简介：

简介：Atmosphericconcentrationsofpolycyclicaromatichydrocarbons(PAHs)weremeasuredduringvariousseasonsatsixdifferentcities/locationsinQingdaoalongshore.TheannualaveragePAHsconcentrationrangedfrom16ng/m3(atacleancom-paredsite)to308ng/m3(inanindustrysite).TheaveragetotalparticulatePAHsconcentrationwas74.5ng/m3withahigherconcentrationofparticulatePAHsinwinter.Basedonayear-rounddataset,thesourcesofPAHsintheairofQingdaoweredrawnbyprincipalfactoranalysisandcorrelationanalysis.TheresultsindicatedthatvehicleemissionsandoilburningwerethemainsourceofPAHsinQingdaoalongshore.

简介：Theexpertsystemforstatisticalpredictionofmineraldepositsonmiddleandlargescalestakesthesystemofscientificexplorationtheories,criteriaandmethodsproposedbyProfessorZhaoPengdaasthefieldexpertknowledge.Atpresentthedevelopedsystemfocusesontwoaspects:syntheticexplorationandquantitativeexploration.Amongthethreebasictheoriesforthepredictionofdeposits,ithighlightstheapplicationsofseekinganomalytheory.Thissystemischaracteristicinthedeterminationofgeologicalbackground,thestudyofgeologicalanomaliesandthedelineationofgeologicalbackground,thestudyofgeologicalanomaliesandthedelineationofmineralizationanomalies.Thesystemcombinescloselytheknowledgebase,methodbaseanddatabase,integratestheinputandoutputinformationofmulti-sourcesandmulti-variables,data,graphsandimagineprocessingsystemandinquiringsystemasawhole.Sothesystemcanmeetingeneralallkindsofdemandsinstatisticalpredictionofm

简介：平常的微分方程颂诗广泛地被使用确定HIV病毒的动力学。从吵闹的数据估计颂诗参数有趣却挑战性，特别数据有一些孤立点。在这研究，作者使用吝啬的移动孤立点模型MSOM基于颂诗的二拍子的圆舞评价在HIV模型检测孤立点。为移动参数的近似公式被导出。而且，20个测试统计数值被构造，它的接近的分发被建立。模拟结果显示出那：1边界点相对内部点在参数评价上有更多的影响。2建议过程能有效地检测孤立点。作者从HIV临床的试用用一个申请例子说明建议途径并且发现到模拟的类似的模式学习。

简介：AstatisticalanalysisoftectonicenvironmentforM≥6.0strongearthquakesinChina'scontinentsincethebeginningofrecordedhistoryisperformedbasedonthedataofactivefaultsstudiedduringlast10yearsandresultofcompilationofthefourthversionoftheMapofSeismicRegionalizationofChinaforEarthquakeProtection.Tectonictypesofseismicsourcesofstrongearthquakesinallseismicregionsandthemovementmodesofseismogenicstructuresarediscussed.Meanwhile,ananalysisoflengthsofsurfacerupturezonesproducedbyalltypesofearthquakes,orientationsoflongaxesofmeizoseismalareas,regionaltectonicstressfieldsinseismicsourceregionsforstrongearthquakes,geophysicalfields(gravityanomaly,highconductivitylayeranomaly,andterrestrialheatflowdensity),andrecentverticalcrustaldeformationfieldshavebeencarriedout.

简介：

简介：Identificationofmodalparametersofalinearstructurewithoutput-onlymeasurementshasreceivedmuchattentionoverthepastdecades.Inthepaper,theNaturalExcitationTechnique(NExT)isusedforacquisitionoftheimpulsesignalsfromthestructuralresponses.ThenEigensystemRealizationAlgorithm(ERA)isutilizedformodalidentification.(SAMFM),isdevelopedtodistinguishthetruemodesfromnoisemodes,andtoimprovetheprecisionoftheidentifiedmodalfrequenciesofthestructure.Anoffshoreplatformismodeledwiththefiniteelementmethod.Thetheoreticalmodalparametersareobtainedforacomparisonwiththeidentifiedvalues.ThedynamicresponsesoftheplatformunderrandomwaveloadingarecomputedforprovidingtheoutputsignalsusedforidentificationwithERA.Resultsofsimulationdemonstratethattheproposedmethodcandeterminethesystemmodalfrequencywithhighprecision.

简介：

简介：Ｅｆｆｅｃｔ　ｏｆ　Ｌａｎｇｅｖｉｎ　Ｓｔａｔｉｓｔｉｃａｌ　Ｆｌｕｃｔｕａｔｉｏｎｓ　ｏｎ　Ｈｅａｖｙ－ｉｏｎ　Ｉｎｄｕｃｅｄ　Ｆｕｓｉｏｎ　ＲｅａｃｔｉｏｎＥｆｆｅｃｔｏｆＬａｎｇｅｖｉｎＳｔａｔｉｓｔｉｃａｌＦｌｕｃｔｕａｔｉｏｎｓｏｎＨｅａｖ...

