Dynamical behaviors in a dissipative system of particles with an asymmetric interaction, are investigated. In the system, the emergence of a moving pattern appears by the collective motion of particles as the non-trivial valance between the in-and-out flows of energy through the non-equilibrium system. The typical example is a jam formation in traffic flow. Several patterns of collective movements in 2-dimensional space are also presented.
This paper reviews a secret key distribution based on 'Bounded Observability.' First, the secret key agreement from correlated sources is introduced. Next, the notion of Bounded Observability is introduced. This notion means the practical difficulty of completely observing physical phenomena that are too fast, or too large, or too complex. Finally, a secret key distribution scheme by using correlated physical randomness in lasers driven by common random light is introduced.