• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권10호
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• pp.1830-1840
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• 2011

CDISC (Clinical Data Interchanging Standards Consortium) standards are to support the acquisition, exchange, submission and archival of clinical trial and research data. SDTM (Study Data Tabulation Model) for Case Report Forms (CRFs) was recommended for U.S. Food and Drug Administration (FDA) regulatory submissions since 2004. Although the SDTM Implementation Guide gives a standardized and predefined collection of submission metadata 'domains' containing extensive variable collections, transforming CRFs to SDTM files for FDA submission is still a very hard and time-consuming task. For addressing this issue, we developed metadata based SDTM mapping rules. Using these mapping rules, we also developed a semi-automatic tool, named CDISC Transformer, for transforming clinical trial data to CDISC standard compliant data. The performance of CDISC Transformer with or without MDR support was evaluated using CDISC blank CRF as the 'gold standard'. Both MDR and user inquiry-supported transformation substantially improved the accuracy of our transformation rules. CDISC Transformer will greatly reduce the workloads and enhance standardized data entry and integration for clinical trial and research in various healthcare domains.

• 한국환경과학회지
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• 제20권11호
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• pp.1499-1507
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• 2011

Practical disposal of transformer insulation oil laden with PCBs (polychlorinated biphenyls) by a chemical treatment has been studied in field work. The transformer insulation oil containing PCBs was treated by the required amounts of PEG (polyethylene glycol) and KOH, along with different reaction conditions such as temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. Removal efficiencies of PCBs in insulation oil before and after chemical treatment were examined. The removal efficiency of PCBs was very low at lower temperatures of 25 and $50^{\circ}C$. Under the reaction condition of PEG 600/KOH/$100^{\circ}C$/2hr, removal efficiency of PCBs was approximately 70%, showing completely removal of PCBs containing 7~9 chlorines on biphenyl frame which appear later than PCB IUPAC Number 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to $150^{\circ}C$ and 4 hours, removal efficiency of PCBs reached 99.99% without any formation of PCDDS/PCDFs during the process. Such reaction conditions were verified by several official analytical institutions. In studying the reaction of PEG with PCBs, it confirmed that the process of chemical treatment led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.625-630
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• 2005

In this paper, several energy recovery circuits (ERC) for the plasma display panel (PDP) are reviewed and classified in a manner of operation characteristics. A typical ERC using the Regenerative Transformer (RT) is introduced and compared with conventional ones. RT-ERC can achieve zero-voltage-switching (ZVS) for main full-bridge switches and zero-current-switching (ZCS) for the resonant switches and diodes. The charging/discharging energy of panel capacitance is efficiently recovered with the RT and without a sub-circuit. The presented circuit is verified with simulation and experimental results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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• pp.61-64
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• 2003

In the response to an increasing demand for electrical energy, much effort aimed to develop and commercialise HTS power equipments is going on around the world. For the development, it is necessary to establish the dielectric technology in $LN_2$. Hence many types of dielectric tests should be carried out to understand the dielectric phenomena at cryogenic temperature and to gather various dielectric data. Among the many types dielectric tests, the barrier effect were conducted with the simulated electrode after analysing the insulating configuration of the pancake coil type HTS transformer. The influence of a barrier on the dielectric strength was measured according to the size and the position of the barrier. It was shown that the effectiveness, the ratio of the breakdown voltage in presence of barrier to the voltage without barrier, is highest when the barrier is placed at the needle electrode side. And the barrier effect was not depend on the electrode array. The life time to breakdown with decreasing the applied voltage was increased remarkably having wide error band but the shape parameter in Weibull distribution was almost constant.

• 한국추진공학회지
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• 제3권4호
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• pp.12-22
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• 1999

Class-B 증폭기를 사용하는 가진기 시스템의 운용으로 인하여 다른 전자 시스템에 전자파 장해가 나타날 수 있으며, 이런 경우에 사용자가 이 장해를 해결하기 위하여 필요한 대책을 마련하기를 요구하고 있다. 한 가진기 시스템에서는 공통모드 잡음전압의 효과를 줄이기 위하여 Class-D 증폭기에서 차동증폭기가 사용되었고, 다른 가진기 시스템에서는 접지루프를 막기 위하여 변압기가 삽입되었다. 이 방법들은 이전에 발생하였던 불필요한 진동의 감소를 보여주고 있다. 전하증폭기의 변압기가 접지루프를 방지하기 위하여 Class-AB 증폭기를 사용한 가진기 시스템에서 수 년간 사용되었으나, Class-D 증폭기를 사용하는 가진기 시스템에서 이것은 잡음에 민감하였다. 따라서 전하증폭기와 진동 제어분석 시스템 사이의 접지루프를 변압기를 사용하지 않고 해결하였다. 이 방법의 유용성이 실험결과를 통하여 확인되었다.

