• Journal of the Korean Regional Science Association
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• v.40 no.2
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• pp.91-106
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• 2024

Around the world, many countries experiencing the issue of shrinking cities are continually expanding high-speed rail networks to enhance regional accessibility and address imbalances. This study analyzed the effects of high-speed train operations on the age-specific population migration in South Korean municipalities from 2012 to 2019, taking into account the risk levels of shrinking cities. For this purpose, an analysis was conducted using age-specific net in-migration population as the dependent variable, employing the spatial panel autoregressive model. The research results indicated that the influence of high-speed rail on regional population inflow varies depending on the risk level of shrinking city. In other words, high-speed railway operations had positive effects on population inflow in the capital areas and some major cities, while explained population outflow in the other regions. High-speed railways particularly exerted a significant impact on the inflow of the young and middle-aged population, representing the working age, but this effect was also limited to regions with a low risk of shrinkage. The findings of this study emphasize the importance of considering planned population and industrial attraction when installing high-speed rail with the goal of achieving regional balanced development and mitigating shrinkage. The results of this study also suggest the need for subsequent research to explore factors that positively influence population structure and inflow based on the level of shrinkage risk in each region, as well as the introduction of new policies tailored to the specific situations of each local government.

• Information Systems Review
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• v.19 no.2
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• pp.21-35
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• 2017

The advancement of IT and the "Fourth Industrial Revolution" blurred the boundary between industries. The importance of strategic cooperation between enterprises is emphasized. IT companies must consider their existing business areas and create new territories to drive changes in the industry. They must also secure their competitive edge and manage economic costs to enable them to compete with their global counterparts. By utilizing their resources effectively, these firms can create value through inter-firm cooperation. This study analyzes the collaborative network of global IT companies using social network analysis and examines the effect of this network on firm performance. Collaborative linkages and betweenness centrality, which represent the bridging position of a firm in a network, significantly affect firm performance. This result highlights the importance of the structural position of a firm in a cooperative network of IT companies. This study also characterizes clusters in a network of IT companies. Most of these clusters comprise a combination of IT companies in diverse IT industries. These clusters suggest that these companies engage in multilateral cooperation without boundaries to maximize their business capabilities. This study offers practical implications for establishing a cooperative strategy and framework that can capture business trends in the IT industry from a macroscopic view. This study also visualizes collaborative networks in a multifaceted way using social network analysis to provide researchers and business practitioners with an informative viewpoint.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.77-84
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• 2024

Objectives: Interventions promoting physical exercise and healthy habits in workplaces have been shown to be effective in reducing risk factors for metabolic syndrome. This study was conducted to examine the effects of an individualized conditioning exercise program of IT company office workers with or at higher risk of metabolic syndrome. Methods: A total of 444 IT company office workers with or at higher risk of metabolic syndrome participated in a 3-month conditioning exercise program. Body composition data using bioelectrical impedance analysis and cardiopulmonary data using cardiopulmonary exercise testing from 53 individuals (mean age: 34.8 ± 7.1 years, sex : 21% female, height : 170.4 ± 6.8 cm, weight : 75.2±12.2 kg, body mass index : 25.8±3.3 kg/m²) who have successfully completed pre-test, intervention, and post-test were analyzed. The 12 weeks intervention encompassed: (1) health counseling (2) supervised exercise(endurance-based, aerobic exercise, or circuit training once a week for 50 minutes at heart rate reserve(HRR) of 77-95%) (3) self-directed exercise and biweekly health screening checks. Results: The results indicated a significant decrease in body weight, body fat mass and body mass index, respectively. Moreover, VO₂peak, AT VO₂ and AT Time significantly improved, respectively. Resting blood pressure(SBP/DBP) showed positive changes but were not statistically significant. We observed the correlation between characteristics of participants and rate of changes in cardiopulmonary outcomes of participants, there are no significant correlation. These results indicate positive changes in body composition and cardiorespiratory fitness parameters following individualized conditioning exercise program. Conclusions: Individualized workplace exercise program for preventing metabolic syndrome can lead to improvements in body composition and cardiorespiratory fitness.

• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.321-328
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• 2024

The performance of carbon fluoride-based lithium primary batteries (Li/CF_X) is limited due to poor rate capability resulting from the low conductivity of carbon fluoride, which is used as the active material. Therefore, in this study, we applied a carbon coating using pyrolysis fuel oil on carbon fluoride to overcome this limitation and considered its electrochemical performance. An amorphous carbon layer was formed on the surface of the carbon fluoride through carbon coating, and the surface physicochemical properties of the carbon fluoride were meticulously considered based on the heat treatment temperature. The advanced research chemical 1000 heat treated at 450 ℃ (ARC@C450) sample, which was commercial carbon fluoride heat-treated at 450 ℃, showed the largest increase in the concentration of sp² carbon bonds (62%) and the highest formation of semi-ionic C-F bonds. Also, the primary battery using the ARC@C450 sample as a cathode active material exhibited stable discharge capability at the highest rate of 5 C (392 mAh/g), and the R_ct value was reduced by 53% compared to the untreated sample. Therefore, we proposed pyrolysis fuel oil-based carbon coating as a method to overcome the low conductivity of carbon fluoride, and the carbon-coated carbon fluoride showed excellent rate performance, suggesting its potential application in high-power primary batteries.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.148-153
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• 2010

