KHẢO SÁT PHƯƠNG TRÌNH PARABOLIC PHI TUYẾN TRONG MIỀN HÌNH CẦU
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KhilOsatphuongtrinhparabolicphi tuyin
trangmi~nhinhcdu
trang28
CHUONG4
sV TONT~I,DUYNHA.TvA ONDJNHNGHl~MT-TUANHoAN
CUAPHUONGTRINH NHIET PHI TUYEN.
Trongchuangnay,chungt6inghienClmnghi~mT-tu~nhoancua
baitoangiatribienphituySnsauday
(4.1)
(4.2)
(4.3)
(4.4)
Ut-(Urr+~Ur)+F(U)=f(r,t), O<r<l, O<t<T,
I
lim rur(r,t)
!
<+00,ur(l,t) +h(t){u(l,t)- uo)=0,r~O+
u(r,O)=u(r,T),
II
P-z
F(u) =u u,
trongd6 2~p <3, Uo lelcach&ngs6chotruac,h(t),f(r,t) lelcachams6
chotruacT-tu~nhoantheot,thoacacgiii thiStsau
(Hz)
(H;)
(H~)
UoE JR,
hE wi""(O,T),h(O)=her),h(t)~ho>0,
f E CO([0,T}H), f(r,O) =f(r,T).
Nghi~mySucuabaitoan(4.1)-(4.4)duQ'cthanhl~pnhusautu baitoan
biSnphansau:
Tim u ELZ(O,T;V)nL'"(O,T;H) saocho u' E LZ(o,T;H)vau(t)thoaphuang
trinhbiSnphansau:
(4.5)
T T
f(u'(t),vet)dt+J[(ur(t),vr(t))+h(t)u(l,t)v(l,t)}it
0 0
T
+ f(F(u(t)),v(t))dt°
T T
= f(f(t), v(t))dt+uofh(t)v(l,t)dt,'\IvE LZ(O,T;V),
0 0
vadi@uki~nT-tu~nho~m
H9CvienNguyln ViiDzilng
Khaosatphuongtrinhparabolicphi tuyin
trongmi~nhinhcdu
trang29
(4.6) U(O)=u(T).
Trong ph~nmlY,chungtoi sechungminhbai tmln(4.1)-(4.4)co
duynhatmQtnghi~my~uT-tu~nhoanvanghi~mnayclingemdinhd6ivai
I, h,uo.
4.1.S1}'tAnt~ivaduynhAtcuanghi~my~uT-tuftnhoan
Lienquaild~ns\l't6nt~ivaduynhatnghi~my~uT-tu~nhoancua
baitmln(4.1)-(4.4)tacodinhly sau.
Dinh If 4.1.ChoT>0 va(H), (H~),(H~)dung.Khi do,hai loan(4.1)-
(4.4)co duynhdtmr}tnghi?myiu T-tudnhoanU E L2(0,T;V)nL"'(0,T;H),
saDcho
u'EL2(0,T;H),rI/PUELP(Qr).
Chung minh.Chungminhg6mnhiSubuac.
Bmyc1. PhU'O'ngphap Galerkin. Ky hi~ubai {Wj},j=1,2,...la mQtcO'sa
tr\l'cchu~ntrongkhonggianHilberttachduQ'CV. Ta tim Urn (t) theod~ng
(4.7)
rn
urn(t)=LCmj(t)Wj'
j=l
trongdo Crnj(t), 1::;j ::;m thoah~phuO'ngtrinhvi phanphituy~n
(u~(t),Wj) +(urnr,Wjr) +h(t)urn(1,t)w/1) +(F(urn(t)), Wj)
=(/(t), Wj)+uoh(t)wj(l),1::;j::; m,
(4.8)
vadiSuki~nT-tu~nhoan
(4.9) Urn (0)= Urn(T).
