and graphite nanoplatelets (GNPs) demonstrate remarkable electrical and mechanical properties, which suggest promising structural and functional applications as fillers for polymer nanocomposites.

The piezoresistive behavior of these nanocomposites makes them ideal for sensing applications. Besides, hybrid nanocomposites with multiple fillers like carbon nanotubes (CNTs) and graphite nanoplatelets (GNPs) are known to exhibit improved electrical and mechanical performance when compared to mono-filler composites.

To comprehensively understand the mechanisms of electrical percolation, conductivity, and piezoresistivity in hybrid nanocomposites, the author develops a two-dimensional (2D) and a three-dimensional (3D) computational Monte Carlo percolation network models for …

Topology Optimization And Analysis Of Thermal And Mechanical Metamaterials, Lee Alacoque

Doctoral Dissertations and Master's Theses

To take advantage of multi-material additive manufacturing technology using mixtures of metal alloys, a topology optimization framework is developed to synthesize high-strength spatially periodic metamaterials possessing unique thermoelastic properties. A thermal and mechanical stress analysis formulation based on homogenization theory is developed and is used in a regional scaled aggregation stress constraint method, and a method of worst-case stress minimization is also included to efficiently address load uncertainty. It is shown that the two stress-based techniques lead to thermal expansion properties that are highly sensitive to small changes in material distribution and composition. To resolve this issue, a uniform manufacturing …

Three-Dimensional, Vision-Based Proportional Navigation For Uav Collision Avoidance, Guanhong Gao

Doctoral Dissertations and Master's Theses

As the number of potential applications for Unmanned Aerial Vehicles (UAVs) keeps rising steadily, the chances that these devices will operate in close proximity to static or dynamic obstacles also increases. Therefore, collision avoidance is an important challenge to overcome for Unmanned Aerial Vehicle operations. Electro-optical devices have several advantages such as light weight, low cost, low algorithm requirements with respect to computational power and possibly night vision capabilities. Therefore, vision-based Unmanned Aerial Vehicle collision avoidance has received considerable attention. Although much progress has been made in collision avoidance systems (CAS), most approaches are focused on two-dimensional environments. In order …

An Open Source, Autonomous, Vision-Based Algorithm For Hazard Detection And Avoidance For Celestial Body Landing, Daniel Posada

Doctoral Dissertations and Master's Theses

Planetary exploration is one of the main goals that humankind has established as a must for space exploration in order to be prepared for colonizing new places and provide scientific data for a better understanding of the formation of our solar system. In order to provide a safe approach, several safety measures must be undertaken to guarantee not only the success of the mission but also the safety of the crew. One of these safety measures is the Autonomous Hazard, Detection, and Avoidance (HDA) sub-system for celestial body landers that will enable different spacecraft to complete solar system exploration. The …

Contributions To The Understanding Of Ship Airwakes Using Advanced Flow Diagnostic Techniques, Dhuree Seth

Doctoral Dissertations and Master's Theses

The objective of this research was to better characterize the complex, three dimensional, unsteady aerodynamic flows produced by the superstructure of a ship, which is referred to as an airwake. This problem is relevant and important because the turbulent airwake significantly and adversely affects the ability for rotorcraft to operate safely from the decks of Navy ships. To this end, a series of wind tunnel measurements were performed on the SFS2 simplified frigate shape, which has a flight deck at its stern. The measurements were performed with and without a simulated atmospheric boundary layer (ABL), which included the aerodynamic scaling …

Python Implementation Of Batch Least-Squares Filter For Satellite Orbit Determination, Austin Ogle

Doctoral Dissertations and Master's Theses

Accurate orbit determination techniques are fundamental to the maintenance and execution of any ongoing space-based mission. This project serves as a guide and demonstration of a batch sequential least-squares filter for Earth-orbiting satellites using exclusively open-source technologies. The target audience for this project was an academic institution aiming to keep track of an irregularly documented satellite. The observation function mimics a telescope, accepting right ascension and declination as measured values.

State propagation was handled using the Poliastro library. This package boasts FORTRANlevel speed by utilizing the DOPRI8 integrator, explicitly calling FORTRAN code. Matrix inversion was solved using the SciPy banded …

Availability-Resilient Control Of Uncertain Linear Stochastic Networked Control Systems, Chandreyee Bhowmick, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

The resilient output feedback control of linear networked control (NCS) system with uncertain dynamics in the presence of Gaussian noise is presented under the denial of service (DoS) attacks on communication networks. The DoS attacks on the sensor-to-controller (S-C) and controller-to-actuator (C-A) networks induce random packet losses. The NCS is viewed as a jump linear system, where the linear NCS matrices are a function of induced losses that are considered unknown. A set of novel correlation detectors is introduced to detect packet drops in the network channels using the property of Gaussian noise. By using an augmented system representation, the …

