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  Subjects -> COMPUTER SCIENCE (Total: 1988 journals)
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COMPUTER SCIENCE (1153 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 14)
Abakós     Open Access   (Followers: 3)
Academy of Information and Management Sciences Journal     Full-text available via subscription   (Followers: 68)
ACM Computing Surveys     Hybrid Journal   (Followers: 22)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 9)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 11)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 12)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 3)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 20)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 9)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 16)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 13)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 54)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 1)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 6)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 7)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 7)
American Journal of Sensor Technology     Open Access   (Followers: 2)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 5)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 9)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 32)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 121)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 6)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access  
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 3)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 9)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Bioinformatics     Hybrid Journal   (Followers: 246)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 45)
British Journal of Educational Technology     Hybrid Journal   (Followers: 125)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 2)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 14)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access  
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 16)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 11)
Communication Theory     Hybrid Journal   (Followers: 19)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 53)
Communications of the Association for Information Systems     Open Access   (Followers: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 8)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 14)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 29)
Computer     Full-text available via subscription   (Followers: 84)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 7)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 14)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 11)
Computer Science Education     Hybrid Journal   (Followers: 12)
Computer Science Journal     Open Access   (Followers: 20)
Computer Science Master Research     Open Access   (Followers: 10)

        1 2 3 4 5 6 | Last

Journal Cover Automatica
  [SJR: 4.315]   [H-I: 188]   [9 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0005-1098
   Published by Elsevier Homepage  [3043 journals]
  • An adaptive order/state estimator for linear systems with non-integer
           time-varying order
    • Authors: S. Sepehr Tabatabaei; Heidar Ali Talebi; Mahdi Tavakoli
      Pages: 1 - 9
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): S. Sepehr Tabatabaei, Heidar Ali Talebi, Mahdi Tavakoli
      This paper proposes the design of a simultaneous order estimator and state observer for non-integer time-varying order linear systems. Several lemmas and theorems pertaining to the stability of variable order systems are provided first. Next, a theorem proposes an order/state estimator for linear variable order systems. Then, a simulation study is presented to verify the theoretical results.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.042
      Issue No: Vol. 84 (2017)
  • On algorithms for state feedback stabilization of Boolean control networks
    • Authors: Jinling Liang; Hongwei Chen; Yang Liu
      Pages: 10 - 16
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Jinling Liang, Hongwei Chen, Yang Liu
      This paper deals with the algorithms for state feedback stabilization of Boolean control networks (BCNs). By resorting to the semi-tensor product (STP) technique, the labelled digraph that can be used to completely characterize the dynamics of BCNs is derived, which leads to an equivalent graphical description for the stabilization of BCNs. What is more interesting is the fact that the existence of a state feedback control law stabilizing the BCN to some given equilibrium point can be characterized in terms of its spanning in-tree. Consequently, two in-tree search algorithms, namely, the breadth-first search and the depth-first search, are proposed to design the state feedback stabilizing law when global stabilization is feasible. Besides, some basic properties about the tree-search algorithms are addressed. A biological example is employed to illustrate the applicability and usefulness of the developed algorithms.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.040
      Issue No: Vol. 84 (2017)
  • A Tensor Network Kalman filter with an application in recursive MIMO
           Volterra system identification
    • Authors: Kim Batselier; Zhongming Chen; Ngai Wong
      Pages: 17 - 25
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Kim Batselier, Zhongming Chen, Ngai Wong
      This article introduces a Tensor Network Kalman filter, which can estimate state vectors that are exponentially large without ever having to explicitly construct them. The Tensor Network Kalman filter also easily accommodates the case where several different state vectors need to be estimated simultaneously. The key lies in rewriting the standard Kalman equations as tensor equations and then implementing them using Tensor Networks, which effectively transforms the exponential storage cost and computational complexity into a linear one. We showcase the power of the proposed framework through an application in recursive nonlinear system identification of high-order discrete-time multiple-input multiple-output (MIMO) Volterra systems. The identification problem is transformed into a linear state estimation problem wherein the state vector contains all Volterra kernel coefficients and is estimated using the Tensor Network Kalman filter. The accuracy and robustness of the scheme are demonstrated via numerical experiments, which show that updating the Kalman filter estimate of a state vector of length 109 and its covariance matrix takes about 0.007 s on a standard desktop computer in Matlab.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.019
      Issue No: Vol. 84 (2017)
  • Tensor Network alternating linear scheme for MIMO Volterra system
    • Authors: Kim Batselier; Zhongming Chen; Ngai Wong
      Pages: 26 - 35
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Kim Batselier, Zhongming Chen, Ngai Wong
      This article introduces two Tensor Network-based iterative algorithms for the identification of high-order discrete-time nonlinear multiple-input multiple-output (MIMO) Volterra systems. The system identification problem is rewritten in terms of a Volterra tensor, which is never explicitly constructed, thus avoiding the curse of dimensionality. It is shown how each iteration of the two identification algorithms involves solving a linear system of low computational complexity. The proposed algorithms are guaranteed to monotonically converge and numerical stability is ensured through the use of orthogonal matrix factorizations. The performance and accuracy of the two identification algorithms are illustrated by numerical experiments, where accurate degree-10 MIMO Volterra models are identified in about 1 s using Matlab on a 3.3 GHz quad-core desktop computer with 16 GB RAM.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.033
      Issue No: Vol. 84 (2017)
  • Function perturbations on singular Boolean networks
    • Authors: Yang Liu; Bowen Li; Hongwei Chen; Jinde Cao
      Pages: 36 - 42
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Yang Liu, Bowen Li, Hongwei Chen, Jinde Cao
      This paper is devoted to studying function perturbations on the transition matrix and topological structure of a singular Boolean network (SBN) via the semi-tensor product of matrices. First, the algebraic form of an SBN is given, and we discuss how the transition matrix of the SBN changes under function perturbations. Then the local uniqueness of solutions to the SBN is studied, under which the impacts of function perturbations on the topological structure are investigated. Finally, examples are given to show the effectiveness of the obtained results.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.035
      Issue No: Vol. 84 (2017)
  • Solvability conditions and design for state synchronization of multi-agent
    • Authors: Anton A. Stoorvogel; Ali Saberi; Meirong Zhang
      Pages: 43 - 47
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Anton A. Stoorvogel, Ali Saberi, Meirong Zhang
      This paper derives conditions on the agents for the existence of a protocol which achieves synchronization of homogeneous multi-agent systems (MAS) with partial-state coupling, where the communication network is directed and weighted. These solvability conditions are necessary and sufficient for single-input agents and sufficient for multi-input agents. The solvability conditions reveal that the synchronization problem is primarily solvable for two classes of agents. This first class consists of at most weakly unstable agents (i.e. agents have all eigenvalues in the closed left half plane) and the second class consists of at most weakly non-minimum-phase agents (i.e. agents have all zeros in the closed left half plane). Under our solvability condition, we provide in this paper a design, utilizing H ∞ optimal control.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.016
      Issue No: Vol. 84 (2017)
  • Adaptation, coordination, and local interactions via distributed
    • Authors: Dario Bauso
      Pages: 48 - 55
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Dario Bauso
      This paper investigates the relation between cooperation, competition, and local interactions in large distributed multi-agent systems. The main contribution is the game-theoretic problem formulation and solution approach based on the new framework of distributed approachability, and the study of the convergence properties of the resulting game model. Approachability theory is the theory of two-player repeated games with vector payoffs, and distributed approachability is here presented for the first time as an extension to the case where we have a team of agents cooperating against a team of adversaries under local information and interaction structure. The game model turns into a nonlinear differential inclusion, which after a proper design of the control and disturbance policies, presents a consensus term and an exogenous adversarial input. Local interactions enter into the model through a graph topology and the corresponding graph-Laplacian matrix. Given the above model, we turn the original questions on cooperation, competition, and local interactions, into convergence properties of the differential inclusion. In particular, we prove convergence and exponential convergence conditions around zero under general Markovian strategies. We illustrate our results in the case of decentralized organizations with multiple decision-makers.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.017
      Issue No: Vol. 84 (2017)
  • Pareto suboptimal controllers in multi-objective disturbance attenuation
    • Authors: Dmitry V. Balandin; Mark M. Kogan
      Pages: 56 - 61
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Dmitry V. Balandin, Mark M. Kogan
      A multi-objective disturbance attenuation problem is considered as a novel framework for control and filtering problems under multiple exogenous disturbances. There are N potentially possible disturbance inputs of a system on each of which may act a disturbance from a certain class. A disturbance attenuation level is defined for each channel as an induced norm of the operator mapping signals of the corresponding class to the objective output of the system. Necessary conditions of the Pareto optimality are derived. It is established that the optimal solutions with respect to a multi-objective cost parameterized by weights from an N -dimensional simplex are Pareto suboptimal solutions and their relative losses compared to the Pareto optimal ones do not exceed 1 − N ∕ N . These results are extended to the case when the disturbances acting on different inputs are combined into coalitions. The approach is applied to multiple classes of L 2 -bounded and impulsive disturbances for which the H ∞ ∕ γ 0 optimal controllers as the Pareto suboptimal solutions are synthesized in terms of linear matrix inequalities (LMIs). Illustrative examples demonstrate the effectiveness of the approach proposed.

