• Applied Microscopy
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• v.26 no.3
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• pp.349-367
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• 1996

The development of small granule-containing cell in the superior cervical ganglion was studied by electron microscopic method in human fetuses ranging from 40 mm to 260 mm crown rump length (10 to 30 weeks of gestational age). At 40 mm fetus, the superior cervical ganglion was composed of clusters of undifferentiated cells, primitive neuroblasts, and unmyelinated nerve fibers together with blood vessels. At 90 mm fetus, the superior cervical ganglion consisted of neuroblasts, satellite cell, small granule-containing cells, and unmyelinated nerve fibers. Two morphological types of the small granule-containing cells in the superior cervical ganglion were first indentified at 90 mm fetus, but were rare. Type I granule-containing cell occurred in solitary and had long processes, whereas type II cells tend to appeared in clusters near the blood capillaries. The granule-containing cells were characterized by the presence of dense-cored vesicles ranging from $150{\sim}300nm$ in diameter in both the cell bodies and processes. Other organelles included abundant mitochondria, rough endoplasmic reticulum, neurotubules, and widely distributed ribosomes. The granule-containing cells had long processes similar to those found in principal ganglionic cells. They could be identified by their content in dense-cored vesicles. The small granule-containing cells increased somewhat in size and number with increase of fetal age. Synaptic contacts were first found on the solitary granule-containing cell at 150 mm fetus. Synaptic contacts between the soma and processes of type I granule-containing cells and preganglionic axon terminals were observed. In addition, synaptic junctions between the processes of granule-containing cells and presumed dendrite of postganglionic neuron were also observed from 150 mm onward. On the basis of these features type I granule-containing cells could be considered as interneurons. The clusters of type II granule-containing cells were located in the interstitial or subcapsular portions of the ganglion, and had short processes which ended in close relation to fenestrated capillaries. Therefore it may be infer that clusters of type II granule-containing cells have an endocrine function.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.255-259
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• 2015

Recent narrow-band Ca photometry discovered two distinct red giant branch (RGB) populations in some massive globular clusters (GCs) including M22, NGC 1851, and NGC 288. In order to investigate the differences in light/heavy elements abundances between the two subpopulations, we have performed low-resolution spectroscopy for stars on the two RGBs in these GCs. We find a significant difference (more than $4{\sigma}$) in calcium abundance from the spectroscopic HK' index for both M22 and NGC 1851. We also find a more than $8{\sigma}$ difference in CN band strength between the Ca-strong and Ca-weak subpopulations. For NGC 288, however, we detect the presence of a large difference only in the CN strength. The calcium abundances of the two subpopulations in this GC are identical within errors. We also find interesting differences in CN-CH relations among these GCs. While CN and CH indices are correlated in M22, they show an anti-correlation in NGC 288. However, NGC 1851 shows no difference in CH between two groups of stars having different CN strengths. The CN bimodality in these GCs could be explained by pollution from intermediate-mass asymptotic giant branch stars and/or fast-rotating massive stars. For the presence or absence of calcium bimodality and the differences in CN-CH relations, we suggest these would be best explained by how strongly type II supernovae enrichment has contributed to the chemical evolutions of these GCs.

• Monthly Notices of the Royal Astronomical Society
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• v.491 no.3
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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.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.529-530
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• 2015

We investigated the galaxy morphology of 6 Abell clusters at z = 0.0784 - 0.145 based on deep images obtained using MegaCam on the CFHT. For hundreds of galaxies in our data, we classified their morphology based on criteria related to secular or merger related evolution. We found that the morphological mixture of galaxies varies considerably from cluster to cluster. This article contains a general description of our deep imaging campaign and preliminary results for galaxy morphologies in cluster environments.

• The Korean Journal of Cytopathology
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• v.15 no.2
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• pp.120-125
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• 2004

Ewing's sarcoma (ES)/PNET is common in both axial and appendicular skeletons, but is extremely rare in the talus. Here, we report a case of ES/PNET of the left talus in a 29-year-old male patient diagnosed by fine needle aspiration cytology, and review the literature on similar cases. The cytological smears were composed of individually dispersed small round cells and occasional clusters of loosely cohesive cells. The tumor cells were fragile, frequently exhibiting naked nuclei. Two distinct types of cells were observed. The light (chief) cells displayed round or slightly oval nuclei with frequent indentations, generally inconspicuous nucleoli, and a thin rim of cytoplasm, which sometimes harbored small vacuoles. The dark cells were smaller, displaying scanty cytoplasm with dense hyperchromatic nuclei, intermixed with chief cells, and often manifesting as small molded groups. However, no significant nuclear pleomorphisms or mitoses were noted. Tumor cells in the ceil block revealed positive cytoplasmic glycogen, as determined by a PAS stain with diastase control, and also exhibited positive immunoreactivity for CD99.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1411-1418
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• 2005

