Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

2016

Computer simulation

Discipline
Institution
Publication
Publication Type

Articles 1 - 17 of 17

Full-Text Articles in Entire DC Network

Radiometrically Accurate Thermal Vehicle Targets For Synthetic Video Development, David B. Rhodes Dec 2016

Radiometrically Accurate Thermal Vehicle Targets For Synthetic Video Development, David B. Rhodes

Theses

Collecting large scientific quality thermal infrared image and video data sets is an expensive time consuming endeavor. Thermal infrared imagers cost much more than comparable visible systems and require skilled experienced operators. Also, time and experienced personnel are required to collect quality ground truth. Often it is advantageous to perform computer simulations as an alternative to collecting image and video data with real camera systems. As long as enough physics is incorporated into the models to give accurately comparable results to real imagery, simulated data can be used interchangeably. Generating synthetic images and video has the added benefit of being …


Design Optimization Of Acoustic Metamaterials And Phononic Crystals With A Time Domain Method, Weiyang Lin Dec 2016

Design Optimization Of Acoustic Metamaterials And Phononic Crystals With A Time Domain Method, Weiyang Lin

Masters Theses and Doctoral Dissertations

A time-dependent adjoint approach for obtaining sensitivity derivatives for shape optimizations of acoustic metamaterials and phononic crystals is presented. The gradient-based design procedure is suitable for large numbers of design variables, and results are shown on achieving effective material properties with a unit cell and the broadband noise reduction with periodic arrays of cylinders. The acoustic wave propagation problem is solved in the time-domain using a Streamline Upwind/Petrov Galerkin formulation. Topology parameterization is accomplished using the homogenization method, and shape optimization is subsequently used afterwards to refine the geometries. Surface parameterization is accomplished using control grids, which are based on …


Evaluation System For Craniosynostosis Surgeries With Computer Simulation And Statistical Modelling, Jing Jin Nov 2016

Evaluation System For Craniosynostosis Surgeries With Computer Simulation And Statistical Modelling, Jing Jin

Electronic Thesis and Dissertation Repository

Craniosynostosis is a pathology in infants when one or more sutures prematurely closed, leading to abnormal skull shape. It has been classified according to the specific suture that has been closed, each of which has a typical skull shape. Surgery is the common treatment to correct the deformed skull shape and to reduce the excessive intracranial pressure. Since every case is unique, the cranial facial teams have difficulties to select an optimum solution for a specific patient from multiple options. In addition, there is not an appropriate quantified measurement existed currently to help cranial facial team to quantitatively evaluate their …


Development And Computer Simulation Of A New Combined Energy-Saving Technological Process Of Production Of High-Quality Wire With Sub-Ultrafine-Grained Structure, Abdrakhman Naizabekov, Sergey Lezhnev, Evgeniy Panin, Igor Mazur Oct 2016

Development And Computer Simulation Of A New Combined Energy-Saving Technological Process Of Production Of High-Quality Wire With Sub-Ultrafine-Grained Structure, Abdrakhman Naizabekov, Sergey Lezhnev, Evgeniy Panin, Igor Mazur

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Research Of The Metal Flow Picture In The Upsetting Based On Computer And Physical Simulation, Konstantin Nikolaevich Solomonov Oct 2016

Research Of The Metal Flow Picture In The Upsetting Based On Computer And Physical Simulation, Konstantin Nikolaevich Solomonov

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Sep 2016

Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

The 2001 European Commission proposal for the Registration, Evaluation and Authorisation of Chemicals (REACH) aims to improve public and environmental health by assessing the toxicity of, and restricting exposure to, potentially toxic chemicals. The greatest benefits are expected to accrue from decreased cancer incidences. Hence the accurate identification of chemical carcinogens must be a top priority for the REACH system. Due to a paucity of human clinical data, the identification of potential human carcinogens has conventionally relied on animal tests. However, our survey of the US Environmental Protection Agency’s (EPA’s) toxic chemicals database revealed that, for a majority of the …


Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Sep 2016

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …


Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Apr 2016

Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, PhD

The 2001 European Commission proposal for the Registration, Evaluation and Authorisation of Chemicals (REACH) aims to improve public and environmental health by assessing the toxicity of, and restricting exposure to, potentially toxic chemicals. The greatest benefits are expected to accrue from decreased cancer incidences. Hence the accurate identification of chemical carcinogens must be a top priority for the REACH system. Due to a paucity of human clinical data, the identification of potential human carcinogens has conventionally relied on animal tests. However, our survey of the US Environmental Protection Agency’s (EPA’s) toxic chemicals database revealed that, for a majority of the …


Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Apr 2016

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, Ph.D.

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …


Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Apr 2016

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jonathan Balcombe, PhD

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …


Creativity In Organizations: Antecedents And Outcomes Of Individual Creativity, Goran Calic Apr 2016

Creativity In Organizations: Antecedents And Outcomes Of Individual Creativity, Goran Calic

Open Access Dissertations

In this dissertation I set out to expand our collective understanding of creativity in organizations. I accomplish this through three related studies, each organized into independent chapters of this dissertation.

