- PowerPoint PPT Presentation

About This Presentation
Title:

Description:

Title Author: Last modified by: Ivan Created Date: 11/25/2006 1:59:19 PM Document presentation format – PowerPoint PPT presentation

Number of Views:24
Avg rating:3.0/5.0
Slides: 42
Provided by: 5009278
Category:
Tags: gnutella

less

Transcript and Presenter's Notes

Title:


1
??? ????? ?? ????? ??????????
  • ????????? ????
  • ?????? ????

2
??????? ??????????
  • 1. ????????
  • 2. ???????
  • 3. ??????? ??????
  • 4. ????, ?????????????? ??????????? ?????
  • 5. ??????
  • 6. ???????? ???????
  • 7. ??????

3
????????
  • ??? ?????
  • ???? ?????????????? ???????????? ? ?????????
  • ????? ??????, ??? ?? ????????? ?????????? ?
    ???????????, ??? ? ??? ???? ????? ????????

4
????????(2)
  • ?????? ?????? ??????????
  • ????????? ????????????? Web
  • ????????? ???????
  • ????????? ????????? (Gnutella, Freenet)

5
??????????? ?????? ????????
  • ??????????? ? 1960?, ???????? ????? ?? ?????
    ??????? ? ????????? ????????
  • ??????? ?? ???????? ?????? ??? ???????? ??????
    ????????, ???????? ? ????????????
  • ????? ???????? ?????????? ????? ? ???

6
???????? ????????
  • ???????? ???? ? ????? ????????? ??????????
  • ???? ????? ???????? ??? ????, ???? ??????
    ?????????? ? ???????? ????

7
???????????? ???? ? ??????
  • ????????? ???? ????? ????????? ???????
  • ???? ? ? ? ??? ??????????? ? ????? ??????, ??
    ?????? ????? ??? ???? ??????.
  • ??, ????? ????????????? ???? ?????????, ?? ?????
    ?????? ????????

8
?????? ????? ? ?????????
  • ??????????? ????? ????????????? ???????????????
    ???? ????????? ? ???????? ????
  • ?????? - ???????? ????
  • ??????? ?????????, ?? ??? ???? ????????? ?????
    ??????????? ????????? ?????????, ??????? ???
    ????????? ?? ?????????

9
???????????? ????? ??????????
  • ?????? ?????????? ???? ????? ?????, ???????????
    ?? ???????? ???? ??????????
  • ?????????? ??????? ????????????? ?????, ??????? ?
    ?????????? ????
  • ?????????????????? ?????????

10
???????? ????? ??????????
  • ???????????? ??????? ????????????, ?????
    ????????? ????? ??????????????????? ?????????
  • ??? ????? ?? ??????? ?????? ?????????? ?????
    ????? ? ????????? ?????????? ??????????????????
    ????????, ????????? ???????? ???????? ???? ?
    ??????? ????????????.
  • ?????????? ?????????? ?????? ? ???? ?????????,
    ??? ??????? ?????????????????? ?????????
    ??????????.

11
?????? ?????? ?? ????
  • ??? ??????????? ???????? ?????????? ????????
  • ??????? ? ??????? ???????? ????????????
    ??????? ????
  • ???? ?????? ????
  • ?????? ? ??????? - ??????????? ???? ?? ??????
    ?????????? ?????????? ?????
  • ????????, ???? ? ???????? - ??????????? ???????
    ???????? ????

12
??????? ??????
  • ???????? ??????
  • ?????????????????? ?????????
  • ?????????? ?????????? ??????
  • k ?????? ????

13
???????? ??????
  • ?????????? ?????n n , (i j) i ? 1 2
    n j ? 1 2
    n
  • ???????? ??????????
  • d((i j) (k l)) k - i l j

14
???????? ??????(2)
  • p gt 1 - ????????? ????????
  • q gt 0 - ????????? ????????
  • r gt 0
  • d(u v)-r- ??????????? ????? ?? u ? v
  • d(u v)-r / ?vd(u v)-r - ?????? ?????
    ????????, ???????? ????????????? ??????? r

15
?????? ???????? ??????
  • ?????????? ????? ? n 6, p 1, q 0

16
?????? ???????? ?????? (2)
  • ???????? ???? u ??? p 1, q 2, ??? v ? w
    ??????? ????????

