Regressional analysis

An increment system has been derived for methyldecalins [230] and methylated perhy-drophenanthrenes [231] by regressional analysis, because these compounds are steroid models and the increments, in fact, have proved to be of help in carbon-13 shift assignments of steroids (Section 5.2). Eq. (4.2) permits prediction of <5C using the increments A, of structural elements in position l to the carbon atom k to be considered (Table 4.9). These increments clearly indicate the configurational influence of the y substituent, decreasing for example from eclipsed via gauche to trans interactions (I , > Vq > Vt and... 

Apply some form of regressional analysis to the non-selective Ri-values. 

There are a number of ways of using the regressional analysis method and the simplest, and for many purposes the most powerful of these can be illustrated with respect to the determination of the relaxation contributions which the anomeric proton of thegalactopyranose residue of V receives from the protons of the fructofuranose ring. The non-selective Ri-values... 

Results from regressional analysis show that the rate constant (k) is 2.62 X 10 2 mM/min and the adsorption coefficient (K) is 6.43 mM-1. 

The components from the various trials need to be assiduously tested against the customer s specifications. Some components may have different measured properties. This will only be resolved throngh regressional analysis of the results from the factorial experiments. Happily, there are a number of commercially available compute-based packages that will assist the technologist in this task. 

The functional behavior at large shear rates on the same log-log plot in Fig. 2.16, being linear defines K and n directly. The slc of the straight line defines n - 1, and is the value of when if = 1 (provided the point satisfies the power-law equation). The best values of K and r — 1 can be computed easily by regressional analysis of the data at higher shear rates. 

The B -B, L parameters have at least two important advantages in comparison to other steric parameters (i) they describe more adequately nonsymmetrical substituents and emphasize the directional (vectorial) character of steric effects, extending thus the possibilities of OSAR analysis, (ii) they offer more detailed information about the actual conformation of the receptor when it is attacked by the effector. Nevertheless, the fact that it introduces at once five predictor variables in the regressional analysis requires relatively large series of data in order to obtain reliable results. 

Multiparametric regressional analysis. Equations (7) and (0) are derived with the corresponding statistics ... 

Cohen, J. and Cohen, P. (1975) Applied Multiple Regressional/Correlation Analysis for the Behavioral Sciences, (Hillsdale, NJ Lawrence Erlbaum), pp. 123-167 Cornfield, J. (1974) Recent methodological contributions to clinical trials. Am. ]. Epidemiol, 104, 408-421... 

The utilization of Equation (1) is conditioned by its statistical quality. Usually, regressional equations are characterized by correlation coefficient Cr) and standard deviation Cs, These two parameters do not allow a complete analysis of the quality of equations. It is necessary to use also other criteria such as the values of F (Fischer statistics), t (Student statistics), and EV (explained variance), ... 

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