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Computational Engineering Commons

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2017

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Articles 1 - 30 of 74

Full-Text Articles in Computational Engineering

An Application Of M-Matrices To Preserve Bounded Positive Solutions To The Evolution Equations Of Biofilm Models, Richard S. Landry Jr. Dec 2017

An Application Of M-Matrices To Preserve Bounded Positive Solutions To The Evolution Equations Of Biofilm Models, Richard S. Landry Jr.

University of New Orleans Theses and Dissertations

In this work, we design a linear, two step implicit finite difference method to approximate the solutions of a biological system that describes the interaction between a microbial colony and a surrounding substrate. Three separate models are analyzed, all of which can be described as systems of partial differential equations (PDE)s with nonlinear diffusion and reaction, where the biological colony grows and decays based on the substrate bioavailability. The systems under investigation are all complex models describing the dynamics of biological films. In view of the difficulties to calculate analytical solutions of the models, we design here a numerical ...


Multiphase Flow Modeling For Design And Optimization Of A Novel Down-Flow Bubble Column, Mutharasu Lalitha Chockalingam Dec 2017

Multiphase Flow Modeling For Design And Optimization Of A Novel Down-Flow Bubble Column, Mutharasu Lalitha Chockalingam

LSU Doctoral Dissertations

The application of the Euler-Euler framework based Computational Fluid Dynamics (CFD) models for simulating the two-phase gas-liquid bubbly flow in down-flow bubble columns is discussed in detail. Emphasis is given towards the modelling and design optimization of a novel down-flow bubble column. The design features of this novel down-flow bubble column and its advantages over a conventional Plunging Jet down-flow bubble column are discussed briefly. Then, some of the present challenges in simulating a conventional Plunging Jet down-flow bubble column in the Euler-Euler framework is highlighted, and a sigmoid function based drag modification function is implemented to overcome those challenges ...


Real Time And High Fidelity Quadcopter Tracking System, Tyler Mckay Hall Dec 2017

Real Time And High Fidelity Quadcopter Tracking System, Tyler Mckay Hall

Computer Engineering

This project was conceived as a desired to have an affordable, flexible and physically compact tracking system for high accuracy spatial and orientation tracking. Specifically, this implementation is focused on providing a low cost motion capture system for future research. It is a tool to enable the further creation of systems that would require the use of accurate placement of landing pads, payload acquires and delivery. This system will provide the quadcopter platform a coordinate system that can be used in addition to GPS.

Field research with quadcopter manufacturers, photographers, agriculture and research organizations were contact and interviewed for information ...


Whitespace Exploration, Jason Lloyd Daniel Dec 2017

Whitespace Exploration, Jason Lloyd Daniel

Master's Theses and Project Reports

As engineering systems grow in complexity so too must the design tools that we use evolve and allow for decision makers to efficiently ask questions of their model and obtain meaningful answers. The process of whitespace exploration has recently been developed to aid in engineering design and provide insight into a design space where traditional design exploration methods may fail. In an effort to further the research and development of whitespace exploration algorithms, a software package called Thalia has been created to allow for automated data collection and experimentation with the whitespace exploration methodology.

In this work, whitespace exploration is ...


State-Based Peridynamic Particle Method, Siavash Nikravesh Kazeroni Nov 2017

State-Based Peridynamic Particle Method, Siavash Nikravesh Kazeroni

Civil Engineering ETDs

In this study, a novel discrete Peridynamics framework called the “State-Based Peridynamic Particle Model (SPPM)” is introduced. In this approach, a solid body is simulated by neither solving differential equations nor integral equations; instead, the simulation is accomplished by directly solving discrete systems of equations using finite summations. SPPM is formulated for a random distribution of particles, hence, it can be considered as a meshfree method. The assumptions of continuity and homogeneity are not necessary for this approach. The SPPM is a generalization of the “State-Based Peridynamic Lattice Model (SPLM)”. In the SPLM formulation, for sake of simplicity and computational ...


A Smart Internet Of Things (Iot) Prototype For Accurate People Counting Towards Energy Efficient Buildings, Qian Huang, Kane Rodriguez, Chao Lu Nov 2017

A Smart Internet Of Things (Iot) Prototype For Accurate People Counting Towards Energy Efficient Buildings, Qian Huang, Kane Rodriguez, Chao Lu

ASA Multidisciplinary Research Symposium

According to the U.S. Department of Energy, 30% of the energy used in commercial buildings is wasted. If the number of humans in each pre-determined thermal zone is aware, a building automation system (BAS) is able to intelligently adjust HVAC operation for each thermal zone to provide “just-enough” heating, cooling and ventilation to building users. Therefore, a people counting device that can be widely deployed with low price and failure rate, small form-factor, good usability, and conserved user privacy is highly desirable. Existing room occupancy detection sensors (e.g., passive infrared, camera, acoustic, RFID, CO2) cannot meet all ...


