复旦大学：《网络科学导论 Introduction to Network Science》教学课件_7- Robustness and fragile

Network science An English introductory course for undergraduate students Lecturer: Dr. Cong LI ee@ Fudan University Adaptive Networks and Control Lab

Network Science Lecturer: Dr. Cong LI EE @ Fudan University —— An English introductory course for undergraduate students Adaptive Networks and Control Lab

Recall: Types of networks Regular graphs Erdos-Renyi (Publ. Math. Inst. Hung. Acd. Sci. 5, 17 (1960) P N nodes, eac rewiring of links pair of nodes are connected with P=02 probability p on or nks Random networks Small world networks Scale-free networks

2 Recall: Types of Networks Regular graphs Random networks Small world networks Scale-free networks

Different roles, different points If you want todestroy a networking system. how to locate your targets? If you want to guard a networking system how to assign your safety measures?

Different roles, different points • If you want to ‘destroy’ a networking system, how to locate your targets? • If you want to ‘guard’ a networking system, how to assign your safety measures? 3

Which players will you pay more FCB attention when you play a football game? 3a如 wa.wa> 【1马 阿网马 阿余地 普健你 c钠永多 卡西啊 旦拿 【2】巴萨 网你比鼻尔 伊 周日4 阿障 7小 马新直你

Which players will you pay more attention when you play a football game?

no one in reality is such a bulletproof super-hero neither is a network CHOW YUN-FAT SEANN WILLIAM SCOTT BULLETPROOF MONK

No one in reality is such a bulletproof super-hero, neither is a network 5

http://www.nytimes.com/2010/03/21/world/asia/21gridhtml New York Times 2010/3/21 L M. Wortzel (usa military strategist Chinese researchers . published a paper on my comment: how to attack a small power-grid sub Take it easy. network in a way that would cause a cascading failure of the entire whole US ELECTRICAL POWERGRID ors transfe dges:transmission lines 6

New York Times, 2010/3/21 • L.M. Wortzel (USA military strategist): Chinese researchers …published a paper on how to attack a small power-grid sub￾network in a way that would cause a cascading failure of the entire whole US. http://www.nytimes.com/2010/03/21/world/asia/21grid.html my comment: Take it easy! 6

Start from simple examples

Start from simple examples……

The assumed victim (a) (b) C Remove which node or edge to destroy?

The assumed victim • Remove which node or edge to destroy? 8

So, which one is vulnerable to destroy [a) (c)

So, which one is vulnerable to destroy? 9

Two categories of“ destroyers” To destroy the connectivity of a network errors and failures(random occurrence) purposely attacks(specific targets)

Two categories of “destroyers” To destroy the connectivity of a network, • errors and failures (random occurrence) • purposely attacks (specific targets) 10