Automatically Combining Ranking Heuristics for HTML Documents

Transcription

1 Automatically Combining Ranking Heuristics for HTML Documents Joaquin Rapela IBM Almaden Research Center San Jose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`BC " " &' &>R $=Ra BC( 1 $38 &83 " $72cb B2 R &A ( &$ =2\ $ OI "#bb5b " " &' &>$?H =:2 $ 3 " 7!$A & & " &$A d4 Categories and Subject Descriptors e 4 f 4 fg hiljuklam+no=p@kbi]qdo"kblcnrbs(nbigt:us7olp@s7vnwqxzygtu?w$ 38 &$A {7 = N 29 X "A #}~_ 'ƒ ` B =ƒ ˆT4 74 Š9g ZkdŒ Hm+si_o!niGt Ž s7 do6 9lCkdŒAs = =pwilrbxzy: >$ 3 "OB C &$A }.c C & Bš General Terms G?W$ 38 œb 9 & /œ D OI " &3 &$ Keywords *-,/.10Hœ9žŸž žjœd*-,/.10c ) & œl*-,/.10c ) & J &' &œ $38 &N$A3 ; & BC $ +*-,/.10+ )7 &' "œit?w$ 38CP &$ % X "A 1. INTRODUCTION J*-,/.10J )7 5 &' <&M>?W " &$A - VA& 85E " F -c &&'8$?*-,/.10 2$ 3 ( ) =2\"$ 2 6 $c OI "#bbsb " " &' &X$?B " <2$ 3 4H{7 " &' & ; 2c $:&3O $C - )7& 1$?9*,/.Z0 2$ 3 4 K! S & )N' "!= ; S =2N $> & V " "A 7 O <g 7œ7 xzœ #FJ$A % & == NC<Y> & &UFJ$?V{7$A " :! &&?@$ Q Permission to make digital or hard copies of part or all of this work or personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. WIDM 2001, Atlanta, GA, USA ACM /01/11...$12.00 R!$ 29& c ª«7 Jb 2>"$A 2 ; N = =2 9$A 92 " &O P $ g fcxzœ/r $ 2> : b '5 & 9$?<*-,/.102$ 3 X"$A 2 ; 9$ 2 =2Z3$ >&3OI$ 7 B JR!$ 2S& Z X '<$?G 2$" 3 5g# CŠ=xz4 *-,/.10 )7& - &' &< 2J $ ; 9"$A3 ; & =28& 7 $- )P &?W " &$A -& % "D7E " Fc " -% ) =2 &&' $?N*,/.Z0 2 $ 3 4 K! 1' 2C 2ŸOO $A &- $ ; &2 +R &A =2 = A œ! $638 & #F\ ' &38 1 %&3OI$ $?` A " F+ ' &J 26 $: & \ $: ' &J1R! " O $OI$ &$A d $ 9 "' 38C =2Z&3OI$ " A4 7 & #F &A & 6R! &7 - $+ " &' &&62 &±- #8 B2 &3 $A 3&! )_4 $ $C =œ 5 & & " &F>$ ""H$A& $?`R! " $ 2 A2 $c% )7& :?W " &$A (OI "?W$ 3 R!$ 5 B 1 $ PzR! " =2J )7&?@ $ /4 T ] 8 R!$ )cr! ZOO && =2] J $A38C 83 " $726?W$ $3 ; & 3( # &O & > " & d'f ' 3<2 ; 21& 6g# "x/ $ O $ ; & 3²$?H $A38C &= & #FJ$A3 ; & & *-,/.10 )7& &'P &4VK! ` " &' &S `$3 ; & =2-& Z9R &A =28= " 9 B2 \ $38 &83 " $726&( =26 $:&?@ " 8$AO &38MR! "?@ $3³ & & -274 ` = &Q[O & &$A 8 & BC &$A M S =2( $9 $=RŸ 38 7 & #F R! " N>3 # &Ṕ &' & )7 >?W " &$ R<# -& 7 # A #F $ "R &A = & =2 $ %OI?W$ 38 J2 2 &$ \ P OI "/ $`< $A Ṕ R &A =2µz &R &A L =E & #F5 "L $5 4 A /3 # &P " &' &M )7 `?@ " &$A /4L ] M & $> M = " &$ A #P BC &$A G $X $=R] V ( $A38C & #FR &A =2$A OI?W$ 3 $A PzR &A =2Z3( # #Ṕ ' &> )7&?@ " &$A /4 $A & & " &$ 9$?S*-,/.10]2 $ 3 SR<# 2#^_ " X " " &'P & - =2+ $Z $=R¹ BC5 &A$ & 3ºbB B2 >R! " 9#P &$ =2 $ OI #bbx " &' "`$?L Z$ & "" &$A /4 K! > &A$P # 3²&< & = & >R! &7 S?Q $A3² 92$ 3 S$A & & " &$ /4 { "" &$A Š]O J =2 R!$ )I4³{7 " &$A f\2 ; "1 &$ # 3» =2( $5b B2( <R &A M?@$ $A3 ; & & X < &'P &4\{7 " &$A \¼+2 "O&" ( # $?X 8 "D OI " &3 B2 { "" &$A 1½5 $=R<<NO $ ; "3a& X &A$ & 3² 2 $NbB 2 R! " 4 K! +38& "$A ; &$ 1$?N " 7ZOBOI " 1 +O P O &&=C $ Ÿ$?X 1 $38 &13 " $726?W$ $A3 ; & & :3 # &O & " & 'F ' 3H2 " " ; =2& 1g# "x $X!O $ ; & 3¾$?_ $A38C P &= & #F($A3 ; & & 9*-,/.10 )7& X ' &œ! "A &$A ($? S3 $72(R<# -R! ; 25 B2( `2 " $ $?d> B=RŸ& - 61

