• 천문학회보
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• 제37권2호
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• pp.73.2-73.2
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• 2012

Matusoka & Kawara (2010) showed that the number density of the most massive galaxies (log $M/M_{\odot}=11.5-12.0$) increases faster than that of the next massive group (log $M/M_{\odot}=11.0-11.5$) during 0 < z < 1. This appears to be in contradiction to another important empirical concept of "downsizing". We attempt to understand the two observational findings in the context of the hierarchical merger paradigm using semi-analytic techniques. Our models closely reproduce the result of Matusoka & Kawara (2010). Downsizing can also be understood as larger galaxies have on average smaller assembly ages but larger stellar ages. Our fiducial models further reveal the details on the history of stellar mass growth of massive galaxies. The most massive galaxies (log $M/M_{\odot}=11.5-12.0$ at z=0), which are mostly brightest cluster galaxies, obtain roughly 70% of their stellar components via merger accretion. The role of merger accretion monotonically declines with galaxy mass: 45% for log $M/M_{\odot}=11.0-11.5$ and 20% for log $M/M_{\odot}=10.5-11.0$ at z = 0. The specific accreted stellar mass rates via galaxy mergers decline very slowly during the whole redshift range, while the specific star formation rates sharply decrease with time. In the case of the most massive galaxies, merger accretion becomes the most important channel for the stellar mass growth at z ~ 2. On the other hand, in-situ star formation is always the dominant channel in the $L_*$ galaxies.

• 디지털융복합연구
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• 제19권9호
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• pp.19-31
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• 2021

온라인플랫폼들의 영향력은 더할 나위 없이 커지며 이들의 막강해진 시장지배력에 대한 규제가 필요하다는 목소리가 높아지고 있다. 국내에서도 플랫폼의 시장지배적 지위 남용과 관련된 다양한 이슈들이 논의되고 있으며 현재 온라인플랫폼 공정화법이 국무회의를 통과한 상황이다. 이에 본 연구에서는 온라인플랫폼 규제를 다양한 이해관계자의 관점으로 바라보고 정책적 방향성을 짚어보고자 한다. 먼저 플랫폼기업이 채택하고 있는 경쟁전략들과 기업결합으로 야기될 수 있는 문제들을 살펴본 후, 온라인플랫폼에 대한 규제가 이해관계자에게 미치는 영향을 플랫폼사업자, 입점업체, 소비자의 관점에서 분석하였다. 본 연구는 온라인플랫폼 규제를 제정함에 있어서 자국플랫폼을 통한 국가경쟁력 향상이라는 경쟁적 이점이 고려되어야함을 강조하고 입점업체 및 소비자 보호를 대변하고자 하는 현재의 온라인플랫폼규제를 보다 균형잡힌 시각으로 바라볼 기회를 제공하고자 한다.

• 산업융합연구
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• 제13권4호
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• pp.11-28
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• 2015

A company have to grow constantly. If a company does not grow and stagnant, it will be finally out of the market. The contemporary companies fully make use of M&A to search for new growth engines. The reason of companies using M&A as a important tool of a business strategy is the fastest way to achieve technology power, market power, competitiveness. The form of M&A was that leading companies take over smaller companies or merger and acquisition between small companies in the middle of 2000. But now, Mega mergers between industry leading companies often occur and especially domestic of course M&A of foreign companies occurs actively. These days the boom of stock market and the big companies are pouring on sale by restructuring, privatization and the basis of low interest will make the M&A market continuously. In this study, I suggest a solution of actual human resources management by analyzing proven M&A cases and search for various problems of a gap in the leadership and communication in connection with integration of organization culture after M&A. First of all, I arrange the theoretical concept of the subject and analyze the key factors of the success M&A cases, lastly I suggested a HR strategy after M&A. After M&A, HR strategy is ; First, a company have to build a organization culture which is that merger company accommodate a excellent organizational characteristic of predecessor company with consideration of culture difference. Second, M&A must proceed to remove of anxiety about the future and employment stability by excellent leaderships. Third, organization integration after M&A is influenced by the level of integration for that reason it was verified that M&A have to make progress by communication of each 2 organizations.