f)~utien,taxeth~phuO'ngtrinh(4.8)vadiSuki~nd~u
( 4.9') Urn(0)=UOrn'
trongdo UOrn la hamtrongkhonggian m chiSusinh bai cac ham
Wj' j =1,2, Khi do, ta thuduQ'cmQth~m phuO'ngtrinhvi phanthuemg
H9CvienNguyln ViiDziing
Khaosatphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang30
phi tuySnv6i cac~nhamCmj(t),1<5,j <5,m,vacacdiSuki~nd~u(4.9').DS
th~yr~ngt6nt~ium(t) co d~ng(4.7)thoa(4.8)va (4.9')v6i h~ukhApnO'i
tren0<5,t <5,Tm'v6imQtTm'0<Tm<5,T.Cacdanhgiatiennghi~msaudaycho
pheptal~yTm=T v6i mQim.
Bmyc2.Danh gia tH~nghi~m.
NhanphuO'ngtrinhthu j cuah~(4.8)b6i Cmj(t),vasaudol~ytfmgtheoj,
taduQ'c
1
~llum(t)112+21IUmr(t)112+2h(t)u;(l,t)+2Jr2Ium(r,t)IPdr
(4.10) dt 0
=2(f(t),um(t))+2uoh(t)um(l,t).
Tir giii thiSt(H~) vab~td~ngthuc(2.9),tasuyrar~ng
(4.11) 211umr(t)112+2h(t)u~(l,t) ~CiliUm(t)II~,
v6i CI =mill{I,ho}.
Do do,tasuytir (4.10),(4.11)r~ng
:tllum(t)112+CIIIUm(t)II~+2fr2Ium(r,t)IP dr0
<5,2(f(t),um(t))+2uoh(t)um(l,t)
<5, ~llf(t)112+51IUm(t)112+;Iuonh[ +51IUm(t)II~
=~llf(t)112+;Iuonhll: +251IUm(t)II~,'15>0.
(4.12)
ChQn5>0 saocho
(4.13) CI-25=C2>0.
Do do,tir(4.12),(4.13)tathuduQ'c
H9CvienNguyln ViiDziing
Khao satphuongtrinhparabolicphi tuyin
trangmiJn hinhcdu
trang31
~llum (t)112+ C211um(t)112dt
I
~ ~llum(t)112+C21Ium(t)II~+2fr2Jum(r,tWdr
0
~;luol21lhll:+~Ilf(t)112=~(t).
Nhanb~td~ngthuc(4.14)b6i eCz! vasaudol~ytichphantheot tathu
(4.14)
duQ'c
!
(4.15) Ilum(t)112~lIuomI12e-Cz!+e-Cz! f~(s)eczsds.
0
Cho T >0, taxethams6sau
~
{
(eel!-It f~(s)eczSds,O<t~T,(4.16) R(t)= 0
hi (0) / C2, t = O.
KhidoRE Co[O,T].Ta d~tR =max~R(t).Ta thuduQ'ctir(4.15),(4.16)r~ngo,;,!,;,r
nSu lIuomll~R, khido
(4.17) Ilum(t)11~R, i.e.,Tm=T v6i mQi m.
GQi Bm(O,R)la quac~udongtam0, bankinh R trongkhonggianm chiSu
sinhb6i cachamWj' j =1,2,...,d6iv6i chu~n11.11.
Xet anhXI;!Fm :BJO,R) ~ BJO,R)chob6icongthuc
(4.18) Fm(Uom)= Um(T).
TasechungminhdngFm lamQtanhXI;!co.
Giasu UOm'VOmEBJO,R) vad~tm(t)=um(t)-vm(t),trongdo um(t)va vm(t)
la cacnghi~mcuah~(4.8)tren [O,T]thoacacdiSuki~nd~uum(O)=UOmva
Vm(0)=VOm'l~nluQ't.Khi do, m(t) thoah~phuangtrinh vi phansauday
H9CvienNguyln ViiDziing
Khaosatphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang32
«D~ (t), Wj ) + «D mr(t), Wjr) + h(t)<Dm(1,t)Wj (1)
(4.19) / p-z p-z \.
