Computer definition

Zhang XH, Chasin LA (2004) Computational definition of sequence motifs governing constitutive exon splicing. Genes Dev 18 1241-1250... 

Combining equations 10,13, and 14 yields the computational definition of the retardation factor ... 

To arrive at a computational definition, the solute velocity can be calculated by dividing the length of the column, L, by the retention time of a given solute. 

This article will deal with these and other aspects of the computer definition in more detail. 

An important ingredient in the analysis has been the positions of zeros of I (x, t) in the complex t plane for a fixed x. Within quantum mechanics the zeros have not been given much attention, but they have been studied in a mathematical context [257] and in some classical wave phenomena ([266] and references cited therein). Their relevance to our study is evident since at its zeros the phase of D(x, t) lacks definition. Euture theoretical work shall focus on a systematic description of the location of zeros. Eurther, practically oriented work will seek out computed or... 

This definition is based on and proportional to the g-expectation value. However, it is more useful since it is not necessary to evaluate the partition function to compute an average. 

A saddle point approximation to the above integral provides the definition for optimal trajectories. The computations of most probable trajectories were discussed at length [1]. We consider the optimization of a discrete version of the action. 

The most well-known and at the same time the earliest computer model for a molecular structure representation is a wire frame model (Figure 2-123a). This model is also known under other names such as line model or Drciding model [199]. It shows the individual bonds and the angles formed between these bonds. The bonds of a molecule are represented by colored vector lines and the color is derived from the atom type definition. This simple method does not display atoms, but atom positions can be derived from the end and branching points of the wire frame model. In addition, the bond orders between two atoms can be expressed by the number of lines. 

The explicit definition of water molecules seems to be the best way to represent the bulk properties of the solvent correctly. If only a thin layer of explicitly defined solvent molecules is used (due to hmited computational resources), difficulties may rise to reproduce the bulk behavior of water, especially near the border with the vacuum. Even with the definition of a full solvent environment the results depend on the model used for this purpose. In the relative simple case of TIP3P and SPC, which are widely and successfully used, the atoms of the water molecule have fixed charges and fixed relative orientation. Even without internal motions and the charge polarization ability, TIP3P reproduces the bulk properties of water quite well. For a further discussion of other available solvent models, readers are referred to Chapter VII, Section 1.3.2 of the Handbook. Unfortunately, the more sophisticated the water models are (to reproduce the physical properties and thermodynamics of this outstanding solvent correctly), the more impractical they are for being used within molecular dynamics simulations. 

Carhart R E, D H Smith and R Venkataraghavan 1985. Atom Pairs as Molecular Features in Structure Activity Studies Definition and Applications. Journal of Chemical Information and Computer Scienc 25 64-73. 

Note that the definite integrals in the members of the elemental stiffness matrix in Equation (2.77) are given, uniformly, between the limits of -1 and +1. This provides an important facility for the evaluation of the members of the elemental matrices in finite element computations by a systematic numerical integration procedure (see Section 1.8). 

To resolve the problems associated with structured and unstructured grids, these fundamentally different approaches may be combined to generate mesh types which partially posses the properties of both categories. This gives rise to block-structured , overset and hybrid mesh types which under certain conditions may lead to more efficient simulations than the either class of purely structured or unstructured grids. Detailed discussions related to the properties of these classes of computational grid.s can be found in specialized textbooks (e.g, see Liseikin, 1999) and only brief definitions are given here. 

The term theoretical chemistry may be defined as the mathematical description of chemistry. The term computational chemistry is generally used when a mathematical method is sufficiently well developed that it can be automated for implementation on a computer. Note that the words exact and perfect do not appear in these definitions. Very few aspects of chemistry can be computed exactly, but almost every aspect of chemistry has been described in a qualitative or approximately quantitative computational scheme. The biggest mistake a computational chemist can make is to assume that any computed number is exact. However, just as not all spectra are perfectly resolved, often a qualitative or approximate computation can give useful insight into chemistry if the researcher understands what it does and does not predict. 

The reaction coordinate is calculated in a number of steps. If too few steps are used, then the points that are computed will follow the reaction coordinate less closely. Usually, the default number of points computed by software packages will give reasonable results. More points may be required for complex mechanisms. This algorithm is sometimes called the IRC algorithm, thus creating confusion over the definition of IRC. 

The following are definitions of terms relevant to computational chemistry. These definitions are based on common usage in this field. They do not necessarily reflect the dictionary definitions or those in other branches of science. 

To gain a proper perspective of the role of computed physical properties, the relationship between estimated and computed properties needs to be understood. A thorough reading of Horvath (25) permits formulation of the following definitions of estimating or computing properties. 

This last definition should be carefully appHed as either an interpolation or an extrapolation, particularly for empirical computational methods based on diverse observations. It is critical that users of molecular modeling tools understand where it is appropriate to apply a technique and where it is not, and what degree of accuracy can be expected. 

The overall failure rate is computed usiag the definition of the rehabiUty, equation 1. 

The CD-I (compact disk-interactive) is a low cost alternative to the CD-ROM for the entertainment industry. CD-I is a subset of the CD-ROM standard data format. It allows the digital storage of data, audio, and video information in a form that permits rapid interaction with a computer. CD-I is compatible to CD-ROM and to CD-AD 0 = 120 mm. The definition of the CD-I format is put down in the Green Book (Philips/Sony). 

Most distillation systems ia commercial columns have Murphree plate efficiencies of 70% or higher. Lower efficiencies are found under system conditions of a high slope of the equiHbrium curve (Fig. lb), of high Hquid viscosity, and of large molecules having characteristically low diffusion coefficients. FiaaHy, most experimental efficiencies have been for biaary systems where by definition the efficiency of one component is equal to that of the other component. For multicomponent systems it is possible for each component to have a different efficiency. Practice has been to use a pseudo-biaary approach involving the two key components. However, a theory for multicomponent efficiency prediction has been developed (66,67) and is amenable to computational analysis. 

Definition / An expert system is a computer program that manipulates large amounts of symboHc knowledge using quaUtative techniques, to solve problems that can otherwise be solved only by expert human problem solvers. Expert systems capture the human problem solver s expertise in the form of domain-specific knowledge and domain-independent problem-solving strategies. 

Definition 2 Knowledge-based systems are computer programs that encode symboHc knowledge about domains and tasks, and solve problems by manipulating this knowledge using quaHtative techniques. 

A multitude of formulas have been developed to accomphsh numerical integration, which consists of computing the value of a definite integral from a set of numerical values of the integrand. 

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