• Journal of Astronomy and Space Sciences
• /
• v.38 no.4
• /
• pp.193-202
• /
• 2021

We present analysis results of Korean VLBI Network (KVN) four-band data for the highly variable blazar 3C 279. We measured the 22, 43, 86, and 129 GHz flux densities and spectral indices of the source using contemporaneous data taken over 5.6 years. We used the discrete correlation function to investigate correlations between the radio emission properties and those measured in the optical (2 × 10¹⁴ - 1.5 × 10¹⁵ Hz), X-ray (0.3-10 keV), and gamma-ray (0.1-300 GeV) bands. We found a significant correlation between the radio spectral index and gamma-ray flux without a time delay and interpreted the correlation using an extended jet scenario for blazar emission.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.37.1-37.1
• /
• 2018

ZwCL 1447.2+2619 is a merging galaxy cluster at z=0.37 with clear substructures in X-ray emission and galaxy distribution. In addition, the system possesses distinct radio relics. In order to constrain the merger scenario, it is necessary to measure both the distribution and mass of the cluster dark matter. We perform a weak lensing analysis of ZwCL 1447.2+2619 using Subaru imaging data. After carefully addressing instrumental systematics, we detect significant lensing signals. In this talk, our methodology, weak lensing results, and possible merging scenarios will be presented.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2012.07a
• /
• pp.10-14
• /
• 2012

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2012.07a
• /
• pp.23-29
• /
• 2012

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2012.07a
• /
• pp.15-22
• /
• 2012

• Journal of Climate Change Research
• /
• v.7 no.3
• /
• pp.257-268
• /
• 2016

Both economic growth and industrial structure have great influence on energy consumption and GHG emissions. This study analyzed long-term scenarios for GHG emissions projections considering economic growth and industry value added change. In consideration of 3 GDP and 3 industry value added outlook, total 9 scenarios were set; 'Assembly Industry Baseline(AI)', 'Assembly KEIT industry(AK)', 'Assembly Advanced Country industry(AA)', 'KDI Industry Baseline(KI)', 'KDI KEIT industry(KK)', 'KDI Advanced Country industry(KA)', 'OECD Industry Baseline(OI)', 'OECD KEIT industry(OK)', and 'OECD Advanced Country industry(OA)' scenarios. In consideration of the GDP increase rate and industry value added outlook, it is estimated that AI scenario's GHG emissions would be 777 million tons of $CO_2eq$ in 2030. On the other hand, in the case of OA scenario, GHG emissions would be 560.2 million tons of $CO_2eq$ in 2030. Differences between AI scenario's and OA scenario's were 216.8 million tons of $CO_2eq$. It can be identified by that GDP and industry value added change have great influence on GHG emissions. In view of the fact that Korea's amount of GHG emission reduction targets in 2030 were 218.6 million tons of $CO_2eq$ that the result of this research could give us valuable insight.

• Journal of Environmental Impact Assessment
• /
• v.6 no.2
• /
• pp.93-102
• /
• 1997

Acid rain below pH 5.6 is responsible for 40% of annual precipitation in Korea and it is more serious especially in major cites. Because of that, it is urgent to make measures to reduce the emission of $SO_2$, one of the major air pollutants causing acid rain. The national total emission of $SO_2$ in 1994 was estimated as 1.6 million tons. The $SO_2$ emission in 2020, is expected to increase up to 3.2 million tons, about 2 times that of 1994 under Business-As-Usual scenario. We could take various $SO_2$ reduction measures such as installing desulfurization facilities, the supply of low-sulfur oil and clean fuel(LNG), energy savings, upgrading of production process. However, it is necessary to check the economic feasibility and the attainability to reduction target with a dynamic optimization mode, "Global 2100 Model". The cost-benefit analyses for the measures using the revised "Global 2100 Model" clearly revealed that the desulfurization facilities should be introduced to reduce the $SO_2$ concentration to 0.01 ppm with fuel substitution. If the introduction of desulfurization facilities is delayed, We can not attain the goal of Ministry of Environment before the year of 2012, even in the case that almost all the fuels would be substituted with LNG.

• Transactions of the Korean hydrogen and new energy society
• /
• v.20 no.1
• /
• pp.9-21
• /
• 2009

As one of the alternative solution for energy and environmental issues such as climate change, energy security, oil price, etc., hydrogen energy has been getting so much attentions these days. This paper analyzed the $CO_2$ emission, costs, and energy consumptions when the hydrogen energy was introduced to transportation, specifically in Sedan sector using the energy system model, MARKAL. As results, 21.5% of $CO_2$ emission in 2040 could be reduced and additional 76 billion dollars will be needed in the high energy price scenario. The amount of energy saving mainly due to the replacement of existing car to hydrogen vehicle was 16% of the final energy consumption in 2040.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.1
• /
• pp.32-39
• /
• 2012

New and renewable energy systems(solar thermal system, photovoltaic system, geothermal system, wind power system) are environmentally friendly technologies and these in South Korea are very important measures to reduce greenhouse-gas(GHG) and to push ahead with Green Growth. The purpose of this paper is to analyze GHG mitigation potential by distribution of solar thermal system in housing sector with bottom-up model called 'Long-range Energy Alternative Planning system'. Business as usual(BAU) was based on energy consumption characteristic with the trend of social-economic prospects and the volume of housing. The total amount of GHG emission of BAU was expected to continuous increase from 66.0 million-ton $CO_{2e}$ in 2007 to 73.1 million-ton $CO_{2e}$ in 2030 because of the increase of energy consumption in housing. The alternative scenario, distribution of solar thermal system in housing sector had GHG mitigation potential 1.54 million-ton $CO_{2e}$ in 2030. The results of this study showed that new and renewable energy systems made a contribution of reducing the use of fossil fuel and the emission of greenhouse-gas in building.

• Journal of Energy Engineering
• /
• v.25 no.3
• /
• pp.136-148
• /
• 2016

We analyze economic effects of GHG reduction measures of the generation industry to meet 2030 GHG reduction target using the scenario based approach. We estimate the GHG emission of the Korean power industry in 2030 based on both the $7^{th}$ Electricity Supply & Demand Plan and the GHG emission coefficients issued by IAEA. We set up three scenarios for reduction measures by replacing the coal fired plants with nuclear power, renewable energy and carbon capture and storage. Once and for all, the nuclear power scenario dominates the other energy technologies in terms of GHG reduction quantities and economic effects.