열수렴파 측정법을 이용한 다이아몬드 웨이퍼의 열전도율 특성에 관한 연구

주영철 순천향대학교 부설 산업기술연구소 2000 순천향 산업기술연구소논문집 Vol.6 No.1

A converging thermal wave technique is developed to measure the thermal conductivity of a diamond wafer. A FDM program and an analytic solution are developed to analyze the measurement data. It has been shown that these two method agrees quite well. This method provides an accurate and convinent method to measure the thermal conductivity of a thin material such as a diamond wafe.

1999년에 발생한 기상재해 유형별 벼 수량반응조사 연구

주영철,임갑준,한상욱,박중수,조영철,김순재 한국농림기상학회 2000 한국농림기상학회지 Vol.2 No.1

The objectives of this study were to investigate weather conditions which induced discolored grains and viviparous germination, and to evaluate yield responses following viviparous germination during mid- and late- ripening stage, the submergence during reproductive growth stage, and lodging in the yellow ripe stage. Weather conditions which caused glume discoloration at heading stage were 21.3-26.4℃ in average temperature, 75.2-98.4% in relative humidity, 19.3 in transpiration coefficient and 10.8-13.8 m/sec. in wind speed. Yield reduction was 26-27% and 10∼17%, respectively, when the glume discoloration rates were 63.2-65.7% and 38.3-45.2%, obviously due to the decrease in percent of fertile grain and ripening ratio. Weather conditions during continuous rain for 7 days were 96% in relative humidity, 18.9℃ in average temperature, 21.9℃ in maximum temperature, and 16.8℃ in minimum temperature, causing the most viviparous germination in Juanbyeo(45.5%), followed by Jinbubyeo(14.5%), Bongkwangbyeo(14.2%), and Obongbyeo(12.6%). Lateral tillers started to occur when the submergence at the depth of 1.5-2 m lasted one day during the reproductive growth stage. The submergence for 2-3 days at 3-4 m of water depth induced 269-571 lateral tillers/㎡, supporting 32-52% of the total yield. The rice yield in the paddy fields which were left under the lodging conditions until harvesting was not different compared to that of the paddy fields which were kept upright by tieing them together after lodging, but perfect grain ratio decreased about 9.1% in the transplanting culture and 12.5% in the direct seeding culture on dry paddy field because of the increase in immature grains.

핵연료 소결체 내부에서의 열적특성에 관한 수치적 해석

주영철,박권현 대한기계학회 1986 대한기계학회 춘추학술대회 Vol.- No.-

주얼리용 마스터패턴의 쾌속제작에 관한 연구

주영철,이창훈,송오성 한국산학기술학회 2002 한국산학기술학회논문지 Vol.3 No.2

주얼리 제조 공정중 마스터패턴 제조 공정은 전체 제조원가의 20%를 차지하기 때문에 매우 중요한 공정이다. 지금까지는 수작업으로 왁스 패턴을 제작하고 이를 이용하여 석고형을 만들고 석고형로 마스터 패턴을 제작하는 복잡한 공정을 거쳐 제작하였다. 본 연구는 쾌속조형기를 이용하여 듀라폼 재질의 몰드를 만들고 저융점합금을 이용하여 마스터패턴을 직접 제작하는 새로운 공정을 개발하였다. 듀라폼의 용융점이 190℃ 이므로 용융점 70℃의 Pb-Sn-Bi-Cd 제의 저융점 합금을 주물재료로 이용하여 마스터패턴을 제작하였다. The master pattern manufacturing process is one of the most important processes in jewelry industry because the process takes 20% of total jewelry manufacturing costs. The previous jewelry manufacturing process has many steps of "rough design → detailed drawing → wax pattern manufacturing → lime soda flask mold manufacturing → silver master pattern manufacturing → mass production of wax pattern → investment casting process → final jewelry product." A novel process that reduces processing steps by using a rapid prototyping system (RP) has been suggested. The process is "3D CAD design → DuraForm mold manufacturing by RP → manufacturing master pattern by low melting alloy → mass production of wax pattern → investment casting process → final jewelry product." Molds are made with DuraForm powder, of which melting temperature is 190℃, by a selective laster sintering type RP. An alloy of Pb-Sn-Bi-Cd, of which melting temperature is 70℃, is casted in the DuraForm molds. Spheres and rings of diameter 20 ㎜ are made by this process. The dimension deformation rate is less than 2%, and the post processing of the castings is convenient. The casting made by the suggested process can be used as a master pattern of jewelry products.

