We present a formal model of a distributed consensus algorithm in the executable specification language Promela extended with a new type of guards, called counting guards, needed to implement transitions that depend on majority voting. Our formalization exploits abstractions that follow from reduction theorems applied to the specific case-study. We apply the model checker Spin to automatically ...

Chairman Mao first initiated the Great Proletarian Cultural Revolution in 1966 in order to expel capitalist influences within the Party and solidify his position as the supreme leader of China. In his " 16 Points, " Mao called on the masses and youth of China to rise up and " strike at the handful of ultra-reactionary bourgeois Rightists and counter-revolutionary revisionists, and expose and cr...

We give a new proof of the result, due to A. LaPaugh, that a graph may be optimally " searched " without clearing any edge twice. o 19~~ Academic PWS, IIIC. Let us regard a graph as a system of tunnels containing a (lucky, invisible, fast) fugitive. We desire to capture this fugitive by " searching " all edges of the graph, in a sequence of discrete steps, while using the fewest possible " guar...

Division of labor among workers is common in insect societies and is thought to be important in their ecological success. In most species, division of labor is based on age (temporal castes), but workers in some ants and termites show morphological specialization for particular tasks (physical castes). Large-headed soldier ants and termites are well-known examples of this specialization. Howeve...

In the eternal dominating set problem, guards form a dominating set on a graph and at each step, a vertex is attacked. After each attack, if the guards can “move” to form a dominating set that contains the attacked vertex, then the guards have successfully defended against the attack. We wish to determine the minimum number of guards required to successfully defend against any possible sequence...

“Entry” guards protect the Tor onion routing system from variants of the “predecessor” attack, that would allow an adversary with control of a fraction of routers to eventually de-anonymize some users. Research has however shown the three guard scheme has drawbacks and Dingledine et al. proposed in 2014 for each user to have a single long-term guard. We first show that such a guard selection st...

In the Art Gallery problem a polygon is given and the goal is to place as few guards as possible so that the entire area of the polygon is covered. We address a closely related problem: how to place a fixed number of guards on the vertices or the edges of a simple polygon so that the total guarded area inside the polygon is maximized. Recall that an optimization problem is called APX-hard, if t...

Building on research previously reported at AAMAS conferences, this paper describes an innovative application of a novel gametheoretic approach for a national scale security deployment. Working with the United States Transportation Security Administration (TSA), we have developed a new application called GUARDS to assist in resource allocation tasks for airport protection at over 400 United Sta...