Structure intrinsèque du Web

Texte intégral

(1)Structure intrinsèque du Web Fabien Mathieu, Laurent Viennot. To cite this version: Fabien Mathieu, Laurent Viennot. Structure intrinsèque du Web. [Rapport de recherche] RR-4663, INRIA. 2002. �inria-00071922�. HAL Id: inria-00071922 https://hal.inria.fr/inria-00071922 Submitted on 23 May 2006. HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés..

(2) INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET EN AUTOMATIQUE. Structure intrinsèque du Web Fabien Mathieu et Laurent Viennot. N° 4663 Décembre 2002. ISSN 0249-6399. ISRN INRIA/RR--4663--FR+ENG. THÈME 1. apport de recherche.

(3)

(4)

(5)

(6)

(7) !#"%$'&(*),+!-"%./"0) 12 .34"%$5)768!#"0$$9 ) :;=<4>@?ACBED2F4GH?4IKJ=LM?NOGHPQGRNS<>@?4G T USVKWR?N2XYPZUSV\[]?4^ DOIK_=_ VÙHN2aQ?bUH?dce;=?Uece;=?gf hi0j`j0klB mCF4c?>^=UH?on`p`p0nbBrqs_*IKt0?4G. uMvw4xy\z={`x`| :;=?[}?^~tÙeIK_=;l;*I`GY^ ??f~[aQ?PIà=V`_QNS?4aI0GCNH;=?cV0UH?@aQ?dGHcUH^=f=tMNS;=?@[]?4^~G NHUSJ*cNHJ=US? ndOV\[]?4`?4U4 NHNH?IKN NS?f%NHV`f;*I0G2^ ??4f_*IKaNHVMNH;=?sUH?4IKNHV`f*GH;=_^?NR[]?4?f8NH;*?s[}?^t0USI`_=;IKf*aNS;=?sVQcI\NSV0fVKNH;*?s_*I`t`?4G4NC;I`G IÙS?4I0aQP ^ ??4flf*VKNHc?da8NH;I\Nf=QGIKUS?oVKNS?fVQcI`}- ?ÙSV`>I7_IKt`?sNHVIKf=V`NH;=?4UC_*I`t`?VKNH;*?GSIK>@?GH?US`?4Ue2IKf*aNH;=G c4IKf8^?J*GH?4a V0U?7c?f%NOcVQaQf=t@VK NH;=?b[}?^8t0USI`_=;QQi`# VZc4IKNRPf NH;=?b[}?^8cI`fM^ ?J=U NS;=?U>@VQaQ?4?4a ^ZPMI¡¢¤£Z¥§¦©¨ªS¨S«s¬KªHe®=¯8a=?°*f=?da^%P Ià=aQf=tNH;=?b_*UH?°=LNHUS??VK±OD2 G NSVNS;=?[]?4^Mt0USI`_=;²NSG}f0NS?USf*IK³f=VQaQ?dGIKUS?2NS;=?bcV`>@>@V`f _=US?°=LQ?4G}V`±ODO GIKf*a NSG}?dI,`?dG]IÙH?CNH;=?b±CD2 G}NS;=?>GH?`?4G4 ´ GCGH;=V\[f8^ZPµt`J=US?7A`³I_=US?°*L VÙeaQ?4UHf=tVK ±CD2 GYI`c4cVÙeaQf=tNHVMNH;=GNSUH?4?sIKV\[2G2J*G2NSV7V`^G ?4UH0?YVQcI` G NHUSJ*c§NSJ=UH?sf NS;=?o[}?âQUH?dc§NSP V`f8NH;*?sIà,W I0c?4f*cP7>IKNHUSL¶·V` NS;=?o[}?^t0USI`_=;²}¶¸GH_=NSGOf8NR[}V@NH?4UH>Gb¹¶»º'¼¾½À¿*[;=?4UH?o¼ GOaQIKt0V`f*I`5^ZPM^=VQceZGI`f*a¿ÁG _IKUeG ?4U]NS;*IKf¼]:;=?o^*VQceQGVK¼ÂNH;*IKNCcI`f8^?oV0^*GH?US`?4a V`fNS;=?saQIKt0V`f*I`²IKUS?GH?NeGVK _*I`t`?dGGRNSUHV0f=t`PUH?4IKNH?da7NSV`t`?NH;=?4U4 ÃÄ%Å³ÆHÇÈ y\Éw`|ËÊ ?^XYUSI`_=;²=: UH?4?`=Ì}VZceQG4Í]JGRNS?UeG. Unité de recherche INRIA Rocquencourt Domaine de Voluceau, Rocquencourt, BP 105, 78153 Le Chesnay Cedex (France) Téléphone : +33 1 39 63 55 11 — Télécopie : +33 1 39 63 53 30.

