List of English Publication

@article{nokey,

title = {Evaluating MR-GPR and MR-NN: An Exploration of Data-driven Control Methods for Nonlinear Systems},

author = {Hyuntae Kim and Hamin Chang and Hyungbo Shim},

url = {https://rdcu.be/d04xd},

doi = {/10.1007/s12555-023-0695-x},

issn = {1598-6446},

year  = {2024},

date = {2024-08-01},

urldate = {2024-08-01},

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

volume = {22},

pages = {2934–2941},

abstract = {This paper addresses the challenge of data-driven control of nonlinear systems, focusing on the limi-tations and capabilities of model reference Gaussian process regression (MR-GPR) and its evolved counterpart,model reference neural networks (MR-NN). MR-GPR, based on Gaussian processes renowned for their adaptabil-ity to diverse data structures, encounters scalability issues especially when handling large datasets. To address theselimitations, this paper introduces MR-NN, an extension of MR-GPR, leveraging neural networks (NN) to managelarge datasets and capture complex nonlinear dynamics effectively. We present a comprehensive evaluation of bothmethods through a classical control problem of the inverted pendulum, a system well-recognized for its nonlinearbehavior. Numerical experiments are conducted to compare the methods in terms of control performance, compu-tational efficiency, and reliability.},

keywords = {Data-driven control, Gaussian process, Neural Network, nonlinear systems, Stability, System identification},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Path Generating Inverse Gaussian Process Regression for Data-Driven Ultimate Boundedness Control of Nonlinear Systems},

author = {Yeongjun Jang and Hamin Chang and Heein Park and Hyungbo Shim},

doi = {10.1109/LCSYS.2024.3403525},

issn = {2475-1456},

year  = {2024},

date = {2024-05-20},

urldate = {2024-05-20},

journal = {IEEE Control Systems Letters},

volume = {8},

pages = {748 - 753},

abstract = {A data-driven ultimate boundedness controller for a nonlinear system is proposed. The controller is designed based on the inverse model of the system identified by Gaussian process regression with state/input measurement data to track a reference trajectory suitable for achieving a desired ultimate bound. In particular, a suitable reference trajectory is actively generated based on the data that have been used for the identification. For this reason, the controller is named the path generating inverse Gaussian process regression (PGIGP) controller. We provide a sufficient condition on the data under which the PGIGP controller guarantees ultimate boundedness with a desired ultimate bound. It is shown that the condition can serve as a practical guideline for data acquisition and, conversely, be employed to determine the baseline of the control performance achievable from a given dataset. The effectiveness of the PGIGP controller is demonstrated through numerical simulations.},

keywords = {Data-driven control, Gaussian process, nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{MoosapourAtaeiShimEkramian19b,

title = {Asymptotic stabilization of a class of nonlinear systems with long input delay in the presence of disturbance},

author = {Seyed Hamze Moosapour and Mohammad Ataei and Hyungbo Shim and Mohsen Ekramian},

doi = {10.1016/j.isatra.2019.01.040},

issn = {0019-0578},

year  = {2019},

date = {2019-08-01},

urldate = {2019-08-01},

journal = {ISA Transactions},

volume = {91},

pages = {125-134},

abstract = {Asymptotic stabilization of a class of nonlinear systems with known constant long input delay is addressed in the presence of external disturbance by applying sliding mode control method. Modified prediction variable scheme is employed to compensate long delays in the input, where conventional prediction variable approaches cannot be employed. This is mainly due to the fact that the external disturbance appears in the prediction variable, which renders the controller dependent on the external disturbance. In order to tackle this problem, the nonlinear disturbance observer based predictor is used. A suitable disturbance observer is designed to estimate the external disturbance that appears in the prediction variable. Respected to some existing results, the prediction-based control for more general class of the nonlinear systems in the presence of external disturbance is the main contribution of this paper. Actuator and sensor delays exist in the most common dynamic systems. So, the proposed control scheme can be employed in many conventional systems. The simulation results indicate the robustness and efficiency of the proposed controller.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{ShimJi08,

title = {Determination of Stability with respect to Positive Orthant for a Class of Positive Nonlinear Systems},

author = {Hyungbo Shim and Nam Hoon Jo},

doi = {10.1109/TAC.2008.921018},

issn = {0018-9286},

year  = {2008},

date = {2008-06-01},

journal = {IEEE Transactions on Automatic Control},

volume = {53},

number = {5},

pages = {1329-1334},

abstract = {When dealing with positive nonlinear systems, conventional theory requires too much for the stability of equilibrium points located on the boundary of the positive orthant, which encourages the consideration of stability with respect to the positive orthant. Generalizing this concept to the stability of a family of equilibrium points with non-vanishing Basin of attraction (NvBA)-stability has been introduced, which often becomes of interest when positive systems undergo bifurcations. In this technical note, we present a simple condition that can be employed for determining the NvBA-stability with respect to the positive orthant. The proposed condition is applicable to a class of nonlinear systems of certain Jacobian structure and is tailormade for this system. An illustrative example is included in order to help the exposition of the technical note.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{SonYangShimSeo04,

title = {Feedback passivity approach to output feedback disturbance attenuation for uncertain nonlinear systems},

