Issue No. 11 - November (1994 vol. 43)
ISSN: 0018-9340
pp: 1329-1333
ABSTRACT
<p>An additive fuzzy system can uniformly approximate any real continuous function on a compact domain to any degree of accuracy. An additive fuzzy system approximates the function by covering its graph with fuzzy patches in the input-output state space and averaging patches that overlap. The fuzzy system computes a conditional expectation E|Y|X| if we view the fuzzy sets as random sets. Each fuzzy rule defines a fuzzy patch and connects commonsense knowledge with state-space geometry. Neural or statistical clustering systems can approximate the unknown fuzzy patches from training data. These adaptive fuzzy systems approximate a function at two levels. At the local level the neural system approximates and tunes the fuzzy rules. At the global level the rules or patches approximate the function.</p>
INDEX TERMS
neural nets; function approximation; curve fitting; fuzzy set theory; universal approximators; additive fuzzy system; fuzzy patches; input-output state space; conditional expectation; commonsense knowledge; state-space geometry; statistical clustering systems; training data; neural system; fuzzy rules.
CITATION

B. Kosko, "Fuzzy Systems as Universal Approximators," in IEEE Transactions on Computers, vol. 43, no. , pp. 1329-1333, 1994.
doi:10.1109/12.324566