• Korean Journal of Social Welfare Studies
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• v.40 no.3
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• pp.377-406
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• 2009

This study used laten class growth analysis to identify discrete developmental patterns of delinquent behaviors in adolescence. This present article also examined associations among these trajectories to determine how the development of delinquent behaviors relates to protective and risk factors, which include parental monitoring, attachment with parent, association with deviant peers, self-control, and negative stigma from others. Four-wave panel data from a Korea Youth Panel Study were used for the latent class growth model analysis. The sample consisted of 3,446 adolescents who were assessed at 4 measurement waves with approximately 1-year interval. Four trajectories of delinquent behaviors emerged: delinquency persistence, delinquency increaser, delinquency decreaser, normative group(almost no delinquent behaviors). Association with deviant peers had the most proximal strong influence on the probability of being in the delinquency increaser and delinquency persistence group compared, noed to the normative group. Parental monitoring, self-efficacy and negative stigma also differentiated the four delinquent behavior trajectories from one another after controllig for socio-demographic variables. The study suggested that there is a significant heterogeneity in the timing and change rate of delinquency progression. Adolescent delinquency prevention and intervention programs will need to consider this heterogeneity and enhance attention to protective and risk factors depending on the subpopulation.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.507-515
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• 2021

Objectives: The aim of this study was to evaluate the extent of the potential erosion of enamel induced by three different types of commercial fermented milk using the pH cycle model. Methods: Specimens were treated and soaked up in three types of fermented milk and in mineral water for 10 min, four times a day for 8 days, and all of the specimens were immersed in artificial saliva outside of treatment times. The microhardness of the surface was measured by a microhardness tester, and a scanning electron microscope (SEM) was used to identify the enamel surface morphology. Results: The differences in the surface microhardness (ΔVHN) of enamel were different among the groups (p<0.05). The four groups were in descending order of ΔVHN: the liquid type group, condensed-drink type group, condensed-stirred type group, and control group. The liquid type group had a higher ΔVHN than the other two fermented milk groups (p<0.05). Based on SEM observation, the most severe surface damage was due to the liquid type of fermented milk. Conclusions: Customers' careful discretion is advised when purchasing these types of fermented milk. This information is anticipated to be of much value in the prevention of dental erosion.

• Journal of Korea Trade
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• v.23 no.6
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• pp.66-92
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• 2019

Purpose - Foreign Exchange Rates (FER) have been one of the most significant factors for both Korean exporters and the economy of Korea. The purpose of this study is to evaluate whether exporters with a high level of Exchange Rate Elasticity of Sales (ERES) make the use of earnings management for Income Smoothing (IS). Design/methodology - Income smoothing was obtained using the methodology suggested by Leuz, Nanda and Wysocki (2003). Accruals-based Earnings Management (AEM) was estimated using Discretionary Accruals (DA) calculated by the operant Jones Model developed by Dechow, Sloan and Sweeney (1995). Real Earnings Management (REM) was obtained using the methodologies suggested by Roychowdhury (2006) and Cohen and Zarowin (2010). Data were 2,402 firm years of public listed companies on the KRX, which were not in the financial industry and had a settlement of accounts in December for the period from 2013 to 2017. Findings - Results of the evaluation are as follows. First, companies with higher levels of ERES have relatively lower levels of smoothing of reported income. This might be because a fluctuation in sales caused by an exchange rate fluctuation has a direct impact on the volatility of the reported income. Second, companies with high levels of both ERES and IS have a positive correlation with both AEM and REM. This might be because companies with high levels of IS engage in earnings management to smooth reported income. Specifically, it is possible to assume that for smoothing the reported income, not only AEM but also REM is practiced. Third, companies with high levels of ERES but low levels of IS have a negative correlation with both AEM and REM. This could be interpreted as companies exhibiting low levels of IS due to higher levels of ERES tend to control IS. In addition, such results were supported by firms relying highly on exporting, and are consequently sensitive to exchange rate fluctuation. Therefore, it may conclude that companies with high levels of ERES make the use of earnings management as a means of IS. Originality/value - This study can find its significance from the fact that it is the first study, empirically verifying that companies of Korea, where exportation is a large part, use both AEM and REM as a means for smoothing reported income upon facing exchange rate fluctuations. In addition, it is highly expected that the results of this study could be useful for participants of financial markets when making IS-related decisions.

