채널의 길이가 짧은 NMOS 트랜지스터의 Threshold 전압과 Punchthrough 전압의 감소에 관한 실험적연구

이원식,임형규,김보우,Lee, Won-Sik,Im, Hyeong-Gyu,Kim, Bo-U 대한전자공학회 1983 전자공학회지 Vol.20 No.2

MOS 트랜지스터의 채널이 짧아짐에 따라 threshold 전압과 punchthrough 전압이 감소하는 현상을 실리콘 게이트 NMOS 기술로 제작한 소자로써 실험적으로 관찰하였다. 또한 게이트 산화막의 두께를 50nm와 70nm로 감소시키고 보론(boron)을 임플랜트한 소자를 제작하여 게이트 산화막의 두께와 서브스트레이트의 불순물의 농도가 threshold 전압과 Punchthrough 전압의 감소에 미치는 영향을 측정하였다. 또 채널의 길이가 3㎛인 소자에 대하여 hot-electron의 방출을 플로우팅 게이트 패준 방법에 의하여 측정하였으며 그 결과 채널의 길이가 3㎛까지는 hot-electron의 방출은 문제가 되진 않음을 관찰하였다. The reduction of threshold voltage and punchthrough voltage of short channel MOS transistors has been measured experimentally with silicon gate NMOS transistors. The effects of the gate oxide thickness and substrate doping concentration on the threshold voltage and punch-through voltage have also been measured with sample devices with boron implantation and gate oxide thickness of 50 nm and 70 nm. Hot electron emission has been measured by floating gate method for the samples with 3 ${\mu}{\textrm}{m}$ channel length. It has been concluded from this measurement that hot electron emission is not significant for the channel length of 3${\mu}{\textrm}{m}$.

노인 입원환자에 대한 항궤양약물 처방양상 분석

이원식,이승미,구혜원,박병주,Lee, Won-Sik,Lee, Seung-Mi,Koo, Hye-Won,Park, Byung-Joo 대한예방의학회 2002 Journal of Preventive Medicine and Public Health Vol.35 No.1

Objectives : To review the drug prescription pattern of antiulcerative agents for elderly inpatients, Methods : The study population comprised inpatients of community hospitals who were members of the Korean Elderly Pharmacoepidemiologic Cohort (KEPEC), aged 65 years or over, beneficiaries of the Korea Medical Insurance Corporation (KMIC) and residing in Busan city in 1993. The drug prescription information was collected from the claims data of hospitals where the cohort members received medical care between January 1993 and December 1594. The information included personal identification, age, gender, diagnosis, drug dosage, date of hospital admission and name of medical institutions where the study subjects received drug prescriptions. The data analysis produced outcomes in terms of distribution of antiulcerative agents by class and by medical institution and trend of relative prescription, Analysis was also performed in terms of combined prescriptions of antiulceratives and drugs that could induce risk from drug interaction with antiulceratives. Results : The number of patients prescribed antiulcerative agents was 1,059 (64,9%) male and 1,724 (65.5%) female among the total inpatients. An antacid and composite agent was the most frequently prescribed antiulcerative agent (70.8%), followed by $H_2$ antagonist (16.0%), Among the potential drugs that could induce risk from drug interaction with the antiulcerative agents, diazepam was the most frequently prescribed. The proportion of diazepam co-prescription was 22.5% of the total cimetidine prescriptions and 14.5% of the fetal omeprazole prescriptions. Conclusions : Antiulcerative drugs were frequently prescribed in the elderly inpatients. The adverse drug reaction could possibly be due to drug interaction. The study results could be used as fundamental data for further drug utilization review of antiulceratiye agents.

한국(韓國)에서 발굴(發掘)한 고려해선(高麗海船)과 중국(中國) 봉췌(蓬萃) 제(第)3호고대선(號古代船)의 비교(比較) 고찰(考察)

이원식,허일,Lee, Won-Sik,Heo, Won 대한조선학회 2006 大韓造船學會誌 Vol.43 No.4

마이크로 분말사출성형에서 바인더 물성이 피드스탁 및 성형공정에 미치는 영향에 관한 연구

이원식,김용대,Lee, Won-sik,Kim, Yong-dae 한국금형공학회 2017 한국금형공학회지 Vol.11 No.3

The fabrication process of micro pattern structure with high precision and high aspect ratio using powder injection molding (PIM) is developed. In the PIM process, the metal powder is mixed with the binder systems and the mixture is injected into the metal mold. The injection molded green parts are debinded and sintered to reach final shape and properties. In this method, the optimization of physical properties such as fluidity and strength of the binder system is essential for perfect filling the high aspect ratio micro-pattern. For this purpose, the correlation between the properties of the binder system and feedstock and ${\mu}-PIM$ process was investigated, and a binder system with low viscosity at low temperature(about $110^{\circ}C$) and high strength after cooling was investigated and applied. Employing this process, high precision parts with line type micro pattern structure which has pattern size $160{\mu}m$ and aspect ratio more than 2 can be manufactured.

