简介:一个网络的聚类的系数C,是在各种各样的节点的邻居之间的直接连接的一项措施,从0(为没有连接)到1(为完整的连接)。我们基于在从一个来源节点的距离h的节点定义一个小世界的网络的扩大聚类的系数C(h),因此概括distance-1邻居在计算平常的聚类系数C=C(1)采用了。在一个网络关于距离分发Pδ(h)基于已知的结果,也就是说概率顶点的随机选择的对有距离h,我们发源;试验性地验证法律Pδ(h)C(h)≤c木头N/N,在c是很少超过1的一个小常数的地方。因为它证明产品Pδ(h)C(h)由是比为Pδ(h)的最大的价值的产品更加小的价值是上面界限的,这结果是重要的;C(h)。聚类系数扩大;管理他们的法律提供新卓见进小世界的网络的结构;为他们的性质的进一步的探索开创大街。
简介:Inthispaper,anextendedmethodisproposedforconstructingnewformsofexacttravellingwavesolutionstononlinearpartialdifferentialequationsbymakingamoregeneraltransformation.Forillustration,weapplythemethodtotheasymmetricNizhnik-Novikov-VesselovequationandthecoupledDrinfel'd-Sokolov-WilsonequationandsuccessfullycoverthepreviouslyknowntravellingwavesolutionsfoundbyChen'smethod[Y.Chen,etal.Chaos,SolitonsandFractals22(2004)675;Y.Chen,etal.Int.J.Mod.Phys.C4(2004)595].
简介:Robotlocomotionisanactiveresearcharea.Inthispaperwefocusonthelocomotionofquadrupedrobots.Aneffectivewalkinggaitofquadrupedrobotsismainlyconcernedwithtwokeyaspects,namelyspeedandstability.Thelargesearchspaceofpotentialparametersettingsforlegjointsmeansthathandtuningisnotfeasibleingeneral.Asaresultwalkingparametersaretypicallydeterminedusingmachinelearningtechniques.Amajorshortcomingofusingmachinelearningtechniquesisthesignificantwearandtearofrobotssincemanyparametercombinationsneedtobeevaluatedbeforeanoptimalsolutionisfound.Thispaperproposesadirectwalkinggaitlearningapproach,whichisspecificallydesignedtoreducewearandtearofrobotmotors,jointsandotherhardware.Inessenceweprovideaneffectivelearningmechanismthatleadstoasolutioninafasterconvergencetimethanpreviousalgorithms.Theresultsdemonstratethatthenewlearningalgorithmobtainsafasterconver-gencetothebestsolutionsinashortrun.Thisapproachissignificantinobtainingfasterwalkinggaitswhichwillbeusefulforawiderangeofapplicationswherespeedandstabilityareimportant.Futureworkwillextendourmethodssothatthefasterconvergencealgorithmcanbeappliedtoatwoleggedhumanoidandleadtolesswearandtearwhilststilldevelopingafastandstablegait.
简介:Thereliabilityoftheproductsoldunderawarrantyisusuallymaintainedbythemanufacturerduringthewarrantyperiod.Aftertheexpiryofthewarranty,however,theconsumerconfrontsaproblemabouthowtomaintainthereliabilityoftheproduct.Thispaperproposes,fromtheconsumer’sperspective,areplacementpolicyaftertheextendedwarranty,undertheassumptionthattheproductissoldundertherenewablefreereplacementwarranty(RFRW)policyinwhichthereplacementisdependentontherepair-costthreshold.Theproposedreplacementpolicyisthereplacementaftertheextendedwarrantyisperformedbytheconsumerbasedontherepair-costthresholdorpreventivereplacement(PR)age,whicharedecisionvariables.Theexpectedcostratemodelisderivedfromtheconsumer’sperspective.Theexistenceanduniquenessoftheoptimalsolutionthatminimizestheexpectedcostrateperunittimeareoffered.Finally,anumericalexampleispresentedtoexemplifytheproposedmodel.
简介:Thesurface-relatedmultipleelimination(SRME)methodisbasedonfeedbackformulationandhasbecomeoneofthemostpreferredmultiplesuppressionmethodsused.However,somedifferencesareapparentbetweenthepredictedmultiplesandthoseinthesourceseismicrecords,whichmayresultinconventionaladaptivemultiplesubtractionmethodsbeingbarelyabletoeffectivelysuppressmultiplesinactualproduction.ThispaperintroducesacombinedadaptivemultipleattenuationmethodbasedontheoptimizedeventtracingtechniqueandextendedWienerfiltering.ThemethodfirstlyusesmultiplerecordspredictedbySRMEtogenerateamultiplevelocityspectrum,thenseparatestheoriginalrecordtoanapproximateprimaryrecordandanapproximatemultiplerecordbyapplyingtheoptimizedeventtracingmethodandshort-timewindowFKfilteringmethod.AfterapplyingtheextendedWienerfilteringmethod,residualmultiplesintheapproximateprimaryrecordcanthenbeeliminatedandthedamagedprimarycanberestoredfromtheapproximatemultiplerecord.ThismethodcombinestheadvantagesofmultipleeliminationbasedontheoptimizedeventtracingmethodandtheextendedWienerfilteringtechnique.Itisanidealmethodforsuppressingtypicalhyperbolicandothertypesofmultiples,withtheadvantageofminimizingdamageoftheprimary.Syntheticandfielddatatestsshowthatthismethodproducesbettermultipleeliminationresultsthanthetraditionalmulti-channelWienerfiltermethodandismoresuitableformultipleeliminationincomplicatedgeologicalareas.