2 &A$ # 3»R<&83$ &AC =2# 3$72 #bb=c $ /œ7 #F ; & 2 &$OI =2d4 2. RELATED WORK TU g ŠCx!%' Fc $% $38 &= #Fc$A3 ; & 8*,/.10\ )7& &' &-&2 " ; =2_4]K! *-,/.10 )7& &' &-C "$A3 ; & =2& 8>R &A =2-3À B29A " " &` &A$ # 3a&V =2 $bb 28 XR! " 4 K! >R! " < 9$ ' =2J $ ; >& "P " ` J 9 A g# 44& =½Cxz4 K! 8 5R $ )]2 #^_ " 5?@ $A3º & g ŠCx!& ] NR! " &= $AO 3&Á=C &$A ' "F $9bB B2N! =R &A 4VÂMF & ( IR! &7 S& ' =A2J$?G& " S& Z ` A -g# A4&4& C½=x/R : "D O &$ (R<2 " X $?VOI$A ; & &# ">?W$ >$3 ; & &' &4 3. AUTOMATICALLY COMBINING HTML K!&! " &$A RANKING ; & " F2 " HEURISTICS ; X $38 &X3 $72-2 $ b B2Z 5R! &A X$?V3 & #Ṕ " &' &9 )7& -?@ " &$A 4`Ã$ > 2 "& & =2%2 " &O &$ % "?W " < $%g# x 4 Ä`Å &M <3 # #Ṕ &'! )7& 5?W " &$ -R<&&V $ ; <$OP &3&Á =2_4 Ä Å µçæ È'É 5O $C 2 5 & & 8 ' &38 $? 2 $ 3 " 79É%?W$ (E F ÆZ ZR &A Ê1Ë̵zÊÍÈ ÊÎÈ"ÏÏÏdÈ ÊCÐB 4 Ñ X & "V$? Ä Å µçæ7è É G3O #F S3( # #Ṕ ' &! )P & -?W " &$A : ' &38C ` `ÉJ` &&) #F1 & < $- NE " F Æ7ˆ 38 & / & <3O #F B`É&< & ` " "A 7=4 K! $H&> $b B2% & X$? Ê % B Ä Å ; '> )7X 2 $ 3 " 7 9?@$ % "$?`E "4%K! J $ &$A 6$?8Ò ; "'( )P & AÓ&JR<# OI ""8 $\6 " Z OI #b =2 $ 2 " & $C " 8 2 $ 3 " 7 9?@$ ( =\E " F4 Ä Å N " '?W & &F6 )A =2+ 2 $ 3 " 7 /?W$ ME FNÆ`R< (!$ 2 " & 9&3O && =2 ; F5! #P <$? Ä Å $ OI$ B21 $ 5$ 2 " & - OI "#bb =2 ; F 5 " =4 K! - N OI #bb =2+$ 2 " & %&9?W$ 38 &&Á =2 ; F: ; & BC F: "P C $ Ô<Õ12 "b =2 ; F] ]$ c 2\Ö $ g# =fxz4 Ã$ 2$ 3 É6 2]É!?@ $A3Ø J$ & $ Ÿ$?92 $ 3 " 7 Ù1y8É Ô Õ É `Ú 5 " <O "?W >28 $2dÛ&4 Ä Å BS " '?W & #F8 ) =2 92 $ 3 " 7 V?W$ `E7 " F8Æ5R< >$ 2 " & (&3O && =2 ; F > & $? Ä Å $ " OI$A B2 S $ O /$ 2 " & 1Ô Õ 4VK! 5$AO 3&Á=C &$A %3 " $72J &' &= #F 1 c O +$?(OBC 3 " 1 )7& Ê BC1?@$ 1OB# S$?G2$ 3 É B28É d; "$ ( $ X2$ 3 "$A & & " &$A +Ù1y Ä Å µçæ7è É Ô Ä Å µçæ7è É R< A " <ÉÔ<Õ`É 4 6 %$AO &3Á" :6" # " &$A ŸR<&Ÿ3 = $=RÜR! " < 1$ P 2 " & %&3O& =2 ; F Ä Å $ OI$A 25 $Z &$ Ô<ÕA48K! & $ ]&2 " & =2:?@ $3ÞÝ> 38 /Û N G$A& && BC &$A ]3 =CP Xg ½=x œs' &' &= ' &38 V$?7 H )>$ &$A ; "UR! UR!$8 ; "45K! " # " &$A +&92 "bb =2%& MEB4G NR< (ÉBœ_É C 2$ 3!?@ $A3³ 5$A & & " &$A +Ù1œÆ&>E " F8?@ $A3³ "$A & & " &$A +ßà 21Ê&S 9 X$?HR! &7 4 á µ Ä Å VËØ ã ß ãä Õåæ çéècê_ë è"ì ÄXÅ µçæ7è É ç èêiëèìiã Ä Å µçæ7è É ÄXÅ µçæ7è Ä Å µçæ7è É ã K! ( & $ á &9 c= A œ_$a " X E7 " & >& +ß-œI$? µ' = )38 ; " R Ô<Õ1 2 Ä Å?W$ %2 $ 3 ( Ù14 í $ c %R< Ä Å OI "?@ " #F $ 2 " 1 62$ 3 JR<# OI : $ Ô<ÕAœ> " $ : 22 $3& B $ :$?- MEB45 J =E & & =œ & 8 8 3Þ$?< Z2#^_ " ÄXÅ µçæ È'É Ä Å µçæ7è É N& E7 &A " 7N $% J 3î$?< J ; $A & JA& 8$? 2#^_ " " 4 TU ] &= Aœ - &$ J A4 26 8" # " &$A )A $ # (3 &3 3º & JP A4 746 é Ä Å &($A3O #F 2& $ 2 " =2_œB N 7 3 $ `&< N A & N$? (2 $3& BP $ =œ 5 &$8&XP A4 œd B2Z N" # " &$A &>38D &3&Á =2%C( 4 4 K! $M&5 $%3& &3&Á ( " # " &$ /4ZÃG&A % O $C72 N 38 &d "D3O >$?G 5 A& B &$ %$?H & $ /4 3.1 Numerical Optimization Method { & á µ Ä Å >N3$' &F+2 #^_ " ; & R<# + OI "N $%Ê7œG F 7 3 ; " S$?G' B " &=d$ao 3&Á=C &$A %3 " $72!R< 38)A - 8$?S 2& = ; =2 g# A x 4%T c " 7 R!$ )R! 5 2J > G$A)Ṕ ` ; & " 5&3O & 3 &$ J$?G >$A P ï C A2 " 7`3 " $72d4 K!$ 1#<&`3$' #FJ2#^_ " ; œ á µ Ä Å BS" # doi$a& R<# \Á " $+2 " & & A46ð> J & &=SOI$A& $" R< Ä Å &A J 3 )7& A &?W$ 8&!É ñ Ù14]K!(& J "D7 3 <$ B2# &$A Z 2J&!A " F&?Q =E =4 3$ XO P & N" # &=VOI$A& N$ NR< Ä Å µçæ È'É >Ë Ä Å µçæ È œl5 2 & $? ã òhã ò Ëa ZN =E # =2_48T + &N= AœLR! 82 P bb Nó ã òhã ô ó ò Ë Ï 8?@$ ò Ëõ ˆ_ &XB` N "^_ 9$??@$ & Ä Å µçæ7è É $ ; 5' &" #FZ =C " ` B Ä Å µçæ7è É!R< 1ÉÔ<Õ<É 4 4. EXPERIMENTS K! 5 & " Í ; =21& "?Ç 5 $- 93( # #Ṕ ' &9 )7& 'F ' 3 =25& 5 " 7L "D OI " &3 _= ; = =2NC!g Cxz4 4.1 Implemented HTML Ranking Heuristics K! &3O & 3 " 7 2X " &' &L 2 "D =2`?W$ 38CG$?I*-,/.10 2$" 3 4ZK! & B2 "D & %O $ " = "& 7 " =2+ 2 "D $ 7& & \R!