• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.213-213
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• 2016

현재 반도체 산업에서는 디바이스의 고 집적화, 고 수율을 목적으로 패턴의 미세화 및 웨이퍼의 대면적화와 같은 이슈가 크게 부각되고 있다. 다중 패터닝(multiple patterning) 기술을 통하여 고 집적 패턴을 구현이 가능해졌으며, 이와 같은 상황에서 각 패턴의 임계치수(critical dimension) 변화는 패턴의 위치 및 품질에 큰 영향을 끼치기 때문에 포토마스크의 임계치수 균일도(critical dimension uniformity, CDU)가 제작 공정에서 주요 파라미터로 인식되고 있다. 반도체 광 리소그래피 공정에서 크롬(Cr) 박막은 사용되는 포토 마스크의 재료로 널리 사용되고 있으며, 이러한 포토마스크는 fused silica, chrome, PR의 박막 층으로 이루어져 있다. 포토마스크의 패턴은 플라즈마 식각 장비를 이용하여 형성하게 되므로, 식각 공정의 플라즈마 균일도를 계측하고 관리 하는 것은 공정 결과물 관리에 필수적이며 전체 반도체 공정 수율에도 큰 영향을 미친다. 흔히, 포토마스크 임계치수는 플라즈마 공정에서의 라디칼 농도 및 식각 선택비에 의해 크게 영향을 받는 것으로 알려져 왔다. 본 연구에서는 Cr 포토마스크 에칭 공정에서의 Cl2/O2 공정 플라즈마에 대해 O2 가스 주입량에 따른 식각 선택비(etch selectivity) 변화를 계측하여 선택비 제어를 통한 Cr 포토마스크 임계치수 균일도 향상을 실험적으로 입증하였다. 연구에서 사용한 플라즈마 계측 방법인 발광분광법(OES)과 optical actinometry의 적합성을 확인하기 위해서 Cl2 가스 주입량에 따른 actinometer 기체(Ar)에 대한 atomic Cl 농도비를 계측하였고, actinometry 이론에 근거하여 linear regression error 1.9%을 보였다. 다음으로, O2 가스 주입비에 따른 Cr 및 PR의 식각률(etch rate)을 계측함으로써 식각 선택비(etch selectivity)의 변화율이 적은 O2 가스 농도 범위(8-14%)를 확인하였고, 이 구간에서 임계치수 균일도가 가장 좋을 것으로 예상할 수 있었다. (그림 1) 또한, spatially resolvable optical emission spectrometer(SROES)를 사용하여 플라즈마 챔버 내부의 O atom 및 Cl radical의 공간 농도 분포를 확인하였다. 포토마스크의 임계치수 균일도(CDU)는 챔버 내부의 식각 선택비의 변화율에 강하게 영향을 받을 것으로 예상하였고, 이를 입증하기 위해 각각 다른 O2 농도 환경에서 포토마스크 임계치수 값을 확인하였다. (표1) O2 11%에서 측정된 임계치수 균일도는 1.3nm, 그 외의 O2 가스 주입량에 대해서는 임계치수 균일도 ~1.7nm의 범위를 보이며, 이는 25% 임계치수 균일도 향상을 의미함을 보인다.

• Journal of the Korean Regional Science Association
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• v.31 no.3
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• pp.55-77
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• 2015

The purpose of this research is to analyze the influence of the regional location factors to the lifecycle of manufacturing firms in the Seoul Metropolitan Area. A firm has a lifecycle in common like a household. The firm's lifecycle is divided into 4 sections such as formation, dissolution, growth and decline for the manufacturing firms as light industry, heavy industry and high-tech industry. In addition, the regional location factors are divided into 4 categories. As a result of this research, there are differences for the statistically significant location factors. In addition, the value for the explanation ability of each multiple linear regression model (adj. $R^2$) was high in the formation and growth sections than in dissolution and decline sections. It means that the local governments need differentiated policies considering their regional characteristics for the location factors by firm's lifecycle when they established policies for industry or job. From the view point of the public sectors, it is much important to focus on formation and growth of firms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4758-4767
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• 2015

