• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2012년도 춘계학술발표회 초록집
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• pp.190-193
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• 2012

The tools that classify the severity of patients based on the prediction of mortality include APACHE, SAPS, and MPM. Theses tools rely crucially on the evaluation of patients' general clinical status on the first date of their admission to ICU. Nursing activities are one of the most crucial factors influencing on the quality of treatment that patients receive and one of the contributing factors for their prognosis and safety. The purpose of this study was to identify the goodness-of-fit of CPSCS of critical patient severity classification system(CPSCS) and Glasgow coma scale(GCS) and the clinical usefulness of its death rate prediction. Data were collected from the medical records of 187 neurological patients who were admitted to the ICU of C University Hospital. The data were analyzed through $x^2$ test, t-test, Mann-Whitney, Kruskal-Wallis, goodness-of-fit test, and ROC curve. In accordance with patients' general and clinical characteristics, patient mortality turned out to be statistically different depending on ICU stay, endotracheal intubation, central venous catheter, and severity by CPSCS. Homer-Lemeshow goodness-of-fit tests were CPSCS and GCS and the results of the discrimination test using the ROC curve were $CPSCS_0$,.734, $GCS_0$,.583, $CPSCS_{24}$,.734, $GCS_{24}$,.612, $CPSCS_{48}$,.591, $GCS_{48}$,.646, $CPSCS_{72}$,.622, and $GCS_{72}$,.623. Logistic regression analysis showed that each point on the CPSCS score signifies1.034 higher likelihood of dying. Applied to neurologically ill patients, early CPSCS scores can be regarded as a useful tool.

• 천문학회보
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• 제42권2호
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• pp.77.4-78
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• 2017

The presence of double red clump (RC; metal-rich counterpart of horizontal-branch) in high latitude field of the Milky Way (MW) bulge is widely interpreted as evidence for an X-shaped structure originated from the bar instability. However, Lee et al. (2015) recently suggested an alternative model, according to which the double RC is metal-rich manifestation of multiple stellar population phenomenon observed in globular clusters (GCs). Here we show that stars in bright RC are enhanced in CN compared to those in faint RC from our low-resolution spectroscopy. CN traces N, and N-rich stars are also enhanced in Na and He in GCs. Since GCs are the only environment that produce second generation stars with enhanced N, Na, & He, this is a direct evidence that stars in the classical bulge component of the MW were mostly provided by proto-GCs.

• 천문학회보
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• 제46권1호
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• pp.29.3-29.3
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• 2021

Globular clusters (GCs) form at the very early stage of galaxy formation, and thus can be used as an important clue indicating the environment of the galaxy formation era. Although various GC formation scenarios have been suggested, they have not been examined in the cosmological context. Here we introduce the 'particle tagging method' in order to investigate the formation scenarios of GCs in a galaxy cluster. This method is able to trace the evolution of GCs that form in the dark matter halos which undergo the hierarchical merging events in galaxy cluster environments with an effective computational time. For this we use dark matter merger trees from the cosmological N-body simulation. Finally, we would like to find out the best GC formation scenario which can explain the observational properties of GCs in galaxy clusters.

• 토지주택연구
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• 제11권1호
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• pp.39-48
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• 2020

Main research question of this study is about whether gated community (GC) as private urban governance gets along with local public goods by locating near to them. We examine this question through testing the Tiebout hypothesis from case study of Seoul, capital city of South Korea, in which GCs are so common to test the assumption empirically. For this, we examine the meaning of GC in 3 Es viewpoints; conceptualize the framework of Tieboutian co-evolution of GC and local public goods by hedonic price modeling. As a result, possibilities are found that GCs are to be seen from different point of view, viz. co-evolutionary mechanism between private and public governance; GCs effectively capture and represent the demand of residents for local public goods through voting by their collective locational choice. It allows us different kind of approach to investigate APTs as a co-evolutionary form of private and public urban order rather than seeing them only as a tool of speculative investment, particularly in rapidly urbanizing countries like Korea.

• BMB Reports
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• 제39권5호
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• pp.586-594
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• 2006

Germinal centers (GCs) have been identified as site at which the somatic mutation of immunoglobulins occurs. However, somatic mutations in immunoglobulins have also been observed in animals that normally do not harbor germinal centers. This clearly indicates that somatic mutations can occur in the absence of germinal centers. We therefore attempted to determine whether or not GCs exist in TNFR1-deficient mice, and are essential for the somatic mutation of immunoglobulins, using (4-hydroxy-3-nitropheny)acetyl-ovalbumin (NP-OVA). Both wild-type and TNFR1-deficient mice were immunized with NPOVA, and then examined with regard to the existence of GCs. No typical B-cell follicles were detected in the TNFR1-deficient mice. Cell proliferation was detected throughout all splenic tissue types, and no in vivo immune-complex retention was observed in the TNFR1-deficient mice. All of these data strongly suggest that no GCs were formed in the TNFR1-deficient mice. Although TNFR1-deficient mice are unable to form GCs, serological analyses indicated that affinity maturation had been achieved in both the wild-type and TNFR1-deficient mice. We therefore isolated and sequenced several DNA clones from wild-type and the TNFR1-deficient mice. Eight out of 12 wild-type clones, and 11 out of 14 clones of the TNFR-1-deficient mice contained mutations at the CDR1 site. Thus, the wild-type and TNFR1-deficient mice were not extremely different with regard to types and rates of somatic mutation. Also, high-affinity antibodies were detected in both types of mice. Collectively, our data appear to show that affinity maturation may occur in TNFR1-deficient mice, which completely lack GCs.

