Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

A deterministic model

As a preliminary step, we investigate the result of using a deterministic model, the expected value problem (EV). For the first-stage solution obtained from EV, the objective of the 2S-MILP is EEV = —12.00. [Pg.209]

The convective model is a deterministic model thus, the spread of tracer grows linearly with distance, or... [Pg.341]

Determination of optimal conditions in the lab, pilot and full-scale plants is among the most complex problems for a researcher and it belongs to the group of extreme problems. This complexity is caused by the nature of technological processes, which simultaneously include chemical reaction, transfer of mass, heat transfer and momentum transfer. It does not allow to form, by well-known theoretical knowledge, a deterministic model for establishing an optimum analytically. [Pg.385]

In the present study, the problem is written as a nonlinear programming problem and is solved with SQP technique. Two process models are evaluated when the process is optimized using the SQP technique. The first one is a deterministic model with the kinetic parameters determined by Atala et al. (1), and the second one is a statistical model obtained using the factorial design technique combined with simulation. [Pg.487]

Through the following procedure the equations for a deterministic model can be obtained ... [Pg.185]

Since this monograph is devoted only to the conception of mathematical models, the inverse problem of estimation is not fully detailed. Nevertheless, estimating parameters of the models is crucial for verification and applications. Any parameter in a deterministic model can be sensibly estimated from time-series data only by embedding the model in a statistical framework. It is usually performed by assuming that instead of exact measurements on concentration, we have these values blurred by observation errors that are independent and normally distributed. The parameters in the deterministic formulation are estimated by nonlinear least-squares or maximum likelihood methods. [Pg.372]

In this example, we can use a deterministic model based on the particularization of the unsteady state heat balance and transfer equations. The particularization can be carried out considering either the whole exchanger or a part of it. The model that can present different degrees of complication is determined by the heat exchanger construction and by the models of flow used for the hot and cold fluids. [Pg.312]

The statistical modelling of a process can be applied in three different situations (i) the information about the investigated process is not complete and it is then not possible to produce a deterministic model (model based on transfer equations) (ii) the investigated process shows multiple and complex states and consequently the derived deterministic or stochastic model will be very complex (iii) the researcher s ability to develop a deterministic or stochastic model is limited. [Pg.325]

Fig. 16.1 (a) Deterministic modelling systems developed at DMI and (b) model nesting in Urban Air Quality Information and Forecasting Systems (UAQIFS) (... common regulatory models FUMAPEX multi-scale systems new suggested down-scaling with obstacle-resolved models)... [Pg.168]

Fennel, K., Spitz, Y. H., Leteker, R.M., Abbott, M. R., and Karl, D.M. (2002). A deterministic model for N2-fixation at station ALOHA in the subtropical North Pacific Ocean. Deep Sea Rjes. 1149, 149—174. [Pg.763]

The typical outcome of quasi-species behavior is natural selection in the Darwinian sense. We believe that it should be possible to adapt the quasispecies model to any situation where natural selection in the Darwinian sense plays a major role. Hence the model may be generalized so as to include all kinds of horizontal gene transfer typical for recombination. The model as presented is essentially a deterministic model that holds only for a sufficiently large population size. This limitation and a possible way to overcome it will be the subject of the final section. [Pg.242]

MD allows the study of the time evolution of an V-body system of interacting particles. The approach is based on a deterministic model of nature, and the behavior of a system can be computed if we know the initial conditions and the forces of interaction. For a detail description see Refs. [14,15]. One first constructs a model for the interaction of the particles in the system, then computes the trajectories of those particles and finally analyzes those trajectories to obtain observable quantities. A very simple method to implement, in principle, its foundations reside on a number of branches of physics classical nonlinear dynamics, statistical mechanics, sampling theory, conservation principles, and solid state physics. [Pg.81]

Models are also classified into whether they are deterministic or stochastic. Stochastic (Greek for guess ) systems involve chance or probability, whereas a deterministic system does not. In a deterministic model no randomness is assumed to be present, an assumption that is clearly not realistic. Stochastic models assume random variability and take into account that variability. There is no such thing as a deterministic model—all... [Pg.6]

A strange attractor resulting from such a deterministic model is called deterministic chaos to emphasize the fact that it is not a random or stochastic variation. [Pg.80]

Expressions for Growth Rate. At this stage, a model must be introduced if further progress is to be made, and we choose a deterministic model. All deterministic models which have been introduced (with two exceptions) have been autonomous they assume that the growth rates are explicit functions only of the state of the system, and not of time. But state in an unstructured model can only refer to population density or to concentration of protoplasm, since, by definition, a model is unstructured if only one state variable appears. Thus, the model is... [Pg.133]

Differences such as these are even more pronounced with regard to maintenance. Few facilities have equal levels of maintenance support around the clock—typically it will take longer to find maintenance help at nights, and on the weekends. There is no way that a deterministic model can incorporate complexities and variations of this type. [Pg.644]

In all of the above methods we need a model of the process as the core of our computational problem. A model is a set of equations connecting all process parameters and a set of constraints in the form of inequalities describing adequately the behavior of the system. When all process parameters are determined with a probability equal to 1 we have a deterministic model, otherwise the model is a stochastic one. [Pg.52]

The following five parts of a deterministic model can usually be distinguished ... [Pg.53]

The NFPA 130 utilises a deterministic model evaluating the evacuation time through a series of egress elements (walkways, escalators, turnstiles...) on the passengers route to safety. [Pg.958]


See other pages where A deterministic model is mentioned: [Pg.267]    [Pg.204]    [Pg.604]    [Pg.59]    [Pg.111]    [Pg.294]    [Pg.53]    [Pg.292]    [Pg.533]    [Pg.485]    [Pg.104]    [Pg.43]    [Pg.224]    [Pg.61]    [Pg.206]    [Pg.189]    [Pg.1490]    [Pg.473]    [Pg.506]    [Pg.12]    [Pg.309]    [Pg.751]    [Pg.360]    [Pg.295]    [Pg.62]    [Pg.26]    [Pg.103]    [Pg.483]    [Pg.254]    [Pg.955]    [Pg.36]   


SEARCH



Deterministic

Deterministic models

Model deterministic models

© 2024 chempedia.info