      PubDate: 2017-08-03T08:07:31Z
      DOI: 10.1016/j.automatica.2017.06.041
      Issue No: Vol. 84 (2017)
  • Moment-based analysis of stochastic hybrid systems with renewal
    • Authors: Mohammad Soltani; Abhyudai Singh
      Pages: 62 - 69
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Mohammad Soltani, Abhyudai Singh
      Stochastic Hybrid Systems (SHS) constitute an important class of mathematical models that integrate discrete stochastic events with continuous dynamics. The time evolution of statistical moments is generally not closed for SHS, in the sense that the time derivative of the lower-order moments depends on higher-order moments. Here, we identify an important class of SHS where moment dynamics is automatically closed, and hence moments can be computed exactly by solving a system of coupled differential equations. This class is referred to as linear time-triggered SHS (TTSHS), where the state evolves according to a linear dynamical system. Stochastic events occur at discrete times and the intervals between them are independent random variables that follow a general class of probability distributions. Moreover, whenever the event occurs, the state of the SHS changes randomly based on a probability distribution. Our approach relies on embedding a Markov chain based on phase-type processes to model timing of events, and showing that the resulting system has closed moment dynamics. Interestingly, we identify a subclass of linear TTSHS, where the first and second-order moments depend only on the mean time interval between events, and invariant of higher-order statistics of event timing. TTSHS are used to model examples drawn from cell biology and nanosensors, providing novel insights into how noise is regulated in these systems.

      PubDate: 2017-08-03T08:07:31Z
      DOI: 10.1016/j.automatica.2017.07.001
      Issue No: Vol. 84 (2017)
  • ℓ2-stability: The cases of infinite dimensional discrete autonomous
           systems and 2-D autonomous systems
    • Authors: Chirayu D. Athalye; Debasattam Pal; Harish K. Pillai
      Pages: 70 - 78
      Abstract: Publication date: October 2017
      Source:Automatica, Volume 84
      Author(s): Chirayu D. Athalye, Debasattam Pal, Harish K. Pillai
      In this paper, we analyze ℓ 2 -stability of infinite dimensional discrete autonomous systems given in a state space form with state transition matrix being a Laurent polynomial matrix A ( σ , σ − 1 ) in the shift operator σ . We give sufficient conditions and necessary conditions for ℓ 2 -stability of such systems. We then use the theory of ℓ 2 -stability, thus developed, to analyze ℓ 2 -stability of discrete 2-D autonomous systems. We achieve this by showing how a discrete 2-D autonomous system can be converted to an equivalent infinite dimensional state space discrete autonomous system, where the state transition matrix turns out to be a Laurent polynomial matrix in the shift operator. Finally, we provide some easy-to-check numerical tests for ℓ 2 -stability of the above-mentioned type of systems.

      PubDate: 2017-08-03T08:07:31Z
      DOI: 10.1016/j.automatica.2017.06.028
      Issue No: Vol. 84 (2017)
  • Asymptotic stability in probability for Stochastic Boolean Networks
    • Authors: Corrado Possieri; Andrew R. Teel
      Pages: 1 - 9
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Corrado Possieri, Andrew R. Teel
      In this paper, a new class of Boolean networks, called Stochastic Boolean Networks, is presented. These systems combine some features of the classical deterministic Boolean networks (the state variables admit two operation levels, either 0 or 1) and of Probabilistic Boolean Networks (at each time instant the transition map is selected through a random process), enriching the set of admissible dynamical behaviors, thanks to the set-valued nature of the transition map. Necessary and sufficient Lyapunov conditions are given to guarantee global asymptotic stability (resp., global asymptotic stability in probability) of a given set for a deterministic Boolean network with set–valued transition map (resp., for a Stochastic Boolean Network). A constructive procedure to compute a Lyapunov function (resp., stochastic Lyapunov function) relative to a given set for a deterministic Boolean network with set–valued transition map (resp., Stochastic Boolean Network) is reported.