=-\lum(t)1 um(t)-lvm(t)1vm(t),Wj/'l~J~m,
vadiSuki~nd~u
(4.20) <Dm(O)=Uam-v am'
B~ngcachtinhtoangi6ngnhu6 chuang3,tathuduQ'c
~II<Dm (t)llz + 211<Dmr (t)llz+2h(t)l<Dm(l,t)lz
(4.21) dt
= -2(lum(t)IP-zUm(t) -Iv m(t)IP-zVm(t),um(t) - vm(t)) ~ 0
Nhavao(4.11),tasurtir(4.21)r~ng
(4.22) ~11<Dm(t)llz+C111<Dmr(t)II~ O.dt
Tich phanb~td~ngthuc (4.22),ta thu duQ'c
-.!.TC[
(4.23) IIUm(T)-vm(T)II~eZ IIUam-vamll,
i.e.,Fm:Bm(O,R)~ BJO,R) laanhx'ilco.Dodotant'iliduynh~tUamE Bm(O,R)
saocho Uam= Fm(uam)= Um(T).
Do do, v6i mQi m, tan t'ili m9t ham UamE Bm(O,R)saochonghi~mcuabai
toangiatrj band~u(4.8),(4.9')la m9tnghi~mT-tu~nhoancuah~(4.8).
Nghi~mnayclingthoab~td~ngthuc(4.17)v6i h~uhStt E [o,T]vanha
(4.14),tasurra
t t 1
(4.24) IIUm(t)llz+Cz filum(s)lI~ds+2fds frzlum(r,s)IPdr ~C3,
a a a
trongdo C3lam9th~ngs6d9Cl~pv6i m.
M~tkhac,b~ngcachnhanphuangtrinhthu j cuah~(4.8)b6i c~,l~ytlmg
theoj vasaudol~ytichphand6iv6i biSnthaigiantir0 dSnT, tathu
duQ'c
H(JcvienNguyin VflDzflng
KhilOsatphlfO'ngtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang33
T ITd IT d
fllu~(t)112dt+-f-llumr(t)112dt+- fh(t)-u~(l,t)dt
0 2 0 dt 2 0 dt
T
(4.25) +f(lum(t)IP-2Um(t),u~(t)}dt
0
T T
= f(J(t),u~ (t))dt+Uofh(t)u~(l,t)dt.
0 0
Tir (4.9') tath~yr~ng
Td
f-Ilumr (t)112dt =0,
0dt
T 1
f( )f(lum(t)IP-2um(t),u~(t)}dt=~fr2dr ~Ium(r,tr t0 P 0 0 dt
= ~fr2 ~um(r,T)IP -Ium (r,O)IP ~r = O.
Po
Do do,d~ngthuc(4.25),nhaitchphantUngph~n,tathuduQ'c
T T IT d T
(4.26) fllu~(t)112dt=f(J(t),u~(t))dt+- fh'(t)-u~(l,t)dt-uofh'(t)um(I,t)dt.
0 0 2 0 dt 0
Sail cling, nha VelO(4.24),(4.26),tasuyrab~td~ngthucsail
T T T T
2 fllu~(t)112dt ~ fIIJ(t)112dt + fllu~ (t)112dt +IIh'll",fu~(I,t)dt
0 0 0 0
T
(4.27) +21uolllh't]um(l,t)~t
0
T T T
~ fllu~(t)1I2dt +]IJ(t)1I2dt+411h'tfilum(t)II~dt
0 0 0
T
+41UolIlh'IL filum(t)lIvdt
0
T T T
~ fllu~(t)1I2dt +fIlJ(t)112dt +411h'tfilum(t)II~dt
0 0 0
+4v'Tlil, Illh'll.(~~m (')II~dtr
T
~ fllu~(t)112dt +C4 ,
0
KhilOsatphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang34
trongdo C4la ill9th~ngs6d9Cl~pv6'im.