This study was carried out to investigate the effect of extraction methods on the physicochemical characteristics using seed oil of wild green tea (Camellia sinensis). When the solvent extraction method after grinding and steam treatment (SGS) was used for oil extraction, the yield was highest. The specific gravity was a range of $0.91{\sim}0.94g/cm^{3}$ irrespective of extraction methods of oil. However, the light in the solvent extraction method after grinding (SG), the red in the pressure extraction method after grinding and roasting treatment (PGR), and the yellow in SG method were highest. Among various fatty acids, the concentrations of C16 : 0, C18 : 1 and C18 : 2 were highest, irrespective of extraction methods. Especially, the C16 : 0 concentration was in the order of SG (34.78%), SGS (23.04%), and PRGS method (23.01%), the C18 : 1 concentration was in the order of PGR (43.35%), SGS (42.7%), SG method (39.0%), and in the case of C18 : 2, it was in order of PGR (23.15%), SGS (23.03%), and SG method (15.01%). The saturated fatty acid concentration was in the order of SG (40.59%), PGR (31.61%), and SGS method (30.1%). On the other hand, in the case of the unsaturated fatty acid, it was in the order of SGS (69.9%), PGR (68.39%), and SG method (59.41%). The acid values in the SGS and SG method after 10 days of storage were in the range of 6~8 mgKOH/g. However, in the case of PGR method, it was increased with the increase of storage time and was 49.3 mgKOH/g after 60 days. The peroxide values in the SGS and SG method were in the range of 60~100 mEq/g from 10 to 60 days of storage. On the other hand, when the storage time was increased from 10 to 30 days, it was sharply increased from 60 to 240 mEq/g. The rancidity was in the order of $Fe^{2+}$, $Cu^{2+}$, $Cr^{2+}$, $Zn^{2+}$ and $Ni^{2+}$, irrespective of extraction methods. Especially, when butylated hydroxyanisole (BHA) was added into oil containing 1.0 ppm of <$Fe^{2+}$, the peroxide value was decreased from 539.4 to 216.6%. These results show that seed oil of Camellia sinensis grown in Iksan can be applied as sources for cosmetics, detergents, food, and pharmaceuticals.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.219-225
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• 2007

This study was performed to provide basic ideas as understanding and application for oriental medicinal cuisine (Yak-Sun). To develop medicinal cuisine, it is necessary to grasp the theoretical system. And to develop medicinal cuisine for health enhancement, it is also required not only to consider constitutions but also to suggest the need of knowledge for moderation in terms of regimen along with the theory of oriental medicine. Also to develop medicinal cuisine according to the perspective of oriental medicinal theory, what should be taken into account is not only the understanding of the characteristics of food materials, but also the properties of them that the theory of oriental medicine. Lastly the scientific effect of the medicinal cuisine which is developed according to the oriental medicinal theory. And it is believed to De essential for the government to make effects to set a standard and laws to validate the medicinal effects and the process of assessment so that the systematic development can be encouraged, and to prepare guidance to food development for national health improvement. This research was planned and executed to evaluate how the composition of Yak-sun(oriental diet therapy) can effect health conditions of people who are suffering from diet-related diseases like cardiovascular related disease. by taking Yak-sun in a form of nutritional supplement with our daily meals. We produced Yak-sun tea with Mansam, Hwanggi, Tanggi and Paekchak and observed nutritional composition. We concluded that we could apply the components not only in a form of tea, but also in other forms of various food. The information we received from this conclusion will be a basic information on how we can apply oriental medicinal resources into other food and will also be a steppingstone for medicinal herbs to step foot in the field of functional food research, which already draws sizable attention world-wide.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.339-343
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• 2012

This study was performed to examine the effect of the clay mineral illite on the improvement of soil and plant growth. Red pepper (Capsicum annuum L.) was used as a test vegetable crop. The experiment was performed during six weeks in the plantation of the Chungbuk National University. Its seedlings were cultivated in the soil normally used for horticultural purpose. Among the seedlings germinated the healthy and regular size of seed were selected and cultivated in the plantation. They were treated with two forms of illite, particulate (PA) and powder (PW), at the following application rates: standard application[P1 (PA1, PW1), soil: illite = 1:20 (w/w)] and two times [P2 (PA2, PW2), 1:10 (w/w)] of standard application. Untreatment (P0) was used as a control soil. At six weeks of cultivation, their growth lengths were correspondingly increased as the application rate was increased ranging from P0, P1, and P2. Their growth length was a little greater with the application of powder illite (PW) than with the particulate illite (PA). Based on the plant analysis of root, leaf, and stem of red pepper, the uptake amounts of K, Ca, and Mg, were correspondingly increased, as the application rate was increased ranging from P0, P1, and P2 respectively. At the same application rate, their amounts taken up in the respective parts were higher with the application of PW illite than on the PA one. Especially the amounts of Ca and Mg were higher in the stem and leaf than root. Consequently, it appears that the illite treatment, especially, PW form of illite, enhance the growth of red pepper in the plantation during the six weeks of experiment.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.39-46
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• 1999

