Dynamics and Dynamical Systems Commons^™

Intensity And Resolution Enhancement Of Local Regions For Object Detection And Tracking In Wide Area Surveillance, Evan Krieger, Vijayan K. Asari, Saibabu Arigela, Theus H. Aspiras

Electrical and Computer Engineering Faculty Publications

Object tracking in wide area motion imagery is a complex problem that consists of object detection and target tracking over time. This challenge can be solved by human analysts who naturally have the ability to keep track of an object in a scene. A computer vision solution for object tracking has the potential to be a much faster and efficient solution. However, a computer vision solution faces certain challenges that do not affect a human analyst. To overcome these challenges, a tracking process is proposed that is inspired by the known advantages of a human analyst.

First, the focus of …

Almost Sure Asymptotic Stabilization Of Differential Equations With Time-Varying Delay By Lévy Noise, Dezhi Liu, Weiqun Wang, Jose Luis Menaldi

Mathematics Faculty Research Publications

This paper aims to determine that the Lévy noise can stabilize the given differential equations with time-varying delay, which has generalized the Brownian motion case. An analysis is developed and sufficient conditions on the stabilization for stochastic differential equations with time-varying delay are presented. Our stabilization criteria is in terms of linear matrix inequalities (LMIs), whence the feedback controls can be designed more easily in practice.

Blast-Induced Mild Traumatic Brain Injury Through Ear Canal: A Finite Element Study, Praveen Akula, Yi Hua, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Purpose The role of ear canal in transmitting blast waves to the brain is not clear. The goal of this work is to characterize the influence of ear canal on blast-induced mild traumatic brain injury through a computational approach.

Methods A three-dimensional human head model with single-side ear canal details was reconstructed from computed tomography images. The ear canal was positioned either facing the incident blast wave or facing away from the blast wave.

Results The blast wave-head interaction has demonstrated that the overpressure within the ear canal was substantially amplified when the ear directly faced the blast wave. When …

Parametric Study Of Self-Centering Concentrically-Braced Frames In Response To Earthquakes, Nicholas F. Roth

Williams Honors College, Honors Research Projects

This research project consisted of the use of computer aided numerical software to test the response of an earthquake resistance system within various buildings when exposed to various design-level earthquakes. This research project is an extension of an existing NSF research project. The relevant questions and investigations of this and the greater project surround the performance of an earthquake resistance system with the intentions of better understanding its abilities and limitations. This project has been aided by Dr. David Roke, the faculty sponsor, in order to perform the research and collect, organize, and analyze the data. This research was performed …

An Agent Based Approach For Simulating Demo Enterprise Models, Mamadou Seck, Joseph Barjis

Engineering Management & Systems Engineering Faculty Publications

DEMO (design and engineering methodology for organization) is a theoretically grounded methodology for rigorous enterprise modeling. It provides relevant concepts from a construction perspective. As the methodology gains a wider audience, there is a growing interest in simulating DEMO models. Most attempts to develop a simulation approach for enterprise models in general, and the DEMO methodology in particular, are based on process oriented conceptualizations that are typically implementation in a discrete event paradigm. In this paper, we propose a conceptual framework for the translation of DEMO models into an agent based simulation. We will describe the DEMO methodology in some …

Viscosity Dependence Of Faraday Wave Formation Thresholds, Lisa M. Slaughter

Symposium

This experiment uses an electromagnetic shaker to produce standing wave patterns on the surface of a vertically oscillating sample of silicon liquid. These surface waves, known as Faraday waves, form shapes such as squares, lines, and hexagons. They are known to be dependent upon the frequency and amplitude of the forcing as well as on the viscosity and depth of the liquid in the dish. At a depth of 4mm and for various silicon liquids having kinematic viscosities of 10, 20, and 38 cSt, we determined the acceleration at which patterns form for frequencies between 10 and 60 Hz. For …

Liquid Slosh Analysis Using Smoothed Particle Hydrodynamics, Kristopher S. Field

Doctoral Dissertations and Master's Theses

The purpose of the research described here is to study the implementation of Smoothed Particle Hydrodynamics (SPH) algorithms as an adequate means for propellant slosh simulations in 1g and 0g environments. The dualSPHysics solver has been adapted for propellant slosh simulations. Simulated sloshing liquid frequency and damping ratio data for 1g cases has been compared to existing experiments for both spherical and prismatic container geometries. The 0g case has been studied to determine what further modifications would be required to obtain realistic simulations results. The findings in this research will be used to create a sloshing simulation to determine torques …

Applying Spiking Neural Network Simulation To Neuromodulatory Autonomous Robot Control, Cameron Muhammad

Phi Kappa Phi Research Symposium (Archived)

In this paper, simulation of the brain based on an artificial spiking neuron model is used to create a self-learning algorithm. The spiking neuron simulation is used to demonstrate a neuromodulation program in which the reward seeking properties of dopamine, the risk-adverse effects of serotonin, and the attention-focusing effects of the cholinergic and noradrenergic systems are applied to a mobile robotic platform as it moves autonomously throughout an environment. External stimuli is recorded by the program as spiking “events” that result in corresponding amounts of dopamine and serotonin influenced spiking patterns. These spiking patterns affect how the robot adapts to …

Designing Meaningful Molecular Dynamics (Md) Simulations: The Lithiation Of Silicon, María Camila Rincon, Alejandro Strachan, Hojin Kim, David Guzman, Mathew Cherukara

The Summer Undergraduate Research Fellowship (SURF) Symposium

Molecular dynamics (MD) is used to understand the properties of materials by following the time evolution of the system and exploring the interactions between its constituent atoms. MD simulation allows making reliable predictions of various properties of materials; however, designing useful computer experiments is a complex task that requires the appropriate selection of interatomic interactions (force fields) and other conditions. In this work we discuss some aspects of molecular dynamics that would help the inexperienced users design reliable simulations. The simulation of the lithiation process of silicon is taken as an example for better understanding.