      PubDate: 2017-05-28T07:15:20Z
      DOI: 10.1016/j.automatica.2017.04.040
      Issue No: Vol. 83 (2017)
  • Symbolic control design for monotone systems with directed specifications
    • Authors: Eric S. Kim; Murat Arcak; Sanjit A. Seshia
      Pages: 10 - 19
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Eric S. Kim, Murat Arcak, Sanjit A. Seshia
      We study the control of monotone systems when the objective is to maintain trajectories in a directed set (that is, either upper or lower set) within a signal space. We define the notion of a directed alternating simulation relation and show how it can be used to tackle common bottlenecks in abstraction-based controller synthesis. First, we develop sparse abstractions to speed up the controller synthesis procedure by reducing the number of transitions. Next, we enable a compositional synthesis approach by employing directed assume–guarantee contracts between systems. In a vehicle traffic network example, we synthesize an intersection signal controller while dramatically reducing runtime and memory requirements compared to previous approaches.

      PubDate: 2017-06-02T05:20:13Z
      DOI: 10.1016/j.automatica.2017.04.060
      Issue No: Vol. 83 (2017)
  • On optimization of stochastic max–min-plus-scaling systems—An
           approximation approach
    • Authors: Samira S. Farahani; Ton van den Boom; Bart De Schutter
      Pages: 20 - 27
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Samira S. Farahani, Ton van den Boom, Bart De Schutter
      A large class of discrete-event and hybrid systems can be described by a max–min-plus-scaling (MMPS) model, i.e., a model in which the main operations are maximization, minimization, addition, and scalar multiplication. Accordingly, optimization of MMPS systems appears in different problems defined for discrete-event and hybrid systems. For a stochastic MMPS system, this optimization problem is computationally highly demanding as often numerical integration has to be used to compute the objective function. The aim of this paper is to decrease such computational complexity by applying an approximation method that is based on the moments of a random variable and that can be computed analytically.

      PubDate: 2017-06-07T07:31:30Z
      DOI: 10.1016/j.automatica.2017.05.001
      Issue No: Vol. 83 (2017)
  • Impulsive stabilization of a class of singular systems with time-delays
    • Authors: Wu-Hua Chen; Wei Xing Zheng; Xiaomei Lu
      Pages: 28 - 36
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Wu-Hua Chen, Wei Xing Zheng, Xiaomei Lu
      This paper deals with the impulsive stabilization problem for a class of linear singular systems with time-delays. The stabilization is achieved by only exerting impulsive action on the slow state variables. Two novel Lyapunov methods are presented to determine exponential stability of the impulsively controlled systems. For the case where the time-delay is unknown and may be time-varying, a Lyapunov–Razumikhin method is developed, in which the Razumikhin condition is constructed by exploiting the relation among the fast state variables, the slow state variables, and their initial values. For the case where the delay derivative is strictly less than 1, a descriptor type of impulse-time-dependent Lyapunov functional is introduced, which is discontinuous at impulse times but does not grow along the state trajectories by construction. By using a convex technique, the stability criteria are expressed in terms of linear matrix inequalities (LMIs). Then, the impulsive controllers can be designed in the framework of LMIs. The effectiveness and advantages of the proposed methods are confirmed through simulation results.

      PubDate: 2017-06-12T07:36:52Z
      DOI: 10.1016/j.automatica.2017.05.008
      Issue No: Vol. 83 (2017)
  • Exponential convergence of a distributed algorithm for solving linear
           algebraic equations
    • Authors: Ji Liu; A. Stephen Morse; Angelia Nedić; Tamer Başar
      Pages: 37 - 46
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Ji Liu, A. Stephen Morse, Angelia Nedić, Tamer Başar
      In a recent paper, a distributed algorithm was proposed for solving linear algebraic equations of the form A x = b assuming that the equation has at least one solution. The equation is presumed to be solved by m agents assuming that each agent knows a subset of the rows of the matrix A b , the current estimates of the equation’s solution generated by each of its neighbors, and nothing more. Neighbor relationships are represented by a time-dependent directed graph N ( t ) whose vertices correspond to agents and whose arcs characterize neighbor relationships. Sufficient conditions on N ( t ) were derived under which the algorithm can cause all agents’ estimates to converge exponentially fast to the same solution to A x = b . These conditions were also shown to be necessary for exponential convergence, provided the data about A b available to the agents is “non-redundant”. The aim of this paper is to relax this “non-redundant” assumption. This is accomplished by establishing exponential convergence under conditions which are the weakest possible for the problem at hand; the conditions are based on a new notion of graph connectivity. An improved bound on the convergence rate is also derived.

      PubDate: 2017-06-07T07:31:30Z
      DOI: 10.1016/j.automatica.2017.05.004
      Issue No: Vol. 83 (2017)
  • Filtering S-coupled algebraic Riccati equations for discrete-time Markov
           jump systems
    • Authors: Oswaldo Luiz do Valle Costa; Danilo Zucolli Figueiredo
      Pages: 47 - 57
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Oswaldo Luiz do Valle Costa, Danilo Zucolli Figueiredo
      This paper deals with a set of S -coupled algebraic Riccati equations that arises in the study of filtering of discrete-time linear jump systems with the Markov chain in a general Borel space S . By S -coupled it is meant that the algebraic Riccati equations are coupled via an integral over S . Conditions for the existence and uniqueness of a positive semi-definite solution to the filtering S -coupled algebraic Riccati equations are obtained in terms of the concepts of stochastic detectability and stochastic stabilizability. This result is then applied to solve the infinite horizon minimum mean square linear Markov jump filtering problem. The obtained results generalize previous ones in the literature, which considered only the case of the Markov chain taking values in a finite state space.

      PubDate: 2017-06-07T07:31:30Z
      DOI: 10.1016/j.automatica.2017.05.007
      Issue No: Vol. 83 (2017)
  • Properties and stability analysis of discrete-time negative imaginary
    • Authors: Mei Liu; Junlin Xiong
      Pages: 58 - 64
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Mei Liu, Junlin Xiong
      This paper is concerned with discrete-time negative imaginary (DT-NI) functions. First, a new definition of DT-NI functions is introduced. Then, by means of the relations between discrete-time positive real and DT-NI functions, two different versions of DT-NI lemmas are established to characterize the DT-NI properties based on state-space realizations. Also, a necessary and sufficient condition is presented to guarantee the internal stability of positive feedback interconnected DT-NI systems. Meanwhile, some other properties of DT-NI functions are studied. Several numerical examples are presented to illustrate the main results of this paper. Compared to the previous results, our results remove the symmetric assumption in rational case.

