• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.102-103
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• 2008

Magnetron Sputtering, MOCVD, Thermal Evaporation에 의해 성장된 ZnO layer에 대한 Dependency Temperature Photoluminescence (PL)를 이용하여 비교 분석을 통해 Deep level emission에 대해 연구하였다. Sputter에 의해 성장된 ZnO 박막은 Violet, Green, Orange-red 영역의 $Zn_i$, $V_o$, $O_i$의 defect에 의한 Deep level emission을 보였고, MOCVD에 의해 성장된 박막은 비교적 산소양이 낮은 성장 조건에서는 blue-green 영역에서, 산소양이 높은 조건에서의 박막은 Orange-red 영역의 Deep level emission을 보였다. Blue-green 영역에서의 emission은 온도가 증가함에 따라 다른 Barrier를 보였는데, 이는 $V_{Zn}$와 $V_o$에 의한 것임을 알 수 있었다. 한편, ZnO nanorods는 $V_o$에 의한 Green 영역에서의 Deep level emission을 보였다.

• Journal of the Korean School Mathematics Society
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• v.22 no.4
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• pp.483-500
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• 2019

This study compared and analyzed the van Hiele levels of geometry contents in middle school mathematics textbooks and those of students' thinking. As the mathematics curriculum was revised recently, the amount of contents in the geometry area were reduced, but the van Hiele level did not change much, and the gap between the van Hiele level of geometric contents presented in the textbooks and the level of students' geometric thinking still remained unchaged. The van Hiele levels of the geometric contents in the textbooks were distributed in the levels of 1, 2, 3 in the first grade, and 2, 3, 4 in the second and third grade. In the case of the first grade, 69% of the students were less than or equal to level 2, and 73.7% and 47.6% of the students in the second and third grades were less than or equal to level 3, respectively. Especially, in the case of the second and third grade, the ratio of the 4th level of the contents presented in the textbook is higher than the problem, which can cause difficulties for the students.

• Journal of The Korean Association For Science Education
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• v.14 no.2
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• pp.225-235
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• 1994

Concidering environmental education as an ultimate resolution for environmental problems, we conducted a study focusing on affective matters. An instrument was developed to evaluate attitudes of elementary and middle school students toward environmental problems. To develop a reliable Likert-type evaluation instrument scale with which emotional intensity could be judged, mean, standard deviation, response frequency distribution, discrimination index, reliability were calculated. As a result, 21 statements for recognition level and 14 statements for behavioral level were made(The Cronbach alpha coefficient of the instrument was .786). This instrument was used to evaluate 5th and 6th grade elementary school students and 1st and 2nd grade middle school students(total number of subjects was 980). The result of this survey can be summarized as follows. 1. Students recognized the seriousness of environmental problems but they did not behave in such a manner as to prevent it. 2. As a result of t-test, behavioral level score of elemenatary school students was significantly higher than that of middle school students(p<.001). 3. This study showed that there was a significant correlation between the recognition level score and the behavioral level score(r=.386, p<.001). 4. Two-Way ANOVA was used to analyze that there was any significant difference according to grade and sex. The results were as follows. (1) No significant difference was found in total score. (2) On recognition level, female students' score was signigicantly higher than that of male students(p<.01). (3) On behavioral level, higher-grade students' score was lower than that of lower-grade-students (p<.001).

• Journal of the Korean Society of School Health
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• v.23 no.1
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• pp.41-52
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• 2010

Purpose: The objective of this study is to investigate the relationship between middle and high school students' internet addiction, social support, self-efficacy and school life adjustment. Data were collected by self-administered questionnaires at middle and high school students located in Seoul and the metropolitan areas. Methods: The response rate is 94.8% (474 cases). The internet addition was measured by K Scale. The various methods of analysis were used, for example, frequency analysis, t-test, analysis of variance, and multiple regression analysis. Results: First, the mean score of internet addiction level is 2.07 in 5 Likert scale. the internet addiction level of the male students are higher than female students (p<.05). Second, as a result of classification of internet addiction groups by K Scale, 11 students (2.3%) are included in high risk group, 27 students (5.7%) are in potential risk group, 436 students (92.0%) are in general group. Third, the level of social support and self-efficacy of middle and high school students are very high. The difference of social support by internet addiction groups was not statistically significant. But, the difference of self-efficacy by internet addiction groups was statistically significant. The level of self-efficacy of the students in general groups are more higher than in high risk group and in potential risk group (p<.01). Fourth, the difference of school adjustment by internet addiction groups was very statistically significant. The level of school life adjustment of the students in general groups are more higher than in high risk group and in potential risk group (p<.01). Fifth, the internet addiction have a negative correlation with school life adjustment. And the social support and self-efficacy have a positive correlation with school life adjustment (p<.01). Finally, in stepwise multiple regression analysis, the internet addiction affects negatively on the school adjustment. And the support of teacher among three types of them affects positively on the school life adjustment. And the social self-efficacy among two types of them affects positively on the school adjustment (p<.01). Conclusion: to adjust desirably the school environment of the middle and high school students, optimal and efficient management of internet addiction was needed in the future and the improvement and promotion of social support and social self-efficacy of the students was also demanded.

