Organic Solar Cells: Solution‐Processable Reduced Graphene Oxide as a Novel Alternative to PEDOT:PSS Hole Transport Layers for Highly Efficient and Stable Polymer Solar Cells (Adv. Mater. 42/2011)

Yun, Jin‐,Mun,Yeo, Jun‐,Seok,Kim, Juhwan,Jeong, Hyung‐,Gu,Kim, Dong‐,Yu,Noh, Yong‐,Jin,Kim, Seok‐,Soon,Ku, Bon‐,Cheol,Na, Seok‐,In WILEY‐VCH Verlag 2011 Advanced Materials Vol.23 No.42

<P>Solution‐processable reduced graphene oxide as a hole‐transporting layer for highly efficient and stable organic solar cells is reported on page 4923 by Dong‐Yu Kim, Seok‐In Na, and co‐workers. Introduction of a newly reduced graphene oxide by simple solution processing into solar cells dramatically raises the cell efficiency and cell life‐time. The results will allow full use of chemically reduced graphene and will advance the realization of carbon‐based printable optoelectronic devices. </P>

A Study on the Miniaturization of a Protective Device for the Micro Smart Grid Simulator

Yun‑Seok Ko,Kyung Ryu,Min‑Soo Oh,Hyuk‑Sik Yoon 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

In this paper, a miniaturization methodology of protective devices (PDs) was proposed which plays a key role in evaluating the efectiveness of the developed protection and control algorithms in the micro smart grid simulator. The micro PD was designed to have the rated voltage of 19 V and the breaking current of 20 A, and was designed in a multi-layered hardware structure to satisfy the size of 13×13 cm2 . Also, the micro PD was designed in a multifunctional structure to allow one micro PD to perform all the functions of the circuit breaker, recloser and switches on the micro smart grid simulator to enhance the efciency of development. Finally, it was verifed that the developed micro PD can be applied as protective devices of the micro smart grid simulator by showing that it operates correctly according to the predetermined operation sequence for the test scenarios on the built test system.

Estimation of the Extreme Value Index Ⅱ : Efficiency Optimal Estimators 효율 및 최적 추정량

Yun, Seok Hoon 수원대학교 기초과학연구소 1997 基礎科學論文集 Vol.6 No.-

극단값 지수의 추정량으로서 Falk(1994)가 제시한 추정량과 Yun(1997)이 제시한 추정량은 모두 Pickands 추정량의 저효율을 개선시키는 효과가 있다. 본 논문에서는 Falk의 추정량과 Yun이 제시한 추정량이 각기 최적의 방법으로 선택되었을 경우 점근적으로 동일한 효율을 가짐을 보인다. 또한, 유한표본의 경우 시뮬레이션을 통하여 Yun의 추정량이 Falk의 추정량보다 우수함을 보인다.

Gilbert 증후군에서 열량 제한 시험과 Phenobarbital 자극 시험의 의의(14예)

