Correlation between Coil Configurations and Discharge Characteristics of a Magnetized Inductively Coupled Plasma

Hee-Woon Cheong 한국자기학회 2016 Journal of Magnetics Vol.21 No.2

Correlation between coil configurations and the discharge characteristics such as plasma density and the electron temperature in a newly designed magnetized inductively coupled plasma (M-ICP) etcher were investigated. Radial and axial magnetic flux density distributions as well as the magnetic flux density on the center of the substrate holder were controllable by placing multiple circular coils around the etcher. The plasma density increased up to 60.7% by arranging coils (or optimizing magnetic flux density distributions inside the etcher) properly although the magnetic flux density on the center of the substrate holder was fixed at 7 Gauss.

Magnetic Flux Density Distributions and Discharge Characteristics of a Newly Designed Magnetized Inductively Coupled Plasma

Hee-Woon Cheong 한국자기학회 2015 Journal of Magnetics Vol.20 No.4

Spatial distributions of magnetic flux density in a newly designed magnetized inductively coupled plasma (MICP) etcher were investigated. Radial and axial magnetic flux densities as well as the magnetic flux density on the center of the substrate holder were controllable by placing multiple circular coils around the etcher properly. The plasma density non-uniformity in M-ICP (25 Gauss) can be reduced (1.4%) compared to that in ICP (16.7%) when the neutral gas pressure was 0.67 Pa and a right-hand circularly polarized wave (R-wave) can be propagated in to the etcher by making magnetic flux density increases both radially and axially from the center of the substrate holder.

Newly Designed Ion Beam Etcher with High Etch Rate

Hee-Woon Cheong 한국자기학회 2015 Journal of Magnetics Vol.20 No.4

New ion beam etcher (IBE) using a magnetized inductively coupled plasma (M-ICP) has been developed. The magnetic flux density distributions inside the upper chamber, where the plasma is generated by inductive coupling, were successfully optimized by arranging a pair of circular coils very carefully. More importantly, the proposed M-ICP IBE exhibits higher etch rate than ICP.

A New Peanut Cultivar, Daemyung with Large Seed, High Yielding and Wide Adaptability

Young Keun Cheong,Chang Whan Park,Ki Hun Park,Hee Woon Park,Hong Soo Doo,Moon Hee Lee,Seong Hee Lee 한국육종학회 2004 한국육종학회지 Vol.36 No.5

A new peanut variety “Daemyung(Arachis hypogaea L.)” was developed from the cross between SP8703-2-2 and SP8708-4-1 at the Honam Agricultural Research Institute, National Institute of Crop Sciencee in 2003. This variety belongs to shinpung type with erect

Platform for wireless pressure sensing with built-in battery and instant visualization

Cheong, Woon Hyung,Oh, Byungkook,Kim, Se-Hee,Jang, Jiuk,Ji, Sangyoon,Lee, Seunghee,Cheon, Jinwoo,Yoo, Seunghyup,Lee, Sang-Young,Park, Jang-Ung Elsevier 2019 Nano energy Vol.62 No.-

<P><B>Abstract</B></P> <P>Wireless communication through linkage with a smartphone and other portable devices in the sensor area are essential for increasing the efficiency of utilization by storing sensing-value data. Thus, the demand for wireless technology is increasing due to the advantages it provides for the various applications that use these data. However, there is still considerable ambiguity concerning the low portability of such technology due to the increased volume with component integration, the high consumption of power, and the necessity of having a separate battery. Herein, we present solutions for these problems with demonstrations that involve 1) the miniaturization of the device by altering the structure of the built-in battery, 2) the use of a pressure-activated switch for the low-power driving technology, and 3) the implementation of a wireless communication platform by integrating a Bluetooth module with the devices. In addition, we demonstrate a human-interactive display that enables users to instantly observe the changes in the brightness of the organic light-emitting diodes (OLED) as the pressure changes. We show that the system can display the measured, real-time pressure values on the screens of mobile devices, which represents a significant advancement in the fields of energy science and biomedical science.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Integrated system of portable pressure measuring device is developed. </LI> <LI> The built-in structure of the battery present high portability and the switch enables long-term operation. </LI> <LI> The device is capable of wireless communication with smartphones in real-time. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

국민학교 학생들의 과학에 관련된 태도 조사 연구

임청환,최재환,손석락,송남희,송명섭,이운환,김중욱 한국초등과학교육학회 1995 초등과학교육 Vol.14 No.1

The purpose of this study is to investigate the attitudes related to the science of elementary school students. To investigate the attitude, modified TOSRA and KEDI's attitude instrument used for measuring attitudes which was developed by Korea National University of Education. 710 subjects was sampled by stratified cluster sampling method. The major findings of this study are as follows. 1. Fifth grade students have significantly higher attitude scores than other grade students. 2. The value of correlation coefficient among subcategories of science attitudes was 0.3773∼0.6336, which was significant at the 0.001 level. 3. There was statistically significant difference between grade and sex in elementary school students.

