AFLAB 1 full-auto Yes none CLAIM DOC,DOCNO,TITLE,ABST,SPEC,CLAIM NTCIR-6 sample topics word part-of-speech tagging inverted file word OKAPI BM25 TF.IDF none AFLAB 2 full-auto No none CLAIM DOC,DOCNO,TITLE,ABST,SPEC,CLAIM,CITATION NTCIR-6 sample topics word part-of-speech tagging inverted file word OKAPI BM25 TF.IDF none AFLAB 3 full-auto No none CLAIM DOC,DOCNO,TITLE,ABST,SPEC,CLAIM,CITATION NTCIR-6 sample topics word part-of-speech tagging inverted file word OKAPI BM25 TF.IDF none JSPAT 1 full-auto Yes EN CLAIM DOC,DOCNO,TITLE,ABST,SPEC,CLAIM none word morphological analysis inverted file word vector space model TF.IDF and log TF none JSPAT 2 full-auto Yes EN CLAIM DOC,DOCNO,TITLE,ABST,SPEC,CLAIM none word morphological analysis inverted file word vector space model TF.IDF and log TF none JSPAT 3 full-auto No EN CLAIM,APP-DATE DOC,DOCNO,TITLE,ABST,SPEC,CLAIM none word morphological analysis inverted file word vector space model TF.IDF and log TF none JSPAT 4 full-auto No EN CLAIM,APP-DATE DOC,DOCNO,TITLE,ABST,SPEC,CLAIM none word morphological analysis inverted file word vector space model TF.IDF and log TF none KLE 1 full-auto EN CLAIM TITLE, ABST, SPEC, CLAIM Sample topics for parameter optimization word as-is, Porter stemming Inverted file word Language Model Term Frequency, Document Length, Collection Frequency, Collection Length none NTNU 1 full-auto Yes EN INVENTOR, TITLE, ABST, CLAIM, some use SPEC INVENTOR, TITLE, ABST, CLAIM none 1-gram, 2-gram indexing, and key-phrase formulation. Thus the index terms include single characters, all 2-word and repeated words/phrases unregistered in the dictionary. a phrase formulation technique based on repeated sequence extraction to combine unsegmented characters or words into new words or phrases. inverted file 1-gram, 2-gram indexing, and key-phrase formulation. Thus the index terms include single characters, all 2-word and repeated words/phrases unregistered in the dictionary. probabilistic model TF/IDF pseudo feedback hcu 1 full-auto Yes CLAIM tag TITLE,ABST,SPEC,CLAIM NTCIR 6, sample Word morphological analysis GETA Word vector space model SMART query expansion based on a related term dictionary, which was automatically constructed from a patent database. hcu 1 full-auto Yes CLAIM tag TITLE,ABST,SPEC,CLAIM NTCIR 6, sample Word morphological analysis GETA Word vector space model SMART query expansion based on a related term dictionary, which was automatically constructed from a patent database.