Computational Engineering Commons^™

Computing Radiation Exchange, Jonathan L. Nutzati Fontaine

Doctoral Dissertations and Master's Theses

A computational tool to simulate thermal radiation between surfaces is developed. The output is verified against cases for which the analytical solutions are available. The tool can be used as a stand-alone program, or as an interactive module for CFD. In such an application the module would augment other heat transfer boundary conditions. The tool is demonstrated by post-processing surface temperature field data from a supersonic CFD calculation. The result is a net thermal radiation surface data field - the black body radiative effluxes as functions of temperature, less the integrated influxes multiplied by their geometric view factors from other …

Advancements And Challenges Towards A Collaborative Framework For 3d Tele-Immersive Social Networking, Davide Andrea Mauro, N. E. O’Connor, D. Monaghan, Marc Gowing, P. Fechteler, P. Eisert, J. Wall, E. Izquierdo, D. S. Alexiadis, P. Daras, R. Mekuria, P. Cesar

Computer Sciences and Electrical Engineering Faculty Research

Social experiences realized through teleconferencing systems are still quite different from face to face meetings. The awareness that we are online and in a, to some extent, lesser real world are preventing us from really engaging and enjoying the event. Several reasons account for these differences and have been identified. We think it is now time to bridge these gaps and propose inspiring and innovative solutions in order to provide realistic, believable and engaging online experiences. We present a distributed and scalable framework named REVERIE that faces these challenges and provides a mix of these solutions. Applications built on top …

A Multi-Configuration Display Methodology Incorporating Reflection For Real-Time Haptic-Interactive Virtual Environments, Mohammad F. Obeid

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a natural need for real-time min-or reflection in many interactive virtual reality applications to achieve visuo-haptic collocation through optical reflection. Its use, however, calls for adjustments to the original model since a mirror reverses image characteristics. This thesis introduces a design and implementation of a generic configuration component for virtual environments that adjusts image characteristics and haptic interfaces to accommodate various display setups while preserving the correct orientation and properties of the original models in the graphical scene. Four different but related approaches were developed for image connection and are compared and contrasted against primary criteria. The haptic …

A Framework For Realistic 3d Tele-Immersion, P Fechteler, A Hilsmann, P Eisert, S V. Broeck, C Stevens, J Wall, M Sanna, Davide Andrea Mauro, F Kuijk, R Mekuria, P Cesar

Computer Sciences and Electrical Engineering Faculty Research

Meeting, socializing and conversing online with a group of people using teleconferencing systems is still quite different from the experience of meeting face to face. We are abruptly aware that we are online and that the people we are engaging with are not in close proximity. Analogous to how talking on the telephone does not replicate the experience of talking in person. Several causes for these differences have been identified and we propose inspiring and innovative solutions to these hurdles in attempt to provide a more realistic, believable and engaging online conversational experience. We present the distributed and scalable framework …

0tter - 0g Tracking And Targeting Experiment In Real-Time, Brandon Bussjaeger

Computer Science and Software Engineering

No abstract provided.

Point Based Approximate Color Bleeding With Cuda, Nicholas D. Feeney

Master's Theses

Simulating light is a very computationally expensive proposition. There are a wide variety of global illumination algorithms that are implemented and used by major motion picture companies to render interesting and believable scenes. Every algorithm strives to find a balance between speed and accuracy. The Point Based Approximate Color Bleeding algorithm is one of the most widely used algorithms in the field today. The Point Based Approximate Color Bleeding(PBACB) global illumination algorithm is based on the central idea that the geometry and direct illumination of the scene can be approximated by using a point cloud representation. This point cloud representation …

Algorithms For Library-Based Microbial Source Tracking, Aldrin Montana

Master's Theses

Pyroprinting is a novel, library-based microbial source tracking method developed by the Biology department at Cal Poly, San Luis Obispo. This method consists of two parts: (1) a collection of bacterial fingerprints, called pyroprints, from known host species, and (2) a method for pyroprint comparison. Currently, Cal Poly Library of Pyroprints (CPLOP), a web-based database application, provides storage and analysis of over $10000$ pyroprints. This number is quickly growing as students and researchers continue to use pyroprinting for research. Biologists conducting research using pyroprinting rely on methods for partitioning collected bacterial isolates into bacterial strains. Clustering algorithms are commonly used …

Paris: A Parallel Rsa-Prime Inspection Tool, Joseph R. White

Master's Theses

Modern-day computer security relies heavily on cryptography as a means to protect the data that we have become increasingly reliant on. As the Internet becomes more ubiquitous, methods of security must be better than ever. Validation tools can be leveraged to help increase our confidence and accountability for methods we employ to secure our systems.

