• International Journal of Control, Automation, and Systems
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• v.3 no.spc2
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• pp.308-314
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• 2005

Transient stabilization with voltage regulation is investigated for a synchronous generator when the mechanical power is perturbed to any unknown value within its physical bounds so that the operating point of the system shifts to an unknown point. An adaptive excitation controller is designed based on the backstepping method with tuning functions. It will be shown that the adaptive control law proposed can achieve the convergence of the system states to the new equilibrium point in correspondence with the real value of the unknown mechanical power and the regulation of the terminal voltage to the required value. Simulation results are given to demonstrate the effectiveness of the proposed controller for the transient stabilization and voltage regulation.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.55-63
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• 1998

The symptoms that have same pathologic pattern written in the chapter of Soyangin's general pathology of the book 'Dongyi Soose Bowon' can give us a key to the Dr.Lee Je-Ma's point of view about the constitutional pathophysiology. As the result, Dr. Lee called the person who has yang-hyperactivity/yin-hypoactivity as So-Yang-In. And the Soyangin has two basic pathologic pathway ; excess of Yang-hyperactivity/excess of Yin-hypoactivity. Each pathologic pathway has variatons though, the pathologic pattern results in above two type. Excess Yin-hypoactivity has three variations of pathologic pattern. 1. smaller excess of Yin-hypoactivity with the normal range of Yang-hyperactivity 2. larger excess Yin-hypoactivity with the excitation of Yang-hyperactivity by the extrinsic factor 3. smaller excess Yin-hypoactivity with the loss of Yang-hyperactivity. And excess Yang-hyperactivity also has three variations. In my point of view, CVA, Hematemesis, Vommiting, Abdominal Pain, Gastric Dyscomfort has No.3 type and Asthmatic condition, Dysentery, Edema has No.1 type.

• Journal of Power Electronics
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• v.14 no.4
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• pp.796-805
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• 2014

A digital controller with a low-power approach for point-of-load synchronous buck converters is discussed and compared with its analog counterpart to confirm its feasibility for system integration. The tri-mode digital controller IC in $0.35{\mu}m$ CMOS process is presented to demonstrate solutions that include a PID, quarter PID, and robust RST compensators. These compensators address the steady-state, stand-by, and transient modes according to the system operating point. An idle-tone free condition for ${\Sigma}-{\Delta}$ DPWM reduces the inherent tone noise under DC-excitation. Compared with that of the traditional approach, this condition generates a quasi-pure modulation signal. Experimental results verify the closed-loop performances and confirm the power-saving mechanism of the proposed controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.516-523
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• 1998

Radiation efficiency of a cylindrical shell whose surface vibrates under harmonic distribution is investigated by theoretical solutions and Boundary Element Method. The vibration modes of a cylindrical shell is determined from experiment and is compared with the result of Finite Element Method. Harmonic vibration response of the cylindrical shell under the point excitation and the radiation phenomena from its response is analyzed by Finite Element Method and Boundary Element Method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.413-418
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• 2001

The moire phenomena, which are induced by mask vibration due to the excitation of speakers, degrades the color purity of CRT. So it is important to eliminate this phenomena to obtain a good CRT design. In this study we analyze the mask vibration by experiment as well as finite element method. To obtain the finite element solutions efficiently, an equivalent model was employed. The experimental and analysis results show reasonable agreements. An enhanced design configuration of mask welding points are suggested through this study.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.85-90
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• 1996

In the word, there is varied types of vibration, and these affect the mechanical industry. In this paper is plates with two parallel sides fixed. Electronic speckle pattern interferometry (ESPI) is one of the optical nondestructive testing technique. By using the ESPI, vibration modes for excitation point, a/b(ratio of longuitudinal and lateral length), and kind of specimen are measured and compared qualitatively with theoritical analysis that Warburton proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1055-1060
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• 2001

Springing phenomena of ships is introduced with its concept, research history and approach methodology. Being a hydroelasticity problem, non-linear vibration and stochastic process, springing was formulated and modeled in vibration point of view separating hydrodynamic force into system properties and excitation force. Both RAO and response spectrum as well as wave spectrum were presented as a case study of springing analysis for a flexible vessel with wide breadth. The effect of advance speed, heading angle and loading condition were investigated as parametric study. The results and observations showed availability of analysis for the prediction of the ship springing behavior.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1864-1871
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• 2012

This paper proposes the hybrid proportional integral(HBPI) controller for maximum power point tracking(MPPT) control of photovoltaic system. The output characteristics of the solar cell are a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. The MPPT control is a very important technique in order to increase an output and efficiency of the photovoltaic system. The conventional constant voltage(CV), perturbation and observation(PO) and incremental conductance(IC) are the method which finding maximum power point(MPP) by the continued self-excitation vibration, and uses the fixed step size. If the fixed step size is a large, the tracking speed of maximum power point is faster, but the tracking accuracy in the steady state is decreased. On the contrary, when the fixed step size is a small, the tracking accuracy is increased and the tracking speed is slower. Therefore, in order to solve these problems, this paper proposes HBPI controller that is adjusted gain of conventional PI control using fuzzy control, and the maximum power point tracks using this controller. The validity of the controller proposed in this paper proves through the results of the comparisons.

• The Journal of the Acoustical Society of Korea
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• v.14 no.4
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• pp.38-45
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• 1995

In this paper a way to improve the performance of the long term prediction is proposed, which adopts the Multi-band Excitation (MBE) method in addition to the Code-Excited Linear Prediction (CELP) method at low bit rates below 4.8 kbps. In the proposed method, the multiband long term prediction is performed on the periodic components which still remain after the long term prediction of the conventional CELP method. At this point, the whole frequency region is divided into subbands whose size is equal to the spacing between the harmonics of the fundamental frequency, and the periodic multiband excitation signals. are represented as the sum of sine waves approximately as large as the spectrum of the excitation signals, so that the actual characteristics of the excitation signals can be better taken into account. To evaluate the performance of the proposed method, computer simulation is performed at 4.8 kbps. The 4.8 kbps DoD CELP and the 4.4 kbps IMBE were chosen as the reference vocoders for the speech quality measure. The result of the perceptual speech quality measure showed that the performance of the proposed method is better than that of the 4.8 kbps DoD CELP vocoder, and similar to that of the 4.4 kbps IMBE vocoder.

• The Journal of the Acoustical Society of Korea
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• v.14 no.3
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• pp.5-13
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• 1995

This paper shows newly developed equations of cylindrical shell motion, which solutions are obtained as a set of linear equation. Each linear equation is derived along each axis of cylindrical coordinates. The admittance and the free wavenumber are obtained under assumption of point excition on a cylindrical shell. Their results are shown in figures. In this results, this paper shows a possibility that a vibration and a noise generated in a cylindrical shell can be formulated as a mathematical model.