• Food Engineering Progress
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• v.15 no.4
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• pp.376-381
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• 2011

The baking performance of Cudrania tricuspidata leaf powder as a value-added food ingredient was investigated in a model system of sponge cakes. Cudrania tricuspidata leaf powder was incorporated into cake batter at 5 levels (0, 5, 10, 15, and 20%, w/w) by adding equivalent amount based on total weight of wheat flour. The specific volume, height, moisture content, volume index, and symmetry index of sponge cakes decreased significantly with the increase in Cudrania tricuspidata leaf powder content (p < 0.05). Sponge cakes became darker and firmer with increase in Cudrania tricuspidata leaf powder content (p < 0.05), as indicated by decrease in the $L^*$ and increase in the firmness measured by the texture measuring instrument. Total polyphenol content also increased gradually as the Cudrania tricuspidata leaf powder content increased. Finally, the consumer acceptance test indicated that addition of Cudrania tricuspidata leaf powder up to 10% in the formulation of sponge cakes did not significantly influence the consumers' acceptability with respect to taste and flavor. In addition, the overall acceptability was not different from each other for control and 5% sample (p > 0.05).

• Journal of Animal Science and Technology
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• v.61 no.2
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• pp.55-60
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• 2019

Colibacillosis is one of the major health problems in young piglets resulting in poor health and death caused by Escherichia coli producing F18 pili and Shiga toxin 2e. It is pivotal to reduce colibacillosis in weaned piglets to enhance production performance. In this study, we evaluated synbiotics as the gut health improvement agents in the mouse model challenged with Shiga toxin-producing E. coli (STEC) isolated from piglets. Prebiotic lactulose was formulated with each $5.0{\times}10^6CFU/mL$ of Pediococcus acidilactici GB-U15, Lactobacillus plantarum GB-U17, and Lactobacillus plantarum GB 1-3 to produce 3 combinations of synbiotics. A total of 40 three weeks old BALB/c mice were randomly assigned to 4 groups (n = 10): a control group and 3 synbiotics treated groups. Each treatment groups were daily administrated with $5.0{\times}10^6CFU/mL$ of one synbiotics for the first week, and every 3 days during the second week. All the mice were challenged with $8.0{\times}10^8CFU/mL$ of STEC 5 days after animals began to receive synbiotics. Mice treated with synbiotics based on Pediococcus acidilactici GB-U15 and Lactobacillus plantarum GB-U17 significantly improved daily weight gain compared to mice in other groups. While mice treated with GB-U15 showed better fecal index, no significant differences were observed among groups. Gross lesion and histopathological evaluations showed that mice treated with GB-U15 moderately improved recovery from STEC infection. In conclusion, our results suggest that the synbiotics formulated with lactulose and Pediococcus acidilactici GB-U15 have potential benefits to prevent and improve colibacillosis in weaned piglets.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.376-385
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• 2018

To estimate the hourly temperature distribution due to solar radiation during the day, on slope in complex terrain, an empirical formula was developed including the hourly deviation in the observed temperature following solar radiation deviation, at weather stations on the east-facing and west-facing slopes. The solar radiation effect was simulated using the empirical formula to estimate hourly temperature at 11 weather observation sites in mountainous agricultural areas, and the result was verified for the period from January 2015 to December 2017. When the estimated temperature was compared with the control, only considering temperature lapse rate, it was found that the tendency to underestimate the temperature from 9 am to 3 pm was reduced with the use of an empirical formula in the form of linear expression; consequently, the estimation error was reduced as well. However, for the time from 5 pm to 6 pm, the estimation error was smaller when a hyperbolic equation drawn from the deviation in solar radiation on the slope, which was calculated based on geometric conditions, was used instead of observed values. The reliability of estimating the daytime temperature at 3 pm was compared with existing estimation model proposed in other studies; the estimation error could be mitigated up to an ME (mean error) of $-0.28^{\circ}C$ and RMSE (root mean square error) of $1.29^{\circ}C$ compared to the estimation error in previous models (ME $-1.20^{\circ}C$, RMSE $2.01^{\circ}C$).

