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Aleksandar Milinković Elektrotehnički fakultet Google-ov PageRank Algoritam Aleksandar Milinković Elektrotehnički fakultet u Beogradu [email protected]

Google-ov PageRank Algoritam

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Google-ov PageRank Algoritam. Aleksandar Milinkovi ć Elektrotehni čki fakultet u Beogradu [email protected]. Uvod. Pretraživanje na webu se razlikuje od klasičnog Web je: Ogroman (oko 40 milijardi stranica) Dinamičan Samoorganizujući Hiperlinkovan. Ovim nije obuhvaćen tzv. d uboki web. - PowerPoint PPT Presentation

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Page 1: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet u Beogradu

[email protected]

Page 2: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

2/16

Pretraživanje na webu se razlikuje od klasičnog

Web je:Ogroman (oko 40 milijardi stranica)

Dinamičan

Samoorganizujući

Hiperlinkovan

Uvod

Ovim nije obuhvaćen tzv. duboki web

Page 3: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

3/16

Principi rada web pretraživača

WWW

Crawler modul

Repozitorijum web stranica

Modul za indeksiranje

Modul za upite

Modul za rangiranje

korisnik

Indeks sadržaja

Indeks specijalne nameme

Moduli nezavisni od upita

Indeks strukture

upit rezultat

Page 4: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

4/16

PageRank Algoritam – model 1

001000

000000

010010

000010

000001

001110 A B C D E F

A B

C

D

E

F

1

1

1

1

1

1

e

1

0

2

1

1

3

eM ?

Zar ne bi trebalo da čvor B ima veći rang od čvora D

Page 5: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

5/16

PageRank Algoritam – model 2

e

0 kk M 1

11

1

0

2

1

1

3

1

1

1

1

1

1

001000

000000

010010

000010

000001

001110

eM 22

2

0

1

1

3

4

1

0

2

1

1

3

001000

000000

010010

000010

000001

001110

eM 33

1

0

3

3

4

5

2

0

1

1

3

4

001000

000000

010010

000010

000001

001110

eM 44

3

0

4

4

5

10

1

0

3

3

4

5

001000

000000

010010

000010

000001

001110

eM 55

4

0

5

5

10

13

3

0

4

4

5

10

001000

000000

010010

000010

000001

001110

eM 66

5

0

10

10

13

20

4

0

5

5

10

13

001000

000000

010010

000010

000001

001110

πeM

77

10

0

13

13

20

33

5

0

10

10

13

20

001000

000000

010010

000010

000001

001110

πeM

88

13

0

20

20

33

46

10

0

13

13

20

33

001000

000000

010010

000010

000001

001110

πeM

?Kada prestati sa iteriranjem?