$ 2 $" %& é c2#^_ " ZbB 2Z$? *-,/.10 2$" 3 5 B26" (1$ "" & #UFc O6 O P & - 57F OI " D < && )J$ "" & #UF ; R! " % (*-,/.10 2$" 3 5µzÃG&4BŠA 4 ' $AO &&'5&> =2% $8 "3$A 5$A33$ %R!$ 2 X 9= N $ 2& " &3& B NOI$CR " =48K! -' $AO] &&'$A 5$A33$ +R $ 2 & ' B2 2é2 $ 3 +µç A4 4 œ e ²$ %K e M ZJR! &N $33$A :R!$ 29& ]*,/.10\2$" 3 µ e ð M Ý9 SœI M $ < 4 ' "33 9$ # 3à& =2N $> =2 R $ 2 V $9' "3Sg& xz4 ÃG& B #FJ 5' 3<C 5' $ =2Z 1 7 =2J& 2 "D Ng ¼xz Implemented Field Heuristics ÃG& 2 &' &1 )*-,/.10¹2$ 3 %"$ 2 Ÿ $\ &3&QC # Fé$? E " F 2 : "D71& ] OI "&b+b 2 $? *-,/.1062$" 3 4H 9#^_ " " 7< &3& # FZ3 = <B= ; 2 $ & BC X X &3& # F ; "UR! " 1E "S 2 D =4GT 5" < "D OI " &3!R! 5 N $ 38 &&Á =21& " `O $72 " R<# %T 9Ã]' B2& =2J& ]g öxz4 ] &3O & 3 =2:,G Wøz ' & B> X N "D79& 2 ` ª ùªaú 7 5b 2$?L*-,/.10%2$" 3 œa%,i ],I ûøh &' BC> X 5b '9Š A -R $ 2X$?S*,/.Z0]2$ 3 œbz*> š 7øU üé,_ ûø( &' % - J "D78& 2 1ýBþ: 2\ý ÿ Í Ody [[ ï C 4 /4 $A3J[CO $72 " [C " 7 62

3 É Í È É Î Ô<Õ É! =ƒ" 8 ø ZÍ Î ÆAÍ ÉBÍ 4 4 ½ ÆAÍ É Î 4 4 ö ÆAÍ É 4 A4 á µ Ä Å Ë Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å Å p@rb LlCs "!` /nbm$#hw@skbj o&%/sjs7v nbww /no=p@kbi]kbj o&%ls á ŒAlp@os7lp@kIij kblnkiils('d Ls7l )+*-,(./ÆAÍ&0niGt21JtLkdŒ Hmcs i_o= 3*/ 4./ÉBÍ"È É ÎÈ É 0+5 Ž %Ls6 G s7l6#glcs7jus7l JtLkdŒ Hmcs i_ojé Í nigt É Î okÿtlkdœ Hm+si_o8É jukbl7'/ Ls7l ) Æ Í 5 Ž %Ls+lni98dpWiLr j GiLŒAo=p@kIipW JŒAkIi-:HrB LlCst<;p@o&% o ;k=%ls LlpW o=p@œ 3*>ZÍ5nBiLt?Î@*A;B%LkI s:lcnbi98dpwilrb -nlcs+ &%LkC;-i pwi od%ls o&%gp@lt nbiltÿj ki LlCo&%éŒAkIw@ Hm6iG kbj<o&%ls oncehw@sf5 b 2> B2%& Q2 (F OI " "D7` && )7 Î B2: $GX W!,_ ûø< &' & ` "X &d 9 "D7< :*,/.Z062$ Implemented Links Heuristics K!! && )7H &' "H S` O/œ" =C =22 & < M 2 "D & OB Aœ O & Z& )]$A 7# F ; R! " Ÿ& 2 "D =2 2 $ 3 " 7 5µzÃG& 4IŠ K/$$3O < X &3C &UF8$?G2$" 3 MÉ $-E " FÆ5 H ZµJI +0 W 7 = > &' &- " 9?@ $3 && )75$ "P &7# F OŸ &! J2$ 3 (OI$& 7 2 ; F µw BC-OI$A& $ 2 $ 3 " 7É+ 26 " 5 J= " Z & $?< KGX W X,_ ûø &' &9?W$ 9E " F8Æ- B2Z %$?H 52$" 3 5µzÃG&4BŠA Multi-Heuristic Ranking Function TU 1 5?@$A & &$CR<& Z "D OI " &3 SR! N & =2Z NOI "?W$ 38 " $?H 53( # #PU &' &> )7&?@ $ :& & ' =2%& :ÃG&4Bf 4 K! % & BC =2 )7&?W " &$A " c & A & % & " "' 38C 8$?X2$ 3 É+?@$ E " F6Æ1 & %R &A -Ê ËµzÊ Í È Ï"Ï=Ï/ÈLÊ 41T ("$A3 ; & 5& \ZR &A =2= " A &' & 2 " ; =21& {7 " &$A 1¼4& A4& 2%{7 " &$A %¼ 4& A4 Š K! S?W$A & Experiment &$=R<& "D OI " &3 `2 & =2 $5 Design & S ; P b 5$? & J $38 &3 " & 3?W$ 5b B2 JR &A $? 3 & #Ṕ " &' &> ) & (?W " &$ 4 HD OI " &3 1µ { A4d¼ 4 ¼ >$A3O 9 ( &Q[O "& $ OI " P?@$ 38 \$?J )7&?@ " &$A ¾ é& 7 # A #Fõ$ "=œ 38 7 B & #FJ & " =2JR! &A SR<# :( )7& (?@ " &$A % - $ R &A & ]µz &VR &A N =E B & #F+ "5 $c 4 4JK! "D OI " &3 $=R<X BC`= N $ 2 ; 9)A 1R< " : & " & R! " `?@$ 3( # #Ṕ ' &> )7&?@ " &$A 4 HD OI " &3 NŠ µ { A4d¼ 4 ½ >$A3O 9 ( &Q[O "& $ OI " P?@$ 38 8$?`Z3 # #Ṕ &' - )7& 1?@ " &$A ] $P 38C &= & #Fõ " "" =2õR! " R<# ¹Ÿ3 # #Ṕ &' c )7&?@ " &$A & % $%R &A & 41TUO " ( 72 " $CR<& < $38 &= & #FJ & " =28R! &7 S J3O $C ` >OI "?@$ P 38 >$? 3 # &Ṕ &' &X )7&?@ $ 4 Î T 8*-,/.1087F OI " D G& ) VC ` " $72 =2(& $ AV$?B?@$ 3MLONIÏ&Ï&ÏBÔ?PQ ò PRL ô NZÔ54SK! e &&A =2:KL D e &' & S "PQ ò P ; "UR! " 1 SLTNIÏ&Ï&ÏÔ 2$L ô N8Ôé ] XRS =28 $(b B2R< " " S > $38 &5$ # 3³ " "" R! " ` &$ =21 $-OBC & XB " " &' &>$?G 9 & & $ O 4 Ã$ 8 D3O & Aœ &?52$ 3 & +A& Ÿ$ O 8 2 " #F%&& )A =2Z $- 2:2$ 3 œ " 1R! 5R!