Simple orthogonalization

Note that Eq. (9.1) applies to pore arrays as well as to randomly distributed pores. For simple orthogonal or hexagonal arrays of macropores with one pore per unit cell of the pattern, the porosity can be defined locally as the ratio between the cross-sectional area of the pore AP and the area of the unit cell AU as shown in Fig. 9.15 a ... 

Two major forms of the OCFE procedure are common and differ only in the trial functions used. One uses the Lagrangian functions and adds conditions to make the first derivatives continuous across the element boundaries, and the other uses Hermite polynomials, which automatically have continuous first derivatives between elements. Difficulties in the numerical integration of the resulting system of equations occur with the use of both types of trial functions, and personal preference must then dictate which is to be used. The final equations that need to be integrated after application of the OCFE method in the axial dimension to the reactor equations (radial collocation is performed using simple orthogonal collocation) can be expressed in the form... 

Dominant correlations of data are usually captured by a small number of initial eigenvectors. A simple orthogonal decomposition is accomplished by partitioning U = [UmU/j] and A = [Am A ] where M designates the number of initial dominant modes to be used for approximation while R stands for the remaining N — M) modes or the residual. Data matrix becomes Y = JM- M + R- R = Ym + Yr. For a successful approximation, YM captures significant variability trends and Yr simply represents residual random noise. Transformation in the form Y Ym uses M N + K) data entries and provides [1 — M N + K)/ NK)]100 % data compression. 

To prevent contamination of the desired eigenvector by modes corresponding to overall translation or rotation, a simple orthogonalization scheme was applied both to the vector y and the derivative dX/dy. After the calculations described in this review were completed we switched all minimizations from conjugate-gradient to a new approach that is significantly faster [342]. 

When the Fickian diffusion model is used many reaction-diffusion problems in porous catalyst pellet can be reduced to a two-point boundary value differential equation of the form of equation B.l. This is not a necessary condition for the application of this simple orthogonal collocation technique. The technique in principle, can be applied to any number of simultaneous two-point boundary value differential equations. 

Population anaiysis methods of assigning charges rely on the LCAO approximation and express the numbers of electrons assigned to an atom as the sum of the populations of the AOs centered at its nucleus. The simplest of these methods is the Coulson analysis usually used in semi-empirical MO theory. This analysis assumes that the orbitals are orthogonal, which leads to the very simple expression for the electronic population of atom i that is given by Eq. (53), where Natomic orbitals centered... 

One widely used valence bond theory is the generalised valence bond (GVB) method of Goddard and co-workers [Bobrowicz and Goddard 1977]. In the simple Heitler-London treatment of the hydrogen molecule the two orbitals are the non-orthogonal atomic orbitals on the two hydrogen atoms. In the GVB theory the analogous wavefunction is written ... 

A simple illustrative example of reciprocal space is that of a 2D square lattice where the vectors a and b are orthogonal and of length equal to the lattice spacing, a. Here a and b are directed along the same directions as a and b respectively and have a length 1/a... 

The unit vectors Ci, whose exact definition, meaning and interpretation depend on the particular application at hand, are called basis vectors and form the elements of a basis. They are particularly simple to work with because they are orthogonal. This means that... 

OPW (orthogonalized plane wave) a band-structure computation method P89 (Perdew 1986) a gradient corrected DFT method parallel computer a computer with more than one CPU Pariser-Parr-Pople (PPP) a simple semiempirical method PCM (polarized continuum method) method for including solvation effects in ah initio calculations... 

How does principal component analysis work Consider, for example, the two-dimensional distribution of points shown in Figure 7a. This distribution clearly has a strong linear component and is closer to a one-dimensional distribution than to a full two-dimensional distribution. However, from the one-dimensional projections of this distribution on the two orthogonal axes X and Y you would not know that. In fact, you would probably conclude, based only on these projections, that the data points are homogeneously distributed in two dimensions. A simple axes rotation is all it takes to reveal that the data points... 

A linear coordinate transformation may be illustrated by a simple two-dimensional example. The new coordinate system is defined in term of the old by means of a rotation matrix, U. In the general case the U matrix is unitary (complex elements), although for most applications it may be chosen to be orthogonal (real elements). This means that the matrix inverse is given by transposing the complex conjugate, or in the... 

A possibly more accurate value for the double bond character of the bonds in benzene (0.46) id obtained by considering all five canonical structures with weights equal to the squares of their coefficients in the wave function. There is some uncertainty aS to the significance of thfa, however, because of- the noii -orthogOnality of the wave functions for the canonical structures, and foF chemical purposes it fa sufficiently accurate to follow the simple procedure adopted above. 

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