16502051
Parallelization and integration of fire simulations in the Uintah PSE
A physics-based stand-alone serial code for fire simulations is integrated in a unified computational framework to couple with other disciplines and to achieve massively parallel computation. Uintah, the computational framework used, is a component-based visual problem-solving environment developed at the University of Utah. It provides the framework for large-scale parallelization for different applications. The integration of the legacy fire code in Uintah is built on three principles: I) Develop different reusable physics-based components that can be used interchangeably and interact with other components, 2) reuse the legacy stand-alone fire code (written in Fortran) as much as possible, and 3) use components developed by third parties, specifically non-linear and linear solvers designed for solving complex-flow problems. A helium buoyant plume is simulated using the Nirvana machine at Los Alamos National Laboratory. Linear scalability is achieved up to 128 processors. Issues related to scaling beyond 128 processors are also discussed.
41698316
Cloud tracing in convection-diffusion systems
The paper describes a highly interactive method for computer visualization of simultaneous three-dimensional vector and scalar flow fields in convection-diffusion systems. This method allows a computational fluid dynamics user to visualize the basic physical process of dispersion and mixing rather than just the vector and scalar values computed by the simulation. It is based on transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Fluid elements are traced through the vector field for the mean path as well as the statistical dispersion of the fluid elements about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of fluid elements are traced not just mean paths. We have used this method to visualize the simulation of an industrial incinerator to help identify mechanisms for poor mixing.<<ETX>>
117003092
VISUALIZING TURBULENT MIXING OF GASES AND PARTICLES
A physical model and interactive computer graphics techniques have been developed for the visualization of the basic physical process of stochastic dispersion and mixing from steady-state CFD calculations. The mixing of massless particles and inertial particles is visualized by transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Groups of particles are traced through the vector field for the mean path as well as their statistical dispersion about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of particles in a turbulent environment are traced, not just mean paths. In combustion simulations of many industrial processes, good mixing is required to achieve a sufficient degree of combustion efficiency. The ability to visualize this multiphase mixing can not only help identify poor mixing but also explain the mechanism for poor mixing. The information gained from the visualization can be used to improve the overall combustion efficiency in utility boilers or propulsion devices. We have used this technique to visualize steady-state simulations of the combustion performance in several furnace designs.
1517725
Virtual Smoke: an interactive 3D flow visualization technique
A technique is given for computer visualization of simultaneous three-dimensional vector and scalar fields such as velocity and temperature in reacting fluid flow fields. The technique, which is called Virtual Smoke, simulates the use of colored smoke for experimental gaseous fluid flow visualization. However, it is noninvasive and can animate, in particular, the dynamic behaviors of steady-state or instantaneous flow fields obtained from numerical simulations. Virtual Smoke is based on volume seeds and volume seedlings, which are direct volume visualization methods previously developed for highly interactive scalar volume data exploration. Data from combustion simulations are used to demonstrate the effectiveness of Virtual Smoke.<<ETX>>
59784824
A cognitive systems engineering approach to the design of decision support systems
2902641
Teaching problem-solving through a cooperative learning environment
The Biology Sleuth was developed to provide a testbed in which the distribution of critical resources could be varied and the consequent effects on group dynamics and individual learning could be studied. The primary teaching goal of The Biology Sleuth is to teach important problem-solving skills (specifically, diagnostic reasoning) to high school students. In order to meet this goal a cooperative learning [3] environment has been developed in which students work in groups, aided by each other, software, and the classroom teacher,
38064374
A Catalog of Errors
Abstract This paper reviews various errors that have been described by comparing human behavior to the norms of probability, causal connection and logical deduction. For each error we review evidence on whether the error has been demonstrated to occur. For many errors, the occurrence of a bias has not been demonstrated; for other, a bias does occur, but arguments can be made that the bias is not always an error. Based on the conclusions of this review, we caution researchers and practitioners in referring to well known biases and errors.
74708114
The transfusion medicine tutor: the use of expert-systems technology to teach students and provide support to practitioners in antibody identification
The studies presented here provide data regarding the effectiveness of the expert-system-based Transfusion Medicine Tutor (TMT) when used by medical technology students and medical technologists in performing an important problem-solving task, the identification alloantibodies in a patient's blood for the purpose of finding compatible blood for transfusion. TMT monitors for slips and mistakes during the evaluation of patient cases, and provides suggestions to the student or technologist when a potential concern is detected. Use of that system was found to reduce errors in final answers on various multiple antibody cases by 30%-62% by practicing medical technologists. Similarly, use of a modified version of the system for teaching was found to enhance learning by 87--93%.
23806378
Successful Use of an Expert System to Teach Diagnostic Reasoning for Antibody Identification
A previously reported study indicated that, when used by an instructor as a tool to assist with tutoring in a class laboratory setting, use of the Transfusion Medicine Tutor (TMT) resulted in improvements in antibody identification performance of 87-93% (p<.001). Based on input from teachers requesting that TMT be designed for use without the presence of an instructor, a new study on the use of TMT without instructor assistance found that performance improved by 64-66% (p<.001). Finally, based on the results of these two studies, TMT was mailed to 7 sites for beta-testing. In exchange for a free copy of the kit, the instructors (and their students) were asked to fill out questionnaires. Results of these questionnaires are summarized.