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Articles 1 - 8 of 8
Full-Text Articles in Engineering
The Programmatic Generation Of Discrete-Event Simulation Models From Production Tracking Data, Christopher Rand Smith
The Programmatic Generation Of Discrete-Event Simulation Models From Production Tracking Data, Christopher Rand Smith
Theses and Dissertations
Discrete-event simulation can be a useful tool in analyzing complex system dynamics in various industries. However, it is difficult for entry-level users of discrete-event simulation software to both collect the appropriate data to create a model and to actually generate the base-case simulation model. These difficulties decrease the usefulness of simulation software and limit its application in areas in which it could be potentially useful. This research proposes and evaluates a data collection and analysis methodology that would allow for the programmatic generation of simulation models using production tracking data. It uses data collected from a GPS device that follows …
Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase
Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase
Theses and Dissertations
This thesis presents research on the force and deflection behavior of beams with rectangular cross-sections undergoing lateral torsional buckling. The large 3-D deflection path of buckling beam tips was closely approximated by circular arcs in two planes. A new chain algorithm element was created from pseudo-rigid-body segments and used in a chain calculation that accurately predicted the force deflection relationship of beams with large 3-D deflections.
Optimization Of Shape, Size, And Topology Design Variables In Trusses With A Genetic Algorithm, Kevin M. Gillman
Optimization Of Shape, Size, And Topology Design Variables In Trusses With A Genetic Algorithm, Kevin M. Gillman
Theses and Dissertations
Briggs' genetic algorithm was extended in the Gillman algorithm to include shape optimization of trusses. Other contributions include value representation, different member linking, alternate genes, automatic k-factor evaluation for buckling, and the option to prevent overlapping members. The purpose of these contributions was to make optimization using a genetic algorithm more accessible to design engineers. The Gillman algorithm was demonstrated in two original examples as well as an example from a published work. The Gillman algorithm was effective in finding lighter designs.
Real-Time Adaptive Cancellation Of Satellite Interference In Radio Astronomy, Andrew Joseph Poulsen
Real-Time Adaptive Cancellation Of Satellite Interference In Radio Astronomy, Andrew Joseph Poulsen
Theses and Dissertations
Radio astronomy is the science of observing the heavens at radio frequencies, from a few kHz to approximately 300 GHz. In recent years, radio astronomy has faced a growing interference problem as radio frequency (RF) bandwidth has become an increasingly scarce commodity. A programmable real-time DSP least-mean-square interference canceller was developed and demonstrated as a successful method of excising satellite down-link signals from both an experimental platform at BYU, and the Green Bank Telescope at the National Radio Astronomy Observatory in West Virginia. A performance analysis of this cancellation system in the radio astronomy radio frequency interference (RFI) mitigation regime …
Channel Probing For An Indoor Wireless Communications Channel, Brandon Hunter
Channel Probing For An Indoor Wireless Communications Channel, Brandon Hunter
Theses and Dissertations
The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter …
Boundary Control For Automated Sweeping Of Finite Element Meshes, Robert A. Kerr
Boundary Control For Automated Sweeping Of Finite Element Meshes, Robert A. Kerr
Theses and Dissertations
Finite element analysis depends greatly upon a high-quality mesh to be able to provide reasonably accurate answers to engineering problems. Models that need to be analyzed using finite element analysis are becoming increasingly more complex, and correspondingly harder to mesh with good quality. Skew is one quality metric which can cause problems with finite element analyses. This thesis explains how skew is calculated, discusses two common sources of skew: multiply-linked surfaces with interval constraints, and biased edge meshes. Two methods of lessening skew in surface meshes are then presented: the skew control algorithm, and the curve morphing algorithm. These algorithms …
A Practical Algorithm For Designing H∞ Control Laws, Timothy Mclain, Randal W. Beard
A Practical Algorithm For Designing H∞ Control Laws, Timothy Mclain, Randal W. Beard
Faculty Publications
We describe an approximation method for the Hamilton-Jacobi-Isaacs (HJI) equation that results in feedback control. The approximation is accomplished via a two-step successive Galerkin approximation scheme. An application of the technique to the control of the forward motion of an underwater vehicle is described.
A General Three Dimensional All Quadrilateral Surface Mesh Generation Algorithm, Roger Cass
A General Three Dimensional All Quadrilateral Surface Mesh Generation Algorithm, Roger Cass
Theses and Dissertations
Among the available all-quadrilateral mesh generation algorithms progressive-front offers the best quality and robustness. The paving algorithm is a progressive-front technique that generates a two dimensional mesh of all quadrilaterals on planar surfaces. The technique is particularly suited to meshing irregular boundaries with interior holes. This thesis presents an extension of the paving algorithm to generalized three dimensional surfaces. The major problems in three-dimensional surface mesh generation are projection of nodes, calculation of interior angles, and connection of mesh fronts. The solutions to these problems are presented. This work is part of the ongoing CUBIT project at Sandia Labs. The …