简介:ThemetalbindingsitesinthetwoPtcontainingmetallothioneins(Pt-MTandPt14MT)wereexaminedbymeansofPt(II)L3-edgeextendedX-rayabsorptionrinestructure(EXAFS)spectroscopy.ComparisonsbetweenthephaseandamplitudefunctionsderivedfromtheisolatedshellstothoseofPt…Pt.Pt-SandPt-NmodelcomponentsshowedthateachplatinuminPt7MTwascoordinatedbyfoursulfuratomsatadistanceof2.31±0.01A.AnalysisoftheoutershelldataofplatinumatominPt7MTindicatedbackscatteringplatinumatomatapproximate4.29A.StrkinglydifferentstructuralparametershadbeenobtainedforthePt14MTspecies.fittingofthefirstshellrevealedthateachplatinumwascoordinatedbytwosulfursatthedistanceof2.3-±0.02Aandtwonitrogensat2.02±0.02A.TheresultsoftheworkprovidedthedetailedinformationconcerningthelocalenvironmentsofthecoordinatedPt(II)inthesetwoplatinothioneins.
简介:在这篇论文,我们扩大印射的途径到N顺序Schroedingerequation。以扩大印射的途径,有一些任意的函数的可变分离解决方案的新家庭被导出。
简介:Toinvestigatetheprevalenceandgenotypeofextendedspectrumbeta-lactamases(ESBLs)mediatedbyplasmidinGram-negativebacteriafoundinsouthernChina,atotalof1184clinicalisolatesofnon-repetitivestrainsofGram-negativebacteriawerecollectedin2001from5differentcitiesinsouthernChina.TheESBLs-producingisolatesweredistinguishedbymeansofthephenotypeconfimatorytestbasedontheNCCLScriteriaandweresubjectedtoplasmidconjugationandelectroporationexperiments.Thoseclinicalisolatessucceededinplasmidtransfershadundergoneplasmidconjugationandelectro-transformation,plasmidDNAextractionandPstⅠdigestlinger-printinganalysis,aswellasthetmiversalprimerPCRamplificationoftheTEM,SHV,CTX-M,VEB,PERandSFOgenesandtheDNAsequencinginordertodeterminethegenotypesofESBLsandtheirplasmidlocations.ItwasfoundthattheincidenceoftheESBLs-producingstrainsofGram-negativebacteriawas14.6%(173/1184)with67strainsoftransconjugantsand11strainsofelectro-transformants,inwhichCTX-M-14typewas33.3%(26/78);CTX-M-3typewas23.1%(18/78);CTX-M-9typewas14.1%(11/78);CTX-M-5typewas6.4%(5/78);CTX-M-13typewas2.6%(2/78);SHV-5typewas7.7%(6/78);SHV-12typewas5.1%(4/78),SHV-2atypewas2.6%(2/78)andunidentifiedtypewas5.1%(4/78).29.5%ofthewildstrainsalsocarriedbroad-spectrumbeta-lactamasesTEM-1andSHV-1types.TheabovementionedESBLsgeneswerelocatedontransferableplasmidswithvariablesizes(from35to190kb).TheCTX-MtypeESBLswascharacterizedbyhigh-levelofresistancetocefotaxime.ItconcludedthattheCTX-M-typewasthemostprevalentgenotypeinclinicalisolatesofGram-negativebacteriainsouthernChina,andtheSHVtyperanksinthesecondplace.TEM-,VEB-,Toho-andPER-typeswerenotfoundintheseisolates.
