Classification of Materials and Chemical Compounds
The origin of materials can often be classified by analyzing the contents of trace elements. The pattern of concentrations is caused by the raw materials which are used and by the production process, e.g. the trace elements in paper samples stem from wood, process water and other materials and substances used during the production. Duewer and Kowalski  used the concentrations of ten elements (Na, Al, Cl, Ca, Ti, Cr, Mn, Zn, Sb, Ta) — determined by neutron activation analysis — to characterize a paper sample, A set of 119 different sheets of papers from nine manufacturers have been classified by several pattern recognition methods. Classifiers were computed to recognize both the manufacturer and the paper grade. The concentration of aluminum was found to be very characteristic of paper samples. A simple feature by feature plot (concentration of aluminum versus concentration of manganese) revealed well defined groups of manufacturers. All attempts to find natural groups other than paper grade and manufacturers were unsuccessful.
KeywordsFeature Selection Neutron Activation Analysis Paper Sample Pattern Recognition Method Pattern Recognition Technique
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