• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.127-144
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• 2021

The purpose of this study is to derive service factors based on the "Rail Statistical Yearbook" data of railroad service providers from 1990 to 2019, and to analyze the effect of the service factors on the operating profit ratio(OPR), a representative management performance variable of railroad transport service providers. In particular, it has academic significance in terms of empirical research to evaluate whether the management innovation of the KoRail has changed in line with the purpose of establishing the corporation by dividing the research period into the first period (1990-2003) and the latter (2004-2019). The contents of this study investigated previous studies on the quality of railway passenger transportation service and analyzed the contents of government presentation data related to the management performance evaluation of the KoRail. As an empirical analysis model, a research model was constructed using OPR as a dependent variable and service factor variables of infrastructure, economy, safety, connectivity, and business diversity as explanatory variables based on the operation and management activity information during the analysis period 30 years. On the results of research analysis, OPR is that the infrastructure factor is improved by structural reform or efficiency improvement. And economic factors are the fact that operating profit ratio improves by reducing costs. The safety factor did not reveal the significant explanatory power of the regression coefficient, but the sign of influence was the same as the prediction. Connectivity factor reveals a influence on differences between first period and latter, but OPR impact direction is changed from negative in before to positive in late. This is an evironment in which connectivity is actually realized in later period. On diversity factor, there is no effect of investment share in subsidiaries and government subsidies on OPR.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.346-362
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• 2021

A sediment control dam is an artificial structure built to prolong sedimentation in the main dam by reducing the inflow of suspended solids. These dams can affect changes in dissolved organic matter (DOM) in the water body by changing the river flow regime. The main DOM component for Yeongju Dam sediment control of the Naeseongcheon River was analyzed through 3D excitation-emission matrix (EEM) and parallel factor (PARAFAC) analyses. As a result, four humic-like components (C1~C3, C5), and three proteins, tryptophan-like components (C2, C6~C7) were detected. Among DOM components, humic-like components (autochthonous: C1, allochthonous: C2~C3) were found to be dominant during the sampling period. The total amount of DOM components and the composition ratio of each component did not show a difference for each depth according to the amount of available light (100%, 12%, and 1%). Throughout the study period, the allochthonous organic matter was continuously decomposing and converting into autochthonous organic matter; the DOM indices (fluorescence index, humification index, and freshness index) indicated the dominance of autochthonous organic matter in the river. Considering the relative abundance of cyanobacteria and that the number of bacteria cells and rotifers increased as autochthonous organic matter increased, it was suggested that the algal bloom and consequent activation of the microbial food web was affected by the composition of DOM in the water body. Research on DOM characteristics is important not only for water quality management but also for understanding the cycling of matter through microbial food web activity.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.120-140
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• 2022

Purpose: The purpose of the study was to investigate whether adherence to the Korea Healthy Eating Index (KHEI) was associated with metabolic syndrome and risk markers. Methods: The participants included 8,345 adults, aged 20-59 years, who took part in the 7th Korea National Health and Nutrition Examination Survey (KNHANES). The data were analyzed using a complex-sample t-test, the Rao Scott χ²-test, and logistic regression analysis on the SPSS v. 26.0 software. The participants were divided into four groups by quartiles of KHEI scores. Results: The average KHEI score was 61.06 points out of 100, and the women's score (62.50 points) was significantly higher than that of men (59.63 points). The KHEI quartiles status showed significant differences by age (p < 0.001), household income (p < 0.001), smoking status (p < 0.001), and food security. Specifically, the KHEI quartiles in the men showed significant differences in education (p < 0.001) and economic activity (p < 0.001) whereas those of women showed significant differences in alcohol-consumption (p < 0.001), depression (p < 0.01) and eating-out (p < 0.001). As the KHEI scores increased, the proportion of subjects with an energy intake below the estimated energy requirement (EER) was lower, and significantly better levels of intake were observed for carbohydrate, protein, vitamin C, calcium, vitamin B₁, vitamin B₂, and niacin. The incidence of the metabolic syndrome risk factors, hypertriglyceridemia and hyperglycemia for men and hypertension, and hyperglycemia for women showed significant differences. The KHEI scores were inversely associated with abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, hyperglycemia, hypertension, and metabolic syndrome. Conclusion: Based on these results, we conclude that higher adherence to the KHEI was associated with lower metabolic syndrome risk factors and incidence of the metabolic syndrome.

• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.1-13
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• 2023

The study was carried out to investigate the effects of dietary combined supplementation of antioxidants as catechin and vitamin C on growth performance, meat quality, blood profiles and stress responses of broilers exposed to high temperature. For this experiment, a total of 360 21-day-old male Ross 308 broilers were used. Treatments were assigned with 6 replicates per treatment and 10 birds per replicate in a 2 × 3 factorial design with vitamin C (0, 250 mg/kg) and catechin (0, 600, 1,200 mg/kg). The heat stress environment was maintained at temperature 32±1℃ and relative humidity 60±5% for 24 hours until the end of the experiment. The supplemented antioxidants had no significant difference in weight gain, feed intake and feed conversion ratio (P>0.05). The content of total cholesterol in blood had no interaction, but decrease (P<0.01) in the supplemented catechin group. Also, the supplementation with catechin showed increase in the SOD activity of blood, and lower corticosterone and IgM levels of broilers. The contents of HSP70 and MDA in liver decrease (P<0.05) with the supplementation of antioxidants, and HSP70 showed an interaction between groups. DPPH radical scavenging ability in breast meat increased (P<0.01) in catechin, but meat quality did not show difference according to treatments. Respiratory rate decreased (P<0.05) in catechin, but no interaction with vitamin C. In conclusion, the combination of vitamin C and catechin can alleviate stress under high temperature, such as HSP70 and MDA, but further study on the optimal supplemental level is needed.

• Journal of Science Education
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• v.47 no.2
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• pp.192-210
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• 2023

This study was intended to develop the plant molecular biology experimental program using Rapid-cycling Brassica rapa (RcBr) based on the teaching steps and teaching methods of the cognitive apprenticeship model and to determine its application effects. In order to improve a subject's cognitive function and expertise on molecular biology experiments, two themes composed of a total 8 class sessions were selected: 'Identification of DFR gene in purple RcBr and non-purple RcBr' and 'Identification of RcBr's genetic polymorphism site using the DNA profiling method'. Research subjects were 18 pre-service teaching majors in biology education of H University in Chungbuk, Korea. The effectiveness of the developed program was verified by analyzing the enhancement of 'cognitive function' related to the use of molecular biology knowledge and technology, and the enhancement of 'domain-general metacognitive abilities.' The effect of the developed program was also determined by analyzing the task flow diagram provided. The developed program was effective in improving the cognitive functions of the pre-service teachers on the use of knowledge and technology of molecular biology experiments. It was especially effective to improve the higher cognitive function of pre-service teachers who did not have the previous experience. The developed program also showed a significant improvement in the task of metacognitive knowledge and in the planning, checking, and evaluation of metacognitive regulation, which are sub-elements of domain-general metacognitive abilities. It was found that the developed program's self-test activity could help the pre-service teachers to improve their metacognitive regulation. Therefore, this developed program turned out to be helpful for pre-service teachers to develop core competencies needed for molecular biology experimental classes. If the teaching and learning materials of the developed program could be reconstructed and applied to in-service teachers or high school students, it would be expected to improve their metacognitive abilities.

• Journal of International Area Studies (JIAS)
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• v.14 no.2
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• pp.499-524
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• 2010

The purpose of this study is to based on review of theoretical and empirical studies to assess the independence of central banks - the former Socialist republics, including the Russian Federation and Czech, Poland. In addition, the work is expected to clarify whether a link exists between independence and the most important economic indicators such as inflation, economic activity, the budget deficit. And The subject of this study are the formal and actual independence of national banks, as well as limiting factors: political and economic. Background investigation of the problem of independence of central banks from the fact that, according to many economists, it is essential to the successful development of a market economy. The effectiveness of any country's economy due to currency volatility, low inflation, high reliability of the banking system, etc. As far as the independence of monetary regulation contributes to these goals - one of the most actively debated issues in the world of economic theory and practice for a long time. The issue of central bank independence is extremely important for Russia, Czech, Poland. In the near future to the central bank has important tasks, among which are the transition to inflation targeting in the rejection of significant intervention in the foreign exchange market, as well as improving the sustainability of the national banking system. Transparency and independence of the Bank of Russia, Czech Republic, Poland, in my view, should be an important factor in achieving these goals. The countries of Czech Republic, Poland have already made a number of steps to bring the status of their banks to the European standards. Many other developing countries are also in the process of reforming their central banks and the improving conditions of their functioning. However, despite the fact that as a model for reform used by the central banks of countries with developed market economies, central banks in developing countries are still yet deprived of the legal, economic and political independence. A different situation exists in transition space. Because of significant differences in the views of the authorities in transition republics at the necessary level of independence of central banks and the exchange rate and monetary policy reform of monetary management in these countries led to different results.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.727-736
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• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.1
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• pp.73-94
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• 2023