17
???????? ??????(3)
  • ?????? p ? q ?????????????? ??????????? ????????
    ??????????????????? ????????? ?????, ????????? ??
    ?????????? r
  • r ??????? ????????, ?????????? ??? ??????
    ??????????? ?????? ????
  • ??? r 0 ?????????? ?????? ????? ????????

18
?????????????????? ?????????
  • ?? ?????? ???? ????????? ????????? ?????
  • ????????? ????????? ?????????
  • ?????????????? ???? ?? ???????
  • ?????????????? ? ??????? ???????? ???? ?????,
    ??????? ???? ??????????? ?????????

19
?????????????????? ?????????
  • ????????? ????? ????????
  • ????????? ?????????? ????? ?? ????
  • ????????? ???? ? ???????????? ? ????????
    ????????????? ??????? r
  • ????????? ? ??????? ????? ?????????? ????????
    ??????????

20
?????????? ?????????? ??????
  • ??????? 1
  • ?????????? ????????? a0, ????????? ?? p ? q, ??
    ????????? ?? n, ????? ??? ??? r 0, ?????????
    ????? ???????? ?????? ???????????????????
    ????????? ?? ?????? a0n2/3

21
?????????? ?????????? ?????? (2)
  • ??????? 2
  • ?????????? ?????????????????? ???????? ? ?
    ????????? a2, ??????????? ?? n, ??? ??? ??? r 2
    ? p q 1, ????????? ????? ???????? ?? ??????
    a2(log n)2.

22
??????????????? ?????????
  • ????? ??????? ???????? ????????? ?????????,
    ??????????? ?? ???????????? ??????? ? ??????????
    ??????? ????? ??????????

23
??????? ????????????? ??????
  • ? ?????? ??????? ??????????? ????????????? ??
    ????????? ????????? ???????????? ??????? ?????
    ????????? ???????
  • ???????? A ?????? ??????? ?? ?????? ????
    ????????? ????????? ???????? ??????? ????????
    ??????? ? ???? ? ?????? ???????? ???????

24
???????
  • 0 lt r lt 2
  • ?????????? ????????? ar, ????????? ?? p, q,
    r, ??????????? ?? n, ????? ??? ????????? ?????
    ???????? ?????? ??????????????????? ????????? ??
    ?????? arn(2-r)/3
  • r gt 2
  • ?????????? ????????? ar, ????????? ?? p, q, r,
    ??????????? ?? n, ????? ??? ????????? ?????
    ???????? ?????? ??????????????????? ????????? ??
    ?????? arn(r-2)/(r-1)

25
??????????? ?????????? ??????? ?? ????????????
?????????????
  • ????????? ?????

26
k - ?????? ????
  • ????????? ???????????
  • ???????? ????? ??????? ???? ? ??????,
    ?????????????? ????????? ?? log n, ???? ??????
  • r k

27
???????? ????????
  • ???????? ???????? ?????? ?????
  • ??????????? ???????? ?? ?? ?? ????? ???
    ??????????? ?????????? ???????? ??????
  • ???? ?????? ????????? ??????????? ????? ???????
    ????? ???? ???????????? ??? ??????????? ? ????

28
????, ?????????????? ??????????? ?????
  • ????????????? ??????? ??????
  • ?????? ? ??????????????????? ??????? ???????
  • ?????? ? ?????????? ??????? ???????
  • ????????? ?????????

29
????????????? ??????? ??????
  • b - ????? ?????? T, b const
  • V ????? ??????? ?? T, n ?????? V
  • ??? v ? w, h (v, w) - ?????? ?? ??????????
    ?????? ?????? ? T
  • ?????????? ?????????????? ??????? f(?) -
    ??????????? ????????????? ?????
  • ??? v ? V, f(h(v,w))/?x?v f(h(v, x))
  • ????? ?????? ? - ??????? ??????? ??????

