• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.25.2-25.2
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• 2010

CNT(Carbon Nanotube)는 특이한 구조 및 뛰어난 물성을 갖고 있어, 여러가지 분야에 응용 가능한 신소재로서 연구되어 왔다. 또한 모양 및 구조에 따라 기계, 전기, 화학적인 특성이 달라 다양한 분야에서 활용이 가능하다. 외국에서는 FED tip, TR, 디스플레이 소자, 수소저장체, 고강도 복합체 및 대 표면적 전극 등 CNT의 다양한 특성을 이용한 응용이 연구되고 있는 반면, 국내에서는 이론연구와 합성연구에 편중되어 있다. 본 연구에서는 열 화학 기상법 (Thermal CVD)을 이용하여 MWNT(Multi-wall nano tube)를 성장시켜 촉매두께, 온도, gas변수에 따른 CNT의 양상을 분석하였다. Ni catalyst는 DC magnetron sputter를 이용하여 5~50nm 두께로 증착하였으며, 성장온도는 $800^{\circ}C$에서 $950^{\circ}C$까지 변화시켰다. 기판의 pre-treatment 로 ammonia($NH_3$) gas를 주입한 후, carbon precursor인 methane($CH_4$) gas와 $H_2$ dilute gas를 1:4의 비율로 주입하여 CNT를 성장시켰다. FE-SEM과 TEM, 그리고 XRD를 이용해 성장된 CNT의 형상 및 구조를 분석한 결과, 낮은 온도에서는 100nm이상의 두께를 갖는 수직형상의 MWNT가 성장되었으며, $900^{\circ}C$이상의 높은 온도에서는 20nm이하의 amorphous carbon nano rod가 성장되었다. 각각의 MWNT, carbon nano rod는 온도가 높을수록 직경이 증가하는 추세를 나타냈으며, Ni catalyst가 얇아질수록 수직형상을 갖는 결과가 나타났다. 또한 ammonia gas의 pre-treatment여부에 따라 CNT의 수직 형상이 좌우되는 결과를 확인하였다. 향후 성장된 MWNT의 최적 조건을 도출하여 디스플레이 소자인 FED(Field Emission Display)분야 등에 응용 가능할 것으로 전망된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.351-351
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• 2012

최근의 수 십 년 간, 실리콘 나노 와이어는 그 특수한 물성으로 인하여 큰 주목을 받아오고 있다. 또한, 나노 전자소자 개발에 있어 중요한 역할을 담당하며, 현재 실리콘은 반도체 산업 및 기술에서 핵심적인 기능을 수행하고 있기 때문에 실리콘 나노 와이어는 매우 중요하게 고려된다 [1]. 본 연구에서는 유도결합 수소 플라즈마와 PECVD를 이용한 ITO/glass위 실리콘 나노 와이어 형성을 실험하였다. 유도결합 수소 플라즈마를 이용하여 나노 사이즈의 인듐 catalyst를 형성한 후 PECVD를 이용 $SiH_4$ 가스 유량과 성장 온도를 변화시켜 그에 따른 형성 변화를 관찰하였다. Fig. 1 (a) 에서 보이는 바와 같이 $600^{\circ}C$, 30 sccm 5% $SiH_4$, 60 sccm He 조건에서 8분 동안 성장시켰을 경우와 Fig. 1 (b)의 100 sccm 5% $SiH_4$로 유량을 증가시키고 15분 동안 성장시킨 후 FE-SEM 사진을 비교 한 결과 실리콘 나노 와이어의 높이가 $31{\mu}m$로 크게 성장됨을 확인 하였다. 이는 $SiH_4$의 농도의 변화가 실리콘 나노 와이어 성장에 큰 영향을 미치고 있음을 나타내며 그에 따라 나노와이어의 높이를 조절할 수 있음을 보여주고 있다. 추가적으로 실리콘 나노 와이어 성장을 위한 인듐 catalyst 형성과 이를 이용한 ITO 기판위 실리콘 나노 와이어 성장에 따른 광학적 특성 및 XRD 분석 결과 또한 논의 하고자 한다.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.507-517
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• 2016