(8) Á

(9) r

(10)

(11) w

(12) | ²?t0USI`_=;=?Ca=J [}?^8IsIKUSt`?4>@?f%N}FNHFbIà=V`_QNSFC_ V`J=UUS?_=USF4GH?f%NS?U}I@G NHUSJ*c§NSJ=UH?aQJ[]?4^n, fUH?4,I`f*ce;=?0%? ?4f@?f%NHUS??t0USI`_=;=?aQJ@[]?4^@?N ICVQcI`GHIKNHV`f@aQ?4G_IKt`?dG[]?4^@?4G NUeIKUS?>@?4f0NJQNSG F0 TV`J*U NeIKf%N40*IaQF WFNSFUH?4>@IÙ%J=F %J=?I7_=J*_*IKUHNYaQ?dGY;%PZ_ ?US?fG2FNeIK?f%NYa=?f*IKNHJ=US?oVQcIK? - ?`YUS?I`f0NaQ?J=L8_IKt`?dGOa J=fl> 4>@?GH?US`?J*Ue?N %J=?c?4I _ ?US>@?N NeIKNOaQ?bUSF4IKG ?4U}J*f?4f*cVQa=I`t`?Y?7cI0c?baQJ8tÙeIK_*;=?Ya=J[}?^~Q=i\ IoVZc4IKNSFCa=I`f*G}?CtÙeIK_=;*?CaQJ []?4^MG ?CVÙS>IKGH?2?4fMf0NSUHVQaQJ*GSIKf%N]Iof*VKNHV`faQ?Y¬`ªHe®=¯=¨¨ ¡¢¤£Z¥§¦©¨ªe¥§ZaQF°f=5cV`>@>@? I0a,WRV`fc§NHV`fÀaQ?M IÙH^*UH?Ma=?4G_=UHF°=LQ?4GaQ?4G±OD2 GI`J tÙeIK_*;=?` ?4Gsf bJ*a=Gf%NS?USf=?4GG V0f0N?dGs_*UHF°=LQ?4GscV`>@>sJ*f*GsaQ?dG ±CD2 GYNeIKf*aQG %J=?@?dGC?J=?4GbGHV`f%N?dGb±OD2 G??d"G !# > >@?4G4@Í]V0>@>??>@V0f0NSUH?IM°t`J=US? A05J=flNHUS aQ?4Gb±CD2 Gba=I`f*G V0USa=UH??LQcV`t0USI`_=;=$ %J=?}I0GHGHVQc%F bc?N]IKUS^=US?}f*V`J*G_ ?US>@?N]&a V0^*G ?4UH0?UIbVQc4IKNSF2aQ?4G;ZPZ_ ?US?f*G aQUS?4cNH?4>?4f%'N _*IKUHNHU aQ?I>I\NHUSc?a Ià,W I0c?fc?7¶ aQJ t0USI`_=;=?@aQJ []?4^² ´ f*GHNHUSF4?` ¶ G ?7a=F4cV0>@_V%G ?ZGHJ=??>@?f%No?f aQ?4JQLNS?US>?dG@¹ ¶rº/¼ ½l¿0)V (7¼ ?4G N]aQIKt0V`f*I`?_IKU ^*VQcG]?N¿ J=f=?C>@IKNHUSc?OcUS?JG ?O¼ ?4G ^=VQc4G aQ?Y¼ cV0UHUS?4GH_V0f*aQ?4f0*N saQ?4G _*IKt0?4G V0U NS?>@?f%N2US?F4?4G}?f%NHUS???dG + È x4w Æ ){ , w |ËÊ ?4^²XYUeIK_=;*?4G4 ´ US^=UH?dG=Ì}VQcG4Í]J*G NH?4USG.

