28. The non-transitory computer-readable medium of claim 27 , wherein identifying unrelated concepts comprises: determining a revised score for each local concept; determining said ranked global list of all local concepts based on the revised scores; removing local concepts whose combined revised score contributes less than a predetermined amount of a total score of the global list to produce a resulting list; identifying unrelated regions without a most relevant local concept on the resulting list; and removing local concepts expressed in the unrelated regions from the resulting list to produce a list of relevant concepts.
28. The non-transitory computer-readable medium of claim 27 , wherein identifying unrelated concepts comprises: determining a revised score for each local concept; determining said ranked global list of all local concepts based on the revised scores; removing local concepts whose combined revised score contributes less than a predetermined amount of a total score of the global list to produce a resulting list; identifying unrelated regions without a most relevant local concept on the resulting list; and removing local concepts expressed in the unrelated regions from the resulting list to produce a list of relevant concepts. 29. The non-transitory computer-readable medium of claim 28 , wherein determining the source meaning comprises normalizing the revised scores for the relevant concepts.