Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern...

35
Human Travel Patterns Albert-László Barabási Albert-László Barabási Center for Complex Networks Research, Center for Complex Networks Research, Northeastern U. Northeastern U. Department of Medicine, Harvard U. Department of Medicine, Harvard U. BarabasiLab.com

Transcript of Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern...

Page 1: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Human Travel Patterns

Albert-László BarabásiAlbert-László Barabási

Center for Complex Networks Research, Northeastern U.Center for Complex Networks Research, Northeastern U.

Department of Medicine, Harvard U.Department of Medicine, Harvard U.

BarabasiLab.com

Page 2: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Tropical forest in Yucatan, Mexico

“Lévy flight” by a spider monkey

Page 3: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.
Page 4: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Animal MotionAnimal Motion

Vishwanatan et. al. Nature (1996); Nature (1999).

Wandering AlbatrossWandering Albatross

Wandering AlbatrossWandering Albatross

Page 5: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Sims et al. Nature (2008).

1 Jun

22 Jun

24 May

7 Aug

11 Jul

28 Jul

5 Jan

10 Oct

24 Nov

Basking shark

Page 6: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Porbeagle shark Sims et al. Nature (2008).

Page 7: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Random Walks Lévy flights

Page 8: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Human MotionHuman Motion

Brockmann et. al. Nature (2006)

Page 9: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

A real human trajectory

Page 10: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Mobile Phone Users

Page 11: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

Data Collection Limitations

We know only the tower the user communicates with, not the real location.

We know the location (tower) only when the user makes a call.

Interevent times are bursty (non-Poisson process—Power law interevent time distribution).

Page 12: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

ALB, Nature 2005.

Page 13: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

Interevent TimesInterevent Times

J. Candia et al.

A-L. B, Nature 2005.

Page 14: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

0 km 300 km100 km 200 km

0 km

100

km

200

km

Mobile Phone Users

Page 15: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Two possible explanations

1.Each users follows a Lévy flight

2.The difference between individuals follows a power law

β=1.75±0.15

Page 16: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Understanding human trajectoriesUnderstanding human trajectories

Radius of Radius of Gyration:Gyration:

Center of Mass:Center of Mass:

Page 17: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Characterizing human trajectoriesCharacterizing human trajectories

Radius of Radius of Gyration:Gyration:

Page 18: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

Characterizing human trajectoriesCharacterizing human trajectories

Radius of Radius of Gyration:Gyration:

Page 19: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

βr=1.65±0.15

Scaling in human trajectoriesScaling in human trajectories

Page 20: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

0 km 300 km100 km 200 km

0 km

100

km

200

km

Mobile Phone Users

Page 21: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

β=1.75±0.15βr=1.65±0.15

Scaling in human trajectoriesScaling in human trajectories

α=1.2

Page 22: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Relationship between exponentsRelationship between exponents

Jump size distribution P(Δr)~(Δr)-β represents a convolution between

*population heterogeneity P(rg)~rg-βr

*Levy flight with exponent α truncated by rg

Page 23: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

Return time distributionsReturn time distributions

Page 24: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Mobile Phone Users

Page 25: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.
Page 26: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

The shape of human trajectoriesThe shape of human trajectories

Page 27: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

CCNRCCNR

The shape of human trajectoriesThe shape of human trajectories

Page 28: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Mobile Phone Viruses

Hypponen M. Scientific American Nov. 70-77 (2006).

Page 29: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Spreading mechanism for cell phone viruses

Short range infection process(similar to biological viruses, like influenza or SARS)

Long range infection process(similar to computer viruses)

Page 30: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Palla, A.-L. B & Vicsek (2007).Onella et al, PNAS (2007)

Social Network (MMS virus)

González, Hidalgo and A-L.B.,

Nature 453, 779 (2008)

Human Motion(Bluetooth virus)

MMS and Bluetooth Viruses

Page 31: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Spatial Spreading Patterns of Bluetooth and MMS virus

Page 32: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Spatial Spreading patterns of Bluetooth and MMS viruses

Bluetooth Virus MMS Virus

Driven by Human Mobility:Slow, but can reach all users with time.

Driven by the Social Network:Fast, but can reach only a finite fraction of users (the giant component).

What is the origin of this saturation?

Page 33: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Spreading mechanism for cell phone viruses

If the market share of an Operating Systemis under mc~10%, MMS

viruses cannot spread.

Page 34: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

0 km 300 km100 km 200 km

0 km

100

km

200

km

Mobile Phone Users

Page 35: Human Travel Patterns Albert-László Barabási Center for Complex Networks Research, Northeastern U. Department of Medicine, Harvard U. BarabasiLab.com.

Pu Wang Cesar Hidalgo

CollaboratorsCollaborators

Marta Gonzalez

www.BarabasiLab.com