Observability of Boolean control networks

Serval existing definitions for observability of Boolean control networks (BCNs) are revisited and a new definition termed observability via output feedback is proposed. This definition restricts the input sequences used to distinguish distinct initial states to be generated by output feedbacks. A technique called parallel extension is proposed for observability analysis, the main idea of which is to interconnect a BCN with its duplication in parallel and transfer the observability problem of the original BCN to the set reachability problem of the interconnected BCN. Novel necessary and sufficient conditions for observability and observability under arbitrary inputs have been given, respectively. In addition, by restricting the output feedback to be static, a sufficient condition for observability via output feedback is proposed. An example is given to illustrate the main results.

The observability of Boolean control networks is investigated. The pairs of states are classified into three classes: (i)diagonal, (ii) h-distinguishable, and h-indistinguishable. For h-indistinguishable pairs, we construct a matrix W called the transferable matrix, which indicates the control-transferability among h-indistinguishable pairs. Modifying W yields a matrix U0, which is used as the initial matrix for an iterative algorithm. After finite iterations a stable Uk∗ is reached, which is called the observability matrix. It is proved that a Boolean control network is observable, if and only if, the last column for all rows of Uk∗ are one. Some numerical examples are presented.

A note on observability of Boolean control networks

Input observability of Boolean control networks

Observability of Boolean networks via set controllability approach

Nominal Boolean network is a kind of Boolean network, which is obtained from a Boolean control network with all controls disconnected. In this paper, the relationship between the transition matrix of the original Boolean control network and the transition matrix of the corresponding nominal Boolean control network is investigated. Due to the fact that transition matrices can be derived from structure matrices, the relationship between structure matrices of the original Boolean control network and structure matrices of the nominal Boolean network is studied. Via constant values corresponding to disconnected controls, structure matrices of the nominal Boolean network can be derived from structure matrices of the original Boolean control network. Finally, a concrete algorithm is presented to derive transition matrices of nominal Boolean networks.

The paper deals with problems on the stability and stabilization of Boolean networks with respect to a given part of variables characterizing the Boolean network. Using the semi-tensor product of matrices and the matrix expression of logic, the dynamics of a Boolean (control) network can be converted to discrete time linear (bilinear) dynamics called the algebraic form of the Boolean (control) network. The two main results are as follows: (i) From the algebraic form of a Boolean (control) network, two partial stability definitions are introduced. One is partial stability with respect to another variable set, and the other is partial stability with respect to arbitrary initial states. (ii) Based on the algebraic form, necessary and sufficient conditions for the stability of global partial states with respect to the variable set and arbitrary initial states are obtained. Examples are provided to illustrate the effectiveness of our results.

In this article, the controllability of asynchronous Boolean control networks (ABCNs) with time-invariant delay is studied. Using semi-tensor product, Boolean control networks under Harvey’s asynchronous update with time delay are converted into linear representation, and a general formula of control-depending network transition matrices is achieved. Firstly, a necessary and sufficient condition is proposed to verify that only control-depending fixed points of ABCNs can be deterministically controlled. Secondly, respectively for three kinds of controls, the controllability of the non-deterministic logical dynamics is investigated, and formulas are given to show: a) the reachable sets at time s under a group of specified controls; b) the reachable sets at time s under arbitrary controls and c) the probability values from a given initial state to different target states. Moreover, we also discuss how to find the particular control sequence to reach a specified target state with the maximum probability. Examples are shown to illustrate the feasibility of the proposed scheme.

In this article, the controllability of asynchronous Boolean multiplex control networks (ABMCNs) is studied. First, the model of Boolean multiplex control networks under Harvey' asynchronous update is presented. By means of semi-tensor product approach, the logical dynamics is converted into linear representation, and a generalized formula of control-depending network transition matrices is achieved. Second, a necessary and sufficient condition is proposed to verify that only control-depending fixed points of ABMCNs can be controlled with probability one. Third, using two types of controls, the controllability of system is studied and formulae are given to show: (a) when an initial state is given, the reachable set at time s under a group of specified controls; (b) the reachable set at time s under arbitrary controls; (c) the specific probability values from a given initial state to destination states. Based on the above formulae, an algorithm to calculate overall reachable states from a specified initial state is presented. Moreover, we also discuss an approach to find the particular control sequence which steers the system between two states with maximum probability. Examples are shown to illustrate the feasibility of the proposed scheme.

The stability of Boolean networks and the stabilization of Boolean control networks are investigated. Using semi-tensor product of matrices and the matrix expression of logic, the dynamics of a Boolean (control) network can be converted to a discrete time linear (bilinear) dynamics, called the algebraic form of the Boolean (control) network. They provide a framework for this study. Main results consist of two parts: (i) Using logic coordinate transformation, the known sufficient condition based on incidence matrix has been improved. It is also used in stabilizer design. (ii)Based on algebraic form, necessary and sufficient conditions for stability of Boolean networks and stabilization of Boolean control networks respectively are obtained.

Disturbance decoupling of Boolean networks via robust indistinguishability method

On the ensemble controllability of Boolean control networks using STP method

Controllability and observability of Boolean control networks subject to stuck-at fault

The concept of bisimulation has been recently introduced in the study of Boolean control networks (BCNs). The notion provides a perspective that explains how a state trajectory of one BCN can be paired with a state trajectory of another BCN, and vice versa. The present paper further pursues the notion of bisimulation in BCNs. It first gives necessary and sufficient conditions for checking this notion. The conditions are more general and neater than those previously published; more importantly, they allow us to go further to consider reducing a BCN via bisimulation. A bisimulation-based methodology is then proposed to reduce the size of the state space of a BCN. Applying the reduction methodology allows one to infer control properties of a BCN from those of the corresponding reduced system. Possibilities of applications of the results are illustrated on several Boolean models of real biomolecular systems.

Minimum energy control and optimal-satisfactory control of Boolean control network