(13) 4¡eK¢¦#ª§£*¡¦-£QªH¨ l¦¯*¨@¨. k. µt`J=US?@A`¹

(14) VZV`> GHJ=UI@aQI`t`V0f*IK?Ya=?bI>I\NSUHc?ba Ià,W I0c?4f*c? IUS?_*UHFdG ?4f0NeI\NSV0fMcI`GSG $ %J=?baQJ[]?4^cV`>@>@?YJ*ft0USI`_=;=?Yf& JQNHGH?b_*I`G f%NHF4tÙeIKNSFYaQ?dGaQV`f*f=F?dGGRNSUHJ*cNHJ=US??4GaQJ [}?^² * FdcUSNSJ=UH?CGRNeIKf*a=IÙSa=GHF?2aQ?dG ±CD2 G4 %J=?O V`f7_ ?J=N]US?_=USF4GH?f%NH?4U _*IÙ J=fMIÙH^=US?`0f& ?4G N _*I`G _=USGH?2?f cV`>@_QNS?` 2V0J*G I`V`f*G]aQV`fc2aQF°f=U}J=f=?YaQV`J*^=?CGRNSUHJ*cNHJ=US?`ZI,`?dc?CtÙeIK_=;*?2aQ?4G ;%PZ_ ?US?fG a J=fMcKNHF00IoVQcI`GHIKNHV`fa=I`f*G IÙH^*UH?2aQ?dG ±CD2 G2a=?b IKJQNSUH?@¹?baQF4cV`J=_*I`t`?Y?fcJ*G NH?4USGa J=f8tÙeIK_*;=?`. Ä zQy

(15) Ä | IG NHUSJ*c§NSJ=US?7aQ?l¡¢¤£Z¥§¦¨ªHë«M¬`ªHS®*¯ f ?dGRNs_I`G %J& J=f V0^QWR?N 0«-¯d¡Mf%NHUSVQaQJ=Ns_ V`J=UoFNHJ*a=?4Us?[]?4^² ©f%NHUSVQaQJ=NH?% V0UHt`f=?_*IÙ µ=?f*toa=IKf*G2 k,_V0J=U IKaQ?4U IZG J*I`GSI\NHV`faQ?2t0USI`f*a=GtÙeIK_=;*?4G4K??_ ?J=N IK_=_*IÙSINSUH?a=I`f*G aQ?NSUH<dGOf=V0>s^=US?J=LcV`f%NH?LZNH?4G¹C_*IKUY?LQ?>@_=?`5?tÙeIK_=;=?aQ?4GYUS?I\NSV0f*GO;ZJ=>I`f=?dG@?4GG V0>@>?NSGGHV`f%NYaQ?dGY_?4USGHV`f=f*?4G ?N ¾_V0f%NH?`?4USG ÂGH cV0f=f*I N 2_ ?J=NGH?scV0>@_=FNH?4UYaQ?>IKf=<US?s_ ?UHNHf=?f%NS?s?fJ=fÁ¡¢¤£Z¥§¦¨ªHë«¬KªHe®=¯Q²V ( IÙH^*UH? Z?f%NOaQ?bIVQcI`GHIKNHV`f~_*I,PQG4²FNeI\N§§=Z?` %J*IÙ NS?4U4ZUSJ=?`54e§ . !. e . ±Of aQFdcV`J*_*IKt0?2?fMcJGRNS?UeG]a J=f7t0USI`_=;=?#"%$'&)(+*-, ?4G N}IoaQV0f=f=F?Ya J=f cV`J=_=?.$0/1(324,%V)(5/ 4? G N]J*f IKUS^=US? 76 &86K?J*?dG ?N.2 J*f=?7^= WR?4cNHV`f ?4f0NSUH??4Gb?J=?4GaQ?5/ ?N?dGoG V0>@>?NSGaQ?8"@:9 ce;*I %J=?f bJ*a<; aQ ? IKUS^=US?7cV0UHUS?4GH_V0f*alJ=f=? _*IÙ NS?=&>@?BA CEDF$G;H,aQ?-& aQF°*f=?b_*IKUb¹ M 2Q$0;H,SR =GH ;UT?J*?dG $0/, N &I>@?BA CEDJ$G;H,LKº O#P V &>@?BA CEDJ$G^_,=GH ;aT ` ?J=?d G $0/, W<XY ZB[ \]. bbdcfegFhJhJi.

