基于PCA與SVM的早稻稻瘟病預(yù)測方法研究.pdf

1、獨創(chuàng)性聲明本人聲明所呈的學(xué)位論文是本人在導(dǎo)師指導(dǎo)下進行的研究工作及取得的研究成果。據(jù)我所知，除了文中特別加以標注和致謝的地方外，論文中不包含其他人已經(jīng)發(fā)表或撰寫過的研究成果，也不包含為獲得安徽農(nóng)業(yè)大學(xué)或其他教育機構(gòu)的學(xué)位或證書而使用過的材料。與我一同工作的同志對本研究所做的任何貢獻均已在論文中作了明確的說明并表示謝意。學(xué)位論文作者簽名：簽字日期：∥嚴年舌學(xué)位論文版權(quán)使用授權(quán)書本學(xué)位論文作者完全了解安徽農(nóng)業(yè)大學(xué)有關(guān)保留、使用學(xué)位論文的規(guī)定

2、，有權(quán)保留并向國家有關(guān)部門或機構(gòu)送交論文的復(fù)印件和電子文件，允許論文被查閱和借閱。本人授權(quán)安徽農(nóng)業(yè)大學(xué)可以將學(xué)位論文的全部或部分內(nèi)容編入有關(guān)數(shù)據(jù)庫進行檢索，收錄到《中國學(xué)位論文全文數(shù)據(jù)庫》，可以采用影印、縮印或掃描等復(fù)制手段保存、匯編學(xué)位論文，向社會公眾提供信息服務(wù)。(保密的學(xué)位論文在解密后適用本授權(quán)書)。學(xué)位論文作者簽名：簽字日期：加／眸學(xué)位論文作者畢業(yè)后去向：工作單位：通信地址：指導(dǎo)教師簽名：辜五!13p簽字日期：滬，9年‘月；口電

3、話：郵編：AbstractRiceisoneofthestaplefoodcropsinChinawithawide鏟owingareacoveringaboutaquarterofthetotalfarmlandneannualriceproductionalsomakesupalmosthalfofthetotalnationalgrainoutputThericeblastisoneoftheseriousdiseasesaffe

4、ctingthehighandstableyieldsofriceInrecentdecades，thelossofplantingareashasbeenmore。thanthreemillionhectaresandthedecreaseofgrainhasalsocometotensofmillionstoneveryyearHowtoaccuratelyforecastthericeblastintimeandtakemeasu

5、restopreventpesthavealreadybeenthebasicworktocontrolthericeblastdiseaseandsecurethesafetyofficeefficiently‘1Basedonweatherconditions，thispaperstudiesonforecastingmethodsoftheearlyriceblastItmakesexperimentsinTonglingPuJi

6、weifarmAccordingtothebiologicalpropertiesandmeteorologyprincipleofriceblast，thispaperchoosestheprincipalcomponentanalysis(PCA)toanalyzethemainmeteorologicalfactorsaffectingtheoccurrenceofriceblastThroughthismethod，thepap

7、erselectsandanalyzesthemainmeteorologicalfactorsaboutthedegreeofriceblastItfindsthattherateofcontributionsofthepreviousfourmaincomponentshasalreadyreached81percentconformingtothestandardofextractingmaincomponentsByobserv

8、ingthepreviousfourmaincomponents，thispaperdiscoversthatthemeteorologicalfactors，suchasamountsanddaysofprecipitation，temperature，heliometricindex，relativehumidityandSOon，playavitalroleinthedegreeoftheoccurrenceofearlyrice

9、blastEspeciallytheamountofprecipitationasthedecisivemeteorologicalfactordirectlyinfluencestheforming，dyeingandspreadingofthebacteriaoftheearlyriceblastGenerallyspeaking，thelongandcontinuousrainydaysarethepeakperiodsofthe

10、happeningofearlyriceblastThispaperstartsfromextractingthemaincomponentsofmeteorologicalfactorsfromenvironmentbythemethodofPeAThenreferringtothelevelsofearlyriceblastineachyearthispaperusesSVMtoestablishtheforecastingmode

11、lofthedegreeoftheearlyriceblastTheauthortakesthedataofTonglingPuJiweifarmasthetrainingsamplesfrom1991t02002andfrom2005to2006，andusestheLIBSVMtoolboxofMATLABtoforecastandanalyzeAftertha_t，theauthorappliestheactualdatafrom

12、2003to2004andfrom2007to2010tochecktheforecastingefficiencyofthemodel，findingthattherateofaccuracyashighas83percentAsaresult，onthebasisofPeAandSVM，theforecastingmodelaimingatthemeteorologicalfactorsisofhighfeasibilityandq