Rangovi stranica postaju veliki

Page 6: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

6/16

Skaliranje kolona tako da ukupan zbir bude 1

PageRank Algoritam – model 3

0 1 1 1 0 0

1 0 0 0 0 0

0 1 0 0 0 0

0 1 0 0 1 0

0 0 0 0 0 0

0 0 0 1 0 0

M

1 13 2

13

13

12

0 1 0 0

1 0 0 0 0 0

0 0 0 0 0

0 0 0 1 0

0 0 0 0 0 0

0 0 0 0 0

H

0

1en

1k kH

Page 7: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

7/16

PageRank Algoritam – model 30

1 1 13 2 6

16

1 13 60

0 1 13 6

16

1 12 6

0 1 0 0 0.17

1 0 0 0 0 0 0.17

0 0 0 0 0 0.171

0 0 0 1 0 0.17

0 0 0 0 0 0 0.17

0 0 0 0 0 0.17

H en

Rangovi svih stranica konvergiraju ka 0

F je viseći (dangling) čvor

?1

1 1 13 2 6

16

1 13 61

1 1 13 6

16

1 12 6

0 1 0 0 0.31

1 0 0 0 0 0 0.17

0 0 0 0 0 0.061

0 0 0 1 0 0.22

0 0 0 0 0 0 0.00

0 0 0 0 0 0.08

H en

21 1 1

3 2 6

16

1 13 62

2 1 13 6

16

1 12 6

0 1 0 0 0.22

1 0 0 0 0 0 0.31

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.11

H en

31 1 1

3 2 6

16

1 13 63

3 1 13 6

16

1 12 6

0 1 0 0 0.19

1 0 0 0 0 0 0.22

0 0 0 0 0 0.101

0 0 0 1 0 0.10

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

41 1 1

3 2 6

16

1 13 64

4 1 13 6

16

1 12 6

0 1 0 0 0.23

1 0 0 0 0 0 0.19

0 0 0 0 0 0.071

0 0 0 1 0 0.07

0 0 0 0 0 0 0.00

0 0 0 0 0 0.05

H en

51 1 1

3 2 6

16

1 13 65

5 1 13 6

16

1 12 6

0 1 0 0 0.17

1 0 0 0 0 0 0.23

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.04

H en

61 1 1

3 2 6

16

1 13 66

6 1 13 6

16

1 12 6

0 1 0 0 0.17

1 0 0 0 0 0 0.17

0 0 0 0 0 0.081

0 0 0 1 0 0.08

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

71 1 1

3 2 6

16

1 13 67

7 1 13 6

16

1 12 6

0 1 0 0 0.17

1 0 0 0 0 0 0.17

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.04

H en

81 1 1

3 2 6

16

1 13 68

8 1 13 6

16

1 12 6

0 1 0 0 0.14

1 0 0 0 0 0 0.17

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

81 1 1

3 2 6

16

1 13 68

8 1 13 6

16

1 12 6

0 1 0 0 0.14

1 0 0 0 0 0 0.17

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

91 1 1

3 2 6

16

1 13 69

9 1 13 6

16

1 12 6

0 1 0 0 0.14

1 0 0 0 0 0 0.14

0 0 0 0 0 0.061

0 0 0 1 0 0.06

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

101 1 1

3 2 6

16

1 13 610

10 1 13 6

16

1 12 6

0 1 0 0 0.13

1 0 0 0 0 0 0.14

0 0 0 0 0 0.051

0 0 0 1 0 0.05

0 0 0 0 0 0 0.00

0 0 0 0 0 0.03

H en

111 1 1

3 2 6

16

1 13 611

11 1 13 6

16

1 12 6

0 1 0 0 0.12

1 0 0 0 0 0 0.14

0 0 0 0 0 0.051

0 0 0 1 0 0.05

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

121 1 1

3 2 6

16

1 13 612

12 1 13 6

16

1 12 6

0 1 0 0 0.11

1 0 0 0 0 0 0.12

0 0 0 0 0 0.041

0 0 0 1 0 0.04

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

131 1 1

3 2 6

16

1 13 613

13 1 13 6

16

1 12 6

0 1 0 0 0.11

1 0 0 0 0 0 0.11

0 0 0 0 0 0.041

0 0 0 1 0 0.04

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

141 1 1

3 2 6

16

1 13 614

14 1 13 6

16

1 12 6

0 1 0 0 0.10

1 0 0 0 0 0 0.11

0 0 0 0 0 0.041

0 0 0 1 0 0.04

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

151 1 1

3 2 6

16

1 13 615

15 1 13 6

16

1 12 6

0 1 0 0 0.09

1 0 0 0 0 0 0.10

0 0 0 0 0 0.041

0 0 0 1 0 0.04

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

161 1 1

3 2 6

16

1 13 616

16 1 13 6

16

1 12 6

0 1 0 0 0.09

1 0 0 0 0 0 0.09

0 0 0 0 0 0.031

0 0 0 1 0 0.03

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

