简介:Theinstabilityofboreholewallisalwaysadifficultquestionindrillingboreholeprogress.Itincreasesthecostofproductionandprolongsproductioncycle.Soithasasignificantresearchvalue.Consideringtheeffectofmudpressureandporepressureonthestabilityofboreholewall,thispaperestablishesamathmodelbyapplyingthetwo-dimensionalbondtheoryofBiot.Itappliesthemethodofthenumericalsimulationtoanalyzetheeffectofmudpressureandporepressureonthestabilityofboreholewall.Thesimulationresultsshowthatthemudpressureimposesgreatinfluenceonstressfieldandonthedeformationofboreholesoil,whichprovidesatheoreticalbasisduringthedrillingprocesstoavoidtheinstabilityoftheboreholeandtostudyhowtoselectreasonablemudandmudpressure.
简介:TheimplementationofJapanesepost-warpoliciestowardsChinahasbeenthroughagraduallyshiftingprocess,chronologicallygoingfrompoliciesofanti-Chinasentiment,friendlycooperationandacombinationofcautionandcooperation.UnderthecontextoftheseadjustingpoliciestowardsChina,thenationalpoliticalenvironmentandtheAmericanpowerofdiscoursehavebothsignificantlyaffectedJapaneseauthorities.Atthesametime,commoneconomicinterestandcautionconcerningChina’scompetitivenesshavealwaysbeenastableconsideration.
简介:Inthispaper,usingcapacitytheoryandextensiontheoremofLipschitzfunctionswefirstdiscusstheuniquenessofweaksolutionofnonhomogeneousquasilinearellipticequationsinspaceW(θ,p)(Ω),whichisbiggerthanW1,p(Ω).Next,usingrevisereverseHolderinequalityweprovethatifωcisuniformlyp-think,thenthereexistsaneighborhoodUofp,suchthatforallt∈U,theweaksolutionsofequationcorrespondingtareboundeduniformly.Finally,wegetthestabilityofweaksolutionsonexponentp.
简介:Thecompletesolutionsoftheuprightandobliquepermanentrotationsofasymmetricheavygyroscopewithperfectdissipationaregiven.TheasymptoticstabilitycriteriaandunstabilitycriteriafortheserotationsinthesenseofLiapunovandthesenseofMovchanarealsogivenonthebasisofexactnonlinearmotionequationsrespectively.Therelatedobliquerotationsarenon-isolated.Themainsubdomainsofthere-gionsofasymptoticstabilityareobtained.Therelatedbifurcationphenomenaarediscussedindetail.
简介:Thispaperpresentsthestabilityofdifferenceapproximationsofanoptimalcontrolproblemforaquasilinearparabolicequationwithcontrolsinthecoefficients,boundaryconditionsandadditionalrestrictions.Theoptimalcontrolproblemhasbeenconveredtooneoftheoptimizationproblemusingapenaltyfunctiontechnique.Thedifferenceapproximationsproblemfortheconsideredproblemisobtained.Theestimationsofstabilityofthesolutionofdifferenceapproximationsproblemareproved.Thestabilityestimationofthesolutionofdifferenceapproximationsproblembythecontrolsisobtained.
简介:Usingtime-dependentcompressiblelaminarNavier-Stokesequationswithafinitevolumemethodincorporatingathird-order-accuratediscretizationscheme,theflowstructuresaroundaslenderatcertainincidencesarenumericalsimulatedandtypicalcrossflowpatternsarepresented.Atincidence10°,thesevorticalconfigurationsaredifferentatdissimilaraxiallocationsthoughtheyaresymmetric.At35°,thesymmetricvorticalstructuresstillmaintainovertheslender,yettheirinteractionatafterbodyisintensethanthatattheforebodysincethetwovorticeshavefullydevelopeddownstream.Theunstabletopologicalstructureoftrajectoryofsaddle-to-saddlepointsandmultiplelimitcyclearefurtherdiscussedintopologicalstabilitytheory.Thesestructureseasilyproducebifurcationwithperturbation.Theresultssupporttheviewofhydrodynamicinstabilityofvorticesflowfield.
简介:Thispaperdealswiththenumericalsolutionofinitialvalueproblemsforpantographdifferentialequationswithvariabledelays.Weinvestigatethestabilityofonelegθ-methodsinthenumericalsolutionoftheseproblems.Sufficientconditionsfortheasymptoticstabilityofθ-methodsaregivenbyFourieranalysisandErgodictheory.
简介:自从环境能力并且象陆地实际上联系了的居民一样可耕全部的平衡,斜坡为各种各样的工程构造正在成为越来越重要的选择。因为斜坡的地质的复杂性,设计和基于斜坡的设计的决策仍然不是实际的完全依靠理论分析和数字计算,但是主要在专家的经验上。因此,它有重要实际意义把一些成功的经验变成数学方程。在在云南设计构造盒子的丰富的典型斜坡之上基于,西南的中国,为分析斜坡稳定性的3个方法在这篇论文被开发了。首先,为分析斜坡稳定性的通信类似的数学方程通过案例研究被建立了。然后,当7个主要影响因素被采用时,人工的神经网络和multivariate回归分析也被建立了。
简介:CellularNeuralNetworks(CNN)withfeedbackmodeandM×Ncellsareequivalenttoanetworkwhichpossesses2M×Ncells,aneighborhoodwithmirror-likestructure,space-varianttemplatesandwithoutfeedbackaswellaswithoutinputtemplates.ThestabilityoftheCNNwithfeedbackmodeandtransformationswiththeneighborhoodofmirror-likestructurearediscussed.
简介:Anewmethodforanalyzingdynamicsofcontinuousneuralnetworksisproposed,andthenecessaryconvergenceconditionsforaclassofassociativenetworksareobtained.Basedonthestabilitycriterionandtheequationsofequilibriumsetofthenetwork,synthesisofaclassofassociativeneuralnetworksisgiven.Thestabilitycontrolmodelofasymmetricunstablenetworksissuggested,whichisalsoavalidwayforoptimizationanddynamiccontrolofstableneuralnetworks.