      PubDate: 2017-06-07T07:31:30Z
      DOI: 10.1016/j.automatica.2017.05.006
      Issue No: Vol. 83 (2017)
  • Maximum delay bounds of linear systems under delay independent truncated
           predictor feedback
    • Authors: Yusheng Wei; Zongli Lin
      Pages: 65 - 72
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Yusheng Wei, Zongli Lin
      In a predictor feedback law for a linear system with input delay, the future state is predicted as the state solution of the linear system. The zero input solution contains the transition matrix. The zero state solution gives rise to the distributed nature of the feedback law. In a 2007 IEEE TAC paper, it is established that, when the system is not exponentially unstable, low gain feedback can be designed such that the predictor feedback law, with the distributed term truncated, still achieves stabilization for an arbitrarily large delay. Furthermore, in the absence of purely imaginary poles, the transition matrix in the truncated predictor feedback (TPF) can be safely dropped, resulting in a delay independent TPF law, which is simply a delay independent linear state feedback. In this paper, we first construct an example to show that, in the presence of purely imaginary poles, the linear delay independent TPF in general cannot stabilize the system for an arbitrarily large delay. By using the Lyapunov–Krasovskii Stability Theorem, we derive a bound on the delay under which the delay independent truncated predictor feedback law achieves stabilization for a general system that may be exponentially unstable.

      PubDate: 2017-06-12T07:36:52Z
      DOI: 10.1016/j.automatica.2017.05.003
      Issue No: Vol. 83 (2017)
  • Supervised control of buck-boost converters for aeronautical applications
    • Authors: Alberto Cavallo; Giacomo Canciello; Beniamino Guida
      Pages: 73 - 80
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Alberto Cavallo, Giacomo Canciello, Beniamino Guida
      Recent MEA (More Electric Aircraft) concepts require new approaches to design and management of the electric system onboard. Bidirectional Buck-Boost Converter Units (BBCU’s) used like bridges between power buses with different voltage require intelligent supervisory control for autonomous selection of operating modes. In this paper at low-level, sliding manifold-based strategies are employed to track desired current references, or to recover from overload within a prescribed time. At a higher level, three working modes are defined, (Buck-, Boost- and Intermediate-Mode), and scheduled by a high-level supervisory strategy. Stability proofs of the overall strategy require estimates of the Region of Attraction (ROA) for each controller, that are discussed in the paper. A typical aeronautic scenario is presented, with standard operating conditions followed by two types of overloads (the second more severe than the first) and finally a return to standard condition. Detailed numerical simulations show the effectiveness of the proposed novel control strategy in terms of stability and performance of the smart converter.

      PubDate: 2017-06-16T07:37:50Z
      DOI: 10.1016/j.automatica.2017.05.005
      Issue No: Vol. 83 (2017)
  • A framework for multivariable algebraic loops in linear anti-windup
    • Authors: Ambrose Adebayo Adegbege; William Paul Heath
      Pages: 81 - 90
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Ambrose Adebayo Adegbege, William Paul Heath
      This brief paper addresses the implementation and well-posedness aspects of multivariable algebraic loops which arise naturally in many anti-windup control schemes. Using the machinery of linear complementarity problems, a unified framework is developed for establishing well-posedness of such algebraic loops. Enforcing well-posedness is reduced to a linear matrix inequality feasibility problem that can be solved during the anti-windup design stage. Several existing anti-windup implementations appear as special cases of the unified framework presented in this brief paper.

      PubDate: 2017-06-16T07:37:50Z
      DOI: 10.1016/j.automatica.2017.05.009
      Issue No: Vol. 83 (2017)
  • Extremum seeking for dynamic maps using Lie brackets and singular
    • Authors: Hans-Bernd Dürr; Miroslav Krstić; Alexander Scheinker; Christian Ebenbauer
      Pages: 91 - 99
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Hans-Bernd Dürr, Miroslav Krstić, Alexander Scheinker, Christian Ebenbauer
      We introduce a framework for the analysis of extremum seeking systems for dynamic maps based on Lie bracket approximations and singular perturbation theory. Using the introduced framework, we provide an extremum seeking regulator for a unicycle and prove its stability properties.

      PubDate: 2017-06-16T07:37:50Z
      DOI: 10.1016/j.automatica.2017.05.002
      Issue No: Vol. 83 (2017)
  • Étale backstepping for control Lyapunov function design on manifold
    • Authors: Hisakazu Nakamura; Yasuyuki Satoh
      Pages: 100 - 107
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Hisakazu Nakamura, Yasuyuki Satoh
      Backstepping is one of the most popular nonlinear controller and differentiable control Lyapunov function (CLF) design techniques. However, for asymptotic stabilization of systems defined on noncontractible manifolds, there exists no differentiable CLF; the semiconcave CLF design problem based on the backstepping has not been discussed. In this paper, we propose a backstepping based controller design method for asymptotic stabilization of systems defined on noncontractible manifolds. In the method, we design a controller and a CLF on an étale space. Then, we obtain a semiconcave CLF on the original space by the minimum projection method. The effectiveness of the proposed method is confirmed by computer simulation.

