Computational Engineering Commons^™

A Stratified Turbulence Formulation And A Turbulent Inflow Boundary Condition For Large-Eddy Simulation Of Complex Terrain Winds, Clancy Umphrey

Boise State University Theses and Dissertations

There has been an increased interest to forecast winds over complex terrain under realistic stability conditions using spatial resolutions that are much finer than the current practice. This goal is realizable thanks to the computational power of graphics processing units (GPUs). This thesis investigates an immersed boundary (IB) formulation and a turbulent inflow boundary condition within a multi-GPU parallel incompressible wind solver. Katabatic flows over a sloped complex terrain surface under stable stratification remain to be one of the least understood subjects in atmospheric turbulence. Prandtl’s analytical solution for laminar katabatic flow is used to develop an IB formulation to …

A Numerical Investigation Of A Solidification Model For Snow Micro-Structure Metamorphosis, Micah Johnson

Boise State University Theses and Dissertations

Understanding the way snow changes during environmental events has wide spread benefits ranging from avalanche prediction to water conservation. Snow on a micro-structural level constantly changes from the moment it forms. Snow metamorphosis is driven by the transport of water vapor. Thus far it has only been investigated as a pure diffusion process in dry snow, despite observations that suggest that natural convection may have a role in the heat and mass transport in snow packs. This thesis research numerically explores the role of transport processes in the context of snow metamorphism. An existing solidification model is reformulated to simulate …

On The Selection Of A Good Shape Parameter For Rbf Approximation And Its Application For Solving Pdes, Lei-Hsin Kuo

Dissertations

Meshless methods utilizing Radial Basis Functions~(RBFs) are a numerical method that require no mesh connections within the computational domain. They are useful for solving numerous real-world engineering problems. Over the past decades, after the 1970s, several RBFs have been developed and successfully applied to recover unknown functions and to solve Partial Differential Equations (PDEs).
However, some RBFs, such as Multiquadratic (MQ), Gaussian (GA), and Matern functions, contain a free variable, the shape parameter, c. Because c exerts a strong influence on the accuracy of numerical solutions, much effort has been devoted to developing methods for determining shape parameters which provide …

A Modified Rank Ordered Logit Model To Analyze Injury Severity Of Occupants In Multi-Vehicle Crashes, Shelley Bogue

Civil & Environmental Engineering Theses & Dissertations

Research on methodological approaches to model injury severity has become important in order to prevent crash fatalities. Roadways have always been dangerous, with significant congestion and uncontrollable variables, such as weather, coupled with road users' decisions including seat belt and alcohol/drug use. These decisions can influence the severity of injuries sustained by vehicle occupants in the event of a crash. Few studies have examined the potential impacts of comprehensive roadway user injury severity profiles of all occupants ( drivers as well as passengers) in all vehicles involved in a crash. The focus of past studies has been on examining the …

Accuracy Comparison Of Numerical Integration Algorithms For Real-Time Hybrid Simulations, Ganesh Anant Reddy

Civil & Environmental Engineering Theses & Dissertations

The use of accurate numerical integration algorithms is one of the key factors for a successful real-time hybrid simulation (RTHS). In RTHSs, explicit integration algorithms are preferred more than implicit methods since all calculations need to be completed within a given time step during simulation. Explicit methods require the use of effective stiffness and damping for experimental substructures, which are incorporated into the calculation of the integration parameters. In general, those values that are greater than the expected stiffness and damping of the experimental substructure are used to ensure the stability of simulation. If a rate-dependent and nonlinear experimental substructure …

Classification Of Digital Communication Signal Modulation Schemes In Multipath Environments Using Higher Order Statistics, Meena Sreekantamurthy

Electrical & Computer Engineering Theses & Dissertations

Automatic identification and classification of modulation schemes in communication signals and decoding of information from the captured signals has assumed great importance recently in the wireless communication industry. Advancements in communications have introduced a large variety of modulation schemes in the transmitted signals; consequently, reliable detection of the modulation scheme in the intercepted signal has become an important issue in communications. It is the aim of this thesis to address this issue of reliable detection. Therefore, this research is focused on modeling and simulation of an automatic modulation classifier and, in particular, on the development of algorithms to use higher …

Computational Fluid Dynamics Study Of Balloon System Tethered To A Stratosail, Jayakanth Loganathan, Kian-Meng Lim, Heow Pueh Lee, Boo Cheong Khoo