(16) ¨\¦¯ ¨£¨¦4 \£QªH¨*¦H¨ K ¦ i. 5

(17) b 's @

(18) o

(19)

(20)

(21) ?btÙeIK_=;=?aQJ8[}?^ _ V0GSG <daQ?J=f=?bcJ*G NH?USGHIKNHV`f<$G/1(+2,}fI\NHJ*UH?4?f*a=J=NS?b_*IKU F4cUSNHJ=US?baQ?4G±CD2 Gb¹ IUeI`cf=?baQ?/(?4G N2FNH$%J=?NSF?_*IÙ,;%N NH_` NHV0JQNH?o±CD2 ?4G N2aQ?bIV0UH>@?c?UHNSIKf=?dGce;*If=?4G_ V`J*,I`f%N NHUS?%aQ?dGSY¹ !"#%$%&'#()#%*,+"-/.0#1*%+"-*%&+2.43"$6578:9)*;.4<$19)*=>)$1+"?%+"*%A@B;..".C%+?*D"9),E)8F681*%+2.4*,G" ?@G ?_=I`c?cV0>>@?s?J=?@aQ?s IÙH^*UH?o?4flGHJ=,I`f%NC?ce;=?4>fÀ?dGOf b J*a=GCf%NH?4UHf*?4GYG V0f0NcUSFFdG 7 I70V`F?sG G f& ?LQG NH?4f%N_I`Ge ;%N NH_'HJ4I V`f=?DH aQV0>IKf=?6H G ?4UH0?J=UeG4 GHV`J*G©! G ?4UH0?J=UeG _ VÙRNKH USF_'L2/ H 40H UHF4_ ] H °ce;=?Ud ?LZN ²?dGaQN³M FUS?f%NeG}°*GOa J*f>#4 >?bf b J*a GHV`f%NUeIKf=t0F4GIÙH^=NHUeIKUS?>@?f%Ne]_*IÙVÙeaQUH??LQcV`t0USI`_=;=$% J=?` TIKUYcV0f*GRNSUHJc§NHV`f IÙH^*UH? % J=?f=V`JGCcV`f*G NHUSJ=G V0f*G2IKf*GH ?dGRNY^=?fJ=f~aQF4cV`J=_IKt`?b?4fcJ*G NH?4USGYaQJt0USI`_=;=?saQJ[]?4^² I°*t`J=US?on?4G N2J=f?LQ?4>_*?oaQ?bIG NHUSJ*c§NSJ=UH?NRPZ_=$% J=?oa J=ftÙeIK_*;=?bcJ*GRNS?USGHF`=cV`f*G NHUSJ=N @ _*IKUHNHU2aQ?% J=?4 % J=?dG2±OD2 G . IÙH^=NHUeIKUS?4G4. P Q R ] V`f cV`f*GHa=<US?#% J=?I8_=J=_*IÙ NsaQ?dGocV0f*c?4_QNH?4J=UeGoaQ?7GHNS?7?4GSGHI`?4f%Nba& I,0VÙYJ*f=?Mc?4U NeIKf=?@VÙSt0I`f=GSI\NSV0f²²IKJGHGH ^=?f I`J f=`?4I`J aQJ _IKUec7aQ?M>I0ce;=f*?4G % J& GV`f%NF4`?4f0NSJ=??>@?f%N aQGH_ V0GHNSV0f % J& I`J f=`?dIKJ aQ?dGsUSF_ ?UHNHV0US?4Gb?NGHV`J*G! USF_ ?UHNHV0US?4G4KV`fcV`>@_=US?f*a% J=?2?tÙeIK_=;=??4f@cJGRNS?UeG aQJ@[]?4^@,I NHUS?f%NS>@?>@?4f0N]F% If*VKNHV`faQ?2GHNH?2[}?^²0cV`>@>@? NS?f*aQ?4f%N ?