• 전력전자학회논문지
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• 제6권6호
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• pp.481-488
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• 2001

현재 AC-PDP(Plasma Disphay Panel) 의 기술은 급속히 발전하고 있는 추세이지만 아직도 몇가지 문제로 인해 이를 해결하기 위한 다각적인 접근이 이루어지고 있다. 동화상 윤곽의 제거 광(光) 대비 향상을 통한 화질의 개선 신뢰도 및 전력 효율을 개선하는 등의 문제가 여기에 해당되며 그 중에서도 특히 전력 효율의 관점에서 40 인치 이상의 대형화면을 지향한는 PDP 기술에서 가장 큰 약점으로 분류되고 있는 수백 와트(watt)에 이르는 전려 소모를 CRT 수준이 200[W] 미만으로 낮추어 것이 시급한 당면 과제이다. 전려 효율을 향상시키기 위해서 PDP의 발광효율을 높이는 것과 함께 기체 장번과는 직접적인 관련이 없이 구동과정시 발생하게 되는 불필요한 전력소모를 최소화 하여야 한다. 본 논문에서는 이러한 전력 소모를 최소화하기 위한 새로운 형태의 고효율 에너지 회수 회로를 제안하고 시뮬레이션을 통해 그 동작을 확인하였다. 또 이는 회로를 설제 7.5인치 패널에 인가하고, 200［kHz］에서 실험하여 제안한 고효율 에너지 회수회로의 타당성을 검증하였다.

• 임상간호연구
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• 제14권3호
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• pp.15-25
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• 2008

Purpose: This study was aimed to investigate the effects of gum-chewing on the recovery of bowel movement and oral cavity discomfort after abdominal surgery. Method: The nonequivalent control group, non-syncronized repeated treatment design was used. A total of 99 patients were participated in the study. The 44 patients were in the experimental group and the rest in the control group. The experimental group chewed gum three times a day until they passed gas. As the patient reported gas-passing, bowel movement time, subjective symptoms of oral cavity, and oral status were recorded precisely. The frequency, percentage, $x^2$-test and t-test were analyzed by SPSS PC 12.0. Results: There were significant differences in bowel movement, gas passing, oral cavity symptoms, and oral status scores between the experimental and the control group. Conclusion: The findings of the study demonstrated the fact that gum-chewing helps early recovery from post-operative ileus and thirst. It is because gum chewing stimulates bowel mobility and secretion of saliva. Thus gum-chewing seems to be an effective nursing intervention in reducing post-operative side effects for patients with abdominal surgery.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권3호
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• pp.185-192
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• 2013

In this paper, a clock and data recovery (CDR) circuit that supports triple data rates of 1.62, 2.7, and 5.4 Gbps for DisplayPort 1.2 standard is described. The proposed CDR circuit covers three different operating frequencies with a single VCO switching the operating frequency by the 3-bit digital code. The prototype chip has been designed and verified using a 65 nm CMOS technology. The recovered-clock jitter with the data rates of 1.62/2.7/5.4 Gbps at $2^{31}$-1 PRBS is measured to 7/5.6/4.7 $ps_{rms}$, respectively, while consuming 11 mW from a 1.2 V supply.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1066-1074
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• 2015

This paper presents the reverse recovery characteristic according to the change of switching states when Si diode and SiC diode are used as clamp diode and proposes a method to minimize the switching loss containing the reverse recovery loss in the neutral-point-clamped inverter at low modulation index. The previous papers introduce many multiple circuits replacing Si diode with SiC diode to reduce the switching loss. In the neutral-point-clamped inverter, the switching loss can be also reduced by replacing device in the clamp diode. However, the switching loss in IGBT is large and the reduced switching loss cannot be still neglected. It is expected that the reverse recovery effect can be infrequent and the switching loss can be considerably reduced by the proposed method. Therefore, it is also possible to operate the inverter at the higher frequency with the better system efficiency and reduce the volume, weight and cost of filters and heatsink. The effectiveness of the proposed method is verified by numerical analysis and experiment results.

• 한국재난관리표준학회지
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• 제2권3호
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• pp.25-30
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• 2009

기후변화 동에 따른 세계 재해의 발생빈도 및 규모가 증가함에 따라 UN 등 국제사회에서는 피해지역에 대한 재해 복구 지원과 원조를 확대해 나가고 있다. 또한 저개발국가의 재해경감을 위한 다양한 지원프로그램을 추진하고 있어, 우리나라에서도 KOICA 프로그램의 활성화 및 체계적인 국제지원체계구축의 필요성이 대두되고 있다. 본 연구는 국제적 재해에 대한 UN 국제기구, 선진국가의 체계를 분석하여 우리나라가 효과적으로 지원할 수 있는 체계를 제안함으로써 국제사회의 재해경감 노력에 참여하고 국제 사회에서의 국가위상을 제고하고자 하였다.

