Accuracy index

The accuracy index, the untransformed average bias and the statistical variation in... 

Table 8.4 reports the overall accuracy of the predictions. A wider range of measures of the predictive ability can be calculated (e.g., sensitivity, specificity, etc.), but the overall accuracy index... 

Process Tech- nology Product Process Effi- ciency % Maturity Accuracy Index Capital cost k /TJ annum capacity 100% utilisation ie. C Opportunity cost/ GJ ie. A Feedstock price range /GJ ie. B Comment Ref. 

Peak area accuracy indexes mean of (A — A /s for which the target is 0, and the standard deviation,... 

The accuracy of such cost extrapolation tends to decrease with the length of time involved. Various important U.S. cost indexes are the M S Index, CE Plant Cost Index, Nelson Constmction Cost Index, and the ENR Constmction Index. Similar indexes are available for other countries. 

Direct or indirect methods may be used to determine moisture in dehydrated foods. Indirect methods must be calibrated in terms of direct methods—the most common of which are the oven, distillation, and Fischer methods. Accuracy of the direct methods is difficult to evaluate except by comparison with a chosen reference method. Several reference methods are reviewed, but none can be given an unqualified recommendation as most practical and suitable for all foods. An indirect measure of moisture is the equilibrium vapor pressure of water, which can be measured easily and accurately. Arguments are presented to show that vapor pressure may be a better index of the stability of dehydrated foods than the moisture content, which has been frequently used for this purpose. 

It is seen that, for a truly linear detector, the response index (a) will be unity and the experimentally determined value of (a) will be an accurate measure of the proximity of the response to strict linearity. It is also clear that (a) could be used to correct for any non-linearity that might occur in the detector and thus improve the accuracy of an analysis. 

The entries of this index were derived directly by computer program from the lists of references. The accuracy of the references was the sole responsibility of the authors. No editorial check, except for format and journal-title abbreviation, was applied. Consequently, errors occurring in authors names in the references will recur in this index. 

Apparently, the main idea behind this approach needs certain clarification. For example, formula (38) necessitates imposing a nonzero background temperature prior to the front. In spite of this fact, there are some delays in introducing new intervals, thus causing large deviations of a solution in a vicinity of the front. Formula (37) is useless for very large values of the index cr a > 20). Formula (36) has the best accuracy and reproduces rather accurately without concern of the background temperature. 

It is essential that the solution be sufficiently dilute to behave ideally, a condition which is difficult to meet in practice. Ordinarily the dilutions required are beyond those at which the concentration gradient measurement by the refractive index method may be applied with accuracy. Corrections for nonideality are particularly difficult to introduce in a satisfactory manner owing to the fact that nonideality terms depend on the molecular weight distribution, and the molecular weight distribution (as well as the concentration) varies over the length of the cell. Largely as a consequence of this circumstance, the sedimentation equilibrium method has been far less successful in application to random-coil polymers than to the comparatively compact proteins, for which deviations from ideality are much less severe. 

Besides the elementary properties of index permutational symmetry considered in eq. (7), and intrinsic point group symmetry of a given tensor accounted for in eqs. (8)-(14), much more powerful group-theoretical tools [6] can be developed to speed up coupled Hartree-Fock (CHF) calculations [7-11] of hyperpolarizabilities, which are nowadays almost routinely periformed in a number of studies dealing with non linear response of molecular systems [12-35], in particular at the self-consistent-field (SCF) level of accuracy. 

Beyond the parameter sets, described above, a steric index, Hj, is introduced, which represents the steric hindrance of the ith atom by other atoms in the molecule. By definihon, the H value of the ith atom ranges from a minimum value of 0 to a maximum value of 1 proportional to its shielding by all other atoms of the molecule. Thus, a funchonal group next to large subshtuents will weakly contribute to the eshmated log P. Including the steric index yields a small, but significant improvement in model accuracy. 

The refiractive index (1-3000 to 1-7000) may be read directly on a scale with accuracy of about 0 - 0002. 

Disclaimer. We cannot guarantee for the correctness of the above tables. When accuracy is very important, we recommend using instead the NIST website http //physics.nist.gov/cuu/Constants/index.html... 

The HcReynolds abroach, which was based on earlier theoretical considerations proposed by Rohrschneider, is formulated on the assumption that intermolecular forces are additive and their Individual contributions to retention can be evaluated from differences between the retention index values for a series of test solutes measured on the liquid phase to be characterized and squalane at a fixed temperature of 120 C. The test solutes. Table 2.12, were selected to express dominant Intermolecular interactions. HcReynolds suggested that ten solutes were needed for this purpose. This included the original five test solutes proposed by Rohrschneider or higher molecular weight homologs of those test solutes to improve the accuracy of the retention index measurements. The number of test solutes required to adequately characterize the solvent properties of a stationary phase has remained controversial but in conventional practice the first five solutes in Table 2.12, identified by symbols x through s have been the most widely used [6). It was further assumed that for each type of intermolecular interaction, the interaction energy is proportional to a value a, b, c, d, or e, etc., characteristic of each test solute and proportional to its susceptibility for a particular interaction, and to a value x, X, Z, U, s, etc., characteristic of the capacity of the liquid phase... 

The cost of a unit is then obtained from Figure 9-4. To obtain the cost of the plant this figure needs to be multiplied by the number of units, a factor (1.33) to account for utilities and general facilities, and the current or projected value of the Engineering News Record Chemical Cost Index. The accuracy of this method is unknown but should be better than the Lang factor and not as good as Miller s. 

There exist two geometrically different varieties of these sites, which are referred to as B5 sites because both can be made to accommodate a nitrogen molecule, which is then coordinated by five atoms. They occur at steps on the (100) and (111) planes, and particularly on (110), (311), and other high-index planes. A later paper by van Hardeveld and van Montfoort (10) contains additional evidence showing that the B5 sites are indeed responsible for the infrared-active form of nitrogen adsorption, and also that the number of B5 sites in the sample can be estimated with fair accuracy from the intensity of the 2200 cm-1 band. This means that infrared study of nitrogen adsorption can give valuable information about the structure of the surface of metal particles. 

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