      PubDate: 2017-06-22T07:41:50Z
      DOI: 10.1016/j.automatica.2017.05.010
      Issue No: Vol. 83 (2017)
  • Drift counteraction optimal control for deterministic systems and
           enhancing convergence of value iteration
    • Authors: Robert A.E. Zidek; Ilya V. Kolmanovsky
      Pages: 108 - 115
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Robert A.E. Zidek, Ilya V. Kolmanovsky
      The paper treats a class of optimal control problems for deterministic nonlinear discrete-time systems with the objective of maximizing the time or total yield until prescribed constraints are violated. Such problems are referred to as drift counteraction optimal control (DCOC) problems as the corresponding control policy may be viewed as optimally counteracting drift imposed by disturbances or system dynamics. We derive conditions for the existence of an optimal solution. The optimal control policy is characterized by the value function and a new algorithm based on proportional feedback is presented that obtains the value function faster than conventional dynamic programming algorithms. In addition, an approximate dynamic programming (ADP) approach using Gaussian process regression is formulated based on the new algorithm. Two numerical examples are reported, a time maximization problem for a van der Pol oscillator and a satellite life extension problem.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.015
      Issue No: Vol. 83 (2017)
  • Optimal tradeoff between instantaneous and delayed neighbor information in
           consensus algorithms
    • Authors: Weiguo Xia; Ziyang Meng; Guodong Shi; Karl Henrik Johansson
      Pages: 116 - 123
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Weiguo Xia, Ziyang Meng, Guodong Shi, Karl Henrik Johansson
      We consider a distributed consensus problem over a network, where at each time instant every node receives two pieces of information from disjoint neighboring sets: a weighted average of current states of neighbors from a primary network, and a weighted average of one-hop delayed states of neighbors from a secondary network. The proposed algorithm makes each node update its state to a weighted average of these individual averages. We show that convergence to consensus is guaranteed with non-trivial weights. We also present an explicit formula for the weights allocated to each piece of the information for the optimal rate of convergence, when the secondary network is the complement of the primary network. Finally numerical examples are given to explore the case when the neighbor sets of the agents do not cover the whole network.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.021
      Issue No: Vol. 83 (2017)
  • Adaptive asymptotic control of multivariable systems based on a
           one-parameter estimation approach
    • Authors: Ci Chen; Changyun Wen; Zhi Liu; Kan Xie; Yun Zhang; C.L. Philip Chen
      Pages: 124 - 132
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Ci Chen, Changyun Wen, Zhi Liu, Kan Xie, Yun Zhang, C.L. Philip Chen
      Multivariable adaptive control is an important and challenging research area, where it usually requires designing adaptive laws to estimate a number of unknown parameters. Hence, this process may excessively consume limitedly available computational resources and large amount of computational time, which may degrade system performances, particularly for the case of online updating of parameter estimates. Thus reducing the number of parameters to be estimated is a promising way to solve the problem. The state-of-the-art result in the area is to update just one adaptive parameter. However, the tracking errors are only ensured bounded and thus the resulting closed-loop system is not asymptotically stable. Hence, a question that arises is whether such a result of non-zero tracking errors is the price paid for reducing the number of updating parameters. Up to now, there is still no answer to this question. In this paper, we address such an issue and realize asymptotic stability with online estimation of just one parameter. To achieve such a goal, a novel dynamic loop gain function based approach is proposed to incorporate with the backstepping control design procedure, which enables us to solve the algebraic loop problem caused by all the existing traditional Nussbaum function based approaches and thus establish system stability. A bound for the tracking error is explicitly established in terms of L 2 norm, which helps improve the transient performance by selecting the control parameters. Moreover, guaranteed by the Barbalat’s Lemma, the tracking error is further ensured to approach zero asymptotically. Finally, simulation examples are conducted to testify the effectiveness of the proposed approach.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.03.003
      Issue No: Vol. 83 (2017)
  • On the robustness of the Bayes and Wiener estimators under model
    • Authors: Mattia Zorzi
      Pages: 133 - 140
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Mattia Zorzi
      This paper deals with the robust estimation problem of a signal given noisy observations. We assume that the actual statistics of the signal and observations belong to a ball about the nominal statistics. This ball is formed by placing a bound on a suitable divergence (or distance) between the actual and the nominal statistics. Then, the robust estimator is obtained by minimizing the mean square error according to the least favorable statistics in that ball. Therefore, we obtain a divergence-based minimax approach to robust estimation. Choosing a set of divergences, called Tau divergence family, we show that the Bayes estimator based on the nominal statistics is the optimal solution. Moreover, in the dynamic case, the optimal offline estimator is the noncausal Wiener filter based on the nominal statistics.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.005
      Issue No: Vol. 83 (2017)
  • Robustification of sample-and-hold stabilizers for control-affine
           time-delay systems
    • Authors: Mario Di Ferdinando; Pierdomenico Pepe
      Pages: 141 - 154
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Mario Di Ferdinando, Pierdomenico Pepe
      This paper deals with the stabilization in the sample-and-hold sense of nonlinear, control affine, retarded systems, affected by actuation disturbances and observation errors. Input-to-state stability redesign methods are used in order to design a new sampled-data controller. It is shown that stabilization in the sample-and-hold sense can be preserved by means of this new controller, regardless of the above disturbances and errors. It is assumed that both actuator disturbance and observation error are bounded, and the (arbitrary) bounds are known a-priori. It is moreover assumed that the observation errors do not affect or affect marginally the new control term obtained by input-to-state stability redesign. Simulations on a continuous stirred tank reactor with recycle validate the theoretical results.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.029
      Issue No: Vol. 83 (2017)
  • Pursuing an evader through cooperative relaying in multi-agent
           surveillance networks
    • Authors: Sheng-Li Du; Xi-Ming Sun; Ming Cao; Wei Wang
      Pages: 155 - 161
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Sheng-Li Du, Xi-Ming Sun, Ming Cao, Wei Wang
      We provide a distributed control strategy for each mobile agent in a surveillance network in the plane to cooperatively pursue an evader. The pursuit task is relayed from one agent to another when the evader crosses the boundary of the Voronoi regions divided according to the agents’ positions. The dynamics of the resulted cooperative relay-pursuit network are described by a novel model of impulsive systems. As a result, to guarantee the stability of the closed-loop network system, the controllers’ gains are chosen effectively using the solution of an algebraic Riccati equation. The proof of the stability is based on the construction of a switched Lyapunov function. We also show that the proposed controller is able to deal with delays if some sufficient conditions in the form of a set of linear inequalities are satisfied. A numerical example is provided to validate the performance of the proposed controller.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.022
      Issue No: Vol. 83 (2017)
  • Convergence rate analysis of distributed optimization with projected
           subgradient algorithm
    • Authors: Shuai Liu; Zhirong Qiu; Lihua Xie
      Pages: 162 - 169
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Shuai Liu, Zhirong Qiu, Lihua Xie
      In this paper, we revisit the consensus-based projected subgradient algorithm proposed for a common set constraint. We show that the commonly adopted non-summable and square-summable diminishing step sizes of subgradients can be relaxed to be only non-summable, if the constrained optimum set is bounded. More importantly, for a strongly convex aggregate cost with different types of step sizes, we provide a systematical analysis to derive the asymptotic upper bound of convergence rates in terms of the optimum residual, and select the best step sizes accordingly. Our result shows that a convergence rate of O ( 1 ∕ k ) can be achieved with a step size O ( 1 ∕ k ) .

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.011
      Issue No: Vol. 83 (2017)
  • Output and error feedback regulator designs for linear
           infinite-dimensional systems
    • Authors: Xiaodong Xu; Stevan Dubljevic
      Pages: 170 - 178
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Xiaodong Xu, Stevan Dubljevic
      This manuscript addresses the output regulation problem for linear distributed parameter systems (DPSs) with bounded input and unbounded output operators. We introduce novel methods for the design of the output feedback and error feedback regulators. In the output feedback regulator design, the measurements available for the regulator do not belong to the set of controlled outputs. The proposed output feedback regulator with the injection of the measurement y m ( t ) and reference y r ( t ) can realize both the plant and the exosystem states estimation, disturbance rejection and reference signal tracking, simultaneously. Moreover, new design approach provides an alternative choice for seeking the output injection gain in a traditional error feedback regulator design. The regulator parameters are easily configured to solve the output regulation problems, and to ensure the stability of the closed-loop systems. The results are demonstrated via computer simulation in two types of representative systems: the parabolic partial differential equation (PDE) system and the first order hyperbolic PDE system.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.003
      Issue No: Vol. 83 (2017)
  • Power control in Wireless Cellular Networks with a time-varying delay
    • Authors: Hamed Samie; Emmanuel Moulay; Patrick Coirault; Rodolphe Vauzelle
      Pages: 179 - 185
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Hamed Samie, Emmanuel Moulay, Patrick Coirault, Rodolphe Vauzelle
      Uplink transmission power control is an essential task in Wireless Cellular Networks (WCNs) due to the resource limitation of the Mobile Stations (MSs). One remaining problem is the effect of the delay caused by measuring the signal strength and decision making in the Inner-Loop Power Control (ILPC). In this article, we develop the Potential Feedback Controller (PFC) for a linear scalar discrete-time system with disturbance in order to take into account an unknown bounded time-varying input delay for uplink ILPC. The main interest of the PFC is to treat easily a stabilization problem with a constraint on the state space by using a nonlinear feedback control with a short computation time. Simulations illustrate that by applying the PFC, the communication connectivity is ensured by maintaining the signal strength above a required limit.