简介：在热带气旋(TC)的最近的趋势和可变性频率和紧张为影响了中国的TC被检验，与影响的那些TC的特别焦点，瓷器给经济地区调音(例如，长江三角洲，珀尔河三角洲，和北京天津区域)。结果证明微弱地影响中国的TC的频率在1980年代和2000年代期间衰退了，由细微增加列在后面。TC频率的时间系列在过去的60年期间在26年的时期显示出不足道的变化；这些变化显著地与ENSO活动被相关。当影响长江三角洲的TC的频率不是时，影响珍珠河三角洲区域的TC的频率强烈与ENSO周期被相关。TC频率为不同紧张的TC不同地变化。影响中国的热带暴风雨(TS)在全部的数字是小的，但是清楚地在频率增加了。严重热带暴风雨(圣)的频率，台风(TY)，严重台风(猪圈)，和影响中国的超级台风(超级TY)在1970年代期间显著地衰退了，猪圈和超级TY的1980年代，而是数字在2000年代上增加了。影响中国的TC的典型紧张在60年的timeframe上衰退了，但是在最近的10年(20002010)增加了。TC的紧张的这增加特别地影响了长江三角洲区域，它经历了猪圈和超级TY的增加的数字。这些趋势特别地在完整的60年的分析时期和最近的10年的时期期间在一般来说影响两个中国的TC和长江三角洲的最大的紧张的变化被观察；然而，这些趋势没在TC的平均紧张的变化被观察。由对比，极端紧张和影响珍珠河三角洲的TC的平均紧张在整个分析时期减少了，包括最近的十年。

简介：损坏结构的碎片引起的危险在意外爆炸或敌对强风事件通常是重要的。估计可能的碎片尺寸，速度和发射距离的一个可靠、有效的方法将是有用的估计并且设计反措施减轻可能的碎片危险。这篇论文为预言尺寸和石工技术墙的爆炸损坏引起的碎片的发射距离论述一个数字方法。有不同放大距离的数字模拟被执行，并且碎片的统计分发功能缩放，发射距离以放大距离被导出。

简介：ThispaperisrelatedtostudyoftheiondensityrecordedbythelowaltitudesatelliteDEMETER.Itwillpresentionosphericperturbationsobservedduringlargeseismicevents.Astheionosphereishighlyvariable,thepaperwillshowastatisticalanalysisperformedontheplasmaparametersduringnighttime.Analgorithmhasbeenimplementedtodetectcrestsandtroughsinthedatabeforeworld-wideearthquakes.Theearthquakeshavebeenclassifieddependingontheirmagnitude,depth,andlocation(land,belowthesea,closetoacoast).Duetotheorbit,DEMETERreturnsabovethesameareaeveryday(onceduringdaytime,onceduringnighttime)butnotatthesamedistanceofagivenepicenter.Then,foreachearthquake,datahavebeencheckeduntil15daysbeforetheshockwhenthedistancebetweenthetraceoftheorbitandtheepicenterislessthan1500km.Theresultsofthestatisticalanalysisarepresentedasfunctionsofvariousparameters.Acomparisonisdonewithtwootherdatabaseswhere,ononehand,thelocationoftheepicentershasbeenrandomlymodified,andontheotherhand,thelongitudeoftheepicentershasbeenshifted.Resultsshowthatthenumberandtheintensityoftheionosphericperturbationsarelargerpriortoearthquakesthanpriortorandomevents,andthattheperturbationsincreasewiththemagnitude.

简介：

简介：

简介：AstatisticalanalysisontheWenchuanaftershockactivitytriggeredbytidalforcesissystematicallystudiedbasedonSchusterstest,includingearthquakestriggeredbytidalforce,tidalstressandtidalcoulombfailurestress.TheresultsshowthatagroupofstrongaftershockswhichoccurredattheendofJulytoearlyAugustin2008atthenorthofWenchuanwereobviouslytriggeredbyearthtide,thesameconclusionisdrawnbySchusterssmoothtestofthetidalforce,tidalstressandtidalcoulombfailurestress.Inaddition,theWenchuanaftershockactivityisobviouslytriggeredbyfortnighttide.Inthenorth,theaftershockshappenedmorefrequentlyinthefirstandlastquartersofthemoon,andinthesouth,theaftershockshappenedmorefrequentlyinthefirstandlastquartersofthemoonandduringthefullmoon.