Modeling The Impact Of Simulated Educational Interventions On The Use And Abuse Of Pharmaceutical Opioids In The United States: A Report On Initial Efforts, Wayne Wakeland, Alexandra E. Nielsen, Teresa D. Schmidt, Dennis Mccarty, Lynn Webster, John Fitzgerald, J. David Haddox

Complex Systems Faculty Publications and Presentations

Three educational interventions were simulated in a system dynamics model of the medical use, trafficking, and nonmedical use of pharmaceutical opioids. The study relied on secondary data obtained in the literature for the period of 1995 to 2008 as well as expert panel recommendations regarding model parameters and structure. The behavior of the resulting systems-level model was tested for fit against reference behavior data. After the base model was tested, logic to represent three educational interventions was added and the impact of each intervention on simulated overdose deaths was evaluated over a 7-year evaluation period, 2008 to 2015. Principal findings …

Reward-Driven Training Of Random Boolean Network Reservoirs For Model-Free Environments, Padmashri Gargesa

Dissertations and Theses

Reservoir Computing (RC) is an emerging machine learning paradigm where a fixed kernel, built from a randomly connected "reservoir" with sufficiently rich dynamics, is capable of expanding the problem space in a non-linear fashion to a higher dimensional feature space. These features can then be interpreted by a linear readout layer that is trained by a gradient descent method. In comparison to traditional neural networks, only the output layer needs to be trained, which leads to a significant computational advantage. In addition, the short term memory of the reservoir dynamics has the ability to transform a complex temporal input state …

Use Of Comsol Simulation For Undergraduate Fluid Dynamics Course, Hyun J. Kwon

Faculty Publications

The COMSOL software was used to introduce CFD and teach fluid dynamics more effectively. Introduction of CFD has become an important part of fluid dynamics in recent years; however, undergraduate students have less access to practical exposure to it, unless they take additional elective courses which are seldom offered in undergrad predominant institutes. Simulation has become an essential step in designing and optimizing process in many engineering problems. Therefore, the COMSOL simulation project was assigned to undergraduate CFD as a part of their term project to enhance their exposure to simulation software and help understanding the use of simulation on …

Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba

Theses and Dissertations--Electrical and Computer Engineering

Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …

Dynamical Properties Of Ferroelectric Perovskites (Ba,Sr)Tio3 And Pb(Zr,Ti)O3 Systems From First Principles, Jeevaka Weerasinghe

Graduate Theses and Dissertations

A first-principles-based effective Hamiltonian scheme which incorporates coupling between ferroelectric (FE) and antiferrodistortive (AFD) motions is applied to Pb(Zr,Ti)O₃ alloys. It validates the existence of two modes of E symmetry (rather than the single E(1TO) soft mode) in the 50-75 cm^-1 range for temperatures smaller than 200 K and for compositions falling within the Rhombohedral R3c phase. Coupling between long-range-ordered FE and AFD motions is shown to be the cause of the additional mode and more insight into its nature is provided. This scheme is further used to reveal a field-induced anticrossing involving FE and AFD degrees of …

Molecular Dynamics Study Of Diffusion Of O2 Penetrates In Uncrosslinked Polydimethysiloxane (Pdms), Crosslinked Pdms, And Pdms-Based Nanocomposites, Varun Ullal

Graduate Theses and Dissertations

Molecular dynamics simulations are used to study diffusion of O₂ molecules in pure polydimethysiloxane (PDMS), crosslinked PDMS, and PDMS-based nanocomposites. The PDMS chains and penetrates are modeled using a hybrid interatomic potential which treats the Si-O atoms along the chain backbone explicitly while coarse-graining the methyl side groups and penetrates. By tracking the diffusion of penetrates in the system and subsequently computing their mean-squared displacement, diffusion coefficients are obtained. In pure PDMS models of varying molecular weight, diffusivity of the O₂2 penetrates is found to have an inverse relationship with chain length. Simulation models with longer chains …

Vibration-Based Health Monitoring Of Multiple-Stage Gear Train And Differential Planetary Transmission Involving Teeth Damage And Backlash Nonlinearity, Andrew Patrick Sommer

Master's Theses

The objective of this thesis is to develop vibration-based fault detection strategies for on-line condition monitoring of gear transmission systems. The study divides the thesis into three sections. First of all, the local stresses created by a root fatigue crack on a pinion spur gear are analyzed using a quasi-static finite element model and non-linear contact mechanics simulation. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. The second section is dedicated to fixed axis power trains. Torsional vibration …

Simulation Of Temperature Distributions In Tissue Upon Laser Pulse Irradiation Including Water Mass Transfer, Deepthi Nagulapally

Electrical & Computer Engineering Theses & Dissertations

Lasers, due to their unique characteristics, have tremendous applications in the medical field. Generally all laser applications in hie-medicine involve the propagation of laser energy through tissue. Energy is deposited giving rise to many physical, hie-chemical, and mechanical effects. Among these are dynamical changes in the local temperature distributions within the tissue. Analysis of the temperature changes requires the creation of an appropriate optical transmission and heat flow model that incorporates user specified laser parameters. Here, a numerical simulation model was developed to study both steady state and time dependent temperature distributions due to pulsed laser radiation within user specified …