Computational Engineering Commons^™

Dnad, A Simple Tool For Automatic Differentiation Of Fortran Codes Using Dual Numbers, Wenbin Yu, Maxwell Blair

Mechanical and Aerospace Engineering Faculty Publications

DNAD (dual number automatic differentiation) is a simple, general-purpose tool to automatically differentiate Fortran codes written in modern Fortran (F90/95/2003) or legacy codes written in previous version of the Fortran language. It implements the forward mode of automatic differentiation using the arithmetic of dual numbers and the operator overloading feature of F90/95/2003. Very minimum changes of the source codes are needed to compute the first derivatives of Fortran programs. The advantages of DNAD in comparison to other existing similar computer codes are its programming simplicity, extensibility, and computational efficiency. Specifically, DNAD is more accurate and efficient than the popular complex-step …

The Unstructured Grid Incompressible Navier-Stokes Algorithm For Convective Heat Transfer Based On Artificial Compressibility, Jessica Elaine Kress

Masters Theses and Doctoral Dissertations

The development of an explicit unstructured grid finite-volume scheme for solving the full incompressible Navier-Stokes equations along with the energy equation in a strongly coupled manner is presented. The Boussinesq approximation is utilized to account for thermal buoyancy. The method of artificial compressibilty is used to solve the resulting equations in a time marching fashion. Roe's approximate Riemann solver is used for the construction of the numerical flux. An eigensystem is derived for the flux Jacobian matrix, which is used in the evaluation of the numerical flux and the characteristic variable boundary conditions. The resulting algorithm is validated by simulating …

Tone-2 Tones Discrimination Task Comparing Audio And Haptics, Lorenzo Picinali, Christopher Feakes, Davide Andrea Mauro, Brian F. G. Katz

Computer Sciences and Electrical Engineering Faculty Research

To investigating the capabilities of human beings to differentiate between tactile-vibratory stimuli with the same fundamental frequency but with different spectral content, this study concerns discrimination tasks comparing audio and haptic performances. Using an up-down 1 dB step adaptive procedure, the experimental protocol consists of measuring the discrimination threshold between a pure tone signal and a stimulus composed of two concurrent pure tones, changing the amplitude and frequency of the second tone. The task is performed employing exactly the same experimental apparatus (computer, AD-DA converters, amplifiers and drivers) for both audio and tactile modalities. The results show that it is …

Semi-Automatic Simulation Initialization By Mining Structured And Unstructured Data Formats From Local And Web Data Sources, Olcay Sahin

Computational Modeling & Simulation Engineering Theses & Dissertations

Initialization is one of the most important processes for obtaining successful results from a simulation. However, initialization is a challenge when 1) a simulation requires hundreds or even thousands of input parameters or 2) re-initializing the simulation due to different initial conditions or runtime errors. These challenges lead to the modeler spending more time initializing a simulation and may lead to errors due to poor input data.

This thesis proposes two semi-automatic simulation initialization approaches that provide initialization using data mining from structured and unstructured data formats from local and web data sources. First, the System Initialization with Retrieval (SIR) …

Design And Comparison Of Immersive Interactive Learning And Instructional Techniques For 3d Virtual Laboratories, Shuo Ren

Computational Modeling & Simulation Engineering Theses & Dissertations

Virtual reality (VR) as a learning environment plays an important role m engineering education. Utilizing the VR learning environment as a supplement to engineering-based laboratories is especially beneficial for students to prepare for the physical experiment and to grasp the experiment objectives and procedures. Such a methodology can also play a significant role in distance education.

This work presents the methodology design for the physical-to-virtual transformation of two undergraduate mechanical engineering laboratory experiments, namely the "Jet Impact Force on Vanes (Jet Force Lab)" and the "Elastic Test of a Beam in Pure Bending (Beam Bending Lab)" at Old Dominion University. …

Orientation-Invariant Ecg-Based Virtual Pathology Stethoscope Tracking For Standardized Patient Heart Auscultation, Nahom B. Kidane

Computational Modeling & Simulation Engineering Theses & Dissertations

Cardiac auscultation (CA), the act of listening to the heart sounds, is a critical physician's skill that provides substantial information for diagnosing many cardiovascular disorders; therefore, competent training can be a key for accurate and reliable diagnosis. The teaching of CA has been an area of recognized importance since the inception of the stethoscope. However, recent changes in health-care, such as limited student access to patients and higher reliance on competing technologies have made it challenging to teach bedside CA techniques.