견 관절 Arch view에 대한 고찰

주영철,안창룡,김동환,문희석,조남수 대한방사선사협회 2002 대한방사선사협회지 Vol.28 No.1

자궁경관의 양성 병변에 대한 냉동치료 법의 임상적 효과

주영철,유석권,엄승호,강대웅 대한산부인과학회 1980 Obstetrics & Gynecology Science Vol.23 No.5

자동노출제어장치 유·무에 따른 흉부 후·전방향 검사 시 관전압 변화에 따른 선량 및 영상평가

주영철,홍동희 한국방사선학회 2022 한국방사선학회 논문지 Vol.16 No.7

This study was conducted to improve the problems of exposure dose and image reading applied to patients due to the incorrect use of AEC during chest radiography. Images were acquired by dividing the case where AEC was used as the test condition and the case where AEC was not used. As a result of the study, the dose was reduced by 1.17% in 110 kVp without AEC than with AEC, 17.2% decrease at 100 kVp, 30.19% decrease at 90 kVp, and 46.45% decrease at 80 kVp. There was a significant difference in the statistical values ​​according to the tube voltage change in the lung, trachea, and heart SNR average values ​​with AEC and without AEC 110 kVp, but the difference in image quality was insignificant in actual images. When AEC was not applied at the same tube voltage, the dose could be reduced by 17.2% while maintaining the image quality similar to that of with AEC at 100 kVp without AEC. Therefore, rather than relying on AE conditions during chest radiographic examination, it is considered that the conditions should be considered for the examination while lowering the dose by selecting an appropriate tube voltage. 본 연구는 흉부 방사선검사 시 AEC의 잘못된 사용으로 환자에게 가해지는 피폭선량 및 영상판독의 문제점을 개선하고자 연구를 진행하였다. 검사조건으로 AEC를 이용한 경우와 AEC를 사용하지 않은 경우로 구분하여 영상을 획득 하였으며 0.6 mAs를 고정시키고 110, 100, 90, 80 kVp의 조건으로 촬영하였다. 연구 결과 without AEC 110 kVp가 with AEC보다 선량은 1.17% 감소하였고 100 kVp에서는 17.2% 감소, 90 kVp에서는 30.19% 감소, 80 kVp에서는 46.45% 감소하였다. 폐와 기관, 심장에서 SNR의 평균값의 차이는 with AEC와 without AEC 110 kVp에서 관전압 변화에 따른 통계적인 수치에서는 유의한 차이가 있었으나 실제 영상에서 화질의 차이는 미비하였다. 동일한 관전압에서 AEC를 적용하지 않은 경우 특히 without AEC 100 kVp에서는 with AEC와 유사한 화질을 유지하면서 선량을 17.2% 감소시킬 수 있었다. 그러므로 흉부 방사선 검사 시 AEC 조건에 의존하기보다 적절한 관전압 선택으로 선량을 낮추면서 검사하는데 조건을 고려해 보아야 할 것으로 사료된다.

기관탐방 : 경기도농업기술원 버섯연구소를 찾아서

주영철 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2007 식품저장과 가공산업 Vol.6 No.1

OLED 증착용 서큘러소스의 열적성능 해석

주영철,한충환,엄태준,이상욱,김국원,Joo, Young-Cheol,Han, Choong-Hwan,Um, Tai-Joon,Lee, Sang-Wook,Kim, Kug-Weon 한국반도체디스플레이기술학회 2007 반도체디스플레이기술학회지 Vol.6 No.4

Temperature distribution of the circular heat source was studied by analyzing the heat transfer of the environment of the circular source for OLED. Circular nozzle source was used to fabricate thin organic layer as the organic material in it was heated, vaporized and deposited to the large size panel. A modified heater structure of circular source has been suggested. The results of numerical analysis shows that the modified heater structure can use 15% more powder in a batch than the original heater structure does. Moreover, the modified heater structure can improve the uniformity of organic vapor deposition by controlling the temperature.

MEMS 공정으로 제작한 NO₂ 마이크로 가스센서의 열전달 해석

주영철,이창훈,김창교 한국산학기술학회 2004 한국산학기술학회논문지 Vol.5 No.2

대기중의 NO₂ 가스 농도를 측정하기 위한 마이크로 가스센서를 MEMS 공정을 이용하여 제작하였다. WO₃와 같은 가스 감응물질을 목표 온도까지 가열하기 위해서 마이크로 핫플레이트를 가스센서에 장착하였다. 마이크로 가스센서의 열전 달 현상을 상용 열유동 해석 전용 프로그램인 FLUENT를 이용하여 해석하였다. 해석 결과 실리콘 웨이퍼 기판의 온도가 거의 상온에 가까워 핫플레이트에서 발생한 열이 가스 감응물질을 효과적으로 가열하여서 가스감응물질의 열적 고립상태를 유지하고 있는 것을 알 수 있었다. 마이크로 핫플레이트의 형상을 변경함으로써 가스 감지물질의 온도 균일도를 높일 수 있다. A flat type NO₂ micro gas sensor was fabricated by MEMS technology. In order to heat up gas sensing material such as WO₃ to a target temperature, a micro hotplate was built on the gas sensor. The temperature distribution of micro gas sensor was analyzed by a CFD program, FLUENT. The results showed that the temperature of silicon wafer base was almost similar to that of the room temperature, which indicates that the heat generated at the micro hotplate heated up effectively the sensing material and its thermal isolation was kept. The uniformity of temperature on the sensing material can be improved by modifying the shape of micro hotplate.