This study investigates the relationship between occupational stress, depression, drinking among heavy industrial male workers. The participants of this study were 312 workers in a local heavy industry. The data were collected by self-report using questionnaires from May to June, 2014. The data were analyzed using descriptive statistics. t-test, ANOVA, and pearson correlation coefficient, scheffe test, stepwise multiple linear regression with the SPSS/WIN 20.0 program. The total mean scores of occupational stress on the subjects were $53.77({\pm}6.33)$, depression were $12.10({\pm}7.44)$, drinking were $10.32({\pm}7.55)$. The study showed that drinking is positively correlated with occupational stress, depression. Also drinking explained 15.9% of occupational stress in heavy industrial male workers. This study provides baseline data for the preparation of management strategies that can address the occupational stress, depression, drinking of heavy industrial male workers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4679-4688
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• 2015

The purpose of this study was to identify the factors influencing sexual consciousness, gender egalitarianism and awareness levels of sexual harassment among college students. Methods: As a descriptive, correlative study, the data was collected from 274 college students. The copies of the questionnaire were collected from April 23 to 30, 2015. The data was analyzed using a t-test, ANOVA, Pearson correlation coefficients and multiple linear regression. Results: Sexual consciousness, gender egalitarianism and sexual harassment awareness levels averaged 3.00 (range of score 1-5), 1.97(1-4) and 4.09 (1-5), respectively. Awareness levels of sexual harassment had a positive correlation with sexual consciousness, and a negative correlation with gender, major field of study, living patterns, and gender egalitarianism. Conclusion: This study has identified sexual consciousness and gender egalitarianism, as well as the associated influencing factors, among college students. The results of this study are expected to be used as basic data for developing strategies and programs for the prevention of sexual harassment among college students.

• The Journal of Internal Korean Medicine
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• v.36 no.3
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• pp.348-360
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• 2015

Objectives From observing the tongue of a patient, one can assess the health status; this method has been frequently used in traditional Korean Medicine (KM) clinics. In particular, KM posits that the color of the tongue is highly related to digestive functions. In this study, the color of tongue and heart rate variability (HRV) were compared between chronic dyspepsia (CD) patients and healthy subjects. Methods Healthy subjects and CD patients with functional dyspepsia (FD), gastroesophageal reflux disease (GERD), or chronic gastritis (CG) were enrolled for the study. Profile view images of the tongue were acquired by using a computerized tongue image acquisition system (CTIS). The color of the tongue body was extracted from the non-coated region on the tongue images. Results Color differences in CIE L*a*b* color space between the three sub-types of CD patients and healthy subjects were analyzed by using multiple linear regression analysis with age and sex as the factors. The variable b* was significantly lower in GERD patients than in the controls (p=0.017). Variable a* was significantly lower in CG than in the controls (p=0.03). No significant difference was seen between FD and controls. In GERD, the tongue body seems to be intense red in color; in CG, pale red. Frequency domain analysis showed that HF was significantly lower in GERD patients than in the controls (p=0.041). Conclusions The color of the tongue body and HF of HRV can be used for diagnosing digestive functions in health care.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1619-1627
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• 2015

The purpose of this study was to examine the relationship between the safety awareness and safety practice behavior of adult learners who participated in "civic safety culture college" was held in Changwon city. We carried out a questionnaire survey that was targeted at 150 citizens, but 132 citizens were included finally. Data collected were analyzed with SPSS 21.0 statistical program. Analysis methods were t-test, one way ANOVA, Scheffe test, Pearsons correlation coefficient, and multiple linear regression. The results were as follows. First, safety awareness point was an average of 4.17 point which was higher levels. Area showing the highest safety awareness was fire safety. Safety practice behavior point was an over intermediate level of an average of 3.58 point. Second, safety practice behavior had statistically significant difference according to sex(t=2.58, p=.01), education(t=-2.57, p=.01), job(t=-1.96, p=.05), housing(t=3.65, p<.001). Third, there was a positive correlation between home safety awareness(r=.28, p<.001), traffic safety awareness(r=.37, p<.001), fire safety awareness(r=.37, p<.001), emergency care awareness(r=.45, p<.001) and safety practice behavior. Fourth, safety practice behavior was related to the emergency care awareness(${\beta}$=.34, p=.002), this factor accounted for 19.5% of the variability of the safety practice behavior. These results are expected to be very important baseline data for many different businesses and program development for strengthening of safety awareness and spreading of safety culture in Changwon city.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.141-154
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• 2016

