Neural net definition

1. 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.

2. The von Neumann machine and the symbolic paradigm • The operation of all conventional computers

3. 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).

4. A biological neuron

5. Artificial neurons: the TLU

6. 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