@cV`fQ°UH>@?UY?4GaQSM F4UH?4f0NS?4GYV`^G ?4UH\I\NSV0f*GOIKNH?4GGHJ=UI >I\NSUHc?@a Ià,W I0c?fc?¶ a J=f~cUSI,[?K³M ?4cNHJ=FGHJ=U _=J*G]aQ?2;ZJ=N >@V`fG aQ?OGHV`>@>@?NeG ?4fWRJ=fMn`p`p*A`V0U°t`J=US?bAd * V0UHt%IKf=GSI\NHV`faQ?4G G NH?dG GH?2UH?NHUSV`J=0?G J=U Ib>IKNHUSc?` ?NJ=f=?aQF4cV`>@_ V0GHNSV0f ¶ º ¼ ½'¿V ( ¼ ?dGRN@aQIKt`V0f*IK?_*IÙs^=VQcGo?N@¿ J*f=?7>I\NSUHc?McUH?4J*GH?M¼ IK_*_*IKUeIN4 ?4G ^=VQcG2cV%#T f*caQ?4f0Nd=IK_=US<4G}ZFUS°cIKNHV`f²QUS?>IKU % J*IK^*?4>?4f%N]^=?fI,`?dcY?dGfb J*a=Gf%NH?USf=?dGaQJaQF4cV`J=_*I`t`?cI`f=V`f=$% J=??f cJ*G NH?4USGVU ?f8P7US?t%IKUea=IKf%NaQ?b_=J*G_=US<4G4=c?oaQFdcV0J=_*IKt0?YI`JQNHV0UHGH?YJ*f=?bZGHV0f USF4cJ=UeG `?@?N2_=JG°*f=?,aQJ8_=USV`^=<>@?baQ? IaQF°f=NSV0fa& J=fGHNH?[]?4^²TIKU?LZ?4>@_=?@¹ ±2f=?oGHVQcFNSFY_ ?J=N% NHUS?b;=F4^?4UHt0F?G J=UW"W"W .>X'86Y'(F1$65))7,Y,9Z2.[F1$65'?\ G V0fa=F_*IÙ NS?>@?f%N2aQ?bUS?4ce;=?4USce;=?YG NHJ*FoG J=UW"W"W .>X'86Y'(F1$65))7,Y,9Z2.[F1$B5]D+?*)#1*7%+F^?\ ?N2?4G_*I`t`?dG}a=?``_ V0;=f R >NH;'a a=IKfG2WW"W .>X]8BY'(F%$B5))7,Y9"Zb.0FD$65]1+*?#%*"71+FB)c"#:586,)\ OV`J*Gb_ V`J*`V`fGbaQ<4GbVÙeG?f%NSUH?4`VÙ?dG>@V\P`?fGbaQ?7aQF°f=UGRNSUHJ*cNHJ=US??>@?f%Nsc? % J& ?4G NoJ=f GHNS?[]?4^²7T JQN3`N % J=? a Ià=V`_QNS?U7I aQF°f=NSV0f f%NSJ=NS0?_=USV`_ V0GHF?_*IÙA#f=V0J*G7IK_*_?4?USV`f*G¥J¦©ëd ¨ J=f ?f*GH?>^=?V0UHt%IKf=GHF8a=?_*IKt0?4G _=USVQce;=?4GMa=IKf*G@ IKUS^=UH?a=JÁ[}?^ ?N7VÙHNH?4>?4f%NMcV`f*f=?4cNHF?dG?f%NSUH??4?4G7a*IKf*G?tÙeIK_*;=?aQJ []?4^² NM_=JQN3`N % J=?aQ? NSUSI,\IK?4UOG J*UO ?4f*G ?4>s^=?a=?4G2_IKUHNHNHV`f*GCaQ?4GYG V0>@>?NSGCaQJtÙeIK_*;=?` c? % J= f& ?4G NCt`J*<US?oUHFdIKGSIK^*?b?4f_=UeI\NH$% J=?