(Selective Ensemble)

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????? (Selective Ensemble)
???
http//cs.nju.edu.cn/people/zhouzh/ Email
zhouzh_at_nju.edu.cn
???????????????????
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????

• ??generalization
• ??????,??????????
• ??????????????????
• ????????????

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????
????(Ensemble Learning)?????????,?????(??????)????
???????
???????????????????? ????????????,??????? ??????
???????,????????
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????????
???20????????????? ????????? ???????????? ??????
??? ????????? ???????????? ??????,??????????????
L.K. Hansen P. Salamon, TPAMI90
????????????????????????,?????????????????,??????
T.G. Dietterich ????????????????T.G. Dietterich,
AIMag97
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???????
????????????????????Web???????????????????????????
???????
????????????,????????
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????????
????????????????,????????????

• ????????
• ?????????????,????????????
• ???????,????????????

?????????????????????
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?????
Many Could be Better Than All????????????,???????
????,????????????????? Z.-H. Zhou et al., AIJ02
????????????????(k)???
??
??
????,??????????????????
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GASEN(????????????????)
?????? ?????????,??????????????????,????????????,?
????????,????????????????????,?????????
????????????????,?????GASEN??
...
...
Z.-H. Zhou et al., AIJ02
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????
??????????Bagging?Boosting??,GASEN ??????(????)
??,????????????? (??19 (3.71/20)??36
(7.10/20.0))
Z.-H. Zhou et al.,
AIJ02
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Bias-Variance??
????????????, bias ?????????????????????? varianc
e ???????????????,??????????????
??????????
R. Kohavi W.H. Wolpert, ICML96
??????,Bagging????variance,?Boosting????bias
E. Bauer R. Kohavi, MLJ99 L. Breiman,
TechRep96
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????
??
??
??????,GASEN???bias?variance?????Bagging?Boosting
??????,GASEN???bias????Bagging,???variance????Boos
ting GASEN??????????????bias,????????variance
Z.-H. Zhou et al., AIJ02
bias
variance
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????????????????
??
??
?????
??
??????
???
??
??
??
Bill Gates ????????????????????,?????????IT??????
?????
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????
???????????????????????????(??????????)
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????????

• ??????????,?????????,?????????????????????
• ???????????????????,????????????????????????
• ???????????????????????,????????????????

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???(eigenface)??
??????????,????????????
??????????(PCA) PCA???????????????????????(???)???
???,????????????,?????????????????? ?????????(????
?????)????????(?????????????)???
?PCA?2?????1????,?????????,PCA?????????????,??????
????????????????????????????????????
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?????

• ?N1,?N2???P ?????N1N2????x
• ???? ,??y???m ????x???n
• ??W ??y ???????x?????(variance)
• W ???
• 1) ??????????
• 2) ??C ????????????
• 3) ??????? ,????????????
• 4) ?????m????? ??????W

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?????

• ????C ?????????????,???????
  ??????????
• m????

????????????,????????,???????
M. Turk A. Pentland, JCN91
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????(eigenfeature)??
??PCA????????????,???????
R. Brunelli T. Poggio, TPAMI93
A. Pentland et al., CVPR94
?????????????????????,?????????????
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??? vs. ????
?????????,??????????,??????
?????
???????
????????
A. Pentland et al., CVPR94
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??? vs. ????
?????,??????????? ??,?????????????????????,??????
???????
????????????,?????????
???????? ???????(????????) ???????????(??????
????)
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SEME(????????????)
???????????????????????,??,?????????????????,?????
????????? ???????????????????(????3431???????????
??295,120?),????????????????,????????????,????????
???????
?? ,????????

• ???????????
• ???????????(??????)

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SEME(????????????)

• ??k???????(??????,???gallery??,????probe??),??????
  N???(R1, R2, , RN.)????m?
• For i 1, 2, , N
• ?gallery??????,?Ri ??????????
• ????????????probe??,?????ri
• ?Ri?????ri??????
• S R1,A R2, , Rn,?? m ltlt n ltlt N
• For t 1, 2, , m-1
• ?A???????Ri,??Ri ??????,?S?????????????probe?????,
  ??ci
• ????????????ct???Rt
• ?Rt?A???????S?
• ???S?m?????????????????

X. Geng Z.-H. Zhou, unpub04
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????
FERET?????????
SEME?????
????????????
??????????????Rank????
X. Geng Z.-H. Zhou, unpub04
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SEME?????
SEME???(??)????,???????
?FERET????????????????????ORL(?)?BioID(?)?????????
??
X. Geng Z.-H. Zhou, unpub04
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???????
??????????????,??????????,?????????
??????????????????? ?????????????????
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