• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.628-631
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• 2004

A tetrafluoromethane$(CF_4)$ is most useful gas in plasma dry etching, because it has a electron attachment cross-section. therefor it is important to calculate transport coefficients like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient. and critical E/N. The aim of this study is to get these transport coefficients for information of the insulation strength and efficiency of etching process. Electron transport coefficients in $CF_4+Ar$ gas mixture are simulated in range of E/N values from 1 to 250 [Td] at 300[K} and 1 [Torr] by using Boltzmann equation method. The results of this method can be important data to present characteristic of gas for plasma etching and insulation, specially critical E/N is a data to evaluate insulation strength of a gas. and is presented in this paper for various mixture ratios of $CF_4+Ar$ gas mixture.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.44-47
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• 2009

This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. $SF_6$ gas is widely used in industrial of insulation field. In this paper, $N_2$ is mixed to improve pure $SF_6$ gas characteristics. Electron transport coefficients in $SF_6-N_2$ mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method. which are ionization coefficient, attachment coefficient, effective ionization coefficient, and critical E/N, can be important data to present characteristic of gas for insulation. Specially critical E/N is a data to evaluate insulation strength of a gas and is presented in this paper for various mixture ratios of $SF_6-N_2$ mixture gases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.375-380
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• 2005

CF₄ molecular gas is used in most of semiconductor manufacture processing and SF/sub 6/ molecular gas is widely used in industrial of insulation field. but both of gases have defect in global warming. C₃F/sub 8/ gas has large attachment cross-section more than these gases, moreover GWP, life-time and price of C₃F/sub 8/ gas is lower than them, therefor it is important to calculate transport coefficients of C₃F/sub 8/ gas like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient and critical E/N. The aim of this study is to get these transport coefficients for imformation of the insulation strength and efficiency of etching process. In this paper, we calculated the electron drift velocity (W) in pure C₃F/sub 8/ molecular gas over the range of E/N=0.1∼250 Td at the temperature was 300 K and gas pressure was 1 Torr by the Boltzmann equation method. The results of this paper can be important data to present characteristic of gas for plasma etching and insulation, specially critical E/N is a data to evaluate insulation strength of a gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.773-778
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• 2001

In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in SF$_{6}$ and SF$_{6}$-Ar mixtures have described. The ionization and attachment coefficients in pure SF$_{6}$ and SF$_{6}$-Ar mixtures have been calculated over the range of 10$_{6}$ molecule and for Ar atom proposed by other authors. The transport coefficients for electrons in (0.2%)SF$_{6}$-Ar and (0.5%)SF$_{6}$-Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained in this work will provide valuable information on the fundamental haviors of electrons in weakly ionized gases and the role of electron attachment in the choice of better gases and unitary gas dielectrics or electro negative components in dielectric gas mixtures. gas mixtures.

• Environmental Engineering Research
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• v.13 no.3
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• pp.141-146
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• 2008

Transport of Escherichia coli ATCC 11105 through porous media was investigated in this study using two sets of column experiments to quantify the attachment-related parameters (sticking efficiency, attachment rate coefficient and filter factor). The first set of experiments was performed in quartz sand under different ionic strength conditions (1, 20, 100, 200 mM) while the second experiments were carried out in quartz sand mixed with metal oxyhydroxide-coated sand (0, 5, 10, 25%). The breakthrough curves of bacteria were obtained by monitoring effluent, and then bacterial mass recovery and attachment-related parameters were quantified from these curves. The first experiments showed that the mass recoveries were in the range of 13.3 to 64.7%, decreasing with increasing ionic strength. In the second experiments, the mass recoveries were in the range of 15.0 to 43.4%, decreasing with increasing coated sand content. The analysis indicated that the sticking efficiency, attachment rate coefficient and filter factor increased with increasing ionic strength and coated sand content. The value of filter factor in the first experiments ranged from 1.45 e-2 to 6.72 e-2 1/cm while in the second experiments it ranged from 2.78 e-2 to 6.32 e-2 1/cm. Our filter factor values are one order of magnitude lower than those from other studies. This discrepancy can be attributed to the size of sand used in the experiment. The analysis demonstrated that the travel distance of bacteria estimated using the filter factor can be varied greatly depending on the solution chemistry and charge heterogeneity of porous media.