• 천문학회보
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• 제41권2호
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• pp.36.1-36.1
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• 2016

This is a presentation of the paper published as Kimm et al. 2016, ApJ, 823, 52. We investigate the formation of metal-poor globular clusters (GCs) at the center of two dark matter halos with $Mhalo{\sim}4{\times}107Msun$ at z>10 using cosmological radiation-hydrodynamics simulations. We find that very compact (${\leq}1$ pc) and massive (${\sim}6{\times}105Msun$) clusters form rapidly when pristine gas collapses isothermally with the aid of efficient $Ly{\alpha}$ emission during the transition from molecular-cooling halos to atomic-cooling halos. Because the local free-fall time of dense star-forming gas is very short (${\ll}1Myr$), a large fraction of the collapsed gas is turned into stars before stellar feedback processes blow out the gas and shut down star formation. Although the early stage of star formation is limited to a small region of the central star-forming disk, we find that the disk quickly fragments due to metal enrichment from supernovae. Sub-clusters formed in the fragmented clouds eventually merge with the main cluster at the center. The simulated clusters closely resemble the local GCs in mass and size but show a metallicity spread that is much wider than found in the local GCs. We discuss a role of pre-enrichment by Pop III and II stars as a potential solution to the latter issue. Although not without shortcomings, it is encouraging that a naive blind (not tuned) cosmological simulation presents a possible channel for the formation of at least some massive GCs.

• 천문학논총
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• 제30권2호
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• pp.261-263
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• 2015

The metallicity distribution of globular clusters (GCs) provides a crucial clue for the star formation history of their host galaxy. With the assumption that GCs are generally old, GC colors have been used as a proxy for GC metallicities. Bimodal color distributions of GCs observed in most large galaxies have, for decades, been interpreted as bimodal metallicity distributions, indicating the presence of two populations within a galaxy. However, the conventional view has been challenged by a new theory that non-linear GC color-metallicity relations can cause a bimodal color distribution even from a single-peaked metallicity distribution. Using photometric and spectroscopic data of NGC 5128 GCs in combination with stellar population simulation models, we examine the effect of non-linearity in GC color-metallicity relations on transformation of the color distributions into the metallicity distributions. Although in some colors offsets are present between observations and models for the color-metallicity relations, their overall shape agrees well for various colors. After the offsets are corrected, the observed spectroscopic metallicity distribution is well reproduced via modeled color-metallicity relations from various color distributions having different morphologies. We discuss the implications of our results.

• 천문학회보
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• 제40권1호
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• pp.78.1-78.1
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• 2015

Recent studies for the Milky Way globular clusters (GCs) have reported that most of them host multiple stellar populations. However, only a few GCs have shown abundance variations in heavy elements such as iron and calcium. These GCs, as galaxy building blocks, are important to understand the formation of the Milky Way in hierarchical merging paradigm. In this study, we report our discovery from the Ca narrow-band photometry and low-resolution spectroscopy that NGC 6273 is a new Milky Way building block candidate.

• 천문학회보
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• 제35권2호
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• pp.29.1-29.1
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• 2010

Recent observations reveal that some early-type galaxies show a color-magnitude relation of blue globular clusters (GCs) in the color-magnitude diagrams, which is referred to as 'blue tilt'. This phenomenon is interpreted as a mass-metallicity relation -- metallicities of blue GCs increase with increasing mass, and thus provides a crucial clue to the chemical enrichment processes of GCs as a function of their mass. However, some galaxies show 'non-tilt' or even 'reverse blue tilt' on the blue GC sequence, and thus the origin of blue tilt still remains a puzzle. In this study, we put forward the theoretical explanation for the phenomenon and discuss its implications towards galaxy formation scenarios.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.29.3-29.3
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• 2009

Recent observations for the Galactic globular clusters (GCs) have shown that a number of GCs have characteristic features of multiple stellar populations, such as multiple main-sequences (MSs), splits in sub-giant branch (SGB), bimodal and/or extended horizontal branches (HBs). Based on the population synthesis models, we investigate star formation histories of the GCs with multiple populations, $\omega$ Cen, M54, NGC 1851, NGC 6388, NGC 6441, and NGC 2808, by comparing synthetic model color-magnitude diagrams (CMDs) with observations. We adopt most up-to-date Yonsei-Yale (Y2) stellar evolutionary tracks and isochrones from MS to post-HB, as well as improved color-temperature transformations from the recent stellar atmosphere libraries. Our models show that the observed features can be naturally explained by assuming the presence of helium-enhanced subpopulations.