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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
수학을 1도 몰라도 알 수 있는 구글 번역과 알파고의 비밀
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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*주의�:��발표자는�기계학습과�수학을�1도�모릅니다.��전적으로�디자이너의�관점에서�쓰였으니�프로그래머�분들의�
양해를�미리�구합니다
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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사람은�복잡한�문제를�어떻게�그렇게�빠르고�효율적으로�처리할�수�있는가?�
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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인공신경망�:��사람의�신경망을�본딴�방법론�
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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기본�요소�:��뉴런,�시냅스�
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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�신경�전달�물질의�양에�따라서�다른�신호가�전달
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
10
�신경�전달�물질의�양에�따라서�다른�신호가�전달
(1958)
Frank Rosenblatt
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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단층�퍼셉트론�모델
XXX
input�layer output�layer
Y0
1
2
Sw0
w1
w2
활성화�함수�(Activation�function)
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
13
단층�퍼셉트론�모델
XXX
input�layer output�layer
Y0
1
2
Sw0
w1
w2
활성화�함수�(Activation�function)
But…
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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XOR�ProblemOR�Problem
O.OO. II . II .O
O
I
XOR�Problem
O.OO. II . II .O
O
IO
둘�중�하나만�참이어도�참 둘�중�하나라도�다르면�거짓
I
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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x
y
XX
x
y
X
X
linear model
???
다층�퍼셉트론�모델
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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x
y
X
X
Non-linear model
_아무리�선을�잘�그어도�구분할�수가�없다.�
_비�선형�분류�방법의�필요성�대두�
_은닉층이�포함된�다층�퍼셉트론�모델의�등장
다층�퍼셉트론�모델
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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다층�퍼셉트론�모델input�layer output�layer
w
hidden�layer
w SS
S
ΣΣ
Σ
back�propagation
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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1.은닉층은�몇�개,�몇�층으로�구성되어야�하는가?�_답은�없다.�계속�해보는�수밖에�
_층이�많아지고�노드가�많아져도�성능이�증가하는�것이�아니다.(딥러닝의�시발점)�
2.초기값�가중치는�어떻게�정하는가?�_초기값에�따라서�결과가�달라질�수�있음.(지역�최적화�문제)�
3.인과관계가�불분명�하다.�_결과가�어떻게�나오는지�중간�과정이�명확하지�않다.
다층�퍼셉트론�모델의�문제
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
What is Support vector machine?
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Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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두개의�클래스를�가진�점들을�어떻게�‘잘’�구분할�수�있을까?
x
y
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
21
점들은�무수히�많은�선들로�분류할�수�있다.
x
y
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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그렇다면�가장�좋은�선은�무엇일까?
x
y
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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두�클래스간�여유공간이�가장�많은�면(Maximum�margin)
x
y
support�vector
margin
hyperplane
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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1차원�문제라면…?
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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1차원�문제라면…?
구분�불가
(?)
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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1차원�문제라면…?
???
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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어떻게�하면�좋을까?
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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차원을�늘려본다면…?
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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보이지�않던�경계면이�보일�수도�있다!
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
30
보이지�않던�경계면�:�line,�plane이�아닌�hyperplane(초평면)
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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kernal�trick
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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분류상에서�최적의�분류선을�보장
ANN�vs�SVM
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
33
1.커널�선택의�어려움�_데이터의�속성에�따라�적합한�커널이�달라짐�
2.차원의�저주�_차원이�높은�데이터의�최적�분류�평면을�찾기�위한�시간이�매우�오래�걸림
SVM의�문제
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
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1.양질의�데이터�2.전처리�
->좋은�데이터를�많이�넣어서�학습시키자!�-�구글이�잘할수�밖에�없는�이유
Deep�learning
Designer programmer meet Seminar 2016/11/19
_Lee ji-yun
Thank you for your listening!
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