• Journal of Korea Water Resources Association
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• v.31 no.1
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• pp.3-12
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• 1998

Rainfall intensity under storms affects peak discharge or its time of occurrence in watershed runoff. Thus, it is reasonable to reflect the effect on the parameters of rainfall-runoff models or the governing equations of the models. This paper relates the change of the runoff coefficient of the first tank in tank model to rainfall intensity under storms. The standard four tanks have made the basic structure of the flood event model. and its modifications are as follows: it has two equal runoff coefficients in the first tank: the runoffs from first and second tanks produce delayed response through a simple delaying parameter. Applying the event simulation model to flood data from Naerinchon. runoff coefficients were estimated and their relation to rainfall intensity was analyzed. The results showed the Weak relation of the two factors. The trend of the two was fitted with the equation a1=kI$. where a1is the runoff coefficient of the first tank: I is rainfall intensity; k and m are fitting coefficients. In the verification. the model used moving averages for the calculation of I(t). If the value I(t) gave more greater value of a1(t) than that of previous time(t-1). the flood simulation was performed again from the beginning with the updated greater value of a1. The reflection of rainfall intensity on the runoff coefficient showed far better results than that of a fixed parameter.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.307-316
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• 2019

In the agricultural sector, greenhouse gas emissions vary depending on the interaction of all ecosystem changes such as soil environment, weather environment, crop growth, and anthropogenic farming activities. Agricultural sector greenhouse gas emissions resulting from many of these interactions are highly variable. Uncertainty-based evaluation that defines the interval with confidence level of greenhouse gas emission and absorption is necessary to take account of the variance characteristics of individual emissions, but research on uncertainty evaluation method is insufficient. This study aims to decide on the effect of reducing N₂O emissions from upland soils using an uncertainty-based approach. An uncertainty-based approach confirmed whether there was a difference between confidence intervals in the 5 different fertilizer treatment groups to reduce greenhouse gas emissions. Unlike the statistically significant test with three repetition averages, the uncertainty-based approach method estimated in this study is able to estimate the confidence interval considering the distribution characteristics of the emissions, such as the dispersion characteristics of individual emissions. Therefore, it is considered that the reliability of emissions can be improved by statistically testing the variance characteristics of emissions such as the uncertainty-based approach. It is hoped that the direction of the uncertainty-based approach for the effect of reducing greenhouse gas emissions in agriculture will be helpful in the future development of agricultural greenhouse gas emission reduction technology, adaptation to climate change, and further development of sustainable eco-social system.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.787-796
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• 2012

The aim of this study is to closely examine the changes in their metabolic syndrome index and autonomic nerve systems after the 16-weeks's combined exercise program is carried out on low-level physical strength group (PAPS 4-5 level students). They were divided into two groups; exercise training group (15) and control group (15). This program consisted of five-times-a-week's warm-ups, main activities and warm-downs and it takes 50 minutes per trial. Through SPSS 19.0, all averages and standard deviations of dependent variables were calculated. We first performed Shapiro-Wilk's normality test of the variables. Before verifying the effect of combined exercise program, we tested the equality of means of the variables between combined-exercise-programmed-group and control group through a two-sample t-test and carried out a paired t-test to check if the changes in the variables of two groups before and after 16 weeks are statistically significant. Every statistical test is performed at a significance level of ${\alpha}$=.05. The results are as follows. When it came to metabolic syndrome index, there were statistically meaningful changes in waist measurement, triglyceride, glucose with empty stomach and HDL-C. Also, when it came to autonomic nerve system, there were meaningful changes in all variables. Consequently, it seems that the 16-weeks combined exercise program has positive effects on low level physical strength students.

• Korea journal of population studies
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• v.11 no.1
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• pp.146-158
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• 1988

In order to examine differential mortality, the life tables for the insured persons in national pension scheme were estimated by sex and types of coverage(the insured in workplaces vs. the insured in rural areas). The averages of 1994-1996 data are used for insured in workplaces, but 1996 data are used for insured in rural areas. Life expectancies at the age of 18 are 59.5 years and 67.2 years each for insured males and females and thus 7.7 years longer for females than males in workplaces. Sex difference in mortality reduces as age increases, and more rapidly at younger ages than old ages. For insured in rural areas, life expectancies at the age of 18 are 51.4 years and 61.1 years each for insured males and females and thus sex difference is 9.7 years. The greater sex difference in mortality in rural areas can be explained by sex selective migration. The difference of life expectancy between insured in workplaces and insured in rural areas is 8.1 years for males, and 6.1 years for females. Because rural-urban difference in educational attainment is greater for males than females, the greater difference in life expectancy is observed for males than females.