A High Quality, Eulerian 3d Fluid Solver In C++, Lejon Anthony Mcgowan Nov 2017

A High Quality, Eulerian 3d Fluid Solver In C++, Lejon Anthony Mcgowan

Computer Science and Software Engineering

Fluids are a part of everyday life, yet are one of the hardest elements to properly render in computer graphics. Water is the most obvious entity when thinking of what a fluid simulation can achieve (and it is indeed the focus of this project), but many other aspects of nature, like fog, clouds, and particle effects. Real-time graphics like video games employ many heuristics to approximate these effects, but large-scale renderers aim to simulate these effects as closely as possible.

In this project, I wish to achieve effects of the latter nature. Using the Eulerian technique of discrete grids, I ...


Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward Oct 2017

Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward

Nicholas Hayward

Software metrics are a critical tool which provide continuous insight to products and processes and help build reliable software in mission critical environments. Using software metrics we can perform calculations that help assess the effectiveness of the underlying software or process. The two types of metrics relevant to our work is complexity metrics and in-process metrics. Complexity metrics tend to focus on intrinsic code properties like code complexity. In-process metrics focus on a higher-level view of software quality, measuring information that can provide insight into the underlying software development process.

Our aim is to develop and evaluate a metrics dashboard ...


Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward Oct 2017

Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward

Konstantin Läufer

Software metrics are a critical tool which provide continuous insight to products and processes and help build reliable software in mission critical environments. Using software metrics we can perform calculations that help assess the effectiveness of the underlying software or process. The two types of metrics relevant to our work is complexity metrics and in-process metrics. Complexity metrics tend to focus on intrinsic code properties like code complexity. In-process metrics focus on a higher-level view of software quality, measuring information that can provide insight into the underlying software development process.

Our aim is to develop and evaluate a metrics dashboard ...


Scalable Data Structure To Compress Next-Generation Sequencing Files And Its Application To Compressive Genomics, Sandino Vargas-Perez, Fahad Saeed Oct 2017

Scalable Data Structure To Compress Next-Generation Sequencing Files And Its Application To Compressive Genomics, Sandino Vargas-Perez, Fahad Saeed

Parallel Computing and Data Science Lab Technical Reports

It is now possible to compress and decompress large-scale Next-Generation Sequencing files taking advantage of high-performance computing techniques. To this end, we have recently introduced a scalable hybrid parallel algorithm, called phyNGSC, which allows fast compression as well as decompression of big FASTQ datasets using distributed and shared memory programming models via MPI and OpenMP. In this paper we present the design and implementation of a novel parallel data structure which lessens the dependency on decompression and facilitates the handling of DNA sequences in their compressed state using fine-grained decompression in a technique that is identified as in compresso ...


Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Usman Tariq, Umer Cheema, Fahad Saeed Oct 2017

Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Usman Tariq, Umer Cheema, Fahad Saeed

Parallel Computing and Data Science Lab Technical Reports

Energy efficiency is a crucial problem in data centers where big data is generally represented by directed or undirected graphs. Analysis of this big data graph is challenging due to volume and velocity of the data as well as irregular memory access patterns. Graph sampling is one of the most effective ways to reduce the size of graph while maintaining crucial characteristics. In this paper we present design and implementation of an FPGA based graph sampling method which is both time- and energy-efficient. This is in contrast to existing parallel approaches which include memory-distributed clusters, multicore and GPUs. Our ...


Streaming Vr For Immersion: Quality Aspects Of Compressed Spatial Audio, Miroslaw Narbutt, Sean O’Leary, Andrew Allen, Jan Skoglund, Andrew Hines Oct 2017

Streaming Vr For Immersion: Quality Aspects Of Compressed Spatial Audio, Miroslaw Narbutt, Sean O’Leary, Andrew Allen, Jan Skoglund, Andrew Hines

Conference papers

Delivering a 360-degree soundscape that matches full sphere visuals is an essential aspect of immersive VR. Ambisonics is a full sphere surround sound technique that takes into account the azimuth and elevation of sound sources, portraying source location above and below as well as around the horizontal plane of the listener. In contrast to channel-based methods, ambisonics representation offers the advantage of being independent of a specific loudspeaker set-up. Streaming ambisonics over networks requires efficient encoding techniques that compress the raw audio content without compromising quality of experience (QoE). This work investigates the effect of audio channel compression via the ...


