Template matching method

To date, two different OCR methods were implemented in CLiDE. The first one used a back-propagation neural network for classification of the characters. The character features used as input to the neural network are determined by template matching (Venczel 1993). The second OCR implementation in CLiDE is based on topological and geometrical feature analysis, and it uses a filtering technique for the classification of characters (Simon 1996). 

The method of binary template matching is equivalent to a learning network with n = 1. A binary template of a class is the superposition (Logical "and -function) of all binary encoded patterns of that class. 

Total RNA is isolated from the lymphocytes according to standard procedures and used as a template for radioactive labeled cDNA synthesis. The purified cDNA is used as probe for cDNA expression arrays. The advantages of this method as compared to other array systems are as follows (1) Radioactive-labeled probes are more sensitive than fluorescent-labeled probes and therefore need less sample RNA. (2) The primers used in the cDNA synthesis match the genes represented on the array. (3) The primer sequences are longer compared to other array systems, which increases the hybridization fidelity of RNA to the matching correct set of genes and therefore reduces mismatch reactions. 

Homology modelling is not an exact technique. Especially, when the extent of sequence homology (exact matches and matches between amino acid residues of similar property, e.g. hydrophobic, polar, acidic, basic) is low, then more attention will be paid to structural rather than sequence similarities and to prediction of structure for unmatched sequences. In such cases, and always when there is no crystal structure of a member of the family to provide a template, then total reliance has to be placed on the experience of the investigator or in one of the many computer programs now available. The principal methods have been reviewed by Sternberg (1986) and Blundell et al. (1987a). 

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