Browsing by Subject "Mathematical models"

Now showing 1 - 3 of 3
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    Access to Destinations: Monitoring Land Use Activity Changes in the Twin Cities Metropolitan Region
    (Minnesota Department of Transportation, 2008-07) Iacono, Michael; Levinson, David; El-Geneidy, Ahmed; Wasfi, Rania; Zhu, Shanjiang
    This study presents an effort to track and model land use change in the Twin Cities Metropolitan Region. To that end, we make use of a unique, high-resolution, cell-level set of land use data for the Twin Cities. The data represent 75 meter by 75 meter land use cells, observed at several points in time during the period from 1958 to 2005. These data are used to validate three different types of land use models, which then are used to forecast land use several decades into the future. The models applied in this study include Markov Chain models, Markov Chain-Cellular Automata (MC-CA) models, and an empirical model based on a logistic regression specification. The models are intended to have a simple, transparent structure that allows the user to identify sources of forecast error. Forecasts of land use are made both for the entire study area and also for a specific corridor along State Highway 610 in the northwestern suburbs of the Twin Cities. The study concludes with a brief discussion of the limitations of the models, and how they might meaningfully be expanded and applied.
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    Development of a CFD Primary Cooling Fan Model for Prediction of Air Flow in the Primary Cooling Zone of Line 2 at United Taconite
    (University of Minnesota Duluth, 2008) Englund, David J
    A CFD model of the Line 2 Primary Cooling Fan (3A) has been developed and demonstrated to be capable of reproducing the fan curve as supplied with the fan. The effect of air temperature and inlet damper position have been simulated and used to produce a series of flow-pressure curves for the unit as it operates in the plant. The plant fan model appears capable of reproducing the air survey velocity pressure profiles measured on July 11, 2006. The United Taconite CFD Cooler Model was then used to develop a family of system resistance curves based on cooler operating parameters. The fan and system resistance curves, when combined, allow the fan operating point to be defined, from which flow can be predicted. Several linear models were developed and then used to predict plant performance, using the July 11, 2006, operating point. The predictions fall within 8% on a volume flow basis, within 6% on a mass basis. Additional operating points are needed to demonstrate the model's predictive capability over a flow range. Based on the results in this report, it appears possible that an on-line flow prediction model could be developed with additional research.
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    Development of a Mathematical Model of the High Pressure Rolls for Magnetic Taconite Comminution
    (University of Minnesota Duluth, 2006-04) Benner, Blair R