냉동치즈볼의 미생물학적 안전성 확보를 위한 감마선 조사기술의 이용

이주운(Ju-Woon Lee),김재훈(Jae-Hun Kim),김장호(Jang-Ho Kim),오상희(Sang-Hee Oh),서지현(Ji-Hyun Seo),김천제(Cheon-Jei Kim),정승희(Sung-Hee Cheong),변명우(Myung-Woo Byun) 한국식품영양과학회 2005 한국식품영양과학회지 Vol.34 No.5

본 연구는 감마선 조사기술을 이용한 치즈볼의 위생화를 목적으로 실시하였다. 감마선 비조사구의 총균수는 4.4 log CFU/g 정도이었으나, 감마선 조사선량이 증가할수록 미생물수가 유의적으로 감소하여 3 kGy 이상의 감마선 조사구에서는 미생물 검출을 위한 최소한계치인 100 CFU/g 이하이었고, D_(10) 값은 0.83 kGy로 나타났다. 또한, 효모 및 곰팡이는 감마선 비조사 대조구의 경우 2.8 log CFU/g 수준이었으나, 0.5 kGy 이상의 감마선 조사에 의해 모두 미생물 검출 한계치 이하로 나타났다. 한편, 치즈볼에 E. coli(KCTC 1682)를 접종한 후의 D10 값은 0.25 kGy로 나타났다. 감마선 조사직 후 지방산패도는 3 kGy 이하에서는 비조사구와 비교할 때 유의적 차가 없었으나, 5 kGy 이상에서는 감마선 조사선량이 증가할수록 유의적으로 증가하였다. 또한, 관능평가결과는 지방산패도 결과와 마찬가지로 3 kGy 이하의 선량에서는 대조구와 비교할 때 유의적 변화가 없는 것으로 나타났으나, 5 kGy 이상의 선량에서는 방사선 조사선량이 증가할수록 향, 맛, 종합적 기호도의 점수가 낮아지는 것으로 나타났다. 이상의 결과를 종합하여 볼 때 치즈볼의 관능적 품질변화를 최소화하고 미생물학적 저장안전성을 확보하기 위한 최적 방사선 조사선량은 3 kGy인 것으로 사료된다. This study was conducted to sanitize fried-frozen cheese ball by gamma irradiation. Total aerobic bacteria and yeasts and molds counts were 4.4 and 2.8 log CFU/g in non-irradiated sample, respectively. Microorganisms were decreased with increase of irradiation dose (D_(10)=1.25 kGy), and were not detected in samples irradiated at 3 kGy or more (<10² CFU/g). D_(10) value for Escherichia coli (KCTC 1682) was 0.25 kGy. TBA (2-thiobarbituric acid) values were increased as irradiation dose was increased, but there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less (p<0.05). The results of sensory evaluation showed that there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less, the sensory scores were decreased with irradiation at 5 kGy or more (p<0.05). These results indicated that gamma irradiation at 3 kGy was considered to be an effective treatment to ensure the micro- biological safety of fried-frozen cheese balls without any sensorial change, even though further studies should be investigated to reduce detrimental effects induced by irradiation.

경추 정면 검사에서 방사선 입사각에 관한 연구

정성운(Seung-Woon Jeung),임청환(Cheong-Hwan Lim),한범희(Beom-Hee Han),정홍량(Hong-Ryang Jung),주영철(Yeong-Cheol Joo),박미자(Mi-Ja Park) 대한방사선과학회(구 대한방사선기술학회) 2012 방사선기술과학 Vol.35 No.2