The first study explores how demands of organizations, particularly strategic contradictions faced by decision makers, affect creative processes and products. In this chapter I develop the theory of paradoxical creativity, which posits that creative discovery is a function of how strategic contradictions are perceived by decision-makers. The key insight of the theory of paradoxical creativity is that strategic contradictions have independent effects on the two stages of creative discovery (generation …


Framework For Evaluating The Readiness Of Cyber First Responders Responsible For Critical Infrastructure Protection, Jungsang Yoon Mar 2016

Framework For Evaluating The Readiness Of Cyber First Responders Responsible For Critical Infrastructure Protection, Jungsang Yoon

Theses and Dissertations

First responders go through rigorous training and evaluation to ensure they are adequately prepared for an emergency. As an example, firefighters continually evaluate the readiness of their personnel using a defined set of criteria to measure performance for fire suppression and rescue procedures. From a cyber security standpoint, however, this same set of criteria and rigor is severely lacking for the professionals that must detect, respond to and recover from a cyber-based attack against the nation's critical infrastructure. This research provides a framework for evaluating the readiness of cyber first responders responsible for critical infrastructure protection. The framework demonstrates the …


An Openeaagles Framework Extension For Hardware-In-The-Loop Swarm Simulation, Derek B. Worth Mar 2016

An Openeaagles Framework Extension For Hardware-In-The-Loop Swarm Simulation, Derek B. Worth

Theses and Dissertations

Unmanned Aerial Vehicle (UAV) swarm applications, algorithms, and control strategies have experienced steady growth and development over the past 15 years. Yet, to this day, most swarm development efforts have gone untested and thus unimplemented. Cost of aircraft systems, government imposed airspace restrictions, and the lack of adequate modeling and simulation tools are some of the major inhibitors to successful swarm implementation. This thesis examines how the OpenEaagles simulation framework can be extended to bridge this gap. This research aims to utilize Hardware-in-the-Loop (HIL) simulation to provide developers a functional capability to develop and test the behaviors of scalable and …


Sortie Generation Simulation Of A Fighter Squadron, Abdurrahman Sevimli Mar 2016

Sortie Generation Simulation Of A Fighter Squadron, Abdurrahman Sevimli

Theses and Dissertations

The Turkish Air Force utilizes several fighter squadrons to enhance its military capabilities. One of the most critical challenges for these squadrons is generating sorties to meet the currency and demand during both peacetime and wartime. This sortie generation process directly affects the success of both training and operations. In this study, this process is assessed using a discrete event simulation. Air Force decision makers require a simulation tool to conduct “what-if” analysis on how potential changes in the environment affect an F-16 fighter squadron’s sortie generation process. Creating a usable simulation provides decision makers with a flexible tool to …


Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk Jan 2016

Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk

Dartmouth Scholarship

Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …


Integrating A Simple Traffic Incident Model For Rapid Evacuation Analysis, Andrew J. Collins, R. Michael Robinson, Peter Foytik, Craig Jordan, Barry C. Ezell Jan 2016

Integrating A Simple Traffic Incident Model For Rapid Evacuation Analysis, Andrew J. Collins, R. Michael Robinson, Peter Foytik, Craig Jordan, Barry C. Ezell

VMASC Publications

Road transportation networks are a segment of society's critical infrastructure particularly susceptible to service disruptions. Traffic incidents disrupt road networks by producing blockages and increasing travel times, creating significant impacts during emergency events such as evacuations. For this reason, it is extremely important to incorporate traffic incidents in evacuation planning models. Emergency managers and decision makers need tools that enable rapid assessment of multiple, varied scenarios. Many evacuation simulations require high-fidelity data input making them impractical for rapid deployment by practitioners. Since there is such variation in evacuation types and the method of disruption, evacuation models do not require the …


Efficient Modeling And Simulation Of Wavelength Division Multiplexing Dual Polarization Qpsk Optical Fiber Transmission, Siva Kumar Raju Nadimpalli Jan 2016

Efficient Modeling And Simulation Of Wavelength Division Multiplexing Dual Polarization Qpsk Optical Fiber Transmission, Siva Kumar Raju Nadimpalli

All Graduate Theses, Dissertations, and Other Capstone Projects

Due to enormous growth in communications, wavelength division multiplexing (WDM) systems are popular because these systems allow us to expand the capacity of the networks without laying more optical fiber cables. In this thesis, we have systematically derived the coupled nonlinear Schrödinger (CNLS) equations, including a consistent definition of the complex envelope, Fourier transform, the state of polarization, and derivation under the engineering notation. After a discussion of coarse step based second order symmetrized split-step Fourier (SSSF) simulation method, which is applicable to the numerical solution of the CNLS equations, an analytical step-size selection based local error method is applied …