• ETRI Journal
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• 제35권4호
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• pp.603-609
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• 2013

In this paper, we present a 600-V reverse conducting insulated gate bipolar transistor (RC-IGBT) for soft and hard switching applications, such as general purpose inverters. The newly developed RC-IGBT uses the deep reactive-ion etching trench technology without the thin wafer process technology. Therefore, a freewheeling diode (FWD) is monolithically integrated in an IGBT chip. The proposed RC-IGBT operates as an IGBT in forward conducting mode and as an FWD in reverse conducting mode. Also, to avoid the destructive failure of the gate oxide under the surge current and abnormal conditions, a protective Zener diode is successfully integrated in the gate electrode without compromising the operation performance of the IGBT.

• 한국전기전자재료학회논문지
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• 제33권3호
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• pp.177-180
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• 2020

This paper focuses on the 1,200-V level reverse conducting-insulated gate bipolar transistor (RC-IGBT). The structure of the RC-IGBT has an n+ collector at the collector terminal. The breakdown voltage, V_th, V_ce-sat, and turn-off time, and the electrical characteristics of a field-stop IGBT (FS-IGBT) and RC-IGBT are compared and analyzed using simulations. Based on the results, the RC-IGBT obtained a turn-off time of 320.6 ㎲ and a breakdown voltage of 1,720 V, while the FS-IGBT obtained a turn-off time of 742.2 ㎲ and a breakdown voltage of 1,440 V. Therefore, RC-IGBTs have faster on/off transitions and a higher breakdown voltage, which can reduce the size of the element.

• 대한가정학회지
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• 제45권9호
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• pp.99-111
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• 2007

The purpose of this study was to find the effects of reverse mortgage including lands for rural elderly households. The data were drawn from 2005 Farm Household Economy Survey. And 1,165 households, which householder age were 65 to 75 and owned lands, were selected. The major findings as follows; First, in the case of conducting mortgage using only lands in rural area, the average substitute rate of current consumption was found to be over 100%(LTV=100%). This result implied that the conducting mortgage with land could be very effective for enhancing economic well-being of rural elderly households. Second, in the case of conducting mortgage using only shelters in rural area, the average substitute rate of current consumption was found to be only 25.7% (LTV=100%). This result implied that the conducting mortgage with only shelters could be no use for enhancing economic well-being of rural elderly households. Third, with FTA, it is time to rebuild agribusiness from small farm with family business to scale of farm business. It is expected the mortgage system with lands may very effective for not only enhancing economic well-being of rural elderly households, but for better farm business.

• Journal of Advanced Marine Engineering and Technology
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• 제29권7호
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• pp.785-794
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• 2005

Modern ship hulls of large oil carriers and container carrers have become more flexible with scantling optimization and increase in ship length. On the other hand. as the demand for power has increased with the ship size. shaft diameters have become larger and stiffer. Consequently. the alignment of the propulsion system has become more sensitive to hull girder deflections. resulting in difficulties in analyzing the alignment and conducting the alignment procedure. Accordingly. the frequency of shaft alignment related bearing damages has increased significantly in recent years. The alignment related damages are mostly attributed to inadequate analyses. changes in the design of the vessel. shipyards' practices in conducting the alignment. and a lack of well defined analytical criteria. The hull deflections should be considered at the design stage to minimize the bearing damage caused by hull deflection. Hull deflections can be estimated by analytical approach and reverse calculation using the measured data. The hull girder deflection analysis using the reverse calculation will be introduced in this paper.

• 멤브레인
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• 제27권5호
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• pp.434-440
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• 2017

본 연구에서는 역전기투석 공정에서 발생 가능한 막오염 현상을 in-situ로 측정하기 위하여 임피던스 스펙트로스코피 방법을 도입하여 실제 발생한 막오염 현상 측정 방법을 제시하였다. 얻어진 임피던스 데이터를 활용하여 Nyquist 도시법과 어드미턴스 도시법으로 스펙트럼을 도시하였으며 두 도시법 모두 유의미한 막오염 현상을 감지할 수 있었다. 또한 초기 막오염 현상에서 음이온 교환막 표면에 막오염물의 불안정한 축적 현상 및 역전기투석 공정의 운전 시간에 따른 막오염층의 구조적 변화를 감지할 수 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.36-38
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• 2001