경추 정면 방사선검사 시 하악골, 후두골의 겹침 방지, 경추 추체의 배열 및 관절의 형태 등을 관찰하기 위하여 X선 입사각을 머리 방향으로 15~20°를 주고 있는 것이 보편적이다. 하지만 한국인의 체형에 맞는 입사각에 대한 연구는 거의 이루어지지 않고 있다. 이에 본 연구에서는 한국인에 적합한 입사각을 찾고, 방법을 제시하는데 목적이 있다. 입사각을 측정하기 위하여 서산에 위치한 S병원을 내원한 환자 1,044명을 대상으로 하였으며, 제 2번 ~ 제 5번 경추의 길이, 피사체-영상판 거리(OID), 제2번 경추(axis)의 경사도, 초점 - 영상판 간거리(FID)를 측정하였으며, 연령대 성별에 대한 평균값을 측정하여 적용공식에 의하여 입사각을 산출하였다. 경추 제 2번~제 5번의 평균길이는 6 ㎝ 이였으며, 10대부터 20대 까지는 경추의 길이가 커지고 30대 이후로는 경추의 길이가 작아졌으며, 남성과 여성의 차이는 약 1 ㎝ 차이가 나타났다(p<.001). OFD는 연령대, 성별과 상관없이 거의 같은 값이 측정이 되었다. 제2번 경추(axis)의 경사도는 10대와 20대는 경사도가 증가하였지만, 30대 이후로는 작게 나타났다. 또한 남성과 여성은 약 2°차이가 났다. (p<.001). FID의 측정 결과, 연령대, 성별과 상관없이 거의 같은 값이 측정되었으며, 이 값 으로 입사각을 측정한 결과, 10대는 15.9°, 20대 16.9°, 30대 16.6°, 40대 16.2°, 50대 15.9°, 60대 14.5°로 측정 되었다. 10대와 20대까지 입사각이 증가하였지만, 30대 부터는 입사각이 작게 나타났다. 또한 10대는 남 성과 여성이 같은 값으로 측정이 되었고, 20대 부터는 남성과 여성이 2°차이가 나타났다. 입사각과 제 2번~ 제 5번 경추의 길이측정, OID, 제2번 경추의 경사도, FID 와의 상관관계를 실시하였고, 입사각과 모두 유의한 상관관계가 나타났다(p<.001). 본 연구에서 경추의 평균 길이, OID, FID, 제2번 경추 (axis)의 경사도에 따라서 입사각이 다르게 나타났고, 성별과 연령에 따라 입사각이 다른 것을 알 수 있었다. 그러므로 경추 정면검사 시 연령, 성별을 고려하여 입사각을 설정하면서 검사를 시행하여야 함이 사료되며, 향후 경추검사의 입사각을 설정할 때 참고 자료로 이용될 것으로 기대된다. In anteroposterior projection for cervical vertebra, it is general that the incidence angle of X-ray is 15° to 20° degrees to head in order to prevent overlap of mandible and occipital bone and to observe array of cervical interbody and shapes of joints. However, the angle is appropriate for foreigners that was determined by foreign literature review long ago, and there have been few researches of incidence angle for Koreans’ body type. The purpose of in this study are to identify the incidence angle appropriate for Koreans and to present methodology. In order to measure the incidence angle, 1,044 patients who visited S Hospital located in Seosan were selected and measured of average length of cervical vertebra, OID, axis angle, and FID. The incidence angle was calculated from the applied formula by measuring average values per age groups and sex (see Formula 1 and 2). The average length of cervical vertebra was 6cm: the length was increased from teenagers to twenties but was decreased since thirties. The difference between males and females was around 1cm (p<.01). The OID was almost the same regardless of age groups and sex. As for axis angle, the slope was increased in teenagers and twenties, but was decreased since thirties. The difference between males and females was around 2 degrees (p<.01). The FID measurements were almost the same regardless of age groups and sex, and when the incidence angle was measured from these values, the teenagers were 15.9°, the twenties were 16.9°, the thirties were 16.6°, the forties were 16.2°, the fifties were 15.9°, and the sixties were 14.5°, indicating that the angle was increased from teenagers to the twenties but decreased since the thirties. While the angles of males and females were measured to be the same in the teenagers, the angle was different between males and females by 2°. When the incidence angle statistically analyzed with measurement of average length of cervical vertebra, OID, axis angle, and FID, all of them were shown to have correlations with the incidence angle (p<.01). Conclusively, it was shown that the incidence angle was measured differently from average length of cervical vertebra, OID, FID, and axis slope, as well as from age and sex. Therefore, it can be suggested that the anteroposterior radiation test for cervical vertebra should be conducted by different incidence angles based on age and sex. The data of this study may be used as reference in determining the incidence angle of cervical vertebra tests for the future.

Design of highly efficient RGB top-emitting organic light-emitting diodes using finite element method simulations

Park, Woo-Young,Cheong, Hee-Woon,Lee, Changhee,Whang, Ki-Woong The Optical Society 2016 Optics express Vol.24 No.21

초음파를 이용한 장중첩증의 진단 및 식염수 정복

김재훈,정수진,한창희,장해운,김기호,손세호,방찬영 최신의학사 1993 最新醫學 Vol.36 No.9