简介：Basedonthestrongearthquakecatalogue,thispaperdiscussesthecharacteristicsofthetimeseriesofstrongearthquakeactivitiesintheworld,westernChinesemainlandanditsperipheral"bigtriangleseismicregion",aswellastheChinesemainland.AccordingtotheanalysisoftheperiodicfeaturesofglobalseismicityofM≥8.0strongevents,itisfoundthatthereissignificantdifferenceinglobalseismicitybeforeandafterthe1960s.StatisticalanalysiswiththeFishermethodhasrevealedthatthe"bigtriangularseismicregion"hasexperiencedaprocessofM8.0earthquakeactivitywithadurationofoverahundredyearssince1800.Furtheranalysisshowsthattheglobalseismicityandthe"bigtriangularseismicregion"possiblyhasaperiodofahundred-yearscale,andhasquasisynchronicitytoacertainextent.TheshallowearthquakeactivityofMS≥7.0intheChinesemainlandisobviouslycontrolledbytheseismicityinthebigtriangularseismicregionandbyglobalseismicityinalargerspatial-scale.Intermsofthetimeseriesoftheseearthquakes,theseismicityshowsadecadalandcentury-scaleactivitypatterns.

简介：Anovelstructuraldamagedetectionmethodwithanewdamageindex,i.e.,thestatisticalmoment-baseddamagedetection(SMBDD)methodinthefrequencydomain,hasbeenrecentlyproposed.TheaimofthisstudyistoextendtheSMBDDmethodinthefrequencydomaintothetimedomainforbuildingstructuressubjectedtonon-Gaussianandnon-stationaryexcitations.TheapplicabilityandeffectivenessoftheSMBDDmethodinthetimedomainisverifiedbothnumericallyandexperimentally.Shearbuildingswithvariousdamagescenariosarefirstnumericallyinvestigatedinthetimedomaintakingintoaccounttheeffectofmeasurementnoise.Theapplicabilityoftheproposedmethodinthetimedomaintobuildingstructuressubjectedtonon-Gaussianandnon-stationaryexcitationsisthenexperimentallyinvestigatedthroughaseriesofshakingtabletests,inwhichtwothree-storyshearbuildingmodelswithfourdamagescenariosaretested.Theidentifieddamagelocationsandseveritiesarethencomparedwiththepresetvalues.Thecomparativeresultsarefoundtobesatisfactory,andtheSMBDDmethodisshowntobefeasibleandeffectiveforbuildingstructuressubjectedtonon-Gaussianandnon-stationaryexcitations.

简介：Recentadvancesincommodityhigh-performancecomputingtechnologyhavedramaticallyreducedthecomputationalcostforsolvingtheseismicwaveequationincomplexearthstructuremodels.Asaconsequence,wave-equation-basedseismictomographytechniquesarebeingactivelydevelopedandgraduallyadoptedinroutinesubsurfaceseismicimagingpractices.Wave-equationtravel-timetomographyisaseismictomographytechniquethatinvertscross-correlationtravel-timemisfitsusingfullwaveFre′chetkernelscomputedbysolvingthewaveequation.Thistechniquecanbeimplementedveryefficientlyusingtheadjointmethod,inwhichthemisfitsareback-propagatedfromthereceivers(i.e.,seismometers)toproducetheadjointwave-fieldandtheinteractionbetweentheadjointwave-fieldandtheforwardwave-fieldfromtheseismicsourcegivesthegradientoftheobjectivefunction.Oncethegradientisavailable,agradient-basedoptimizationalgorithmcanthenbeadoptedtoproduceanoptimalearthstructuremodelthatminimizestheobjectivefunction.Thismethodologyisconceptuallystraightforward,butitsimplementationinpracticalsituationsishighlycomplex,error-proneandcomputationallydemanding.Inthisstudy,wedemonstratethefeasibilityofautomatingwave-equationtravel-timetomographybasedontheadjointmethodusingKepler,anopen-sourcesoftwarepackagefordesigning,managingandexecutingscientificworkflows.Theworkflowtechnologyallowsustoabstractawaymuchofthecomplexityinvolvedintheimplementationinamannerthatisbothrobustandscalable.Ourautomatedadjointwave-equationtravel-timetomographypackagehasbeensuccessfullyappliedonarealactive-sourceseismicdataset.