V~y
T
(4.28) ~Iu~(t)112dt~C4, v6'i illQi m.
0
M~tkhac,tir(4.24)tacodanhgia
(4.29) Ids flr2!p'IUrn(r,s)IP-2Urn(r,sf' dr = Ids fr21urn(r,s)IPdr ~!C3'
0 0 0 0 2
BU'o-c3. Qua gio-ih~n.
Do (4.24),(4.28),(4.29)tasur ra r~ng,tfmt<;liill9t dayconcuaday {uJ,
v~nky hi~ula {urn}saocho
(4.30) Urn~ U trong LOfO(O,T;H)ySu*,
(4.31) Urn~u trong L2(0,T;V)ySu,
(4.32)u~~u' trongL2(0,T;H)ySu,
(4.33) r2!Purn~r2!putrongY(QT) ySu.
Tru6'chSt,tanghi~illl<;lir~ng
(4.34) u(O)=u(T).
V6'iillQi vEH, tacotir(4.9)r~ng
T
(4.35) f(u~(t),v)dt=(urn(T) - Urn(0),v)=o.
0
Tasurtir(4.32)va(4.35)r~ng
T T
(4.36) f(u~(t),v)dt~ f(u'(t),v)dt=0,khi m~ +00,
0 0
Tinh toantuongt\1'nhu(4.35),taclingcod~ngthuc
T
(4.37) (u(T)-u(O),v)=f(u'(t),v)dt=O,VvEH,
0
vadodo(4.34)dung.
H9CvienNguyln ViiDziing
KhilOsatphuongtrinhparabolicphi tuyin
trangmi~nhinhc6u
trang35
Dungb6dS2.11vStinhcompactcuaLions [3],apd\1ngvao(4.31),(4.32)
tacothStrichratirday{urn}mQtdayconv§,nkyhi~ula {urn}saocho
(4.38) Urn -) U m~nhtrong L2(O,T;H).
Theodinhly Riesz-Fischer,tir(4.38)tacothStrichramQtdayconcuaday
{urn}v§,nkyhi~ula{uJ saocho
(4.39) Urn(r,t) -) u(r,t) a.e.(r,f) trong QT=(0,1)x(O,T).
Do Uf-7IUIP-2u lien t\1C,taco
(440)
21'
I I
P-2 21 '
I I
P-2
. r P Urn(r,f) Urn(r,f) -) r P u(r,f) u(r,f) a.e. (r,f) trong QT'
Ap d\1ngb6dS2.12vSS\lhQit\1ySutrongLq (QT) v6i
, 2/' 2/' II P-2 2/' 2/' II P-2N=2,q=p,Grn=r PF(urn)=r Purn urn,G=r PF(u)=r Pu u.
Tir (4.29),(4.40)r~ng
(4.41) r2IP'lurnIP-2urn-)r2IP'luIP-2utrongy'(QT) ySu.
Ky hi~ug;(f)=~sinC:).i =1,2,...lamQtccysa tf\lCchu~ntrongkhong
gianHilbertth\lc L2(0,T).Khi dot~p{g;Wj:i, i=1,2,...}cfingthanhl~pmQt
ccysatr\lcchu~ntrongkhonggianL2(0,T;V).
Nhanphucyngtrinhthil i cua(4.8)cho g;(f),vasaildol~ytichphand6iv6i
biSn thai gian f, 0~f ~T, tathu duQ'c
T T
f( u~(f), Wj ;g; (f)<if+f( urnr(f), Wjr;g; (f)df
0 0
(4.42)
T T
+ fh(t)urn(1,f)w/1)g; (f)df +f(lurn(f)IP-2Urn(f), Wj)g; (f)df
0 0
T T
=f(f(f), Wj ;g;(f)df+fuoh(f)W/1)g;(f)df,Vi =1,2,...,m,Vi E N.