이헌영,채경훈,정재훈,강윤세,김연수,문희석,박기오,이엄석,김선문,김석현,성재규,이병석,이강욱 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Gilbert 증후군은 인구의 7%에서까지 나타날 수 있는 매우 흔한 증후군으로서 비진행성인 양성의 만성적 경과를 치하며, 간질환의 증상과 징후가 없는 경한 비포합형 고빌리루빈혈증이 특징인 일종의 체질적인 증상으로서 혈장 빌리루빈 농도에 대한 사춘기의 영향 때문에 10대와 20대에 자주 진단이 된다. 따라서 임상적인 중요성은 미약하지만 높은 빈도가 예상되는 점에 그 중요성이 부여되어야 할 것이다. 따라서 적정한 임상적 진단법으로 기왕에 소개된 열량제한 시험과 phenobarbital 유도 시험을 시행하고 이들의 진단적 가치를 알아보기 위하여 본 연구를 시행하였다. 1990년 7월부터 1999년 4월까지 충남대학교병원에 내원하여 HBsAg, IgG anti-HBc 및 anti-HCV가 음성이고, 간 초음파 스캔에서 이상이 없으며, 혈청 AST, ALT 및 AP가 정상인 비음주자에서 경한 비포합형 고빌리루빈혈증이 있는 14예의 환자들을 대상으로 ^(99m)Tc-DISID 스캔을 시행하였으며, 기저 치 총빌리루빈 및 포합형 빌리루빈 치를 측정한 다음에 하루에 400Kcal로 48시간동안 제한한 열량 제한 시험을 시행하였고, phenobarbital을 하루 60mg씩 5일간 투여한 후에도 각각 총빌리루빈과 포합형 빌리루빈 치를 검사하여 비포합형을 구하였다. 대상 환자들은 모두 14예로서 남자가 11예(78.6%)였고 여자가 3예(21.4%)여서 3.7:1로 남자에서 많았으며, 20대가 6예(42.9%), 30대가 역시 6예(42.9%) 및 40대가 2예(14.2%)로서 2,30대가 대부분(85.8%)이었다. 열량 제한 시험 후의 총빌리루빈 치, 비포합형 및 포합형 빌리루빈 치들은 평균 각각 5.5±2.7, 4.2±2.3 및 1.3±10mg/dL 로서, 시험 전 치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg/dL 보다 유의하게(p=0.001, p=0.001, p=0.023) 상승하였다. 포합형 빌리루빈 치도 유의하게 상승하였으나 비포합형의 상승보다는 훨씬 낮아서 주로 비포합형이 증가하였다. phenobarbital 투여 중 설사가 발생하여 중단한 1예를 제외한 13예에서 열량 제한 시험 후에 상승하였던 총, 비포합형 및 포합형 빌리루빈 치가 phenobarbital 유도 시험후에는 2.0±1.1, 1.5±0.8 및 0.5±0.4mg/dL로서 열량 제한 시험 결과보다 유의하게 낮아졌고(p=0.00, p=0.000, p=0.001), 열량 제한 시험 전의 기초치들인 3.0±0.8, 2.2±0.8 및 0.7±0.4mg.dL 보다도 더욱 낮아졌으며 유의한 차이(p=0.001, p=0.02, p=0.005)를 나타내었다. 14예에서 시행한 ^(99m)-Tc DISIDA 스캔에서 9예(64.3%)가 정상이었고, 5예(35.7%)에서는 심장 및 신장으로의 간외 섭취가 3예였고, 60분까지 소장 배출이 없는 배설 지연 예와 담낭 수축 불량 예가 각각 1예 씩 발견되었다. Phenobarbital 투여시험에서 민감도가 열량제한시험에 비해 더 높았다(92.3%와 50.0%). Gilbert 증후군에서 1일 400 Kcal로 48시간의 열량제한 시험과 1일 60mg의 phenobarbital을 5일간 투여하는 유도 시험은 편리하고 유용한 임상적인 진단법으로 이용할 수 있다고 생각된다. 그러나 열량 제한 시험에서는 증가 기준의 통일이 필요하다고 유추되며 phenobarbital 유도 시험이 민감도가 더 높은 것으로 생각된다. Gilbert's syndrome is very frequent and benign chronic process characterized by mild, intermittent, unconjugated hyperbilirubinemia without any symptom and sign of liver disease. Previously intoduced caloric restriction test and phenobarbital stimulation test as two appropriate clinical tests had been examined and their diagnostic values were reevaluated. Fourteen patients with mild, persistent, unconjugated hyperbilirubinemia were included. Subsequently caloric restriction has been applicated by 400 Kcal/day for 48 hours and phenobarbital has been prescribed by 60 mg/day for 5 days. Therafter serum levels of total and direct bilirubin were measured. Most of the patients were third and fourth decade(85.8%) and male predominant. Each basal serum levels of total, indirect and direct bilirubin were 3.0±0.8, 2.2±0.8 and 0.7±0.4 mg/dL. After caloric restriction test, each levels were increased significantly to 5.5±2.7, 4.2±2.3 and 1.3±1.0 mg/dL(p=0.001, p=0.001, p=0.023). After phenobarbital stimulation test for 13 patients had been practiced, increased levels of each bilirubin after caloric restriction test were decreased significantly to 2.0±1.0, 1.5±0.8 and 0.5±0.4 mg/dL(p=0.000, p=0.000, p=0.001) and these levels were significantly lower than basal levels(p=0.001, p=0.02, p=0.005). The sensitivities of caloric restriction test were 85.7%, 50.0%, and 71.4%, 35.7%(1.0, 1.5 mg increase of total bilirubin and 1.0, 1.5 mg/dL increase of indirect bilirubin). The sensitivities of phenobarbital stimulation test were 93.2% and 92.3% at criteria of 1.5 mg/dL increase of total bilirubin and indirect bilirubin. On the diagnosis of Gilbert syndrome, caloric restriction test and phenobarbital stimulation test are convenient and useful diagnostic tools in clinical face. And also phenobarbital stimulation test has higher sensitivity than caloric restriction test. Furthermore, standardization of bilirubin increment would be necessary in caloric restriction test.