      PubDate: 2017-07-03T09:22:55Z
      DOI: 10.1016/j.automatica.2017.06.034
      Issue No: Vol. 83 (2017)
  • Dynamical analysis of quantum linear systems driven by multi-channel
           multi-photon states
    • Authors: Guofeng Zhang
      Pages: 186 - 198
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Guofeng Zhang
      In this paper, we investigate the dynamics of quantum linear systems where the input signals are multi-channel multi-photon states, namely states determined by a definite number of photons superposed in multiple input channels. In contrast to most existing studies on separable input states in the literature, we allow the existence of quantum correlation (for example quantum entanglement) in these multi-channel multi-photon input states. Due to the prevalence of quantum correlations in the quantum regime, the results presented in this paper are very general. Moreover, the multi-channel multi-photon states studied here are reasonably mathematically tractable. Three types of multi-photon states are considered: (1) m photons superposed among m channels, (2) N photons superposed among m channels where N ≥ m , and (3) N photons superposed among m channels where N is an arbitrary positive integer. Formulae for intensities and states of output fields are derived. Examples are used to demonstrate the effectiveness of the results.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.002
      Issue No: Vol. 83 (2017)
  • Verification complexity of a class of observational properties for modular
           discrete events systems
    • Authors: Xiang Yin; Stéphane Lafortune
      Pages: 199 - 205
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Xiang Yin, Stéphane Lafortune
      A modular discrete event system is modeled by a set of module automata running synchronously. In this paper, we investigate the complexity of the verification problems of three different properties, diagnosability, predictability, and detectability, for partially-observed modular discrete event systems. We first show that deciding diagnosability for modular discrete event systems is PSPACE-complete when the number of modules is unbounded. Then we show that deciding predictability and detectability for modular discrete event systems are both PSPACE-hard problems. These results reveal that in order to verify these properties for the complete system, exploring the state space of the monolithic model may be unavoidable, in the worst case.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.013
      Issue No: Vol. 83 (2017)
  • State-of-Charge estimation from a thermal–electrochemical model of
           lithium-ion batteries
    • Authors: Shu-Xia Tang; Leobardo Camacho-Solorio; Yebin Wang; Miroslav Krstic
      Pages: 206 - 219
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Shu-Xia Tang, Leobardo Camacho-Solorio, Yebin Wang, Miroslav Krstic
      A thermal–electrochemical model of lithium-ion batteries is presented and a Luenberger observer is derived for State-of-Charge (SoC) estimation by recovering the lithium concentration in the electrodes. This first-principles based model is a coupled system of partial and ordinary differential equations, which is a reduced version of the Doyle–Fuller–Newman model. More precisely, the subsystem of Partial Differential Equations (PDEs) is the Single Particle Model (SPM) while the Ordinary Differential Equation (ODE) is a model for the average temperature in the battery. The observer is designed following the PDE backstepping method. Since some coefficients in the coupled ODE–PDE system are time-varying, this results in the time dependency of some coefficients in the kernel function system of the backstepping transformation and it is non-trivial to show well-posedness of the latter system. Adding thermal dynamics to the SPM serves a two-fold purpose: improving the accuracy of SoC estimation and keeping track of the average temperature which is a critical variable for safety management in lithium-ion batteries. Effectiveness of the estimation scheme is validated via numerical simulations.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.030
      Issue No: Vol. 83 (2017)
  • N-diagnosability for active on-line diagnosis in discrete event systems
    • Authors: Feng Lin; Le Yi Wang; Wen Chen; Leitao Han; Bin Shen
      Pages: 220 - 225
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Feng Lin, Le Yi Wang, Wen Chen, Leitao Han, Bin Shen
      In this paper, we investigate active on-line diagnosis in discrete event systems. Active diagnosis can be used for fault detection, fault localization, fault-tolerant control, among others. Discrete event systems are general models for complex manmade systems. For the active on-line diagnosis, we do not construct the entire diagnostic automaton off-line. Instead, we look N steps ahead to determine active diagnosability and calculate diagnostic strategies. Thus, we define active N -diagnosability and investigate the relation between active diagnosability and active N -diagnosability. We also develop an algorithm to check active N -diagnosability. If a system is actively N -diagnosable, the algorithm will also give the control that diagnoses the system. We show that there are significant computational advantages for using the on-line approach.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.004
      Issue No: Vol. 83 (2017)
  • Consensus dynamics with arbitrary sign-preserving nonlinearities
    • Authors: Jieqiang Wei; Anneroos R.F. Everts; M. Kanat Camlibel; Arjan J. van der Schaft
      Pages: 226 - 233
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Jieqiang Wei, Anneroos R.F. Everts, M. Kanat Camlibel, Arjan J. van der Schaft
      This paper studies consensus problems for multi-agent systems defined on directed graphs where the consensus dynamics involves general nonlinear and discontinuous functions. Sufficient conditions, only involving basic properties of the nonlinear functions and the topology of the underlying graph, are derived for the agents to converge to consensus.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.001
      Issue No: Vol. 83 (2017)
  • Spectral and structural properties of random interdependent networks
    • Authors: Ebrahim Moradi Shahrivar; Mohammad Pirani; Shreyas Sundaram
      Pages: 234 - 242
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Ebrahim Moradi Shahrivar, Mohammad Pirani, Shreyas Sundaram
      Random interdependent networks consist of a group of subnetworks where each edge between two different subnetworks is formed independently with probability p . In this paper, we investigate certain spectral and structural properties of such networks, with corresponding implications for certain variants of consensus and diffusion dynamics on those networks. We start by providing a characterization of the isoperimetric constant in terms of the inter-network edge formation probability p . We then analyze the algebraic connectivity of such networks, and provide an asymptotically tight rate of growth of this quantity for a certain range of inter-network edge formation probabilities. Next, we give bounds on the smallest eigenvalue of the grounded Laplacian matrix (obtained by removing certain rows and columns of the Laplacian matrix) of random interdependent networks for the case where the removed rows and columns correspond to one of the subnetworks. Finally, we study a property known as r -robustness, which is a strong indicator of the ability of a network to tolerate structural perturbations and dynamical attacks. Our results yield new insights into the structure and robustness properties of random interdependent networks.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.024
      Issue No: Vol. 83 (2017)
  • Time-varying feedback for regulation of normal-form nonlinear systems in
           prescribed finite time
    • Authors: Yongduan Song; Yujuan Wang; John Holloway; Miroslav Krstic
      Pages: 243 - 251
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Yongduan Song, Yujuan Wang, John Holloway, Miroslav Krstic
      While non-smooth approaches (including sliding mode control) provide explicit feedback laws that ensure finite-time stabilization but in terminal time that depends on the initial condition, fixed-time optimal control with a terminal constraint ensures regulation in prescribed time but lacks the explicit character in the presence of nonlinearities and uncertainties. In this paper we present an alternative to these approaches, which, while lacking optimality, provides explicit time-varying feedback laws that achieve regulation in prescribed finite time, even in the presence of non-vanishing (though matched) uncertain nonlinearities. Our approach employs a scaling of the state by a function of time that grows unbounded towards the terminal time and is followed by a design of a controller that stabilizes the system in the scaled state representation, yielding regulation in prescribed finite time for the original state. The achieved robustness to right-hand-side disturbances is not accompanied by robustness to measurement noise, which is also absent from all controllers that are nonsmooth or discontinuous at the origin.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.008
      Issue No: Vol. 83 (2017)
  • Boundary control of delayed ODE–heat cascade under actuator
    • Authors: Wen Kang; Emilia Fridman
      Pages: 252 - 261
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Wen Kang, Emilia Fridman
      In this paper, we consider boundary stabilization for a cascade of ODE–heat system with a time-varying state delay under actuator saturation. To stabilize the system, we design a state feedback controller via the backstepping method and find a bound on the domain of attraction. The latter bound is based on Lyapunov method, whereas the exponential stability conditions for the delayed cascaded system are derived by using Halanay’s inequality. Numerical examples illustrate the efficiency of the method.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.014
      Issue No: Vol. 83 (2017)
  • Robust stabilization of delayed neural fields with partial measurement and
    • Authors: Antoine Chaillet; Georgios Is. Detorakis; Stéphane Palfi; Suhan Senova
      Pages: 262 - 274
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Antoine Chaillet, Georgios Is. Detorakis, Stéphane Palfi, Suhan Senova
      Neural fields are integro-differential equations describing spatiotemporal activity of neuronal populations. When considering finite propagation speed of action potentials, neural fields are affected by space-dependent delays. In this paper, we provide conditions under which such dynamics can be robustly stabilized by a proportional feedback acting only on a portion of the neuronal population and by relying on measurements of this subpopulation only. To that aim, in line with recent works, we extend the concept of input-to-state stability (ISS) to generic nonlinear delayed spatiotemporal dynamics and provide a small-gain result relying on Lyapunov–Krasovskii functionals. Exploiting the robustness properties induced by ISS, we provide conditions under which a uniform control signal can be used for the whole controlled subpopulation and we analyze the robustness of the proposed strategy to measurement and actuation delays. These theoretical findings are compared to simulation results in a model of pathological oscillations generation in Parkinson’s disease.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.05.011
