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.

A Study on the Development of Fishing Vessels Safety Technology in Aceh Province of Indonesia for Korea's ODA

김경석,장은규,Kim, Kyong-Suk,Jang, Eun-Kyu The Korean Society of Marine Environment and safet 2010 海洋環境安全學會誌 Vol.16 No.2

Korea has recently joined the Development Assistance Committee (DAC) and currently implements a policy of vastly expanding the size of ODA. Indonesia has highly possessed growth potential in terms of vast quantity of natural resources, cheap labor force, and large local markets. Researches on how to support the Special Territory of Aceh province were made in this study. There is a necessity to increase the capacity of matter to the fishermen, and support facilities and infrastructure assistance to support the safety system in the sea. 우리나라는 최근 대개도국 지원국가(DAC)에 가입하여 공적원조(ODA)의 규모를 확대하고 있다. 인도네시아는 많은 부존자원과 값싼 노동력, 큰 현지시장을 갖고 있어 큰 잠재 성장력을 갖고 있다. 특히 인도네시아의 특별자치주인 아체지역은 쓰나미로 인해 큰 피해를 입었으며, 역사적으로도 많은 어려움을 겪은 지역이어서 우리나라의 원조를 희망하고 있다. 본 연구에서는 아체지역에서 필요로 하는 어선 안전에 관한 시스템과 설비 및 인프라에 대해 기술하고 이 지역에 대한 효과적인 개발 및 지원 방안을 제시하였다.

고객의 든든한 기술동반자

김경석,Kim, Gyeong-Seok 한국제품안전협회 2006 제품안전 Vol.4 No.-

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.

열화상기술을 이용한 모멘트 변화에 따른 피로균열진전 연구

김경석,정현철,박찬주,정덕운,장호섭,Kim, Kyeong-Suk,Jung, Hyun-Chul,Pack, Chan-Joo,Jung, Duk-Woon,Chang, Ho-Sub 한국생산제조학회 2010 한국생산제조학회지 Vol.10 No.6

The objective of this study is to propose an effective method for measurement and analysis of fatigue crack. A technique that can measure the statue of fatigue crack propagation fast and correctly for enhancing safety of constructions and securing reliability is necessary. Moreover, the crack propagation behavior characteristics evaluation technique has to be developed using this technique. In this paper, fatigue crack was caused via the fatigue experiment with repeated load on the CT specimen that is made up of STS304. Fatigue crack propagation was measured by tracing the position of the maximum temperature according to the cycles using infrared thermography. The crack growth characteristics was evaluated by applying the moment values on the measuring area to the measured value. As a result of this study, the possibility that the infrared thermography could be applied to measure the fatigue crack was identified. Moreover, it was identified that fatigue crack propagation have a relationship with the moment value of construction.

ESPI를 이용한 자외선조사량에 따른 폴리머애자의 탄성계수 변화 연구

김경석,김동수,장호섭,박찬주,장완식,정현철,Kim, Kyeong-Suk,Kim, Dong-Soo,Chang, Ho-Sub,Pack, Chan-Joo,Jang, Wan-Sik,Jung, Hyun-Chul 한국생산제조학회 2010 한국생산제조학회지 Vol.25 No.6

Recently, environment problems have effects on the electronic equipments. Security problems are presented. For security reasons, it is necessary to study electronic equipments. In this paper, we handle the Elasticity modulus on the polymer insulator by UV irradiation. The types of material are used in this experiment, is the EPDM (Ethylene Propylene Diene Monomer). For increasing the reliability, real material specimens are used. For this study, we used ESPI (Electronic speckle pattern interferometry), UTM (Universal thesting machine) device, Accelerated weathering tester. Through this measurement, we evaluated how much UV irradiation has effect on polymer insulator and how long does it take to change the polymer insulator. Also this paper will give a help in electronic industry and the method of measuring the insulator elasticity modulus of polymer could be utilized in life estimation and replacement time of the products of electronic equipment that is used in real industrial fields.

MB-OFDM UWB 신호 간섭하에서 SFBC/SFTC-OFDM 시스템들의 성능 비교

김경석,송창근,Kim, Kyung-Seok,Song, Chang-Kun 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.10A

