Neural net definition A Neural Network is an interconnected

assembly of simple processing elements, units or nodes, whose functionality is loosely based on the animal neuron.

The processing ability of the network is stored in the inter-unit connection strengths, or weights and/or function of processing element.

Network organization is obtained by a process of adaptation to, or learning from, a set of training patterns.

The von Neumann machine and the symbolic paradigm The operation of all conventional

computers

Cycle of events in a computer

1. fetch an instruction from memory. 2. fetch any data required by the

instruction from memory. 3. execute the instruction (process

the data). 4. store results in memory. 5. go back to step 1).

A biological neuron

Artificial neurons: the TLU

Artificial neurons: the TLU We suppose there are n inputs with signals

and weights . The signals take on the values `1' or `0' only. That is the signals are Boolean valued. (This allows their relation to digital logic circuits to be discussed). The

activation a, is given by

This may be represented more compactly as