• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.61-71
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• 2016

The purpose of the research is to identify the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria as leguminous woody plants for the cut-slope revegetation. To investigate the coverage ratio and appearance frequency, we divided Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria into five treatment groups with various quantities of $0.0g/m^2$, $1.0g/m^2$, $2.4g/m^2$, $3.8g/m^2$, and $5.2g/m^2$. For each treatment group, we mixed the identical quantities of herbaceous flowers (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena and Pennisetum alopecuroides) seeds and cool-season turfgrasses (Festuca arundinacea and Poa pratensis) seeds. In this result, as the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria increased in the spray, the coverage ratio for leguminous woody plants appeared to increase whereas the coverage ratio decreased in herbaceous flowers and cool-season turfgrasses. However, when the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria exceeded $3.8g/m^2$ in the spray, the coverage ratio of leguminous woody plants rather decreased compared to four treatment groups less than $3.8g/m^2$ seeding ratio. Based on the longitudinal data of coverage ratio in five treatment groups, we observed the gradual process of a short-term succession in which the dominant species shifted in the following order: First, cool-season turfgrasses; Second, herbaceous flowers; Third, leguminous woody plants. Comparing the appearance frequency of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria, Lespedeza cyrtobotrya appeared more frequent in 2014 whereas Indigofera pseudo-tinctoria appeared to be relatively more frequent in 2015. As a result, Indigofera pseudo-tinctoria was discovered to be a dominant species among woody plants. In this study, we observed that the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria was $2.4g/m^2{\sim}3.8g/m^2$. Moreover, the coverage ratio of 29.1%~35.4% and appearance frequency of 4.6plants~5.8plants were found in the condition of optimal seeding quantity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.646-652
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• 2017

The objective of this study was to verify the longitudinal reciprocal causal relationship between depression and the somatic symptoms of depression among adolescents through an autoregressive cross-lagged model using data from the Korean Children & Youth Panel Survey. The subjects of this study included 1,968 adolescents, who participated in the second, fourth, and sixth Korean Children & Youth Panel Surveys. The results showed that both depression and the somatic symptoms of depression at a previous point in time affect depression and the somatic symptoms of depression at a later point in time. It was also found that depression at a previous point in time has a cross-lagged effect on the somatic symptoms of depression at a later point in time, implying that more severe depression at a previous point in time leads to increased severity of somatic symptoms at a later point in time. It was found that the somatic symptoms of depression at a previous point in time have a cross-lagged effect on depression at a later point in time, indicating that more severe somatic symptoms of depression at a previous point in time lead to increased severity of depression at a later point in time. This study is significant in that it provides baseline information about nursing interventions for adolescent mental health.

• The Journal of the Korea Contents Association
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• v.17 no.8
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• pp.209-225
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• 2017

This study examines the effect of residential and neighboring environment on the residents' social exclusion in Daejeon Chokbangchon, the city's slum area. Based on GIS methodology with residents' addresses and other characteristics, this study finds out the feminization and the ageing trends in the central part of this area. Besides, longitudinal data between 2007 to 2016 shows this area's depopulation resulting in people's spread into other parts of the city. This study took pictures of 252 images of in the streets and indoors, analysed them and defined the problems of residential and neighboring environment. According to this picture analysis, the predicaments of this area was categorized into 4 types such as appearance-hygiene, narrowness-lack of residential functions, safety-privacy violation and stigma. This area ranging 1 km from north to south adjacent with Daejeon railway station was divided into 4 sections with different main problems. The follow-up survey for residents living in each section showed each section was different in work state, neighbor satisfaction, stigma and social exclusion. Finally, residential satisfaction was found to be the most important affecting factor on social exclusion. Based on these results, this study suggests government's housing policy on this area to be more enthusiastic and specific to cope with each problems of sections.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.123-134
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• 2017

This study examines the Korean Education Longitudinal Study 2005 7th-9th year data to analyze the university life of transfer students prior to their transferring by comparing them to that of non-transfer students. This study used two types of comparison groups: The first comparison group encompasses all who did not transfer and the second group was 1:1 matched sample of students who were enrolled in the same universities in the 7th year and were of the same gender. The 7th and 8th year experiences were compared, respectively. According to the result, transfer students in their previous universities compared to non-transfer students demonstrated higher grade point average, active class participation, and more interaction with faculty outside the class. On the other hand, these students demonstrated relatively lower satisfaction in university life, lower sense of belonging, and lower participation in student unions, campus events, and other student activities. They also tended to have less interaction with their colleagues. In other words, transfer students showed high competency and interests in academic activities like managing good grades and interacting with faculty but showed less interest in social activities such as interacting with peers and engaging in various campus activities. It is necessary to develope programs to help transfer students to adapt to school efficiently by utilizing the results of this study.