고속 데이터 전송을 위하여, 송수신단에 다중 안테나를 사용함으로써 독립적인 페이딩 채널을 다수개 형성하여 다이버시티 이득과 코딩 이득을 동시에 얻는 MIMO(Multiple-Input Multiple-Output) 방식에 대한 연구가 활발히 진행되고 있다. 하지만 아직 UWB(Ultra Wide Band) 시스템과의 간섭에 대한 분석은 이루어지고 있지 않다. 이에 본 논문에서는 공간 다이버시티 특성을 가진 블록 코드를 OFDM 시스템에 적용하여, MIMO-OFDM 수신기에 인접한 UWB 기기로부터 SFBC(Space Frequency Block Code)-OFDM 시스템과 SFTC(Space Frequency Trellis Code)-OFDM 시스템에 .미치는 간섭 영향을 MIMO 채널 환경에서 성능을 분석하였다. 시뮬레이션 결과 SFTC-OFDM 시스템이 MB(Multi Band)-OFDM UWB 간섭에 대해 SFBC-OFDM 시스템보다 더 강인한 성능을 보여주었다. Research about the mode of MIMO that can get a coding benefit at the same time with a diversity benefit using a multiple antenna at the fading channel for a high-speed data transmission have been processed actively But the analysis about the interference of UWB system comes not to consist yet. So this paper analyzed the performance of the interference of UWB system to SFBC-OFDM and SFTC-OFDM system that applied a space block code which has a space diversity characteristic to OFDM system at MIMO channel. We shelved the performance that SFTC-OFDM system is robuster than SFBC-OFDM system under MB-OFDM UWB Interference.

폐유리와 산화 그래핀을 사용한 시멘트 모르타르의 물성 연구

김경석,추용식,Kim, Kyoungseok,Chu, Yongsik 한국자원리싸이클링학회 2019 資源 리싸이클링 Vol.28 No.6

This study investigated on the compressive strength and the length change test with using the waste glass and graphene oxide for recycling the waste glass as the aggregate. Curing on 3-day and 7-day, the compressive strength was enhanced as the usage of waste glass was increased. Especially, the huge difference in the compressive strength was observed when the amount of substituting on the waste glass was used on 10~50%. With 50% of waste glass condition, the compressive strength was portionally enhanced as the usage of graphene oxide was increased and its value was 42.6 N/㎟ with 0.2% of graphene oxide. In terms of the length change test, the use of high content of waste glass led length change value to increase, but it was dropped down as the portion of waste glass was above 50%. Furthermore, in the case of using 50% of waste glass, the use of high amount of graphene oxide tended to decrease the length change value. That is, graphene oxide may contribute on boosting the cement hydration reaction and blocking the ion's movement.

기후변화를 고려한 홍수방재시설물의 경제성분석 : 임진강 유역사례

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

임진강 유역은 1996년부터 1999년까지 3번의 대규모 홍수가 발생하여 많은 인명피해와 9천억원의 재산피해를 입었다. 우리나라는 기후변화로 인하여 홍수피해가 앞으로 증가할 것으로 예상된다. 본 연구는 기후시나리오를 활용하여 미래의 홍수피해를 예측하고, 실물옵션 기반 경제성분석 방법을 제시하였으며, 임진강유역의 홍수방지시설물 투자사업의 사례연구를 통해 경제성분석을 실시하였다. RCP (Representative Concentration Pathway) 기후시나리오에서 모의된 강수량 자료를 활용하여 홍수피해액을 계산하고, 홍수방지시설물 투자에 의한 저감이익을 분석하였다. 향후 RCP8.5와 RCP4.5 기후시나리오가 실현되는 조건을 가정하여 홍수피해 저감이익의 변동성을 구하고, 2071년에 200년 재현주기에 적응하도록 하는 확장을 위한 투자를 할 수 있는 확장옵션을 적용하여 프로젝트의 옵션가치를 구했다. 옵션가치 분석결과, 두 가지 시나리오 하에서 경제성을 확보하고 있음을 확인하였고, RCP8.5 기후시나리오가 실현될 때가 RCP4.5의 경우보다 홍수피해 저감이익이 더 많이 발생하였다. 본 연구는 정부 의사결정권자가 실물옵션분석방법을 활용하여 홍수방재시설물의 경제성분석에 기후변화 불확실성을 고려할 수 있도록 도와줄 것으로 기대되며, 기후시나리오에서 제공하는 강우자료를 활용하여 기후위험요소를 경제적 가치로 정량화하는 방법을 제시하였다. In Imjin River basin, three floods occurred between 1996 and 1999, causing many casualties and economic losses of 900 billion won. In Korea, flood damage is expected to increase in the future due to climate change. This study used the climate scenarios to estimate future flood damage costs and suggested a real options-based economic assessment method. Using proposed method, the flood control infrastructures in Imjin River basin were selected as a case study site to analyze the economic feasibility of the investment. Using RCP (Representative Concentration Pathway) climate scenarios, the future flood damage costs were estimated through simulated rainfall data. This study analyzed the flood reduction benefits through investment in the flood control infrastructures. The volatility of flood damage reduction benefits were estimated assuming that the RCP8.5 and RCP4.5 climate scenarios would be realized in the future. In 2071, the project option value would be determined by applying an extension option to invest in an upgrading that would allow the project to adapt to the flood of the 200-year return period. The results of the option values show that the two investment scenarios are economically feasible and the project under RCP8.5 climate scenario has more flood damage reduction benefits than RCP4.5. This study will help government decision makers to consider the uncertainty of climate change in the economic assessment of flood control infrastructures using real options analysis. We also proposed a method to quantify climate risk factors into economic values by using rainfall data provided by climate scenarios.