Sensitivities of models

Improvements in deterministic (photochemical/diffusion) methods are based largely on accounting for more physicochemical effects in the structure of the model. Specific research subjects for improved models include photochemical aerosol formation and the effects of turbulence on chemical reaction rates. The challenge to the researcher is to incorporate the study of these subjects without needlessly complicating already complex models. How accurate a mathematical simulation is required What, roughly, will be the effect of omitting some particular chemical or physical component What is the sensitivity of model outputs to inaccuracies in the inputs ... 

Further studies examining time-variable behavior of PCBs in the Twelve Mile Creek-Lake Hartwell system and sensitivity of model calculations to various system parameters are presently being performed. The steady-state modeling results presented in this chapter, however, provide a reasonable base for an initial assessment of the fate of PCBs in the Twelve Mile Creek-Lake Hartwell system. The cumulative removals of PCBs from the system by volatilization and burial are shown as percents of the total PCB... 

Sensitization of Model Systems. Silver bromide sheet crystals can be sulfur-sensitized easily, and have been studied extensively (56-58). Evaporated silver halide layers and sprayed emulsions likewise can be sulfur-sensitized. 

Quantitative methods of sensitivity analysis and metrics for measuring sensitivity are widely available. The most commonly used sensitivity analysis methods are often relatively simple techniques that evaluate the local linearized sensitivity of model response at a particular point in the input domain. This type of approach is typically used if the model inputs are treated as point estimates, often representing the best guess as to the true but unknown value of each... 

In the presentation that follows we will consider the mathematical models that have been developed and the model parameters required to predict concentration changes in the animals. In addition, experimental data will be provided that indicate the sensitivity of model parameters to differences in physicochemical form of the elements in the water and to differences in metabolic responses among species. These kinds of... 

Sensitivity of Modeled Ozone Concentrations to Uncertainties in Biogenic Emissions... 

Figure 6.15. Sensitivity of model prediction to yield strength ays [3].

Meyers, T. P. (1987) The sensitivity of modelled S02 fluxes and profiles to stomatal and boundary layer resistance, Water Air Soil Pollut. 35, 261-278. 

The uncertainties and risk criteria in the risk assessment methodology need to be more explicitly studied in the future. The uncertainties usually deals with the sensitivity of modeling parameters to the risk assessment results for different rockfall scenarios. The risk criteria needs to be established to assess the acceptable level of rockfall risk for... 

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