0 0
DSnghiencUuvSvi~cquagi6ih~ncuas6h~ngphituySnlurn(f)IP-2 Urn(f)
trong(4.42),tasud\1ngb6dSsail
H9CvienNguyin VfiDzfing
Khao satphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang36
BBd~4.1.
T T
J~~oof([urn(t)IP-2Urn(t), wi )gi(t)dt = f\lu(t)IP-2U(t),Wi)gi(t)dt, Vi, j =1,2,...
0 0
ChungminhbBd~4.1.
Chuyr~ng(4.41)tuO'ngduO'llgv6i
TIT 1
fdt fr2/P'[urn(t)IP-2urn(t)(r,t)dr~ ffr2/P'lu(t)la-lu(t)(r,t)dt
(4.43) 0 0 00
VE (U' (QT))=LP(QT).
M?t khac,taco
T T 1
f(lurn(t)IP-2Urn(t),Wi)gi(t)dt = f fr21urn(t)IP-2Urn(t)w/r)gi(t)drdt
(4.44) 0 00T 1
(= ffr2/p'IUrn (t)IP-2Urn (t)Xr2/PWi(r)g;Ct)}irdt.
0 0
Do (4.44),b6dS4.1seduQ'chUngminhnSutakhAngdinhduQ'cr~ng
(r,t)= r21 PWj (r)q:>(t) E U (QT)'Th~tv~y,dobfitdAngthuc(2.7),taco
TJ T 1
f f[(r,t)IPdrdt = f ~r2w/r)q:>(tfdrdt
0 0 0 0
1 T
= fr2-PIrw/rf dr flq:>(t)IPdt
0 0
(4.45)
1 T
~(FsIIWillvr fr2-Pdr]q:>(tWdt
0 0
T
~~(Fsllwill r nq:>(t)la+Jdt<+00.3- P v l'
V~yb6dS4.1duQ'chUngminhhmlntfit.
Cho m~ +00 trong(4.42),tasuyratll (4.30),(4.31),(4.32)vab6dS4.1,
r~ngu th6aphuO'ngtrinhbiSnphan
Khao satphuongtrinhparabolicphi tuyin
trongmi~nhinhcdu
trang37
(4.46)
T T
f(U'(t),wi )g;Ct)dt+ f(u,(t), Wi')g;Ct)dt
a a
T T
+ fh(t)u(l,t)Wi(l)gj(t)dt + f(lu(t)IP-2u(t),Wi)gj(t)dta a
T T
=f(/(t),Wi )gj(t)dt +Uafh(t)w/l)g;Ct)dt, Vi, j E N.
a a
V~y,tasuytu(4.46)r&ngphuangtrinhsaildaydung
T T T
f(u'(t),v)dt+f(u,(t),v,)dt+fh(t)u(l,t)v(l)dt
a a a
T
+ f\lu(t)IP-2u(t),v)dta
(4.47)
T T
=f(/(t),v(t))dt+uafh(t)v(l,t)dt, Vv E L2(O,T;V}
a a
V~ys\l't6nt~inghi~mduQ'chUngminhxong.
Bmyc4.Tinh duynh~tnghi~m.
Giasuu vav lahainghi~mySucuabaitmin(4.1)-(4.4).Khi do w=u-v
thoabaitoanbiSnphansailday
T T
f(w'(t), lp(t))dt + f[(W,(t),lp,(t)) +h(t)w(l, t)lp(1,t)}it
a a
T
(4.48) +f(lu(t)IP-2u(t)-lv(t)IP-2vet),lp(t)dt=0,
a
VlpE L2(0,T;V),
(4.49) w(O)=weT),
v6i u, VE L2(0,T; V)nD'(O,T;H), u', V'EL2(0,T;H), r2lpu,r21pvEH(QT}
T
L~y lp =w trong(4.48)va chuy r&ngf(w'(t),w(t))dt=o. Khi do su d\lng
a
(4.11)va(4.49),tathuduQ'c
Khao satphLfangtrinhparabolicphi tuyin
trongmi~nhinhcdu
trang38
(4.50)
1 r r
2C11Iw(t)II~2(o,r;v)~ fllwr(t)112dt +fh(t)w2(1,t)dt° 0
r
= - f(lu(t)1p-2 u(t) -lv(t)IP-2 vet),u(t) - vet))dt ~O.
