Modelling and control of cell reaction networks

The project aims at a study of the nonlinear systems arising in the biochemical processes occuring inside a cell. The cellular regulation has been formulated in the more familiar framework used in control and system theory in terms of inputs as the variables which can be influenced externally. A graph-theoretic approach has been taken to elicit the rich structure of the dynamical systems represented by metabolic pathways inside the cell. Problems of realization, analysis, and control of cell reaction networks are described

Memory functions and Correlations in Additive Binary Markov Chains

A theory of additive Markov chains with long-range memory, proposed earlier in Phys. Rev. E 68, 06117 (2003), is developed and used to describe statistical properties of long-range correlated systems. The convenient characteristics of such systems, a memory function, and its relation to the correlation properties of the systems are examined. Various methods for finding the memory function via the correlation function are proposed. The inverse problem (calculation of the correlation function by means of the prescribed memory function) is also solved. This is demonstrated for the analytically solvable model of the system with a step-wise memory function.Comment: 11 pages, 5 figure

Asynchronous Communication in Timed Discrete-Event Systems

A model that allows asynchronous communication between agents in a timed decentralized discrete-event system is presented. Two needs for timing information are addressed: timing relationships between events and the maintenance of clocks for generating timestamps on messages sent between decentralized agents. An existing model of a timed automaton, called an event-recording automaton, is combined with a popular timing framework for determining the causality of messages in distributed systems, called vector clocks

Decentralized Failure Diagnosis with Asynchronous Communication between Supervisors

Decentralized failure diagnosis problems arise in communication networks. Network operators require automated tools to isolate failures that need immediate attention. Failure notification is often accompanied with local timing information, although the presence of a global clock is not guaranteed. A timed discrete-event system for decentralized failure diagnosis is proposed. Additionally, the model allows asynchronous communication between decentralized diagnosers. The problem is treated whether an observor map of a diagnoser factors over a timed discrete-event system with a finite state set