Feature Extraction And Parallel Visualization For Large-Scale Scientific Data, Lina Yu Sep 2017

Feature Extraction And Parallel Visualization For Large-Scale Scientific Data, Lina Yu

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

Advanced computing and sensing technologies enable scientists to study natural and physical phenomena with unprecedented precision, resulting in an explosive growth of data. The unprecedented amounts of data generated from large scientific simulations impose a grand challenge in data analytics and visualization due to the fact that data are too massive for transferring, storing, and processing.

This dissertation makes the first contribution to the design of novel transfer functions and application-aware data replacement policy to facilitate feature classification on highly parallel distributed systems. We design novel transfer functions that advance the classification of continuously changed volume data by combining the ...


Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos Aug 2017

Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos

Sakdirat Kaewunruen

Safety is the first priority in operating transportation and transit systems. The public and customers rely on operators to assure them the reliable and safe day-to-day uses of public transports. However, based on recent factual evidences, extreme physical and cyber threats are no longer uncommon and these unpreventable measures are even more dangerous to the public’s daily lives. Such clear examples are the terrorist attacks in Saint Petersburg in 2017, in London in 2017, in Stockholm in 2017, in Brussels in 2016, in Nice in 2016, and so many more. These examples have one thing in common. The transportation ...


Modelling Of Convective Heat Transfer In Porous Media, Jeremy Vu Aug 2017

Modelling Of Convective Heat Transfer In Porous Media, Jeremy Vu

Electronic Thesis and Dissertation Repository

This thesis details the process taken for the computational modelling of convective heat transfer in porous media. An in-house porous continuum model is modified to improve the prediction of heat transfer which is obtained when forcing fluid through porous blocks heated from one side. The results are compared to those obtained from CFD simulations performed using commercial software. Results indicated that a modification to conductivity the solid phase of the porous material must be included due to the tortuosity, or the complexity of the solid structure. Previously the tortuosity was not considered when calculating the effective solid phase conductivity.The ...


On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, Ronald J. Giardina Jr Aug 2017

On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, Ronald J. Giardina Jr

University of New Orleans Theses and Dissertations

In this thesis the Ramberg-Osgood nonlinear model for describing the behavior of many different materials is investigated. A brief overview of the model as it is currently used in the literature is undertaken and several misunderstandings and possible pitfalls in its application is pointed out, especially as it pertains to more recent approaches to finding solutions involving the model. There is an investigation of the displacement of a cantilever beam under a combined loading consisting of a distributed load across the entire length of the beam and a point load at its end and new solutions to this problem are ...


Web-Based Interactive Social Media Visual Analytics, Diego Rodríguez-Baquero, Jiawei Zhang, David S. Ebert, Sorin A. Matei Aug 2017

Web-Based Interactive Social Media Visual Analytics, Diego Rodríguez-Baquero, Jiawei Zhang, David S. Ebert, Sorin A. Matei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Real-time social media platforms enable quick information broadcasting and response during disasters and emergencies. Analyzing the massive amount of generated data to understand the human behavior requires data collection and acquisition, parsing, filtering, augmentation, processing, and representation. Visual analytics approaches allow decision makers to observe trends and abnormalities, correlate them with other variables and gain invaluable insight into these situations. In this paper, we propose a set of visual analytic tools for analyzing and understanding real-time social media data in times of crisis and emergency situations. First, we model the degree of risk of individuals’ movement based on evacuation zones ...


Visually Analyzing The Impacts Of Essential Air Service Funding Decisions, Rohan Kashuka, Chittayong Surakitbanharn, Calvin Yau, David S. Ebert Aug 2017

Visually Analyzing The Impacts Of Essential Air Service Funding Decisions, Rohan Kashuka, Chittayong Surakitbanharn, Calvin Yau, David S. Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

Essential Air Service (EAS) is a U.S. government subsidy program which ensures maintenance of commercial airline services in small deregulated communities. The program’s budget currently is around $250 million annually, which is used as subsidy for airlines to maintain a minimal level of scheduled air service in relatively smaller airports. It is evident that 2% of the FAA budget is being spent to maintain air service in smaller communities, but there is not enough evidence to prove that all the current decisions made by Congress about EAS are advantageous. To understand these decisions, 15 years of data produced ...


