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- $BBg5,LO$J(B corpus $B$,EE;R2=$5$l$k$H(B,$B$=$N>pJs$H(B parser $B$r7k$SIU$1$F@:(B
$BEY$N$h$$(B parsing $B$r9T$&$3$H$,$G$-$k$H4|BT$5$l$k(B
- $B$9$Y$F$N(B courpus $B$,@5$7$$(B data $B$J$i$P(B viterbi algorithm $B$N7k2L$r(B
$B$=$N$^$^(B parser $B$KEO$;$P$h$$(B
- $B$7$+$7(B,$B$9$Y$F$N(B courpus $B$,@5$7$$(B data $B$O8B$i$J$$(B, $B$h$j:GE,$J2r$r(B
$B5a$a$kI,MW@-$,$"$k(B
- $B$H$J$k$H(B, viterbi algorithm $B$N$h$&$J:GBg(B category $B$N3d$jEv$F$r(B
$B$?$@$R$H$D$@$15a$a$k$h$&$J(B algorithm $B$G$O$J$/(B, context $B$r9MN8$7$F(B
$B3FC18l$KM=A[$5$l$k(B category $B$N3NN($r$9$Y$F5a$a$F(B, parser $B$KEO$7$?(B
$B$[$&$,$$$$$N$G$O$J$$$+(B?
$BF~NO(B context $B$N>r7o2<$G$NG$0U$NIJ;l(B,$BG$0U$NC18l0LCV$N=P8=3NN((B,
P(wt/Li|Input)
- context-independ $B$JC18l$N=P8=3NN((B Figure 7.13
- context $B$r9MN8$7$F(B ``The flies like flowers'' $B$NCf$G(B, ``The flies''
$B$N(B flies $B$,L>;l$G$"$k3NN($r5a$a$k(B.
- $BJ,;R(B
The/? flies/N $B$H$J$k9M$($&$k$9$Y$F$N3NN($NOB(B
The/ART flies/N (
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The/N flies/N (
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The/P flies/N (
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- $BJ,Jl(B
The/? flies/? $B$H$J$k9M$($&$k$9$Y$F3NN($NOB(B
The/? flies/V $B$H$$$&CM$b9MN8(B (
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$B$3$N(B context $B$G(B flies $B$,(B N $B$K$J$k3NN($O(B 0.9998
$B$3$N$h$&$J(B context $B$r9MN8$7$?3NN(CM$r8zN($h$/5a$a$k$K$O(B?
viterbi algorithm $B$K;w$?forward probability
-
$B$NC18lNs$,=P8=$7(B,$B$+$D(Bt $BHVL\$NC18l$,(B
category i $B$KB0$9$k3NN((B
- $B4pK\E*$K(B vitebi algorithm $B$HF1$8(B
$B$KJQ99(B (
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$B2DG=$JAH9g$o$;$N3NN($NOB(B
- SEQSUM$B$NCM$G@55,2=(B
Figure 7.14 $B;2>H(B
- Figure 7.15 viterbi algorithm $B$G(B
$B$KJQ99$7(B
$B$?>l9g$N(B score (
- Figure 7.16
$B$+$i5a$a$?3NN(CM(B
($BNc(B)
- backward probability
-
$B$NC18lNs$,=P8=$7(B,$B$+$D(Bt $BHVL\$NC18l$,(B
category i $B$KB0$9$k3NN((B
- forward probability $B$HF1$8(B, $B5a$a$k8~$-$,5U(B, $BJ8Kv$+$i;O$^$k(B
- lexical probabilites for word wt
- forward brobability, backword probability $B$rAH$_9g$o$;$k(B
1999-08-03