• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.251-255
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• 1997

The conventional high frequency phase-shifted full bridge dc/dc converter has a disadvantage that a circulating current flows through transformer and switching devices during the freewheeling interval. Due to this circulating current, RMS current stress, conduction losses of transformer and switching devices are increased. To alleviate this problem, this paper provides a circulating current free type high frequency soft switching phase-shifted full bridge (FB) dc/dc converter with energy recovery snubber (ERS) attached at the secondary side of transformer. The energy recovery snubber (ERS) adopted in this study is consisted of three fast recovery diode(Ds1, DS2, Ds3), two resonant capacitor (Cs1, Cs2)

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.89-92
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• 2000

In this paper, an effective procedure is presented for the local recovery of displacements and stresses in multilayered composite panels, which incorporate the local refinement using mesh superposition. The mesh superposition method is used to refine the global coarse mesh by superimposing refined mesh to the localized zone of interest without transition zones. The finite element model used is a solid element based on the Hellinger-Reissner variational principle. The a posteriori computation of the through-the-thickness distributions of displacements and stresses is achieved using a predictor-corrector procedure. The procedure utilizes the superconvergent stresses and nodal displacements of the finite element patch. The element patch is generated by locally superimposing a refined local mesh to the coarse global mesh.

• 음성과학
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• 제9권3호
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• pp.237-250
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• 2002

Linguistically, 'Focus' is the element which includes new or unpresupposed information. It is usually signalled by prosodic prominence called the 'pitch accent'. The purpose of this study is to observe the realization of the focal accent in VP-ellipsis, especially, to affect the meaning recovery of elided VP. Asher (1999) gave evidence that focal stress should be on the higher verb and the AUX in order to recover the elided VP to the lower one. In this paper, the systematic patterning of focal accent to decide the elided meaning in VP-ellipsis is to be observed. The realization of focal accent by English native speakers is set as the criteria for the meaning recovery of the elided VP and is compared to Koreans'. Moreover, the focal accents of Koreans are observed and compared with respect to their English proficiency levels.

• Journal of Advanced Marine Engineering and Technology
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• 제21권2호
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• pp.178-185
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• 1997

According to the wide - spread use of rectifier in electronic equipments, such problems as electronic components failures or equipment disorders have been occurred due to current harmonics. To overcome these problems, power factor correction circuits employing boost converter have been used. The high switching stress of boost converter can be reduced by snubber circuit. Recently, research activities in snubber circuits have been directed to energy recovery snubber for improving the efficiency of power converter. In this study, a new passive snubber circuit which can recover trapped snubber energy without added control is proposed for boost converter. The control of boost converter with proposed snubber is the same as the conventional one. In addition, the energy recovery circuit can be implemented with a few passive components. The circuit operation is confirmed through simulation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.847-852
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• 2001

A thorough understanding of the transient behavior during load following and start-up is essential in the design and operation of an heat recovery steam generator(HRSG). During this period of time, material that is exposed to high temperature and experiences a large temperature variation is subject to high thermal stress. APESS(Advanced Plant Engineering & Simulation System) is a dynamic simulation software for power plant which is under being developed by Doosan Heavy Industries & Construction Co., Ltd. This paper present the introduction of APESS and the result of simulation for an heat recovery steam generator.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.68-70
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• 2006

A new low-cost energy-recovery circuit (ERC) for a plasma display panel (PDP) is proposed. It has two auxiliary switches clamped on a half sustain voltage, and inductor currents are built up before the PDP is charged and -discharged. Therefore, it features a low cost, fully charged/discharged PDP, zero voltage switching (ZVS), low electromagnetic interference (EMI), low current stress, no severe voltage notch, and high energy-recovery capability.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.78-80
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• 2006

A new low-cost asymmetric current-fed energy-recovery circuit (ERC) for a plasma display panel (PDP) is proposed. LC resonant circuit biased by $V_s/2$ and composed of single switch is used as ERC on both sides of the PDP, slow discharging and fast charging times can be employed, and inductor currents are built up before the PDP is charged and discharged. Therefore, it features a low cost, fully charged/discharged PDP, zero voltage switching (ZVS), low electromagnetic interference (EMI), low current stress, no severe voltage notch, and high energy-recovery capability.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.399-401
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• 2005

A new high performance energy-recovery circuit (ERC) for a plasma display panel (PDP) is proposed. Two different ERCs are employed on both sides of the PDP, and slow falling and fast rising times are applied. It features a zero voltage switching (ZVS), low electromagnetic interference (EMI), low current stress, high efficiency, no severe voltage notch, reduced sustaining voltage, and high energy-recovery capability.

• BMB Reports
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• 제31권2호
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• pp.201-208
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• 1998

Amino acid analogs, like other inducers of stress response, induce the synthesis of stress proteins in mammalian cells. In this study, Drosophila Kc cells, in which translation is tightly controlled during stress response, was treated with proline analogs, L-azetidine-2-carboxylic acid (AzC) and 3,4-dehydro-L-proline (dh-P). Kc cells exposed to AzC or dh-P induced the synthesis of several proteins which had the same molecular weights as known heat shock proteins. However, in Kc cells, normal protein synthesis still continued in the presence of amino acids analogs unlike in heat-shocked cells. For the induction of stress response, the incorporation of dh-P into the protein was not essential, but the incorporation of AzC was. The stress protein synthesis was regulated mainly at the transcriptional level by AzC, whereas it was regulated by dh-P at the transcription level and possibly posttranscription level. During recovery, the stress protein synthesis stopped sooner in analog-treated cells than in heat-shocked cells even though the accumulated amount of Hsp70 was much less in proline analogstreated cells. It could be concluded that the proline analogs, AzC and dh-P, induced stress response through a different mechanism from heat shock.

• Current Research on Agriculture and Life Sciences
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• 제16권
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• pp.24-30
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• 1998

수분(水分) 스트레스에 의한 식물체(植物體)의 방어기구(防禦機構)와 관련(關聯)된 superoxide dismutase와 catalase의 활성도(活性度) 변화(變化)를 조사(調査)한 결과(結果)는 다음과 같다. 수분(水分) 스트레스(drought, flooding) 처리시(處理時) 큰올콩과 은하콩 모두 수분(水分) 함량(含量)과 가용성(可溶性) 단백질(蛋白質) 함량(含量)이 감소(減少)하여 말성숙(末成熟) 노화(老化)를 나타내었다. 가시적(可視的)인 피해(被害)는 drought 처리시(處理時)가 flooding 처리(處理)에 비(比)해 크게 나타났고 큰올콩이 은하콩에 비(比)해 크게 나타났다. superoxide dismutase의 활성(活性)은 drought처리시(處理時) 2일(日)째에 급격(急激)한 감소(減少)를 보이다가 회복(回復)되고 다시 감소(減少)하는 경향(傾向)을 보였으며 flooding처리시(處理時)는 처리기간(處理期間)에 따라 점차(漸次) 감소(減少)하였고 큰올콩의 감소정도(減少程度)가 더 크게 나타났다. catalase의 활성(活性)은 drought처리시(處理時)는 감소(減少)하는 경향(傾向)이었으나 flooding처리시(處理時) 2일(日)째에 급격(急激)한 감소(減少)를 나타낸 후 일정(一定)하게 유지(維持)되는 경향(傾向)을 보였다. 수분(水分)스트레스 처리후(處理後) 3일간(日間)의 회복기(回復期)를 주었을 때 두 효소(酵素)의 활성(活性)은 점차(漸次) 회복(回復)되었다.