• Korean Journal of Comparative Education
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• v.28 no.3
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• pp.291-307
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• 2018

As the value of lifelong learning becomes important, states are making efforts to build a system of lifelong learning. According to this tendency, this paper intends to compare the participation rate of lifelong learning, learning outcomes, learning support infrastructure, support of learning expenses, and recognition of lifelong learning. For the comparative pedagogical approach, Bray and Thomas' cubes such as geographical / regional level, non - geographical demographic statistics, social and educational aspects were utilized. The participation rate of lifelong learning in Korea is 34.4% in 2017, which is lower than the OECD average of 46%. The competency scores of Korean adults were lower than the OECD national averages of the PIAAC survey which measured adult competence, language ability, numeracy, and computer-based problem solving ability. In order to recognize prior learning, EU countries have developed EQFs to evaluate all non-formal and informal learning outcomes, while Korea recognizes qualification as a credit banking credit under the academic credit banking system. International comparisons of lifelong learning can be used as an important tool for diagnosing the actual conditions of lifelong learning in a country and establishing future lifelong learning policies. Therefore, it is necessary to maintain that the comparative pedagogical approach of lifelong learning differs according to the historical context, socioeconomic characteristics, and population dynamics, including the formation process and characteristics of modern countries.

• Journal of Korean Elementary Science Education
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• v.40 no.4
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• pp.520-544
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• 2021

This study aims to develop a scientific creativity test for exploring the relationship between elementary students' creative process and product. For this, the researcher reviewed the literatures of scientific creativity and developed the items based on the constructs of creative process and product. After a review conducted by nine science education specialists, a pilot test, and additional revision and supplementation of observation test, the test, consisting of two sets-"animals" and "plants"-was finally conducted on 105 fifth-grade students. The test results were analyzed by using statistical analysis software. WinSteps, SPSS, and AMOS. The main findings from this study are as follows. First, when it comes to scientific creativity, creative process consists of science knowledge, inquiry skills, and creative thinking skills (divergent, convergent, and associative thinking skills). Creative product in science is a new and scientifically useful idea realized in a certain form. Second, observation, which was selected as a representative inquiry skill in this research, should not be related to creative thinking skills. Third, among the rest of the items, usefulness had the lowest averages, as it was, perhaps, difficult to satisfy the teachers' criteria for the scientific validity and usefulness. Fourth, the Spearman correlation coefficients between the items of "animals" and "plants" to find out the parallel-form reliability were significant, except for the item of originality. Fifth, the test was satisfactory with regard to the three aspects of construct validity-convergent, discriminant, and nomological. This study concludes by discussing the usefulness of this test, which has the possibility of exploring the relationship between creative process and product and of playing a role as an authentic evaluation tool in school.

• Journal of the Korea Society of Computer and Information
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• v.28 no.3
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• pp.167-175
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• 2023

In the context of COVID-19, this study was conducted to study how college students' earned grades and average grade point averages changed according to face-to-face and non-face-to-face classes. For this study, grade data was extracted using an access database. For the study, 152 students during the 3rd semester were compared and analyzed the grade point average, average grade point average, midterm exam, final exam, assignment score, and attendance score of students who participated in non-face-to-face and face-to-face classes. As an analysis method, independent sample t-test statistical processing was performed. It was concluded that the face-to-face class students had better grades and average GPA. As a result, the face-to-face class students showed 4.39 points higher than the non-face-to-face class students, and the average grade value was 0.6642 points higher. As a result of the comparative analysis, it was statistically significant, and the face-to-face class averaged 21.22 and the non-face-to-face class had 16.83 points. In conclusion, it was confirmed that face-to-face students' grades were generally higher than those of non-face-to-face students, and that face-to-face students showed higher participation in class.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.247-250
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• 2011

The objective of this study was to find out candidate genes associated with litter size trait in pigs of inbred Large Yorkshire and Landrace populations. 86 sows were screened for candidate genotypes along with litter size data recordings. Association of litter size with genotypes of candidate genes were investigated to verify the usefulness of each gene's genotypes as markers for the trait. For the lines of Large Yorkshire, PRLR3 and RBP4 genes were genotyped. Frequency distribution of PRLR3 with genotypes AA, AB and BB were each 0.14, 0.44 and 0.42. And the average litter size by PRLR3 genotypes were 8.83, 10.81 and 10.70 piglets per litter, the average estimated breeding values of which were 0.243, 0.332, 0.365, respectively for AA, AB and BB genotypes. Genotypic frequencies of RBP4 by AA, AB and BB genotypes were 0.10, 0.44 and 0.46. The average litter size by genotypes of RBP4 were 10.40, 10.57 and 10.35 piglets per litter and their corresponding average estimated breeding values were 0.451, 0.353 and 0.261, respectively for genotypes AA, AB and BB. Significance in differences among genotypes were not observed, but B allele of RBP4 seems to be associated with litter size. In Landrace lines, frequencies of RBP4 genotypes, AA, AB and BB were 0.29, 0.55 and 0.16. And the average litter size of these genotypes were 10.50, 11.08 and 11.00 piglets per litter. The corresponding averages of estimated breeding values of each genotypes were 0.172, 0.135 and 0.104. In Landrace lines, allele A was more likely to be associated with litter size, even if differences among average litter size were not significant. We conclude that genotyping of two candidate genes is a helpful tool to identify genetic potentials of litter size in pigs.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.454-459
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• 2009