      Issue No: Vol. 83 (2017)
  • Kernel-based identification of Wiener–Hammerstein system
    • Authors: Grzegorz Mzyk; Paweł Wachel
      Pages: 275 - 281
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Grzegorz Mzyk, Paweł Wachel
      This paper addresses the problem of Wiener–Hammerstein (LNL) system identification. We present two estimates, which recover the static nonlinear characteristic and the linear dynamic blocks separately. Both algorithms are based on kernel preselection of data and application of local least squares and cross-correlation techniques. Formal proofs of consistency are derived under very mild a priori restrictions imposed on the input excitation and system characteristics. In particular, the input need not be Gausssian, and a wide (nonparametric) class of nonlinear characteristics is admitted. Finally, we propose a universal multi-stage identification strategy which allows to split the resulting linear model into two separate blocks. We also present a simple simulation example to illustrate the behavior of the method in practice.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.038
      Issue No: Vol. 83 (2017)
  • Fixed-structure LPV-IO controllers: An implicit representation based
    • Authors: Simon Wollnack; Hossam Seddik Abbas; Roland Tóth; Herbert Werner
      Pages: 282 - 289
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Simon Wollnack, Hossam Seddik Abbas, Roland Tóth, Herbert Werner
      In this note, novel linear matrix inequality (LMI) analysis conditions for the stability of linear parameter-varying (LPV) systems in input–output (IO) representation form are proposed together with bilinear matrix inequality (BMI) conditions for fixed-structure LPV-IO controller synthesis. Both the LPV-IO plant model and the controller are assumed to depend affinely and statically on the scheduling variables. By using an implicit representation of the plant and the controller interaction, an exact representation of the closed-loop behavior with affine dependence on the scheduling variables is achieved. This representation allows to apply Finsler’s Lemma for deriving exact stability as well as exact quadratic performance conditions. A DK-iteration based solution is carried out to synthesize the controller. The main results are illustrated by a numerical example.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.009
      Issue No: Vol. 83 (2017)
  • Output feedback boundary control of 2×2 semilinear hyperbolic systems
    • Authors: Timm Strecker; Ole Morten Aamo
      Pages: 290 - 302
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Timm Strecker, Ole Morten Aamo
      We consider the control and state estimation of a class of 2 × 2 semilinear hyperbolic systems with actuation and sensing collocated at one boundary. Our approach exploits the dynamics on the characteristic lines of the hyperbolic system. The control method using full-state feedback can be used for both stabilization of an equilibrium and tracking at an arbitrary point in the domain. The control objective is achieved globally in minimum time. A Lyapunov function is constructed to prove exponential convergence in the spatial supremum norm. For linear systems, the control input can be written explicitly as the inner product of kernels with the state, and turns out to be equivalent to the control input obtained from previously known backstepping methods. The observer achieves exact state estimation also in minimum time and, combined with the state-feedback controller, solves the output feedback control problem. The performance is demonstrated in a numerical example.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.026
      Issue No: Vol. 83 (2017)
  • Further results on feedback stabilization control design of Boolean
           control networks
    • Authors: Haitao Li; Yuzhen Wang
      Pages: 303 - 308
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Haitao Li, Yuzhen Wang
      This paper investigates designing all possible feedback stabilizers for Boolean control networks (BCNs). Some new results on the feedback stabilization control design of BCNs are presented. The main tool used in the paper is the semi-tensor product of matrices. First, the complete family of reachable sets is defined for BCNs. Then it is shown that all the complete families of reachable sets determine all possible state feedback stabilizers. Second, using all the complete families of reachable sets, all possible state feedback stabilizers are obtained. Third, a necessary and sufficient condition is obtained for the existence of output feedback stabilizers. Based on this condition, all possible output feedback stabilizers are designed for BCNs. Finally, the obtained new results are applied to the regulation of the lactose operon in Escherichia coli.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.043
      Issue No: Vol. 83 (2017)
  • Semi-explicit MPC based on subspace clustering
    • Authors: Gregor Goebel; Frank Allgöwer
      Pages: 309 - 316
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Gregor Goebel, Frank Allgöwer
      This paper presents a new strategy of simplifying the online computations in linear model predictive control (MPC). Employing a specific type of state dependent parameterization for the optimization variable in MPC, advantages of explicit MPC are combined with those of online optimization based MPC into an efficient MPC scheme. The parameterization is computed offline applying a tailored subspace clustering algorithm to training data consisting of states and corresponding solutions to the MPC optimization problem. It is then refined to guarantee feasibility of the parameterized optimization. During the offline design phase, complexity of the parameterization can be adjusted and control performance can be traded off against online computational effort and storage requirements. Numerical examples evaluate the presented methods and illustrate their benefits.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.036
      Issue No: Vol. 83 (2017)
  • On the efficient low cost procedure for estimation of high-dimensional
           prediction error covariance matrices
    • Authors: Hong Son Hoang; Remy Baraille
      Pages: 317 - 330
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Hong Son Hoang, Remy Baraille
      A simple, efficient algorithm is proposed for estimating the prediction error covariance matrix which plays the key role for successful state estimation in very high dimensional systems. The main results are obtained by introducing the hypothesis on the separability of vertical and horizontal structure of the error covariance matrix and its parameterization. A new parameter optimization problem is formulated which is closely related to the Nearest Kronecker Problem (NKP). This allows to estimate optimally the unknown parameters of the structured parametrized ECM as well as to approach numerically the solution of the traditional NKP in a simple and efficient way. The algorithm for the state estimation will be detailed. The results from experiments on parameter and state estimation problems, for both moderate and high dimensional numerical models, demonstrate a high effectiveness of the proposed filtering approach.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.018
      Issue No: Vol. 83 (2017)
  • Trajectory tracking for a class of contractive port Hamiltonian systems
    • Authors: Abolfazl Yaghmaei; Mohammad Javad Yazdanpanah
      Pages: 331 - 336
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Abolfazl Yaghmaei, Mohammad Javad Yazdanpanah
      In this paper, a class of contractive port Hamiltonian systems is characterized. Having wide range of applications, Port Hamiltonian systems match IDA-PBC (Interconnection and Damping Assignment Passivity Based Control) framework, as a powerful design technique. Through utilization of contraction properties of port Hamiltonian systems, an approach which stems from IDA-PBC is proposed for tracker design of such systems. In the line of showing the applicability and superiority of the proposed approach, it is applied to an electromechanical system, i.e., magnetic levitation.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.039
      Issue No: Vol. 83 (2017)
  • Stabilization of MISO fractional systems with delays
    • Authors: Le Ha Vy Nguyen; Catherine Bonnet
      Pages: 337 - 344
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Le Ha Vy Nguyen, Catherine Bonnet
      We consider multi-input single-output (MISO) fractional systems of commensurate fractional orders with different input or output delays. We derive explicit expressions of left and right coprime factorizations over H ∞ and of the associated Bézout factors of the transfer matrix of the systems. These factors allow the construction of the Youla–Kučera parametrization of the set of stabilizing controllers which guarantee the internal stability of the closed-loop systems.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.06.032
      Issue No: Vol. 83 (2017)
  • Optimal control of uncertain nonlinear quadratic systems
    • Authors: Alessio Merola; Carlo Cosentino; Domenico Colacino; Francesco Amato
      Pages: 345 - 350
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Alessio Merola, Carlo Cosentino, Domenico Colacino, Francesco Amato
      This paper addresses the problem of robust and optimal control for the class of nonlinear quadratic systems subject to norm-bounded parametric uncertainties and disturbances. By using an approach based on the guaranteed cost control theory, a technique is proposed to design a state feedback controller ensuring for the closed-loop system: (i) the local exponential stability of the zero equilibrium point; (ii) the inclusion of a given region into the domain of exponential stability of the equilibrium point; (iii) the satisfaction of a guaranteed level of performance, in terms of boundedness of some optimality indexes. In particular, a sufficient condition for the existence of a state feedback controller satisfying a prescribed integral–quadratic index is provided, followed by a sufficient condition for the existence of a state feedback controller satisfying a given L 2 -gain disturbance rejection constraint. By the proposed design procedures, the optimal control problems dealt with here can be efficiently solved as Linear Matrix Inequality (LMI) optimization problems.

