Sigmoidal Functions Logistic function: Increasing a p(y）=1+e-y where 108642246810 ∑ WjiXi i=1 v is the induced field of neuron j oSigmoidal functions is the general form of activation function ●a→o→p→threshold function Sigmoidal functions is differentiable 9177Sigmoidal Functions Logistic function: φ(vj) = 1 1 + e −avj where vj = Xm i=1 wjixi vj is the induced field of neuron j Sigmoidal functions is the general form of activation function a → ∞ ⇒ φ → threshold function Sigmoidal functions is differentiable 9 / 77