$ 2% "D OI " BC( J $38 &83 B & 3 R< & < \&A]R &A ( $ && )J ' &4 HDOI 3 " 7Hf(µ { "A4A¼ 4 ö G$A3O G R! "?@$A B2?@$ M2$P 3 " 7 H?Q $A3» V "F &$AOB =2NÂM # &=µ { "A4¼4 f74 = R<# R! " G?W$A B29?W$ V2$ 3 L& 5 V & & ` "H$? M$ O { & A & M `$$H! $ F9?Q $A3 Ö!$$5µ { "A4=¼4 f74 Š 4 HDOI 3 " 7d¼ µ { "A4 ¼4 A!$3OB "! >R &A S?W$A B2?W$ >2 $ 3 " 7 J & (!$?/ <$ O S{ & ` `$$`!C A$ F?@ $A3ÀÖ!$$ µ { "A4!¼ 4 f74 ŠA 8R<# :R! &A 8?W$ B2?W$ 12$" 3 8& $ O & &O 5 `$$>!C A$ "X?@ $3³Ö!$$1µ {7 A4¼4 f 4 fa 4 9 < $N &&3# &$A & $A! $?Q R! 9C # " <R! `$ 2 $ 38 2$ 3 >"$A & & " &$A 6 B2:R! (B2: $J &&3&9$A & BC &$A V $5 38 &B29 " 4HK! ` &3#C $ V BC $CRŸ &2# F $?N$A Z " # Z Z $A 2 $A #F ; +& " O " =2 & # / 7Q2 " A4 4.3 KL$X A & B V M3 " $729?W$ V $A38 &= Document Collections &&FNb B2& <R &A GR! 21 N$ & $ 5$?S*-,/.10]2 $ 3 4`ð> N$A&& " &$A $ 7& =2\2$" 3 5?@ $3 "F &$AO =2 +ÂV & B2 R $-$ & $ X$A & =2%2$" 3?Q $A3²Ö $$3UA4 9$ 3 H& - <$ & $ MB= ; 38 7 B & #F( $A OI =2 & $S= $ & 4VÃ$ L $ F9R V"$A ' " =2> "D7LE " & 2J?@$ < =1E7 " FR! 5 S 92 $ 3 " 7 $?G >=C A$ F% & S $ NE7 " F4 K! Z $A38C J3 " $72c?W$ bb 2& %R &A %µ {7 A4HfA - 2$" 3 (O "?@ " " Z &$ Ô<Õ8R< " ZÉ Ô<Õ1É R< " 2$" 3 VÉ(&MO "?@ " =2 $2$ 3 VÉ?W$ SE " F(Æ74VÃ$ V 52$" 3 X$A & & " &$A 5R! "' ; && 2cÉ:Ô<Õ5É R< P >É ; &$A A> $- $ F%?@$ 9R<:ÆR!9$ ' " =2 2ZÉ /; &$A ` $--2#^_ " <=C A$ F Encyclopaedia Britannica Ody [[CRSRSR54 ; # &=74 $A3 U" Ody [[CRSRSR54 F7$$4 $3 63

4 d a d Š f d 1 d 5 d 2 d 4 VXWZY\[]W-^C_ µçæ È É U Ë `bacaed h"i P Y\[]WZ^ _ µçæ7èé U Ë `bacaed d 3 Q ò P"µÇÆ ÈUÉBÍ `facagd Q ò P"µÇÆ ÈUÉ `facagd d 6 Q ò PµÇÆ7È É Î" `bacaed Q ò PµÇÆ7È É Q ò P"µÇÆ ÈUÉ p@ri LlCs$jZlkNkIiGiLs ŒAo=pQvLp@o ) rblcn #A%>*>m noo>pqn9rtsk%ls LlpW o=pwœ%nigtvufwyxzo>pjn9rtsk%ls LlpW opwœc5 ÄXÅ µçæ7è É Ë Ê Í [ P QµÇÆ7È'É Ê Î { QDPN_µÇÆ È'É Ê df} ~ d Q ò PµÇÆ7ÈUÉ ODD ÊÍ ÊÎ Ê D DD& Ê U [ tƒ Q ò PµÇÆ7È É Ê `facagd Q ò PµÇÆ7È'É Ê VXWZY\[]W-^C_ µçæ È'É ODD DD Ê U Ê Ê D DD& Ê h"i P Y []WZ^ _ µçæ7è É & Ê p@ri /ls$1z ¾ Gw@o=peˆ %Ls LlpW o=pwœ lcnbi98dpwilrju GiGŒo=p@kIié G s t p@i o&%ls Œ /llcs i_os Z# s7lpwmcs ido= 35 K! M"$ O d?q $A3 V "F &$AO =2 Q<ÂM # &=S$ & V = Af<2 $"P 3! $ OI =2Z $ (= $ & 4 " F-2$ 3 $A 9 ; & <$?d$a HR<# FOI "D7 && )79 $1 "QC =262 $ 3 " 7 > =C A$ F4JK!7 œ/ $ O G?@ $A3¾ V "F &$AOB =29ÂV & œa && )5 &' & $A Q2J & NC A 5R! &7`& 1 > ) &?W " &$A d4 >$ 3 9& 6 V "F &$AOB =2%ÂV & 1$A 61 8P 3$ M$?d "D7=4 K! "F & #F8' R<# J 8& $72 " &$A $ $O&Aœ7#?@$A & &$=R<SN2 "$O3 M 2 "F$A & B2 <R<# 8 && )7 $: C =2\ & & 4K!& O " -: &A #b= 2 #^_ " " " OI "N $1' B2C 2+R ; 2$" 3 > N & #F+$A & 6 38 &X3$A 7$?X "D &Á 8 # $ & & & LOBC O K/$ ; &26 "$ O ({ & J `$$! $ F]?Q $A3ØÖ!$$1R Single Root Category from Yahoo $38 &= &#F 2 $CR< &$A2 =2 f J2 $ 3 " 7 <?@ $3 Š ; Ṕ =C P "A$ & X 2 " z Š y&y X D X X 3 Š 4 Ã$ =6 ; Ṕ =C A$ FcR " = 26Z "D7E F ; F D " P & ) "F7R!$ 2S?@ $3Ü 5 ; PU $ FJ & & Aˆ N2 $ 3 S$? ; Ṕ =C A$ F 2 ; Ṕ = $ & %"$A & 2éR<# #+R! " \ "c+ & $ ]E7 " F»µÇ A4 4?@$ + =C "P $ F? XŠ Ÿy&y X t X XŠ Œ@ ŽCŠ@ Ÿy&yJ«@ tœ 3 +š R! Z" "P C =2 ce F«@ tœ 3 +š6 B2]R 1 "- 12 $ 3 " 7 N?@ $3 Z $ FO XŠ y&y6 X D t X 3 \y&y1«@ Fš B2?Q $A3 Š y&yt X D X X 3 XŠ y&y\«@ Fšéy&y 3 tœ3š «@ tœ 3 +š8< " "A 7< $ 5E " F 4 K! $ O NRSN?@ " OB # &$A =26& $:1 & : 2] "A &$A 6 ; =4JK! - & % ; "N$ 7& =2\ ¼ J2 $"P 3 < 2c CŠE " & ` B2Z 5 A & B &$ : ; >$ & =2 = A -2 $ 3 < B2+ =½E " & K! ($ O Multiple # O Root & `$$!C A$ "N?Q $A3 Categories from Yahoo Ö!