      PubDate: 2017-07-12T09:27:05Z
      DOI: 10.1016/j.automatica.2017.05.012
      Issue No: Vol. 83 (2017)
  • Peer-Assisted Individual Assessment in a multi-agent system
    • Authors: Wenjie Li; Francesca Bassi; Laura Galluccio; Michel Kieffer
      Pages: 351 - 360
      Abstract: Publication date: September 2017
      Source:Automatica, Volume 83
      Author(s): Wenjie Li, Francesca Bassi, Laura Galluccio, Michel Kieffer
      Consider a multi-agent system where agents perform a given task with different levels of ability. Agents are initially not aware of how well they perform in comparison with their peers, and are willing to self-assess. This scenario is relevant, e.g., in wireless sensor networks, or in crowdsensing applications, where devices with embedded sensing capabilities collaboratively collect data to characterize the environment: the global performance is very sensitive to the measurement accuracy, and agents providing outliers should restrain to participate. This paper presents a distributed algorithm enabling each agent to self-assess its own ability. The algorithm tracks the outcomes of a local comparison test performed by pairs of agents when they randomly meet, and able to gauge their relative level of ability. The dynamics of the proportions of agents with similar assessments are described using continuous-time state equations. The existence of an equilibrium is shown. Closed-form expressions for the various proportions of agents with similar assessments are provided at equilibrium. In simulations, a community of agents equipped with sensors, and trying to determine the performance of their equipment is considered. Simulation results show a good fitting with theoretical predictions.

      PubDate: 2017-07-23T22:45:25Z
      DOI: 10.1016/j.automatica.2017.06.031
      Issue No: Vol. 83 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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