• 정보처리학회 논문지
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• 제13권4호
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• pp.166-173
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• 2024

본 연구에서는 얼굴 동영상에서 입술의 움직임과 음성 간의 동기화 탐지 방법을 제안한다. 기존의 연구에서는 얼굴 탐지 기술로 얼굴 영역의 바운딩 박스를 도출하고, 박스의 하단 절반 영역을 시각 인코더의 입력으로 사용하여 입술-음성 동기화 탐지에 필요한 시각적인 특징을 추출하였다. 본 연구에서는 입술-음성 동기화 탐지 모델이 음성 정보의 발화 영역인 입술에 더 집중할 수 있도록 사전 학습된 시각적 Attention 기반의 인코더 도입을 제안한다. 이를 위해 음성 정보 없이 시각적 정보만으로 발화하는 말을 예측하는 독순술(Lip-Reading)에서 사용된 Visual Transformer Pooling(VTP) 모듈을 인코더로 채택했다. 그리고, 제안 방법이 학습 파라미터 수가 적음에도 불구하고 LRS2 데이터 세트에서 다섯 프레임 기준으로 94.5% 정확도를 보임으로써 최근 모델인 VocaList를 능가하는 것을 실험적으로 증명하였다. 또, 제안 방법은 학습에 사용되지 않은 Acappella 데이터셋에서도 VocaList 모델보다 8% 가량의 성능 향상이 있음을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.347-350
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• 2006

The high efficiency full-bridge LLC resonant converter using a contact-less transformer is proposed for the photovoltaic power generation system. For the series resonance with a series capacitor, the LLC resonant converter utilizes the leakage inductance and magnetizing inductance of a contact-less transformer. Unlike the conventional series resonant converter operated to the continuous resonant current at above resonance frequency, the proposed converter operates to the discontinuous resonant current at the narrow frequency control range below resonance frequency. Due to the discontinuous mode resonant current, the proposed converter can be achieved the zero voltage switching (ZVS) in the primary switches and the zero current switching (ZCS) in the secondary rectification diodes without any auxiliary circuit. In this paper, the experimental results of the proposed full-bridge LLC resonant converter using a contact-less transfonner are verified on the simulation based on the theoretical analysis and the 150W experimental prototype.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.2021_2022
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• 2009

Partial discharges(PD) is a important factor to evaluate the insulation state in high voltage electric machinery. However, measuring PD under the circumstances of power plant is occasionally impossible due to the relatively high magnitude of noise which is emanated from the operating machinery. In some case, the instrument measuring PD can not even perform a calibration that initializes tools and enhance the accuracy. This paper presents that we devised a noise reduction method and demonstrated the usefulness in acquiring reliable PD signals. We attached a series of filter and transformer at the input of power source of the instruments which refrains high noise signals from incoming to the instruments. We experimented the efficiency of noise reduction applying the device into the Dangjin Power Plant and Factory. As a result of testing with the filter and transformer, we can easily calibrate the PD signal compared to the case without the device. Additionally, we can detect the small PD signal which was unperceived with a normal device.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.67-75
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• 2013

In this paper, parallel input/serial output dual converter is designed appropriately for fuel cell hybrid power system. In case of proposed converter, zero voltage switching condition is designed without additional resonance device using leakage inductance of transformer and output capacitance of switch, and zero voltage switching method is used. Also, the system method is for increasing power by connecting half-bridge in parallel and increasing output voltage by connecting secondary output of transformer in serial. Through this method we can increase power and decrease volume of system. So in this paper, dual converter is designed. 1.5kW fuel cell hybrid power system was implemented, and system operation and stability was verified through experiment.

• 전기학회논문지P
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• 제57권2호
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• pp.153-159
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• 2008

We have developed an absolute evaluation method to obtain the ratio error and phase displacement of a current transformer (CT) without any precise standard CT by measuring four parameters in a CT equivalent circuit. The excitation admittance in the CT equivalent circuit can be obtained by employing standard resistors with negligible reactive component. The secondary leakage impedance in the CT equivalent circuit can be measured using a universal impedance bridge. The method was applied to CTs under test with the wide current ratios in the range of 5 A / 5 A - 5,000 A / 5 A and 5 A / 1 A - 5,000 A / 1 A. The ratio error and phase displacement of the CT under test obtained in this study are consistent with those measured at the national institute in Canada using the same CT under test within an expanded uncertainty (k = 2) in the overall current ratios.