`?4G N _ V0GSG ^=?baQ?bG ?YUH?dGRNSUH?4faQUH?@I`JM>@V`f*G_ V`J=UcV`>@>@?f*c?U§]I`JQL7_*IÙ NSNSV0f*G}f*a=J=NS?4G_*IÙ?dGfb J*a=G}f0NS?USf=?4Ga=?C IÙH^*UH? aQ?dG2cJ*G NH?4USG4 ?4GIK_*_=cIKNHV`f*Ga& J=f*?b_*IKUHNHNHV`f8aQJ8tÙeIK_=;*?a=J[}?^?f~¥J¦©¨§¥ d ¨ oGHV`f%Nf=V`>^=UH?4J*GH?4G4;Cf f8_ V`J=USUeIKN}_*IÙ?LQ?>@_=? IÙS?bI@aQG NHf*c§NSV0f?f%NHUS??dG?fGf%NS?USf=?4GaQ?sf*I,Zt%I\NHV`f f%NSFUS?4J=UOa J=fG NH?b?NO?4G?4f*G?L%NS?USf=?4G4QfQVÙS>I\NHV`f JQNS?OGHQ V`fI`N ;ZPZ_ VKNH;*<4GH? % J=??4GGH?4cV`f*a*GG V0f0N_=J*G>@_V0U NeIKf%NSG% J=??4G_*UH?4>?UeG4 ²?t0USI`_=;=?! % J=V`NH?f%N GHGHJa J=f=? NS??}_*IKUHNHNHV`fG ?4USI`N^?dIKJ*cV`J=_o_*J*G _ ?NHN4`>@I`G f=FdIKf=>@V`f*G _?4U NSf*?f%N4mO?dG I`t0VÙSNS;=>@?4G cV`>@>@? ?}TI`t`?dD2IKf=YJQNSGHF _*IÙXYVZV0t`?O_ V`J=USUSI`N NSUH?cI`cJ=FYaQ?Y>@I`f=<US?CaQGRNSUH^=J=FGHJ=U]_*J*GH?J=UeG}f=0?4I`JQL50_*IÙ]?LQ?>@_=?Cf%NHUeI ©! G NH?C?Nf%NH?4U©! GHNS?` O. ' ihkj\7M ml oon TV`J*Uc?dG²UeIKG V0f*Gf=V`J*G cUSV\P`V0f*G 0 J*?I2G NHUSJ*cNHJ=US? aQJb[}?^?4G N>@?4JQL>VQaQF4GHF?_*IÙ²?]cV`fc?_=NaQ? tÙeIK_*;=?cJ*GRNS?USGHF` ²? aQFdcV0J=_*IKt0??fcJ*G NH?UeG a J=f@tÙeIK_*;=?_?4JQN VÙS>@??4>@?f%N NSUH?2aQF°*f=*cV`>@>@?J=fIKUS^=US?}?N J=ftÙeIK_*;=?UH?4IKf%N?dG?J*?dG aQ?b IKUS^=UH?0 IUH?4_=UHFdG ?4f%NSI\NSV0fMaQJ8[}?^?f NH?US>@?4GaQ?ocJGRNS?UeG}a& J=f8t0USI`_=;=?Y_?4JQNOIKaQ?U% aQ?f%NS°*?4U2GRNSUHJc§NHJ*UH?4?>@?f%N ?4G]G NH?dG [}?^²0_*IKU]?LQ?>@_=?2?4f7G F4?dc§NHV`f*f*IKf%N ?4G fb J*a=G f%NH?4UHf*?4G a=?2 IKUS^=US?2cV0>>@?2?4f*GH?>s^*?Oa=?OcI`f*aQa=I\NeG f=NSI`JQL5 m I`JQNHUS?4GI`_=_=c4I\NSV0f*GG V0f%N_ V0GSGH^=?4G¹ pCq csr>tBuvwr>t6uCx6vzy6u;{}|b~^rC4 g. bA.

