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Causal constraint

There is a constraint between the causality of two or more ports of a node. This is the case for the elementary two port nodes (M)TF and (M)GY the (M)TF always has only one stroke at the node, while the (M)GY has either both strokes at the node or both open ends. The junctions also have such a causal constraint an -port 0-junction has one stroke at the node and n - 1 open ends, while an -port 1-junction has one open end at the node and n - 1 causal strokes. The same holds for the XO and the XI in principle, but in many cases they will be given a fixed causality, given the discontinuous and consequently non-invertible nature of their constitutive relations. [Pg.23]

ARRs generation consists in eliminating unknown variables d and / by following the causal path from a known variable to an unknown one. However, the elimination of the unknown variable on the considered causal constraint is not always possible. In the algebraic case where the equation is nonlinear, calculating the variable can be done only in one way. [Pg.117]

For each element of which causality is imposed (sources, elements with non-invertible constitutive laws) assign it and propagate it through the junction structure taking into account the causality constraints ofO- and I-junctions, TF- and GY-elements. [Pg.207]

Along each power line chosen at step I propagate bicausality from the double source to the double detector and propagate causality through the junction structure taking into account the causality constraints ofO- and I-junctions, TF-and GY-elements. If at this step causal conflicts or non-solvable causal loops appear, repeat the previous steps with another set of disjoint I/O power lines. If none of them solves the problem of causal conflicts or non-solvable causal loop appearance then the model is not invertible (Criterion 3) and the procedure stops. [Pg.207]

For the initial ineffective observation element, information about the transformation was not available on the tactical level. Moreover, no information was available of previous deviations. Finally, constraints for orders to be delivered in time were present, as fines were levied for each day of late delivery (information regarding the organizational values and norms). The types of causal latent conditions are information regarding, transformation, history and organizational values and norms. These three types of latent conditions cause the ineffectiveness of the observation element and enabled the re-occurrences of substances in the packaging machines when performing maintenance. [Pg.102]

The general principles of indicators of exposures or effects have not been widely discussed in the literature. Some information is found in WHO, (2001). From the examples mentioned above it appears that indicator or substitute measures are used when exact measurements of effects or exposures are difficult to use for economical, time, or practical constraints. The indicator variable or substitute measure can be any variable with a known (causal or non-causal) association to the variable in question. It should be noted that when causality is established this exposure measure becomes an indicator of the effect and vice versa. In many cases only an association exists and often only within a limited range of exposure situations. [Pg.333]

The CPA method has important properties apart from its relative simplicity. It is analytic in z,158 and thus respects the elementary physical constraints causality, Kramers-Kronig relations, sum rules, positive definite spectrum, etc. What is more, it is universal this method describes the virtual-crystal limit A W, the isolated-impurity limit cA - 0 or cA - 1, and the isolated-molecule limit W- 0, with the correct contribution of each molecular level.122 Indeed, the CPA may be derived159 from this last limit, as well as from that in the locator formalism.122... [Pg.203]

In the specific area of development of viscoelastic polymers for sound attenuation and vibration damping, the need is to identify materials with high intrinsic absorption which are also relatively temperature and pressure independent. These conditions can be optimized within the constraints of the general causal relations between the real and imaginary parts of the moduli. [Pg.204]

The fimdamental constraints are that the system be stable, in the sense that perturbations to the system do not grow, that the system responds linearly to a perturbation, and that the system be causal in the sense that a response to a perturbation cannot precede the perturbation. The Kramers-Kronig relationships were foimd to be entirely general with application to all frequency-domain measiuements that could satisfy the above constraints. Bode extended the concept to electrical impedance and tabulated various extremely useful forms of the Kramers-Kronig relations. ... [Pg.427]

The Kramers-Kronig relations are extremely general emd have been applied to a wide variety of research areas. In the field of optics, for which the validity of the Kramers-Kronig is not in question, the relationship between real and imaginary components has been exploited to complete optical spectra. In other areas where data cannot be assumed to satisfy the requirements of the Kramers-Kronig relations, the equations presented in Table 22.1 have been used to check whether real and imaginary components of complex variables are internally consistent. Failure of the Kramers-Kronig relations is assumed to correspond to a failure within the experiment to satisfy one or more of the constraints of linearity, stability, or causality. [Pg.438]

Vigorous controversies notwithstanding, I must begin by acknowledging that the roles of constraint and contingency in evolutionary processes are, of course, not mutually exclusive. In fact they are mutually necessary (Carroll, 2001). Nevertheless, a significant amount of both the scientific and interdisciplinary literature on these issues has been characterized by an unnecessary dichotomization of causal explanations and a regrettable polarization of rhetoric. There are two reasons for this, both of which I hope at least to avoid, if not to redress. [Pg.320]

The constructive model P(A(M) SC C )xN) acts as before, as a filter on the prior P(S( -C)x I A) output from the cosmological theory. In this respect, the anthropic bias is indistinguishable from the pruning rule generated by Hoyle but as it is driven by incomplete theoretical specification rather than mere intractability, the posterior distribution is not provisional and cannot act as a constraint on reductionist refinements of N or X It is not a substitute for a theory of particular initial conditions, because it adds nothing axiomatic to the structure of the causal theories represented by... [Pg.414]


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