About

Affiliations and memberships

IEEE / Senior Member

Research

Research interests

Supervision

Postgraduate research supervision

Publications

K. Zhang (2022) Detectability of labeled weighted automata over monoids, Discrete Event Dynamic Systems, 60 pages, accepted in 2022.
K. Zhang (2023) Polynomial-time verification and enforcement of delayed strong detectability for discrete-event systems. IEEE Transactions on Automatic Control, accepted, 6 pages, accepted in 2021.
K. Zhang and L. Zhang and L. Xie (2020) Discrete-Time and Discrete-Space Dynamical Systems, of Communications and Control Engineering. Springer International Publishing, 222 pages, 2020.
K. Zhang (2021) A unified method to decentralized state detection and fault diagnosis/prediction of discrete-event systems. Fundamenta Informaticae, 181, 339-371, 2021.
K. Zhang and A. Giua (2020) On detectability of labeled Petri nets and finite automata. Discrete Event Dynamic Systems, 30 (3), 465-497, 2020.
K. Zhang (2017) The problem of determining the weak (periodic) detectability of discrete event systems is PSPACE-complete. Automatica, 81, 217-220, 2017.
K. Zhang and X. Yin and M. Zamani (2019) Opacity of nondeterministic transition systems: A (bi)simulation relation approach. IEEE Transactions on Automatic Control, 64 (12), 5116-5123, Dec 2019.
K. Zhang and K.H. Johansson (2020) Efficient verification of observability and reconstructibility for large Boolean control networks with special structures. IEEE Transactions on Automatic Control, 65 (12), 5144-5158, 2020.
K. Zhang and L. Zhang (2016) Observability of Boolean control networks: A unified approach based on finite automata. IEEE Transactions on Automatic Control, 61 (9), 2733-2738, Sept 2016.
K. Zhang and L. Zhang and L. Xie (2015) Invertibility and nonsingularity of Boolean control networks. Automatica, 60, 155-164, 2015.
K. Zhang and J. Raisch (2021) Diagnosability of labeled weighted automata over the monoid $(\mathbb{Q}_{\ge0},+,0)$. In the 60th IEEE Conference on Decision and Control, Austin, Texas, USA, December 13-15 2021.
K. Zhang (2021) State-based opacity of real-time automata. In 27th IFIP WG 1.5 International Workshop on Cellular Automata and Discrete Complex Systems (AUTOMATA 2021), Dagstuhl, Germany, 12:1–12:15, (Marseille, France, July 12–17 2021).
L. Zhang and K. Zhang (2013) Controllability and observability of Boolean control networks with time-variant delays in states. IEEE Transactions on Neural Networks and Learning Systems, 24(9), 1478-1484, 2013.
K. Zhang (2022) Synthesis for observability of logical control networks. Automatica, accepted in 2022.
K. Zhang (2022) How attacks affect detectability in discrete-event systems? 2022 American Control Conference, July 8-10, 2022, Atlanta, USA, accepted.
W. Dong, X. Yin, K. Zhang, S. Li (2022) On the verification of detectability for timed systems. 2022 American Control Conference, July 8-10, 2022, Atlanta, USA, accepted.
T. Zhang, K. Zhang (2022) Eventual strong detectability of labeled weighted automata over monoids, accepted, 16th IFAC Workshop on Discrete Event Systems, September 7-8, 2022, Prague, Czechia
X. Han, K. Zhang, Z. Li. (2022) Verification of strong K-step opacity for discrete-event systems, accepted, the 61st IEEE Conference on Decision and Control, December 6–9, 2022, in Cancún, Mexico.
K. Zhang (2022) A survey on observability of Boolean control networks, accepted, Control Theory and Technology, 40 pages
Observability is a fundamental property of a partially-observed dynamical system, which means whether one can use an input sequence and the corresponding output sequence to determine the initial state. Observability provides bases for many related problems such as state estimation, identification, disturbance decoupling, controller synthesis, etc. Until now, fundamental improvement has been obtained in observability of Boolean control networks mainly based on two methods — Edward F. Moore’s partition and our observability graph (or their equivalent representations found later based on the semitensor product (STP) of matrices (where the STP was proposed by Daizhan Cheng)), including necessary and sufficient conditions for different types of observability, extensions to probabilistic Boolean networks (PBNs) and singular BCNs, even to nondeterministic finite-transition systems (NFTSs); and the development (with the help of the STP of matrices) in related topics such as computation of smallest invariant dual subspaces of BNs containing a set of Boolean functions, multiple-experiment observability verification/decomposition in BCNs, disturbance decoupling in BCNs, etc. This paper provides a thorough survey for these topics. The contents of the paper are guided by the above two methods. First, we show that Moore’s partition-based method closely relates the following problems: computation of smallest invariant dual subspaces of BNs, multiple-experiment observability verification/decomposition in BCNs, and disturbance decoupling in BCNs. However, this method does not apply to other types of observability or nondeterministic systems. Second, we show that based on our observability graph, four different types of observability have been verified in BCNs, verification results have also been extended to PBNs, singular BCNs, and NFTSs. In addition, Moore’s partition also shows similarities between BCNs and linear time-invariant (LTI) control systems, e.g., smallest invariant dual subspaces of BNs containing a set of Boolean functions in BCNs vs unobservable subspaces of LTI control systems, the forms of quotient systems based on observability decomposition in both types of systems. However, there are essential differences between the two types of systems, e.g., “all plausible definitions of observability in LTI control systems turn out to be equivalent” (by Walter M. Wonham 1985), but there exist nonequivalent definitions of observability in BCNs; the quotient system based on observability decomposition always exists in an LTI control system, while a quotient system based on multiple-experiment observability decomposition does not always exist in a BCN.
X. Han, K. Zhang, J. Zhang, Z. Li, Z.Chen (2022) Strong current-state and initial-state opacity of discrete-event systems. Automatica, accepted
M. Khaled, K. Zhang, M. Zamani (2022) A framework for output-feedback symbolic control, IEEE Transactions on Automatic Control, accepted.