Dipole Source Reconstruction By Convolutional Neural Networks, Jiayi He, Qiaolei Huang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Equivalent dipole moments are widely used for noise source reconstruction in radio frequency interference (RFI) study. The equivalent dipole sources are usually extracted from measured near-field pattern. This paper introduces a machine learning based method to extract the dipole moments. A convolutional neural network is trained to perform a multi-label classification to determine the type of dipole moments. The locations of the dipole moments are obtained from the global averaging pooling layer. Then the magnitude and phase of the dipoles can be calculated from least square (LSQ) optimization. The proposed method is tested on simulated near-field patterns. The comparison between …

Decoupling Capacitor Placement Optimization With Lagrange Multiplier Method, Zhifei Xu, Jun Wang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a decoupling capacitor placement optimization method based on the cavity model and Lagrange multiplier. The variable conditions associating with coordinates (x,y) of input impedance expression based on the cavity model are combined with the Lagrange multiplier method. The decoupling capacitor optimum placement within a defined area of the board can be found through the proposed analytical method. The example of finding an optimum location of the decoupling capacitor within a defined area of the power delivery network is exposed, the results are compared to the brute-force method to prove the effectiveness of the proposed method.

Online Optimal Adaptive Control Of A Class Of Uncertain Nonlinear Discrete-Time Systems, Rohollah Moghadam, Pappa Natarajan, Krishnan Raghavan, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multi-layer neural network (MNN) based online optimal adaptive regulation of a class of nonlinear discrete-time systems in affine form with uncertain internal dynamics is introduced. The multi-layer neural networks (MNN)-based actor-critic framework is utilized to estimate the optimal control input and cost function. The temporal difference (TD) error is derived from the difference between actual and estimated cost function. The MNN weights of both critic and actor are tuned at every sampling instant as a function of the instantaneous temporal difference and control policy errors. The proposed approach does not require the selection of any basis …

Dynamic Trajectory Generation And A Robust Controller To Intercept A Moving Ball In A Game Setting, Ravi Prakash, Laxmidhar Behera, Santhakumar Mohan, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Complex and interactive robot manipulation skills, such as playing a game of table tennis against a human opponent, are a novel problem with multifaceted challenges. Accurate dynamic trajectory generation in order to respond to the tennis ball from the opponent and a novel control scheme for robust and high-performance tracking of the ball in such dynamic situations is a prerequisite to winning the game. In this paper, the dynamic movement primitives (DMPs) are employed for the stable generation of dynamic trajectories in the presence of environmental uncertainties such as ball position and velocity, opponent position and velocity and so on. …

Empirical Modeling Of Contact Intermodulation Effect On Coaxial Connectors, Xiong Chen, Yongning He, Ming Yu, David J. Pommerenke, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

An empirical modeling of contact nonlinearity-induced intermodulation (IM) effect on the coaxial connector is presented in this article. The IM weights on inner and outer conductors are clarified using the measurement method. The contact degeneration-induced IM evolution is quantized by considering the contact coupling effect between the inner and outer conductors. This article demonstrated a set of test methods to quantify the oxide-induced nonlinearity with contact degeneration effects, and these methods can evaluate the contact IM products and further predict the low IM lifetime of passive devices.

Decoupling Capacitor Power Ground Via Layout Analysis For Multi-Layered Pcb Pdns, Biyao Zhao, Shuang Liang, Samuel Connor, Matteo Cocchini, Brice Achkir, Albert E. Ruehli, Bruce Archambeault, Jun Fan, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A modeling methodology to calculate the decoupling capacitor interconnect inductance in a multi-layer PCB is proposed herein. The methodology is based on the resonant cavity model of parallel planes. The self-inductance and mutual inductance are extracted to understand the via configuration influence on the effectiveness of decoupling capacitors. A special layout of decoupling capacitor is proposed to increase the effectiveness of the decoupling capacitors by taking maximum advantage of the mutual inductance between interconnect vias with two decoupling capacitors placed in a pair, and two pairs of power and ground vias placed in alternating directions as close as possible. The …

Bs News July/August

Building Services Engineering

No abstract provided.

Random Packing Material In Disinfection Contactors: Effects On Final Drinking Water Quality, Jessica L. Baker, Susan K. De Long, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the concern about biofilm growth on random packing material (RPM) used to enhance the hydraulic disinfection efficiency of a chlorine contactor. The inflow, outflow, and RPM were monitored for heterotrophic bacteria (via heterotrophic plate counts) and Pseudomonas aeruginosa as indicators of bacteriological water quality and the presence of biofilm. The results of this study show that there was no substantial biofilm growth in a lab-scale chlorine contactor and no substantial increase in bacterial counts for the bulk outflow over a 10-week period. Thus, the potential for excessive biofilm growth should not be considered a barrier concerning the …