• 한국정보통신학회논문지
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• 제13권10호
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• pp.2039-2044
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• 2009

본 논문에서는 다층형 결합 선로를 이용한 PSK 반송파 신호 복원 회로를 해석하고 설계 제작한다. 다층형 결합 선로 구조의 coupled line으로 구성되는 반송파 복원 6단자 소자는 다층형 구조를 가지며, 수신 전처리부의 6 단자 위상 상관기 구조와 동일한 구조를 갖는 일원화된 수신 구조 구현이 가능하다. 아울러 다층 결합 선로 6 단자 위상 상관기를 이용한 RML 기반 다중 모드 동기 복조형 반송파 신호 복원이 가능한 다층형 결합 선로 반송파 복원 회로 구조를 제안한다. 설계 제작된 다층형 결합 선로 구조 반송파 복원회로에 의한 직교 위상편이 방식 신호의 반송파 신호는 일정한 위상값과 반사 소자에 의해 발생되는 ${\pm}3o$ 이내인 위상차를 갖는 양호한 PSK 반송파 신호 특성을 나타내었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.145-145
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• 2011

Recently, multi-hole electrode RF capacitively coupled plasma discharge is being used in the deposition of microcrystalline silicon for thin film solar cell to increase the speed of deposition. To make efficient multi-hole electrode RF capacitively coupled plasma discharge, the hole diameter is to be designed concerning the plasma parameters. In past studies, the relationship between plasma parameters such as pressures and gas species, and hole diameter for efficient plasma density enhancement is experimentally shown. In the presentation, the relationship between plasma deriving frequency and hole diameter for efficient multi-hole electrode RF capacitively coupled plasma discharge is shown. In usual capacitively coupled plasma discharge, plasma parameter, such as plasma density, plasma impedence and plasma temperature, change as frequency increases. Because of the change, the optimum hole diameter of the multi-hole electrode RF capacitively coupled plasma for high density plasma is thought to be modified when the plasma deriving frequency changes. To see the frequency effect on the multi-hole RF capacitively coupled plasma is discharged and one of its electrode is changed from a plane electrode to a variety of multi-hole electrodes with different hole diameters. The discharge is derived by RF power source with various frequency and the plasma parameter is measured with RF compensated single Langmuir probe. The shrinkage of the hole diameter for efficient discharge is observed as the plasma deriving frequency increases.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.70-81
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• 2017

Various components of an engine nozzle are modeled as flexible multi-body components that are operated under high temperature and pressure. In this paper, in order to predict complex behavior of an engine nozzle, thermo-fluid-flexible multi-body dynamics coupled analysis framework was developed. Temperature and pressure on the nozzle wall were obtained by the steady-state flow analysis for a two-dimensional nozzle. The pressure and temperature-dependent material properties were delivered to the flexible multi-body dynamics analysis. Then the deflection and strain distribution for a nozzle configuration was obtained. Heat conduction and thermal analyses were done using MSC.NASTRAN. The present framework was validated for a simple nozzle configuration by using a one-way coupled analysis. A two-way coupled analysis was also performed for the simple nozzle with an arbitrary joint clearance, and an asymmetric flow was observed. Finally, the total strain result for a realistic nozzle configuration was obtained using the one-way and two-way coupled analyses.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권8호
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• pp.361-366
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• 2001

This thesis proposes a fuzzy logic cross coupled controller for a multi axis servo system. The overall control system consists of three elements: the axial position controller, the speed controller, and a fuzzy logic cross coupled controller. In conventional multi axis servo system, the motion of each axis is controlled independently without regard to the motion of other axes, in which the contour error, defined as the shortest distance between the desired and actual contours is compensated only by the position error of each axis. This decoupled control approach may result in degraded contouring performance due to such factors as mismatch of axial dynamics and axial loop gains. In practice, such systems contain many uncertainties, Therefore, the multi axis servo system must receive and evaluate the motion of all axes for a better contouring accuracy. Cross coupled controller utilizes all axis position error information simultaneously to produce accurate contours. However the existing cross coupled controllers cannot overcome friction, backlash and parameter variation. Also, since it is difficult to obtain an accurate mathematical model of multi axis system, here we investigate a fuzzy logic cross coupled controller method. Some simulations and experimental results are presented to illustrate the performance of the proposed controller.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2267-2272
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• 2009

본 논문에서는 다층형 결합 선로를 이용한 6-단자 위상 상관기와 동일한 구조를 갖는 반송파 복원기 그리고 위상 변위기를 갖는 일원화된 6-단자 직접변환 수신 전처리부를 설계 제작한다. 전력 분배기와 하이브리드 결합기로 구성되는 6-단자 소자는 다층형 결합 선로 구조로 이루어지며, 수신부 위상 상관기와 반송파 복원기 그리고 위상 변위기의 기본 구조 요소로 작용한다. 다층형 결합 선로 구조로 구성되는 일원화된 수신 전처리부는 구성이 간단하고 집적화가 용이하다. 설계 제작된 다층형 결합 구조 6-단자 수신 전처리부는 일정한 반송파 신호를 재생하고, PSK 전송 신호를 복원한다.

• 전력전자학회논문지
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• 제19권6호
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• pp.481-487
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• 2014

This study proposes a two-phase non-inverting buck-boost converter that uses a coupled inductor. The multi-phase converter has many advantages over single-phase counterparts, such as reduced output current ripple and conduction loss in switching devices and passive elements. Although the output current ripple of the multi-phase converter is reduced significantly because of the interleaved effect, the inductor current ripple is not reduced in multi-phase converters. One of the solutions to this problem is to use a coupled inductor. A 4 kW prototype converter is built and tested to verify the performance of the proposed converter.

• 한국정밀공학회지
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• 제21권9호
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• pp.127-134
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• 2004

It is difficult to have the existing structural optimization using coupled field analysis from CFD to structure analysis when the structure is influenced of fluid. Therefore in an initial model of this study after doing parameter design from the background of shape using topology optimization. and it is making a approximation formula using by the CFD-structure coupled-field analysis and design of experiment. By using this result, we conducted multi-objective optimization. We could confirm efficiency of stochastic method applicable in the scene of structure reliability design to be needed multi-objective optimization. And we presented a way of design that could overcome the time and space restriction in structural design such as the butterfly valve with the less experiment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.877-882
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• 2005

The definition of multi-coupled operation is that coupled two trainsets is able to be operated one trainset identically. That is to say, the one driver, coupled two trainsets can operate the traction and braking system, control vehicle doors, phanto-graph, HVAC and passenger room lighting system etc, such as one trainset controlling. This study will provide high speed train design engineer with introducing multi-coupled operation system electrically and presentation automatic complex coupler mechanism, and then this paper will be applied to design next generation high speed train system such as Jun-la/Ho-nam line

• The Journal of the Acoustical Society of Korea
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• 제13권1E호
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• pp.5-10
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• 1994

삼층 기판위의 삼중 결합 마이크로스트립 서로의 해석을 위한 수치해석의 일반식이 얻어졌다. 유한차분식을 얻기 위한 방법과 특이점 처리를 위한 최적의 방법이 구해졌다. 홀수 모드와 짝수 모드의 캐패시턴스와 특성 임피이던스의 수치해석 결과를 보였으며 그 결과들은 이층의 두께와 삼층의 마치크로스트립 폭의 비에 따라 구해졌다. 수치해석으로 구한 짝수 모드 캐패시턴스는 다른 수치해석 결과와 비교되었다.

• Structural Engineering and Mechanics
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• 제31권3호
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• pp.367-369
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• 2009

The aim of this discussion is to expose incorrect formulations and terms in the aforementioned paper.