Over the past few decades, standardized patients (SPs), individuals trained to portray real patients, have been widely used for …

Primitivec-Adl: Primitive Component Architecture Description Language, Basel Magableh

Articles

In this paper, we introduce an architecture descrip- tion language (ADL) for PCOMs (a context oriented component model). The language is described at three levels: (1) Building blocks (PCOMs context oriented components types) (2) Connec- tors, which connect components externally and internally, and (3) Architectural Configuration, which includes a full description of composition and decomposition mechanisms.

The contribution is designing ADL. That supports context- orinted component by providing new architecture elements, which fulfil the requirements of designing context oriented component based applications. Context oriented component is a behavioural unit composed of static parts and dynamic parts. A PCOMs component model …

Tweeting For Learning: A Critical Analysis Of Research On Microblogging In Education Published In 2008-2011, Fei Gao, Tian Luo, Ke Zhang

Visual Communications and Technology Education Faculty Publications

This study critically analyzed the current body of published research on microblogging in education (MIE) to build a deep and comprehensive understanding of this increasingly popular phenomenon. Twenty-one studies on MIE in 2008-2011 were selected based on the selection criteria and analyzed to answer the following questions: (a) What types of research have been published on MIE? (b) How was microblogging used for teaching and learning in these studies? (c) What educational benefits did microblogging have on teaching and learning? and (d) What suggestions and implications did the current research have for future MIE research and practices? The analysis suggested …

Analysis And Implementation Of A High-Order Reconstruction Algorithm For An Unstructured Finite Volume Flow Solver, Shane Edmond Sawyer

Masters Theses and Doctoral Dissertations

A high-order scheme is examined an implemented in an unstructured solver. The motivation for this researcher is driven by research goals to simulate field equations, particularly those of fluid dynamics, with high fidelity. High-order schemes overcome computational limitations by computing comparable solutions on grids that are coarser than grids required by a second-order flow solver. The scheme was chosen based on two criteria. The first being that it is well documented in the literature for two-dimensional flow solvers. The second is that the scheme is extendable to the framework used in the Tenasi flow solver developed at the University of …

Mesh Generation Using A Correspondence Distance Field, Nicholas Szapiro

Masters Theses and Doctoral Dissertations

The central tool of this work is a correspondence distance field to discrete surface points embedded within a quadtree data structure. The theory, development, and implementation of the distance field tool are described, and two main applications to two-dimensional mesh generation are presented with extension to three-dimensional capabilities in mind. First is a method for surface-oriented mesh generation from a sufficiently dense set of discrete surface points without connectivity information. Contour levels of distance from the body are specified and correspondences oriented normally to the contours are created. Regions of merging fronts inside and between objects are detected in the …

Extended Pcr Rules For Dynamic Frames, Florentin Smarandache, Jean Dezert

Branch Mathematics and Statistics Faculty and Staff Publications

In most of classical fusion problems modeled from belief functions, the frame of discernment is considered as static. This means that the set of elements in the frame and the underlying integrity constraints of the frame are fixed forever and they do not change with time. In some applications, like in target tracking for example, the use of such invariant frame is not very appropriate because it can truly change with time. So it is necessary to adapt the Proportional Conflict Redistribution fusion rules (PCR5 and PCR6) for working with dynamical frames. In this paper, we propose an extension of …

Clearing Paths For Emergency Vehicles Using Shock Wave Theory And Vehicle-To-Vehicle Communication, Craig Austin Jordan

Computational Modeling & Simulation Engineering Theses & Dissertations

A new strategy to enable an EV to navigate through congestion at signalized intersections more efficiently has been developed and is presented in this thesis. The proposed strategy involves communicating control messages to vehicles to change their driving behavior and to traffic signals to change their timing plans so that EV s can proceed through congested intersections as quickly as possible. To achieve this, specific vehicles are instructed to hold their positions to create a split in the vehicle queue at a critical location in one lane. The split allows the EV to change lanes and proceed unimpeded at its …

A Multi-Paradigm Modeling Framework For Modeling And Simulating Problem Situations, Christopher James Lynch

Computational Modeling & Simulation Engineering Theses & Dissertations

Problem situations are problems whose specifications are not universally agreed upon making them a challenge to be modeled and simulated. Models of problem situations depart from the premise of well-defined problems, problems where stakeholders disagree, but also modelers' interpretations play a role in their design and computer implementation.