• Nutrition Research and Practice
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• v.14 no.4
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• pp.365-373
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• 2020

BACKGROUND/OBJECTIVES: To assess the longitudinal associations of the antioxidant capacity of zinc and body mass index (BMI) with serum uric acid (SUA) in South Korean children. SUBJECTS/METHODS: Using follow-up data from the Ewha Birth and Growth Cohort, we included subjects who were seen at 3 and 7 years of age (n = 183; 90 boys, 93 girls). Daily zinc intake and BMI were assessed at 3 and 7 years of age. SUA measured at 7 years was used as the outcome variable. Using a general linear model, the effects of dietary zinc intake and BMI on SUA were assessed. We also assessed the combined effect of early dietary zinc intake and BMI on SUA in children. RESULTS: The dietary zinc intake at 3 years of age was negatively correlated (ρ = -0.18, P = 0.04), whereas the BMI at 7 years of age was positively correlated (r = 0.18, P = 0.01), with the SUA level at 7 years of age. The dietary zinc intake level at 3 years of age and the BMI level at 7 years of age were, together, significantly related to SUA in children at 7 years of age. SUA was lower in group 1 (normal-weight, high-zinc group) than in the other two groups (group 2: normal-weight, low-zinc and overweight, high-zinc group; and group 3: overweight, low-zinc group). Our results demonstrate the combined effect of zinc intake and BMI on SUA. The combined association remained significant in both the crude and adjusted models (P < 0.01). CONCLUSIONS: SUA was related to combined BMI and dietary zinc intake, and increased zinc intake and normal body weight had a beneficial effect on reducing SUA in children.

• Polymer(Korea)
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• v.36 no.3
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• pp.281-286
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• 2012

Experimental study was performed regarding the effects of disc-like filler orientation and contents on the coefficient of thermal expansion (CTE) of polypropylene composites using the three dimensional ellipsoids ($a_1$ > $a_2$ > $a_3$) analyzed by two aspect ratios(${\rho}_{\alpha}=a_1/a_3$and ${\rho}_{\beta}=a_1/a_2$). Measured data were compared with the theoretical approaches proposed by Lee et al. Mica and talc were useed as disk-like fillers in the composites. As experimental results, ${\alpha}_{11}/{\alpha}_m$ decreased down to ca. 0.56 with mica content of 20 wt% and the aspect ratios, ${\rho}_{\alpha}=13.5$, ${\rho}_{\beta}=1.8$. However, ${\alpha}_{33}/{\alpha}_m$ increased to more than 1. In the case of talc, ${\alpha}_{11}/{\alpha}_m$ decreased to ca. 0.63 with 20 wt% and ${\rho}_{\alpha}=3.7$, ${\rho}_{\beta}=1.4$. Finally, the longitudinal CTEs (${\alpha}_{11}$) of polypropylene composites decreased as filler contents increased, but normal CTE (${\alpha}_{33}$) increased in the low filler contents like the theory.

• Journal of Technology Innovation
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• v.24 no.1
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• pp.1-24
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• 2016

This study examined 142 electronic components, video, audio, and communications equipment manufacturers (KSIC 32) out of all the SMEs that responded to the Survey on Technology of the Small and Medium Enterprises in both 2005 and 2007 and empirically analyzed how the external resources utilization and the absorptive capability affected the management and the innovation performance in two years as well as how the absorptive capability moderated these relationships. According to the results of analysis, the external resources utilization, as measured by the technology collaboration and the governments R&D subsidies, did not have a significant impact on performance whereas R&D investment showed a positive (+) influence on the sales and R&D personnel ratio, negative (-). On the other hand, the moderating effect of absorptive capability varied by measurement method and independent variables. That is, when a technology collaboration takes place, the performance improved with the increase of R&D investment but R&D personnel ration had an opposite effect. The companies whose performance improved as the government R&D subsidies increase are those with low R&D investment or high R&D personnel ratio. These results demonstrate that the SME's external resources utilization cannot replace the internal and that the absorptive capability needs to be accumulated to maximize the effectiveness of external resources utilization. Also, the technology collaboration requires SME's aggressive investment in R&D and the government R&D subsidies turn out to be more helpful for the companies that already have the R&D personnel but have been unable to develop their own technology due to insufficient funds. This study has limitations in that it was conducted within the limited industry categories and samples, but has overcome those of the existing researches by identifying causal relationships through the use of longitudinal data.

