In a system where noncooperative agents share a common resource, we propose the price of anarchy, which is the ratio between the worst possible Nash equilibrium and the social optimum, as a measure of the effectiveness of the system. Deriving upper and lower bounds for this ratio in a model where several agents share a very simple network leads to some interesting mathematics, results, and open...

A continuous tension exists between the day to day requirements for a new product and the requirements in exceptional cases. The System Architect must understand both requirements and be able to discuss them in terms of value in order to make a balanced product. This article gives some handles to tackle this problem. This article builds upon the paper "Requirements Capturing by the System Archi...

We use the assumption that all sets in NP or other levels of the polynomial time hierarchy have e cient average case algorithms to derive collapse consequences for MA AM and various subclasses of P poly As a further consequence we show for C fP PP PSPACEg that C is not tractable in the average case unless C P