• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.675-689
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• 2014

This study applied Ensemble Empirical Mode Decomposition(EEMD), a new methodology to define the timing of spring onset over the Republic of Korea and to examine its spatio-temporal change. Also this study identified the relationship between spring onet timing and some atmospheric variations, and figured out synoptic factors which affect the timing of spring onset. The averaged spring onset timing for the period of 1974-2011 was 11th, March in Republic of Korea. In general, the spring onset timing was later with higher latitude and altitude regions, and it was later in inland regions than in costal ones. The correlation analysis has been carried out to find out the factors which affect spring onset timing, and global annual mean temperature, Arctic Oscillation(AO), Siberian High had a significant correlation with spring onset timing. The multiple regression analysis was conducted with three indices which were related to spring onset timing, and the model explained 64.7%. As a result of multiple regression analysis, the effect of annual mean temperature was the greatest and that of AO was the second. To find out synoptic factors affecting spring onset timing, the synoptic analysis has been carried out. As a result the intensity of meridional circulation represented as the major factor affect spring onset timing.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.455-463
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• 2022

To understand functional changes of forest ecosystems due to climate change, correlation between decomposition rate of leaf litter, an important function of forest ecosystems, and microclimatic factors was analyzed. After 48 months elapsed, percent remaining weight of Quercus mongolica leaf litter was 27.1% in the east aspect and 37.0% in the west aspects. Decay constant of Q. mongolica leaf litter was 0.33 in the east aspect and 0.25 in the west aspect after 48 months elapsed. Initial C/N ratio of Q. mongolica leaf litter was 38.5. After 48 months elapsed, C/N ratio of decomposing Q. mongolica leaf litter decreased to 13.43 in the east aspect and 16.72 in the west aspect. Average air temperature and soil temperature during the investigation period of the research site were 8.2±9.0 and 9.1±9.3 in the east and 8.5±7.4 and 9.3±7.3℃ in the west aspect, respectively, with the west aspect showing higher air and soil temperatures. Soil moisture showed no significant difference between east and west aspects (average soil moisture: 19.4±11.0% vs. 20.5±5.7%). However, as a result of analyzing the correlation between decomposition rate and microclimatic factors, it was found that the decomposition rate and soil moisture has a positive correlation(r=0.426) in the east aspect but not in the west aspect. Our study shows that the correlation between decomposition rate and microclimatic factors can be significantly different depending on the direction of the aspect.

• Journal of the Korean Regional Science Association
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• v.33 no.2
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• pp.3-23
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• 2017

This study aims to understand how human capital is related to the inter-regional wage gap between the capital region and the non-capital region in Korea. We focus more specifically on whether the inter-regional wage gap is due to high levels of human capital in the capital region or due to high returns to human capital in the capital region. The decomposition method based on the unconditional quantile regression was used to examine how the relationship between human capital and the inter-regional wage gap varies along the wage distribution. When first estimating earnings functions from the two regions to apply this decomposition method, we included not only conventional indicators of human capital, such as education and on-the-job training, but also occupational skills including cognitive-interactive skills, technical skills, and physical skills. As a result, other things being equal, a large part of the inter-regional wage gap was explained by the human capital variables. Although the composition effect of the human capital variables existed in all the wage quantiles, the more important factor was the wage structure effect of the human capital variables. In addition, among the various human capital variables, the wage structure effect of years of education was a key factor in explaining the inter-regional wage gap. This study is meaningful in that it shows that the relationship between human capital and the inter-regional wage gap may vary depending on the wage quantiles.

• Environmental and Resource Economics Review
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• v.24 no.1
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• pp.189-224
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• 2015

To meet sectoral emission target by 2020 and prepare for the emission trading scheme from 2015, decomposition analysis of energy consumption and GHG emission is required by 18 subsectors in industry sector where emission targets are established. Log Mean Divisia Index decomposition method was used to analyze factors' effects on energy and emission in the industry sector and by 18 subsectors from 2004 to 2011. Industrial energy consumption was increased due to the production effect and energy intensity effect. However structure effect contributes to the decrease of energy consumption. In terms of emissions (including indirect emission due to electricity consumption) in the industry sector, only structure effect contributed to the emission reduction. Factors' effects by subsectors were different. Cement industry, which is included at Nonmetal shows different results from those of Nonmetal industry and machinery industry, which is a subsector of Fabricated Metal, was also similar. In this regard, we should not apply the policy implications from decomposition analysis of aggregated industry such as Nonmetal or Fabricated Metal to its subsectors uniformly and develop a differentiated policy for each subsector industry.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.463-483
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• 2019

