In general, any system may here we focus of losing critical facilities by natural disasters or terrorist attacks. This paper focuses on identifying critical facilities and planning to reduce the effect of this event. A three-level model is suggested in the form of a defender-attackerdefender. It is assumed that the facilities are hierarchical and capable of nesting. Also, the attacker budget fo...

This article poses the following problem: Does there exist a probability distribution over subsets of finite partially ordered set (poset), such that constraints involving marginal probabilities poset’s elements and maximal chains is satisfied? We present combinatorial algorithm to positively resolve this question. The can be implemented in polynomial time special case where chain are affine fu...

The expanse of U.S. transportation systems has helped to facilitate persistent national economic growth, its ease of access and reliability vital to the plethora of users who utilize daily the established infrastructure. Recent events have shown cause for concern, however, as the vulnerability inherent in such transportation systems has been exploited by the calculated attacks of highly motivat...