简介:AbstractObjective:To describe and assess the repair technique and perioperative management for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture via extradural anterior skull base approach.Methods:This was a retrospective review conducted at the Department of Neurosurgery of the Shanghai Tenth People's Hospital from January 2015 to April 2020. Patients with traumatic CSF rhinorrhea resulting from extensive anterior skull base fracture treated surgically via extended extradural anterior skull base approach were included in this study. The data of medical and radiological records, surgical approaches, repair techniques, peritoperative management, surgical outcome and postoperative follow-up were analyzed. Surgical repair techniques were tailored to the condition of associated injuries of the scalp, bony and dura injuries and associated intracranial lesions. Patients were followed up for the outcome of CSF leak and surgical complications. Data were presented as frequency and percent.Results:Thirty-five patients were included in this series. The patients’ mean age was 33 years (range 11-71 years). Eight patients were treated surgically within 2 weeks; while the other 27 patients, with prolonged or recurrent CSF rhinorrhea, received the repair surgery at 17 days to 10 years after the initial trauma. The mean overall length of follow-up was 23 months (range 3-65 months). All the patients suffered from frontobasal multiple fractures. The basic repair tenet was to achieve watertight seal of the dura. The frontal pericranial flap alone was used in 20 patients, combined with temporalis muscle and/or its facia in 10 patients. Free fascia lata graft was used instead in the rest 5 patients. No CSF leak was found in all the patients at discharge. There was no surgical mortality in this series. Bilateral anosmia was the most common complication. At follow-up, no recurrent CSF leak or meningitis occurred. No patients developed mucoceles, epidural abscess or osteomyelitis. One patient ultimately required ventriculoperitoneal shunt because of progressive hydrocephalus.Conclusion:Traumatic CSF rhinorrhea associated with extensive anterior skull base fractures often requires aggressive treatment via extended intracranial extradural approach. Vascularized tissue flaps are ideal grafts for cranial base reconstruction, either alone or in combination with temporalis muscle and its fascia—fascia lata sometimes can be opted as free autologous graft. The approach is usually reserved for patients with traumatic CSF rhinorrhea in complex frontobasal injuries.
简介:Basedontheextendedmappingdeformationmethodandsymboliccomputation,manyexacttravellingwavesolutionsarefoundforthe(3+1)-dimensionalJMequationandthe(3+1)-dimensionalKPequation.Theobtainedsolutionsincludesolitarysolution,periodicwavesolution,rationaltravellingwavesolution,andJacobianandWeierstrassfunctionsolution,etc.
简介:在这份报纸,有效模型结构一个秒顺序抵抗电容网络和简单地分析的开的电路电压对充电(SOC)的状态创作了地图被使用为电的车辆(EV)描绘一节锂铁磷酸盐电池的电压行为。作为结果,电池的过电位能用一个秒顺序电路网络被描绘,模型parameterization能在装载侧面的任何电池下面被认识到,没有一个特殊描述实验。以便保证好坚韧性,过滤的扩大Kalman被采用递归地实现刻度过程。涉及刻度算法的linearization在一种递归的形式通过周期性的衍生物被认识到。递归地校准的电池模型能精确地描出的确认结果表演在二不同短暂力量操作下面的电池电压行为调节。当SOC是相对低的时,与一个一阶的模型一起的比较显示递归地校准的秒顺序模型在电池SOC范围和更好的表演的主要部分有可比较的精确性。
简介:Amodel-basedestimatordesignandimplementationisdescribedinthispapertoundertakecombinedestimationofvehiclestatesandtire-roadfrictioncoefficients.Theestimatorisdesignedbasedonavehiclemodelwiththreedegreesoffreedom(3-DOF)andthedualextendedKalmanfilter(DEKF)techniqueisemployed.EffectivenessoftheestimationisexaminedandvalidatedbycomparingtheoutputsoftheestimatorwiththeresponsesofthevehiclemodelinCarSiminthreetypicalroadadhesionconditions(high-friction,low-friction,andjoint-frictionroads).SimulationresultsdemonstratethattheDEKFestimatoralgorithmdesignedisabletoobtainvehiclestates(e.g.,yawrateandrollangle)aswellasroadfrictioncoefficientswithreasonableaccuracy.
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简介:Thereliabilityofreal-timeembeddedsoftwaredirectlydeterminesthereliabilityofthewholereal-timeembeddedsystem,andtheeffectivesoftwaretestingisanimportantwaytoensuresoftwarequalityandreliability.Basedontheanalysisofthecharacteristicsofreal-timeembeddedsoftware,theformalmethodisintroducedintothereal-timeembeddedsoftwaretestingfieldandthereal-timeextendedfinitestatemachine(RT-EFSM)modelisstudiedfirstly.Then,thetimezonedivisionmethodofreal-timeembeddedsystemispresentedandthedefinitionanddescriptionmethodsoftime-constrainedtransitionequivalenceclass(timeCTEC)arepresented.Furthermore,theapproachesofthetestingsequenceandtestcasegenerationareputforward.Finally,theproposedmethodisappliedtoatypicalavionicsrealtimeembeddedsoftwaretestingpracticeandtheexamplesofthetimeCTEC,testingsequencesandtestcasesaregiven.Withtheanalysisofthetestingresult,theapplicationverificationshowsthattheproposedmethodcaneffectivelydescribethereal-timeembeddedsoftwarestatetransitioncharacteristicsandreal-timerequirementsandplaytheadvantagesoftheformalmethodsinaccuracy,effectivenessandtheautomationsupporting.Combinedwiththetestingplatform,thereal-time,closedloopandautomatedsimulationtestingforreal-timeembeddedsoftwarecanberealizedeffectively.