List of English Publication

@article{VengertsevKimSeoShim13,

title = {Consensus of output-coupled high-order linear multi-agent systems under deterministic and Markovian switching networks},

author = {Dmitry Vengertsev and Hongkeun Kim and Jin Heon Seo and Hyungbo Shim},

doi = {10.1080/00207721.2013.835884},

issn = {0020-7721},

year  = {2013},

date = {2013-09-20},

journal = {International Journal of Systems Science},

volume = {46},

number = {10},

pages = {1790-1799},

abstract = {Consensus problem for high-order multi-agent systems is considered under deterministic and Markovian switching topologies. Only relative output information of agents is assumed to be available through the networks. First, a necessary and sufficient condition for achieving a consensus under a fixed communication network is presented. Based on this result and the stability of switched systems, a high-order multi-agent system with the proposed low-gain controller is shown to reach a consensus under deterministic switching network if the total time when the network is disconnected is, in some senses, smaller than the total time of the network being connected. Furthermore, the conditions sufficient for a high-order multi-agent system to reach an almost sure and mean-square consensus, under Markovian switching networks, are presented. Finally, illustrative examples are given to demonstrate the results.},

keywords = {Consensus, nonlinear},

pubstate = {published},

tppubtype = {article}

}

@article{LeeKimShim12,

title = {Disc Margins of the Discrete-time LQR and its Application to Consensus Problem},

author = {Jinyoung Lee and Jung-Su Kim and Hyungbo Shim},

doi = {10.1080/00207721.2011.555012},

year  = {2012},

date = {2012-10-01},

journal = {International Journal of Systems Science },

volume = {43},

number = {10},

pages = {1891-1900},

abstract = {This article presents a complex gain margin of discrete-time linear quadratic regulator (DLQR) and its application to a consensus problem of multi-agent higher order linear systems. Since the consensus problem can be converted into a robust control problem with perturbation expressed by complex numbers, and since the classical gain and phase margins are not enough to handle the current case, we study the so-called ‘disc margin’ which is somehow a combination of gain and phase margins. We first compute the disc margin of DLQR controller based on a Lyapunov argument, which is simple but yields a relaxed result over those previously reported in the literature. Then, it is shown that the disc margin can be enlarged arbitrarily when the system is asymptotically null controllable with bounded controls and when a low-gain feedback is employed. Based on this fact, the discrete-time consensus problem is solved by a DLQR-based consensus controller. Simulation study shows that the DLQR-based consensus controller has better robustness property against model uncertainties in the input channel.},

keywords = {Consensus},

pubstate = {published},

tppubtype = {article}

}

@article{SeoShimBack10,

title = {Reduced-order Consensus Controllers for Output-coupled SISO Linear Systems},

author = {Jin Heon Seo and Hyungbo Shim and Juhoon Back},

doi = {10.1007/s12555-010-0623-8},

isbn = {1598-6446},

year  = {2010},

date = {2010-12-01},

journal = {International Journal of Control, Automation and Systems},

volume = {8},

number = {6},

pages = {1356-1363},

abstract = {In this paper, we continue the study of the consensus problem for multi-agent linear dynamic systems. All the agents have identical linear dynamics which can be of any order, and only the output information of each agents is delivered throughout the communication network. Under these settings, we show that the first-order and the second-order consensus problems can be solved by a first-order and a second-order dynamic filter, respectively. This holds even for high order dynamics, and therefore, the high order system does not have to use a high order consensus controller.},

keywords = {Consensus},

pubstate = {published},

tppubtype = {article}

}