This study examines the types and characteristics of traumatic events middle-aged women experience and to explore the effects of attachment in the process of post-traumatic growth and forming a self-realization. 221 of participants were middle-aged women from the area of Seoul, Gyeong-Gi and the survey was composed of post-traumatic experience questionnaire, attachment scale, post-traumatic growth scale, self-realization scale. The type and characteristics of traumatic experience by middle-aged women were executed by frequency analysis and correlation with the structural equation model validation was used in order to analyze the relationship between each variable. the major findings are First, the loss of someone close(such as death, breaking up, divorce, breaking off) was reported as something general yet the biggest crisis event, Second, looking at the relationship between attachment, post-traumatic growth and self-realization, the secure parental attachment and spiritual transformation showed the correlation in all subregions except the subvariables of humanity and self-acceptance and Third, the results of Structural Equation Modeling shows that attachment has a static effect on post-traumatic growth and self-realization, and post-traumatic growth appeared to be the mediating factor of attachment and self-realization.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.6
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• pp.389-393
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• 2000

High-quality $Er^{3+}$ doped Mg : $LiNbO_3$single crystal fibers were grown by a micro-pulling down ($\mu$-PD) method. Single crystal fibers were pulled down through the nozzle, at a pulling down rate of 0.5 mm/min and using a Pt crucible with a nozzle 1 mm in diameter in air atmosphere. Defects such as bubbles, cracks and inclusions were not detected in any of the grown crystals. The optical transmission of Er : Mg : $LiNbO_3$crystal was measured and the energy levels of $Er_2O_3$ ion could be calculated. The photoluminescence spectrum of crystal fibers showed an energy band emission with the strongest line corresponding to the $^4I_{3/2}{\to}^4I_{15/2}$transition. The concentration dependence of the entire wavelength region emission intensity upon excitation intensity measured emission intensity for the 3 mol% MgO doped fibers was larger than that for the 1, 5 mol% MgO doped fibers.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.499-510
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• 2017

Based on "The Global Gender Gap Report" by World Economic Forum, this study identified factors of gender gap and analyzed a relationship between income growth and economic structural improvement with 145 countries. Consequently, sex ratio has a positive relationship with GNI growth rate and ICT development index. Female illiteracy has a negative relationship with only GNI growth rate, and female seat of parliament has a positive relationship with only with only GNI growth rate. Female labor participation rate has a positive relationship with inly ICT development index. These results confirmed the importance of future female labor force. With these results, many countries will need to reconsider discrimination against women and establish strategy based on an institution and a policy to prepare the 4th industrial revolution.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.147-157
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• 2019

In this study, we focused on the experience of interpersonal trauma among university students majoring in counseling psychology to understand the meaning of the trauma they experienced, and analyzed the process of their growth as counselors. To that end, we conducted a survey on interpersonal trauma and post-traumatic growth, and interviewed final six students in a face-to-face interview, and analyzed the collected data using the method of qualitative case study. As a result, the trauma and subsequent growth experience have been categorized into 38 semantic units, 15 subcategories and 5 categories, including 'Times of pain', 'A life of dealing with complex emotions alone', 'An experience of understanding and being understood', 'Attempts to change and new meanings' and 'Worries and expectations of growth as a counselor'. The results of this study are meaningful in providing basic information and educational materials needed for the intervention of students majoring in counseling psychology who have experienced trauma.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.213-220
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• 2022

This study was conducted to investigate the effect of environmental factors such as water temperature and rearing density on the survival and growth of Litopenaeus vannamei under low salinity conditions. Overall, in the higher water temperature, the higher survival rate comes out and in the lower rearing density, the higher the survival rate does. In a study on feed efficiency, weight gain (WG) increased significantly as water temperature increased, and weight gain according to rearing density significantly decreased as rearing density increased. The growth rate of L. vannamei was faster when the water temperature was higher (water temperature 31℃) under low salinity conditions. In addition, in the evaluation of the growth rate according to the rearing density, it was confirmed that the growth rate was accelerated at a low rearinging density. It is believed that the results of this study will be usefully applied to the determination of the optimal rearinging density and breeding water temperature of L. vannamei in low salinity condition.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.277-283
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• 2003

