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Hybrid modelling responses

Employing the additivity approximation, we find dielectric response of a reorienting single dipole (of a water molecule) in an intermolecular potential well. The corresponding complex permittivity jip is found in terms of the hybrid model described in Section IV. The ionic complex permittivity A on is calculated for the above-mentioned types of one-dimensional and spatial motions of the charged particles. The effect of ions is found for low concentrated NaCl and KC1 aqueous solutions in terms of the resulting complex permittivity e p + Ae on. The calculations are made for long (Tjon x) and rather short (xion = x) ionic lifetimes. [Pg.81]

The main advantage of the hat-curved potential is that it is possible to narrow the width Avor of the librational absorption band by decreasing the form factor /. Indeed, Avor attains its maximum value when/ = 1. Note that / = 1 is just the case of the hat flat or its simplified variant, the hybrid model, both of which were described in Section IV. The latter was often applied before (VIG) and is characterized by a rather wide absorption band, especially in the case of heavy water. In another extreme case, / — 0, the linewidth Avor becomes very low. When / = 0, we have the case of the parabolic potential well, whose dielectric response was described, for example, in GT and VIG. Thus, when the form factor/of the hat-curved well decreases from 1 to 0, the width Avor decreases from its maximum to some minimum value. [Pg.229]

Hypotheses for the formation of odids There are three primary classes of hypotheses for the processes responsible for the existence of odids. They are based on bacterial-mechanical, algal, or chemical mechanisms for odid formation. Some investigators have made hybrid models involving more than one of these mechanisms. Because the previously cited papers cover the literature up to about 1980, we will only present these hypotheses in a general manner and not attempt to reference the large number of papers relevant to the topic. [Pg.232]

Regarding handling of model responses, process inversion (calculation of u°p with the help of the model) can be performed implicitly with the help of numerical procedures (the model provides process responses y as functions of inputs u and initial states x), or can be performed explicitly, by developing empirical and/or hybrid neural models off-line (the model provides inputs u as functions of process responses y and initial states x) [ 196, 203-206]. In the first case, model responses are more robust, although model inversion is much faster in the second case. Besides, if the process model can be fairly described by linear or bilinear models, then analytical results can be provided for the optimization problem [40,193,207,208], which makes the real-time implementation of predictive controllers much easier. [Pg.355]

The software implemented is capable of learning, hence it will improve its performance with time. A user interface adapted to the process engineer responsible for the production allows to improve and extend the rule system of the heuristic component. The extent of the basic mathematical model clearly depends on the knowledge available about the process under consideration. It should be extended by relationships between the different quantities, e.g., the yield expressions within the balances based on stoichiometric or thermodynamic considerations whenever more detailed knowledge becomes available. Thus, it is strongly suggested to reexamine hybrid models from time to time with the aim of improving the classical mechanistic part of the model. [Pg.154]

As ARRs derived from a hybrid model are mode dependent, it is important for an online FDI to know the current mode in order to use the correct values of the discrete states in the ARRs so that ARR residuals can serve as indicators of fault in the current system mode. It turns out that an evaluation of all ARRs or a subset of ARRs in case the previous mode is known can be used to identify the current system mode. The task can be performed in parallel in order to minimise the response time. [Pg.237]

The enhanced viscoelastic functions are attributable to additional relaxation processes that occur at low frequencies associated with deformation of the dispersed phase. Therefore, for cases such as mPE/LDPE, where partial miscibility at high LDPE content and the extremely different relaxatimi times of the phases in the blends rich in mPE are observed, a hybrid model including the double reptation approach for the matrix and the linear Palieme approach for the whole system could successfully explain the viscoelastic response of these blends (Peon et al. 2003). [Pg.784]

Prodan, E. Radloff, C. Halas, N. J. Nordlander, P. A hybridization model for the plasmon response of complex nanostructures. Science 2003, 302, 419-422. [Pg.328]

Fig. 30.13. Hybrid model step responses for q for changes in the input Xf (a) and Tjacket (b)- Solid line... Fig. 30.13. Hybrid model step responses for q for changes in the input Xf (a) and Tjacket (b)- Solid line...
Fig. 30.18. Hybrid model step response for changes in r(a) and /(b) for a positive and negative load change in Qheating- Solid line hybrid model, dots measurements. Fig. 30.18. Hybrid model step response for changes in r(a) and /(b) for a positive and negative load change in Qheating- Solid line hybrid model, dots measurements.
LSTC, Livennore, California, USA), which was then used to simulate the notched specimen tests. Vahdation of the Hybrid Model was performed by direct comparison of the effective stress-strain response from the FEA and the notched experimental tests and by calculating the coefficient of determination, R. ... [Pg.481]

UHMWPE specimens subjected to very small strains, while exploration of hyperelasticity theory led to the conclusion that it is often safer to use a more sophisticated constitutive model when modeling UHMWPE. The use of linear viscoelasticity theory led to a reasonable prediction for the response of the material during a uniaxial compression test however, even small changes to the strain rate rendered the previously identified material parameters unsatisfactory. Isotropic J2-plasticity theory provided excellent predictions under monotonic, uniaxial, constant-strain rate, constant-temperature conditions, but it was unable to predict reasonable results for a cyclic test. The augmented Hybrid Model was capable of predicting the behavior of UHMWPE during a uniaxial tension test, a cyclic uniaxial fully... [Pg.530]


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