171 1 1

3 2 6

16

1 13 617

17 1 13 6

16

1 12 6

0 1 0 0 0.08

1 0 0 0 0 0 0.09

0 0 0 0 0 0.031

0 0 0 1 0 0.03

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

181 1 1

3 2 6

16

1 13 618

18 1 13 6

16

1 12 6

0 1 0 0 0.06

1 0 0 0 0 0 0.08

0 0 0 0 0 0.031

0 0 0 1 0 0.03

0 0 0 0 0 0 0.00

0 0 0 0 0 0.02

H en

191 1 1

3 2 6

16

1 13 619

19 1 13 6

16

1 12 6

0 1 0 0 0.06

1 0 0 0 0 0 0.06

0 0 0 0 0 0.031

0 0 0 1 0 0.03

0 0 0 0 0 0 0.00

0 0 0 0 0 0.01

H en

201 1 1

3 2 6

16

1 13 620

20 1 13 6

16

1 12 6

0 1 0 0 0.05

1 0 0 0 0 0 0.06

0 0 0 0 0 0.021

0 0 0 1 0 0.02

0 0 0 0 0 0 0.00

0 0 0 0 0 0.01

H en

211 1 1

3 2 6

16

1 13 621

21 1 13 6

16

1 12 6

0 1 0 0 0.05

1 0 0 0 0 0 0.05

0 0 0 0 0 0.021

0 0 0 1 0 0.02

0 0 0 0 0 0 0.00

0 0 0 0 0 0.01

H en

Page 8: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

8/16

F ne preporučuje nijednu stranicu

Rešenje – F preporučuje sve stranice podjednako

PageRank Algoritam – model 4

1 1 13 2 6

16

1 13 6

1 13 6

16

1 12 6

0 1 0

1 0 0 0 0

0 0 0 0

0 0 0 1

0 0 0 0 0

0 0 0 0

S

1 13 2

13

13

12

0 1 0 0

1 0 0 0 0 0

0 0 0 0 0

0 0 0 1 0

0 0 0 0 0 0

0 0 0 0 0

H

0

1en

1k kS 1 TS H ea

n

0 0 0 0 0 1Ta

Page 9: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

9/16

PageRank Algoritam – model 40

1 1 1 13 2 6 6

1 16 6

1 1 13 6 60

0 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.17

1 0 0 0 0 0.17

0 0 0 0 0.171

0 0 0 1 0.17

0 0 0 0 0 0.17

0 0 0 0 0.17

S en

11 1 1 1

3 2 6 6

1 16 6

1 1 13 6 61

1 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.33

1 0 0 0 0 0.19

0 0 0 0 0.081

0 0 0 1 0.25

0 0 0 0 0 0.03

0 0 0 0 0.11

S en

21 1 1 1

3 2 6 6

1 16 6

1 1 13 6 62

2 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.29

1 0 0 0 0 0.35

0 0 0 0 0.081

0 0 0 1 0.11

0 0 0 0 0 0.02

0 0 0 0 0.14

S en

31 1 1 1

3 2 6 6

1 16 6

1 1 13 6 63

3 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.28

1 0 0 0 0 0.32

0 0 0 0 0.141

0 0 0 1 0.16

0 0 0 0 0 0.02

0 0 0 0 0.08

S en

41 1 1 1

3 2 6 6

1 16 6

1 1 13 6 64

4 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.34

1 0 0 0 0 0.29

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.09

S en

51 1 1 1

3 2 6 6

1 16 6

1 1 13 6 65

5 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.30

1 0 0 0 0 0.36

0 0 0 0 0.111

0 0 0 1 0.13

0 0 0 0 0 0.02

0 0 0 0 0.09

S en

61 1 1 1

3 2 6 6

1 16 6

1 1 13 6 66

6 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.32

0 0 0 0 0.131

0 0 0 1 0.15

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

71 1 1 1

3 2 6 6

1 16 6

1 1 13 6 67

7 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.33

1 0 0 0 0 0.32

0 0 0 0 0.121

0 0 0 1 0.13

0 0 0 0 0 0.01

0 0 0 0 0.09

S en

81 1 1 1

3 2 6 6

1 16 6

1 1 13 6 68

8 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.34

0 0 0 0 0.121

0 0 0 1 0.13

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

91 1 1 1

3 2 6 6

1 16 6

1 1 13 6 69

9 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.32

0 0 0 0 0.131

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

101 1 1 1

3 2 6 6

1 16 6

1 1 13 6 610

10 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.13

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

111 1 1 1

3 2 6 6

1 16 6

1 1 13 6 611

11 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