Purpose : Craniopharyngiomas are often accompanied by severe endocrine disorders. Although there is universal growth hormone deficiency(GHD), the resulting growth pattern is very heterogeneous. We report the growth and endocrine outcome of 44 children with craniopharyngioma, with emphasis on initial symptoms, growth before and during growth hormone(GH) treatment and spontaneous growth in spite of GHD. Methods : We performed a retrospective study of 44 children treated at our centre between 1984 and 2002. Results : About 30% of patients had symptoms suggesting endocrine disorder at diagnosis. After surgery, multiple endocrinopathies were almost universal. Before GH therapy, height velocity was $8.00{\pm}2.71cm/yr$ in the normal growth group(n=11) and $1.79{\pm}1.10cm/yr$ in the subnormal growth group(n=7) during the first year and during the second year, $6.76{\pm}2.49cm/yr$ and $2.29{\pm}1.33cm/yr$, respectively. There was no difference of body mass index(BMI) change between before and after surgery in the two groups. Height standard deviation score(SDS) was $-1.46{\pm}0.74$ in the normal growth group and $-0.43{\pm}0.97$ in the subnormal growth group. Before GH treatment height SDS was $-1.31{\pm}1.25$ and BMI was $20.46{\pm}3.60$. During GH treatment, height SDS increased to $-0.60{\pm}1.37$ in the first, and to $-0.41{\pm}1.54$ in the second year(P<0.05), but BMI did not change significantly. Conclusion : The endocrine morbidity could develop in most children with craniopharyngioma before and after the operation and should be managed properly. Although all treated patients benefit from GH therapy, further studies are necessary to find out the possible mechanism of growth regulation in normally growing children, despite GH deficient.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1690-1700
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• 2013

The objective of this study is to develop and validate predictive growth models for Bacillus cereus (diarrhea type) vegetative cells, spores and Staphylococcus aureus in preprocessed Namul (bracken and Chwinamul) and root vegetables (bellflower and burdock). For validation of model performance, growth data for S. aureus in preprocessed vegetables were collected at independent temperatures (18 and $30^{\circ}C$) not used in the model development. In addition, model performance of B. cereus (diarrhea type) in preprocessed vegetables was validated with an emetic type of B. cereus strain. In primary models, the specific growth rate (SGR) of the B. cereus spores was faster than that of the B. cereus vegetative cells, regardless of the kinds of vegetables at 24 and $35^{\circ}C$, while lag time (LT) of the B. cereus spores was longer than that of the B. cereus vegetative cells, except for burdock. The growth of B. cereus and S. aureus was not observed in bracken at temperatures lower than 13 and $8^{\circ}C$, respectively. The LT models for B. cereus (diarrhea type) in this study were suitable in predicting the growth of B. cereus (emetic type) on burdock and Chwinamul. On the other hand, SGR models for B. cereus (diarrhea type) were suitable for predicting the growth of B. cereus (emetic type) on all preprocessed vegetables. The developed models can be used to predict the risk of B. cereus and S. aureus in preprocessed Namul and root vegetables at the retail markets.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.47-50
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• 1997

희토류원소의 광 환원 침전 특성이 연구되었다. 환원제로 isopropyl alcohol, 침전제로 (NH$_4$)$_2$SO$_4$가 사용되었다. 그리고 250nm의 파장을 방출하는 수은 램프가 사용되었다. Eu원소만을 함유하는 용액으로부터 Eu+3의 Eu+2로의 광 환원 결과는 97%이상이었으며 과산화수소가 소량 첨가되었을 경우 침전 속도는 증가하였다. 이 결과를 토대로 하여 희토류원소들(Sm,Eu,Gd)을 함유하는 수용액과 유기용액(HDEPH-Dodecan)에 UV광을 조사하였을 시 선택적으로 Eu을 분리해 낼 수 있었다. Eu의 침전 회수율은 두 상의 경우 모두 97%이상이었다.