• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.179-182
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• 2001

인체 활동에 따라 우리 몸에는 다양한 전기적 생체신호가 발생하며 특히 뇌의 활동에 따라 발생되는 뇌파(EEG)는 비침습적 방법으로 측정될 수 있는 장점 때문에 뇌기능 연구 및 임상 등에서 널리 사용되어지고 있다. 또한 임상에서는 주로 뇌 신경계 질환환자의 병인 규명 및 기전 연구를 위하여 뇌파가 사용되어지고 있다. 최근에는 컴퓨터 발달에 따라 카오스, 비선형 이론 등의 다양한 방법으로 복잡한 시계열 신호인 뇌파를 분석하는 기법들이 개발되어 뇌파의 특징점을 찾아 임상에 활용하거나 뇌기능 연구에 적용하려는 연구가 진행되고 있다. 본 논문에서는 잡화(artifact)가 섞여 있는 뇌파신호 및 artifact가 제거된 다음 재구성된 뇌파신호(reconstructed EEG signal), 그리고 독립성분으로 분리된 각각의 신호에 대하여 특징점을 찾기 위하여 비선형 및 선형 분석을 실시하여 유의한 차이점을 밝혔다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.125-133
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• 2006

This paper presents comparison results of Step Response Model of Dynamic Matrix Control(DMC) for a drum-type boiler-turbine system of a fossil power plant. Two possible kinds of step response models are investigated in designing the DMC, one is developed with the linearization of theoretical model and the other is developed with the process step-test data. Then, the control performances of each model-based DMC are simulated and evaluated. It is observed that the simulation results with the step-response model based on the test data show satisfactory results, while the linearized model is not suitable for the control of boiler-turbine system.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.53-60
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• 2018

In this paper, we described the unknown parameter identification using Dual Extended Kalman Filter for precise control of 2-link manipulator. 2-link manipulator has highly non-linear characteristic with changed parameter thought tasks. The parameter kinds of mass and inertia of system is important to handle with the manipulator robustly. To solve the control problem by estimating the state and unknown parameters of the system through the proposed method. In order to verify the performance of proposed method, we simulate the implementation using Matlab and compare with results of RLS algorithm. At the results, proposed method has a better performance than those of RLS and verify the estimation performance in the parameter estimation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.7
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• pp.40-50
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• 2005

In this paper, preliminary results for performance prediction of a dual-rotor wind turbine generator system are presented. Blade element and momentum theories are used to model the aerodynamic forces and moments acting on the rotor blades, and multi-body dynamics approach is used to integrate the major components to represent the overall system. Not only the steady-state performance but the transient response characteristics are analyzed. Pitch control strategy to control the rotor speed and the generator output is proposed and its performance is verified through the nonlinear simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.609-610
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• 2011

최근 친환경 생활이 강조되는 오늘날, 자전거(bicycle) 이용자 수가 급격히 늘어나고 있다. 때문에 2륜 자전거의 무인화 및 다양한 기구학적 재해석과 구조학적 재해석을 시도하고 있으며 공학적으로 활발한 연구가 진행되고 있다. 본 논문은 복잡한 2륜 자전거의 복잡한 동역학 방정식을 분석한 결과 인버터 팬들럼 모델과 유사한 점을 수학적 전개를 통하여 알 수 있었다. 이렇게 근사화된 방정식 모델을 바탕으로 비선형 제어 알고리즘을 통하여 비선형 제어기를 설계하여 2륜 자전거의 주행 안정성에 대한 진행속도와 조향각(steering angle) 제어에 대한 상관관계에 대한 연구를 시뮬레이션을 통하여 결과를 분석하고자 한다. 이러한 분석을 통한 2륜 자전거의 자세제어를 통하여 기타 로봇의 자세제어 및 다양한 시스템에 적용 가능성을 제시하고자 한다.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.845-852
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• 1995

We investigate the concurrent solution of differential equations by the waveform relaxation (WR) method, an iterative method for analyzing linear and nonlinear dynamical systems in the time do-main. The method, at each iteration, decomposes the dynamical system into several subsystems, each of which is analyzed for the entire given time interval. The method, when efficiently implemented, results in algorithms with a highly parallelizable concurrent fraction. In this paper, the waveform relaxation method is introduced and applied to two types of reactor dynamics problems. It is concluded that the U method can be applied to reactor dynamics equations, but that its parallel performance on the KMRR dynamics is only modest.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.26-34
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• 2015

In this paper, a fuzzy compensated PID control system is proposed for formation control of mobile robots. The control system consists of a kinematic controller based on the leader-follower approach and a dynamic controller to handle dynamics effects of mobile robots. To maintain the desired formation of mobile robots, the dynamic controller is equipped with a PID controller; however, the PID controller has poor performance in nonlinear and changing environments. In order to improve these problem, we applied the additional fuzzy compensator. Finally, the proposed control system has been evaluated through computer simulation to demonstrate the improved results.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.217-218
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• 2007

최근 개발된 비선형 자동조종 제어기를 사용하면 비행 환경에 무관하게 BTT 미사일의 입출력 동특성이 일정한 선형 시스템의 형대로 표현될 수 있다. 본 논문에서는 이와 같은 특성을 바탕으로 BTT 미사일이 목표물의 취약 지점을 정밀하게 요격할 수 있도록 자동조종장치 동역학의 시간 지연 효과를 고려하여 표적 충돌각을 최소화하는 최적 종말 유도 법칙을 설계하였다. 제안된 최적 종말 유도 법칙은 극좌표 변환을 사용하지 않기 때문에 가제어성을 보장하며, 가속도 편향값을 사용하지 않기 때문에 기존의 유도 법칙에 비하여 미사일의 기동성을 향상시킬 수 있는 장점을 갖는다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.175-181
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• 2010

This paper presents the dynamic analysis method for estimating the performance of flat-type blades in wiper systems. The blade has nonlinear characteristics since the rubber is a hyper-elastic material. Thus, modal coordinate and absolute nodal coordinate formulations were used to describe the dynamic characteristic of the blade. The blade was structurally analyzed to find the bending characteristics of the cross section of the blade. According to the analysis results, the blade section is divided into three deformation bodies: rigid, small, and large. For the small deformation body, the modal coordinate formulation is used, while the absolute nodal coordinate formulation is used for the large deformation body. To verify the dynamic analysis result, an experiment was performed. The simulation and experiment results were compared to verify the flexible multi-body dynamic model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.46-55
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• 2002

A nonlinear aeroelastic analysis system in transonic and supersonic flows has been developed using high speed parallel processing technique on the network based PC-clustered machines. This paper includes the coupling of advanced numerical techniques such as computational structural dynamics (CSD), finite element method (FEM) and computational fluid dynamics (CFD). The unsteady Euler solver on dynamic unstructured meshes is employed and coupled with computational aeroelastic solvers. Thus it can give very accurate engineering data in the structural and aeroelastic design of flight vehicles. To show the great potential of useful application, transonic and supersonic flutter analyses have been conducted for a complete aircraft model under developing in Korea.