• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.410-410
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• 2010

한TFT-LCD, Solar cell, 반도체 등에 사용되는 Si 박막은 주로 PECVD로 형성한다. 이 때 사용되는 원료 가스로 $SiH_4$가 있으며 대개 $H_2$로 희석해서 사용한다. 저온 증착의 경우 전자 충돌 해리과정을 이용하여 증착이 이루어지며 이 때 중간 생성물로 $SiH_3$, $SiH_2$와 고차유도체($Si_xH_y$)가 생성된다. 고밀도 플라즈마를 이용하는 경우에는 이들의 이온(양, 음)의 비율도 막질 형성에 중요한 요소가 된다. 본 발표에서는 안테나가 외부 및 내부에 있는 경우에 대해서 모델링하였으며 해리된 유도체의 비율은 $SiH_3$ > $SiH_2$의 순서였고 가스 조성비(수소 희석비), U-type 내장형 안테나와 기판 사이의 거리, 챔버 내의 펌핑 포트의 위치 등에 의한 차이가 플라즈마 온도 및 밀도의 균일도에 미치는 영향을 분석하였다. 수치 모델상의 가장 중요한 변수의 하나인 이온, 라디칼의 표면 재결합 상수는 문헌에서 보고된 값을 구하기 어려운 경우에는 가장 실제와 근접한 경향이 나타나는 값을 사용하였다. 이 부분은 분자 동력학 등의 기법을 이용하여 보다 상세한 데이터를 만들어 낼 수 있는 방법의 적용이 필요하다. 기본적인 $SiH_4$의 화학 반응식은 이원기[1]등의 데이터를 이용하였다. 계산 결과 중의 특이한 점의 하나는 고차 유도체인 $Si_2H_4$의 경우 중성보다 오히려 양이온의 밀도가 1 order이상 높았다. 내장형 Y-type 안테나의 경우 전력 흡수 밀도가 $10^7\;W/m^3$ 수준으로 높은 영역이 안테나 주변으로 나타났으며 안테나와 기판 사이의 거리와 압력에 따라서 기판에서의 균일도가 결정 되었다.

• Korean Journal of Plant Taxonomy
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• v.32 no.3
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• pp.293-299
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• 2002

A new taxon of Ilex is described from Wando Island, Province Jeonnam, Korea. Ilex x wandoensis C. F. Miller & M. Kim hybrid nov. originates from the natural hybridization of the parent species, I. cornuta Thunb. and I. integra Thunb. Leaves of the new taxon have smooth, spinose margins, a condition that is intermediate between the twisted, spinose leaf margins of I. cornuta and the smooth, entire margins of I. integra. The new hybrid species shares several characters with its two parents, including evergreen leaves, dioecy, and red drupes.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.393-394
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• 2019

본 연구는 현재 임신 중인 임산부 중 6개월 이상의 임산부를 대상으로 스스로가 본인의 체형을 어떻게 인식하고 있는가 하는 주관적 평가를 유형화하고 유형별 특성을 고찰하고자 하였다. 이를 통해 임산부의 체형에 적합한 의복디자인 및 패턴설계에 필요한 기초자료를 제공하고자 하였다. 본 연구는 Q방법론을 사용하였으며, Q분석은 쿼넬 프로그램(QuANL pc program)을 사용하였다. 임산부의 체형에 대한 인식 유형은 가는 팔다리 중앙 반구형 복부 체형, 처진 복부 돌출 체형, 굵은 윗팔 중앙 돌출 복부 체형의 3가지 유형으로 분석되었다. 가는 팔다리 중앙반구형 복부 체형은 임신 전 BMI지수가 가장 낮아 정상에 속하였으며 팔다리는 가늘고 다른 부위는 거의 살이 찌지 않았으며 배만 나왔다고 인식하였다. 처진 복부 돌출 체형은 임신 전 BMI 지수가 가장 높아 과체중에 속한 유형으로 가슴둘레, 엉덩이둘레뿐만 아니라 몸에 전체적으로 살이 쪘으며, 배가 아래로 처진 체형으로 인식되었다. 굵은 윗팔 중앙 돌출 복부 체형은 제1유형과 같이 복부의 중앙부분이 돌출되어 있다고 인식하였으나 윗팔둘레가 굵어졌다고 인식하여 제1유형과는 차이를 나타냈다. 임신 전 BMI 지수는 중간인 그룹으로 정상에 속하였다. 향후 연구에서는 임산부의 실제 체형 분석을 통하여 본 연구의 인식체형과의 차이를 비교 분석해보는 것도 의미 있는 연구가 될 것으로 생각된다.

• Clinical and Experimental Pediatrics
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• v.50 no.2
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• pp.190-197
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• 2007

Purpose : Reduced growth and microvascular complications have been recognized as consequences of type 1 diabetes mellitus (T1DM). We assessed the effect of T1DM on growth and factors associated with the development of microvascular complications. Methods : We conducted a retrospective longitudinal evaluation of 154 patients above 16 years of age. We analyzed factors which affect final height standard deviation scores (SDS) and development of microvascular complications. Results : Final height SDS was $-0.11{\pm}1.15$ ($-0.26{\pm}1.33$ in females, $0.04{\pm}0.91$ in males). Final height SDS was significantly lower than midparental height SDS and height SDS at diagnosis. There was no difference in final height SDS according to age at onset, existence or nonexistence of complications, or average $HbA_{1C}$. Height SDS at onset of puberty, midparental height SDS and pubertal growth gain affected final height SDS. The number of patients with complications was 37 (24 percent). Microvascular complications developed at a younger age and after longer duration of diabetes in patients with a prepubertal onset of T1DM compared to patients with pubertal onset. Patients with complications had a higher level of average $HbA_{1C}$ than patients without complications. Patients whose microalbuminuria regressed had lower levels of average $HbA_{1C}$, systolic BP, second 24h urine microalbumin than patients with persistant or progressed microalbuminuria. Conclusion : The results suggest that degrees of glycemic control don't affect final height, but various factors associated with T1DM can impair growth potential. Additionally, the degrees of glycemic control and puberty affect the development of microvascular complications.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.105-114
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• 2016

