Investigation of Solvent Effect on the Electrical Properties of Triisopropylsilylethynyl(TIPS) Pentacene Organic Thin-film Transistors

김경석,김영훈,한정인,최광남,곽성관,김동식,정관수,Kim, K.S.,Kim, Y.H.,Han, J.-In,Choi, K.N.,Kwak, S.K.,Kim, D.S.,Chung, K.S. The Korean Vacuum Society 2008 Applied Science and Convergence Technology Vol.17 No.5

본 논문은 TIPS Pentacene을 유기반도체로 사용한 유기박막 트랜지스터의 용제에 따른 전기적 특성에 대한 연구로서, 용제로는 chlorobenzene, p-xylene, chloroform, toluene을 사용하였으며, 회전 도포 방법을 사용하여 TIPS pentacene을 혼합하여 적층하였다. chlorobenzene을 사용하여 만들어진 유기박막 트랜지스터는 $1.0{\times}10^{-2}cm^2/V{\cdot}s$의 전계효과 이동도, $4.3{\times}10^3$의 on/off 비율, 5.5 V의 문턱전압의 특성을 보였다. 반대로, chloroform을 사용하여 만들어진 유기박막 트랜지스터는 $5.8{\times}10^{-7}cm^2/V{\cdot}s$의 전계효과 이동도, $1.1{\times}10^2$의 on/off 비율, 1.7 V의 문턱전압의 특성을 보였다. 또한 각 용제에 따른 TIPS pentacene 결정크기를 AFM을 통하여 측정하였다. 이와 같은 결과들을 통하여, 더 높은 끊는점을 가진 용제는 TIPS Pentacene의 더 큰 결정 크기와 높은 결정화 성향으로 인하여 더 좋은 전기적 특성을 가지는 것을 확인할 수 있었으며, 본 실험에서는 끓는점이 가장 높은 chlorobenzene을 사용한 TIPS Pentacene 유기박막 트랜지스터가 가장 좋은 전기적 특성을 나타내는 것을 확인하였다. In this paper, we investigated the electrical properties of triisopropylsilyl (TIPS) pentacene organic thin-film transistor (OTFT) depending on solvent type. We spin coated TIPS pentacene by using chlorobenzene, p-xylene, chloroform, and toluene as solvents. Fabricated OTFT with chlorobenzene shows field-effect mobility of $1.0{\times}10^{-2}cm^2/V{\cdot}s$, on/off ratio of $4.3{\times}10^3$ and threshold voltage of 5.5 V. In contrast, with chloroform, the mobility is $5.8{\times}10^{-7}cm^2/V{\cdot}s$, on/off ratio of $1.1{\times}10^2$ and threshold voltage of 1.7 V. Moreover we measured the grain size of each TIPS pentacene solvent by atomic force microscopy (AFM). From these results, it can be concluded that a solvent with higher boiling point results in better electrical characteristics due to large grain size and high crystallinity of TIPS pentacene layer. In this paper TIPS pentacene with chlorobenzene shows the best electrical properties.

내반슬로 인한 대퇴경골각의 변화가 골반경사각에 미치는 영향

김경석,류지미,김고운,김귀현,정원석,이종수,Kim, Kyoung-Seok,Ryu, Ji-Mi,Kim, Koh-Woon,Kim, Gwi-Hyun,Jeong, Won-Seok,Lee, Jong-Soo 척추신경추나의학회 2009 척추신경추나의학회지 Vol.4 No.2

Objectives : The purpose of this study was to investigate the Correlation between Pelvic angle and the Tibiofemoral angle in the Genu varum. Method : Age of All subjects were 20-37 years. 33(male 10, female 23) subjects were assessed by whole spine x-ray and orthogram. The collected data consisted of items on general characteristics, Pelvic Incidence(PI), Pelvic Tilt(PT), Sacral Slope(SS) and Tibiofemoral Angle(TFA) of the subjects. Results : The PI, PT and TFA had a relationship significantly. However, there was no relationship between SS and TFA. Conclusion : The results suggest that TFA is related to PI, PT. Internal rotation due to genu varum of femoral at hip influence that PI and PT increase.