Security validation, however, can be difficult and time-consuming. As our computational ability increases, calculations that were once considered “hard” due to length of computation, can now be done in minutes. We are constantly increasing the size of our keys and attempting to make computations harder …

Individual Articulator's Contribution To Phoneme Production, Jun Wang, Jordan R. Green, Ashok Samal

School of Computing: Conference and Workshop Papers

Speech sounds are the result of coordinated movements of individual articulators. Understanding each articulator’s role in speech is fundamental not only for understanding how speech is produced, but also for optimizing speech assessments and treatments. In this paper, we studied the individual contributions of six articulators, tongue tip, tongue blade, tongue body front, tongue body back, upper lip, and lower lip to phoneme classification. A total of 3,838 vowel and consonant production samples were collected from eleven native English speakers. The results of speech movement classification using a support vector machine indicated that the tongue encoded significantly more information than …

Cooking Up The Optimal Baking Algorithm, Tony Burand, Michael Tetzlaff, Jacob Smith

Math and Computer Science Student Works

Many conventional rectangular baking pans have a problem in that they bake the corners of the batter faster than the rest of the pan. Circular baking pans eliminate this problem, but take up more space in the oven. We propose a solution that given weights for baking consistency and space efficiency based on the importance of each will provide the optimal baking pan shape. We have come up with an algorithm for sorting the pans of area A effectively and formed a model that describes the heat flow into the pan as well as the baking mix itself. The model …

Cooking Up The Optimal Baking Algorithm, Tony Burand, Michael Tetzlaff, Jacob Smith

Colloquy Undergraduate Research Journal

Many conventional rectangular baking pans have a problem in that they bake the corners of the batter faster than the rest of the pan. Circular baking pans eliminate this problem, but take up more space in the oven. We propose a solution that given weights for baking consistency and space efficiency based on the importance of each will provide the optimal baking pan shape. We have come up with an algorithm for sorting the pans of area A effectively and formed a model that describes the heat flow into the pan as well as the baking mix itself. The model …

Computation Of Heat Transfer In Turbine Rotor Blade Cooling Channels With Angled Rib Turbulators, Guy Austin Flynt

Masters Theses and Doctoral Dissertations

The effects of rotation and Reynolds number on heat transfer in rotating two-pass square and rectangular channels with smooth walls and walls with 45 degree angled and V-shaped rib turbulators were investigated numerically using an unstructured, incompressible, Reynolds-averaged Navier-Stokes flow solver. The influence of 45 degree angled ribs and channel orientation on the local Nusselt number ratios for leading and trailing surfaces in a two-pass square channel (AR=1) are compared to experimental data for Reynolds numbers from 5,000 to 25,000 and dimensionless rotation numbers from 0.0 to 0.118. The influence of V-shaped ribs and channel orientation on the local Nusselt …

Large-Scale Incidents Modeling And Network Simulation, Yichi Zhang

Civil & Environmental Engineering Theses & Dissertations

Traffic incidents on urban freeways are a major source of congestion and travel time uncertainty. In particular, large-scale incidents have longer durations and need more incident response resources. As such, large-scale incidents deserve more attention by practitioners and researchers. The objective of this study is to analyze large-scale incidents and explore their correlates and implications for traffic operations. An innovative analysis method, based on a 2008 incident data set from the Hampton Roads Traffic Operation Center (HRTOC) in Hampton Roads, Virginia was developed (N=59176). This study defined large-scale incidents as having a two hour minimum duration, based on guidance from …