$$J$A & fa A 52$ 3 V $A OI =2& $N 9= $ & 4 Ã$ M ==C A$ F R! 1" = 2 + D E7 " F ; F\ "D7 c)a "F7R!$ 2 -?@ $3 =C A$ F1 # & ( B21 N2 $ 3 " 7 S$?H 5=C A$ F: & S $ NE7 " F4 9$ 3 9& + -O " &$ 5$ O ; "$ J $Z $A3O " & :2$38& /œ $C " &3& $O&8 2 :+$A33$ ï C A$ 6R< " 2$ 3 9& c N$ O ; &$A Z $ 2#^_ " " 7S $O&5C =œ$c " `2#^_ " " 7 $AO&` B2Z 52#^_ " " 7 $= ; QC F4 4.4 Experiment 1: Manual Weights Y> & ( 92$ 3!& Z > A & B &$ % ; "<$?G >$ O { & A & 9 `$$`!C A$ FJ?Q $A3aÖ $$1µ {7 A47¼4 f74 Š R! >"$A3OBC =2 M = &Q[O & &$A JOI "?W$ 38 S$?B S3 & #Ṕ " &' &M )P &?W " &$ é & & ' C =2é& ÃG 4<f] & 38 7 B & #FŸ & " =2 R! " " N $9R! " 8µz &BR! &7 M =E B #F M $ A4 A 4 Ã$! `38 7 B & &F- & " =2R! &7!R > " `&A '!R! " µ ½74 A Z $ ]K!# & ] &' ; = cr $ 2 : # & ]$? *-,/.10%2$ 3 H B2( $ ; <A$$72$!2 " &O $ 4 P $ 9$?VR! ; OA "9?@ =E " 7 #F: " "A 79) "F7R!$ 2>& 3 ":bb 2\ $cr : &A =2Ÿ 1 D &A " R! " µç¼4 ( $ - ' &A4M ] 5 & =2%-& " <R! "X?@$ ` NK!#P & &' ; "= \*,/.10 2$ 3 > - # & -bb "Q2+& 263$ -?Q =E #Fc 6 3 "Zb 2] 2 ; = 3 "5bB 2J $A3 " &3 S$ & S " /)A "F7R!$ 2 S $S =2 $( X $O&9$?/ >2$ 3 $3O $C X X " & _$?/ 2$" 3 ; FJ = % A& "µwr ; O33& 4 ýiþ-$ 5ý ÿjb 25$ 5 ( "D7N& +7F OI " D > & )75$A & c&a P &&A =2ZR $ 2S X 5 B & #FJ O " 7C & 9$?H 9$ 7 " 7 $?( 2 $ 3 " 7=4³ 6 ] =2 6 "D7%R! "\µzf 4 Z $ 64

5 Uniform vs. Manual Weights Uniform Weights Manual Weights Automatic vs. Uniform Weights Automatic Weights Uniform Weights Precision Precision Recall LlCsž y us ŒAnBw@w]Ÿ 9lCs ŒpW =p@kii ŒAk_m$#LnlpW kii E s7o;s7si n mcnbid LnwWw ) ;(s p@r+%dos t nbigt n ilkiizˆ;(s p@r+%dos t m Gw@opgˆ %/s /lp@ o=pwœ:lcnbi98dpwilr]ju GiGŒo=p@kIi> Recall p@ri LlCs? Z+us ŒAnBwWw Ÿ 9lCsŒApW =p@kiiàœak_m$#lnlpw kii E s7o;s7si nbi nb /ok_mcno=pwœanwww ) ;s p@rf%_os tànigtanilkii-ˆ;s p@rf%_os t²m Gw@o=peˆ %Ls LlpW o=p@œ lcni98/p@ilr]ju GiGŒAo=pQkIi>5 e &A &&A =2 KL D > &' 4X 6 ) =21 e &A &&A =2 K/ "D7G " &' &M &$=R! " L B 9 MO 7&$A _ R $X &' & ; = *-,/.10 2$ 3 >?@ =E &F+$ & 6 && )7N $2# " #F "P C =2 $ N $O&$?V 2$ 3 =œi2 " & 3 " 7X && )7X?@$ D3O & AœM 2) "F7R!$ 2- "D7 " =2]?@ $3î " 1 && )7(R<& & ; ; A21"$A `2 O $ 4 6 ( N8R &A5$?> A4?W$ 9 ($ 9¼J ' &µ & KL "D7=œ K/$AO:KL D =œt Ñ & )7œð> Ñ & )7 4 K! & H$? M = " &$ $A3O & $A!& & & ' 2 & :ÃG& 4B¼4 ZpW =Œ G = =pqkii>(ã$ 9 &3$A'9 " FZ = & & N O " &$ c$? (38 7 B & #F1R &A =2% )7?W " &$A &>R!$ ( % BC $?N : $ PzR! " =2 $ " OBC =4¹K!Z "D OI " &3 8 $=R< >= 3 ' ; N) " %R< :R! " )7& 8 &' & ; "= (R &A & ; =21$ %& # &$A %$ 2% & =A2J $8OI " P?@$ 38 N2 2 &$ % OI "< $ 9 5$?H $R &A & Experiment 2: Automatic Weights 6 S =22$ 3 H -! & & 5 ; M$?I S$ O!{7 P & > `$$`!C A$ F?@ $A3ÀÖ!$$8µ { "A4¼4 f74 Š M $ $38 &= #F b B2c R! &A $?< 83( # #PU &' &- )7 %?W " &$A & #P & ' =26& cãg&4hf748k! & " =2cR &A N $=R< 6& c # 2Z$ 3 1$?VKG ; - 4 YX & 92$" 3!& 1 > & BC &$A % ; "<$?G 9"$ O {7& A & 9 `$$<! $ FJ?@ $A3»Ö!$$Jµ { A47¼ 4 f 4 ŠA R! X$A3O =2 ` "= &Q[O & &$A %OI "?@$ 38 X$?d < )7& 5?@ $ 8 'P & ( $38 &= & #F-?@$A 2R! &7 VR<# Z9 )7& 9?W " &$ 'P & ( $R &A & 4VÃG& 4B½5 $=R< ` " # S$?d ` & BC $ /4 ZpW =Œ G = =pqkii> Ã$ 8$=RÜ = & > & : $A38 &1R &A OI?W$ 3 ; " " Z B é + #?W$ 3 R &A 4 { é " 1 B #F $$) $A #F J : $AO Š ] )A =2é2$ 3 4 K! 92 $ 3 " 7 $ OI$A 28 $5 ` &$=R &I " &$A J$?_ "= &Q[O & &$A : A4VK! "?W$ > > $38 &XR &A S&3-P O $C - -O & &$A ]?@$ 2$ 3 5$A33$ #F "D3& 2 ; F % & 5 4 K! ]2 $ 3 J 2 E7 " & 1 =2 $bb B2 :R! &A :C 2 #^_ " 8?