도로축별 안전개선사업의 현황과 발전방안

김경석,Kim, Gyeong-Seok 한국도로학회 2005 한국도로학회지 Vol.7 No.4

실물옵션 기법을 활용한 신재생에너지사업 경제성분석에 관한 연구

김경석,Kim, Kyeongseok 한국건설관리학회 2017 한국건설관리학회 논문집 Vol.18 No.2

기후변화의 영향으로 세계 각국은 화석연료 사용을 줄이고, 신재생에너지에 대한 투자가 활발하게 이뤄지고 있다. 세계 전력의 23.7%를 신재생에너지가 공급하고 있으며, 계속된 기술의 발전으로 화력설비와 발전원가 면에서 경쟁할 수준이 되어 투자 여건이 좋아 지고 있다. 하지만, 신재생에너지 프로젝트의 투자를 결정하는 것은 쉽지 않다. 본 연구는 신재생에너지 중에서 많은 비중을 차지하고 있는 수력, 태양광, 풍력발전 프로젝트 투자 결정에 실물옵션방법을 적용한 경제성평가에 대해 국내외 연구동향을 분석하였다. 본 연구는 (1)전통적 경제성분석방법과 실물옵션방법의 차이점, (2)적용 과정, (3)많은 연구들이 제시한 신재생에너지 프로젝트의 불확실성 요소들과 옵션종류에 대해 알아보았다. 실물옵션분석방법은 신재생에너지 프로젝트의 불확실성 요소들을 고려하고 수익을 향상시키거나 리스크를 피할 수 있는 옵션 적용이 가능하여 세밀한 투자계획수립에 적합하다. Due to climate change, countries around the world are actively investing in renewable energy, reducing fossil fuel use. 23.7% of world electricity is supplied by renewable energy. As the technology continues to develop, it is in a level to compete in terms of power generation cost, and investment conditions are improving. However, investment in renewable energy projects is not easy. This study analyzed trends of domestic and international researches on economics assessment applying real options analysis to investment decisions of hydro, solar, and wind power projects, which account for a large portion of renewable energy. This study provides (1) the difference between the traditional economic method and the real options analysis, (2) the application process, and (3) the uncertainty elements and option type of the renewable energy project presented by many studies. The real options analysis is suitable for the detailed investment strategy by considering the uncertainties of the renewable energy project and applying the option to improve the profit or to avoid the risk.

91년 석유수급정책방향

김경석,Kim, Gyeong-Seok 대한석유협회 1991 석유와 에너지 Vol.1991 No.3

억간산(抑肝散)의 항간질성(抗癎疾性) 효과(效果)에 대한 실험적(實驗的) 연구(硏究)

김경석,성강경,문병순,Kim, Kyung-Suk,Sung, Gang-Kyung,Moon, Byung-Soon 대한한방내과학회 1998 大韓韓方內科學會誌 Vol.19 No.1

This study has been carried out to investigate the effects of Ukgansan(UGS) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. UGS extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. UGS extract prolonged significantly the time to death induced by electrical shock of ECT unit.(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of UGS extract on the rectal temperature of mouse, UGS extract decreased significantly the rectal temperature of mouse 4. On the experiment of antipyretic effects of UGS extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mouse, UGS extract decreased significantly the rectal temperature of mouse. 5. On the experiment of analgesic effects of UGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mouse, the writhing syndrome induced by acetic acid was reduced significantly by administration of UGS extract. 6. On the experiment of effects of UGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of UGS extract. 7. On the experiment of effects of UGS extract on the activity of GABA-transaminase(GABA-T) in mouse brains after 21 days of oral administration of UGS extract. the activity of GABA-T was reduced significantly by administration of UGS extract. 8. On the experiment of effects of UGS extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of UGS extract, the activity concentration of GABA was reduced significantly by administration of UGS extract. 9 On the experiment of effect of UGS water extract on the activity of GAD in mouse brain after 21 days of oral administration of UGS extract, the activity of GAD was reduced significantly by administration of UGS extract. According to the these results, Ukgansan extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.

