• 한국건축시공학회지
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• 제22권2호
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• pp.161-169
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• 2022

정부[3]에서는 강관비계를 재래식 비계로 규정하고 일체형 작업발판인 시스템비계를 우선 설치하도록 제도화 하고 강관비계의 사용을 최대한 지양하고 있는 추세이다. 하지만 발전소, 플랜트 현장 등 장비의 진입이 안 되거나 본 구조물의 구조가 복잡한 곳, 그리고 지면에서 비계를 쌓아 올리지 못하는 곳에서는 강관비계를 설치하여 작업할 수 밖에 없다. 고소부위의 H-beam 구조물에 강관비계를 설치하여 작업자들이 안전하게 작업을 할 수 있도록 작업공간을 형성하기 위해서는 철골용 클램프의 성능은 매우 중요한 요소이다. 본 연구에서는 철골용 클램프의 설치 방향별 부재의 변형 및 인장하중에 대해 성능시험 및 구조해석 모델링을 통해 확인한 결과 설치 방향별 성능은 안전인증 기준인 인장하중 10,000N을 만족하는 것으로 확인 되었다. 다만 성능값은 만족하지만 부착부 누름 볼트의 변형발생이 확인되었고, 부착부 본체는 변형이 미미한 것으로 확인되었으므로 철골용 클램프는 하중이 전달되는 방향으로 설치하여 부착부 본체에 하중이 제대로 전달될 수 있도록 하는 것이 보다 안전한 방법이다.

• Journal of Chest Surgery
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• 제13권3호
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• pp.186-197
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• 1980

We attempted to evaluate the effectiveness of cold blood potassium cardioplegia [Group B] compared with that of intermittent aortic cross clamp with topical hypothermia [Group A] in each six dogs. The studies were performed under the extracorporeal circulation with moderate hypothermia by using Mongrel dogs. 1. In Group A [6], it was difficult to maintain the temperature below 20?. but in Group B [6], it was possible to maintain the temperature. 2. In blood pressure and myocardial recovery ability, Group B was more excellent than Group A. 3. There was no significant difference in Na+, Ca++ and Cl- between both groups, but in K+ level, Group A was mild decreased and Group B was nearly normal level. 4. In serum LDH level, Group A was higher than Group B, but in SGOT level there was no significance between both groups. 5. On electromicroscopical study, Group A showed severe change in mitochondria, but Group B was nearly normal view. Thus we suggest that cold blood potassium cardioplegia would be more effective than intermittent aortic cross clamp with topical hypothermia for myocardial protection in open heart surgery.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1444-1452
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• 2011

At present, Kyungbu high-speed railway is operated with 300km/h, Honam high-speed railway is being constructed with 350km/h, and the development for the overhead contact line system is to be conducted for the next-generation high-speed railway with the speed of 400km/h. It is necessary to set up the specification and criteria for the key parts such as dropper, termination clamp and tension insulator for the 400km/h railway line. In this paper, the specification and the criteria for dropper, termination clamp and tension insulator has been reviewed and proposed in order to secure long-term reliability and stability under the maximum speed of 400km/h. Also, the specification, criteria and international standards for 300km/h class and 350km/h class railway line system and the international standards related with the insulators have been reviewed, compared and analysed.

• 대한전기학회논문지:전력기술부문A
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• 제54권3호
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• pp.133-138
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• 2005

This paper presents a characteristics of horizontal swing angle in V type suspension string sets for 765kV T/L. The design of V type suspension string set does not differ from that of general string set for general towers, but it prevents instabilities from swing motion by the horizontal angle and by the wind pressure. We were designed specially 6 conductor yoke, arcing horn and earth horn. And we were decided to 550mm for a distance of strings. We were carried out characteristics of horizontal swing test and movement of mass center test for V-string sets of 400kN single, 300kN double and 400kN double. This products will be used for 765kV T/L of 1 circuit in suspension towers.

• Journal of Power Electronics
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• 제15권5호
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• pp.1200-1206
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• 2015

This paper proposes an actively clamped two-switch flyback converter. Compared to the conventional two-switch flyback converter, the proposed two-switch flyback converter operates with a wide duty cycle range. By using an active-clamp circuit, the proposed converter achieves zero-voltage switching for all of the power switches. Zero-current switching of an output diode is also achieved. Thus, compared with the conventional converter, the proposed converter realizes a higher efficiency with an extended duty cycle. The performance of the proposed converter is verified by the experimental results with use of a 1.0 kW prototype circuit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.227-231
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• 2003

In This paper, A novel zero-voltage-switching(ZVS) resonant DC-DC converter is proposed. it is composed of two symmetrical active-clamped circuits, The converter can achieve each switchs ZVS. proposed circuit is active clamp capacitor Ratios can be reduce switching voltage stress of each main switch. Simulation results using Pspice ver 9.2 show that the prove the validity of theoretical analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.247-250
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• 1997

A novel zero-voltage-switching(ZVS) isolated PWM converter for single stage power factor correction (PFC) is presented to improve the performance of the previously presented ZVT converter[5]. A simple clamp circuit in the primary side provides zero-voltage-switching condition to all semiconductor devices. This ZVS is achieved with minimum device voltage and current stresses. Operation principle, control strategy and features of the proposed converter are presented and verified by the experimental results from a 1.5 ㎾, 100 KHz laboratory prototype

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.136-139
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• 2001

The voltage resonating inverter has a defect in the switching element that works at 5 or 6 times higher than input voltage. Especially, it is very difficult to choose very high switching device for the 220[V]commercial voltage. In this paper, it is proposed the optimum method to realize the turbo 2000[W] power for induction cooker that is employed the 900[V] IGBT with decreasing operating voltage of the switching component by making the 220[V], 1500[W] inverter through the clamp mode voltage resonating inverter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.222-226
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• 2001

This paper compares three kinds of soft-switching circuits from viewpoints of surge suppression, load characteristic, and power efficiency for a tapped-inductor buck converter with low voltage and high current. As a result, these soft-switching techniques have achieved much higher efficiency of $80\%$ when compared with a hard-switching buck converter for the output condition of 1V and 20A.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.49-53
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• 2003

In this paper, to analyze efficiency characteristic, one of important factors in design of DC-DC converter prototype, theoretically derived power loss of individual components generating in DC-DC converter and compared theoretical results with experimental results. For evaluation of results, active clamp type Forward DC-DC converter with synchronous rectifier was composed of experimental converter. Efficiency result measured in experimental converter was compared with theoretical efficiency result derived in this paper. In comparative results, a fact that derived theoretical value and experimental value comparatively correspond have been able to verify.