@ $A3 2$ 3 8 B2 E7 " & J =2 & % "P *N W øç zƒ > B C = ~ W # K!# & 74 Š Š 4 Š¼Š 4 f ö " 4 A ö 4 faf¼ KL$O:KL "D7 74& =faf 4 A A½ e & &&A =2%KL D & /KL "D7 74 ŠA½A½ 4 ¼fA½ T Ñ & )7 74 ½A½¼ 4 ŠC¼ ð> Ñ & )7 4 ¼Af Ž n EGw@s +ª Z /ok_mcno=pwœanwww )¹j ki GiGt«;s p@rf%_o= %jukl6tgpe s7lcs ido tlkdœ Hm+si_o ŒAkIwWwQsŒo=p@kIiG 35 kkiww Hmci &%Lkt; o&%lsõilnim+s kbjjo&%ls %Ls LlpW opwœ nbigtaœakiww HmciG jz*b1 nbilt± ¹ &%Lkt; o&%/s ;spqrf%do j kbl!>ilœ3)lœaw@k+#gnstlp@n±²lp@onbiligpwœań ³ qds ŒC5S y5g1z5 Cµ * n+%/kdk6q/p@ilriw@s:uk_kbobkno"s rkbl )O³ qds ŒC5- y5g1z5gj+µ9nigt n+%/kdk ¾ GwQo=p #Hw@scuk_kBoKkno"s rkblp@s 4³ qds ŒC5\ y5g1z5g1+µnlcs D#Vs ŒAop@vIs w )+5 =Q[CO & &$A & &$A d4 K! " "?@$ Aœ X " # S?@ $A3ÜÃG& 4I½ & B2 < BV ` $A38C &X3 " $72&! ; & ` $5 " ""!R! " BCL #G& NOI "?W$ 38 " M&3O $C "3 B?W$ HE7 " & L $L$A P 2 " 2Ÿ2 & 8 & & 6 &$A d4ÿk!&-b " " &' &:$? ` $A38C &`3 $72( $5 " &Á" ` $N R E " B22$P 3 " 7 >5R<38) "9 $A38C &= & #F6R &A =2c )7&?W " &$ ($?B " & B M $A Ṕ R &A =2N$A " OBC =4 4.6 Experiment 3: Encyclopaedia Britannica ] =2> 2 $ 3 I?@ $3õ F"$OB =2<ÂM # &=Nµ { A4 versus Yahoo ¼4 f74 = ( B2+?Q $A3º ( & & 1 "$?S $ O ({ & & X$$! "A$ FJ?@ $3²Ö!$$%µ {7 A4 ¼4 f74 Š S $bb 28 >R! &7 <$?G 3 # &Ṕ &' &- ) & %?W " &$A & && ' 2\& \ÃG&4Hf 4+K! R! " G?W$A B25?W$ V2$ 3 /?@ $3¾ "F &$OB 2>ÂM # &= 2?W$ <2$ 3 H?@ $A3àÖ $$C X $CR< 8& - < "$A B28 B2 # 2J$A & 3 S$?VKG ; & - 9 OI "" & #F4 1p@ =Œ G = =p@kii Ã$ 2 $ 3 _?@ $3¾ "F &$AO =2 XÂM # &= J && )7 &' &œ<ð> Ñ & )7- B2T Ñ )7œM " & =2] & '8R! " œ`r< " =J?@$ 12$ 3 -?@ $A3 Ö $$6 F "A =2 &$CRÌR! &7 4 Z $ =2 & { "A4S¼4 f74 œ52 $ 3?@ $3Ø V "F &$AO =2 Q:ÂV & 1$A ]Z ; $?S$ 7 " 7 R<# :FOI "D7<& ) < $- 2:2$ 3 S % 5 3 N=C P 65

6 "A$ F49K!&93 = < BC9&& )7> &' &œ ; F%$ 2 " & J "$A N$?< && ) 262$" 3 œ_r<&v " ca& B ; &?W$ 38P &$ c?w$ 5 )7& JO $" N 2dœ_ 7 œ_ "F% $A 2 " & C A %R! " 4éð> Z$ " 8 2 Aœ!2$ 3 (?@ $3 Ö $$ C ZOI$$ #F\& ) =26 $:$ " 2 $ 3 " 7 N& 2 JÖ $$+ $: && ) ' &œ $A #F"$A 2 " && )7M $N$ "!2$ 3 & Q2 3 ($ O œ_r<& & ; ($?M& 5 &O?W$ 9 )7& O $ 4 R! Z3 &$A 2\& { $ Ÿ¼ 4 f 4& Aœ<2 $ 3 " 7?@ $3 V "F7P "$OB =25ÂM # &=5C S' " =2(& ( S 3 R!F- # E7 &A " 7J& %OBOI " J " &$A é$?5 % "F &$AOI =2 ˆ9 "F B #F' VR<& 8 & 7 $72 " &$ - $N> $AO&Aœ&V?W$&$=R<S52 "P A &$AO3 " 7> 21 "F1$A & B2 R<# & )7X $8 =2 && 4 K!&N "O N ]&3OI$ N2 #^_ " " -$A3O =2 $1' P 2 2 R! ; 2$ 3 > BC5 &#F+ 338 &Á # 5"$A & : N& # HO O4>K!&92 #^_ " " (&X B " 2 & % R &A 8?W$A B2 ; F\ $A38C &:3 " $72_4¾Ã$ Z2$ 3?Q $A3 Ö $$œvr< " 8 "D7-& \ J& # <OBC O- 338CP &Á : %$A 8$?5 :2 $ 3 =œm :KL$OéKL "D78 &' & " & =2 `&A '!R &A & œ7r< " =M?W$ `2 $ 3 " 7?@ $3 F"$OB =25ÂM # &=7œR< "!!& # OB OV P &&F1$A 1 $72 " $ F138C " Çœ NKL$AO:K/ "D7S & =21 &$=R R! &A=4 >$ 3 5?@ $3Þ V "F &$AOB =2 ÂM # &= 2$: $($A 3 b 2ˆ 7 œ` c $38 &63 $72é & =2 Á $ R &A` $( &' 4 K! ZÁ" " $:R! &A($?< e &&A =2\KL "D7 " &' &Z& ; $ "$ OI$ N O " SO $ ; "3a$?/ > $38 &`3 " $72- BC R<& & ; N2 & =2Z :{ " &$ :½ Experiment 4: Single versus Multiple Root 6 5 =2J N2$" 3!?@ $3³ 9 & "X$?H 5"$ O Categories from Yahoo {7& A& 9 `$$X!C A$ F8?@ $A3»Ö!$$1µ {7 A47¼ 4 f74 ŠA S 28?Q $A3a "$ O S$? # &O& 5 X$$`! "A$ & <?@ $3²Ö!$$Jµ { 4¼ 4 f 4 f $%b B2c R! &A ($?S 83( # #PU &' &- )7 %?W " &$A & && ' C =2J& JÃG&4f 4VK! `R &A?