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Computational Engineering Commons

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2009

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Articles 1 - 17 of 17

Full-Text Articles in Computational Engineering

Quality-Driven Cross Layer Design For Multimedia Security Over Resource Constrained Wireless Sensor Networks, Wei Wang Dec 2009

Quality-Driven Cross Layer Design For Multimedia Security Over Resource Constrained Wireless Sensor Networks, Wei Wang

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

The strong need for security guarantee, e.g., integrity and authenticity, as well as privacy and confidentiality in wireless multimedia services has driven the development of an emerging research area in low cost Wireless Multimedia Sensor Networks (WMSNs). Unfortunately, those conventional encryption and authentication techniques cannot be applied directly to WMSNs due to inborn challenges such as extremely limited energy, computing and bandwidth resources. This dissertation provides a quality-driven security design and resource allocation framework for WMSNs. The contribution of this dissertation bridges the inter-disciplinary research gap between high layer multimedia signal processing and low layer computer networking. It formulates the …


Sonic Boom Prediction Methods Using Feature-Based Adaptation Of Unstructured Meshes, Jacob Chackasseril Varghese Dec 2009

Sonic Boom Prediction Methods Using Feature-Based Adaptation Of Unstructured Meshes, Jacob Chackasseril Varghese

Masters Theses and Doctoral Dissertations

This study examines the improvement of near-field sonic boom prediction of an inviscid supersonic configuration using two grid generation refinement procedures. The first method uses P_HUGG, a parallel hierarchical Cartesian mesh generation algorithm to generate a volume mesh, with the solution-based mesh adaptation capability of P_HUGG being exploited. The mesh quality was improved using P_OPT, a parallel optimization-based mesh-smoothing program. In the second method, the commercially-available software POINTWISE™ is used for volume mesh generation. Then, P_REFINE, a parallel subdivision refinement code, is used t o adaptively refine the mesh. The effectiveness of capturing far field shocks was examined using TENASI, …


Numerical Simulation Of Mode Transition In A Hydrogen-Fueled Scramjet, Manan Ajay Vyas Nov 2009

Numerical Simulation Of Mode Transition In A Hydrogen-Fueled Scramjet, Manan Ajay Vyas

Master's Theses - Daytona Beach

The Wind-US computational fluid dynamics (CFD) flow solver was used to simulate dual-mode direct-connect ramjet/scramjet engine flowpath tests conducted in the University of Virginia (UVa) Supersonic Combustion Facility (SCF). The objective was to develop a computational capability within Wind-US to aid current hypersonic research and provide insight to flow as well as chemistry details that are not resolved by instruments available. Computational results are compared with experimental data to validate the accuracy of the numerical modeling. These results include two fuel-off non-reacting and eight fuel-on reacting cases with different equivalence ratios, split between one set with a clean (non-vitiated) air …


Parameter Identification Of Hydro Generation System With Fluid Transients Based On Improved Genetic Algorithm, Lin Gao Aug 2009

Parameter Identification Of Hydro Generation System With Fluid Transients Based On Improved Genetic Algorithm, Lin Gao

Lin Gao

More accurate models are adopted for dynamic stability analysis of hydro generation systems but the parameters of these models are often estimated roughly. Inaccurate parameters may decrease the analysis accuracy improved by using an accurate model. An improved genetic algorithm is proposed in this paper to estimate the parameters of a hydro generation system model which contains a series of basic differential equations to represent the flow transients more accurately. The numerical and experimental results show good accordance between the actual systems and the identification results.


Prostate Cancer Biomarker Identification: A Comparative Study, Wenjuan Jiang Jul 2009

Prostate Cancer Biomarker Identification: A Comparative Study, Wenjuan Jiang

Computational Modeling & Simulation Engineering Theses & Dissertations

With the current development of proteomics techniques, the discovery of potential molecular biomarkers for early detection of prostate cancer has been greatly improved. In this thesis, we implemented five classifiers including the support vector machine (SVM), Bayesian Classifier, Decision Tree, Random Forest and the Multilayer perceptron (MLP) to test their effectiveness in prostate cancer biomarker identification using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) tissue imaging data. The classifiers were utilized to discriminate cancer mass spectra from normal ones for the data collected at the Eastern Virginia Medical School (EVMS). There are 94 7 spectra from normal tissues and 27 from …


Comparison Between Direct Quadrature Method Of Moments And The Method Of Classes For Bubbly Flow, Brahim Selma, Rachid Bannari, Pierre Proulx Jun 2009

Comparison Between Direct Quadrature Method Of Moments And The Method Of Classes For Bubbly Flow, Brahim Selma, Rachid Bannari, Pierre Proulx

Rachid BANNARI

No abstract provided.


Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx Jun 2009

Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx

Rachid BANNARI

The design, scale-up and performance evaluation of biological reactors require accurate information about the gas-liquid flow dynamics. In this study, we use CFD techniques to investigate important parameters of the multiphase flow dynamics on an initial airlift bioreactor in order to improve its design. Such parameters are distributions of shear stresses and mass transfer. Our initial proposed design of the airlift bioreactor was used for biomass growing. Specifically to produce cellulase enzyme using the fungus Trichoderma Reesei. However, the morphology of the microorganism obtained in this bioreactor was not appropriated to produce cellulase. Since the microorganism morphology presented a small …


A New Framework For Power System Identification Based On An Improved Genetic Algorithm, Lin Gao May 2009

A New Framework For Power System Identification Based On An Improved Genetic Algorithm, Lin Gao

Lin Gao

Accuracy parameters of power system model are of great importance in stability and security evaluation or simulation. Some of the conventional methods may have inadequate adaptability or effectiveness for identification of different power systems. A general framework for power system identification is proposed based on an improved genetic algorithm with a logarithmic fitness function and an adaptive searching space. It can be used for most power system models (linear or nonlinear) and can readily be performed on different models just by rebuilt corresponding map lists between the parameters and the coefficients of the general model. The numerical experiment and practical …


Proceedings Of The Scientific Conference On Energy And It At Alvsjo Fair, Stockholm March 11-12, 2009 In Connection With The “Energitinget 2009, Dr. Erik Dahlquist, Dr. Jenny Palm May 2009

Proceedings Of The Scientific Conference On Energy And It At Alvsjo Fair, Stockholm March 11-12, 2009 In Connection With The “Energitinget 2009, Dr. Erik Dahlquist, Dr. Jenny Palm

Dr. Erik Dahlquist

This book contains the proceedings from the Energy and IT conference at Alvsjo Energy conference "Energitinget" arranged by Swedish Energy Agency, with approximately 2500 visitors. The papers contain both technical and social science papers, relating to both energy efficiency in buildings and in industry.


State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov Apr 2009

State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Rail pad is one of the main components in ballasted railway track systems. It is inserted between the rail and the sleeper to attenuate dynamic wheel/rail interaction forces, preventing the underlying railway track components from excessive stresses. Generally, the dynamic design of tracks relies on the available data, which are mostly focused on the structural condition at a specific toe load. Recent findings show that track irregularities could significantly amplify the loads on railway tracks. This phenomenon gives rise to a concern that the rail pads may experience higher deterioration rate than anticipated in the past. On this ground, an …


A Coupled Cfd-Kinetic Models For Cellulase Production In Airlift Reactor, Rachid Bannari, Abdelfettah Bannari, Brahim Selma, Pierre Proulx Apr 2009

A Coupled Cfd-Kinetic Models For Cellulase Production In Airlift Reactor, Rachid Bannari, Abdelfettah Bannari, Brahim Selma, Pierre Proulx

Rachid BANNARI

Cellulase production provides a catalyst for cellulose hydrolysis to glucose, to be used for eventual production of ethanol. The transport of reactants may influence the reaction rate remarkably, for the biological reaction, especially the enzymatic reaction, The transport behavior of the components in a biological system should be considered in the model. In this work, we propose a coupled model between hydrodynamics (twoPhaseEuler- Foam) and a kinetic model for batch and fed-batch cellulase enzyme production by T. reesei from cellulose/lactose substrate which is constructed from literature concepts and laboratory data. Good agreement is obtained between the results and experimental data.


Label Oriented Clustering For Social Network Groups, Ahmed El Kholy Feb 2009

Label Oriented Clustering For Social Network Groups, Ahmed El Kholy

Archived Theses and Dissertations

No abstract provided.


