简介:有部分微分方程的优化问题在科学和工程的许多区域广泛地作为限制产生,特别地处于设计的问题。抑制PDE的优化问题的如此的类的解决方案通常是一项主要计算任务。因为为直接寻求抑制PDE的优化问题的答案的肤色,我们由使用Galerkin把它转变成僵绳点形式的线性方程的一个系统有限元素的discretization。为discretized线性系统,在这份报纸,我们构造一块对称并且block-lower-triangularpreconditioner,为解决抑制PDE的优化问题。两preconditioners利用系数矩阵的结构。为相应preconditioned矩阵的特征值和特徵向量的明确的表情被导出。当规则化参数是合适小的时,数字实现证明这些块preconditioners能为preconditionedGMRES方法导致令人满意的试验性的结果。[从作者抽象]
简介:Anewblock-basedfractalimagecodingalgorithmcalledFractalBlockCodinginResidueDomain(FBCRD)isproposed.InbasicFractalBlockCoding(FBC)algorithm,eachblock(calledrangeblock)isencodedbyanaffinemappingfromadomainblockwithinthesameimagetoitself.Thedecoderusestheparametersofthesemappingstosynthesizethereconstructedimagethroughaniterativeprocedure.FBCRDisamodificationofbasicFBC.InFBCRD,rangeblocksanddomainblocksareallresidueblockssubtractedfromtheirblockmeansandboththeparametersofaffinemappingsandblockmeansarecoded.Thismodificationleadstofeweriterationsatthedecoder.AnoptimizeddecodingstrategyisalsointroducedwhichreducestotaldecodingtimebymorethanhalfofthatofbasicFBC.Thisimprovementisfavorableforrealtimeimplementationoffractalimagecompression.
简介:Trellisstructuresofblockcodesarediscussed.L-sectiontrellisstructuresofsomeBCHcodesarepresented.AfastmaximumlikelihooddecodingalgorithmforBCHcodesisproposedcorrespondingly,thedecodingproblemofq-aryimagesofqm-aryblockcodesisalsodiscussed.Thedirect-sumpartitionandtheassociateddecodingalgorithmsaregivenfortheimages.
简介:ThisstudyfocusesonthebasementstructureoftheParanáBasininSouthAmerica,basedongeologicalandgeophysicaldata.ItisalargeintracratonicbasinformedfromtheLateOrdovicianuntiltheCretaceous,whenasequenceofcontinentalfloodbasaltseruptionscoveredtheentirebasin,precedingthebreak-upofWesternGondwana.Isostaticmodelingwasappliedtolargegravitysurveyscomprisingmorethan12,000gravitystations.TheresidualBougueranomalypattern,representingthecrustalcontributionofthecrystallinebasement,aswellasthesedimentaryandvolcaniclayersofthebasin,revealssimilaritiesbetweenthebasementgravitysignatureandtheexposedrock.ThestresspatternsoftheLateOrdovicianandCretaceoustectoniceventspresentageographicallycoincidentmaximum,andthecorrelationbetweengravityhighsandthemainattenuation(betafactor)suggeststhepresenceofsomepreexistentsuturezones.TheresultantmosaicofgravityblocksandthelocationofmajorfaultsgivesupporttothepresenceofanimportantProterozoiccratonicfeature,herereferredtoasParanapanemablock.
简介:1IntroductionandPreliminariesItiswellknownthatthesmallestsingularvalueofamatrixisimportantinmatrixthoeryandapplications.VarahandQi,Johnsongavesomeresultsonlowerboundofthesmallestsingularvalue[1—4].Here,weusetheblockpartitionedformofamatrixtoob-taingeneralizedlowerboundsforσn(A).Furthermore,byscalingwithamatrixDweob-tainanewlowerboundforσAofmatriceswhicharenotpositivedefinitematrices.
简介:Inthispaper,theL^2-boundednessofaclassofparametricMarcinkiewiczintegralμa,h^pwithkernelfunctionΩinBq^0.0(s^n-1)forsomeq>1,andtheradialfunctionh(x)∈l∞(L^s)(R+)for1
简介:Basedonelementarygrouptheory,theblockpivotmethodsforsolv-ingtwo-dimensionalelasticfrictionalcontactproblemsarepresentedinthispaper.Itisprovedthatthealgorithmsconvergewithinafinitenumberofstepswhenthefrictioncoefficientis'relativesmall'.Unlikemostmathematicalprogrammingmeth-odsforcontactproblems,theblockpivotmethodspermitmultipleexchangesofbasicandnonbasicvariables.
简介:WepresentsomerepresentationsforthegeneralizedDrazininverseofablockmatrixx=[abcd]inaBanachalgebraAintermsofa~dand(bc)~dundercertainconditions,extendingsomerecentresultrelatedtothegeneralizedDrazininverseofananti-triangularoperatormatrix.Also,severalparticularcasesofthisresultareconsidered.
简介:Thesymmetriclinearsystemgivesusmanysimplificationsandapossibilitytoadaptthecomputationstothecomputerathandinordertoachievebetterperformance.TheaimofthispaperistoconsidertheblockbidiagonalizationmethodsderivedfromasymmetricaugmentedmultiplelinearsystemsandmakeacomparisonwiththeblockGMRESandblockbiconjugategradientmethods.