@$A 2-?W$ <$ OI$ -{7 P & 5 X$$`! $ F1 2 & &O > X$$X! $ & X 9 $CR< & %"$A & 3 <f- 2Z¼-$?H ; & NKG ; & - A4 ZpW =Œ G = =pqkii> é " 2 $ 3 " 7 Z$C " 2 #^_ " 1 $O& # & >b 2S$?H *-,/.10+2$ 3 S ; " " <$ P " 7 2& " &3& BC $ V B -R< 82$" 3 $C " V =2- $OP &4 $ 2& &FœH J $38 &3 " $72] &A =2\:&A " R &AV $9 "5 B2( $9 <K!# < &' &?W$ V S"$ O # O & Z `$$-! $ & -?Q $A3ØÖ!$$% B 6?W$ J"$ O {7& A & 5 `$$>! "A$ FZ?@ $3ÜÖ $$Z4 8 $ 2 & é{ "A4!¼ 4 f74 f2$ 3 -?@ $A3 %$ O Z{ & A & `$$S! $ F8?@ $3ÀÖ $$N B >5$A33$ ï C A$A JR< " 2 $ 3 " 7 & - S"$ O # O& X `$$!! $ &?Q $A3àÖ!CP $$X 2 #^_ " LA$= ; F4GK! " "?@$ V O& N "D7L $A Q2 ; 6 ; " %$ :2& " &3& BC $ :& é +$ O # &O& `$$S! $ &!?Q $A3àÖ!$$5 B - <$ O S{7& A & ` X$$!C A$ F]?@ $3ÞÖ $$4%K!&(?@ = J ; =O =2 ; F N $A38 &53 " $72Z BC` &A =2 & " `R! &7` $ 9,_ ûø &' Z& \ Z"$ O # &O& Z X$$8! "A$ &?Q $A3 Ö $$ B & $ O N{7 A & `$$5! $ F?@ $3 Ö $$4 Ö $$>2$ H $ & " 2 V R!$>2$ 3 L?@ $3¾ M 3 # S& Z & A & -=C A$ Fdˆ/ 7 œ_=c A$ "?Q $A3 Ö $$JR<& & $A & 2$" 3 H?@ $3a2 &^_ M # 4M $ 2 5 BV S38 ï $ P # F6$?S 8F OI " "D7N && )7C Z& " && )7œ && )7 ; " R OBA <$?L X 3 9 # Aœ#S&S = $ B ; & 9 $( "D OI S BS2$ P 3 & Z & A & 9=C A$ FZ$?LÖ $$R<&& ; >OI$$ #FJ&& ) =2- $ $ " H2 $ 3 " 7 d& 9 V 3 =C A$ F4 K!7 œ= V38 ï $ #UF5$? S && )7?@ $3»52 $ 3 " 7 & -Ö $$> $N $!2 $ 3 & Ö $$5R<& &I$ ; "UR! J2 $ 3 & J2#^_ " M= $ & 4! "A$ & S& `$ O # &O& ` X$$<! "A$ & S?Q $A3àÖ!CP $$1$C " (2#^_ " 5 $O&4ZK!7 œg#n& &&) #F: (%2$P 3 " 7N& $ 8= "A$ FcR<&S && ) $ :2$" 3 & $ =C A$ F4cð> 6 8$ " ( Q2 Aœ =C A$ "-& ] $ O { & P A & J X$$!C A$ F]?@ $3ºÖ!$$:$C " 2 $O&( 26# &>O $ ; ; & N B>82$ 3 <?@ $A3 $A ( $ F%R<& &H& )Z $ :2$" 3 N& $ " = $ F4%K! " "?@$ AœM2 $ 3 5& N$ O 9{7 A & X$$N! "A$ F1?@ $A3ÜÖ $$8$ & :3$ && )7 $6$ " Z2$ 3 -& 1 3 %$ O 8 Ÿ $ O # &O& X$$N! "A$ & X?@ $A3 Ö!$$ 4>K!&X?W & " " =28& Z$ & 3 f( B2¼$?HKL ; & XR< " X XR! " & =25 $` & ) / &' "H M =C " G?W$ G $ O H{ & P A & X X$$<! "A$ F8?Q $A3àÖ!$$N B -?@$! X"$ O & &O `$$>! $ & `?@ $A3³Ö $$4 A& /œi (Á" " $R! &A5$? e &A&7 2+K/ "D7> &' && ; $ "$ OI$ 9 O M9O $ ; & 3à$?_ ` $A38C <3 " $72 BCSR<& ; 52& =21& { "" &$A ½4 5. PROBLEMS WITH THE ALGORITHM K! X FOR &$ # 3a?@$!b B2 9R! &7 $?/3 FINDING WEIGHTS# #Ṕ &' S )7&?W " &$ Nµ { 4BfA $AO &3&Á S 5 ; &# FZ$?L 9 )7 (?@ P &$A 1 $(38 Z 52$ 3 SO?W " 9 &$ 6Ô<ÕA4MK!&<& -O "& $ $A O=4SK! &A$ # 3 `$AO &3Á" - NO "#P &$A 8$?_ < )7& 5?W " &$ - OI "M $N `2$ 3 MO "?W P "QC &$A /4N ` =&H> $ 5&3OI$ X " " &' &-$? )7?W " &$A > BC>&9 $ ; " 8$A Q2 " =2 ; F1 $AO #P 3&Á= &$ : &A$ # 3%4 KL$XOO C M V$ =E " L$?$AO &3&Á& <O & &$A (R<# P $A $A 2 " & 9 "= & $A Q2 " M>$ & $ $?G A 52 $ 3 2c E " FJR< ½ 2$ 3 < N & < $- NE " F4 3 - R $ )7& : &' &œ e J B2 e Š74 e & `2$" 3 S& Z " OI$A 5 $ 5E F1 B2 e ŠN ½7 +2 $ 3 " 7 R< " +2$ 3 - )A =2 : $ é¼ & S $ 9E " Fœ2 $ 3 M )A =2%½ &`# & ` B2 2$" 3 8 ) =2 ½7 c&z & =4 %38CD&3( 3 $$ 2#P BC &$A & e +& "138D &3 3 O "& $ À 4 B2é &$=R = & < ô ½ 1 2 e Š& 9 &3$A'5OI?W "9O & &$A ]½ ô ½7 238D &3 3õ = &L A4 4VK! " "?@$ Aœ e ŠX BV$O &3&Á ; $ O "& $ % B2- = _OI "?@$ 3 ; "! B e ` B $AO 3&Á " O "& $ %R<& & N& 7& -&$=R =&Ç4 e ; F )7& 5 & S2 $ 3 " 7 V& " M B 8 $A Pz & $A OI?W " #F38C `2$ 3 O "?W < &$ +Ô<Õ R<& & e Š5 BS )7` $ Z & `2 $ 3 ;?W$ N & "P >$ 2$ "> $9OI "?@ " #F%38C ]Ô<Õ4>K!7 œb ; &#UF:$? 5 )7& -?W " &$ % $J38C Z N2$" 3 `O "?@ " P &$A JR<& ; >$O &3&Á =2R< e Š5&S $S =28& J X )7&?W " &$ /4cK! J$AO 3&Á=C &$A &A$ # 3 ; Fc$A &F]$A Q2 " & (O " &$ c$? N )7 J?@ " &$A +92& = 2 & Z ; P " ` " &' &A4 66

