• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.92-97
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• 2011

Landfill is the main treatment method for bottom-ash because it has not only an irregular particle size and ingredients but also not proper recycling treatment. The aim of this study is to raise recycling rate of bottom-ash(nonplasticity pulverulent) and for the purpose of alternatives of clay to investigate the properties of Bottom-ash (B/A)-Hard Clay (H/C) bodies with controlled interfacial chemistry properties. After investigating the sedimentation height of suspensions with controlled pH, it was discovered that there was no hetero-polar aggregation for mixed slips because hard clay and bottom-ash had similar interfacial chemistry properties. Also, bulk density, water absorption, and microstructure properties of each pellet was observed that made by silp casting method and manufactured at $50^{\circ}C$ intervals between $1000{\sim}1250^{\circ}C$. As a result, dispersed slip of clay and bottom ash are possible for slip casting and plastic forming process because they exhibit Bingham plastic behavior. Products that made by slip with dispersed clay and bottom ash are not only suitable for KS L 4201 and KS L 1001 at $1250^{\circ}C$ but it is also possible to apply for ceramic and sanitary ware because specific gravity was about 15 % lighter than general ceramic materials.

• Journal of Korea Port Economic Association
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• v.28 no.2
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• pp.1-27
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• 2012

As more manufacturing and global businesses are being pulled into the port area, the idea of a Port Business Valley (PBV) is being pondered as it would create jobs and added value. The PBV would be centered around the harbor and be connected to the port, a logistics district, an industrial district, and the city. The resulting domestic and foreign investment in logistics, industry, business, tourism, living, etc. would vitalize the geographical characteristics of Incheon Port. It would also generate the largest amount of ripple effects between industries in the PBV. However, up until recently, the most frequently offered examples of planning that have helped logistics of a port to grow that have used a PBV have been those of Busan New Port and Gwangyang Port. However, this study is the result of the recent inception of the idea of creating a PBV centered around Incheon Port and the need for experts to develop a plan for such a PBV in Incheon by conducting a site specific study. The aim of this study is to set up the concept of PBV and establish PBV model of Incheon Port. In addition, this study identifies construct factors and their strategies for establish PBV of Incheon Port and then, shows the key factors and related-strategies on Fuzzy-AHP analysis from a survey of logistics experts with Incheon Port.

• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.499-520
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• 2020

Input ratio of electricity to other production inputs in the Korean manufacturing sector has been higher than for the other OECD countries. In addition, electricity prices in Korea has been relatively lower than the average of OECD countries. Moreover, electricity sector is responsible for most CO2 emissions in Korea as coal and natural gas account 41.9% and 26.8% of electricity production as of 2018. Therefore, it looks inevitable to raise the electricity tariff for the manufacturing sector in Korea, but there is a concern that increase in the electricity tariff might affect small and medium enterprises (SMEs) more than large firms. This study estimates electricity demand's price and output elasticities for large firms and SMEs in steel industry by employing a time varying parameter model (Kalman filter). The analysis shows that changes in output levels regardless of firms' size affect electricity demands more significantly than do changes in electricity prices. Second, large firms have higher variances for both price and output elasticities of electricity demand. Third, large firms have higher price elasticity but lower output elasticity of electricity demand relative to SMEs. Policy implications are suggested in association with how to reduce electricity demands in the energy-intensive industry.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.161-173
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• 2021

The shipping industry plummeted and was depressed due to the global economic crisis caused by the bankruptcy of Lehman Brothers in the US in 2008. In 2020, the shipping market also suffered from a collapse in the unstable global economic situation due to the COVID-19 pandemic, but unexpectedly, it changed to an upward trend from the end of 2020, and in 2021, it exceeded the market of the boom period of 2008. According to the Clarksons report published in May 2021, the decrease in cargo volume due to the COVID-19 pandemic in 2020 has returned to the pre-corona level by the end of 2020, and the tramper bulk carrier capacity of 103~104% of the Panamax has been in the ports due to congestion. Earnings across the bulker segments have risen to ten-year highs in recent months. In this study, as factors affecting BDI, the capacity and congestion ratio of Cape and Panamax ships on the supply side, iron ore and coal seaborne tonnge on the demand side and Granger causality test, IRF(Impulse Response Function) and FEVD(Forecast Error Variance Decomposition) were performed using VAR model to analyze the impact on BDI by congestion caused by strengthen quarantine at the port due to the COVID-19 pandemic and the loading and discharging operation delay due to the infection of the stevedore, etc and to predict the shipping market after the pandemic. As a result of the Granger causality test of variables and BDI using time series data from January 2016 to July 2021, causality was found in the Fleet and Congestion variables, and as a result of the Impulse Response Function, Congestion variable was found to have significant at both upper and lower limit of the confidence interval. As a result of the Forecast Error Variance Decomposition, Congestion variable showed an explanatory power upto 25% for the change in BDI. If the congestion in ports decreases after With Corona, it is expected that there is down-risk in the shipping market. The COVID-19 pandemic occurred not from economic factors but from an ecological factor by the pandemic is different from the past economic crisis. It is necessary to analyze from a different point of view than the past economic crisis. This study has meaningful to analyze the causality and explanatory power of Congestion factor by pandemic.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.5-6
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• 1972

Noise and air pollution, which accompany the development of industry and the increase of population, contribute to the deterioration of urban environment. The air pollution level of Seoul has gradually increased and the city residents are suffering from a high pollution of noise. If no measures were taken against pollution, the amount of emission of pollutant into air would be 36.7 thousand tons per year per square kilometer in 1975, three times more than that of 1970, and it would be the same level as that of United States in 1968. The main sources of air pollution in Seoul are the exhaust has from vehicles and the combustion of bunker-C oil for heating purpose. Thus, it is urgent that an exhaust gas cleaner should be instaled to every car and the fuel substituted by less sulfur-contained-oil to prevent the pollution. Transportation noise (vehicular noise and train noise) is the main component of urban noise problem. The average noise level in downtown area is about 75㏈ with maximum of 85㏈ and the vehicular homing was checked 100㏈ up and down. Therefore, the reduction of the number of bus-stop the strict regulation of homing in downtown area and a better maintenance of car should be an effective measures against noise pollution in urban areas. Within the distance of 200 metres from railroad, the train noise exceeds the limit specified by the pollution control law in Korea. Especially, the level of noise and steam-whistle of train as measured by the ISO evaluation can adversely affect the community activities of residents. To prevent environmental destruction, many developed countries have taken more positive action against worsening pollution and such an action is now urgently required in this country.