• 지역연구
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• 제38권1호
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• pp.33-44
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• 2022

최근 지방의 인구감소 위기가 점차 심화하면서 지방분권을 확대해야 한다는 목소리가 점차 커지고 있다. 현 정부에서도 '재정분권 추진', '「지방이양일괄법」제정' 등을 통해 분권을 위한 여러 노력을 기울이고 있지만 분권이 오히려 국토 불균형을 악화시킬 수 있다는 우려를 담은 연구도 나오고 있다. 이들 연구는 분권에 앞서 지역 간 격차를 줄이는 선제 조치가 필요함을 강조한다. 지역의 위기를 극복하기 위한 분권 논의와 관련하여 본 연구에서는 우리나라보다 먼저 지방분권을 추진했던 일본의 사례를 살펴보았다. 일본의 지방분권은 국가적 경제위기 속에서 중앙정부의 재정부담을 줄일 목적으로 추진되었다는 점에서 우리나라와는 맥락이 다르다. 하지만 분권 추진 과정에서 행정구역 개편을 통한 공간구조의 재편을 매우 중요하게 고려하였다는 점은 우리가 주목할 만하다. 본 연구는 일본의 분권추진 과정에서 나타난 행정구역 개편 노력을 비판적으로 고찰하고, 일본 사례가 우리나라 분권 논의에 주는 시사점을 도출하였다.

• Journal of Korea Trade
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• 제26권6호
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• pp.118-135
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• 2022

Purpose - The purpose of this study is to investigate the relationships among Chinese state-owned enterprises (SOEs), previous M&A experience, and the probability of deal completion in cross-border mergers and acquisitions (CBMAs). Since Chinese SOEs tend to be recognized by host countries as agents of their home country government, this study argues that SOEs will face difficulties in completing CBMA deals. However, the study expects that these difficulties may vary depending on whether the firm has previous M&A experience because firms can gain the knowledge and capabilities necessary to implement subsequent M&As successfully from past M&A experience. Design/methodology - To investigate our argument, we conduct a logistic regression using a sample of 363 CBMA deals from 304 Chinese publicly listed firms during 2007 to 2017. We used SOEs as an independent variable, experience of domestic and foreign M&As as moderating variables, respectively, and CBMA deal completion as the dependent variable. Findings - The study shows a negative and significant relationship between Chinese SOEs and the completion likelihood of CBMA deals. We find that this negative relationship is strengthened when the firm had prior domestic M&A experience, whereas foreign M&A experience alleviated the negative relationship. Originality/value - The issue of government ownership has remained unclear since government intervention has both advantages and disadvantages in pursuing CBMAs. Our findings support literature that argues Chinese SOEs face legitimacy concerns in the host countries, thereby lowering their CBMA deal completion likelihood. Furthermore, the study enriches the literature by identifying different moderating effects of domestic and foreign M&A experience on the negative relationship between SOEs and CBMA deal completion.

• 천문학회보
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• 제44권2호
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• pp.37.3-37.3
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• 2019

We study the stellar populations of the brightest group galaxies (BGGs) in groups whose halos have different dynamical states, using observational data from the GAMA survey. The two independent indicators to probe the dynamical state of the halo are the magnitude gap between two most luminous galaxies (∆M12) and offset between BGG and the luminosity center (Doffset) of the group. Such indicators complement each other in identifying relaxed and unrelaxed galaxy groups in our samples. We find that the BGGs of unrelaxed groups have significantly bluer NUV-r colours than in relaxed groups. This is also true at fixed sersic index. We find the bluer colours cannot be explained away by differing dust fraction, suggesting there are real differences in their stellar populations. SFRs derived from SED-fitting tend to be higher in unrelaxed systems. This could be partly because there is a greater fraction of BGGs with non-elliptical morphology, but also because unrelaxed systems are expected to have larger numbers of mergers, some of which may bring fuel for star formation. The SED-fitted stellar metallicities of BGGs in unrelaxed systems also tend to be higher, perhaps because the building blocks of the unrelaxed systems were more massive and had more time to enrich themselves. We find that the ∆M12 parameter is the most important parameter behind the observed differences in the relaxed/unrelaxed groups. We also find that groups selected to be unrelaxed using our criteria tend to have higher velocity offsets between the BGG and their group.

• 천문학회보
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• 제44권2호
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• pp.76.1-76.1
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• 2019

After the first identification of electromagnetic counterpart of gravitational wave source (GW170817), era of multi-messenger astronomy has begun. For specifying coordinate, magnitude, and host galaxy information, optical follow-up observation of GW source becomes important. The O3 run of LIGO / VIRGO started after April 2019. We present searching strategy of GW optical counterpart using the KMTNet. By performing tiling observation of high probability area in GW localization map, we expect to observe early light-curve of GW optical counterpart. We will also present observation result for three gravitational wave events of binary black hole mergers. After identification of optical counterpart, we will study collision mechanism, progenitor, and characteristics of host galaxy using observation data of GW source.