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.141-151
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• 2019

Korea has passed the Act on the Integrated Control of Pollutant-Discharging Facilities in 2015, and the integrated environmental management under the BAT standard is underway. To summarize the nature of integrated environmental management, it is the regulation by the integration of the management of the multi-pollutant source and the technical standard of BATs. In general, in environmental economics, regulation-based on technical standards are known to be inefficient. This paper attempts to evaluate the efficiency of BAT standards from an economic point of view. A simple multi-pollutant model demonstrates that the inefficiency of the environmental tax with imperfect information in a single pollutant situation is amplified under multi-pollutant conditions. The simultaneous introduction of BAT and IPPC can be partially explained by this logic. It is also highlighted by the strengthening of BAT standards by EU, as a countermeasure to the potential deterioration of air quality caused by the change of effective environmental taxes accompanying the fuel and emission price changes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.709-719
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• 2021

Recent progress in analysis and flight simulation methods enables wider use of a virtual certification and reduces number of certification flight tests. Aerodynamic database (AeroDB) is one of the most important components for the flight simulation. It is composed of aerodynamic coefficients at a range of flight conditions and control deflections. This paper proposes and efficient method for construction of AeroDB that combines Gaussian Process based Variable Fidelity Modeling with adaptive sampling algorithm. A case study of virtual certification of a F-16 fighter is presented. Four AeroDB were constructed using different number and distribution of high-fidelity data points. The constructed database is then used to simulate gliding, short pitch, and roll response. Compliance with certification regulations is then checked. The case study demonstrates that the proposed method can significantly reduce number of high-fidelity data points while maintaining high accuracy of the simulation.

• The Journal of Korean Philosophical History
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• no.41
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• pp.9-38
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• 2014

Hanhweon-dang Kim Goeng-pil(1454~1504) sublimated ethics whose lead was opened up by Jeong Mong-ju in late Goryeo as one scholarly tendency. Kim Goeng-pil was called 'the father of ethics in Joseon' and has been respected as a model of ethicist for 400 years since then. Following Kim Goeng-pil, Confucian scholars of Joseon cultivated perseverance through Xiaoxue and the perseverance was sublimated to Confucian scholars' energy and then that of state, which served as driving force to keep the national legacy. Kim Goeng-pil suggested how to study with Xiaoxue and sought moral human beings and ethically ideal societies based on strong practicability which is required in Xiaoxue. Individuals' cultivation and social reform are not at a different dimension. Spirit of 'self-cultivation' that Kim Goeng-pil himself demonstrated advanced to pursuit of ethical, ideal state when reaching a level of Jo Kwang-jo. Kim Goeng-pil thought that teaching in Xiaoxue could be achieved through 'Gyeong (敬, respect).' It is the key of Neo-Confucianism in Joseon to control one's mind through the cultivating method of 'Gyeong.' Kim Goeng-pil settled Joseon's Confucianism as 'practical ethics(心學).' Before Kim Goeng-pil, no scholars had well presented the aspects of practical ethics. After King Myeongjong and Seonjo, Confucianism in Joseon worked as the cornerstone of practical ethics. Since mid-17th century, the system of practical ethics had been firmly established with focus on 'Gyeong. Literary men of Kim Goeng-pil and scholars they fostered led the academic and political world of Joseon after mid-16th century. They played the lead in Sarim faction's(士林派) ruling after King Seonjo came to throne. The very foundation which sublimated Joseon to the ethically ideal state and made the Dynasty a 'state of Sarim' was actually laid by Kim Goeng-pil.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.237-268
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• 2021

As variable renewable sources rapidly increase due to the Energy Transition plan, integration cost of renewable sources to the power system is rising sharply. The increase in variable renewable energy reduces the capacity factor of existing traditional power capacity, and this undermines the efficiency of the overall power supply, and demand resources are drawing attention as a solution. In this study, we analyzed how much electric vehicle demand resouces, which has great potential among other demand resources, can reduce power supply costs if it is used as a flexible resource for renewable generation. As a methodology, a stochastic form of power system optimization model that can effectively reflect the volatile characteristics of renewable generation is used to analyze the cost induced by renewable energy and the benefits offered by electric vehicle demand resources. The result shows that virtual power plant-based direct control method has higher benefits than the time-of-use tariff, and the higher the proportion of renewable energy is in the power system, the higher the benefits of electric vehicle demand resources are. The net benefit after considering commission fee for aggregators and battery wear-and-tear costs was estimated as 67% to 85% of monthly average fuel cost under virtual power plant with V2G capability, and this shows that a sufficient incentive for market participation can be offered when a rate system is applied in which these net benefits of demand resources are effectively distributed to consumers.