• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.475-483
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• 2019

Special chemical warfare agents are lethal gases that attack the human respiratory system. One of such gases are blood agents that react with the irons present in the electron transfer system of the human body. This reaction stops internal respiration and eventually causes death. The molecular sizes of these agents are smaller than the pores of an activated carbon, making chemical adsorption the only alternative method for removing them. In this study, we carried out a Computational Fluid Dynamics simulation by passing a blood agent: cyanogen chloride gas through an SG-1 gas mask canister developed by SG Safety Corporation. The adsorption bed consisted of a Silver-Zinc-Molybdenum-Triethylenediamine activated carbon impregnated with copper, silver, zinc and molybdenum ions. The kinetic analysis of the chemical adsorption was performed in accordance with the test procedure for the gas mask canister and was validated by the kinetic data obtained from experimental results. We predicted the dynamic behaviors of the main variables such as the pressure drop inside the canister and the amount of gas adsorbed by chemisorption. By using a granular packed bed instead of the Ergun equation that is used to model porous materials in Computational Fluid Dynamics, applicable results of the activated carbon were obtained. Dynamic simulations and flow analyses of the chemical adsorption with varying gas flow rates were also executed.

• (The) Korean Journal of Educational Psychology
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• v.31 no.1
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• pp.59-81
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• 2017

This study examined the relationship of grit, goal perception and academic adjustment of adult female students in a distance university. We additionally investigated how academic work-family conflict and social support influenced the grit-adjustment relationship. Grit is defined as passion and perseverance for long-term goals and it has been known as one of the predictors of adjustment indicators including academic achievement. A total of 642 female students in a distance university were participated in the survey and a Structural Equation Modeling (SEM) was utilized for data analysis. Results showed that our model fit data well, specifically, two components of grit (i.e. consistency of interest and perseverance of effort) positively predicted academic adjustment. Results from analyses of specific indirect effects revealed that consistency of interest was found to have a positive direct effect on academic adjustment while perseverance of effort had a positive indirect effect via goal perception, suggesting the discriminant predictability of grit's two components. Lastly, academic work-family conflict was found to negatively predict academic adjustment while social support predicted a positive academic adjustment via goal perception.

• Journal of Korea Entertainment Industry Association
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• v.15 no.6
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• pp.153-163
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• 2021

This study has a main purpose that closely examines the structural relationship among A Study on the Structural Relationship of Achievement Goal Propensity, Sports Confidence, and Perceived Performance Using the Mentoring System of High School Leaders. In order to achieve it, the sample from high school student participants were accumulated by using convenience sampling that chose taekwondo championship in national. The samples were 500 people. and we excluded unsuitable sheet like that were decided as untruthful one and an omission and unclear. So the final samples were 465 people. On the basis of that, The statistical techniques, spss 24.0 and amos 24.0 program have been used for the analysis as per research purpose. The statistical analysis used in the research for a data analysis includes frequency analysis, confirmatory factor analysis, reliability analysis, correlation analysis, and structure equation model analysis. The research has drawn the following conclusions, based on the above mentioned research method and its procedures: First, The mentoring influences the achievement goal orientation. Second, The mentoring influences the sport confidence. Third, The achievement goal orientation influences the perceived performance. Fourth, The sport confidence influences the perceived performance.

• Korean Journal of Culture and Social Issue
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• v.28 no.1
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• pp.23-41
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• 2022

This study aims to examine the mediating effects of paternal depression on the relationship between traditional gender role attitudes and the perceived maternal gatekeeping roles of fathers with young children. For this purpose, a survey was conducted by 366 married fathers who raises at least one child who is under seven years old. Mplus 7.0 was used to analyze the structural equation model, and the result showed that higher traditional gender role attitudes relate to more depressive symptoms, higher perceptions of maternal gate closing and lower perceptions of maternal gate opening. Also, more depressive symptoms were related to higher perceptions of maternal gate closing and lower perceptions of maternal gate opening. Additionally, the partial mediation effects of depression were observed in the relationship between traditional gender role attitudes and maternal gate keeping. Based on the findings, implications for therapeutic interventions were discussed, and recommendations for future research are presented.