author = {Young Ik Son and Jongwook Yang and Nam Hoon Jo and Hyungbo Shim and Jin Heon Seo},

doi = {10.1080/00207720410001734246},

issn = {0020-7721},

year  = {2004},

date = {2004-03-16},

journal = {International Journal of Systems Science},

volume = {35},

number = {8},

pages = {467-477},

abstract = {The problem of output feedback disturbance attenuation for a class of uncertain nonlinear systems is studied based on output feedback passification. Previous work on output feedback disturbance attenuation is extended to the case where (1) the nominal system is not transformable into the normal form and (2) the uncertainty is parameterized nonlinearly. An adaptive output feedback controller is also provided that makes a nonlinear system passive. The paper then considers the output feedback disturbance attenuation problem for a class of uncertain nonlinear systems in the normal form and of relative degree one. The difference is that the result is applicable to nonlinear systems that include the uncertainty in the input matrix and do not satisfy the matching condition.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{SonShimJoSeo03b,

title = {Output feedback passification of nonlinear systems not in normal form},

author = {Young Ik Son and Hyungbo Shim and Nam Hoon Jo and Jin Heon Seo},

url = {https://www.researchgate.net/publication/294644438_Output_Feedback_Passification_of_Nonlinear_Systems_not_in_Normal_Form},

issn = {0916-8508},

year  = {2003},

date = {2003-05-01},

journal = {IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences},

volume = {E86A},

number = {5},

pages = {1312-1315},

abstract = {In this paper, the problem of output feedback passification for nonlinear systems is considered. Contrary to the conventional methodologies, our approach does not require the normal form representation of the system. Consequent advantages include that the system need not have a well-defined relative degree. In particular, we present a necessary and sufficient condition for output feedback passification without relying on the normal form. The proposed condition finally leads to an extension for a recent result when the system does have a normal form.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{ChoiShimSonSeo03,

title = {Design of an adaptive observer for a class of nonlinear systems},

author = {Y.U. Choi and Hyungbo Shim and Young Ik Son and Jin Heon Seo},

issn = {1598-6446},

year  = {2003},

date = {2003-01-01},

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

volume = {1},

number = {1},

pages = {28-34},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{JoSeo00,

title = {Input output linearization approach to state observer design for nonlinear system},

author = {Nam Hoon Jo and Jin Heon Seo},

url = {http://s-space.snu.ac.kr/handle/10371/37549},

doi = {10.1109/9.895580},

issn = {0018-9286},

year  = {2000},

date = {2000-12-01},

journal = {IEEE Transactions on Automatic Control},

volume = {45},

number = {12},

pages = {2388-2393},

abstract = {Presents a state observer for a class of nonlinear systems based on the input output linearization. While the previous result presented state observers for nonlinear systems of full relative degree, we proposed a procedure fur the design of nonlinear state observers which do not require the hypothesis of full relative degree. Assuming that there exists a global state observer for internal dynamics and that some functions are globally Lipschitz, we can design a globally convergent state observer. It is also shown that if the zero dynamics are locally exponentially stable, then there exists a local state observer. An example is given to illustrate the proposed design of nonlinear state observers.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{JoSeo00b,

title = {A state observer for nonlinear systems and its application to ball and beam system},

author = {Nam Hoon Jo and Jin Heon Seo},

doi = {10.1109/9.855562},

issn = {0018-9286},

year  = {2000},

date = {2000-05-01},

journal = {IEEE Transactions on Automatic Control},

volume = {45},

number = {5},

pages = {968-973},

abstract = {In this paper, we present a state observer for single-input/single-output nonlinear systems which fail to have well defined relative degree. It is shown that there exists a local state observer for a nonlinear system if it has robust relative degree n. The proposed observer utilizes the coordinate change which transforms a system into an approximate normal form. The proposed method is applied to a ball and beam system, and simulation results show that substantial improvement in the performance was achieved compared with other local observers.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{JoJooNohLeeSeo99,

title = {Robust stabilization of nonminimum phase nonlinear systems},

author = {Nam Hoon Jo and  Sung-Jun Joo and Dae Jong Noh and Sang-Hyuk Lee and Jin Heon Seo},

year  = {1999},

date = {1999-06-01},

journal = {Journal of Electrical Engineering and Information Science},

volume = {4},

number = {4},

pages = {305-314},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}

@article{ShimByunSeo99,

title = {Comments on "Observers for nonlinear systems in steady state},

author = {Hyungbo Shim and Jijoon Byun and Jin Heon Seo},

doi = {10.1109/9.751356},

issn = {0018-9286},

year  = {1999},

date = {1999-03-01},

journal = {IEEE Transactions on Automatic Control},

volume = {44},

number = {3},

pages = {587},

abstract = {In the above paper (Hunt and Verma, 1994), a nonlinear observer has been constructed when an initial error is sufficiently small. However, the proof of Lemma 2.2/sup /contains some errors. The authors provide a correct proof of Lemma 2.2 and show that the results still hold, but with reduced bounds of the initial error, states, and the new input.},

keywords = {nonlinear systems},

pubstate = {published},

tppubtype = {article}

}