The secondary growth of garlic depreciates the quality of a bulb and, in the worse cases, makes it difficult to be used as a seed bulb due to many insertions of small cloves in the seed bulb. Therefore, the effect of soil temperature, seedtime, and fertilization rate on the secondary growth of the big bulbils of Namdo garlic has been examined. When we analyzed into the growth characteristics of big bulbils of Namdo garlic under different fertilizer application levels (50% increased fertilization, experimental fertilization and 50% decreased fertilization), the plant height, numbers of leaf, sheathe diameter, leaf length, and leaf width were the best in 50% increase of the test rate of fertilizer. The occurrence rates of secondary growth were 34.2% in 50% decrease of the test rate of fertilizer, 44.3% in the test rate, and 54.1% in 50% increase of the test rate of fertilizer. In other words, the occurrence rate of secondary growth increased by increasing the fertilization rate. While the average harvested bulb weight were 34.1g in 50% decrease of the test rate of fertilizer, 35.1g in the test rate of fertilizer, and 33.9g in 50% increase of the test rate of fertilizer, there were no changes in the number of cloves under different fertilization rates. As the correlation diagram between the soil temperature and occurrence of the secondary growth showed very high relation with 0.892~0.997, the secondary growth in cultivation of Namdo garlic big bulbils had considerably close correlation with the soil temperature. As the earlier the seedtime was, the growth of the above-groundparts including the plant height, numbers of leaf, and sheath diameter were the better. The averages of bulb weight were 36g in the mid September sowed seed bulb, 29.6g in the late September sowed seed bulb, and 27.9g in the early October sowed seed bulb. Overall, our results showed that the bulb size is dependent on the seedtime and the seedtime has no particular effects on the secondary growth.

• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.157-164
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• 1992

Changes in the both inward current and conductance of membrane by the fertilization were observed using the one microelectrode voltage clamp(or switch clamp) technique. Unfertilized eggs and both 1- and 2-cell stage eggs after fertilization were donated from the superovulated mouse (ICR, more than 6 weeks old) treated with PMSG(pregnant mare serum gonadotropin, Sigma) and HCG(human chorionic gonadotropin, Sigma) and naturally mated ones, respectively in this experiment. Membrane potential was held at -90mV and the voltage step was applied from -80mV to 50mV with interval of 10mV or 20mV for 300ms. since both of amplitudes and time courses in the membrane currents were various according to the states of cells and clamping condition, results were presented by their $averages{\pm}SEM$(standard mean error)and ratios or percentages. Inward currents began to appear in response to the step depolarization from -60mV and reached its maximum at -50mV. However, since the potential was not clamped evenly during the voltage step, current-voltage(I-V) relationship might be positively shifted 10 or 20mV. From the steady-state currents plotted in the I-V curve, outward rectification was markedly observed. Peak inward currents$(i_{in})$ at -50mV were $-0.62{\pm}0.23nA$(n=4),$-0.52{\pm}0.25nA$(n=5) and $-0.37{\pm}0.25nA$(n=6), in the 1-cell stage, 2-cell stage fertilized eggs and in the unfertilized eggs, respectively. Pure inward current (difference between steady-state and peak, $i_{in. pure}$) were $-1.01{\pm}0.23nA$, $-0.69{\pm}0.43nA$ and $-0.68{\pm}0.29nA$, respectively in the 1-cell stage fertilized eggs, unfertilized eggs and 2-cell stage fertilized eggs. These results suggested that the outward current in fertilized eggs of 2-cell stage was more increased than those in the unfertilized eggs. Pure inward currents in the all stages of eggs showed a similar fashion in the I-V relationship from -50mV to 50mV and reversal potential at 50mV. Time constant of inactivation$({\tau})$ in the inward current was decreased as the membrane potential was depolarized in the unfertilized and 2-cell stage eggs but in the 1-cell stage eggs t was not likely to be affected significantly. Slope conductances were 14.2nS, 8.9n5 and 7.7nS in the 1-cell, 2-cell stage fertilized eggs and the unfertilized eggs, respectively. Membranes between two cells within a zona pellucida seem to be electrical-connected in the 2-cell stage eggs from the observation made in the analysis for the electronic spread and decay to the current stimuli. Both of inward current and membrane conductance were increased after fertilization in the mouse eggs. Inward current seems to be carried by the same ion or through the same channels up to the 2-cell stage and ion that carried inward current was thought to play important function after fertilization in the mouse eggs.