Obesity is not classed in general psychiatry disease. But, psychoneurotic factor has been known to be a risk factor of obesity. In order to evaluate and understand the psychoneurotic state on obese patient, this study used Minnesota Multiphasic Personality Inventory(MMPI). Total patients were classified into 3 or 5 clusters. MMPI scores were compared according to education, BMI and Sasang Constitution. Multiple regression analysis were used for psychological factor on obese patients by age, height, weight, education, percent body fat, fat distribution, BMI. Based on this study, it was no significantly difference by education level, BMI, sasang(四象) constitution except L profile according to BMI. These result is different from our general recognition of the psychoneurotic state on obese patient. Therefore, the bigger sample study is needed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.45-55
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• 2015

In this paper, we consider curriculum mining as an application of process mining in the domain of education. The basic objective of the curriculum mining is to construct a registration pattern model by using logs of registration data. However, subject registration patterns of students are very unstructured and complicated, called a spaghetti model, because it has a lot of different cases and high diversity of behaviors. In general, it is typically difficult to develop and analyze registration patterns. In the literature, there was an effort to handle this issue by using clustering based on the features of students and behaviors. However, it is not easy to obtain them in general since they are private and qualitative. Therefore, in this paper, we propose a new framework of curriculum mining applying K-means clustering based on subject attributes to solve the problems caused by unstructured process model obtained. Specifically, we divide subject's attribute data into two parts : categorical and numerical data. Categorical attribute has subject name, class classification, and research field, while numerical attribute has ABEEK goal and semester information. In case of categorical attribute, we suggest a method to quantify them by using binarization. The number of clusters used for K-means clustering, we applied Elbow method using R-squared value representing the variance ratio that can be explained by the number of clusters. The performance of the suggested method was verified by using a log of student registration data from an 'A university' in terms of the simplicity and fitness, which are the typical performance measure of obtained process model in process mining.

• The Korean Journal of Community Living Science
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• v.27 no.spc
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• pp.665-679
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• 2016

This study examined the main factors for activating rural tourism of Jeollabuk-do using big data analysis. The tourism big data was gathered from public open data sources and social network services (SNS), and the analysis tools, 'Opinion Mining', 'Text Mining', and 'Social Network Analysis(SNA)' were used. The opinion mining and text mining analysis identified the key local contents of the 14 areas of Jeollabuk-do and the evaluations of customers on rural tourism. Social network analysis detected the relationships between their contents and determined the importance of the contents. The results of this research showed that each location in Jeollabuk-do had their specific contents attracting visitors and the number of contents affected the scale of tourists. In addition, the number of visitors might be large when their tourism contents were strongly correlated with the other contents. Hence, strong connections among their contents are a point to activate rural tourism. Social network analysis divided the contents into several clusters and derived the eigenvector centralities of the content nodes implying the importance of them in the network. Tourism was active when the nodes at high value of the eigenvector centrality were distributed evenly in every cluster; however the results were contrary when the nodes were located in a few clusters. This study suggests an action plan to extend rural tourism that develop valuable contents and connect the content clusters properly.

• Journal of The Korean Astronomical Society
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• v.54 no.1
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• pp.17-35
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• 2021

We study galaxies undergoing ram pressure stripping in the Virgo cluster to examine whether we can identify any discernible trend in their star formation activity. We first use 48 galaxies undergoing different stages of stripping based on H i morphology, H i deficiency, and relative extent to the stellar disk, from the VIVA survey. We then employ a new scheme for galaxy classification which combines H i mass fractions and locations in projected phase space, resulting in a new sample of 365 galaxies. We utilize a variety of star formation tracers, which include g - r, WISE [3.4]-[12] colors, and starburstiness that are defined by stellar mass and star formation rates to compare the star formation activity of galaxies at different stripping stages. We find no clear evidence for enhancement in the integrated star formation activity of galaxies undergoing early to active stripping. We are instead able to capture the overall quenching of star formation activity with increasing degree of ram pressure stripping, in agreement with previous studies. Our results suggest that if there is any ram pressure stripping induced enhancement, it is at best locally modest, and galaxies undergoing enhancement make up a small fraction of the total sample. Our results also indicate that it is possible to trace galaxies at different stages of stripping with the combination of H i gas content and location in projected phase space, which can be extended to other galaxy clusters that lack high-resolution H i imaging.

• Journal of Families and Better Life
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• v.30 no.6
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• pp.151-166
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• 2012

The major findings are(were) as follows: 1) The Eco-friendly consumption behavior was divided into three(3) clusters, namely "The Middle Group" of eco-friendly consumption behavior(cluster I), "The Inferior group" of eco-friendly consumption behavior(cluster II), and "The Excellent Group" of eco-friendly consumption behavior(cluster III). 2) The differences in the general characteristics among the three clusters were founded on the experience of green consumption information and sources of information. 3) The characteristics of cluster I(The Middle Group) were(are) found to be eco-conscious, and aware of the consequences of behaviors, green market conditions and environmental issues. This cluster was the middle-average group. The characteristics of cluster III(The Excellent Group) were(are) found to have the willingness to pay additional costs, being aware of the social norms of the reference group, having an awareness of eco-institutional conditions, being knowledgeable about environmental policy, and finally, being personally involved in green consumption behavior. This cluster was the high-average group, whereas cluster II(The Inferior Group) was the low-average group.