Research On The Ranking Of Mathematical Retrieval Results Based On Hesitant Fuzzy Sets

As the increasing number of documents in the network,people's demand of searching information is increasing.The mathematical formula is an important part of most web documents,through which people search mathematical formulae and documents from the mathematical search engine.However,the retrieval requirements of people are still difficult to satisfy.Ranking the results of mathematical search engine is difficult resulted from the twodimensional structure and the complexity grammatical features of the mathematical formulae.Aiming at this problem,we put forward a method for ranking the mathematical search engine results,which contained mathematical formulae or documents.Taking advantages of the hesitant fuzzy sets in dealing with problems with multi feature and memberships,this thesis achieved to the orderly output of the results of mathematical search engine based on calculating the similarity between mathematical formulae and constructing the document ranking function.Through extracting and analyzing the characteristics of the mathematical formulae,the mathematical formulae evaluation attributes set was constructed.Then,the membership function of each evaluation index was defined and each mathematical expression was converted into the corresponding fuzzy set.Based on the theory of hesitant fuzzy sets,the similarity of mathematical formulae was calculated.On the basis,this thesis also analyzed the characteristics of the documents in the network,constructed the evaluation attribute sets and the corresponding membership functions of documents and designed the document ranking function.Comparing with the existing ranking method,experiment showed that the proposed method was efficiency in ranking mathematical search engine results.