121 1 1 1

3 2 6 6

1 16 6

1 1 13 6 612

12 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.32

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

131 1 1 1

3 2 6 6

1 16 6

1 1 13 6 613

13 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

141 1 1 1

3 2 6 6

1 16 6

1 1 13 6 614

14 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

151 1 1 1

3 2 6 6

1 16 6

1 1 13 6 615

15 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

161 1 1 1

3 2 6 6

1 16 6

1 1 13 6 616

16 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

171 1 1 1

3 2 6 6

1 16 6

1 1 13 6 617

17 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

181 1 1 1

3 2 6 6

1 16 6

1 1 13 6 618

18 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

191 1 1 1

3 2 6 6

1 16 6

1 1 13 6 619

19 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

201 1 1 1

3 2 6 6

1 16 6

1 1 13 6 620

20 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

211 1 1 1

3 2 6 6

1 16 6

1 1 13 6 621

21 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

221 1 1 1

3 2 6 6

1 16 6

1 1 13 6 622

22 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.31

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

231 1 1 1

3 2 6 6

1 16 6

1 1 13 6 623

23 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

241 1 1 1

3 2 6 6

1 16 6

1 1 13 6 624

24 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

251 1 1 1

3 2 6 6

1 16 6

1 1 13 6 625

25 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

261 1 1 1

3 2 6 6

1 16 6

1 1 13 6 626

26 1 1 13 6 6

1 16 6

1 1 12 6 6

0 1 0 0.32

1 0 0 0 0 0.33

0 0 0 0 0.121

0 0 0 1 0.14

0 0 0 0 0 0.01

0 0 0 0 0.08

S en

Page 10: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

10/16

PageRank Algoritam – model 4

01 1

3 6

16

160

0 1 13 6

1 13 6

16

0 0 1 0 0 0.17

1 0 0 0 0 0 0.17

0 1 0 0 0 0 0.171

0 0 0 0 0 0.17

0 0 0 0 1 0.17

0 0 0 0 1 0 0.17

S en

11 1

3 6

16

161

1 1 13 6

1 13 6

16

0 0 1 0 0 0.22

1 0 0 0 0 0 0.17

0 1 0 0 0 0 0.171

0 0 0 0 0 0.06

0 0 0 0 1 0.22

0 0 0 0 1 0 0.17

S en

21 1

3 6

16

162

2 1 13 6

1 13 6

16

0 0 1 0 0 0.11

1 0 0 0 0 0 0.22

0 1 0 0 0 0 0.171

0 0 0 0 0 0.06

0 0 0 0 1 0.22

0 0 0 0 1 0 0.22

S en

31 1

3 6

16

163

3 1 13 6

1 13 6

16

0 0 1 0 0 0.11

1 0 0 0 0 0 0.11

0 1 0 0 0 0 0.221

0 0 0 0 0 0.06

0 0 0 0 1 0.28

0 0 0 0 1 0 0.22

S en

41 1

3 6

16

164

4 1 13 6

1 13 6

16

0 0 1 0 0 0.13

1 0 0 0 0 0 0.11

0 1 0 0 0 0 0.111

0 0 0 0 0 0.07

0 0 0 0 1 0.30

0 0 0 0 1 0 0.28

S en

51 1

3 6

16

165

5 1 13 6

1 13 6

16

0 0 1 0 0 0.11

1 0 0 0 0 0 0.13

0 1 0 0 0 0 0.111

0 0 0 0 0 0.04

0 0 0 0 1 0.31

0 0 0 0 1 0 0.30

S en

61 1

3 6

16

166

6 1 13 6

1 13 6

16

0 0 1 0 0 0.07

1 0 0 0 0 0 0.11

0 1 0 0 0 0 0.131

0 0 0 0 0 0.04

0 0 0 0 1 0.33

0 0 0 0 1 0 0.31

S en

71 1

3 6

16

167

7 1 13 6

1 13 6

16

0 0 1 0 0 0.08

1 0 0 0 0 0 0.07

0 1 0 0 0 0 0.111

0 0 0 0 0 0.04

0 0 0 0 1 0.36

0 0 0 0 1 0 0.33

S en

81 1

3 6

16

168

8 1 13 6

1 13 6

16

0 0 1 0 0 0.08

1 0 0 0 0 0 0.08

0 1 0 0 0 0 0.071

0 0 0 0 0 0.04

0 0 0 0 1 0.37

0 0 0 0 1 0 0.36

S en

91 1

3 6

16

169

9 1 13 6

1 13 6

16

0 0 1 0 0 0.06

1 0 0 0 0 0 0.08

0 1 0 0 0 0 0.081

0 0 0 0 0 0.02

0 0 0 0 1 0.38

0 0 0 0 1 0 0.37

S en

101 1

3 6

16

1610

10 1 13 6

1 13 6

16

0 0 1 0 0 0.05

1 0 0 0 0 0 0.06

0 1 0 0 0 0 0.081