• Korean Parent-Child Health Journal
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• v.3 no.2
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• pp.1-17
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• 2000

The purpose of this study was to recognized the sleep activity patterns of the normal infants in Korea. The subject were 41 normal infants who were below 8 weeks old and were born in Taegu city and Kyungbuk province. The measuring instrument the sleep activity was NCASA translated by the Korean-parent-child Health Academic Association. The data that were collected from April, 18 1999 to January 1, 2000 were analysed by the SPSS 7.5 program. The results of the study was summarized as follow; 1) The mean amount of total sleeping hours per day was decreased from $16.27{\pm}1.96$ hr at the 1st week, to $15.19{\pm}2.39$ hr at the 2nd week, to $13.66{\pm}2.40$ hr at the 3 week but increased to $16.55{\pm}5.77$ hr at the 4-8 week after birth. 2) The mean frequency of feeding was increased to $9.43{\pm}2.79$ times at the 3rd week but decreased to $7.55{\pm}1.23$ times at the 4-8th week after birth. 3) The regularity of day time sleep was decreased from 50.00% to 19.79% and that of night time sleep was increased from 51.79% to 72.92%. 4) The regularity of feeding was increased from 30.42% at the 1st week to 50.07% at the 2nd week but decreased 26.34% at the 4-8th week after birth. 5) The longest period of day time sleep was decreased to $2.39{\pm}0.42$ hr at the 3rd week but increased $2.47{\pm}0.69$ hr at the 4-8th week after birth. The longest period of night time sleep was decreased to $2.58{\pm}0.67$ hr at the 2nd week but increased to $3.00{\pm}1.32$ at the 3rd week and $4.30{\pm}1.16$ hr at the 4-8th week after birth. 6) At the 1st week, the 2nd week, the 3rd week after birth, the frequency of day time feeding was positively correlated with the frequency of night time feeding($R_{1week}=0.948^{**}$, $R_{2week}=0.927^{**}$, $R_{3week}=0.779^{**})$. At the 4-8th week after birth, the frequency of night time feeding was negatively correlated with the amount of night time sleep ($R_{4week-8week}=0.875^{*}$). On the basis of above findings, the following is suggested; It is need a longitudinal and transcultural study which are designed for children's sleep and feeding.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.61-69
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• 2004

The bridge piers under service suffered a brittle failure due to the deterioration of lap-spliced longitudinal reinforcement without developing its flexural capacity or ductility. The earthquake induced lateral force results in tension which causes bond-slip failure at the lap-spliced region in circular bridge piers. In this case, such a brittle failure can be controlled by the seismic retrofit using FRP laminated circular tube. The retrofitted piers using FRP laminated circular tube showed significant improvement in seismic performance due to FRP's confinement effect. This paper presents the analytical results on the seismic strengthening effect of circular bridge piers with poor lap-splice details and strengthened with FRP laminated circular tube. FRP's confinement effect is predicted by the classical elasticity solution for the laminated circular tube manufactured with several layers. The FRP laminated circular tube induces the flexural failure instead of a bond-slip failure of the circular reinforced concrete piers under seismic induced lateral forces. To investigate the correctness and effectiveness of analytical solution derived in this study, the analytical results were compared with the experimental data and it was confirmed that the results were correlated well each other, The effects on the confinement of FRP laminated circular tube, such as the number of layers, the fiber orientations, and the mechanical properties, were investigated. From the parametric study, it was found that the number of layers, the fiber orientations, and the major Young's modulus (E11) of the FRP laminated circular tube were the dominant parameters affecting the confinement of reinforced concrete circular bridge piers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.19-28
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• 2010

This study was designed to investigate the effect of increased blood and tibia lead on the change of bone mineral density in retired male lead workers. One hundred nine retired male lead workers who worked in 4 different lead industries and 51 nonoccupationally lead exposed male subjects were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured by broadband ultrasound attenuation(BUA) at left calcaneous bone area with broadband ultrasound attenuation method of QUS-2(Metra Biosystems Inc, USA). Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.711) and these two variables were negatively correlated with BUA in bivariate analysis. BUA and tibia lead showed significant main effects on the change of blood lead after adjusting covariates. The effect modification by the level of BMD (low: lower than the median of BUA and high: higher than the median of BUA) was observed between the association of tibia lead and blood lead after adjustment of covariates. The subjects who had higher BMD seemed to have lower blood lead by the increase of tibia lead than those of lower BMD. In the multiple regression analysis of blood lead and tibia lead on BUA after adjustment of covariates, only blood lead showed statistically significant effect on BUA. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.