순천향대학교 천안병원에 입원한 로타바이러스 감염 위장관염 환자의 임상양상

최석주,전세윤,김승수,박경배,김용배,박준수 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

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급성 뇌경색 환자에서 경색 위치가 심근 효소치 상승에 미치는 영향

윤경호,박현영,박성욱,장혁,김요식,조광호,유남진,김남호,오석규,정진원 圓光大學校 醫科學硏究所 2003 圓光醫科學 Vol.18 No.2

저압 아크 고장 차단 기술에 대한 기초 조사 연구

고윤석 남서울대학교 2008 남서울대학교 논문집 Vol.14 No.-

The ELCB(Earth Leakage Circuit Breaker) determines whether the earth leakage is or not by comparing the sensitive current furnished from ZCT(Zero Current Transformer) with the predefined threshold value. However, it can not recognize the arc fault in which the magnitude of fault current is very small and so, the arc fault is expanded into very severe electrical fire. The America has propelled making the laws for the arc fault protection from 1999, and NEC(National Electrical Code) defines and mandates the installation of the AFCI(Arc Fault Current Interrupter)s in diverse places such as bedroom, living room, dinner room, sunroom and closets in 2008. GE and Siemens developed the determination technology of arc fault by making R&D effort for AFCI practicalization, and to mitigate the electrical fire, the developed AFCIs are applied widely to home. However, the effort of us about this field is insufficient, and the level also is very low. Accordingly, this paper surveys and analyzes systematically the basic technology needed in developing the arc fault determination technology. Key Words : AFCI, Electrical Panel, ELCB, ZCT, NEC

비선형 웹 이송 시스템의 장력제어

윤석찬,백승훈,정진태,한창수 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.5

This paper presents the study of the tension control in a web transfer system. In this study the sliding mode controller is applied to a time-varying nonlinear mathematical model. The model was derived to consider the effects of changing the roll rad;us in tension variation during winding and unwinding. The uncertainty in modeling may be due to unmodelled dynamics, on variations in system model. Designed sliding mode controller made the system error always staying in the suggested surface from the beginning. Through this, system is maintained to be robust against a disturbance and uncertainty. To verify the designed controller has a good performance, various inputs such as desired velocity, step input, and trapezoidal input are applied. When the sliding mode controller was used, the system(the tension control) performance was improved comparing to the PID controller. The robustness of the controller with respect to an estimation error was verified through simulations.

수냉쿨러의 냉각 효율 향상을 위한 플레이트 부품의 형상에 관한 연구

성윤호,김형찬,김선민,윤석영,이영웅,이상욱 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

This study investigates changes in cooling efficiency for heat sink plate width, perforated width, and chamfer angle as part of a parameter study to maximize cooling efficiency of heat sink by setting various variables on plates. The width of the plate is set to 16, 20, 24, 28 mm, perforated width 1.5, 2.0, 2.5 mm, chamfer angles 5, 10, 15 and 20°. By conducting a computational study with Ansys Fluent, the sink plate with plate width of 16mm, perforated width of 3mm and chamfer angle of 10° is shown to be the best cooling efficiency.

이산 프리에 변환(DFT)기법의 배전계통 HIF 해석 적용을 위한 기초기술 연구

고윤석 남서울대학교 2007 남서울대학교 논문집 Vol.13 No.3

ABSTRACT : It is very difficulty to detect the HIF(High Impedance Fault) ofdistribution system is very difficulty because that the current variation isvery little by high impedancefault circuit. And, the spread effect of thefault is very severe including a loss of human lives. Accordingly, in thispaper, the HIF analysis methodology of distribution is studied on thebased on DFT(Discrete Fourier Transformation). At first, the main topicsare analyzed such as the typical distribution configuration, diversityevents and DFT. The basic technology for the detection of HIF ofdistribution system basedon DFT method is analyzed by applying theDFT method to the real measured HIF waveform. Here, the waveform isobtained bygenerating the artificial HIF using an artificial faultequipment.