7 K!&5O $ ; & 3 = ; ( $A& =2 ; F:$3 ; & 8 $AO &3ÁP &$ " # " &$A 8>3 = S$?I SO "& $ $?I! )7& X?W "P &$ NR<# S3 = $? # / = &z4l ] V V " 7 #F92 "$O& %$AO &3Á &$A % & $ %R<# Z " 5 " &' "4 TU % 2 " " ; =2: "D OI " &3 µ {7 A4¼ < e &A&7 2:KL "D7 &' &5 & 21Á $-R! &A ; = N#SRS` 5 " `O "P " Z$?> &! 8 &' & B2dœH 7 œv J $38 &J3 " $72 3& 3&Á 2Z# SR! &A=4 6. SUMMARY $A38C &:3 " $72\?W$ J$3 ; & c "A >'F ' 3:g# "x R!XOO && =2J $ 9O $ ; & 3³$?H$A3 ; & & ( )7 &' & & $`3 # #Ṕ &' )7 `?@ " &$A /?W$ *-,/.1082$ 3 4 K! X3 $72RS =2 $5bB B2 SR! &A V?W$!3 # #Ṕ &' )7&?W " &$A S' " =2Z<R &A =21= A >$?G )P & ( &' &4M D OI " &3 V & N ] ; 25R! 92 " &$AOI =2 $ A & B 9 9OI "?@$ 38 5$?H 5 $A38C 53 $72d B #FX$A ' " 25 5& # & #F9$ "L "L$?7R! &A?@$ <N3 # &Ṕ &' &S )7& 5?@ $ /4H 6 X$3OBC =2 < "P &Q[O "& $ :OI "?W$ 38 9$?G J& 7 # A #F-R! &7 2Z " ] $A Ṕ R &A =2 3( # #Ṕ ' &% )7& 6?@ $ /4àK! :& P # A #F:R! &A =2?W " &$A coi "?W$ 3 =2:R!$ ( B $A P R &A =2"$A " O $CR<& > BC = S3( ' ; M) R< "$A3 ; & & *,/.10 )7& ( &' "4 YX & =Q[CO & &$A & BC $ JR! $=R! 2é 1 P $38 &= #FR &A =2\3 # #Ṕ &' 8 )7 +?@ " &$A \OI " P?@$ 3 ; " " J B $A PzR &A =2 3 # &Ṕ &' &: )7&?@ " &$A /4 $ & "" &$A Z$?*-,/.102 $ 3 " 7 -R<# 2#^_ " J " " P &' &R! " J =2+ $%bb B2+ -R! " (?W$ ( 83 # #Ṕ &' )7& 1?@ " &$A /4J ] $=R! =26 N?W$ ( \2$ 3 5$A #P & $ J < & " =2R! &7 VR! " `& &$ =2 $NOBC " P " " &' &>$?H =%"$A & & " &$A d4 O $ ; & 3 & \ 1 &A$ & 3 =2 $cb B2] ZR! &A -R! 2 " " 2% 21 $ &$A %&` #F ; & 2 "$OI =2d4 g öcxn 4 e 38 /4 J "D OI " &3 _' B27FJ$?G?W" $ 3OI$ <& %2 $ 3! )7& 4TU 4! =ƒ ü W ( 9ø@ GþL. ~ I º>I»XœO 5 = Aö&ÁB Af œd & œtu #Fœ_ = Aö74 g =x # / &' &5'F ' 3³ 2Z& 1 92 " ; =2 "D OI " &3 4 X 3 Ä½Å Å Æ Æ Æ ÇXš Š È\É] Cš tåtë& XÌ X XÌ Å X XÍ3 Š Cš3Å@ Ì Ž Î CŒ74 g CxÃÏ4 4 Ð5 & & ; " 4 $ &C & 9 $A <& %7F OI " && )A =2 7 # $ 3 =47T 7 S ' =ƒ ( 9ø@ "Ñ> W ø@ KG` A GþL.+š ~ W "ƒ" øu "GX Wø@ ( œoa " öaöa &Á7öA A 7œ/{ 1à & $œi! &#?W$ œzï F = A 74 g Cx Ñ 4 HA 4IK! 5O " )Z#C $ 1 )7 y ; & A& $ 2 ` $( >R ; 4T 7 S ' =ƒ ü W ( fg9~ I~ÓÒ Ô3Õ@ÖAG` A.6 øç W 9ø@ Gz8 zƒ ~I =ƒ" z ø b " fi & " - øç z ~Iƒ" Bƒ œ/ = A 4 g# = Cx 4 à 4B G$ " =4 1 &A$ # 3³?W$ > ±-DJ' OO& 4TU S 3 ¼$? AœOBA 5 =f Á =f œzïa #F+ = A 4 & ; & N 7 Ody [A[$OI /4 3( =C=4 "$A3J[2 &$OI " [2 $[OI$ " ' 3%4 3z4 g# A x5 ¾4 e 4 œbâx4 G4BÃG " FœB{_4 4K/ )$ & )7Fœ B2J õ4 K>4 Ø " & 4FÑ9 8 zƒ A F»` ƒ" 2¾H4I!3 ; 2 A Y> & &UFZ œ/ = A4 g# CŠ=x <4 & A & Aœ 4 Ñ &$CF2_œ B2 Ñ 4 4 >$CR A4 ébc<x( OI$AOOFJ3$A (R! ; O Ù%T 4! =ƒ ü W ÛÚ=ø@ I øu I øç z I A >ž1 &ü]žz zü :ž% DÜ ¾V D = Bƒ œboba faöa &Á7fA A 7œdÂV ; Aœ ' 7œ O &V A A 74 g# =fcx({_4 Ð-4 4 6$A - B28Ö4 Ö4 Ö $4+Ý> F?W$ 3( &$ %& & = < " & /3$72 &4T ßÞ7 I G 9ø@ bgz8 zƒ ~I =ƒ" ø f zi & øç z 7»` øç ¼ A œ$a & 3 >¼ 9$?zàœ OB `faf¼ Á7f¼ œh = A 4 7. REFERENCES g& xnâx4 K>4I &ÇœdÝ(4 ¾4B $ &Çœ_ 2Z N4 ¾4BÂM & "R54 $A38C >$A3 ; & BC $ 1$? 3 # &O & > ) 28 " & 'F ' 34 T 7 S ' =ƒ ü W ( 9ø@ ~A ƒ" z ¹I øu ø"º! 7I & " - øç z 6»< øç ¼ A œb > ; && /œtu "Q B2_œ/ A ¼ 4 g Š=x 4B & " =œ e 4 9 œi{i4 {_4 &3%œ B28 ¾4 4 R' 2 FJ$A Z & 7 3 _' "! $3O $C " & Ç4BTU 4! =ƒ ü W ½Ņø@ f < ¼ ø@ 6I > ¾V D = Bƒ (,I = A " Wø@ (G` øç À ƒ" z ¹I øu Iƒ œob ¼ ö Á¼ A 7œH = A 4 g fcx 2 & &$A :$?H =C PU " A& NR ; Ṕ OA 9 )7& 3 4 & ; & N< N{7 = % & 9 C JR! ; # 5 O/y [A[C = A& RS /4 $3J[C )I4 7 3%4 g ¼x9 ¾4 ÂX4Bà ) "< B2Z 4Â! Á=PzÖ 4¹I & - øç z»< øç ¼ ẽâ ǿ ~øç ƒ"øç - 4 H " "P e &ÇœL A AŠ74 g ½=x Ñ 4BÝ> 38 /47 é<&< $<R<`& 1' &' &4ITU,/ ~ǿ øç W øç zƒ" z œb$ 3 NŠö7œBOA "X 7 Á = œg = A 74 67