Measuring The Value Of Conceptual Modeling A Return On Investment (Roi) Analysis, Jeffrey Alan Brelsford

Computational Modeling & Simulation Engineering Theses & Dissertations

This thesis presents a method for calculating the return on investment (ROI) of conceptual modeling. Conceptual modeling as it relates to Modeling and Simulation (M&S) studies is a process that abstracts a model of a real or proposed system to be subsequently used for developing computer models. The conceptual modeling process is a critical constituent in an M&S project because it produces the central reference for building the computer model. Computer models require formal logic to carry out procedures, and consistent arguments in formal logic are crucial for the model to be useful. Not only does formal logic provide the …

A Survey Of Systems For Predicting Stock Market Movements, Combining Market Indicators And Machine Learning Classifiers, Jeffrey Allan Caley

Dissertations and Theses

In this work, we propose and investigate a series of methods to predict stock market movements. These methods use stock market technical and macroeconomic indicators as inputs into different machine learning classifiers. The objective is to survey existing domain knowledge, and combine multiple techniques into one method to predict daily market movements for stocks. Approaches using nearest neighbor classification, support vector machine classification, K-means classification, principal component analysis and genetic algorithms for feature reduction and redefining the classification rule were explored. Ten stocks, 9 companies and 1 index, were used to evaluate each iteration of the trading method. The classification …

Audio Convolution On Gpus: A Follow-Up, Davide Andrea Mauro

Computer Sciences and Electrical Engineering Faculty Research

This paper focuses on the use of GPGPU (General- Purpose computing on Graphics Processing Units) for audio processing. This is a promising approach to problems where a high parallelization of tasks is desirable. Within the context of binaural spatialization we will develop a convolution engine having in mind both offine and real-time scenarios, and the support for multiple sound sources. Details on implementations and strategies used with both dominant technologies, namely CUDA and OpenCL, will be presented highlighting both advantages and issues. Comparisons between this approach and typical CPU implementations will be presented as well as between frequency (FFT) and …

Argumentation Theory In Health Care, Luca Longo, Bridget Kane, Lucy Hederman

Books/Book Chapters

Argumentation theory (AT) has been gaining momentum in the health care arena thanks to its intuitive and modular way of aggregating clinical evidence and taking rational decisions. The basic principles of argumentation theory are described and demonstrated in the breast cancer recurrence problem. It is shown how to represent available clinical evidence in arguments, how to define defeat relations among them and how to create a formal argumentation framework. Argumentation semantics are then applied over the built framework to compute arguments justification status. It is demonstrated how this process can enhance the clinician decision-making process. A encouraging predictive capacity is …

Distal Placement Of An End-To-Side Bypass Graft Anastomosis: A 3d Computational Study, John Di Cicco, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

A three-dimensional (3D) computational fluid dynamics study of shear rates around distal end-to-side anastomoses has been conducted. Three 51% and three 75% cross-sectional area-reduced 6 mm cylinders were modeled each with a bypass cylinder attached at a 30-degree angle at different placements distal to the constriction. Steady, incompressible, Newtonian blood flow was assumed, and the full Reynolds-averaged Navier-Stokes equations, turbulent kinetic energy, and specific dissipation rate equations were solved on a locally structured multiblock mesh with hexahedral elements. Consequently, distal placement of an end-to-side bypass graft anastomosis was found to have an influence on the shear rate magnitudes. For the …

Argumentation Theory For Decision Support In Health-Care: A Comparison With Machine Learning, Luca Longo, Lucy Hederman

Books/Book Chapters

This study investigates role of defeasible reasoning and argumentation theory for decision-support in the health-care sector. The main objective is to support clinicians with a tool for taking plausible and rational medical decisions that can be better justified and explained. The basic principles of argumentation theory are described and demonstrated in a well known health scenario: the breast cancer recurrence problem. It is shown how to translate clinical evidence in the form of arguments, how to define defeat relations among them and how to create a formal argumentation framework. Acceptability semantics are then applied over this framework to compute arguments …

