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Articles 1 - 11 of 11
Full-Text Articles in Engineering
Optimal Pulsed Pumping For Remediation Of Aquifers When Sorption Is Rate-Limited, Lawrence J. Schmitt
Optimal Pulsed Pumping For Remediation Of Aquifers When Sorption Is Rate-Limited, Lawrence J. Schmitt
Theses and Dissertations
A variational optimization technique is developed to acquire an optimal schedule of pulsed pumping operations for use at existing pump-and-treat aquifer remediation sites. The optimization problem is stated as a minimization of a generic management objective functional, constrained by the contaminant transport equations in two-dimensional or three-dimensional flow models which account for rate-limited sorption. The two-dimensional case is fully developed and a first-order rate equation is used to describe the transport of sorbing contaminant. The first variation provides necessary optimality conditions that must be met by any optimal solution, in turn leading to a pulsed pumping schedule of operation. The …
Warning Times And Impact Predictions Of Asteroids And Comets On A Collision Course With Earth, Ahren D. Heidt
Warning Times And Impact Predictions Of Asteroids And Comets On A Collision Course With Earth, Ahren D. Heidt
Theses and Dissertations
This study investigates the amount of data and time necessary to accurately predict Earth impacts of Earth Crossing Objects (ECOs). Trajectories are simulated by numerically integrating in an N-Body system. Given final impact parameters, the trajectory is propagated backwards to an earlier time, creating initial conditions and simulated observation data at requested intervals to which Gaussian random noise is introduced. Utilizing a Bayes Filter to estimate position and velocity from the simulated observation data, the estimate is then propagated forward in time to determine whether or not an impact can be accurately predicted. State vectors and covariance matrices are then …
Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush
Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush
Theses and Dissertations
Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …
Biodegradation Of Deicing Agents In Various Soil Types, Annmarie Halterman-O'Malley
Biodegradation Of Deicing Agents In Various Soil Types, Annmarie Halterman-O'Malley
Theses and Dissertations
Airports have found that spent deicing fluids eventually reach the airfield's stormwater system and soil surrounding the airfield. Due to toxic effects of spent deicing fluids, containing and collecting the fluid for treatment can be a very costly activity for airports. One alternative to dispose of the used deicing fluid is to institute a land treatment system if it can be proven that the deicing fluid is readily biodegradable in a soil system. The primary concern of this research effort was to monitor the behavior of a simulated aircraft deicing fluid in various soil systems. An automated respirometer monitored the …
A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt
A Single Chip Low Power Implementation Of An Asynchronous Fft Algorithm For Space Applications, Bruce W. Hunt
Theses and Dissertations
A fully asynchronous fixed point FFT processor is introduced for low power space applications. The architecture is based on an algorithm developed by Suter and Stevens specifically for a low power implementation. The novelty of this architecture lies in its high localization of components and pipelining with no need to share a global memory. High throughput is attained using large numbers of small, local components working in parallel. A derivation of the algorithm from the discrete Fourier transform is presented followed by a discussion of circuit design parameters specifically, those relevant to space applications. The generic architecture is explained with …
Comparison Of Three Clustering Algorithms And An Application To Color Image Compression, Jihun Cha, Laurene V. Fausett
Comparison Of Three Clustering Algorithms And An Application To Color Image Compression, Jihun Cha, Laurene V. Fausett
Electrical Engineering and Computer Science Faculty Publications
This paper investigates a traditional clustering algorithm (K-means) and two neural networks (SOM and ART-F). The characteristics of each algorithm are illustrated by simulating geometric space data clustering. Then each algorithm is applied to image data sets to compress the size by reducing the number of colors from 256 to 16.
Simulation Model Of Fighter Pilot Assignment Process, Anthony J. Hutfles
Simulation Model Of Fighter Pilot Assignment Process, Anthony J. Hutfles
Theses and Dissertations
This thesis analyzes the effect Continental United States (CONUS) Time on Station (TOS) has on filling critical rated assignments. A SIMSCRIPT II.5 simulation model of the F15 and F16 pilots assignment process was developed. The simulation tested the effect of changing CONUS TOS from 3 years to 6 years in half year increments. Analysis of the number of unfilled rated assignments from simulation runs of 10 years in length indicated that changing CONUS TOS by itself has no statistically significant effect on model's output. The analysis was expanded to a 2(2) factorial experimental design using CONUS TOS and Total Active …
Streamflow Simulation: A Nonparametric Approach, Ashish Sharma, David G. Tarboton, Upmanu L. Lall
Streamflow Simulation: A Nonparametric Approach, Ashish Sharma, David G. Tarboton, Upmanu L. Lall
Civil and Environmental Engineering Faculty Publications
In this paper kernel estimates of the joint and conditional probability density functions are used to generate synthetic streamflow sequences. Streamflow is assumed to be a Markov process with time dependence characterized by a multivariate probability density function. Kernel methods are used to estimate this multivariate density function. Simulation proceeds by sequentially resampling from the conditional density function derived from the kernel estimate of the underlying multivariate probability density function. This is a nonparametric method for the synthesis of streamflow that is data-driven and avoids prior assumptions as to the form of dependence (e.g., linear or nonlinear) and the form …
An Integrated Approach To Simulation And Activity-Based Costing For Evaluating Alternative Manufacturing Cell Designs, Robert Williams, Paul Savory, Rodney Rasmussen
An Integrated Approach To Simulation And Activity-Based Costing For Evaluating Alternative Manufacturing Cell Designs, Robert Williams, Paul Savory, Rodney Rasmussen
Department of Industrial and Management Systems Engineering: Faculty Publications
One effective technique for improving manufacturing efficiency involves the application of group technology part families and manufacturing cells. Selection of the best or optimum configuration of the manufacturing cell relies on the experience and judgment of the cell designer. This paper describes how activity-based costing (ABC) concepts can be integrated into a discrete-event simulation model and be used to evaluate manufacturing cell configurations. The output of the combined ABC simulation model provides a detailed “Bill of Activity” which allows the cell designer to consider costs as a critical factor in the cell design problem. Alternative cell configurations studied in this …
Simulating Queue Scheduling Policies For A Spacecraft Simulator, Paul Savory, Gene Saghi
Simulating Queue Scheduling Policies For A Spacecraft Simulator, Paul Savory, Gene Saghi
Department of Industrial and Management Systems Engineering: Faculty Publications
The mission of the Cassini spacecraft is a unique opportunity to gain insights into major scientific questions about Saturn, the creation of the solar system, and the conditions that led to life on Earth. In preparation for the launch, NASA's Jet Propulsion Laboratory developed a software simulator to emulate the hardware data-control system of the spacecraft. Its primary use is to validate and verify commands that will be transmitted to the spacecraft. To improve the performance of the simulator, we used the SIMAN simulation language to model numerous queue-scheduling policies. Implementation of the simulation results combined with a software-code redesign …
Introduction To Simulation/Optimization Modeling For Groundwater Containment Remediation And (B) Ramifications Of Applying S/O Modeling To Groundwater Containment Remediation, With Case Study Examples, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Normal use of a simulation model to develop a groundwater extraction/injection strategy employs the following process: (1) specify management goals, (2) assume a pumping strategy, (3) simulate system response to the pumping strategy, (4) evaluate acceptability of the system responses, (5) repeat steps (2-4) as required. This is a trial and error approach that is unlikely to actually yield the best pumping strategy for complicated problems