• 천문학회보
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• 제45권1호
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• pp.64.2-64.2
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• 2020

We present the properties of galaxies in filaments around the Virgo cluster with respect to their vertical distance from the filament spine. Using the NASA-Sloan Atlas and group catalogs, we select galaxies that do not belong to groups in filaments. The filament member galaxies are then defined as those located within 3.5 scale length from the filament spine. The filaments are mainly (~86%) composed of low-mass dwarf galaxies of logh2M∗/M⊙ < 9 dominantly located on the blue cloud in color-magnitude diagrams. We observe that the g - r color and stellar mass of galaxies correlate with their vertical distance from the filament spine in which the color becomes red and stellar mass decreases with increasing vertical filament distance. The galaxies were divided into two subsamples in different stellar mass ranges, with lower-mass (logh2M∗/M⊙ ≤ 8) galaxies showing a clear negative g-r color gradient, whereas higher-mass (logh2M∗/M⊙ > 8) galaxies have a flat distribution against the vertical filament distance. We observe a negative EW(Hα) gradient for higher-mass galaxies, whereas lower-mass galaxies show no distinct variation in EW(Hα) against the vertical filament distance. In contrast, the NUV - r color distribution of higher-mass galaxies shows no strong dependence on the vertical filament distance, whereas the lower-mass galaxies show a distinct negative NUV - r color gradient. We do not witness clear gradients of HI fraction in either the higher- or lower-mass subsamples. We propose that the negative color and stellar mass gradients of galaxies can be explained by mass assembly from past galaxy mergers at different vertical filament distances. In addition, galaxy interactions might be responsible for the contrasting features of EW(Hα) and NUV - r color distributions between the higher- and lower-mass subsamples. The HI fraction distributions of the two subsamples suggest that ram-pressure stripping and gas accretion could be ignorable processes in the Virgo filaments.

• 경영정보학연구
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• 제19권4호
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• pp.171-182
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• 2017

범세계적 경제위기 이후 많은 기업들은 극심한 경쟁 하에서의 생존 및 경쟁력 강화/유지 전략으로 인수합병(M&A)을 고려하고 있으며, 특히 최근 들어 IT 기반 기술 집약적 기업의 인수합병이 증가하고 있다. 본 연구는 IT 산업에 내재되어 있는 특성에 대한 이해를 바탕으로 IT 기업 인수시 동반되는 위험을 인수합병 이후 기업의 성과에 대한 변동성을 이용하여 정량적으로 측정하고, 더 나아가 인수합병으로 인한 장기적 위험을 완화시킬 수 있는 요인들을 도출하고자 하였다. 1990년에서 2016년까지 이루어진 기업 인수합병 데이터를 이용하여 분석한 결과, 상장 이전 인수/합병 경험이 많은 기업이 IT 기업을 인수하는데 더 적극적이며, 네트워크 외부성 효과로 인해 시장형성 초기 선점효과의 역할이 증대됨에 따라 상대적으로 규모가 작은 비상장 IT 기업들도 많이 인수/합병 대상이 된 것으로 나타났다. 또한 IT 기업을 인수하는 경우 인수 기업의 사후적 기업 성과의 변동성이 증가하지만, 관련 (related) 산업 내에서 IT 기업을 인수할 경우 변동성 증가폭이 완화되는 것을 보여준다.

• Monthly Notices of the Royal Astronomical Society
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• 제491권3호
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• pp.4045-4056
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• 2020

We examine whether galaxy environments directly affect triggering nuclear activity in Sloan Digital Sky Survey (SDSS) local spiral galaxies using a volume-limited sample with the r-band absolute magnitude M_r < -19.0 and 0.02 <z< 0.055 selected from the SDSS Data Release 7. To avoid incompleteness of the central velocity dispersion σ of the volume-limited sample and to fix the black hole mass affecting AGN activity, we limit the sample to a narrow σ range of 130 km s^-1 <σ< 200 km s^-1. We define a variety of environments as a combination of neighbour interactions and local density on a galaxy. After the central star formation rate (which is closely related to AGN activity level) is additionally restricted, the direct impact of the environment is unveiled. In the outskirts of rich clusters, red spiral galaxies show a significant excess of the AGN fraction despite the lack of central gas. We argue that they have been pre-processed before entering the rich clusters, and due to mergers or strong encounters in the in-fall region, their remaining gases efficiently lose angular momentum. We investigate an environment in which many star-forming galaxies coexist with a few starburst-AGN composite hosts having the highest [O_III] luminosity. We claim that they are a gas-rich merger product in groups or are group galaxies in-falling into clusters, indicating that many AGN signatures may be obscured following the merger events.