30
?????? ? ??????????????????? ??????? ???????
  • k c log2n, ??? ? const
  • ?????? ?????????????? ???

31
???????????? ????????????? ??????
  • WWW ???????? ??? (yahoo.com)
  • Science/Computer_Science/Algorithms ?????
    ???????? ????? ??????? ? Science/Computer_Science
    /Machine_Learning, ??? ? Arts/Music/Opera

32
?????????? ??????????
  • ???????
  • ? ????????????? ?????? ??????? ? 1 ?
    ??????????????????? ??????? ???????, ? ???????
    ????? ?????? ?????????????????? ??????????
    ??????????? O(log n).

33
?????????? ??????????
  • ???????(???????????)
  • ? ? ? 1, ?? ?????????? ????????????? ??????
    ??????? ? ? ??????????????????? ??????? ???????,
    ? ??????? ?????????????????? ???????? ?????
    ??????? ??????????????????? ????? ??????.

34
????????? ?????????
  • ????? ????? V
  • ???????? ??????????? V
  • ????????? ? lt 1 ? ß gt 1
  • R - ?????? ???????? qgt 2, v ? R, ? R' ? R,
    v ? R' , R' ?????? ??????? R, R' ? ?q
  • R1,R2,R3, . . . ??????, ??????? ?????? ??
    ?????? q ? ?????????? ????? ???? v, ?? ??
    ??????????? ????? ?????? ?? ?????? ßq

35
?????????????? ????????? ?????? c?????? ?
  • (V, Ri)
  • q(v, w) - ?????? ?????????? ?????????
  • f (?) ??????????, ??????????????
  • f (?) ?????? ?????????????? ??? q-?

36
?????????? ??????????
  • ???????
  • ??? ?????? ????????? ????????? ??????????
    ?????????????? ????????? ?????? ??????? ? 1 ?
    ??????????????????? ??????? ???????, ? ???????
    ????? ?????? ?????????????????? ??????????
    ??????????? O (log n).
  • ??? ??????? ? lt 1, ?? ?????????? ??????????????
    ????????? ?????? ??????? ? ? ???????????????????
    ??????? ???????, ? ??????? ??????????????????
    ???????? ????? ??????? ??????????????????? ?????
    ??????.

37
??????
  • ??????????? ????? ????????? ?????????? ? ????????
    ??????????
  • ?????? ???????????? ?????? ?????????? ?????
    ????.
  • ???? ???????????? ???????? ??? ????? ????????
  • ? ??????? ???????? ???? ??????????, ??
    ???????????, ?????????????????? ? ??????????
    ?????????, ?? ????? ?? ?????.

38
???????? ???????
  • ?????? ??????
  • ????? ?? ????????????? ????????? ????? ???????
    ????? ?? ????? ????? ????????????
  • ???????????? ?????-???????????
  • ????????????? ?????

39
??????
  • J. Kleinberg. Navigation in a Small World. Nature
    406 (2000)
  • J. Kleinberg. The small-world phenomenon An
    algorithmic perspective. Proc 32nd Symposium on
    Theory of Computing, 2000
  • J. Kleinberg. Small-world Phenomena and the
    Dynamics of Information. Advances in Neural
    Information Processing Systems (NIPS) 14, 2001.

40
??????(2)
  • J. Kleinberg, P.Raghavan. Query Incentive
    Networks. Proc 46 th IEEE Symposium of
    Foundations of Computer Science, 2005.
  • S. Milgram, The small world problem. Psychology
    Today 1 (1967)/
  • J. Kleinberg. The small world phenomenon and
    Decentralized Search, SIAM News, Volume 37,
    number 3, april 2004
  • ???????? ???????? ????? ??????????.

41
????????
  • ???? ???????
Write a Comment
User Comments (0)
About PowerShow.com