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Deterministic systems

This approach needs modification as soon as multiple attracting periodic trajectories exist for a particular set of operating parameters. A conceptually different modification will be necessary to account for attractors which are not simply periodic. Quasi-periodic solutions, characterized by multiple frequencies, are the first type one should expect these are by no means exotic but occur generally in several periodically forced systems. Deterministic chaotic situations, arising from the system nonlinearities (and not the stochastic responses due to random noise) need not be discarded as intractable (Wolf et al., 1986 Shaw, 1981). [Pg.228]

Deterministic responses from exposure to hazardous chemicals generally are of concern in health protection of the public because many of the exposure limits derived from the assumed thresholds and the applied safety and uncertainty factors fall within the range of potential routine exposures. However, the possibility that the large safety and uncertainty factors normally used in setting exposure limits are quite conservative (pessimistic) could be taken into account in developing a risk-based waste classification system. Deterministic responses from exposure to radionuclides should not be of concern in health protection of the public or in classifying waste, because the dose limits intended to prevent deterministic responses are substantially higher than the dose limit intended to limit the occurrence of stochastic responses. [Pg.162]

Protection system Deterministic control of functions and performance, including abihty to neutralize, heal, or shed threats Embedded sensors... [Pg.42]

For motion in a diss tive deterministic chaotic system, deterministic chaotic diffiision along a coordinate x is developed according to the following condition (5P) ... [Pg.192]

Frankowicz, M. (1984). Relaxation processes in spatially distributed bistable chemical systems deterministic and stochastic analysis. In Non-equilibrium dynamics in chemical systems, eds C. Vidal A. Pacault (Springer Series in Synergetics, Vol. 27), p. 232. Springer Verlag, Berlin. [Pg.229]

For difficult corrosion problems, models built from the bottom up are realistic—models tied to experimental empirical data and observations of a particular system. Deterministic models are derived in a top-down manner from abstract laws and are typically less realistic but more general. Accordingly, there are two complementary approaches for developing corrosion models and predicting corrosion damage ... [Pg.172]

It is also able to draw complex mathematical figures, including many fractals. Dynamics Solver is a powerful tool for studying differential equations, (eontinuous and diserete) nonlinear dynamieal systems, deterministic chaos, mechanics, and so forth. For instance, you can draw phase space portraits (including an optional direction field). Poincare maps, Liapunov exponents, histograms, bifurcation diagrams, attraction basis, and so forth. The results can be watehed (in perspective or not) from any direction and particular subspaces ean be analyzed. [Pg.650]

Relaxation Processes in Spatially Distributed Bistable Chemical Systems Deterministic and Stochastic Analysis... [Pg.232]

This is a question of reaction prediction. In fact, this is a deterministic system. If we knew the rules of chemistry completely, and understood chemical reactivity fully, we should be able to answer this question and to predict the outcome of a reaction. Thus, we might use quantum mechanical calculations for exploring the structure and energetics of various transition states in order to find out which reaction pathway is followed. This requires calculations of quite a high degree of sophistication. In addition, modeling the influence of solvents on... [Pg.542]

Another popular approach to the isothennal (canonical) MD method was shown by Nose [25]. This method for treating the dynamics of a system in contact with a thennal reservoir is to include a degree of freedom that represents that reservoir, so that one can perform deterministic MD at constant temperature by refonnulating the Lagrangian equations of motion for this extended system. We can describe the Nose approach as an illustration of an extended Lagrangian method. Energy is allowed to flow dynamically from the reservoir to the system and back the reservoir has a certain thermal inertia associated with it. However, it is now more common to use the Nose scheme in the implementation of Hoover [26]. [Pg.59]

An algorithm for performing a constant-pressure molecular dynamics simulation that resolves some unphysical observations in the extended system (Andersen s) method and Berendsen s methods was developed by Feller et al. [29]. This approach replaces the deterministic equations of motion with the piston degree of freedom added to the Langevin equations of motion. This eliminates the unphysical fluctuation of the volume associated with the piston mass. In addition, Klein and coworkers [30] present an advanced constant-pressure method to overcome an unphysical dependence of the choice of lattice in generated trajectories. [Pg.61]

D. M. Himmelblau and K. B. Bischoff, Process Analysis Simulation-Deterministic Systems, John Wiley, 1968. [Pg.300]

System models assume the independent probabilities of basic event failures. Violators oithis assumed independence are called Systems Interactions, Dependencies, Common Modes, or Common Cause Failure (CCF) which is used here. CCF may cause deterministic, possibly delayed, failures of equipment, an increase in the random failure probability of affected equipment. The CCF may immediately affect redundant equipment with devastating effect because no lime is available for mitigation. If the effect of CCF is a delayed increase in the random failure probability and known, time is available for mitigation. [Pg.123]

CCF means different things to different people. Smith and Watson (1980) define CCF as the inability of multiple components to perform when needed to cause the loss of one or moi e systems. Virolainen (1984) criticizes some CCF analyses for including design errors and poor quality as CCF and points out that the phenomenological methods do not address physical and statistical dependencies. Here, CCF is classed as known deterministic coupling (KDC), known stochastic coupling (KSC), and unknown stochastic coupling (USC). [Pg.124]

The analyses of system failures which could challenge the containment or lead to the release of radioactivity form the licensing process. The design basis analyses are deterministic, and degraded core accidents are not considered. PSA determines the probabilities of the numerous sequences that could lead to core degradation and how the core behaves. [Pg.309]

