• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.988-990
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• 1999

Using neural network approach, the diagnosis of faults in industrial process that requires observing multiple data simultaneously are studied in this paper. Two-stage diagnosis is proposed as the basic structure. The first stage detects the dynamic trend of each measurements and the second stage diagnosis the faults. This paper makes up for the disadvantage of neural about unknown faults. The potential of this approach is demonstrated in simulation using a model of tank reactor.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.39.3-39
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• 2002

In this paper, presented is a feedback control loop, for an in-plane gimbaled micro gyroscope based on methodology and state weighted model reduction technique. The micro gyroscope is the basic inertial sensors. To improve the performances such as stability, wide dynamic range, bandwidth and especially robustness, it is necessary to design a feedback control loop, which must be robust, because the manufacturing process errors can be large. Especially, to obtain wide bandwidth, the feedback controller is indispensable, because the gyroscope is high Q factor system and has small open loop bandwidth. Moreover, the feedback controller reduces the effect...

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.91.3-91
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• 2002

This paper describes a design of an induction motor control system for industrial sewing machines. On the basis of vector control principle, the control system is simulated by using the ACSL, implemented on a DSP(TMS320C31).A space vector modulation is used as the inverter switching strategy. For the application of industrial sewing machines, A fast acceleration (deceleration) and removal of velocity ripples are required, because a sewing quality and sewing machines life time depends on these characteristics. The designed control system has fast dynamic characteristics and small speed vibration. The result is applied to the industrial sewing machine and result are shown.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1179-1181
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• 1996

In this paper, method for direct adaptive control of discrete nonlinear systems using neural network is presented. Also, the stability problems are investigated in sense of the Lyapunov stability conditions. Through extensive simulation, the SOON is shown to be effective for indirect adaptive control of nonlinear dynamic systems.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1182-1185
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• 1996

The objective of this paper is to control a nonlinear dynamical systems based on Self-Organized Distributed Networks (SODN). The learning with the SODN is fast and precise. Such properties are caused from the local learning mechanism Each local network learns only data in a subregion. Methods for indirect adaptive control of nonlinear systems using the SODN is presented. Through extensive simulation, the SODN is shown to be effective for adaptive control of nonlinear dynamic systems.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.366-369
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• 1994

In this paper, reduced-order $H_{\infty}$ robust controller is designed for the drum-type boiler system. From the known nonlinear dynamic model, a linearized multivariable model is obtained. To reduce order of robust controller, observer-based proper $H_{\infty}$ compensator is designed. The designed controller has robust property against the influence of sensor noise, system parameter variation and model uncertainty. A good Performance of the designed controller is shown by simulation.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.153-160
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• 2003

Recently, deployments of firewalls and NATs ire increasing to provide network security features or to solve the problem of public IP shortage. But, in these environments, peers in different firewall or NAT environments may get limited services because they cannot open direct communicate channels. This can be a significant problem in pure P2P environments where the peers should get or provide services by opening direct channels among themselves. In this paper, we propose a scheme for dynamically selecting a peer that fan be used as a proxy server. The proxy server supports the communication between the peers in different firewall or NAT environments. The proposed scheme is operating system independent and supports bidirectional communication among the peers in P2P environments. Additionally, the proposed scheme can distribute network traffic by dynamically allocating proxy servers to the peers that is not located in the firewall or NAT environments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.115-120
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• 2011

The dynamic responses of a 5 MW wind turbine lifted by a floating crane with two elastic booms are analyzed. Dynamic equations of motions of a multibody system that consists of a floating crane, two elastic booms, and a wind turbine are derived. The six-degree-of-freedom (DOF) motions for the floating crane and the wind turbine are considered in the equations of motions. The hydrostatic force, the hydrodynamic force due to a regular wave, the mooring force, the wire rope force, and the gravitational force are considered as external forces. By solving the equations numerically, the dynamic responses of cargo are simulated. The simulation results are compared with those in the case of one elastic boom. Finally, the dynamic responses of the wind turbine lifted by the floating crane are analyzed under regular wave condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.4
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• pp.501-509
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• 2010

A floating crane is a crane-mounted ship and is used to assemble or to transport heavy blocks in shipyards. In this paper, the static and dynamic response of a floating crane and a heavy block that are connected using elastic booms and wire ropes are described. The static and dynamic equations of surge, pitch, and heave for the system are derived on the basis of flexible multibody system dynamics. The equations of motion are fully coupled and highly nonlinear since they involve nonlinear mass matrices, elastic stiffness matrices, quadratic velocity vectors, and generalized external forces. A floating frame of reference and nodal coordinates are employed to model the boom as a flexible body. The nonlinear hydrostatic force, linear hydrodynamic force, wire-rope force, and mooring force are considered as the external forces. For numerical analysis, the Hilber-Hughes-Taylor method for implicit integration is used. The dynamic responses of the cargo are analyzed with respect to the results obtained by static and numerical analyses.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.9
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• pp.791-799
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• 2016

To ensure the reliability and safety of various mechanical systems in accordance with their high-speed usage, it is necessary to evaluate the dynamic deformation behavior of structural materials under impact load. However, it is not easy to understand the dynamic deformation behavior of the structural materials using experimental methods in the high strain-rate range exceeding $10^4\;s^{-1}$. In this study, the Taylor bar impact test was conducted to investigate the dynamic deformation behavior of metallic materials in the high strain-rate region, using a high-speed photography system. Numerical analysis of the Taylor bar impact test was performed using AUTODYN S/W. The results of the analysis were compared with the experimental results, and the material behavior in the high strain-rate region was discussed.