• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.72.1-72.1
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• 2021

Galaxy mergers are known to have been one of the main drivers in galaxy evolution in a wide range of environments. However, in galaxy clusters, high-speed encounters have been believed to undermine the role of mergers as a driver in galaxy evolution. Nonetheless, a high fraction (~38% in Sheen et al. 2012 and ~20% in Oh et al. 2018) of galaxies with post-merging features have been reported in deep (>~28 mag/arcsec2) optical surveys of cluster galaxies. The authors argue that these galaxies could have merged outside of the cluster and, later, fallen into the cluster, sustaining their long-lasting post-merging features. On the other hand, when galaxy clusters interact, galaxy orbits might be destabilized resulting in a higher galaxy merger rate. To test this idea, we measure the ongoing-merger fraction of galaxies in deep DECam mosaic data of seven Abell clusters (A754, A2399, A2670, A3558, A3574, A3659 and A3716) with a variety of dynamical states (0.016

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.55.2-55.2
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.70.1-70.1
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• 2009

• Bulletin of the Korean Space Science Society
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• 2009.04a
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• pp.39.1-39.1
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• 2009

• The Bulletin of The Korean Astronomical Society
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• v.25 no.1
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• pp.26-26
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• 2000

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.115-117
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• 2007

This paper presents a new systematic approach to find a global solution to economic dispatch (ED) with multiple fuel units using a function merger (FM). Currently, no systematic approach has been developed to find a global solution to economic dispatch with multiple fuel units. Various heuristic methods have been proposed, however it is almost impossible to guarantee a global solution by those methods yet. The proposed method uses the FM and $\lambda$-P functions. A FM merges several fuel cost functions into one that satisfies the optimal conditions of an ED. The FM procedures are described in detail with illustrative examples.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.76.2-76.2
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• 2019

Shells in early-type galaxies are low surface brightness tidal debris, which are wide concentric arcs of overdense stellar regions with large opening angles. The most widely accepted mechanism today for shell formation is the merger scenario, but the dominant merger type producing shells is not clearly understood yet: major/minor and wet/dry mergers. Since shells are regarded as smoking-gun evidence of merging events, detailed understanding of shell galaxies is very useful to constrain the formation process of early-type galaxies. In this study, we investigate the metallicity gradients of eight early-type shell galaxies using CALIFA IFU data to better understand the nature and origins of galaxy shells. We estimate simple stellar population properties out to three effective radius from the measurement of Lick/IDS absorption line indices. We compare the metallicity gradients of shell galaxies with those of normal early-type galaxies in the same mass range. In this presentation, we discuss how much the gradients of shell galaxies are different from those of normal early-type galaxies and what the existence of galaxy shells implies about galaxy formation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.109-110
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• 2014

본 논문에선 우선 MA(Merger and Acquision) 영역을 파악하고자 한다. MA 영역은 장비의 성능향 상 및 가격 하락과 매우 영향이 깊은 영역이다. 우리는 그 영역 중에서 장비 교체 시 원가절감 효과가 가능한 영역, 서버, 스토리지, 소프트웨어의 As-is vs To-be 원가를 비교 분석한다. 그리하여 기업의 소유자 또는 경영자가 기업 및 경영상태 전반에 대한 방향을 결정하는 의사결정 근거로 활용한다.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.67.2-67.2
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• 2021

We present preliminary results on the chemical and kinematic analysis of accreted and heated metal-rich (-1.0 < [Fe/H] < -0.3) stars in the Galactic disk. These stars are in the ranges of e > 0.7, -100 < V_𝜙 < 100 km/s, and |Z| < 3 kpc, and are presumably heated (accreted) by (from) past merger events such as Gaia Enceladus and Sausage (GSE). These stars are largely separated into two groups based on the level of [α/Fe] and radial velocity dispersion. The first group has low [α/Fe] and high radial velocity dispersion, and the second group shows high [α/Fe] and low radial velocity dispersion. We propose that the first group of stars are accreted from the GSE galaxy, whereas the second group of stars are dynamically heated by the GSE merger event.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.61-69
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• 2019

This study analyzed the process of university mergers that took place in Finland and Norway in order to present policy implications for the Korean government considering university merger as an effective policy instrument for restructuring of the Korean higher education system. Based on reviewing the previous literature and related documents, researchers conducted a comparative case study on the context, strategies, and outcomes of the implementation of university merger policies of the two countries. The results of analyses suggested that combination of government's clear direction-setting and enhanced autonomy of merging institutions was essential for successful mergers. Considerations on upgrading the structure of the whole higher education sector to meet new needs of the future society were also suggested.