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NN applications. Mortage risk evaluator appraises underwriting process Deliquency risk mortage origination mortage insurance Assessment underwriting underwiriting
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NN applications • Mortage risk evaluator appraises underwriting process Deliquency risk mortage origination mortage insurance Assessment underwriting underwiriting • Clean up noise on telephone lines and reduce transmission errors on modems (adaptive filters). • SNOOPE – bomb detector system at JFK. Detect explosives based on γ – ray emissions. • Airline Marketing Tactician (AMT) advices seat yield management.
Hopfield Nets(Associative Memories) Wij = Wji -1 -1 1 3 -1 1 -2 3 2 1 -1 Si = sgn(Σ Wij Sj ) j Si =Activation of node i Sgn(X) = 1, x>=0 -1, x<0
Parellel relaxation • Stable states
Memorize patterns: ξμ , μ= 1,2,…,p • Where ξμ = (ξ1μ , …., ξNμ ) Σμ • Attractors (net nodes labeled 1,…,N) Learning Rule: Hebb rule: Wij= (1/N) * Σ ξiμ ξjμ p μ = 1 • Asynchronus unitupdating • To recall perfectly p attractors with N units • P= N/ (4 log N)
To train hopfield 1 2 To stroe pattern Wij =1 if both states have same activation = -1 otherwise 4 3 5 7 6
To train hopfield (contd..) = W1 1 2 3 4 5 6 7 • 0 -1 1 -1 0 0 0 • 0 0 1 0 0 0 • 0 -1 1 1 0 • 0 0 -1 1 • 0 1 0 • 0 -1 • 0 Total net weights: W = W1 +W2 +… One matrix per pattern