On Accelerating Source Code Analysis At Massive Scale, Ganesha Upadhyaya, Hridesh Rajan Aug 2017

On Accelerating Source Code Analysis At Massive Scale, Ganesha Upadhyaya, Hridesh Rajan

Computer Science Technical Reports

Encouraged by the success of data-driven software engineering (SE) techniques that have found numerous applications e.g. in defect prediction, specification inference, etc, the demand for mining and analyzing source code repositories at scale has significantly increased. However, analyzing source code at scale remains expensive to the extent that data-driven solutions to certain SE problems are beyond our reach today. Extant techniques have focussed on leveraging distributed computing to solve this problem, but with a concomitant increase in computational resource needs. This work proposes a technique that reduces the amount of computation performed by the ultra-large-scale source code mining task ...


Physical Information Incorporated Clustering Techniques And Their Applications In Transportation Information System, Yang Zhang Aug 2017

Physical Information Incorporated Clustering Techniques And Their Applications In Transportation Information System, Yang Zhang

Doctoral Dissertations

Massive data from different sources are becoming available in transportation field, and spurring new research on utilizing these data to nurture new intelligent transportation information systems. Clustering algorithms are among the methods that are being applied to the domain but facing challenges. Classical clustering algorithms work fine with \point" based data, which are homogeneous and have no extra constraints. Data in transportation are sometimes involved with specific geometric shapes, have underlying constraints, and can be heterogeneous. There has been no clustering algorithm dedicated to these situations.

In this dissertation, we re-examine the mathematical foundation and underlying philosophy of hierarchical, density ...


Evaluation And Enhancement Of Clean Energy Systems: Analytical, Computational And Experimental Study Of Solar And Nuclear Cycles, Nima Fathi Jul 2017

Evaluation And Enhancement Of Clean Energy Systems: Analytical, Computational And Experimental Study Of Solar And Nuclear Cycles, Nima Fathi

Mechanical Engineering ETDs

Clean (and specifically renewable) energy is steadily improving its global share. However, finite availability of fossil fuels and the growing effects of climate change make it an urgent priority to convince the industry and governments to incentivize investment in the renewable energy field and to make it more attractive by decreasing the capital cost. Until recently, uncertainties in funding limited renewable energy development, especially in the US. That limitation has been one of the barriers to progress. Another limitation of many renewable energy systems is the variability in their output, which makes them unsuitable for baseline power production. Therefore, fossil ...


Ion Size Effects On The Properties Of Charge Regulating Electric Double Layers, Divya Jyoti Prakash Jul 2017

Ion Size Effects On The Properties Of Charge Regulating Electric Double Layers, Divya Jyoti Prakash

Nanoscience and Microsystems ETDs

The behavior of charged interfaces formed in various systems like colloidal solution, fuel cells, battery, electro-deposition, catalysis is governed by the properties of electrical double layer(EDL). Civilized model with charge regulation boundary condition determined by thermodynamic equilibrium at the interface has been used to model electrical double layer and shows that size of the solvent plays a critical role in characterizing the properties of EDL using classical density functional theory.This thesis investigates the impact of ion size in electrolyte solutions on the electrical double layer formed at the interface using a similar model. It is found that ion ...


Interactive Visualization Of Multimodal Brain Connectivity: Applications In Clinical And Cognitive Neuroscience, Saeed Mahdizadeh Bakhshmand Jul 2017

Interactive Visualization Of Multimodal Brain Connectivity: Applications In Clinical And Cognitive Neuroscience, Saeed Mahdizadeh Bakhshmand

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) has become a readily available prognostic and diagnostic method, providing invaluable information for the clinical treatment of neurological diseases. Multimodal neuroimaging allows integration of complementary data from various aspects such as functional and anatomical properties; thus, it has the potential to overcome the limitations of each individual modality. Specifically, functional and diffusion MRI are two non-invasive neuroimaging techniques customized to capture brain activity and microstructural properties, respectively. Data from these two modalities is inherently complex, and interactive visualization can assist with data comprehension.

The current thesis presents the design, development, and validation of visualization and computation ...