2017 Academic High Altitude Conference

In this paper, we present a numerical study of a stratospheric balloon system tethered to a passive device, known as the Stratosail, for station-keeping operation. For scientific applications, stratospheric balloons that operate at altitudes between 15 and 20 km will need to maintain station over a fixed point above the earth for a prescribed period of time. This is a challenging problem due to the limitation of payloads and lack of an energy source. The present study uses computational fluid dynamics (CFD) simulations to analyze the drift velocity of such a balloon-Stratosail system under typical wind conditions in the stratosphere. …

Cooperative 3-D Map Generation Using Multiple Uavs, Andrew Erik Lawson

University Scholar Projects

This report aims to demonstrate the feasibility of building a global 3-D map from multiple UAV robots in a GPS-denied, indoor environment. Presented are the design of each robot and the reasoning behind choosing its hardware and software components, the process in which a single robot obtains a individual 3-D map entirely onboard, and lastly how the mapping concept is extended to multiple robotic agents to form a global 3-D map using a centralized server. In the latter section, this report focuses on two algorithms, Online Mapping and Map Fusion, developed to facilitate the cooperative approach. A limited selection …

What Is The Right Context For An Engineering Problem: Finding Such A Context Is Np-Hard, Martine Ceberio, Vladik Kreinovich, Hung T. Nguyen, Songsak Sriboonchitta, Rujira Ouncharoen

Departmental Technical Reports (CS)

In the general case, most computational engineering problems are NP-hard. So, to make the problem feasible, it is important to restrict this problem. Ideally, we should use the most general context in which the problem is still feasible. In this paper, we prove that finding such most general context is itself an NP-hard problem. Since it is not possible to find the appropriate context by utilizing some algorithm, it is therefore necessary to be creative -- i.e., to use some computational intelligence techniques. On three examples, we show how such techniques can help us come up with the appropriate context. …

Semi-Automated Test Generation With Spest, Adam Mozek

Computer Science and Software Engineering

Automated black box test generation is a useful tool for developers that allows them to

quickly generate a large number of tests with a wide range of values tested. The current most

popular tool for black box test generation in Java, JML, is lacking in a number of features.

SPEST aims to improve upon existing tools, and provide a black box test generation tool that

can create human readable tests from simple pre and post conditions added as comments to

the Java source code.

Three-Dimensional Ideal Gas Reference State Based Energy Function, Avdesh Mishra

LSU New Orleans Theses and Dissertations

Energy functions are found to be a key of protein structure prediction. In this work, we propose a novel 3-dimensional energy function based on hydrophobic-hydrophilic properties of amino acid where we consider at least three different possible interaction of amino acid in a 3-dimensional sphere categorized as hydrophilic versus hydrophilic, hydrophobic versus hydrophobic and hydrophobic versus hydrophilic. Each of these interactions are governed by a 3-dimensional parameter alpha used to model the interaction and 3-dimensional parameter beta used to model weight of contribution. We use Genetic Algorithm (GA) to optimize the value of alpha, beta and Z-score. We obtain three …

Adaptive Motion Pooling And Diffusion For Optical Flow, Naga Venkata Kartheek Medathati, Pierre Kornprobst, Guillaume Masson, Manuela Chessa, Fabio Solari

MODVIS Workshop

We study the impact of local context of an image (contrast and 2D structure) on spatial motion integration by MT neurons. To do so, we revisited the seminal work by Heeger and Simoncelli (HS) [4] using spatio-temporal filters to estimate optical flow from V1-MT feedforward interactions. However, the HS model has difficulties to deal with several problems encountered in real scenes (e.g., blank wall problem and motion discontinuities). Here, we propose to extend the HS model with adaptive processing by focussing on the role of local context indicative of the local velocity estimates reliability. We set a network structure representative …

Evoking History Through Sound: A Soundscape Concept For Ghosts Of The Horseshoe, Connor Patrick Bain

Senior Theses

Sound has always been treated as a second citizen in our society. Our society places so much emphasis on the visual that hearing, a sense that we cannot ever shut out from our minds, is taken for granted. This thesis argues that you can never ignore sound and proposes a design cycle for creating a soundscape for a critical interactive, then implementing that cycle for "Ghosts of the Horseshoe."