简介：ThegoalofthisstudyistoanalyzethestatisticsofthebackscattersignalfrombovinecancellousboneusingaNakagamimodelandtoevaluatethefeasibilityofNakagami-modelparametersforcancellousbonecharacterization.Ultrasonicbackscattermeasurementswereperformedon24bovinecancellousbonespecimensinvitroandthebackscattersignalswerecompensatedforthefrequency-dependentattenuationpriortotheenvelopedetection.ThestatisticsofthebackscatterenvelopeweremodeledusingtheNakagamidistribution.Ourresultsrevealthatthebackscatterenvelopemainlyfollowedpre-Rayleighdistributions,andthedeviationsofthebackscatterenvelopefromRayleighdistributiondecreasedwithincreasingbonedensity.TheNakagamishapeparameter(i.e.,m)wassignificantlycorrelatedwithbonedensities(R=0.78–0.81,p<0.001)andtrabecularmicrostructures(|R|=0.46–0.78,p<0.05).Thescaleparameter(i.e.,?)andsignal-to-noiseratio(SNR)alsoyieldedsignificantcorrelationswithbonedensityandstructuralfeatures.Multiplelinearregressionsshowedthatbonevolumefraction(BV/TV)wasthemainpredictoroftheNakagamiparameters,andmicrostructureproducedsignificantlyindependentcontributiontothepredictionofNakagamidistributionparameters,explaininganadditional10.2%ofthevarianceatmost.TheinvitrostudyshowedthatstatisticalparametersderivedwithNakagamimodelmightbeusefulforcancellousbonecharacterization,andstatisticalanalysishaspotentialforultrasonicbackscatterboneevaluation.

简介：Ａｐｐｌｉｃａｔｉｏｎｏｆｍｅｃｈａｎｉｃａｌａｎｄｓｔａｔｉｓｔｉｃａｌｍｏｄｅｌｓｔｏｔｈｅｓｔｕｄｙｏｆｓｅｉｓｍｉｃｉｔｙｏｆｓｙｎ－ｔｈｅｔｉｃｅａｒｔｈｑｕａｋｅｓａｎｄｔｈｅｐｒｅｄｉｃｔｉｏｎｏｆｎａｔｕｒａｌｏｎｅｓＹＡＯ－ＬＩＮＳ...

简介：ThispaperconstructsasetofconfidenceregionsofparametersintermsofstatisticalcurvaturesforAR(q)nonlinearregressionmodels.Thegeometricframeworksareproposedforthemodel.Thenseveralconfidenceregionsforparametersandparametersubsetsintermsofstatisticalcurvaturesaregivenbasedonthelikelihoodratiostatisticsandscorestatistics.Severalpreviousresults,,suchas[1]and[2]areextendedtoAR(q)nonlinearregressionmodels.

简介：Inrealmultiple-inputmultiple-output(MIMO)systems,theperfectchannelstateinformation(CSI)maybecostlyorimpossibletoacquire.Butthechannelstatisticalinformationcanbeconsideredrelativelystationaryduringlong-termtransmission.Thestatisticalinformationcanbeobtainedatthereceiverandfedbacktothetransmitteranddonotrequirefrequentupdate.Byexploitingchannelmeanandcovarianceinformationatthetransmittersimultaneously,thispaperinvestigatestheoptimaltrans-missionstrategyforspatiallycorrelatedMIMOchannels.Anupperboundofergodiccapacityisderivedandtakenastheper-formancecriterion.Simulationresultsarealsogiventoshowtheperformanceimprovementoftheoptimaltransmissionstrategy.

简介：Theactivitiesofgeomagneticstormsaregenerallycontrolledbysolaractivities.Thecurrentsolarcycle(SC)24isfoundtobemild;comparedtoSCs19–23,thestormoccurrenceandsizederivedbyaveragingtheoccurrencenumberandDstaroundthesolarmaximumarereducedbyabout50–82%and36–61%,respectively.Weestimateseparately,forSC19to24,therepeatintervalsbetweengeomagneticstormsofspecificDst,basedonfitsofpower-lawandlog-normaldistributionstothestormdataforeachSC.RepeatintervalsbetweensupergeomagneticstormswithDst≤–250nTarefoundtobe0.36–2.95year(s)forSCs19–23,butabout20yearsbasedonthedataforSC24.Wealsoestimatetherepeatintervalsbetweencoronalmassejections(CMEs)ofspecificspeed(VCME)sinceCMEsareknowntobethemaindriversofintensestormsandtherelatedstatisticsmayprovideinformationaboutthepotentialoccurrenceofsupergeomagneticstormsfromthelocationoftheSun.OuranalysisfindsthataCMEwithVCME≥1860km/smayoccuronceper3and5monthsinSC23and24,respectively.BasedonaVCME-Dstrelationship,suchafastCMEmaycauseastormwithDst=–250nTifarrivingattheEarth.BycomparingtheobservedgeomagneticstormstostormsexpectedtobecausedbyCMEs,wederivetheprobabilityofCMEcausedstorms,whichisdependentonVCME.ForaCMEfasterthan1860km/s,theprobabilityofaCMEcausedstormwithDst≤–250nTisabout1/5forSC23or1/25forSC24.AlloftheaboveresultssuggestthatthelikelihoodoftheoccurrenceofsupergeomagneticstormsissignificantlyreducedinamildSC.