Pattern recognition 424 INDEX

Many other subjects are important to achieve successful pattern recognition. To name only two, it should be investigated to what extent outliers are present, because these can have a profound influence on the quality of a model and to what extent clusters occur in a class (e.g. using the index of clustering tendency of Section 30.4.1). When clusters occur, we must wonder whether we should not consider two (or more) classes instead of a single class. These problems also affect multivariate calibration (Chapter 36) and we have discussed them to a somewhat greater extent in that chapter. 

Patents Citation Index, 18 227, 238 Patent searches, 18 207-210. See also Patentability searches Patent information searches Patent specifications, searching of, 18 234 Patents Preview, 18 226, 236 PATFULL files, 18 247-248 pat gene, 13 360, 361t Pathogenic yeasts, 26 475-476 Patient package inserts (PPIs), 18 718 PATOLIS database, 18 248-249 Patternation, 23 194 of sprays, 23 187-188 Patternators, 23 188, 194 Pattern dental waxes, 8 296 Patterned electrodeposition, 9 811-832 Patterned impressions, in blood, 12 102 Pattern recognition examinations, 12 100-101... 

Witzmann FA (1994) Two-dimensional protein pattern recognition in chemical toxicity. Government Reports Announcements Index (GRA I) Issue 19 NTIS/AD-A280 359/1, p 47... 

In the molecular connectivity method, numerical indexes are developed to represent and characterize molecular structure. The indexes are suitable for use in structure-property relationships that may be developed by standard regression methods, producing equations for estimation of property values. The indexes are also used as a basis for pattern recognition and discriminant analysis. ... 

Potentiometric and refractive index detection are not affected by volume but are relatively insensitive in the nanolitre to picolitre range compared to amperometric detection (micro surface area) and fluorimetric detection (micro amount of material). At 1 pL, limits of detection are similar for potentiometry, amperometry and fluorescence. On-chip LC is very compatible with mass spectrometry due to the low volumes and flow rates required. Battery-operated ion trap MS has been reported but miniaturisation of MS offers no sensitivity or selectivity advantages. Electrospray ionisation (ESI) has been successfully integrated into a chip format allowing for many ESI nozzles on one chip. Arrays make pattern recognition possible. 

A comprehensive list of literature references, an author and subject index should facilitate a retrieval of detailed and original information about pattern recognition in chemistry. All cited literature except a few has been used in original form. 

The second and third means of collecting multiple spectra involve collection from numerous locations within the vessel at one or more times. Multiple spectra drawn at one time from various locations in a blender may be compared to themselves or to spectra collected at different times, with similarity indicating content uniformity. Parameters for comparison can again include common statistical factors such as standard deviation, relative standard deviation, variance, a host of indexes based on standard deviation, or the results from pattern recognition routines. Of course, spectra collected in this manner can also be compared to a library of spectra from previous homogenous blends. 

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