디지털 화상 상관법(DIC)의 원리

김경석,Kim, Kyeong-Suk 한국비파괴검사학회 2012 한국비파괴검사학회지 Vol.29 No.6

만성설사를 주소로 한 과민성 대장증후군 환자의 치험례

김경석,이상룡,김재훈,권도익,Kim, Kyung-sok,Lee, Sang-yong,Kim, Jae-hoon,Kwon, Do-ick 사상체질의학회 2001 사상체질의학회지 Vol.13 No.3

The irritable bowel syndrome(IBS) is the most common gastrointestinal disorder in clinical practice and is characterized by abdominal pain associated with a chronic disturbance of defecation. It is important to discriminate IBS from organic bowel disease. Based on clinical and epidemiologic studies, specific symptom criteria for IBS have been developed. The subject is a 29 year old man who has abdominal pain, chronic diarrhea, general weakness, dizziness, insomnia and has been diagnosed as irritable bowel syndrome. We classified this as Shaoyangin Mangyin(少陽人 亡陰證) and prescribed Hyeongbangjiwhangtang(荊防地黃湯) in accordance with the principle of pyoeumganggi(表陰降氣). In the result, we had the improvement of his symptoms.

실물옵션을 활용한 새만금 수상태양광 투자사업의 수익성 분석

김경석,Kim, Kyeongseok 한국건설관리학회 2021 한국건설관리학회 논문집 Vol.22 No.1

새만금개발은 1987년부터 30년간 정부가 농업, 경제와 관광지역으로 추진하고 있는 우리나라에서 가장 규모가 큰 국책사업이다. 우리나라는 원자력과 화력에 의존하던 전력원을 탄소저감을 위해서 친환경으로 전환하기 위해서 민관사업으로 우리나라 최대규모인 4.6조원을 투자하여 2.1GW의 수상태양광발전 프로젝트를 추진하고 있다. 새만금 수상태양광 프로젝트가 성공하려면 경제적 타당성을 확인해야 한다. 본 연구는 수상태양광사업의 변동성 요소들(건설비용, 전기판매가격, 발전량과 유지관리비용)을 정의하고, 20년간 운영하는 동안 수익의 변동성을 분석하였다. 불확실성으로 수익이 악화가 예상될 때 포기할 수 있는 권리를 가지는 포기옵션을 적용하여 프로젝트의 옵션가치를 구했다. NPV분석에 의하면 투자가 어려운 프로젝트가 옵션분석에 의하여 경제성을 확보할 수 있음을 확인하였다. 본 연구는 투자사업의 의사결정권자가 실물옵션분석방법을 활용하여 수상태양광프로젝트의 경제성분석에 불확실성을 고려할 수 있도록 도와줄 것으로 기대된다. Saemangeum Development is the largest national project in South Korea, which has been developed for an agricultural, economic and tourist area for 30 years from 1987. In order to convert power sources that used to depend on nuclear and thermal power to eco-friendly for carbon reduction, the government plans to construct a 2.1GW floating photovoltaic project by investing 4.6 trillion won, as a public-private project. For success of the Saemangeum floating photovoltaic project, economic feasibility should be checked. This study defined the factors (construction cost, electricity selling price, power generation and maintenance cost) that give a effect to the volatility of the floating photovoltaic payoffs, and analyzed the volatility of payoffs during 20 years operation period. NPV and option value of the project were calculated by applying an option to abandon. According to NPV analysis, it is determined that projects are difficult to invest. But this project has economic feasibility through real options analysis. This study is expected to help decision-makers in the economic analysis of floating photovoltaic projects by using the real options analysis.

고온하의 CW 레이져 스페클 사진법과 화상처리에 의한 열팽창계수 측정에 관한 연구

김경석,최정석,Kim, Gyeong-Seok,Choe, Jeong-Seok 한국정밀공학회 1992 한국정밀공학회지 Vol. No.

In resent year Laser Speckle and its development have enabled surface deformation of engineering components and materials to be interferometrically examined. Laser Speckle- Pettern Interferometry Method is a very useful method for measuring In-plane components of displacement. In measuring thermal expansion coefficient, the various problems generated were established, and the measuring limitation examined. Metarial INCONEL 601 was used in experiments. Specimen was heated to the high temperature(100$0^{\circ}C$) by diong current to the direct two specimen. Then, those problems appear to the influence of back-ground radiation by the heated specimen, the influence by air turbulence, the oxidation of specimen. The color monitor and interference filter prevented the back-ground radiation by rad heat. The oxidation occuring in specimen itself was not generated by the being acid-proof excellence of material INCONEL 601. Yet, in this experiments, the serious problems are the oxidation of specimen and influence by air turbulence. By more reserching these problems forward, it is helpful that the thermal expansion coefficient of many materials is directly measured under high temperature.