0 0 0 0 0 0.03

0 0 0 0 1 0.40

0 0 0 0 1 0 0.38

S en

111 1

3 6

16

1611

11 1 13 6

1 13 6

16

0 0 1 0 0 0.05

1 0 0 0 0 0 0.05

0 1 0 0 0 0 0.061

0 0 0 0 0 0.03

0 0 0 0 1 0.41

0 0 0 0 1 0 0.40

S en

121 1

3 6

16

1612

12 1 13 6

1 13 6

16

0 0 1 0 0 0.05

1 0 0 0 0 0 0.05

0 1 0 0 0 0 0.051

0 0 0 0 0 0.02

0 0 0 0 1 0.42

0 0 0 0 1 0 0.41

S en

131 1

3 6

16

1613

13 1 13 6

1 13 6

16

0 0 1 0 0 0.04

1 0 0 0 0 0 0.05

0 1 0 0 0 0 0.051

0 0 0 0 0 0.02

0 0 0 0 1 0.43

0 0 0 0 1 0 0.42

S en

141 1

3 6

16

1614

14 1 13 6

1 13 6

16

0 0 1 0 0 0.03

1 0 0 0 0 0 0.04

0 1 0 0 0 0 0.051

0 0 0 0 0 0.02

0 0 0 0 1 0.44

0 0 0 0 1 0 0.43

S en

151 1

3 6

16

1615

15 1 13 6

1 13 6

16

0 0 1 0 0 0.03

1 0 0 0 0 0 0.03

0 1 0 0 0 0 0.041

0 0 0 0 0 0.02

0 0 0 0 1 0.44

0 0 0 0 1 0 0.44

S en

161 1

3 6

16

1616

16 1 13 6

1 13 6

16

0 0 1 0 0 0.03

1 0 0 0 0 0 0.03

0 1 0 0 0 0 0.031

0 0 0 0 0 0.01

0 0 0 0 1 0.45

0 0 0 0 1 0 0.44

S en

171 1

3 6

16

1617

17 1 13 6

1 13 6

16

0 0 1 0 0 0.02

1 0 0 0 0 0 0.03

0 1 0 0 0 0 0.031

0 0 0 0 0 0.01

0 0 0 0 1 0.45

0 0 0 0 1 0 0.45

S en

181 1

3 6

16

1618

18 1 13 6

1 13 6

16

0 0 1 0 0 0.02

1 0 0 0 0 0 0.02

0 1 0 0 0 0 0.031

0 0 0 0 0 0.01

0 0 0 0 1 0.46

0 0 0 0 1 0 0.45

S en

191 1

3 6

16

1619

19 1 13 6

1 13 6

16

0 0 1 0 0 0.02

1 0 0 0 0 0 0.02

0 1 0 0 0 0 0.021

0 0 0 0 0 0.01

0 0 0 0 1 0.46

0 0 0 0 1 0 0.46

S en

201 1

3 6

16

1620

20 1 13 6

1 13 6

16

0 0 1 0 0 0.02

1 0 0 0 0 0 0.02

0 1 0 0 0 0 0.021

0 0 0 0 0 0.01

0 0 0 0 1 0.47

0 0 0 0 1 0 0.46

S en

211 1

3 6

16

1621

21 1 13 6

1 13 6

16

0 0 1 0 0 0.02

1 0 0 0 0 0 0.02

0 1 0 0 0 0 0.021

0 0 0 0 0 0.01

0 0 0 0 1 0.47

0 0 0 0 1 0 0.47

S en

221 1

3 6

16

1622

22 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.02

0 1 0 0 0 0 0.021

0 0 0 0 0 0.01

0 0 0 0 1 0.47

0 0 0 0 1 0 0.47

S en

231 1

3 6

16

1623

23 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.021

0 0 0 0 0 0.01

0 0 0 0 1 0.48

0 0 0 0 1 0 0.47

S en

241 1

3 6

16

1624

24 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.01

0 0 0 0 1 0.48

0 0 0 0 1 0 0.48

S en

251 1

3 6

16

1625

25 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.48

0 0 0 0 1 0 0.48

S en

261 1

3 6

16

1626

26 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.48

0 0 0 0 1 0 0.48

S en

271 1

3 6

16

1627

27 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.48

S en

281 1

3 6

16

1628

28 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

291 1

3 6

16

1629

29 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

301 1

3 6

16

1630

30 1 13 6

1 13 6

16

0 0 1 0 0 0.01

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

311 1

3 6

16

1631

31 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.01

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

321 1

3 6

16

1632

32 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.011

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

331 1

3 6

16

1633

33 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

341 1

3 6

16

1634

34 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

351 1

3 6

16

1635

35 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

361 1

3 6

16

1636

36 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.49

0 0 0 0 1 0 0.49

S en

371 1

3 6

16

1637