Representativeness can be examined from two aspects statistical and deterministic. Any statistical test of representativeness is lacking becau.se many histories are needed for statistical significance. In the absence of this, PSAs use statistical methods to synthesize data to represent the equipment, operation, and maintenance. How well this represents the plant being modeled is not known. Deterministic representativeness can be answered by full-scale tests on like equipment. Such is the responsibility of the NSSS vendor, but for economic reasons, recourse to simplillcd and scaled models is often necessary. System success criteria for a PSA may be taken from the FSAR which may have a conservative bias for licensing. Realism is more expensive than conservatism. [Pg.379]

The PSA (Miller, 1990, Wyss, 1990a, 1990b) consisted of three steps 1) issues important to safety were identified by "brainstorms" constructed as an accident progression event tree, 2) deterministic calculations were performed on the issues when information was not available from previous calculations or similar systems, and 3) information from step 2 was used to elicii e.vpert Judgement of the issues identified in step 1. [Pg.423]

Particle trajectories can be calculated by utilizing the modern CFD (computational fluid dynamics) methods. In these calculations, the flow field is determined with numerical means, and particle motion is modeled by combining a deterministic component with a stochastic component caused by the air turbulence. This technique is probably an effective means for solving particle collection in complicated cleaning systems. Computers and computational techniques are being developed at a fast pace, and one can expect that practical computer programs for solving particle collection in electrostatic precipitators will become available in the future. [Pg.1228]

By far the most common methods of studying aqueous interfaces by simulations are the Metropolis Monte Carlo (MC) technique and the classical molecular dynamics (MD) techniques. They will not be described here in detail, because several excellent textbooks and proceedings volumes (e.g., [2-8]) on the subject are available. In brief, the stochastic MC technique generates microscopic configurations of the system in the canonical (NYT) ensemble the deterministic MD method solves Newton s equations of motion and generates a time-correlated sequence of configurations in the microcanonical (NVE) ensemble. Structural and thermodynamic properties are accessible by both methods the MD method provides additional information about the microscopic dynamics of the system. [Pg.349]

This formulation is not just a mathematical trick to form an antisymmetric vravefunction. Quantum mechanics specifies that an electron s location is not deterministic but rather consists of a probability density in this sense, it can he anywhere. This determinant mixes all of the possible orbitals of all of the electrons in the molecular system to form the wavefunction. [Pg.260]

It should be realized that unlike the study of equilibrium thermodynamics for which a model is often mapped onto Ising system, elementary mechanism of atomic motion plays a deterministic role in the kinetic study. In an actual alloy system, diffusion of an atomic species is mainly driven by vacancy mechanism. The incorporation of the vacancy mechanism into PPM formalism, however, is not readily achieved, since the abundant freedom of microscopic path of atomic movement demands intractable number of variational parameters. The present study is, therefore, limited to a simple spin kinetics, known as Glauber dynamics [14] for which flipping events at fixed lattice points drive the phase transition. Hence, the present study for a spin system is regarded as a precursor to an alloy kinetics. The limitation of the model is critically examined and pointed out in the subsequent sections. [Pg.84]

Probabilistic CA. Probabilistic CA are cellular automata in which the deterministic state-transitions are replaced with specifications of the probabilities of the cell-value assignments. Since such systems have much in common with certain statistical mechanical models, analysis tools from physics are often borrowed for their study. Probabilistic CA are introduced in chapter 8. [Pg.18]

Despite bearing no direct relation to any physical dynamical system, the onedimensional discrete-time piecewise linear Bernoulli Shift map nonetheless displays many of the key mechanisms leading to deterministic chaos. The map is defined by (see figure 4.2) ... [Pg.172]

Deterministic Randomness. On the one hand, equation 4.8 is a trivial linear difference equation possessing an equally as trivial solution for each initial point Xq Xn = 2"a o (mod 1). Once an initial point is chosen, the future iterates are determined uniquely. As such, this simple system is an intrinsically deterministic one. On the other hand, look again at the binary decimal expansion of a randomly selected a o- This expansion can also be thought of as a particular semi-infinite sequence of coin tosses. [Pg.175]

As before, we set po = 0 to have o = 0 as the single absorbing state.Table 7.2 shows the eight deterministic-rule corners of the (pi,p2,p3)-cube. Figure 7.7 shows three slices of the phase-diagram of this system. We see that there always exists... [Pg.348]

Let us first of all consider the deterministic Life rule, or zero temperature limit of our more general stochastic rule. Using the density p to represent our state of knowledge of the system at time t, our problem is then to estimate the time-evolution of p for T = 0. [Pg.364]

The form of the stochastic transfer function p x) is shown in figure 10.7. Notice that the steepness of the function near a - 0 depends entirely on T. Notice also that this form approaches that of a simple threshold function as T —> 0, so that the deterministic Hopfield net may be recovered by taking the zero temperature limit of the stochastic system. While there are a variety of different forms for p x) satisfying this desired limiting property, any of which could also have been chosen, this sigmoid function is convenient because it allows us to analyze the system with tools borrowed from statistical mechanics. [Pg.529]

Consider the simplest type of L-system namely, a deterministic context-free L-system, also called a DOL-Systeni. As the name implies, the production rules of such systems are allowed to transform only single symbols i.e. the dynamics is independent of all neighboring symbol values. DOL-Systems are thus generalized CA systems that are allowed to add sites but whose local rule depends only on a given site itself and none of its neighbors. [Pg.576]


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See also in sourсe #XX -- [ Pg.41 , Pg.43 , Pg.50 , Pg.242 , Pg.275 , Pg.277 , Pg.281 ]




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