Developing An Application For Evolutionary Search For Computational Models Of Cellular Development, Nicolas Scott Cornia

Boise State University Theses and Dissertations

VPEvolve is a free and open source application that utilizes a Visual Programming Environment (VPE) for the setup of the Genetic Algorithm (GA), for optimization of computational models. Specifically, the User Interface uses connected glyphs to represent the genetic operators of mutation, reproduction, fitness and selection. These glyphs give the user an intuitive way to set the parameters for the GA, and better visualization of the population's flow through these operators.

VPEvolve is currently being developed alongside research being done in Biocomputing to create models of cellular regeneration based on the regenerative properties of Planaria or flatworms. Since these models …

Secure And Reliable Routing Protocol For Transmission Data In Wireless Sensor Mesh Networks, Nooh Adel Bany Muhammad

Dissertations

Abstract

Sensor nodes collect data from the physical world then exchange it until it reaches the intended destination. This information can be sensitive, such as battlefield surveillance. Therefore, providing secure and continuous data transmissions among sensor nodes in wireless network environments is crucial. Wireless sensor networks (WSN) have limited resources, limited computation capabilities, and the exchange of data through the air and deployment in accessible areas makes the energy, security, and routing major concerns in WSN. In this research we are looking at security issues for the above reasons. WSN is susceptible to malicious activities such as hacking and physical …

Java Animated Software For Teaching The Frank-Wolfe Algorithm For Static Traffic Network Equilibrium, Zhi Li

Computational Modeling & Simulation Engineering Theses & Dissertations

The popular Frank-Wolfe (FW) algorithm for solving the network equilibrium problems plays an important role in transportation simulation. Not only has the basic Frank Wolfe algorithm been studied, but also other variations of the FW algorithm (such as Conjugate Frank Wolfe and Bi-Conjugate Frank Wolfe algorithms) have been extensively studied by the research communities.

In this work, the basic Frank Wolfe algorithm is re-visited for the purpose of developing a useful, user-friendly, and appealing Java computer animation for enhancing the teaching effectiveness of this fundamental transportation static network equilibrium algorithm. Since the shortest path (SP) algorithms (such as the well-known …

Development Of Analytical Sensitivity Analysis For Ahp Applications, Marie L. Ivanco

Mechanical & Aerospace Engineering Theses & Dissertations

Decision makers often face complex problems, which can seldom be addressed without the use of structured analytical models. Mathematical models have been developed over the last 50 years to streamline and facilitate decision making activities. The Analytic Hierarchy Process constitutes one of the most utilized Multi-Criteria Decision Analysis Methods. While AHP has been thoroughly researched and applied, the method still shows limitations in terms of integrating profile disparities of Subject Matter Experts (SMEs). This thesis develops an analytical sensitivity analysis method for AHP based on local partial derivatives to address these limitations. Four examples are presented to demonstrate and validate …

Combination Of A Probabilistic-Based And A Rule-Based Approach For Genealogical Record Linkage, Pooja P. Shah

Master's Theses

Record linkage is the task of identifying records within one or multiple databases that refer to the same entity. Currently, there exist many different approaches for record linkage. Some approaches incorporate the use of heuristic rules, mathematical models, Markov models, or machine learning. This thesis focuses on the application of record linkage to genealogical records within family trees. Today, large collections of genealogical records are stored in databases, which may contain multiple records that refer to a single individual. Resolving duplicate genealogical records can extend our knowledge on who has lived and more complete information can be constructed by combining …

Visualizing Relationships Between Related Variables: Improving Physics Education Through D3.Js Network Visualizations, Stephanie Friend

Liberal Arts and Engineering Studies

phiMap is a web application started by Cal Poly professors and students to aid professors in teaching physics. I developed Javascript visualizations for phiMap that serve to simplify the processes of both teaching and learning physics. These visualizations aim to present relationships between physics variables in an easy to understand manner, and they could eventually have a huge impact on physics education.

Optimizing Harris Corner Detection On Gpgpus Using Cuda, Justin Loundagin

Master's Theses

ABSTRACT

Optimizing Harris Corner Detection on GPGPUs Using CUDA

The objective of this thesis is to optimize the Harris corner detection algorithm implementation on NVIDIA GPGPUs using the CUDA software platform and measure the performance benefit. The Harris corner detection algorithm—developed by C. Harris and M. Stephens—discovers well defined corner points within an image. The corner detection implementation has been proven to be computationally intensive, thus realtime performance is difficult with a sequential software implementation. This thesis decomposes the Harris corner detection algorithm into a set of parallel stages, each of which are implemented and optimized on the CUDA platform. …