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Vulnerability of Complex Infrastructure Systems. Torbjörn Thedéen Safety Research, KTH. HAZARDS. Nature-Acts of God: Earthquakes, Extreme floods, Thunder storms ... Failures of material ... Human lapses Organizational errors Hackers Terrorism War. Info Stairs. Many data
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Vulnerability of Complex Infrastructure Systems Torbjörn Thedéen Safety Research, KTH
HAZARDS • Nature-Acts of God: Earthquakes, Extreme floods, Thunder storms ... • Failures of material ... • Human lapses • Organizational errors • Hackers • Terrorism • War
Info Stairs Many data Classical statistical analysis Precursors, Incidents Few data Logical model Reliability methods PRA Subjective Probabilities Bayesian methods
Terrorist Groups Motivation Religious, political, social, economic studiesConditional Power+possibilities Conditional Vulnerability Consequences given ´attacks´: Dams, transportation, power grids... Research Areas
Vulnerability USA October 07 Vulnerability of Road Transportation Systems (Erik Jenelius KTH)
Conditional Vulnerability • Road systems modelled as a connected graph • Conditioned of one link is out, the consequences are estimated: • The increased total traffic time • The unsatisfied demand • The most ´important´ or one link at random is taken out
Example • Northern Sweden • The average traffic is known • The traffic for a disturbed net can be calculated
Vulnerability of Power Net Power Generation Power Transmission Power Distribution and Consumption
Power Generation Dam Safety and Security Safety analysis OK, but security antagonistic threats?? Nuclear Power Plants. PRA safety OK, Defense passive?
Power Nets - Vulnerability • (Statistical Analysis of Collapses) Too few! • Vulnerability analysis of empirical graph model – partly classisfied! • Vulnerability analysis of idealized graph model (coupled branching processes)
Power Net – Graph Model Power stations 400 kV Transformers 110 kV 220 V Consumers …………
Branching Process Consumers Power generation
Limiting result • One link is removed at random. The proportion of unserved consumers has in the limit a distribution with a right tail of power type exponent – 1.
Terrorism Terrorist groups Motivation Common goal Basis Cause fear, chaos and deaths!
TERRORISM AND DEFENSE Partly known Known ? Enemy infrastructure Critical infrastructure
Fighting Terrorism • Knowledge or qualified guesses about probable terrorist groups, their goals and actions constitutes: • Basis for our defence of infrastructures ... • Basis for our actions against terrorist groups
Our critical infrastructures: power, transportation, data, finance, water ... KNOWN TO THE ENEMY! Enemy infrastructure: terrorist groups ALMOST UNKNOWN TO US! Fight Between Two Networks
Terrorist Network Known links and nodes Unknown links and nodes
Sampling Procedures • Random sampling of nodes/links • In time or in time periods • Markov sampling • Markov sampling with side conditions
Estimates – random sampling • Link distribution • Shortest path • Sampling in many time periods – (N, p): • ML estimates of p and N (Size of the terrorist population)