Normal distribution Terms Links

Another aspect of matching output to user needs involves presentation of results in a statistical framework—namely, as frequency distributions of concentrations. The output of deterministic models is not directly suited to this task, because it provides a single sample point for each run. Analytic linkages can be made between observed frequency distributions and computed model results. The model output for a particular set of meteorologic conditions can be on the frequency distribution of each station for which observations are available in sufficient sample size. If the model is validated for several different points on the frequency distribution based on today s estimated emission, it can be used to fit a distribution for cases of forecast emission. The fit can be made by relating characteristics of the distribution with a specific set of model predictions. For example, the distribution could be assumed to be log-normal, with a mean and standard deviation each determined by its own function of output concentrations computed for a standardized set of meteorologic conditions. This, in turn, can be linked to some effect on people or property that is defined in terms of the predicted concentration statistics. The diagram below illustrates this process ... 

The dual site-bond description (DD) of disordered stmctures [3] allows a proper modeling of the porous structure. In the context of this treatment, two kinds of alternately intercormected void entities are thought to conform the porous network, i.e. the sites (cavities) and the bonds (capillaries, necks). C bonds meet into a site and each bond is the link between two sites. Thus a twofold distribution of sites and bonds is required to construct a porous network. For simplicity, the size of each entity can be measured in terms of a quantity, R, defined as follows for sites, considered as hollow spheres, R is the radius of the sphere while for bonds, idealized as hollow cylinders open at both ends, R is the radius of the cylinder. Under the DD scheme, FgfR) andFg(R)are the size distribution density functions, for sites and bonds respectively, on a number of elements basis and normalized so that the probabilities to find a site or a bond having a size R or smaller are ... 

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