When impact load is applied to a plate structure, a common phenomenon that occurs in structures is plastic deformation accompanied by a large strain and eventually it will experience a fracture accordingly. In this study, for the rational design against accidental limit state, the plastic material constants of steel plate which is formed by line heating and by cold bending procedure have been defined through the numerical simulation for the high speed tension test. The usefulness of the material constants included in Cowper-Symonds model and Johnson-Cook model with the assumption that strain rate can be neglected when strain rate is less than the intermediate speed is verified through comparing the present numerical results with those in references. This paper ends with describing the future study.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.174-183
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• 2018

In the Sumeunmulbaengdui Wetland Protected Area of Jeju Island, there exists a unique pond, a so-called 'Ohmi', which is likely to be an oasis supporting the wildlife and escaped-livestock. We exquisitely described the diversity and distribution of plant community of the Ohmi. Despite its small area, six syntaxa were identified: Sphagnum community of peat bog type, Nymphoides coreana community of the floating-leaf limnetic vegetation, Scirpus triangulatus community and Schoenoplectus hotarui community of the littoral zone vegetation, and Deinostema violacea-Eleocharis congesta community and Eriocaulon atrum-miquelianum community of the ephemeral vegetation. A zonal distribution of plant communities along the water depth was recognized. The Sphagnum islets regarded as a typical component of peat bog, in Korea were first described at the center of the Ohmi. We conclude that the Ohmi is a primeval keystone habitat of the Sumeunmulbaengdui intermediate moor with a less oligotrophic ombrotrophic environment.

• Animal Systematics, Evolution and Diversity
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• v.12 no.3
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• pp.203-210
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• 1996

Four external and 27 cranial characters of Korean field mice (Apodemus peninsulae) from nine regions in China and Korea, representing three subspecies, were analyzed by multivariate methods. Four size-forms were recognized a largest-size form Mt. Weolak and Yeoncheon in Korea (= subspecies peninsulae) and Kirin and Heilung in China (= subspecies praetor), a large-size form from Inner Mongolia in China (= subspecies praetor) and Sanxi and Sandong in China (= subspecies sowerbyi), a middle-size form from Beijing in China (= subspecies sowerbyi), and a small-size form from Xinjiang in China (= subspecies sowerbyi). Although Corbet (1978) recognized only two subspecies in A. peninsulae, subspecies peninsulae and sowerbyi, within its distributional range in the continent of Asia, it was revealed in this study with morphometric characters that A. peninsulae could not be classified simply into two subspecies, because subspecies praetor and subspecies sowerbyi formed the large-size form and because subspecies sowerbyi was so diverse in its morphology as to be composed of three size-forms. Further analyses with the samples from other regions of China and Russia seem to be necessary to clarify the taxonomy of A. peninsulae.

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.191-205
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• 2017

We use small-scale modelling to estimate the impact ofrce of debris flows on erosion control dams (ECD) and ring nets. The results indicate that the viscoelastic debris flows produced impact forces of 4.14, 3.66, 1.66 kN from the bottom to the top of the ECD. Ring net tests produced a similar trend with generally smaller impact forces (2.28, 1.95, and 1.49 kN). Numerical analysis showed that the weight of the ECD (e.g., concrete retaining walls) provided resistance against the debris flow, whereas deformation of the ring net by elastic-elongation and aggregate penetration reduced the impact force by up to 45% compared with that of the ECD.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.1-7
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• 2017

In this paper, a design method for a compact stepped open slot antenna for an operation in the UWB band is studied. The proposed antenna is miniaturized by inserting L-shaped slots on the ground plane of the stepped open slot antenna through the creation of a resonance in the low frequency, and a strip director is appended to the antenna in order to increase the gain in the middle and high frequency regions. The effects of varying the length of the L-shaped slots, the distance between the director and the slot antenna, and the director length on input reflection coefficient and realized gain characteristics of the proposed antenna are analyzed. The optimized antenna with the size of $30mm{\times}30mm$ is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 3.02-11.04 GHz for a VSWR < 2, which assures the operation in the UWB band.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.23-27
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• 2015

The stress and deformation behavior safeties of cylindrical hollow rollers have been analyzed by the finite element method, and investigated for over design capability based on the computed results. According to the stress analysis result which is related to the strength of a hollow roller, the maximum stress of 39.8MPa in which is operated near the bearing for supporting a hollow roller structure is overestimated design as 15.9% level compared with a yield strength, 250MPa of a steel material. And the maximum deformation of 0.032mm in which is operated at the middle span of a total length of cylindrical hollow rollers is very small and sufficiently safe compared with a total length and a thickness of a hollow roller. Thus, the FEM computed results for a stress and deformation indicate that a current FEM analysis model of cylindrical hollow rollers is over designed.