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Dynamics and Dynamical Systems Commons

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Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, Trenton Bush 2016 University of Massachusetts Amherst

Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, Trenton Bush

Masters Theses

When a solid, ductile particle impacts a substrate at sufficient velocity, the resulting heat, pressure, and plastic deformation can produce bonding at the interface. The use of a supersonic gas flow to accelerate such particles is known as Cold Spray deposition. The Cold Spray process has been commercialized for some metallic materials, but further research is required to unlock the exciting material properties possible with polymeric compounds. In this work, a combined computational and experimental study a) simulated and optimized the nozzle flow conditions necessary to produce bonding in a polyethylene particle, b) developed and fabricated an experimental device, and ...


Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere 2016 Embry-Riddle Aeronautical University

Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere

Publications

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration ...


Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis 2015 University of New Orleans

Electromechanics Of An Ocean Current Turbine, Vasileios Tzelepis

University of New Orleans Theses and Dissertations

The development of a numeric simulation for predicting the performance of an Ocean Current Energy Conversion System is presented in this thesis along with a control system development using a PID controller for the achievement of specified rotational velocity set-points. In the beginning, this numeric model is implemented in MATLAB/Simulink® and it is used to predict the performance of a three phase squirrel single-cage type induction motor/generator in two different cases. The first case is a small 3 meter rotor diameter, 20 kW ocean current turbine with fixed pitch blades, and the second case a 20 meter, 720 ...


An Approach For The Development Of Complex Systems Archetypes, Walter Lee Akers 2015 Old Dominion University

An Approach For The Development Of Complex Systems Archetypes, Walter Lee Akers

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research is to explore the principles and concepts of systems theory in pursuit of a collection of complex systems archetypes that can be used for system exploration and diagnostics. The study begins with an examination of the archetypes and classification systems that already exist in the domain of systems theory. This review includes a critique of their purpose, structure, and general applicability. The research then develops and employs a new approach to grounded theory, using a visual coding model to explore the origins, relationships, and meanings of the principles of systems theory. The goal of the ...


Electromechanical Coupling Behavior Of Dielectric Elastomer Transducers, Jianyou Zhou 2015 The University of Western Ontario

Electromechanical Coupling Behavior Of Dielectric Elastomer Transducers, Jianyou Zhou

Electronic Thesis and Dissertation Repository

Dielectric elastomer transducers with large deformation, high energy output, light weight and low cost have been drawing great interest from both the research and industry communities, and shown potential for versatile applications in biomimetics, dynamics, robotics and energy harvesting. However, in addition to multiple failure modes such as electrical breakdown, electromechanical instability, loss-of-tension and fatigue, the performance of dielectric elastomer transducers are also strongly influenced by the hyperelastic and viscoelastic properties of the material. Also, the interplay among these material properties and the failure modes is rather difficult to predict. Therefore, in order to provide guidelines for the optimal design ...


Analytical And Numerical Analysis Of Low Velocity Impact On Metallic Sandwich Panel With Polyurethane Foam Core, Mohsen Mahdian, Hossein Ebrahimi 2015 University of Guilan

Analytical And Numerical Analysis Of Low Velocity Impact On Metallic Sandwich Panel With Polyurethane Foam Core, Mohsen Mahdian, Hossein Ebrahimi

Hossein Ebrahimi

No abstract provided.


Predictive Modeling Of Oxygen Transmission Through Micro-Perforations For Packaging Applications, Ayman Abdellatief, Bruce A. Welt, Jason Butler, Eric McLamore, Arthur Teixeira, Sanjay Shukla 2015 University of Florida

Predictive Modeling Of Oxygen Transmission Through Micro-Perforations For Packaging Applications, Ayman Abdellatief, Bruce A. Welt, Jason Butler, Eric Mclamore, Arthur Teixeira, Sanjay Shukla

Journal of Applied Packaging Research

Methods for creating precise perforations in respiring produce packaging are being increasingly adopted. Knowledge of oxygen transfer through perforated packaging and oxygen distribution in packages is necessary for successful packaging design of fresh produce. An approach to modeling perforated packaging performance was developed using a cylindrical chamber with precision perforations using Fick’s second law. The model was simulated using two techniques including Finite Element Method (FEM) using commercially available software and Finite Volume Method (FVM) through programming. Perforations were approximated as a source term in the second method. Both simulation techniques showed trends similar to experimental data.


Phase Dynamics Of Locset Control Methodology, Brendan Neschke 2015 University of Tennessee - Knoxville

Phase Dynamics Of Locset Control Methodology, Brendan Neschke

Masters Theses

Single-mode fiber amplifiers produce diffraction-limited beams very efficiently. Maximum beam intensity requires that an array of these amplifiers have their beams coherently combined at the target. Optical path differences and noise adversely affect beam quality. An existing closed loop phase control methodology, called the locking of optical coherence by single-detector electronic-frequency tagging (LOCSET), corrects phase errors in real time by electronically detecting path length differences and sending signals to lithium niobate phase adjusters. Broadening the line-width using “jitter” of the input signal can increase the output power of an individual amplifier by suppressing nonlinearity. The system dynamics of LOCSET are ...