Architecture--Performance Interrelationship Analysis In Single/Multiple Cpu/Gpu Computing Systems: Application To Composite Process Flow Modeling, Richard Harrison Haney

Dissertations

Current developments in computing have shown the advantage of using one or more Graphic Processing Units (GPU) to boost the performance of many computationally intensive applications but there are still limits to these GPU-enhanced systems. The major factors that contribute to the limitations of GPU(s) for High Performance Computing (HPC) can be categorized as hardware and software oriented in nature. Understanding how these factors affect performance is essential to develop efficient and robust applications codes that employ one or more GPU devices as powerful co-processors for HPC computational modeling. The present work analyzes and understands the intrinsic interrelationship of both …

Computational Material Modeling For Mechanical Properties Prediction And A Methodology For Mie Gruneisen Equation Of State Characterization Via Molecular/Nano Scale Cementitious Material Constituents, Ahmed Mohamed

Dissertations

Cementitious materials have complex hierarchical structures with random features that range from nanometer (nm) to millimeter (mm) scale. Processes occurring at the nanometer scale affect the performance at larger length scales. The present work employs molecular dynamics (MD) simulations as the computational modeling methodology to predict mechanical properties for both hydrated and unhydrated cementitious materials at the molecular/nano scale level. A detailed study on the effect of increasing MD simulation cell size, dynamics time duration on the predicted mechanical properties was performed. Further studies focused on understanding the effect of higher thermodynamic pressure states on predicted …

Two-Dimensional Hydrodynamic Modeling Of Two-Phase Flow For Understanding Geyser Phenomena In Urban Stormwater System, Zhiyu S. Shao

Theses and Dissertations--Civil Engineering

During intense rain events a stormwater system can fill rapidly and undergo a transition from open channel flow to pressurized flow. This transition can create large discrete pockets of trapped air in the system. These pockets are pressurized in the horizontal reaches of the system and then are released through vertical vents. In extreme cases, the transition and release of air pockets can create a geyser feature.

The current models are inadequate for simulating mixed flows with complicated air-water interactions, such as geysers. Additionally, the simulation of air escaping in the vertical dropshaft is greatly simplified, or completely ignored, in …

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 …

Reference Modelling In Support Of M&S—Foundations And Applications, Andreas Tolk, Saikou Diallo, Jose Padilla, H. Herencia-Zapana

Engineering Management & Systems Engineering Faculty Publications

Whether by design or by practice, systems engineering (SE) processes are used more and more often in Modeling and Simulation (M&S). While the two disciplines are very close, there are some differences that must be taken into account in order to successfully reuse practices from one community to another. In this paper, we introduce the M&S System Development Framework (MS-SDF) that unifies SE and M&S processes. The MS-SDF comprises the SE processes of requirements capture, conceptual modelling, and verification and validation (V&V), and extends them to M&S. We use model theory as a deductive apparatus in order to develop the …

Rational Approximation For The One-Dimensional Bratu Equation, Moustafa A. Soliman

Chemical Engineering

The solution of the one dimensional planar Bratu equation is characterized by having two branches. The two branches meet at a limit point that can be obtained through the solution of an eigen-relation. In this paper a transformation is introduced to transform this highly non-linear problem to a linear one. Rational expressions are given for the solution of the Bratu equation and the limit point. This is done using collocation and perturbation techniques.

Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use the lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales, to simplify the analysis of coating film dynamics. We study the dynamics of coating thin films on horizontal stationary and rotating cylinders in general, and when the effect of van der Waals forces is significant. A computer code based on the method of orthogonal collocation is developed and is used for the study of the instabilities of coating thin film flow on cylinders to identify conditions of stable operation. For stationary cylinders, the equations are symmetric and the …

Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use Lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales to simplify the analysis of thin film dynamics. We study the dynamics of evaporating thin liquid films on an inclined plane, where the effect of van der Waal forces is significant. The numerical solution of the evolution equation is carried out using the method of orthogonal collocation and is used for the study of the instabilities of evaporating thin film to identify conditions for efficient operation. For symmetric cases where the plane is horizontal, a two spline collocation second …

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 …

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 …