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1.
IntroductionConsidertheswitchedlinearsystemwithmultipletime_delaysincontrolfunctiongivenby x(t) =Ar(t) x(t) +Br(t) u(t) + Kk=1Dr(t) ,ku(t -τk) ,(1)wherex(t) ,u(t)andr(t)isdefinedasbefore ,(Ai,Bi,Di,1,… ,Di,K)|i=1,… ,Nisafinitefamilyofsystemrealizations.Moreover,r(t) =iimplies (Ai,Bi,Di,1,… ,Di,K)ischosenasthesystemrealizationattimet.K <∞isthenumberoftime_delaysinthesystem .0<τ1<… <τKareKfixedtime_delays .Remark 1 Similarly ,wecandescribeswitchingpathbyintroducingswitchingsequ…  相似文献   

2.
IntroductionWeconsiderthefollowingnonlinearBurgers’equation : u t u u x=ε 2 u x2 ,   0 0 ,( 1 )withtheinitialandtheboundaryconditions     u(x,0 ) =f(x) ,   0 相似文献   

3.
IntroductionInthispaper,anasymptotictheoryisestablishedforthefollowinginitialvalueproblemforasemilinearperturbedwaveequation :utt-Δu=εf(u ,ε)   (t>0 ,x∈R2 ) ,(1 )u(0 ,x,ε) =u0 (x ,ε)   (x∈R2 ) ,(2 )ut(0 ,x,ε) =u1(x ,ε)   (x∈R2 ) ,(3 )where  相似文献   

4.
ntroductionLetΩ R2 beaboundeddomain .Weconsiderthefollowingnon_stationarynaturalconvectionproblem :Problem (Ⅰ ) Findu =(u1,u2 ) ,p ,andTsuchthat,foranyt1>0 ,ut- μΔu +(u· )u + p=λjT   ((x ,y ,t) ∈Ω× (0 ,t1) ) ,divu =0          ((x ,y,t) ∈Ω× (0 ,t1) ) ,Tt-ΔT +λu· T =0   ((x,y,t) ∈Ω× (0 ,t1) ) ,u =0 ,T =0       ((x,y,t)∈ Ω× (0 ,t1) ) ,u(x ,y ,0 ) =0 , T(x,y,0 ) =f(x,y)   ((x,y) ∈Ω) ,whereuisthefluidvelocityvectorfield ,pthepressurefield ,Tthet…  相似文献   

5.
IntroductionInthispaper,westudyT_periodicsolutionsofthefollowingnonlinearsystemwithmultipledelays x(t) =f(t,x(t) ,x(t-τ1(t) ) ,… ,x(t -τm(t) ) ) ,(1 )wherex(t) ∈C(R ,R) ,fiscontinuous,f(t+T ,·) =f(t,·) ,τi(t) (i=1 ,2 ,… ,m)arecontinuousperiodicfunctionsofperiodT .AlemmaisintroducedfordiscussingtheexistenceofT_periodicsolutionofsystem (1 ) .LetXbeaBanachSpace ,considerthefollowingoperatorequation :Lx =λNx   (λ∈ [0 ,1 ] ) ,whereL :DomL∩X→Xisalinearoperator,λ∈ [0 ,1 ]isapa…  相似文献   

6.
IntroductionThe following coupled cubic nonlinear Schr dinger equations inR2are considered:it-Δ=(||2-|ψ|2),t>0,x∈R2,iψt-Δψ=(-||2 |ψ|2)ψ,t>0,x∈R2,(1)where=(t,x):[0,T)×R2→C,ψ=ψ(t,x):[0,T)×R2→C,Δis the Laplaceoperator onR2.The e  相似文献   

7.
Introduction InthispaperasymptotictheoryofthefollowinginitialvalueproblemforanonlinearKlein Gordonequationisconsidered.tt-Δ =εF(t,x,,ε),t>0,x∈R2,(0,x,ε)=0(x,ε),t(0,x,ε)=1(x,ε),x∈R2,(1)where(t,x)isarealvaluedunknownfunction,Δ=2i  相似文献   

8.
1ConvexProgrammingandExactPenaltyFunction Weconsiderthefollowingconvexprogramming:(P)minf(x)s.t.x∈S={x∈Rn:gi(x)≤0,i=1,…,m}.SupposethatSisacompactset.ThusthereexistsalargeboundedboxX,suchthatS={x∈Rn:gi(x)≤0,i=1,…,m}intX.Assumethatf(x),gi(x),i=1,…,m  相似文献   

9.
IntroductionAsymmetricregularizedlongwaveequation (SRLWE) 2 x2 -1 u t = x ρ+ 12 u2 ,  ρ t+ u x=0 (1 )hasbeeninvestigatedinRef.[1 ] .Thesystem (1 )ofequationsisshowntodescribeweaklynonlinearion_acousticwaveandspace_chargewaves.Thehuperbolicsecantsquaredsolitarywaves ,thefourconservationlaws,andsomenumericalresultshavebeenobtainedinRef.[1 ] .Obviously ,eliminatingρin (1 ) ,weobtainaclassofregularizedlongwaveequationutt-uxx+ 12 u2xt-uxxtt =0 . (2 )TheSRLWequationisexplicitlysymmetric…  相似文献   