This study was performed to examine the effect of initial composition ratio and various reaction conditions on CEC and crystallinity of the product in hydrothermal synthesis of zeolitic materials from fly ash. Na-P1 zeolite was formed from the mixture with $SiO_2/Al_2O_3$ ratio above 2.55, however from the mixture with $SiO_2/Al_2O_3$ ratio below 2.25 hydroxy sodalite was formed. The CEC of reaction product(Na-P1 zeolite) treated with 3N-NaOH, $Na_2O/Al_2O_3$ ratio 2.55 and $SiO_2/Al_2O_3$ ratio 2.0 for 12 hours at $103^{\circ}C$ was about $285cmol^+kg^{-1}$, which was higher than those of the products of other reaction condition. The crystallinity of Na-P1 zeolite as high as 45.1% was attained at the optimum reaction condition of 2N-NaOH, $SiO_2/Al_2O_3$ ratio 2.55, $Na_2O/Al_2O_3$ ratio 1.5 for 12 hours at $103^{\circ}C$. The XRD peak of the reaction product could be measured at 7.16, 5.04, 4.12, 3.18, $2.69{\AA}$ and tetragonal pillar shape observed by SEM image be characteristic for Na-P1 zeolite. Judging from the result, it should be considered the optimum synthesis condition for Na-P1 zeolite from fly ash was 2~3N NaOH, $SiO_2/Al_2O_3$ ratio 2.55 and $Na_2O/Al_2O_3$ ratio 1.5~2.0 for 12 hours at $80{\sim}103^{\circ}C$.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.366-379
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• 2015

Objectives: The objective of this study is to assess airborne particulate matter(PM) pollution and its effect on health of residents living near Ansim Briquette Fuel Complex in Daegu metropolitan region. Methods: The California Puff(CALPUFF) dispersion model, version 5.8, which can estimate the dispersion direction and range of airborn $PM_{10}$ was used to determine the possible areas affected by $PM_{10}$ pollutants emitted from Ansim briquette fuel complex. The CALPUFF modeling with 200 m grid-cell resolution was performed based on $PM_{10}$ emissions estimated from the amount of coal consumption in the fuel complex for four months in 2012. The Weather Research and Forecasting(WRF) fields were processed using CALMET to produce CALPUFF-ready meteorological inputs. Also, the distance from Ansim Briquette Fuel Complex to the residence of each environmental pneumoconiosis patient was analyzed. In addition, the affecting region of the pollutants emitted from briquette factories in Ansim Briquette Fuel Complex was determined. Results: CALPUFF modeling results showed that the highest concentrations of $PM_{10}$ were found near around the fuel complex. The modeled $PM_{10}$ distributions were characterized by significant decreases in concentration with distance from the complex. Seasonally, the highest concentration of $45{\mu}g/m^3$ was calculated in October which was mostly due to the distinct variation of amount of emission. Additional modeling with the maximum $PM_{10}$ emission of about 88 tons per year in 1986 showed that the highest concentration in October was nearly increased by 8 times than the concentration modeled with emission of 2010. As a result of medical examination and interviews for the residents in Ansim Briquette Fuel Complex and its surroundings, 8 environmental pneumoconiosis patients were found. These patients do not have occupational exposure and history. These patients have lived 0.3~1.1 km area in Ansim Briquette Fuel Complex and its surroundings. Conclusions: Airborne particles emitted from Ansim Briquette Fuel Complex can contribute to significant increase in $PM_{10}$ concentration in residential areas near around the complex. Especially, the residents near fuel complex may exposed to the pollutants emitted from the factories in Ansim Briquette Fuel Complex.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.457-465
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• 2009

The characteristics of Holstein colostrum according to the methods that were employed in processing it were analyzed in this study to improve its industrial utilization. Colostrum samples were collected from the dairy farm of the National Institute of Animal Science (NIAS). The milk fat, protein, lactose, and SNF contents of colostrum were 4.34, 6.99, 3.37, and 11.10%, respectively. The effects of spray drying, freeze drying, freezing, acidification, and inoculation of lactic-acid bacteria on the characteristics of colostrum were then compared. The freezing of colostrum was found to be proper for long-term storage in a farm. Freeze-dried colostrum powder could not meet the processing requirements and the component standards for animal products in terms of the total bacterial and coliform bacteria counts, but spray-dried colostrum powder could meet the microbiological requirements because of its bactericidal effect during the spray-dry treatment. The inoculation of lactic-acid bacteria showed a better inhibitory effect on coliform than the acidification treatment, but protein precipitation appeared because of the low pH and the high acidity. To estimate the effects of the processing methods employed on the IgG of colostrum, the IgG contents of the milk treated by long temperature long time (LTLT) ($65^{\circ}C$, 30 min), by inoculating the lactic acid bacteria starter, by spray drying, and by freeze drying were measured. The IgG contents of the colostrum were changed significantly by the processing treatment employed, from 53.98 mg/mLto 33.28, 34.82, 21.98, and 36.89 mg/mL, respectively.