This thesis proposes a multi-paradigm modeling framework for modeling and simulating problem situations in order to explore the problem space of the problem situations and answer specific modeling questions.

The proposed framework implements the Modeling and Simulation (M&S) System Development Framework (MS-SDF), which is a methodology for modeling a problem situation while …

Efficient Algorithms For Fast Integration On Large Data Sets From Multiple Sources, Tian Mi, Sanguthevar Rajasekaran, Robert H. Aseltine

Open Access Author Fund Awardees' Articles

Background

Recent large scale deployments of health information technology have created opportunities for the integration of patient medical records with disparate public health, human service, and educational databases to provide comprehensive information related to health and development. Data integration techniques, which identify records belonging to the same individual that reside in multiple data sets, are essential to these efforts. Several algorithms have been proposed in the literatures that are adept in integrating records from two different datasets. Our algorithms are aimed at integrating multiple (in particular more than two) datasets efficiently.

Methods

Hierarchical clustering based solutions are used to integrate …

Real-Time Musical Analysis Of Polyphonic Guitar Audio, John E. Hartquist

Master's Theses

In this thesis, we analyze the audio signal of a guitar to extract musical data in real-time. Specifically, the pitch and octave of notes and chords are displayed over time. Previous work has shown that non-negative matrix factorization is an effective method for classifying the pitches of simultaneous notes. We explore the effect of window size, hop length, and other parameters to maximize the resolution and accuracy of the output.

Other groups have required prerecorded note samples to build a library of note templates to search for. We automate this step and compute the library at run-time, tuning it specifically …

High Fidelity Thermocline Tracking Algorithm Using Weighted Essentially Non-Oscillatory Schemes, Claudia L. Guevara^, Kiran Kumar, Vinod Kumar*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Smart Home Prototype, Logistics & Planning, David G. Guzman^, Virgilio Gonzalez*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

The Implementation Of A Visco-Hyperelastic Numerical Material Model For Simulating The Behaviour Of Polymer Foam Materials, Conor Briody, Barry Duignan, Stephen Jerrams, John Tiernan

Articles

Polyurethane foam has been in use for some time in wheelchair seating systems as it offers good pressure relieving capabilities in most cases. However, little characterisation work has gone into seating foam materials by comparison with conventional elastomeric materials. Accurate material models could allow better prediction of foam in-service behaviour, which could potentially improve seating design practises. The objective of this work was to develop an approach for the validation of hyperelastic and viscoelastic material model parameters used to simulate polyurethane foam behaviour. Material parameters were identified from relevant test procedures and implemented in a Finite Element simulation of an …

Health Nexus: A Serious Game Prototype For Prevention And Treatment Of Obesity And Diabetes, Joseph C. Miller

Computational Modeling & Simulation Engineering Theses & Dissertations

Electronic games are a prevalent phenomenon of American culture and entertainment. Serious games are video games that take advantage of games' intrinsic entertaining and challenging characteristics for serious purposes, such as education, training, advertisement, and political campaigns. A significant number of serious games have been developed for a variety of diverse purposes. The last few years have witnessed the inception and growth of motion sensing technologies for games, including Nintendo Wii, Sony PlayStation Move, and Microsoft Kinect. These motion sensing technologies usually require game players' physical body movement in order to perform and achieve in the games, such as playing …

Trust And Reputation For Successful Software Self-Organisation, Pierpaolo Dondio, Jean Marc Seigneur

Books/Book Chapters

Abstract An increasing number of dynamic software evolution approaches is com- monly based on integrating or utilising new pieces of software. This requires reso- lution of issues such as ensuring awareness of newly available software pieces and selection of most appropriate software pieces to use. Other chapters in this book dis- cuss dynamic software evolution focusing primarily on awareness, integration and utilisation of new software pieces, paying less attention on how selection among different software pieces is made. The selection issue is quite important since in the increasingly dynamic software world quite a few new software pieces occur over time, …