(22) 4¡eK¢¦#ª§£*¡¦-£QªH¨ l¦¯*¨@¨. . ;%N NS_²¹. . V0UHt >sPQGHNS?. VZV. GH>@NS; . . cV`>. f*aQ?L5 ;%NH>@. f*aQ?L5 ;%NH>. t0VZV`t`? [[[. [[[. [IKUSf=f*t* ;0NS>. °G ;*f=t. ^*IÙ [[[. a=V\[f=V%Ià aQV\[f=V0I0a5 ct`. f*aQ?L³ ;%NH>@. fZJQL f*aQ?L5 ;%NH>. f*a=?L5 ;%NS>. f=QG4 ;%NH>. ^*IKNSG f*aQ?L5 ;%NH> . ?4G4 ;0NS>. []V0UH>G4 ;%NH> µt`J=US?onQ¹ LQ?>@_=?oaQ?M¡¢¤£Z¥§¦¨ªHë«o¬`ªHS®*¯. bbdcfegFhJhJi. f*aQ?L5 ;%NH>@.

(23) j. ¨\¦¯ ¨£¨¦4 \£QªH¨*¦H¨ K ¦. VQaQ<?4G_*UHV0^*IK^=G NH?dG}a=Jt0USI`_=;=?baQJ8[}?^^*I`GHF4GGHJ=UIG NHUSJ*cNHJ=US?ba IÙH^*UH?!#t0USI`_=;=?` Í}IKcJ=aQ?dGYcVÙSUHF4IKNHV`f*GO?f%NHUS?s?4GY_*IÙSI`>@<NHUS?4GCaQ? IKUS^=US?aQJl[]?4^?Noc?4JQLaQJ~tÙeIK_=;=?aQJ[}?^²bTIÙC?LZ?4>@_=?0 aQ?4GcVÙSUHF4IKNHV`f*GGHJ=U?4GaQGRNeIKf*c?4G_ ?US>@?N NSUSI`N2a I,`V0UJ=f8>@??4J=U2cV0f0NSU30?GHJ=UI % J*I`NHFbaQ?dGcUeI,[G}USF?4G4. bA.

(24) 4¡eK¢¦#ª§£*¡¦-£QªH¨ l¦¯*¨@¨. q.

(25) j\

(26)

(27) }

(28) A= 2ce7Í]USI0G [}?-0mCI,ZaCI,[Zf=t0I`f*a R NH?4_=;=?4f7DV`^ ?UHNSGHV`f² =M³?4cNH`?OGHNS?°*f*a=f=tbJG f=tof*I`f*ce;=VÙfQV0UH>I\NSV0f² © f O¨¥¨SKªH¡e¯ ³« ¨ \¨@¢ S® @¨ *!¦

(29) F\ª \¦'0 O¨¦#ªJ¨\\¢¤*_*IKt0?4G2n``p=n`0qQ%n`p`p=A0 n, ´ faQUH?4 Ì}USVZa=?U?NYIK#}XYUeIK_=;G NHUSJ*c§NSJ=UH?bfNH;=?s[]?4^² © f }+ª 4¡ K¦. ¯ *¦©¨ª \'¦ 0 ³\¢ \ª§¢« «`Ü@¨ )

(30) ¨ªH¨ ¡e¨ _*I`t`?4Gk0p Zk0n`p=ZnKp`p0p= k\ Cf=t`[}?fµ*?f=t DV0^?4U Nµ}5Í]V0;=?f²³IKfa8T?NH?4U I0aQ?4G4OOV\['NSVMaQUeI,[gI_=IKf*IÙCcJ*G NH?4UH?da8tÙeIK_=;² K£Qª \¢ ¦¯*¨ ! " 0 =¹nQA Zk=A0=

(31) A #0= iK` _XYJ=IKJ=>@?0 = IKNSI`_%P0=IKf*a % $O?f=f=V`N4 7c?4f0NOI`f*a8G >@_=?Y?4f*cVQaQf=t%G}VÙNH;*?b[]?4^t0USI`_=;²=nKp0p0n= , &@DOIKf*a=I`#³Db R NeI\NeI=³Db Ê ceZUH?4>@?4GHf=t0;=?ÌKf* a _ Ê ?f=?4U42:;*?sf=8a=IKNSIKÎ`GH?`¹]µI`G NCI`c4c?dGHGNSVMt0USI`_=;*GV`NS;=? [}?^²n`p`p*A`. bbdcfegFhJhJi.

(32) Unité de recherche INRIA Rocquencourt Domaine de Voluceau - Rocquencourt - BP 105 - 78153 Le Chesnay Cedex (France) Unité de recherche INRIA Lorraine : LORIA, Technopôle de Nancy-Brabois - Campus scientifique 615, rue du Jardin Botanique - BP 101 - 54602 Villers-lès-Nancy Cedex (France) Unité de recherche INRIA Rennes : IRISA, Campus universitaire de Beaulieu - 35042 Rennes Cedex (France) Unité de recherche INRIA Rhône-Alpes : 655, avenue de l’Europe - 38330 Montbonnot-St-Martin (France) Unité de recherche INRIA Sophia Antipolis : 2004, route des Lucioles - BP 93 - 06902 Sophia Antipolis Cedex (France). Éditeur INRIA - Domaine de Voluceau - Rocquencourt, BP 105 - 78153 Le Chesnay Cedex (France).

(33). . ISSN 0249-6399.

(34)