광섬유를 이용한 레이저섬광의 균일분포 증진효과에 따른 열확산계수 측정에 관한 고찰

이원식,배신철,Lee, Won-Sik,Bae, Shin-Chul 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.8

When thermal diffusivity is measured by laser flash method, the thermal diffusivity call be calculated front the assumption of the uniformly heated whole surface of the specimen. It has been known that the approximate 5% error is made by the non-uniform energy distribution on the specimen surface of laser pulse heat source. In this study, to obtain the highly-uniformed laser beam, which has both the low non-uniform heating error from non-uniform laser beam and the energy loss, research was carried out on no transmitting loss by optical fiber and high repetitions. In addition, heating error and thermal diffusivity were measured as the measuring positions were varied and compared with the results using the uniform and the non-uniform laser beams. In addition, dole to using the uniformalized laser beam, the whole surface of the specimen was heated uniformly and as a result, it was the thought that this was very effective to reduce the variations of the errors of the thermal diffusivity as the measuring positions were varied. It can be obtained that when the thermal diffusivity of POCO-AXM-5Q1 of SRM in NBS was measured with both the uniform and the non-uniform laser beams, the dispersion error of the former was from 2 to 2.5%, which was more improved than that of the latter.

SAFETY KOREA 제품안전 칼럼 - 일본의 제품사고 정보 활용법

이원식,Lee, Won-Sik 기술표준원 2011 기술표준 Vol.110 No.-

소비자의 안전을 위하여 우리나라에 "제품안전 기본법"이 있다면 일본에는 "소비생활용 제품안전법"이 있다. 일본에선 제품사고 정보를 어떻게 활용하는지 소비자에 대한 홍보를 중심으로 간단히 살펴보았다.

Cobalt Oxime Sandwich형 화합물을 합성하기 위하여 Oxime류와 (${\eta}^5$-Cyclopentadienyl)cobalt를 포함하는 착물과의 반응

이원식,이혁,변상인,박영배,이광,엄재국,곽영우,김태정,Won-Sik Lee,Hyuk Lee,Sang-In Byun,Young-Bae Park,Kwang Lee,Jae-Kook Uhm,Young-Woo Kwak,Tae-Jeong Kim 대한화학회 1992 대한화학회지 Vol.36 No.2

Cobalt 금속 중심으로 cyclopentadienyl을 ${\pi}$-착물로 결합하고, 또 oxime 화합물을 리간드로 하는 cobalt oxime sandwich형 착물을 합성하기 위하여 본 연구를 수행하였다. Cyclopentadienyl-cobalt 부분을 도입하기 위해, (${\eta}^5$-Cyclopentadienyl)bis(ethylene)cobalt (Jonas 시약), (η5-cyclopentadienyl)di(carbonyl)cobalt, 그리고 bis(${\eta}^5$-cyclopentadienyl)cobalt (cobaltocene)의 착물이 사용되었고, oxime을 각각 여러 가지 조건에서 반응시켰다. 그 중에서 Jonas 시약과 dienemonooxime인 2,4-hexadienealdoxime만이 반응되었으며, 그 생성물은 예상을 벗어난 (${\eta}^5$-cyclopentadienyl)(2,4-hexadienenitrile)cobalt [VII]로 밝혀졌다. 이 화합물의 구조는 NMR, mass spectrometer, IR 원소분석기를 통해 확인되었다. (${\eta}^5$-Cyclopentadienyl)bis(ethylene)cobalt (Jonas reagent), (${\eta}^5$-cyclopentadienyl)di(carbonyl)cobalt, and bis(${\eta}^5$-cyclopentadienyl)cobalt (cobaltocene) were reacted with oximes, respectively, under various conditions for synthesizing cobalt oxime sandwich complex. Jonas reagent and a dienemonooxime, 2,4-hexadienealdoxime underwent the reaction. This produced unexpected compound, (${\eta}^5$-cyclopentadienyl)(2,4-hexadienenitrile)cobalt [VII]. The compound [VII] was identified by NMR, mass spectrometer, IR and elemental analyzer etc.

기획특집 - 우리의 물 문제 어떻게 해결할 것인가?

이원식,Lee, Won-Sik 한국기술사회 2009 技術士 Vol.42 No.3

As Korea's water resources are dominated by intense summer rainfall and steep mountainous territory, it is inevitable for most of the rainfall in Korea to flow into sea immediately and directly. It cannot help having severe conditions which droughts and floods occur repeatedly due to the seasonal and geological conditions in Korea. Those kinds of disasters will be expected more frequently and seriously in the future because of the unexpected climate changes in the world. Therefore, Korean government will plan to develop small and medium-size dams environmentally friendly, multi-regional water supply system continuously and alternative water resources such as river bank filtrations, rainwater storages and underground dams, in order to prevent floods as well as to secure stable water supply.

가뭄과 홍수방지를 위한 수자원 개발 방향

이원식,Lee, Won-Sik 한국하천협회 2009 하천과 문화 Vol.5 No.2

자은도사를 (慈恩島砂) 이용한 N-Process 의 주형강도에 관한 연구

이원식 ( Won Sik Lee ) 한국주조공학회 1984 한국주조공학회지 Vol.4 No.2

The variations of the mold compression strength were studied by varing the contents of the silicon powder and water glass, silion purities, and molecule rates of the water glass, when domestic JA EUN DO sand is mixed with water glass (sodium silicate) and metallic silicon or ferro-silicon powder by the self-hardening N-PROCESS method. The results obtained from this experiment are as follows; 1) The compression strength of the mold used with metalic powder was higher and more stable than to be used ferro-silicon powder. 2) 6% water glass of 2.8 molecule rate and 1.5% of ferro-silicon of 75% purity for the N - PROCESS used with JA EUN DO sand was suitable mixing rate. 3) The compression strength increased with self-hardening time, and the PH values of the mixture of silicon powder and water glass did not change after 2 hours, but the compression strength increased steadily due to the reaction of remained silicon. 4) It is recommended to take 24 hours for self-hardening time at least.