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Defined computation

Within the momentum-jump approximation (58), the algorithm provides an in principle exact stochastic realization of the QCL equation. Apart from practical problems to be discussed below, the trajectory implementation therefore represents a well-defined computational scheme. [Pg.294]

Although any well-defined computer data format is potentially usable at this level, languages are particularly suitable for the highest level of communication in federated information systems. [Pg.247]

Fig. 15.24 RADDAR a nearly infinite number of chemical structures can be generated by computationally enumerating combinatorial library proposals. Cherry picking of interesting candidates (proposed structures) based on defined computational algorithms allows the chemist to synthesize the relevant subsets of theoretically accessible molecules. Fig. 15.24 RADDAR a nearly infinite number of chemical structures can be generated by computationally enumerating combinatorial library proposals. Cherry picking of interesting candidates (proposed structures) based on defined computational algorithms allows the chemist to synthesize the relevant subsets of theoretically accessible molecules.
Perhaps the easiest choice to make in defining computer requirements is the hardware. Many people may disagree with this viewpoint. There are dozens of choices of popular hardware platforms, depending on the size of your business or your personal preference. The hardware is, however, not important. The software runs your business. Defining the software that will be needed to do a job is the hard part. Once the software has been chosen, the hardware requirements of the software define the hardware needed. [Pg.429]

Unfortunately the vocabulary of biology is often imprecise. The terms computational biology and bioinformatics are interchangeable in some circles. Here we define computational biology as specifically focusing on the use of... [Pg.1]

A crucial feature of the metal/oxide interface is that it combines the extended nature of the support with the limited size of the supported metal particles - a feature that is common to the study of defects in solids. Such systems pose special problems for realistic modelling. The requirements of defining computationally tractable, as well as accurate models are of particular importance. Three different approaches are common, namely bare clusters, embedded clusters and periodic slab models. All three are associated with approximations, and the best choice must be defined by the correct compromise between cost and accuracy. [Pg.112]

Interim measures are additional controls applied in relation to computer functionality that support critical quality-related activities. They are implemented where compliance gaps are considered to exist, to provide added assurance of control, and to justify the continued use of a computer system. Interim measures are used to supplement or replace defined computer functionality. Examples of interim measures include ... [Pg.348]

The conceptual model of the design process, discussed above (see also Fig. 2), should be turned into a logically well-defined computational process for the computer. There are high-level programming languages, such as FORTRAN, C, LISP, which can bridge the gap between the... [Pg.101]

If we define computational efficiency as the number of steps required to complete the optimization, then random search will be more efficient than explicit gradient calculations when 2T < n. Using the simple approximate estimate T,(n Y) that includes only the first term in the expansion of the exponential, the condition 2T, < n becomes... [Pg.17]

As stated previously, a specifically defined computer program is essential for maintaining inventory control and accountability. There are different software programs available, but beside conventional databases, there are... [Pg.847]

Finally the numerical incompatibility measure for any element in the diagram lattice can be defined. Compute the entropy of the element of interest using equation 3 and identify partitions on the maximum and minimum diversity chains with entropies closest to it. The incompatibility measure is then defined to be the distance between these maximum and minimum diversity partitions, where this distance is defined as the number of boxes (particles) that must be moved to convert the minimum diversity partition to the corresponding maximum diversity partition, and vice-versa. Fig. 4 shows these (normalized) distances for n=500. [Pg.374]

Types of Formal Languages Denotional Semantics - expresses the behaviours of the system using the theory of domains. Operational Semantics - expresses the system as a sequence of actions based on some form of defined computational model. Axiomatic Semantics - expresses the behaviour of the system in terms of preconditions and post conditions which should hold true for each system task. [Pg.308]

As shown in Figure 26.1, the wide gap opens up between the particle and continuum paradigms. This gap cannot be spanned using statistical mechanical methods only. The existing theoretical models to be applied in the mesoscale are based on heuristics obtained via downscaling of macroscopic models and upscaling particle approach. Simphfied theoretical models of complex fluid flows, e.g., flows in porous media, non-Newtonian fluid dynamics, thin film behavior, flows in presence of chemical reactions, and hydrodynamic instabilities formation, involve not only vah-dation but should be supported by more accurate computational models as well. However, until now, there has not been any precisely defined computational model, which operates in the mesoscale, in the range from 10 A to tens of microns. [Pg.719]

When dealing with meta-levels to define computing systems (process expres-sion/actualization) there are at least two layers that always have to be taken into account the process expression/actualization or the meta-model (abstract model) and the specification of the concrete process expression/actualization or the model (concrete model). [Pg.80]

Computer science is the study of all aspects of computers, applied and theoretical. However, considerable disagreement exists over the definition of such basic terms as computer science, computer, hardware, and softvrare. This disagreement can be seen as a testament to the vitality and relative youth of this field. The Association for Computing Machinery s computing classification system, developed in 1998, is an attempt to define computer science. [Pg.424]

The Law Commission defined computer fraud as conduct which involves the manipulation of a computer, by whatever method, in order dishonestly to obtain money, property, or some other advantage of value, or to cause loss. Computer fraud had previously been studied by the Audit Commission in their attempt to assess the extent of crime involving computers. They had sub-divided computer fraud into three categories which they called input frauds, output frauds, and program frauds. [Pg.265]

They given the analysis of the local truncation error and the stability of all the methods mentioned above. For the local error truncation analysis the authors presented the relation between the error and the energy. The authors examined the accuracy and computational efficiency of all the above methods via the numerical approximation of five problems. Conclusions and open problems are also defined. Computational codes written in Maple are presented for the construction of all methods developed in this paper. Subroutines written in Matlab , for the application of the methods described are also presented. [Pg.301]

Note that D, s, and Fg vary with radial and axial positions. For an axial symmetric flow, Fgr = 0 and Fgz = /(r). With the assumption that Z>ax, > and Fg remain unchanged within a defined computational cell and may vary from element to element, the material balance for a species A in a given element, Eq. (33), can be further simplified to... [Pg.342]

Abstract Several potentially useful scalar and vector fields that have been scarcely or even never used to date in Quantum Chemical Topology are defined, computed, and analyzed for a few small molecules. The fields include the Ehrenfest force derived from the second order density matrix, which does not show many of the spurious features encountered when it is computed from the electronic stress tensor, the exchange-correlation (xc) potential, the potential acting on one electron in a molecule, and the additive and effective energy densities. The basic features of the topology of some of these fields are also explored and discussed, paying attention to their possible future interest. [Pg.131]

Simply put, all perpendicular charge flux terms in this case are zero, and the specific element of the APT, 3/r./3Z, is just the atomic charge of atom i. q-,. In this case, therefore, one can equate the empirical atomic charges with well-defined computational observables. ... [Pg.266]

Thus, the in-plane charge flux parameters are the crossed second derivatives of the molecular dipole moment, a well-defined computational observable. [Pg.266]


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See also in sourсe #XX -- [ Pg.808 , Pg.809 ]




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