A basic structure of 2500V-4500V reverse-conducting GCT (RC-GCT) is given in this paper. The punch-through type (PT) is adopted for narrow N-base with high resistivity so that the fast turn-off and low on-state voltage can be achieved. The photo mask design was made upon the both turn-off performance and solution of separation between GCT and integrated freewheeling diode (FWD) part. The turn-on and turn-off characteristics for reserve-conducting gate commutated thyristors (RC-GCTs) were investigated by ISE simulation. Additionally, the local carrier lifetime control by proton irradiation was adopted so as not only to obtain the reduction of turn-off losses of GCT but also to reach a soft reverse recovering characteristics of FWD

• 방송공학회논문지
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• 제26권7호
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• pp.862-867
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• 2021

Although Deep Neural Networks (DNNs) have shown remarkable performance in various artificial intelligence fields, it is well known that DNNs are vulnerable to adversarial attacks. Since adversarial attacks are implemented by adding perturbations onto benign examples, increasing the sparsity of DNNs minimizes the propagation of errors to high-level layers. In this paper, unlike the traditional pruning scheme removing low magnitude weights, we eliminate high magnitude weights that are usually considered high absolute values, named 'reverse pruning' to ensure robustness. By conducting both theoretical and experimental analyses, we observe that reverse pruning ensures the robustness of DNNs. Experimental results show that our reverse pruning outperforms previous work with 29.01% in Top-1 accuracy on perturbed CIFAR-10. However, reverse pruning does not guarantee benign samples. To relax this problem, we further conducted experiments by adding a regularization term for the high magnitude weights. With adding the regularization term, we also applied conventional pruning to ensure the robustness of DNNs.

• 한국건설관리학회논문집
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• 제15권3호
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• pp.3-11
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• 2014

최근 국내 건축경기 불황에 대한 방안으로 리모델링 시장이 신규 유망시장으로 주목받고 있다. 하지만 리모델링 공사를 추진하는데 있어, 도면의 부재나 도면 정보의 부족 등으로 시공에 상당한 어려움을 겪고 있다. 이러한 문제를 해결하기 위해 역설계 기술을 이용한 도면화 기술에 대한 활발한 연구가 진행 중이지만, 현장에서는 역설계 기술의 정확도와 도면화 시간에 대한 정보부족으로 역설계 기술의 사용을 주저하고 있다. 따라서 본 연구에서는 실험을 통해 역설계 과정 중 3차원 형상 정보를 획득하는데 있어서 포인트 데이터 정밀도에 따른 측정시간과 오차를 분석하여 최적의 포인트 데이터 획득 정밀도를 제안하고자 한다.

• 한국시뮬레이션학회논문지
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• 제29권3호
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• pp.27-40
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• 2020

시뮬레이션 모델을 통해 가상 전장에서 국방체계의 효과도를 분석하는 것을 순방향 시뮬레이션이라고 할 때, 높은 효과도를 가지는 국방체계를 설계하기 위해서는 역방향 시뮬레이션이 요구된다. 즉 효과도 분석 모델을 바탕으로 높은 효과도를 달성하기 위한 군사 장비들의 제원 및 성능, 그리고 운용 전술을 역으로 도출해야 한다. 하지만 역모델을 도출할 수 없는 시뮬레이션 모델의 특성상 역방향 시뮬레이션은 많은 순방향 시뮬레이션 반복을 요구하므로 효율성의 문제를 초래한다. 본 논문에서는 반복 횟수를 줄임으로 역방향 시뮬레이션을 효율적으로 수행하기 위한 다양한 알고리즘을 제시하고, 실무자가 이들을 손쉽게 활용하기 위한 역방향 시뮬레이션 도구를 소개한다. 실무자는 본 도구를 바탕으로 다양한 역방향 시뮬레이션 알고리즘을 활용하여 국방체계 설계를 위한 역방향 시뮬레이션을 손쉽게, 또 효율적으로 수행할 수 있다. 전함의 방어 시스템 설계와 군사 네트워크 시스템 설계에 대한 사례 연구는 이를 입증한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1096-1099
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• 2001

The basic design structure of RC-GCTs (Reserve-Conducting Gate-Commutated Thyristors) is firstly given in this paper. The bulk of wafer is punch-through (PT) type with high resistivity and narrow N-base width. The photo-mask was designed upon the turn-off characteristics of GCT and solution of separation between GCT and diode part. The center part of Si wafer is free-wheeling diode (FWD) and outer is GCT part which has 240 fingers totally. The switching performance of GCT was investigated by Dessis of ISE. The basic manufacture process of 2500V-4500V RC-GCTs was given in this work. Additionally, the local carrier lifetime control by 5Mev proton irradiation was adopted so as to not only to have the softness of reverse recovering for FWD but for reduction of turn-off losses of GCT as well.