Since 2000, Korea's total fertility rate (TFR) has been different from that of Japan, Germany, and France where irreversible constants do not change easily in the fertility rate increasing or decreasing phase. It also showed a gradual increase from the minimum fertility level 1.08 in 2005 to 1.23 in 2015, which dropped to 1.17 in 2016, to 1.05 in 2017 and to 0.98 in 2018. This is similar to a double dip in the economic status of a recession. This paper investigates such a TFR increase and decrease factor that predicts the number of births affecting TFR, examines trends in the proportion of married and marital fertility rate broken down by TFR decomposition method. We also examined how these changes affect the change in TFR. According to the results, the number of births is estimated to be between 320 and 330 thousand in 2018, 300 thousand in 2020, 230 and 240 thousand in 2025. The proportion of married is steadily decreasing from 1981 to 2025, and the marital fertility rate is predicted to decline until 2002, then increase from 2003 to 2016 and decrease from 2017 to 2025. Finally, the trend of TFR in terms of number of births, TFR decomposition and statistical model is expected to show 0.98 in 2018, 0.93 to 1.11 in 2020 and 0.76 to 1.08 in 2025.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.65-84
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• 2010

The purpose of Inequality Index Decomposition is to know the cause of overall inequality through decomposing aggregate inequality index into relevant components. Previous studies have mostly focused on the absolute contribution meaning that how much each component possesses out of overall inequality. However it could be more important to know the marginal contribution and inequality effect of each component in order to implement policies reducing overall inequality effectively. For this, we decomposed Gini Coefficient as representative inequality index into income sources or social welfare programs and calculated each Gini Income Elasticity(GIE). Analysis result says that regular employee income and employer(or the self-employed) income, of which GIE are 1.205 and 1.867, are classified as inequality-increasing income source. GIE can be one of good methods to analyse the inequality effect of various income sources and social welfare programs.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.289-298
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• 2023

Stored rice grain undergoes physical and chemical deteriorations over time. As temperature and moisture content are important factors affecting to the denaturation of rice, it is important to store rice at a low temperature and hermetic condition. From a microscopic point of view, many studies have already reported how proteins and lipids were denatured within rice grain. Meanwhile, the weight loss of rice is currently observed at actual storage sites and can occur for diverse reasons. In this study, it was assumed that the decomposition process of polysaccharides, known as the main component of rice, plays an important role in its weight loss. In specific, the roles of enzymes were also evaluated. Our interest is in the major polysaccharides within a rice grain such as starch as well as within a rice endosperm cell wall. It is suspected that the weight loss of rice grains during storage seems to associate with the degradation of amylose and amylopectin. Nevertheless, it should be also speculated the correlating effect of other components such as proteins and lipids.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.39-45
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• 2017

The market for lactose-hydrolyzed milk is growing due to an increased awareness of lactose intolerance, and increased market interest for modified milk with health claims. The aim of this study was to compare the quality characteristics of 2% lactose-hydrolyzed milk with its lactose hydrolysis rate, with the goal of applying the method to dairy product monitoring in the future. We observed that the freezing point of milk significantly decreased with increasing lactose hydrolysis rate. A linear relationship was found between lactose concentration and freezing point, following the equation (y=-50.416x + 767.91). However, no significant changes were observed in other physicochemical properties of the milk (pH, titratable acidity, total solids and color) (p<0.05). In conclusion, we could predict the residual lactose content quickly and easily in 2% low fat milk by measuring its freezing point. This could represent an easy means for assessing the lactose hydrolysis rate of dairy products.

• Journal of The Korean Association For Science Education
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• v.23 no.6
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• pp.660-670
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• 2003

This study examined the conceptions of high school students, In-service chemistry teachers, and chemistry teachers related to the electrolysis phenomena by questionnaires and follow-up interviews. High school chemistry II textbooks were analyzed for finding the cause of the misconceptions of the teachers and students. From the analysis, it was found that many teachers represented to students the reduction-oxidation reaction and the electrodes of electrolysis are opposite to the reaction of a chemical cell without explanation of the principles. It means that students would learn the electrolysis phenomena by rote. But the teachers thought that it was not necessary to explain the principles to students because the students could not understand. Also, some of the teacher had misconceptions in electrolysis of solution taking no account of water electrolysis. They only considered the reduction-oxidation reactions of the ions already were contained in solution. They did not considered the ions generated by the electrolysis. This tendency is similar to In-service chemistry teachers and high school students. Also, this tendency can be found in chemistry II textbooks.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.305-310
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• 1998

Glucosidic bond at the $C_{20}$ position of the sapogenins was hydrolyzed easily in the lower pH, higher temperature and longer time to give prosapogenins and sugars. The glucosidic bond of saponin at the $C_3\;of\; ginsenoside-Rb_1\;$, which is secondary carbon, was relatively stable due to the low electron density of -0.2. But the bond of saponin at the $C_{20}$ position, which is tertiary carbon with the relatively high electron density of -0.3, was liable to be hydrolyzed even in weak acidic solution by the increase of heating time. On the other hand, fresh and white ginseng contained 4.12 mg/g, 13.05 mg/g of citric acid, 0.68 mg/g, 2.18 mg/g of malonic acid, 1.13 mg/g, 3.68 mg/g of oxalic acid, 2.68 mg/g, 8.62 mg/g of malic acid and 0.13 mg/g, 0.46 mg/g of succinic acid, respectively. Ginseng saponins were very stable in ginseng extract neutralized with sodium carbonate or sodium bicarbonate corresponding to the equivalent amount of the total organic acid in the ginseng.