6.3 Synaptic convergence to centroids:AVQ Algorithms Unsupervised Competitive Learning (UCL) m,(t+1)=m,(t)+c,[x(t)-m(t)] m,(t+1)=,(t) fi≠j {c,}defines a slowly decreasing sequence of learning coefficient For inatane.0.000 for 10,000 samples x() Supervised Competitive Learning (SCL) m,(t+1)=m,()+c(x()x(0)-m,()] m,(t)+c,[x()-m,(t】fx∈D, m,(t)-c,[x(t)-m,(t)]if xD 2003.11.19 11
2003.11.19 11 6.3 Synaptic convergence to centroids: AVQ Algorithms Unsupervised Competitive Learning (UCL) ( 1) ( ) [ ( ) ( )] ( 1) ( ) j j j t i i m t m t c x t m t m t m t if i j + = + − + = { }t c defines a slowly decreasing sequence of learning coefficient For instance , 0.1 1 for 10,000 samples ( ) 10,000 t t c x t = − Supervised Competitive Learning (SCL) ( 1) ( ) ( ( )) ( ) ( ) ( ) [ ( ) ( )] ( ) [ ( ) ( )] j j t j j j t j j j t j j m t m t c r x t x t m t m t c x t m t if x D m t c x t m t if x D + = + − + − = − −
6.3 Synaptic convergence to centroids:AVQ Algorithms Differential Competitive Learning (DCL) m,(t+1)=m,(t)+c,AS,(y,(t)[x(t)-m,(t)] m,(t+1)=m,(t) fi≠j AS((denotes the time change of the jth neuron'scompetitive signal S AS,(y,(t)=S,(y,(t+1)-S,(y,(t) In practice we often use only the sign of the signal difference or sgn[Ay,], the sign of the activation difference. 2003.11.19 12
2003.11.19 12 6.3 Synaptic convergence to centroids: AVQ Algorithms ( ) S y j j sgn[ ] j y Differential Competitive Learning (DCL) ( 1) ( ) ( ( ))[ ( ) ( )] ( 1) ( ) j j t j j j i i m t m t c S y t x t m t m t m t if i j + = + − + = ( ( )) j j S y t denotes the time change of the jth neuron’s competitive signal ( ( )) ( ( 1)) ( ( )) = + − S y t S y t S y t j j j j j j In practice we often use only the sign of the signal difference or , the sign of the activation difference
6剖 影响迭代步长 n,t+l)=m,()+c,[x(t)-m,(t] T 终止迭代条件：m,()一m,+<c 总迭代次数 样本数 总迭代次数可以 样本数决定计算 人为设定？ 时间及精度 计算时间及精度 终止迭代的条件 可以人为设定？ 是否不需要？ 2003.11.19 13
2003.11.19 13 总迭代次数 样本数 样本数决定计算 时间及精度 总迭代次数可以 人为设定？ 终止迭代的条件 是否不需要？ 计算时间及精度 可以人为设定？ T 0 1 ( 1) ( ) [ ( ) ( )] ( ) ( 1) t j j t j j j k c c T m t m t c x t m t m t m t = − + = + − + 影响迭代步长 终止迭代条件： －