• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.28.1-28.1
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• 2010

Recent surveys have shown that many early-type galaxies have signatures of ongoing or recent star formation (RSF). These RSF galaxies show blue integrated UV-optical colours that set them aside in the NUV integrated colour-magnitude relation. Among them, NGC 4150 has been observed using the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope to inspect the galaxy with higher spatial resolution. In the WFC3 data, the galaxy reveals ubiquitous near-UV emission and remarkable dusty substructure. Our analysis shows this galaxy to lie in the near-UV green valley, and its pixel-by-pixel photometry exhibits a narrow range of UV-optical colours that are similar to those of nearby E+A (post-starburst) galaxies, and lie between those of M83 (an actively star-forming spiral) and the local quiescent early-type galaxy population. This work reaffirms our hypothesis that minor mergers play a significant role in the evolution of early-type galaxies at late epochs.

• Architectural research
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• v.15 no.3
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• pp.143-150
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• 2013

The Korean government recently has rediscovered the potential value of Han-Ok, the Korean traditional house, as an eco-friendly building. In order to objectively verify the environmental performance of Han-Ok as a low carbon green building, this paper suggests the analysis method of GHG emission load of Korean traditional house, based on Life Cycle Assessment, which is commonly abbreviated to "LCA". The environmental impacts caused by building construction and operation can be analyzed through the sum of input and output data from every phase. The study particularly describes the GHG reduction effect by using traditional building materials such as wood products, traditional clay roof tiles, and mud, which are mainly used to construct Han-Ok. Also the study proposes the method for comparative analysis of quantity of GHG emissions in building's entire life cycle so that the data can be used as a reliable basis to optimize the environmental performance of building.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.322.2-322.2
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• 2014

Lighting emitting diodes of n-ZnO/MQW/p-GaN structure are fabricated and investigated. To realize this LED structure, n-ZnO/MQW/p-GaN are grown by MOCVD. At several bias voltages, blue-green light is emitted from the ZnO mesa edge. However, the emission is restricted near the mesa edge. It is seen that the hole current does not spread well. It is because conductivity of p-GaN is extremely small. The break down voltage of the device is small compared to conventional InGaN/GaN LEDs. It is seen that ZnO columnar grain boundaries act as leakage current paths and non-radiative recombination center.

• Journal of Information Display
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• v.13 no.3
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• pp.107-111
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• 2012

An almost pure phase of $Ba_3Si_6O_{12}N_2$ doped with $Eu^{2+}$ was successfully synthesized through the ammonia nitridation of an oxide precursor prepared through an aqueous-solution method, using propylene- glycol-modified silane. The emission peak intensity of the obtained $Ba_3Si_6O_{12}N_2:Eu^{2+}$ was -2.2 times higher than that of the sample prepared through a solid-state reaction method.

• KIEAE Journal
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• v.7 no.1
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• pp.41-48
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• 2007

This research has been carried out to give economical incentives and to promote for the eco-friendly village. A standard model plan for the Korean eco-village has been prepared by systematically applying the results of the research to Boksoo village, which served as an exemplary model. Plans for promoting the Korean eco-village are finally derived after a series of theoretical assessment of conceptual propositions in harnessing natural elements well suited with man-made structures. The eco-friendly village that this study is to develop harnesses natural energy resources and establishes pleasant living environment for human. It minimizes the unjust load against nature and restrains the excessive consumption of irreplaceable indigenous energy and other natural resources on earth. Paraphrasing, the utilization of natural energy resources in the eco-friendly village features various schemes of the related technologies in energy conservation and exploitation of renewable energies including solar thermal, photovoltaic, daylighting, wind power and etc. The eco-friendly village would definitely make our world more healthier than before by suppressing the emission of green house gases from fossil fuels and ever increasing energy consumption.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.213-215
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• 2012

As one of the primary fuel sources, oxy-fuel combustion of coal is actively being investigated because of the climate changing problem such like the emission of green house gases. In this paper research about the pulverized coal technology, which is widely used in both power-generating and iron-making processes was studied to invesgate the ignition behaviour of pulverized coal particles during coal combustion as changing the ambient oxygen concentration of the particle. The ignition phenomenon of the coal particles fed into a laminar flow reactor was imaged with a Integrated charged-coupled device (ICCD) camera. The ignition points were determined throught the analysis of the images, and then the ignition delay times were able to be calculated. The experiment results show that a lower oxygen concentration increases the ignition delay time.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.1
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• pp.39-44
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• 2013

The amount of greenhouse gas (GHG) emissions has been increasing steadily over the last 4 years, averaging 6.8 percent a year, due to the growth of low cost carriers and the increased demand for air transportations. For the aviation GHG reduction, various fuel saving activities are implemented in many areas such as high-efficiency aircraft and bio-fuel development in the technical part and low carbon flight procedures, short cut route development in the operational approach. Among the various reduction technologies, we focused on low carbon flight procedures that are crucial to GHG reduciton and suggested a reduction effect according to target implementation rate using by fuel saving estimation data in each aircraft type.

• Journal of Environmental Impact Assessment
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• v.22 no.1
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• pp.109-116
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• 2013

By IPCC climate change scenario, the socioeconomic actions such as the land use change are closely associated with the climate change as an up zoning action of urban development to increase green gas emission to atmosphere. Prediction of the land use change with rational quality can provide better data for understanding of the climate change in future. This study aims to predict land use change of Cheongju in future and SLEUTH model is used to anticipate with the status quo condition, in which the pattern of land use change in future follows the chronical tendency of land use change during last 25 years. From 40 years prediction since 2000 year, the area urbanized compared with 2000 year increases up to 87.8% in 2040 year. The ratios of the area urbanized from agricultural area and natural area in 2040 are decreased to 53.1% and 15.3%, respectively.

• Journal of the Semiconductor & Display Technology
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• v.4 no.3 s.12
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• pp.17-22
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• 2005

LED lamp was designed by the serial-parallel integration of LED chips in metal-interconnection. The 7 $4.5{\times}4.5\;in^{2}$ masks were designed with the contact type of chrome-no mirror?dark. The white epitaxial thin film was grown by metal-organic chemical vapor deposition. The active layers were consisted with the serial order of multi-quantum wells for blue, green and red lights. The fabricated LED chip showed the electroluminescence peaked at 450, 560 and 600 nm. For the current injection of 20 mA, the operating voltage was measured to 4.25 V and the optical emission power was obtained to 0.7 $\mu$W.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.35-36
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• 2009

Development trend and current status were surveyed for pre-heat-treated high strength cold heading quality (CHQ) wire and it's forming technology. Spheroidizing, quenching, and tempering heat treatments are eliminated by adapting the pre-treated wire, which could reduce energy consumption rate and green house gas emission rate during produce parts requiring high strength. There are some challenging problems to expand application area such as enhancing forming tool life, and preventing delayed failure. Domestic research movement concerning the development and application of the new high strength wire was introduced.