Iota: Internet Of Things Assistant, Brandon M. Okumura Jul 2017

Iota: Internet Of Things Assistant, Brandon M. Okumura

Master's Theses and Project Reports

The Internet of Things is the networking of electronic devices, or “Things”, that enables them to collect and share data, as well as interact with their physical surround- ings. Analyzing this collected data allows us to make smarter economic decisions. These interconnected networks are usually driven by low-powered micro-controllers or cheap CPUs that are designed to function optimally with very little hardware. As scale and computational requirements increase, these micro-controllers are unable to grow without being physically replaced.

This thesis proposes a system, IoTA, that assists the Internet of Things by pro- viding a shared computational resource for endpoint devices ...


The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim Jul 2017

The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

Computational modeling of joints is used to investigate the effect of injuries, to plan surgeries, and to answer questions about joints that cannot be answered experimentally. Existing models of the ankle joint are moving toward being able to model specific patients, however, they do not include all of the anatomy (e.g., bones and/or ligaments) and have restrictive boundary conditions. These simplification in anatomy are made to minimize pre-processing and computation time. Because biomechanical modeling is increasingly focused on the implementation of patient specific cases, the effects of including more anatomical structures and determining how they affect the model ...


A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Professor Jun 2017

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Professor

Conference papers

In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. The ...


High Fidelity Cfd Modeling Of Natural Ventilation In A Solar House, Mirka Deza, Baskar Ganapathysubramanian, Shan He, Ulrike Passe Jun 2017

High Fidelity Cfd Modeling Of Natural Ventilation In A Solar House, Mirka Deza, Baskar Ganapathysubramanian, Shan He, Ulrike Passe

Baskar Ganapathysubramanian

Natural ventilation is an important factor in the design of sustainable buildings; it has the potential to improve air quality, while providing thermal comfort at reduced energy costs. Computational fluid dynamics (CFD) simulations provide comprehensive information on the internal flow pattern and can be used as a design tool. The present work offers insight of natural ventilation in a fully functional building, namely, the solar facility Interlock House in Iowa. Ventilation in the house is studied during summer months with some of its furniture included. The results show quantitative agreement between numerical simulations and experiments of vertical temperature profiles for ...


Ultrasound Scatter In Heterogeneous 3d Microstructures, Brady Engle, Ronald A. Roberts, Robert Grandin Jun 2017

Ultrasound Scatter In Heterogeneous 3d Microstructures, Brady Engle, Ronald A. Roberts, Robert Grandin

Robert Grandin

This paper reports on a computational study of ultrasound propagation in heterogeneous metal microstructures. Random spatial fluctuations in elastic properties over a range of length scales relative to ultrasound wavelength can give rise to scatter-induced attenuation, backscatter noise, and phase front aberration. It is of interest to quantify the dependence of these phenomena on the microstructure parameters, for the purpose of quantifying deleterious consequences on flaw detectability, and for the purpose of material characterization. Valuable tools for estimation of microstructure parameters (e.g. grain size) through analysis of ultrasound backscatter have been developed based on approximate weak-scattering models. While useful ...


Surrogate Modeling Of Ultrasonic Testing Simulations Using Variable-Fidelity Models And Data-Driven Methods, Robert Grandin, Leifur Leifsson Jun 2017

Surrogate Modeling Of Ultrasonic Testing Simulations Using Variable-Fidelity Models And Data-Driven Methods, Robert Grandin, Leifur Leifsson

Robert Grandin

Ultrasonic testing (UT) is used to detect internal flaws in materials or to characterize material properties [1]. Computational simulations are an important part of the UT process. Having fast surrogate models for ultrasonic testing (UT) simulations is key for inverse analysis and model-assisted probability of detection (MAPOD) in the field of nondestructive evaluation. In fact, it is impractical to perform the aforementioned tasks in a timely manner using current simulation models directly. Fast surrogate models can make these processes computationally tractable. This paper presents investigations of using surrogate modeling techniques to create fast approximate models of UT simulator responses. In ...


Validation Of Utsim2, A New Ultrasonic Simulation Package, Robert Grandin, Timothy Gray Jun 2017

Validation Of Utsim2, A New Ultrasonic Simulation Package, Robert Grandin, Timothy Gray

Robert Grandin

The Center for NDE (CNDE) at Iowa State University has a long history of developing physics models for NDE and packaging these models into simulation tools which make the modeling capabilities accessible to CNDE’s industrial sponsors. Recent work at CNDE has led to the development of a new ultrasonic simulation package, UTSim2, which aims to continue this tradition of supporting industrial application of CNDE models. In order to meet this goal, UTSim2 has been designed as an extensible software package which can support previously-developed physics models as well as future models yet to be developed. Initial work has focused ...