• Journal of Korea Trade
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• v.27 no.3
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• pp.21-42
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• 2023

Purpose - This paper investigates the trade effect of the Korea-China Free Trade Agreement (KCFTA) which coincides with political conflicts between the two countries due to the deployment of the Terminal High Altitude Area Defense (THAAD) in Korea. The two events occurred in the same year and both are likely to affect trade between two countries but in opposite directions. Therefore, it is crucial to distinguish between the trade effects from the KCFTA event and those from the THAAD event to evaluate the true FTA effects. However, this would be difficult when using only annual data. Accordingly, ex post studies to examine the trade effects of KCFTA are lacking in trustworthiness while many ex ante studies that conjecture the positive trade effects neglect the THAAD deployment impact. This paper aims to fill that gap. Design/methodology - Given that the KCFTA and THAAD events occurred in the same year but in different months, we use the monthly data from 2000 to 2019 of Korea's exports to bracket this period. We employ the difference-in-difference (DID) method within a gravity equation specification that uses hi-dimensional fixed effects to address various endogeneity issues and seasonal effects. We identify the net impact of KCFTA ratification from these two near-simultaneous events to quantify the effects of trade liberalization between these two countries. Findings - After isolating the THAAD effects on trade, the analysis creates a positive and statistically significant coefficient estimate of the KCFTA impact. In contrast, failing to isolate the THAAD effect produced a negative and statistically significant coefficient estimate of the KCFTA impact. Our results indicate that KCFTA independently increased Korea's exports to China by 10.2%, but that this increase was fully mitigated by the THAAD event. Further, our results verify that unobserved heterogeneity and multilateral resistance are technically difficult to account for in those estimations as that rely solely upon annual data, as this type of data are inadequate to control for the potential for endogeneity. Originality/value - This paper is one of the first studies to carefully evaluate the net trade effects of the KCFTA on Korea's largest trading partner while isolating the impact of simultaneously occurred political events that may influence trade in opposing directions. Our findings indicate that the lack of prior evidence of positive trade effects of the KCFTA when using annual data may be attributed to a failure to identify the impact of each event separately. This analysis supports using the correct modeling specification to avoid misleading conclusions when evaluating any important international trade policy.

• 한국노년학
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• v.31 no.3
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• pp.795-811
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• 2011

Recently, an interest on how to moderate parenting stress of grandparents is rising according to rising depression of grandparents of grandparents and grandchildren family(GGF) because of parenting stress So, this study tried to analyze moderating effects by setting social support and stress coping behaviors as moderator variable in order to know how much parenting stress of grandparents would influence their depression. For this purpose, we selected 369 cases of grandparents who were being provided social welfare service and to 334 cases out of them, did multigroup analysis using hierarchical regression analysis and structural equation model under spss Vor. 19.0 program. Followings are the results. First, the more parenting stress was high, the more depression high. But when social support was high, parenting stress low. And the more parenting stress was high, faith dependence, negative emotional expression and passive evasion as stress coping behaviors also high while problem reestablishment low. Second, emotional support, information support, and material support as social support had moderating effects in which parenting stress influenced depression while appraisal support had not. Third, faith dependence and low passive evasion as stress coping behaviors had moderating effects in influence of parenting stress to depression while problem reestablishment has not. On the one hand, emotional expression was meaningless in explaining moderating effects in connection with parenting stress. Through these, we draw a social welfare practical implication that could lift moderating effect of social support and stress coping behavior in between parenting stress and depression of grandparents of grandparents and grandchildren Family.

• Asia Marketing Journal
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• v.9 no.1
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• pp.73-102
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• 2007

The paper aims to examine the relationships among a company's design, brand, and reputation orientations. DBR (Design, Brand, Reputation) have been regarded as invisible growth engines for companies and draws a lot of interests among Brand, PR and IR mangers recently. We have tested 3 hypotheses and have developed a relationship mechanism how to develop those three key intangible marketing assets. We have conducted 131 interviews with company managers who are involved in DBR activities, used Structural Equation Model (SEM) to estimate those relationships. It was found that a company's design orientation influenced the company's brand orientation positively and this brand one influenced reputation orientations consequently. However, design orientation does not show any significant relationship with a company's reputation orientations. Thus, there is a D->B >R chain mechanism concerning these 3 intangible marketing assets. Finally, the implications of this study and suggestions of further studies are discussed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.1
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• pp.21-30
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• 1997