• The Journal of Korean Society for School & Community Health Education
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• v.15 no.2
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• pp.13-22
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• 2014

Objectives: The purpose of this study was to identify drinking form and analyze affecting factors of emergency medical technology students. Methods: Data were collected by questionnaire and analyzed by using the SPSS WIN 18.0 and Multiple Linear Regression Analysis. Results: In factors of the monthly drinking frequency, start drinking(middle school), smoking, pocket money, education level of mother were statistically profitable(p<.05). In factors of the monthly drinking too much frequency, gender, education level of mother, start drinking(high school), economical level were statistically profitable(p<.05). In factors of subjective model of drinking, discord with parents, education level of mother, age were statistically profitable(p<0.05). Conclusion: Teacher and the authorities of school and government must know seriousness and importance of drinking and endeavor to solve the problem and prepare the political plan and solution.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.677-683
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• 2023

The purpose of the study was to estimate the trajectories of elementary school adjustment in grades 1 through 4. For the purpose, the Korean Children's Panel data were analyzed using potential growth model and the growth mixture model. As the result, the linear model was selected as the optimal model. The four potential groups were derived as trajectories: high-level maintenance, low-level maintenance, low-level increase, and high-level decrease. In terms of group distribution, the most children were in high-level maintenance group and then low-level maintenance, low-level increase, and high-level decrease in order. Based on the findings that trajectories of elementary school adjustment changes as children growth, we suggest that schools and families need to carefully investigate and support their school adjustment in individual levels.

• Child Health Nursing Research
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• v.14 no.1
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• pp.61-70
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• 2008

Purpose: The purpose of this study was to investigate the relationship between high school students' self-differentiation, family function and their level of stress. Method: A questionnaire which consisted of questions on general characteristics of the high school students, and 36 questions on self-differentiation, 17 questions on family function, and 37 questions on level of stress was used to collect the data. Participants were 201 second grade high school students from Bucheon City. Descriptive statistics, T-test, ANOVA, correlation and multiple regression were used with SPSS 10.0 to analyze the data. Results: The mean scores for self-differentiation, family function, and levels of stress were 3.27, 3.39, and 2.61 respectively. The relationship between self-differentiation and level of stress revealed a significant negative correlation. The relationship between self-differentiation and family function showed a significant positive correlation. The relationship between family function and stress level showed a significant negative correlation. Conclusion: The results of the study show that variation in level of stress was related to family regression, recognition/emotional function, family projection, role recognition and emotional support and emotional cutoff which together explained 40.9% of the variance in level of stress.

• The Journal of Advanced Prosthodontics
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• v.3 no.4
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• pp.190-195
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• 2011

PURPOSE. This study evaluated the initial stability of different implants placed above the bone level in different types of bone. MATERIALS AND METHODS. As described by Lekholm and Zarb, cortical layers of bovine bone specimens were trimmed to a thickness of 2 mm, 1 mm or totally removed to reproduce bone types II, III, and IV respectively. Three Implant system (Br${\aa}$nemark System$^{(R)}$ Mk III TiUnite$^{TM}$, Straumann Standard Implant SLA$^{(R)}$, and Astra Tech Microthread$^{TM}$-OsseoSpeed$^{TM}$) were tested. Control group implants were placed in level with the bone, while test group implants were placed 1, 2, 3, and 4 mm above the bone level. Initial stability was evaluated by resonance frequency analysis. Data was statistically analyzed by one-way analysis of variance in confidence level of 95%. The effective implant length and the Implant Stability Quotient (ISQ) were compared using simple linear regression analysis. RESULTS. In the control group, there was a significant difference in the ISQ values of the 3 implants in bone types III and IV (P<.05). The ISQ values of each implant decreased with increased effective implant length in all types of bone. In type II bone, the decrease in ISQ value per 1-mm increase in effective implant length of the Br${\aa}$nemark and Astra implants was less than that of the Straumann implant. In bone types III and IV, this value in the Astra implant was less than that in the other 2 implants. CONCLUSION. The initial stability was much affected by the implant design in bone types III, IV and the implant design such as the short pitch interval was beneficial to the initial stability of implants placed above the bone level.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.21-32
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• 2021

This paper aims to investigate the relationship between country-level institutional quality and public debt in the context of Pakistan. The hypotheses of this study were assessed by using the country-level institutional quality data for Pakistan throughout the years from 1996 to 2018. Data came from the World Databank, IMF and Worldwide Governance Indicators databases. For the analysis, ordinary least square, quantile regression and robust regression were employed to assess the factors influencing the public debt. The results of this study indicate that the factors of voice and accountability, regulatory quality, and control of corruption have a positive and significant relationship with public debt, while political stability, government effectiveness, and the rule of law have a negative and significant effect on public debt. Based on the findings, a weak country-level institutional quality poses a substantial market risk as it signals the existence of an unfavorable economic condition that raises public debt. It was also revealed that an improved performance of country-level institutional quality can lead to the improvement of financial market transparency, hence reduce public debt. In contrast to previous studies, the present study will be breaking ground in enhancing public insight regarding the impact of country-level institutional quality on Pakistan's public debt.

• East Asian mathematical journal
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• v.33 no.4
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• pp.333-351
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• 2017

Schools are expected to ultimately moderate the difference of inequality issues among social groups and reduce the achievement gaps. This study investigates this expectation, in particular, how students' mathematics achievements are influenced by their parents' education at the individual level and by collective responsibility for teaching at the school level as well as the interaction of the two. Using a two-level hierarchical linear model, this study indicates that a school collective responsibility has a larger positive effect on students' mathematics achievement when their parents' education level is high. This means that school's collective responsibility accelerates inequity in students' mathematics achievement. Knowing that collective responsibility has less of an effect on students whose parents' education is not high, researchers, schools, and school districts should continue to search for school effects that have more of a positive impact on the relationship between mathematics achievement for students whose parents' education is not high in order to have more equitable results for all students.