Neural-network terminology

Section of Neural units, part of Statistical learning

Neural-network terminology

Type Section
Taught in Neural units
Part Statistical learning

The next two pages differentiate these units and then train them, so the names of the weights stay fixed.

Symbol Meaning
i=1,\ldots,n observations (patterns); n_{\mathrm{tr}} training patterns, n_{\mathrm{te}} test patterns, with n_{\mathrm{tr}}+n_{\mathrm{te}}=n
j=1,\ldots,p inputs (attributes)
k=1,\ldots,m outputs (responses)
q=1,\ldots,l hidden units
x_{ij}, y_{ik} input j and correct output k of pattern i
h_{iq}, o_{ik} hidden unit q and output unit k for pattern i; o_{ik}=f_{\mathrm{network},k}(x_i)
w_{jq}, w_{qk} weight from input j to hidden unit q; from hidden unit q to output k
u_{iq}=\sum_{j=0}^{p} w_{jq} x_{ij} activation of hidden unit q for pattern i
z_{ik}=\sum_{q=0}^{l} w_{qk} h_{iq} activation of output unit k for pattern i
g(\cdot) unit activation, for example g(x)=1/(1+e^{-x})
w_{0b}, w_{0c} bias of hidden unit b and of output unit c; the extra input x_{i0} and the extra hidden unit h_{i0} are fixed at +1

Used in

See also

Artificial neuron · Perceptron learning rule · A single threshold unit cannot compute XOR · One hidden layer approximates continuous functions · History of the neural unit · Neural unit · Linear separability · Threshold unit without a bias

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