• 한국의류학회지
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• 제35권7호
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• pp.787-800
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• 2011

This study investigated service recovery justice perception, purchase satisfaction, positive word-of- mouth (WOM) intention, and repurchase intention of fashion consumers according to the types of internet shopping malls. A survey was conducted from December 20 in 2010 to January 28 in 2011, and 324 respondents who had complaint with internet shopping malls were used in the data analysis. The statistical analysis methods were frequency analysis, factor analysis, reliability analysis, t-test, ANOVA, and multiple regression analysis. The results of this study were as follows. First, in case of integrated internet shopping malls, the procedure justice influenced the purchase satisfaction and the interaction justice influenced the positive WOM intention. In addition, the distribution justice influenced the repurchase intention of fashion consumers. In the case of an open market, the interaction justice influenced the purchase satisfaction and the distribution justice influenced the positive WOM intention. In case of specialized internet shopping malls, the distribution justice influenced the purchase satisfaction and the interaction justice influenced the repurchase intention. Second, there was a difference in the procedure justice, positive WOM intention, and repurchase intention according to gender.

• 정보처리학회논문지A
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• 제11A권5호
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• pp.313-318
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• 2004

본 논문에서는 장시간 실행이 예상되는 결함 허용 프로세스를 위한 검사점 및 복구 도구를 제시한다. 제시한 도구의 기본 개념은 프로세스의 실행 상태를 주기적으로 저장함으로써 시스템 결항으로 인해 실행이 정지되었을 경우, 결함이 발생하기 전의 실행 상태를 복구하여 계속 실행시키는 것이다. 제시한 도구에서는 검사점 및 복구를 위하여 결함 허용 프로세스의 소스 코드를 수정할 필요가 없다. 이를 위하여 결함 허용 프로세스를 위한 파일명과 검사점 주기를 사용자가 직접 지정하도록 설계하고, 두 개의 시스템 호출(Save, recover)을 추가하였다. 마지막으로 제시한 기법의 타당성을 검토하기 위하여 리눅스 환경(커널 2.4.18)에서 구현하였다.

• ETRI Journal
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• 제35권3호
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• pp.386-396
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• 2013

A 10-Gbit/s wireless communication system operating at a carrier frequency of 300 GHz is presented. The modulation scheme is amplitude shift keying in incoherent mode with a high intermediate frequency (IF) of 30 GHz and a bandwidth of 20 GHz for transmitting a 10-Gbit/s baseband (BB) data signal. A single sideband transmission is implemented using a waveguide-tapered 270-GHz high-pass filter with a lower sideband rejection of around 60 dB. This paper presents an all-electronic design of a terahertz communication system, including the major modules of the BB and IF band as well as the RF modules. The wireless link shows that, aided by a clock and data recovery circuit, it can receive $2^7$-1 pseudorandom binary sequence data without error at up to 10 Gbit/s for over 1.2 m using collimating lenses, where the transmitted power is 10 ${\mu}W$.

• Journal of Power Electronics
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• 제15권6호
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• pp.1489-1498
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• 2015

Gallium nitride (GaN)-based power switching devices, such as high-electron-mobility transistors (HEMT), provide significant performance improvements in terms of faster switching speed, zero reverse recovery, and lower on-state resistance compared with conventional silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFET). These benefits of GaN HEMTs further lead to low loss, high switching frequency, and high power density converters. Through simulation and experimentation, this research thoroughly contributes to the understanding of performance characterization including the efficiency, loss distribution, and thermal behavior of a 160-W GaN-based synchronous boost converter under various output voltage, load current, and switching frequency operations, as compared with the state-of-the-art Si technology. Original suggestions on design considerations to optimize the GaN converter performance are also provided.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.90-95
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• 2015

This paper describes IEC 61727 standard of Photovoltaic (PV) systems -Characteristics of the utility interface. IEC 61727 standard tests include utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1) voltage, current and frequency, 2) normal voltage operating range, 3) flicker, 4) DC injection, 5) normal frequency operating range, 6) harmonics and 7) waveform distortion, 8) power factor of PV inverter. Also personnel safety and equipment protection part includes test items 1)loss of utility voltage, 2)over/under voltage and frequency, 3)Islanding protection, 4)response to utility recovery, 5)earthing, 6)short circuit protection, 7)Isolation and switching of PV inverter. In this paper, each item of IEC 61727 standard test is studied and analyzed and finally full tested by PV inverter performance function.