We carried out the sensitive high resolution ion microprobe (SHRIMP) zircon U-Pb age dating and whole-rock geochemical analysis of granitoids and felsic porphyries in the Ssangyong Valley, Yongchu Valley, and Mungyeong Saejae geosites in the Mungyeong Geopark. The igneous rocks crop out in the western, northwestern and central parts of the Mungyeong city area, respectively, and intruded (meta)sedimentary successions of the Ogcheon Metamorphic Belt, Cambro-Ordovician Mungyeong Group and Jurrasic Daedong Group. The U-Pb isotopic compositions of zircon from two felsic porphyries and one granite samples in the Ssanyeong Valley yielded the Cretaceous intrusion ages of 93.9±3.3 Ma (tσ), 95.1±4.0 Ma (tσ) and 94.4±2.0 Ma (tσ), respectively. On the other hand, a felsic dike sample and a granite in the Yongchu Valley and a porphyritic granite in the Mungyeong Saejae had intrusion ages of 90.2±2.0 Ma (tσ), 91.0±3.0 Ma (tσ) and 88.6±1.5 Ma (tσ), respectively. Based on the average standard error calculated in combination with results of previous studies in this area (Lee et al., 2010; Yi et al., 2014; Aum et al., 2019), the geochronological results show that spatial variation in intrusion age of ~5 Myr between the Ssangyong (94.5±0.2 Ma) and Yongchu Valleys (89.7±0.4 Ma) is apparent. The geochemical compositions of major and trace elements in the samples showed an affinity of typical post-orogenic granite, indicating their petrogenesis during the late stage of Early Cretaceous magmatic activity possibly in association with subduction events of the Izanagi Plate.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.115-124
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• 2022

This study was conducted to obtain basic data that could help prevent damage caused by slow-moving landslides (land-creep). Specifically, the geological, topographic, and physical characteristics of land-creep were analyzed in Jiphyeon-myeon, Jinju-si. The first and second analyzed land-creeps occurred in 1982 and 2019, respectively. The area damaged in the second land-creep was about 11.5-fold larger than that damaged in the first land-creep. The dominant constituent rock in the land-creep area was sedimentary rock, which seems to be weakly resistant to weathering. The areas that collapsed due to land-creep were related to the presence of separated rocks between the bedding plane in the estimated activity surface over the slope direction and the vertically developed joint surface. Thus, surface water and soil debris were introduced through the gaps of separated rocks. Additionally, the areas collapsed due to the combination of the bedding plane and joint surface shale and sandstone showed an onion structure of weathered outcrop from the edge to inner part caused by weathering from ground water. Consequently, core stones were formed. The study area was a typical area of land-creep in a mountain caused by ground water. Land-creep was classified into convex areas of colluvial land-creep. The landslide-risk rating in the study area was classified into three and five classes. The flow of ground water moved to the northeast and coincided with the direction of the collapse. Soil bulk density in the collapsed area was lower than that in ridge area, which was rarely affected by land-creep. Thus, soil bulk density was affected by the soil disturbance in the collapsed area.

• Journal of the Korean Society of Floral Art and Design
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• no.41
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• pp.3-12
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• 2019

The purpose of this study was to investigate the effect of forest play activities on children's emotional vocabulary change. Forest play activities were conducted for 498 children aged 4 to 5 years old who visited the environmental training in G city for forest play activity for 1 hour. As a result, positive vocabulary was significantly improved from 0.95±0.78 before forest play to 1.15±1.21 after forest play(p=.003) and negative vocabulary was significantly decreased from 1.27±1.58 to 0.41±1.10(p=.000). In the case of male children, positive vocabulary was increased significantly from 0.96±0.82 to 1.36±1.24(p=.000), in the case of negative vocabulary, it decreased significantly from 1.42±1.74 to 0.55±1.30(p=.000). In the case of female children, negative vocabulary was significantly decreased from 1.12±1.37 to 0.26±0.26(p=.000), but the positive vocabulary increase was not significant(p=.851). As a result of age, for a 4-year-old children, positive vocabulary did not show significant difference between before and after forest play(p=.471), and negative vocabulary was significantly increased from 1.04 ± 1.42 before forest play to 0.41±1.16 after forest play(p=.000). For a 5-year-old children, positive vocabulary was increased significantly from 0.96±0.85 to 1.23±1.21(p=.001) and negative vocabulary was decreased significantly from 1.41±1.65 to 0.41±1.06(p=.000). As a result of this study, it was found that play activities using various natural objects in the forest were directly related to nature, resulting in positive vocabulary increase and negative vocabulary decrease.