• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.494-498
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• 1996

Three fuzzy input space partitoining methods, which are grid, tree, and scatter method, are mainly used until now. These partition methods represent good performance in the modeling of the linear system and nonlinear system with independent modeling variables. But in the case of the nonlinear system with the coupled modeling variables, there should be many fuzzy rules for acquiring the exact fuzzy model. In this paper, it shows that the fuzzy model is acquired using transformed modeling vector by linear transformation of the modeling vector.

• 전자공학회논문지A
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• 제30A권5호
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• pp.36-44
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• 1993

In this paper, a simple design method is represented for a contiguous-band waveguide manifold diplexer which employs a half-wavelength line at the input port of the singly terminated bandpass filterand has resonant-slot coupled E-plane T-junctions. This design method is based on the fact that the input impedance characteristics of the singly terminated bandpass filter are approximately unchanged when a resonant slot and a half-wavelength line at the input port of the filter are employed. This design method is also applicable to the design of the multiplexer. A contiguous-band waveguide manifold diplexer using the post coupled cavity filters is designed, constructed, and tested. The computed and experimental results show the validity of the theory.

• 전력전자학회논문지
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• 제27권2호
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• pp.85-91
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• 2022

This study proposes a high efficiency bridgeless Power Factor Correction (PFC) converter with improved common mode noise characteristics. Conventional PFC has limitations due to low efficiency and enlarged heat sink from considerable conduction loss of bridge diode. By applying a Common Mode (CM) coupled inductor, the proposed bridgeless PFC converter generates less conduction loss as only a small magnetizing current of the CM coupled inductor flows through the input diode, thereby reducing or removing heat sink. The input diode is alternately conducted every half cycle of 60 Hz AC input voltage while a negative node of AC input voltage is always connected to the ground, thus improving common mode noise characteristics. With the aim to improve switching loss and reverse recovery of output diode, the proposed circuit employs Critical Conduction Mode (CrM) operation and it features a simple Zero Current Detection (ZCD) circuit for the CrM. In addition, the input current sensing is possible with the shunt resistor instead of the expensive current sensor. Experimental results through 480 W prototype are presented to verify the validity of the proposed circuit.

• The Journal of the Acoustical Society of Korea
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• 제17권1E호
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• pp.14-19
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• 1998

This article describes the application of a coupled finite element-boundary element method to obtain the steady-state response of a sonar transducer. The sonar shell is simulated to be driven by electrical charges applied onto inner and outer surfaces of the shell. It is shown that at relatively low input frequency a beam pattern which is almost close to omnidirection can be obtained. The coupled FE-BE method is described in detail.

• 한국정보통신학회논문지
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• 제2권1호
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• pp.37-43
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• 1998

This article describes the application of a coupled finite element-boundary element method to obtain the steady-state response of a sonar transducer. The particular structure considered is a flooded piezoelectric spherical shell. The sonar shell is simulated to be driven by electrical charges applied onto inner and outer surfaces of the shell. It is shown that at relatively low input frequency a beam pattern which is almost close to omnidirection can be obtained. The coupled FE-BE method is described in detail.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.465-468
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• 1988

A n-well CMOS Operational Transconductance Amplifier -C(OTA-C) integrator with a wide linear input range is designed. The circuit designed has superior linearity of input voltage range compared with the conventional source-coupled pair OTA. The OTA developed in this paper is versatile in application: diverse applications are in the fields of linear amplifiers, continuous-time filters, gain control circuits, and analog multipliers, etc..

• 한국전자파학회논문지
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• 제15권11호
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• pp.1100-1107
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• 2004

본 논문에서는 다단 결합선로 여파기(edge coupled-line filter)의 입출력단을 탭 선로(tapped-line)의 형태로 구현하기 위하여 등가회로 기반의 새로운 설계법을 개발하여 적용하였다. 다단 결합선로 여파기는 입출력단의 선로 간격이 매우 좁아서(수 mil) 제작하기가 힘든 결함이 있는데, 이를 탭 선로로 대체함으로써 제작 시 오차에 덜 민감하고 밀링머신으로 쉽게 제작할 수 있도록 하였다. 또한, 본 논문에서 제안된 간단한 설계법을 사용하면 20 GHz 이하의 주파수 대역에서 20 % 이하의 대역폭 특성을 갖는 탭 선로의 파라미터를 얻을 수 있으며, 이를 바탕으로 정확한 탭 선로 여파기를 설계할 수 있다.

• Journal of Power Electronics
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• 제15권2호
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• pp.327-337
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• 2015

This study discusses the design of a parallel-operated DC-DC single-ended primary-inductor converter (SEPIC) for low-voltage application and current sharing with a constant output voltage. A coupled inductor is used for parallel-connected SEPIC topology. Generally, two separate inductors require different ripple currents, but a coupled inductor has the advantage of using the same ripple current. Furthermore, tightly coupled inductors require only half of the ripple current that separate inductors use. In this proposed work, tightly coupled inductors are used. These produce an output that is more efficient than that from separate inductors. Two SEPICs are also connected in parallel using the coupled inductors with a single common controller. An analog control circuit is designed to generate pulse width modulation (PWM) signals and to fulfill the closed-loop control function. A stable output current-sharing strategy is proposed in this system. An experimental setup is developed for a 18.5 V, 60 W parallel SEPIC (PSEPIC) converter, and the results are verified. Results indicate that the PSEPIC provides good response for the variation of input voltage and sudden change in load.

• 한국전자파학회논문지
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• 제19권2호
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• pp.114-120
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• 2008

본 논문에서는 일반적인 반 파장 평행 결합 선로 대역 통과 필터의 입 출력 결합 선로를 K-인버터로 변환하고, K-인버터를 $\pi$-형 전송선 등가로 대체함으로써 $\pi$-형 전송선 급전 구조를 갖는 구조의 대역 통과 필터를 제안하였다. 이 방법은 반 파장 결합 선로 대역 통과 필터의 입 출력 결합 선로 구현 문제에 대한 해결 방안을 제시한다. 또한, 기존의 탭 선로(tapped line) 구조의 설계 방법에 비해 설계 식이 매우 간단하고 정확하여, 특성의 적정화를 위한 노력과 시간을 상당히 줄일 수 있다. 제안된 이론을 바탕으로 $\pi$-형 전송선 급전 구조를 갖는 구조의 대역 통과 필터를 설계 및 제작하였고, 그 결과로부터 제안 방법의 타당성을 입증하였다.

• 대한조선학회논문집
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• 제43권5호
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• pp.597-603
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• 2006

The estimations of distributed and joint-excited input power for Power Flow Analysis are accomplished in this paper. Using Fourier transform, the displacements of infinite structures are derived, and the input power of distributed excitation can be estimated. The obtained results compare the real input power with the estimation of input power. When the exciting force acts on the joint of coupled structures, it is estimating the power that is transferred to each structure. Appling this input power, the results of energy density and intensity of Power Flow Analysis can be compared with the classical solutions.