• 전자공학회논문지
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• 제50권1호
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• pp.46-50
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• 2013

고조파를 제거하는 기능을 갖는 윌킨슨 전력분배기를 나타내었다. 종래의 윌킨슨 전력분배기에서 선로 변환기의 양단에 제거할 고조파의 수만큼의 전송선로를 추가한 후에 새로운 윌킨슨 전력분배기의 해를 구할 수 있다. 실험적인 결과는 기본 주파수에서는 종래의 기능을 유지하면서 2차 및 3차 고조파를 -45.3 dB, 및 -46.4 dB의 억압비를 나타내었다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.197-201
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• 2006

Folded lines are applied to design a compact microstrip ring hybrid. Using the proposed structure we achieve both significant size reduction and good harmonic suppression with the same results of conventional ring hybrid at 2.41GHz. Including the third harmonic frequency, up to 11GHz band harmonics are suppressed to -20dB. The size of the proposed ring-hybrid is reduced to one forth of the conventional ring hybrid. The measured frequency responses agree well with simulated ones.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.1-2
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• 2013

In this paper, we inject input currents having $3^{rd}$ harmonic to reduce the capacitance of DC link capacitors in single-phase converters. If the input current with third harmonic is injected, the required capacitance can be reduced by minimizing the difference between the input and output power. To control the input current, instead of PI control done in rotating frame, PR controller is used with the proposed separate current control method for fundamental and $3^{rd}$ harmonic components. The validity of the proposed method has been demonstrated by simulation results.

• 한국지능시스템학회논문지
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• 제20권3호
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• pp.434-440
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• 2010

In this paper, we define generalized induced linguistic aggregation operator called generalized induced linguistic ordered weighted harmonic mean(GILOWHM) operator. Each object processed by this operator consists of three components, where the first component represents the importance degree or character of the second component, and the second component isused to induce an ordering, through the first component, over the third components which are linguistic variables and then aggregated. It is shown that the induced linguistic ordered weighted harmonic mean(ILOWHM) operator and linguistic ordered weighted harmonic mean(LOWHM) operator are the special cases of the GILOWHM operator. Based on the GILOWHM and LWHM operators, we develop an approach to group decision making with linguistic preference relations. Finally, a numerical example is used to illustrate the applicability of the proposed approach.

• Journal of Magnetics
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• 제21권4호
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• pp.561-569
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• 2016

Although pretty methods have been proposed to reduce torque ripple, they generally suffer from the decreased torque density. This paper will investigate the spoke-type interior permanent magnet (IPM) machine with shaping methods, including the sinusoidal (SIN), the inverse cosine (ICS), the sinusoidal with third harmonic (SIN+3rd), and the inverse cosine with third harmonic (ICS+3rd). In order to obtain low torque ripple and high torque density, the shaping method applied in rotor and stator at the same time, termed as the dual-shaping method, is proposed. This method is analytically derived and further confirmed by finite element method (FEM). It turns out that the ICS and ICS+3rd shaping methods are more suitable for outer rotors, while the SIN and the SIN+3rd shaping method should be used in inner stators. The original machine, the singular shaped machines and the dual-shaped machines on electromagnetic performances are compared for evaluation. The results verify that the dual-shaping method can improve torque density, whilst reducing torque ripple.

• 전기전자학회논문지
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• 제23권2호
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• pp.495-501
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• 2019

본 논문에서는 정류 브리지 다이오드를 갖는 단상 무정전전원장치의 전원측 고조파 및 역률 개선을 위한 가변형 고조파 필터를 제안한다. 2레벨 이상의 전력변환방식을 적용한 무정전전원장치는 전원측 고조파 및 역률 특성이 우수한 반면, 전 브리지 방식의 무정전전원장치는 전원측에 제 3고조파, 제 5고조파, 제 7고조파 및 역률 저하를 심각하게 야기한다. 이에 따라 단상 전 브리지 동작에 의해 야기된 (2n+1)차 고조파 제거 및 역률 개선을 위한 가변형 고조파 필터를 제안하고자 한다. 제안한 가변형 고조파 필터의 성능을 평가하기 위해 다양한 시뮬레이션과 실험을 진행하여 타당성을 검증하였다.

