Jangsea Park
August 13, 2017
930

# [PyConKR2017] 온라인 게임에서의 이항 분포

August 13, 2017

## Transcript

1. ৡۄੋ ѱ੐ীࢲ੄ ੉೦࠙ನ
ই੉మ ъച ഛܫ ࠙ࢳ
-[|]- Box and Whisker
߅੢द

2. Ѿҗܳ ঌ ࣻ হח प೷

3. ಴ࠄ ҕр
ز੹ ؍૑ӝ
H T
Prob: 0.5 Prob: 0.5

4. ಴ࠄ ҕр
ই੉మ ъച
S F
Prob: 0.1 Prob: 0.9

5. ഛܫ ߸ࣻ X
S F
Prob: 0.1 Prob: 0.9
0 1 2 3 4 5
X

6. ഛܫ ߸ࣻ X = x
X = x {s ∈ S : X(s) = x}
X = 1 {success}
X = 0 {fail}
S F
Prob: 0.1 Prob: 0.9
0 1 2 3 4 5
X

7. ഛܫ ೣࣻ P(X=x) = f(x)
P(X = x) = f(x)
P(X = 1) = f(1) = 0.1
P(X = 0) = f(0) = 0.9
S F
Prob: 0.1 Prob: 0.9
0 1 2 3 4 5
X f
0 1
0.1
0.9
x
p

8. ߬ܰ־੉ द೯
https://en.wikipedia.org/wiki/Bernoulli_trial
S F
Prob: 0.1 Prob: 0.9
0 1 2 3 4 5
X f
0 1
0.1
0.9
x
p

9. ੉೦ ࠙ನ
https://en.wikipedia.org/wiki/Binomial_distribution

10. ੉೦ ࠙ನ
https://en.wikipedia.org/wiki/Binomial_distribution
0
0 1 2 3 4 5
X f
1 2 3
4 5 6 7
8 9 10
6 7 8 9 10

11. ੉೦ ࢎѤ੄ ࣻ
1 2 3 4 5

12. ੉೦ ࠙ನ vs ਺੉೦ ࠙ನ
੉೦࠙ನ
ﬁxed
n: ୨ द೯ ࣻ
p: ࢿҕ ഛܫ
variable
k: ࢿҕ പࣻ
k <= n
count
੿೧૓ द೯ പࣻ ೞীࢲ
ࢿҕೞח പࣻ
਺੉೦࠙ನ
ﬁxed
n: ୨ ࢿҕ പࣻ
p: ࢿҕ ഛܫ
variable
k: पಁ പࣻ
0 <= k < inf
count
੿೧૓ ࢿҕ പࣻܳ ׳ࢿೡ ٸө૑
पಁೞח പࣻ

13. ਺੉೦ ࠙ನ
https://en.wikipedia.org/wiki/Negative_binomial_distribution

14. ਺੉೦ ࠙ನ
https://en.wikipedia.org/wiki/Negative_binomial_distribution
0
0 1 2 3 4 5
X f
1 2 3
4 5 6 7
8 9 inf
6 7 8 inf

15. ਺੉೦ ࢎѤ੄ ࣻ
1 2 3 4 p

16. ਺੉೦ ࠙ನ੄ ׮ܲ ಴ӝߨ
k: पಁ, n: ࢿҕ
k: ࢿҕ, r: पಁ
nCr = nCn-r
5 choose 3 = 5 choose 2
x: ୨ दب, r: पಁ
x = k + r

17. P(X<=90) = ?

18. P(X<=?) = 0.5

19. P(X<=?) = 0.99

20. P(X<=?) = 1.0

21. ؊ ࠂ੟ೠ ޙઁ: ݽ੄प೷

22. جܿ౸
0
0.1

23. +6ъ 100,000 ݺ

24. +7ъ 100,000ݺ

25. +10ъ 100,000ݺ

26. Q & A