The present study reports the density, growth and production of a razor clam, Sinollovacula constricta, which is known to be one of the important fishreies catches from the Korean tidal flat. The annual yield reached to about 6,000 metric tons per year till 1994. The study was conducted on the Hwaseong tidal flat located on the central west coast, 40 kilometers south-west from Seoul. The annual yield of the razor clam in this area reached to about 50% of the total catch from the whole Korean coast. Samples were colleted monthly at 14 occasions from May 1992 to August 1993. Density of S. constricta ranged from 92~165 individuals per square meter during the study period. General trend of decreasing density was observed when the animal became older, but an exception was the year class of 1991 whose density was lower than that of 1990. The size of the shell was clearly separated into two classes during fall and winter (from September to February), however, the maximum frequency of the length of small size classes moved to right after February. It indicates a fast growth of young clams from spring to summer. Fast growth of the shell could also be examined by the growth curve. The shell growth of the whole life span was described by the von Bertalanffy equation of $L_t=89.3{\times}[1{\exp}\{-0.58{\times}(t+0.73\}]$. The growth in flesh dry weight was well fitted to the Gompertz growth model with the equation, $W_t=5.00{\times}{\exp}\{-4.31{\times}{\exp}(-0.043{\times}t)\}$. The clam lost about 30% of the body weight during spawning in August. The annual production calculated based on the data from September 1992 to August 1993 amounted to 150 g $DW{\cdot}m^{-2}{\cdot}yr^{-1}$ which was 2~50 fold higher than those of other bivalves occurred in Korea. This estimate was patitioned by each year classes; 87.5 by 1992, 53.4 by 1991, 59.0 by 1990 and -30.0 g $DW{\cdot}m^{-2}{\cdot}yr^{-1}$ by 1989 year class.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.296-305
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• 2006

The adsorption and persistence of pencycuron {1-(4-chlorobenzyl) cyclopentyl-3-phenylurea} in soils were investigated under laboratory and field conditions to in order to assess the safety use and environmental impact. In the adsorption rate experiments, a significant power function of relation was found between the adsorbed amount of pencycuron and the shaking time. Within one hour following the shaking, the adsorption amounts in the SCL and the SiCL were 60 and 65% of the maximum adsorption amounts, respectively. The adsorption reached a quasi-equilibrium 12 hours after shaking. The adsorption isotherms followed the Freundlich equation. The coefficient (1/n) indicating adsorption strength and degree of nonlinearity was 1.45 for SCL and 1.68 to SiCL. The adsorption coefficients ($K_d$) were 2.31 for SCL and 2.92 to SiCL, and the organic carbon partition coefficient, $K_{oc}$, was 292.9 in SCL and 200.5 inSiCL. In the laboratory study, the degradation rate of pencycuron in soils followed a first-order kinetic model. The degradation rate was greatly affected by soil temperature. As soil incubation temperature was increased from 12 to $28^{\circ}C$, the residual half life was decreased from 95 to 20 days. Arrhenius activation energy was 57.8 kJ $mol^{-1}$. Furthermore, the soil moisture content affected the degradation rate. The half life in soil with 30 to 70% of field moisture capacity was ranged from 21 to 38 days. The moisture dependence coefficient, B value in the empirical equation was 0.65. In field experiments, the half-life were 26 and 23 days, respectively. The duration for period of 90% degradation was 57 days. The difference between SCL and SiCL soils varied to pencycuron degradation rates were very limited, particularly under the field conditions, even though the characteristics of both soils are varied.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.258-266
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• 2023

This study analyzed methodologies for estimating carbon stocks of perennial woody crops and the research cases in overseas countries. As a result, we found that Australia, Bulgaria, Canada, and Japan are using the stock-difference method, while Austria, Denmark, and Germany are estimating the change in the carbon stock based on the gain-loss method. In some overseas countries, the researches were conducted on estimating the carbon stock change using image data as tier 3 phase beyond the research developing country-specific factors as tier 2 phase. In South Korea, convergence studies as the third stage were conducted in forestry field, but advanced research in the agricultural field is at the beginning stage. Based on these results, we suggest directions for the following four future researches: 1) securing national-specific factors related to emissions and removals in the agricultural field through the development of allometric equation and carbon conversion factors for perennial woody crops to improve the completeness of emission and removals statistics, 2) implementing policy studies on the cultivation area calculation refinement with fruit tree-biomass-based maturity, 3) developing a more advanced estimation technique for perennial woody crops in the agricultural sector using allometric equation and remote sensing techniques based on the agricultural and forestry satellite scheduled to be launched in 2025, and to establish a matrix and monitoring system for perennial woody crop cultivation areas in the agricultural sector, Lastly, 4) estimating soil carbon stocks change, which is currently estimated by treating all agricultural areas as one, by sub-land classification to implement a dynamic carbon cycle model. This study suggests a detailed guideline and advanced methods of carbon stock change calculation for perennial woody crops, which supports 2050 Carbon Neutral Strategy of Ministry of Agriculture, Food, and Rural Affairs and activate related research in agricultural sector.