Objectives: The purpose of the study was to identify factors influencing on nursing students' end-of-life care attitude. Methods: A sample of convenience of 147 nursing students, Instrument included death anxiety, death attitude, Self-esteem, Life satisfaction, end-of-life care attitude. Results: A significant negative correlation was found among end-of-life care attitude, death anxiety, death attitude. Death anxiety(${\beta}$=-.392), self-esteem(${\beta}$=.179) & experience of learning(${\beta}$=-.227) about death were significant predictive variables. This variables accounted for 18.7% of the variance in end-of-life care attitude. Conclusions: Based on the Findings of this study, it can be used to develop educational programs for end-of-life care.

• Journal of Soil and Groundwater Environment
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• v.24 no.6
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• pp.1-8
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• 2019

This study evaluated the relative extraction ratio (RER) of As and heavy metals (Cd, Cu and Pb) in paddy soils using the two types extractant, 0.05 M EDTA and 0.43 M HNO₃. The RER was calculated by dividing the concentrations of metals obtained by 0.05 M EDTA or 0.43 M HNO₃ extraction by those obtained by aqua regia extraction. The RER of 0.43 M HNO₃ was larger than that of 0.05 M EDTA. Correlation analysis indicated there was statistically significant correlation (p<0.001) between the concentration in aqua regia and 0.05 M EDTA or 0.43 M HNO₃. Especially, Cd showed the higher correlation than other metals. Stepwise multiple linear regression analyses indicated soil pH, CEC, organic matter content, and soil texture all influenced the metal extraction rates and bioavailability of the metals.

• Journal of Preventive Medicine and Public Health
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• v.43 no.1
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• pp.62-72
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• 2010

Objectives: To identify factors associated with cancer screening intention using the Theory of Planned Behavior (TPB). Methods: Among 55,920 eligible persons for National Cancer Screening Program (NCSP) in J city, 1,100 individuals were contacted. Of these, 797 were interviewed using a structured questionnaire. Thirty-six responses were excluded due to incomplete data. The remaining 761 completed questionnaires were analyzed to find factors associated with cancer screening intention. Results: Cancer screening intention was significantly associated with behavioral attitude (p<0.01) and subjective norm (p<0.01), but not with perceived behavioral control (p=0.29) in the TPB model. These three constructs explained 29.7% of cancer screening intention in multiple linear regression analysis. External factors such as socio-demographic status, health and health behavior variables explained 8.9% of screening intention. Among them, household monthly income, past cancer screening experience, exercise and daily eating habit were significantly associated with screening intention. Conclusions: Cancer screening intention may be influenced by focusing attitude, subjective norm in TPB model and other external factors. However, further studies are warranted to identify factors influencing cancer screening intention and behavior.

• Journal of the Korean earth science society
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• v.23 no.7
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• pp.587-596
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• 2002

A super ensemble model was developed for the seasonal prediction of regional precipitation in Korea using the lag correlated large scale predictors, based on the empirical orthogonal function (EOF) analysis and multiple linear regression model. The predictability of this model was also evaluated by cross-validation. Correlation between the predicted and the observed value obtained from the super ensemble model showed 0.73 in spring, 0.61 in summer, 0.69 in autumn and 0.75 in winter. The predictability of categorical forecasting was also evaluated based on the three classes such as above normal, near normal and below normal that are clearly defined in terms of a priori specified by threshold values. Categorical forecasting by the super ensemble model has a hit rate with a range from 0.42 to 0.74 in seasonal precipitation.