• Korean Parent-Child Health Journal
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• v.7 no.1
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• pp.38-49
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• 2004

This study is to investigate the main factors influencing prenatal attachment. The research method is on the basis of descriptive correlational study, and data collecting period was from 11 to 29, November, 2003. The objects of this study were 100 pregnant women of two OBGY Hospitals in Masan. Using the SPSS/WIN 10.1 program the data were analyzed by t-test, ANOVA, Pearson correlation coefficient, stepwise multiple regression analysis. The result of this study was as follows : The mean score of prenatal attachment was 2.64, the mean score of physical discomforts, 1.61, the mean score of husband-wife attachment, 3.28, the mean score of psychosocial adjustment of pregnancy, 1.82. The degree of prenatal attachment according to general characteristics was significantly difference according to religion. The degree of prenatal attachment according to obstetrical characteristics was significantly difference according to Lamaze class, Taekyo. Significant correlations of prenatal attachment was found in both psychosocial adjustment of pregnancy, Taekyo, husband-wife attachment, Lamaze class, religion. Stepwise multiple regression analysis showed that 52% of the variance in prenatal attachment was significantly accounted by psychosocial adjustment of pregnancy(34%), Taekyo(6%), husband-wife attachment(5%), Lamaze c1ass(5%), and religion(3%). Further findings of this study support the development of creative strategies to enhance positive attachment relationship for pregnant woman.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.793-805
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• 2012

This study investigated the influence of mother and peer attachment on conflict resolution strategies of children. Following research questions were established. First, what is the influence of mother and peer attachment on conflict resolution strategies of children? Second, does the influence of mother and peer attachment on conflict resolution strategies of children differ according to sex? Third, what is the relative influence of mother and peer attachment on conflict resolution strategies of children? 485 fifth graders(male, 184; female, 163) from elementary schools located in Busan participated in this study and completed Inventory of Parent and Peer Attachment and Conflict Resolution Strategies Scale. Collected data were analyzed using t-test, Pearson Correlation Coefficient, Simple Regression and Multiple Regression Analysis. Major findings of this study were summarized as follows: First, both mother and peer attachment influenced on compromising and integration, avoiding and obliging strategies although the degree of influence were different. Second, the influence of mother and peer attachment on conflict resolution strategies differ according to gender. Third, the influence of peer attachment on conflict resolution strategies were greater than the one of mother attachment. Finally the significance of this study were presented with comments on limitations of this study.

• Journal of East-West Nursing Research
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• v.17 no.2
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• pp.132-138
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• 2011

Purpose: The purpose of this study was to explore the relationship among suicidal ideation, parental attachment, and self-identity of college students. Methods: This study was designed as a descriptive correlational research. The participants were 314 college students in Gyeongbuk province. Data were collected from September 23 to Oct 5 in 2009 using a structured questionnaire. Data were analyzed by t-test, ANOVA, and Pearson correlation coefficient using SPSS WIN (Version 12.0). Results: Suicidal ideation showed negative correlations with maternal and paternal attachment (r=-.20, p<.001; r=-.24, p<.001, respectively) as well as self-identity (r=-.37, p<.001). Self-identity had positive correlations with maternal and attachment (r=.16, p=.006; r=.23, p<.001, respectively). Conclusion: The findings suggest that suicidal ideation may be decreased when college students have higher parental attachment and self-identity. Strategies to improve parental attachment and self-identity are needed in near future.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.283-291
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• 2012

The aim of this study is to explore the structural relationship between recognition to environmental factor and place attachment of the users of temple forest trail in Gyeongju National Park, and to suggest political implications on conservation management of National Park from the viewpoint of landscape attachment. Survey with a structured questionnaire was implemented to visitors to the Bulkuksa, a representative temple in Geyongju National Park. Structural equation model was developed from the analysis of collected data. Results showed that place dependence positively affected place attachment in significance, whereas place identity did not significantly affect place attachment. Place attachment was affected rather by place dependence(path coefficient=0.55). Place attachment positively affected the recognition of environmental factors in significance. Landscape use factors compared to facility use factors were affected rather by place attachment(path coefficient=1.01). This result verified the importance of landscape factors of National Park, and suggested a management plan focused on the landscape conservation of forest trail of traditional temple.

• The Journal of Korean Society for School & Community Health Education
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• v.13 no.1
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• pp.33-43
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• 2012

Objectives: The study has a purpose of contributing to understanding children of multi-cultural families and healthy development of children by examining influences of parental attachment perceived by the children on their anger trait and anger expressions. Methods: The data were collected from 113 students in grade 4~6, and analyzed using descriptive statistics, t-test, pearson correlation coefficient by the SPSS/PC 18.0 program. Results: The result showed the stable attachment with parents significantly influences children's anger and expression(anger out/control). And mother's attachment was significantly stronger than father's attachment, especially mutual trust and communication. Father's attachment had significantly negative influences state-trait anger and anger out/in, and mother's attachment had significantly negative influences state-trait anger and anger out. Actually father's attachment had stronger influences children's anger and anger expression. Conclusions: There was relationship between father's attachment and anger trait/ expression by children of multi-cultural families. For the effective management of multi-cultural children's anger, programs focusing on improving father-child relationships need to be established.