0
DiSunaydfindSnw=0,i.e.,u=v.Dinhly 4.1dugcchUngminhhoant&t.
4.2.S1}'Andinb cuangbi~my~uT-tuftnboan
Trong phanll<lYchungt6i sekh~lOsattinh 6n dinh d6i v6i f, h,Uocua
nghi~mySuT-tuanhoancuabaitmin(4.1)-(4.4).
Tuang ung v6i f, h,uo, Ian lugt thoacacgia thiSt(H2), (H~),(H~),bai
loan (4.1)-(4.4) co duy nh&t mQt nghi~m ySu T-tuan hoan
u E L2(0,T;V)nL"'(0,T;H), saochou' E L2(0,T;H), r21puE LP(Qr)' Nghi~mnay
ph\!thuQcvaou=u(f,h,uo)Tasechungminhnghi~mnay6ndinhd6iv6i
f, h,UotheoillQtnghlamatasequidinhsau.
Tru6chSttad~t
H ={hE wi"" (O,T), h(O)=her),h(t)? ho>a},
y ={JE CO([O,T];H),f(r,O) =f(r,T)}.
Khi do,tacodinhly saudaylienquaildSntinh6ndinhcuanghi~mySu
Binb Iy 4.2.
Nghi<?mu=u(f, h,uo)6ndtnhdr5ivai f, h,uo,theongh'ia
Niu (fk,hk,uOk)'(f,h,uo)EYxHxJR, saocho
fk ~ f trong CO([O,T];H),
(4.51) hk~h trong w1""(0,T),
UOk~ u trong JR,
thi
(4.52) Uk~u trongL2(0,T;V)va r21puk~r2lputrongLP(Qr),
trongdo Uk=U(fk,hk,uOk)'u =u(f,h,uo).
Khaosatphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang39
Chung minh.
TruachSttad~themcackyhi~u
Vk=Uk-u, Jk =fk - f, hk=hk-h, UOk=UOk-uo.
ChovE L2(O,T;v) tllY y,truhaid~ngthucsau:
(4.53)
T T T
f(u~(t),vet))dt + f[(Ukr(t),Vr(t)) +hk(t)Uk(1,t)v(1,t)]dt+ f(F(Uk (t)),vet))dt
0 0 0
T T
= f(fk (t),v(t))dt+UOkfhk(t)v(l,t)dt,
0 0
Uk(0) =Uk(T),
(4.54)
T T T
f(U'(t),vet)dt+ f[(ur(t),Vr(t))+h(t)u(l,t)v(l,t)]dt+ f(F(u(t)), vet)dt
0 0 0
T T
=f(f(t),v(t))dt+UOk fh(t)v(l,t)dt,
0 0
U(O)=u(T),
tathuduQ'c
(4.55)
T T
f(v~(t),vet))dt + f[(Vkr(t),Vr(t)) + (hk(t)Uk(l,t) - h(t)u(l, t))v(1,t)]dt
0 0
T
+f(F(Uk(t))-F(u(t)),v(t))dt
0
T T
=f((Jk(t)}v(t))dt+f(UOkhk(t)-uoh(t))v(1,t)dt.
