Virtual Grid Engine: a simulated grid engine environment for large-scale supercomputers.

Background: Supercomputers have become indispensable infrastructures in science and industries. In particular, most state-of-the-art scientific results utilize massively parallel supercomputers ranked in TOP500. However, their use is still limited in the bioinformatics field due to the fundamental fact that the asynchronous parallel processing service of Grid Engine is not provided on them.

Multistate network for loop searching system with self-recovery property.

We propose a network of excitable systems that spontaneously initiates and completes loop searching against the removal and attachment of connection links. Network nodes are excitable systems of the FitzHugh-Nagumo type that have three equilibrium states depending on input from other nodes. The attractors of this network are stationary solutions that form loops, except in the case of an acyclic network.

Multistate network model for the pathfinding problem with a self-recovery property.

In this study, we propose a continuous model for a pathfinding system. We consider acyclic graphs whose vertices are connected by unidirectional edges. The proposed model autonomously finds a path connecting two specified vertices, and the path is represented by a stable solution of the proposed model.

Chaotic motion of propagating pulses in the Gray-Scott model.

Transition routes of propagating pulses in the Gray-Scott model from oscillatory to chaotic motion are investigated by numerical studies. Global bifurcation of the Gray-Scott model gives us information about the onset mechanism of transient dynamics, such as the splitting and extinction of pulses. However, the instability mechanism of oscillatory pulses has not been clarified, even numerically.

Bifurcation of self-motion depending on the reaction order.

As a simple example of an autonomous motor, the characteristic features of self-motion coupled with the acid-base reaction were numerically and experimentally investigated at the air/aqueous interface. Oscillatory and uniform motion were categorized as a function of the reaction order by numerical computations using a mathematical model that incorporates both the distribution of the surface active layer developed from a material particle as the driving force and the kinetics of the acid-base reaction. The nature of the self-motion was experimentally observed for a boat adhered to a camphor derivative with a mono- or di-carboxylic acid on a phosphate aqueous phase as the base.