Boltzmann Machine - Equilibrium State

Equilibrium State

The network is run by repeatedly choosing a unit and setting its state according to the above formula. After running for long enough at a certain temperature, the probability of a global state of the network will depend only upon that global state's energy, according to a Boltzmann distribution. This means that log-probabilities of global states become linear in their energies. This relationship is true when the machine is "at thermal equilibrium", meaning that the probability distribution of global states has converged. If we start running the network from a high temperature, and gradually decrease it until we reach a thermal equilibrium at a low temperature, we may converge to a distribution where the energy level fluctuates around the global minimum. This process is called simulated annealing.

If we want to train the network so that the chance it will converge to a global state is according to an external distribution that we have over these states, we need to set the weights so that the global states with the highest probabilities will get the lowest energies. This is done by the following training procedure.

Read more about this topic:  Boltzmann Machine

Famous quotes containing the words equilibrium and/or state:

    That doctrine [of peace at any price] has done more mischief than any I can well recall that have been afloat in this country. It has occasioned more wars than any of the most ruthless conquerors. It has disturbed and nearly destroyed that political equilibrium so necessary to the liberties and the welfare of the world.
    Benjamin Disraeli (1804–1881)

    Resorts advertised for waitresses, specifying that they “must appear in short clothes or no engagement.” Below a Gospel Guide column headed, “Where our Local Divines Will Hang Out Tomorrow,” was an account of spirited gun play at the Bon Ton. In Jeff Winney’s California Concert Hall, patrons “bucked the tiger” under the watchful eye of Kitty Crawhurst, popular “lady” gambler.
    —Administration in the State of Colo, U.S. public relief program (1935-1943)