简介：structure-foundation-soil的考虑动态相互作用是在原子力量设备的地震安全的评估的一个基本要求。一个有效、精确的动态相互作用在时间领域的数字模型成为了当前的研究的一个重要话题。在这研究，放大边界有限元素方法(SBFEM)与好申请前景用作一条有效数字途径被改进。这个方法有几个优点，包括维数减小，光线的分析答案的精确性，和不同其它边界元素方法，它不要求一个基本答案。这研究集中于证实高效放大了边界在时间领域的有限元素相互作用分析模型基于加速单位推动反应矩阵，在哪个几种新溶液技术，例如一个无尺寸的方法到解决相互作用力量，被使用改进实际土壤参数的数字稳定性并且减少计算的数量。最后，领域方法被原子力量结构和算法的精确性的反应说明的时间的可行性被比较动态地与一个大规模粘弹性的土壤模型的精炼验证。

简介：为了有效地总共最小化电磁的地反应，回答答案，我们建议一个数字建模方法为二维(2D)timedomain线来源的短暂的电磁的第二等的地基于DuFort-Frankel有限差别的方法。在建议方法，我们包括了地球空气边界传导性的处理，计算了导致的起电的力量(Emf)的规范的部分衍生物，并且决定了前面的时间步。由向上扩大地球空气连接到空气格子节点和零值的边界条件，不是仅仅，我们有比全部的域解决方案更有效而且简单的一个方法。我们与高precisionthe最大值亲戚错误计算了并且分析同类的一半空间模型和完全分层的模型在我们的方法和答案速度是的分析methodand之间是不到0.01%粗略地，三比全部地的答案快预定。最后，我们使用了在不同延期时间在同类的一半空间嵌入描绘导致的旋涡水流，和在电磁的地之间的物理相互作用过程的向下并且向上传播的特征的薄身体和地下的低抵抗力的身体的模型。

简介：Inthispaper,theforecastingequationsofa2nd-orderspace-timedifferentialremainderarededucedfromtheNavier-StokesprimitiveequationsandEulerianoperatorbyTaylor-seriesexpansion.Hereweintroduceacubicsplinenumericalmodel(SplineModelforshort),whichiswithaquasi-Lagrangiantime-splitintegrationschemeoffittingcubicspline/bicubicsurfacetoallphysicalvariablefieldsintheatmosphericequationsonsphericaldiscretelatitude-longitudemesh.Anewalgorithmof'fittingcubicspline—timestepintegration—fittingcubicspline—……'isdevelopedtodeterminetheirfirst-and2nd-orderderivativesandtheirupstreampointsfortimediscreteintegraltothegoverningequationsinSplineModel.AndthecubicsplinefunctionanditsmathematicalpolaritiesarealsodiscussedtounderstandtheSplineModel’smathematicalfoundationofnumericalanalysis.ItispointedoutthattheSplineModelhasmathematicallawsof'convergence'ofthecubicsplinefunctionscontractingtotheoriginalfunctionsaswellasits1st-orderand2nd-orderderivatives.The'optimality'ofthe2nd-orderderivativeofthecubicsplinefunctionsisoptimalapproximationtothatoftheoriginalfunctions.Inaddition,aHermitebicubicpatchisequivalenttooperateonagridfora2nd-orderderivativevariablefield.Besides,theslopesandcurvaturesofacentraldifferenceareidentifiedrespectively,withasmoothingcoefficientof1/3,three-pointsmoothingofthatofacubicspline.Thentheslopesandcurvaturesofacentraldifferencearecalculatedfromthesmoothingcoefficient1/3andthree-pointsmoothingofthatofacubicspline,respectively.Furthermore,aglobalsimulationcaseofadiabatic,non-frictionaland'incompressible'modelatmosphereisshownwiththequasi-LagrangiantimeintegrationbyusingaglobalSplineModel,whoseinitialconditioncomesfromtheNCEPreanalysisdata,alongwithquasi-uniformlatitude-longitudegridsandtheso-called'shallowatmosphere'Navier-Stokesprimitiveequationsinthes