• 한국임상수의학회지
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• 제39권1호
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• pp.1-8
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• 2022

The current, retrospective study aimed to assess the short-term prognosis and postoperative complications associated with the surgical correction of elongated soft palate using harmonic scalpel and to compare the postoperative complications associated with the application of harmonic scalpel and traditional surgery using Metzenbaum scissors. Harmonic scalpel was used to perform staphylectomy in 21 dogs. A total of ten dogs underwent sacculectomy; six dogs with harmonic scalpel and four dogs using Metzenbaum scissors. Stenotic nares were corrected by wedge resection. Postoperative complications were recorded through monitoring and radiographic examinations. Telephone interviews were conducted on the first, third, and seventh day after discharge and continued until the resolution of postoperative complications. Postoperative edema at the surgical site was identified and mitigated within a day or two. Snoring and dyspnea improved dramatically in the group that underwent staphylectomy alone. Moreover, three dogs presented with postoperative gastrointestinal complications, especially retching. The symptoms persisted for seven days and ten days in two dogs that underwent sacculectomy with harmonic scalpel and for two days in one dog that underwent sacculectomy with Metzenbaum scissors. The clinical signs and symptoms of brachycephalic syndrome disappeared without recurrence. Harmonic scalpel provides a hemostatic effect during staphylectomy, is convenient, and does not cause postoperative complications. Conversely, the use of harmonic scalpel during sacculectomy necessitated a longer period for the resolution of complications without any significant hemostatic efficacy, compared to traditional surgery.

• 대한전기학회논문지
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• 제38권5호
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• pp.362-369
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• 1989

A method to increase the output voltage of the PWM inverter within linear range is considered. A new modulation wave is used, which is made by injecting the third harmonic wave into the sinusoidal wave. The optimum region for improving the output voltage keeping the linear control characteristic is obtained by digital simulation. Furthermore, the distortion factor in the optimum region is less than that calculated when the maximum output voltage can be obtained in the sinusoidal PWM inverter.

• 호남수학학술지
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• 제43권4호
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• pp.701-715
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• 2021

In this paper, we study almost complex Norden Silver manifolds and Kaehler-Norden Silver manifolds. We define adapted connections of first, second and third type to an almost complex Norden Silver manifold and establish the necessary and sufficient conditions for the integrability of almost complex Norden Silver structure. Moreover, we investigate that a complex Norden Silver map is a harmonic map between Kaehler-Norden Silver manifolds.

• 한국통신학회논문지
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• 제30권11A호
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• pp.1104-1109
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• 2005

본 논문에서는 주파수 채배기 이론에 근거하여 단일 능동소자로 입력된 기본 LO 주파수($f_{LO}$)의 3차 고조파 성분($3f_{LO}$)의 진폭이 최대가 되는 바이어스 전압을 선택하여 두 입력신호($f_{RF}$, $f_{LO}$)에 대해서 고차 출력신호성분($f_{RF}{\pm}3f_{LO}$)이 최대가 되는 고조파 먹서(harmonic mixer)를 설계 및 제작하였다. 제안된 설계 방법에 의해서 제작된 고조파 먹서는 플라스틱(Plastic) 패키지의 MESFET 소자를 사용하여 기존 Ka-대역에서 동작하는 믹서 회로들이 나타내는 높은 부품 가격, 생산성 및 회로의 복잡도 문제를 해결할 수 있었으며 RF 주파수신호($f_{RF}$=33.5GHz)에 대해서 LO 주파수 신호($f_{LO}$=11.5 GHz)의 3차 고조파 신호($3f_{LO}$=34.5 GHz)가 최대가 되는 게이트 바이어스 전압을 선택하여 중간주파수($3f_{LO}-f_{RF}$=1.0GHz)에서 -10 dB의 낮은 변환 손실 특성을 나타내었다.