Competitive learning law

Learning in neural networks happens by associative or competitive learning laws. In this context, learning means the following ... 

The learning algorithm for the Kohonen net operates in analogy to the competitive learning laws in Eqs. 8.19-8.21 ... 

What makes the difference between an associative and competitive learning law ... 

A lesson to learn from this analysis is that the concept of the rate-determining step is rather subtle. Thus, in the diffusion-controlled limit, the condition for the encounter rate to be rate determining is not that it is the slowest step, but that the reaction rate of the encounter pair is much greater than the rate at which the pair breaks up. In the activation-controlled limit, the condition for the rate of energy accumulation to be rate determining is likewise a competition between the rate of reaction of the pair and the rate at which it breaks up, and all three rate constants contribute to the overall rate. The best way to analyze competing rates is to do as we have done here to set up the overall rate law and then to analyze how it simplifies as we allow particular elementary processes to dominate others. 

Recendy more detailed studies on the cyclopropane fatty acid synthetase have been reported (Chung and Law, 1964b). Further pu -cation of the synthetase resulted in an apparent decrease in enzyme activity. However this was shown to be due to the removal of an enzyme capable of hydrolyzing one of the end products of the reaction, S-adenosylhomocysteine. This compound is a potent competitive inhibitor of die methylene addition reaction. It will be of interest to learn whether or not S-adenosylhomocysteine hydrolase plays a physiological role in the marked increase in the rate of cyclopropane fatty acid synthesis that has been observed in vivo during the later stages of growth (see Section III,A). 

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