Dynamic Simulation And Neuromuscular Control Of Movement: Applications For Predictive Simulations Of Balance Recovery, Misagh Mansouri Boroujeni 2015 University of Tennessee - Knoxville

Dynamic Simulation And Neuromuscular Control Of Movement: Applications For Predictive Simulations Of Balance Recovery, Misagh Mansouri Boroujeni

Doctoral Dissertations

Balance is among the most challenging tasks for patients with movement disorders. Study and treatment of these disorders could greatly benefit from combined software tools that offer better insights into neuromuscular biomechanics, and predictive capabilities for optimal surgical and rehabilitation treatment planning. A platform was created to combine musculoskeletal modeling, closed-loop forward dynamic simulation, optimization techniques, and neuromuscular control system design. Spinal (stretch-reflex) and supraspinal (operational space task-based) controllers were developed to test simulation-based hypotheses related to balance recovery and movement control. A corrective procedure (rectus femoris transfer surgery) was targeted for children experiencing stiff-knee gait and how this procedure ...


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 2015 University of Dayton

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 ...


A Collocated C0 Finite Element Method: Reduced Quadrature Perspective, Cost Comparison With Standard Finite Elements, And Explicit Structural Dynamics, Dominik Schillinger, John A. Evans, Felix Frischmann, René R. Hiemstra, Ming-Chen Hsu, Thomas J.R. Hughes 2015 University of Minnesota

A Collocated C0 Finite Element Method: Reduced Quadrature Perspective, Cost Comparison With Standard Finite Elements, And Explicit Structural Dynamics, Dominik Schillinger, John A. Evans, Felix Frischmann, René R. Hiemstra, Ming-Chen Hsu, Thomas J.R. Hughes

Mechanical Engineering Publications

We demonstrate the potential of collocation methods for efficient higher-order analysis on standard nodal finite element meshes. We focus on a collocation method that is variationally consistent and geometrically flexible, converges optimally, embraces concepts of reduced quadrature, and leads to symmetric stiffness and diagonal consistent mass matrices. At the same time, it minimizes the evaluation cost per quadrature point, thus reducing formation and assembly effort significantly with respect to standard Galerkin finite element methods. We provide a detailed review of all components of the technology in the context of elastodynamics, that is, weighted residual formulation, nodal basis functions on Gauss ...


Inżynieria Chemiczna Ćw., Wojciech M. Budzianowski 2015 Wroclaw University of Technology

Inżynieria Chemiczna Ćw., Wojciech M. Budzianowski

Wojciech Budzianowski

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Tematyka Prac Doktorskich, Wojciech M. Budzianowski 2015 Wroclaw University of Technology

Tematyka Prac Doktorskich, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Almost Sure Asymptotic Stabilization Of Differential Equations With Time-Varying Delay By Lévy Noise, Dezhi Liu, Weiqun Wang, Jose Luis Menaldi 2015 Nanjing University of Science and Technology

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.


An Agent Based Approach For Simulating Demo Enterprise Models, Mamadou Seck, Joseph Barjis 2015 Old Dominion University

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 ...


Parametric Study Of Self-Centering Concentrically-Braced Frames In Response To Earthquakes, Nicholas F. Roth 2015 The University Of Akron

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 ...


Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme 2015 Iowa State University

Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme

Civil, Construction and Environmental Engineering Publications

The design of closed-loop structural control systems necessitates a certain level of robustness to cope with system uncertainties. Neurocontrollers, a type of adaptive control system, have been proposed to cope with those uncertainties. However, the performance of neural networks can be substantially influenced by the choice of the input space, or the hyperspace in which the representation lies. For instance, input selection may influence computation time, adaptation speed, effects of the curse of dimensionality, understanding of the representation, and model complexity. Input space selection is often overlooked in literature, and inputs are traditionally determined offline for an optimized performance of ...


Blast-Induced Mild Traumatic Brain Injury Through Ear Canal: A Finite Element Study, Praveen Akula, Yi Hua, Linxia Gu 2015 University of Nebraska-Lincoln

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

Mechanical & 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 ...


Authoring Effective Embedded Tutors: An Overview Of The Extensible Problem Specific Tutor (Xpst) System, Stephen B. Gilbert, Stephen B. Blessing, Enruo Guo 2015 Iowa State University

Authoring Effective Embedded Tutors: An Overview Of The Extensible Problem Specific Tutor (Xpst) System, Stephen B. Gilbert, Stephen B. Blessing, Enruo Guo

Industrial and Manufacturing Systems Engineering Publications

The Extensible Problem Specific Tutor (xPST) allows authors who are not cognitive scientists and not programmers to quickly create an intelligent tutoring system that provides instruction akin to a model-tracing tutor. Furthermore, this instruction is overlaid on existing software, so that the learner’s interface does not have to be made from scratch. The xPST architecture allows for extending its capabilities by the addition of plug-ins that communicate with additional third-party software. After reviewing this general architecture, we describe three major implementations that we have created using the xPST system, each using different third-party software as the learner’s interface ...


Using Conceptgrid As An Easy Authoring Technique To Check Natural Language Responses, Stephen B. Blessing, Shrenik Devasani, Stephen B. Gilbert, Jivko Sinapov 2015 University of Tampa

Using Conceptgrid As An Easy Authoring Technique To Check Natural Language Responses, Stephen B. Blessing, Shrenik Devasani, Stephen B. Gilbert, Jivko Sinapov

Industrial and Manufacturing Systems Engineering Publications

ConceptGrid provides a template-style approach to check natural language responses by students using a model-tracing style intelligent tutoring system. The tutor-author creates, using a web-based authoring system, a latticestyle structure that contains the set of required concepts that need to be in a student response. The author can also create just-in-time feedback based on the concepts present or absent in the student's response. ConceptGrid is integrated within the xPST authoring tool and was tested in two experiments, both of which show the efficacy of the technique to check student answers. The first study tested the tutor's effectiveness overall ...


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