37 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.50

0 0 0 0 1 0 0.49

S en

381 1

3 6

16

1638

38 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.50

0 0 0 0 1 0 0.50

S en

391 1

3 6

16

1639

39 1 13 6

1 13 6

16

0 0 1 0 0 0.00

1 0 0 0 0 0 0.00

0 1 0 0 0 0 0.001

0 0 0 0 0 0.00

0 0 0 0 1 0.50

0 0 0 0 1 0 0.50

S en

Page 11: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

11/16

Nema visećih čvorova, ali E i F formiraju ciklus

Zajedno apsorbuju sve rangove

Uvodi se α – dumping factor – [0,1]

Predstavlja procenat out link vrednosti

Ostatak se ravnopravno raspoređuje na sve stranice

α ≈ 85% dalje najbolji rezultat

PageRank Algoritam – model 5

1(1 )( ee )TG S

n

Page 12: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

12/16

PageRank Algoritam – model 5

00

0.17

0.17

0.171

0.17

0.17

0.17

G en

11

0.21

0.17

0.171

0.07

0.21

0.17

G en

22

0.13

0.21

0.171

0.07

0.21

0.21

G en

33

0.13

0.14

0.201

0.07

0.25

0.21

G en

44

0.14

0.14

0.141

0.08

0.26

0.24

G en

55

0.14

0.15

0.141

0.07

0.27

0.24

G en

66

0.12

0.14

0.151

0.07

0.27

0.25

G en

77

0.12

0.13

0.141

0.07

0.28

0.26

G en

88

0.12

0.13

0.131

0.07

0.28

0.26

G en

99

0.12

0.13

0.141

0.06

0.29

0.27

G en

1010

0.12

0.13

0.141

0.06

0.29

0.27

G en

1111

0.12

0.12

0.131

0.06

0.29

0.27

G en

1212

0.12

0.12

0.131

0.06

0.29

0.27

G en

1313

0.12

0.12

0.131

0.06

0.29

0.27

G en

1414

0.11

0.12

0.131

0.06

0.30

0.28

G en

1515

0.11

0.12

0.131

0.06

0.30

0.28

G en

1616

0.11

0.12

0.131

0.06

0.30

0.28

G en

1717

0.11

0.12

0.131

0.06

0.30

0.28

G en

1818

0.11

0.12

0.131

0.06

0.30

0.28

G en

1919

0.11

0.12

0.131

0.06

0.30

0.28

G en

Brza konvergencija!

Page 13: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

13/16

Matrica je gusta matrica

Složenost množenja je

Računanje

G

G 2( )O n1

(1 )( ee )TG Sn

1k kG

1 TS H ean

Matrica G nije potrebna!

H je vrlo retka matrica

Vremenska složenost množenja je ( )O n

Page 14: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

14/16

PageRank dobar za indeksiranje strukture

Predstavlja reputaciju stranice

Ukupno rangiranje zavisi i od sadržaja

Indeksiranje se radi off-line

Na PageRank je teško uticati

Na ukupno rangiranje može preko SEO

Zaključak

Page 15: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

15/16

PigeonRank

Page 16: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

16/16

1. S. Brin and L. Page, “The anatomy of a large-scale hypertextual Web search engine,” Computer Networks and ISDN Systems, vol. 33, pp. 107–117, 1998.

2. A. N. Langville and C. D. Meyer, “Deeper inside PageRank,” Internet Mathematics, vol. 1, no. 3, pp. 335–380, 2004.

3. P. Berkhin, “A survey on PageRank computing,” Internet Mathematics, vol. 2, no. 1, pp. 73–120, 2005.

4. S. Serra-Capizzano, “Jordan canonical form of the Google matrix: a potential contribution to the PageRank computation,” SIAM J. Matrix Anal. Appl., vol. 27, no. 2, pp. 305–312, 2005.

5. A. N. Langville and C. D. Meyer, Google’s PageRank and beyond: The Science of Search Engine Rankings, Princeton University Press, 2006.

Literatura

Page 17: Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet

Google-ov PageRank Algoritam

Aleksandar MilinkovićElektrotehnički fakultet u Beogradu

[email protected]