0 0
Chnv=Vk'trong(4.55)vasaukhi chuy r~ng
T 1Td 1 1
(4.56) f((v~(t)),Vk(t))dt=- f-lIvk (t)lldt=-llvk(T)II--llvk(0)11=0,
0 20 dt 2 2
tathuduQ'c
Khaosatphuangtrinhparabolicphi tuyin
trongmi~nhinhcdu
trang40
(4.57)
T T
fllvkr(t)112dt + f(hk(t)Uk(l,t) - h(t)U(l,t))vk(l,t)dt
0 0
T
+ f(F(Uk(t))- F(u(t)),Vk(t))dt
0
T T
= f(Jk (t),Vk(t)}dt+ f(UOkhk(t) - uOh(t))vk(l,t)dt,
0 0
hay
T T T
flhr (t)112dt+ fhk(t)vi (l,t)dt +fhk(t)u(l,t)vk(l,t)dt
0 0 0
T
+f(F(Uk(t))-F(u(t)),Vk(t))dt
0
(4.58) T T
= f(Vk (t)) Vk(t)}dt+UOkfhk (t)Vk(l,t)dt
0 0
T
+uo fhk(t)vk(l,t))dt.
0
Chu y r&ng
T T T
(4.59) ]IVkr(t)112dt+ fhk(t)vi (l,t)dt ~ C) ]h(t)II~dt=c)llvkll~2(O,T;V)'
0 0 0
trongd6 C)=mill{1,ho}.Dung bfitd~ngthuc
(4.60) '\Ip~2,3Cp>O:~XIP-2X-lxIP-2XXX-y)~cplx-yIP'\Ix,yeIR,
tasuyra
T T )
(4.61) f(F(Uk(t))- F(u(t)),Vk(t))dt~Cpfdt fr21uk(t) - u(t)IPdr =Cp IIr2/PVkII;p(Qr)'
0 0 0
B&ngeachsird\lngbfitd~ngthuc(4.60),tasuyratll (4.58)-(4.61)r&ng
c)llvkll~2(O,T;V)+Cpllr2/Pvkll;p(Qr)
(4.62)
T T
~ - fhk(t)u(l, t)vk(1,t)dt + f\Jk (t),Vk(t)}dt
0 0
T T
+UOkfhk (t)Vk(l,t)dt +Uofhk(t)Vk(l,t)dt
0 0
H9CvienNguyln ViiDzilng
Khaosatphuongtrinhparabolicphi tuyin
trongmiJn hinhcdu
trang41
T T
S 411hkt fllu(t)llvIlvk(t)llvdt + Illkllco([O,T];H) fllvk (t)llv dt
T T
+ 21uOkIllhkt ~h (t)llv dt + 211hkt Iuol fllvk (t)IIv dt° °
S 411hkIIJuIIL2(O,T;V) IlvkIIL2(O,T;V)+ Illk Ilco([o,T];H)Frllvk t2(O,T;V)
+ 21uOkIllhkt Frllvk t2(O,T;V) + 211hkt IUDIFrllvk IIL2(O,T;V)
=[2(21Iut2(O'T;V)+Frluolllhkt +Frlllkllco([O,T];H)+2FrllhkIUuOkl]lvkt2(O,T;V)
==8k IIVkt2(O,T;V)'
tfongdo
(4.63) 8k =2(21IuIIL2(O'T;V)+Frluol)llhkt +Frlllkllco([O,T];H)+2FrllhktluOkl.
Ta Suyfa tu (4.62)dng
1
(4.64) Ilvk(t)112( . ) S-8k'L O,T,V C )
2 ~
II
21
li
P 1 82
(4.65) c)llvkIIL2(O,T;V)+CprPVkLP(QT)SC) k'
1 821P
11
21p
II SD~k'
(4.66) r Vk LP(QT) ~C)Cp
1 1 821P
II II
21pV
II <-8k + D~ k .
(4.67) Ih L2(O,T;V)+ r k LP(QT)- C) ~C)Cp
Tu giathiSt(4.51),taco
Il
hk
II
~ 0,
Il
lk
II
~ 0, IUOk I ~ 0,
00 CO([O,T];H)
vadays6~Ihkt } bi ch~n,nen8k ~ O.
V~y
1 1 821P ~ o.
I II II
21pV
II <-8k + D~ k
IVk L2(O,T;V)+ r k LP(QT) - c) ~C)Cp
Dinh ly 4.2duQ'chungminhhoant~t.