9. The method of claim 2 , wherein the generating of the theme vector by assigning the feature value of the selected feature comprises assigning the feature value of the feature by using binary numbers.
9. The method of claim 2 , wherein the generating of the theme vector by assigning the feature value of the selected feature comprises assigning the feature value of the feature by using binary numbers. 10. The method of claim 9 , wherein the assigning of the feature value of the feature by using binary numbers comprises: establishing a binary 1 as the feature value when the respective feature corresponds to a relevant theme; establishing a binary 0 as the feature value when the respective feature does not correspond to the relevant theme; and generating the theme vector based on the established feature value.