10.
I.IntroductionConsiderthefollowingsemilinearperturbedtelegraphequationuII-u., P'u==sj(t,x,u,ul,u,,e)(-ooo)(l.l)u(o,x)=u,(x,e)(-ooo,u=u(t,x),fuoandulsatisfycertainsmoo…  相似文献   

11.
IntroductionLetf(x ,λ)beagivenpowerserieswithfunction_valuedcoefficients,i.e.,f(x ,λ) =c0 (x) +c1(x)λ+c2 (x)λ2 +… +cn(x)λn+… ,( 1 )wherecj(x)isarealorcomplexfunctionwithregardasxwhichisdefinedon (a ,b) .Supposethatf(x,λ)isanalyticasafunctionofλattheoriginλ=0 .ItisknownthatPad啨approximantmethodsareusedforobtainingthesolutionofawkwardintegralequations,andespeciallythosewhichpossessageneratingfunctionoftheform ( …  相似文献   

12.
IntroductionForthestudyofwellposednessontheinitialorboundaryproblemsabouttheEulerequations,therearemanyimportantresultsgivenbydifferentmethodsindifferentfunctionclasses[1]- [4 ].Thepaper (Ⅰ )oftheauthordiscussedtheill_posednessoftheCauchyproblemswhichsatisfythesameconditionsoftheinitialvalueproblematthehypersurfacet=t( 0 ) +g(x) ,g(x) ≠constant,g(0 ) =0 R4,andgavetwodifferentformalsolutions[5 ].Italsogavetheformulasforcomputation .Inthepresentpaper,twokindsofillposednessoftheEulerequation…  相似文献   

13.
1 IntroductionandProblemWeshallstudytheoptimalcontrolproblemsgovernedbynonlinearparabolicvariationalinequalitiesoftheformy′+Ay +β(y) ∈Bu+f(a.e .(x,t)∈Q =Ω× [0 ,t]) ,y(0 ) =y0 , ( )withthestateconstraintF(y) S ,andthecostfunctionalI(y,u) .Whereβisadiscontinuous,nonlinearandnonmonotonemulti_valuedmapping .Theoptimalcontrolproblemsofthedifferentialsystemshavebeenstudiedforalongtime.Manyscholars,suchasJ.L .Lions ,V .Barbu ,D .Tiba,andF .Mignotetal.,haveresearchedtheoptimalcontrolpr…  相似文献   

14.
IntroductionIt’swell_knownthatthecomplicatedfundamentalsolution[1,2 ]forHelmholtzequationΔu(x) +k2 u(x) =0  (x∈Ω:boundedopenregioninR2 )isu (x,y) =-iH(2 )0 (k x-y ) 4,thusit’snotconvenientfornumericalcomputation .IfapplyingthesimplefundamentalsolutionofLaplaceequationu 0 (x ,y) =-ln|x-y|(2π) ,theexpressionforthesolutionofequationintheclosedregion Ωisc(y)u(y) + ∫Γu(x) u 0 (x,y) nx -u 0 (x ,y) u(x) n dsx =-k2∫Ωu(x)u 0 (x,y)dΩx.Astherightsideappearstheregionalintegrationinclu…  相似文献   

15.
In this paper we are interested in the large time behavior of the nonlinear diffusionequationu_1=(φ(u))_xx φ(u), x∈R,t∈R~ =(0, ∞))We consider functionsφ(u)andφ(u)which allow the equation to possess travelingwave solutions.We first present an existence and uniqueness as well as some comparisonprinciple result of generalized solutions to the Cauchy problem.Then we give forφ(u)=u(1-u)(u-a)some threshold results,from which we can see that u=a is stable,while u=0 or u=1 is unstable under some assumptions,etc.  相似文献   

16.
IntroductionInthispaper,weconsidertheexistenceofsolutionsoffollowingboundaryvalueproblemonreallineforLi啨nardsystem :u″-f(u)u′ g(u) =0 ,u(-∞ ) =0 , u( ∞ ) =1 ,(1 )wheref:R →Randg :R →RarefunctionsofclassC1.Amotivationforourresearchisconne  相似文献   

17.
LetGbeaboundeddomaininthen-dimensionEuclideanspaceE",I相似文献   

18.
IntroductionInRef.[1 ]KannanandLockergivetheexistenceofatleastonesolutionofTy-h(t,y ,… ,y(n- 1) )y=f(t,y ,… ,y(n- 1) )   (a相似文献   

19.
This paper deals with the two type of mixed problems with respect to Neumannboundary and Dirichlet boundary for nonlinear pseudo-hyperbolic equations of generalizednerve conduction typeu_1-△u_1=F(x,t,u,(?)u,u_t,(?)i_t)when the nonlinear part F(x.t,u,(?)u,u_t,(?)u_t)and the initial values satisfy someconditions,the blow-up properties of the solutions are obtained.  相似文献   

20.
Some multiplicity results for an elastic beam equation at resonance   总被引:1,自引:0,他引:1  
This paper deals with multiplicity results for nonlinear elastic equations of the type-d~4u/dx~4+π~4u+g(x,u)=e(x)(0相似文献   

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