Analytical Modeling Of Tree Vibration Generated During Cutting Process, Payman Karvanirabori Jan 2009

Analytical Modeling Of Tree Vibration Generated During Cutting Process, Payman Karvanirabori

Masters Theses 1911 - February 2014

There are several ways to cut down a tree. The piece by piece cutting method is studied in this research. By modeling the cutting process into simple dynamic models and obtaining governing equations of motion of tree and cut piece in each model, the forces during cutting process were calculated. The method was then applied to a set of real data and tree vibrations were compared with field measurements. The study is very rare in the case of the variety of the topics it covers from dynamics and mechanics to finite element modeling of a biological system.


Convergence, Adaptive Refinement, And Scaling In 1d Peridynamics, Florin Bobaru Ph.D., Mijia Yabg Ph.D., Leonardo F. Alves M.S., Stewart A. Silling Ph.D., Ebrahim Askari Ph.D., Jifeng Xu Ph.D. Jan 2009

Convergence, Adaptive Refinement, And Scaling In 1d Peridynamics, Florin Bobaru Ph.D., Mijia Yabg Ph.D., Leonardo F. Alves M.S., Stewart A. Silling Ph.D., Ebrahim Askari Ph.D., Jifeng Xu Ph.D.

Department of Engineering Mechanics: Faculty Publications

We introduce here adaptive refinement algorithms for the non-local method peridynamics, which was proposed (in J. Mech. Phys. Solids 2000; 48:175–209) as a reformulation of classical elasticity for discontinuities and long-range forces. We use scaling of the micromodulus and horizon and discuss the particular features of adaptivity in peridynamics for which multiscale modeling and grid refinement are closely connected. We discuss three types of numerical convergence for peridynamics and obtain uniform convergence to the classical solutions of static and dynamic elasticity problems in 1D in the limit of the horizon going to zero. Continuous micromoduli lead to optimal rates of …


Agent Based Modeling In Computer Graphics And Games, Brian Macnamee Jan 2009

Agent Based Modeling In Computer Graphics And Games, Brian Macnamee

Books/Book Chapters

As graphics technology has improved in recent years, more and more importance has been placed on the behavior of virtual characters in applications set in virtual worlds in areas such as games, movies and simulations. The behavior of virtual characters should be believable in order to create the illusion that these virtual worlds are populated with living characters. This has led to the application of agent-based modeling to the control of these virtual characters. There are a number of advantages of using agent-based modeling techniques which include the fact that they remove the requirement for hand controlling all agents in …


Building Babel: Freeing Multimedia Processing And Delivery From Hard-Coded Formats, Joseph Alfred Thomas-Kerr Jan 2009

Building Babel: Freeing Multimedia Processing And Delivery From Hard-Coded Formats, Joseph Alfred Thomas-Kerr

University of Wollongong Thesis Collection 1954-2016

The amount of multimedia content available via the Internet, and the number of formats in which it is encoded, stored and delivered continues to grow rapidly. So too the number and diversity of the devices and software applications which produce, process and consume such content. This constantly changing landscape presents an increasing challenge to interoperability, since more and more software and hardware must be upgraded as new formats are developed. However, many of the operations performed on multimedia content are similar across coding formats. In recognising this, this thesis proposes several approaches to format-independent media processing, with an emphasis on …


The Development Of Humans – A Study Including Languages, Cultures, Religions And Genetics, Dr. Erik Dahlquist, Dr. Allan Dahlquist Dec 2008

The Development Of Humans – A Study Including Languages, Cultures, Religions And Genetics, Dr. Erik Dahlquist, Dr. Allan Dahlquist

Dr. Erik Dahlquist

The book covers the development of culture, religion, language and genetics of the human population since prehistory. Four main cultures have spread around the globe: 1) Monosyllabic language people with ancestor cult 2) Austroasiatic people with sun worshipping and megalit graves. Counting with 20 as the base 3) Uralic speaking people with kings from the sky, and strong city states. Moon and mother godess. Don´t differentiate between male and female, he and she. 4) Inflectual language speaking people with sky gods and cattles. Indoeuropeans. Often endings differentiating he and she. Shows how original cultures are refelected in todays society.