def _bumpUpWeakColumns(self):
weakColumns = numpy.where(self._overlapDutyCycles<EOL>< self._minOverlapDutyCycles)[<NUM_LIT:0>]<EOL>for columnIndex in weakColumns:<EOL><INDENT>perm = self._permanences[columnIndex].astype(realDType)<EOL>maskPotential = numpy.where(self._potentialPools[columnIndex] > <NUM_LIT:0>)[<NUM_LIT:0>]<EOL>perm[maskPotential] += self._synPermBelowStimulusInc<EOL>self._updatePermanencesForColumn(perm, columnIndex, raisePerm=False)<EOL><DEDENT>
This method increases the permanence values of synapses of columns whose
activity level has been too low. Such columns are identified by having an
overlap duty cycle that drops too much below those of their peers. The
permanence values for such columns are increased.