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ID:28065090
大小:161.00 KB
页数:20页
时间:2018-12-07
《基于lucene相似句子检索系统论文英文翻译原文》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、AnalysisAnalysis,inLucene,istheprocessofconvertingfieldtextintoitsmostfundamentalindexedrepresentation,terms.Thesetermsareusedtodeterminewhatdocumentsmatchaqueryduringsearches.Forexample,ifthissentencewereindexedintoafield(let’sassumetypeField.Text),thet
2、ermsmightstartwith/^randexample,andsoon,asseparatetermsinsequence.Ananalyzerisanencapsulationoftheanalysisprocess.Ananalyzertokenizestextbyperforminganynumberofoperationsonit,whichcouldincludeextractingwords,discardingpunctuation,removingaccentsfromchara
3、cters,lowercasing(alsocallednormalizing),removingcommonwords,reducingwordstoarootform(stemming),orchangingwordsintothebasicform(lemmatization).Thisprocessisalsocalledtokenization,andthechunksoftextpulledfromastreamoftextarecalledtokens.Tokens,combinedwit
4、htheirassociatedfieldname,areterms.Lucene’sprimarygoalistofacilitateinformationretrieval.Theemphasisonretrievalisimportant.YouwanttothrowgobsoftextatLuceneandhavethemberichlysearchablebytheindividualwordswithinthattext.InorderforLucenetoknowwhat“words”ar
5、e,itanalyzesthetextduringindexing,extractingitintoterms.Thesetermsaretheprimitivebuildingblocksforsearching.ChoosingtherightanalyzerisacrucialdevelopmentdecisionwithLucene.Onesizedoesn’tfitallwhenitcomestochoosingananalyzer.Languageisonefactorinchoosinga
6、nanalyzer,becauseeachhasitsownuniquefeatures.Anotherfactortoconsiderinchoosingananalyzeristhedomainofthetextbeinganalyzed;differentindustrieshavedifferentterminology,acronyms,andabbreviationsthatmaydeserveattention.Althoughwepresentmanyoftheconsideration
7、sforchoosinganalyzers,nosingleanalyzerwillsufficeforallsituations.It’spossiblethatnoneofthebuilt-inanalysisoptionsareadequateforyourneeds,andyou’llneedtoinvestincreatingacustomanalysissolution;pleasantly,Lucene’sbuildingblocksmakethisquiteeasy.Oneofthebe
8、stquestionsyoucanaskasyoucontemplatetheanalysisprocessis,“WhatwouldGoogledo?”Google’sactualalgorithmsareproprietaryandkeptrelativelysecret,buttheresultsfromsearchesgivesomeinsight.Searchingforthephrase“tobeornottobe”withan
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