• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.40.2-40.2
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• 2014

The connection between the active galactic nuclei (AGNs) and star formation activity is one of the most important issues in understanding the coevolution of supermassive black holes (SMBHs) and galaxies. In our recent study, by using SDSS quasar spectra we found that the emission-line flux rations involving a nitrogen line, i.e., $NV{\lambda}1240$, correlate with the Eddington ratio. This correlation suggests that the mass accretion into SMBH is associated with a post-starburst phase, when AGB stars enrich the interstellar medium with the nitrogen. Moreover, we focused on nitrogen-loud quasars, which have prominent emission lines of the nitrogen, to investigate whether this argument is correct or not. We will present our recent results described above and discuss the relation between the star formation and feeding to SMBHs.

• Journal of Advanced Navigation Technology
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• v.17 no.3
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• pp.271-278
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• 2013

In this paper, ECEF to ECI coordinate transformation algorithm which uses EOP parameters in GPS civil navigation message is introduced, and ECEF to ECI coordinate transformation simulation results were analyzed. The ECEF to ECI coordinate transformation includes GPS to UTC, and UTC to other types of time conversions and EOP data processing algorithms. The ECEF to ECI coordinate conversion algorithm was certified using real LEO satellite position, velocity GPS data, and EOP data which offered by the Earth Orientation Center.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.243-247
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• 2009

The prevalence of liver and intestinal helminth infections, including Opisthorchis, Haplorchis, Phaneropsolus, hookworms, Enterobius, and Taenia, was surveyed in Khammouane province, Lao PDR. Fecal specimens were collected from 1,242 people (590 men and 652 women) in 3 Mekong riverside villages and were examined by the Kate-Katz thick smear technique. The overall helminth egg positive rate was 81.1%. The positive rate for small trematode eggs, including Opisthorchis viverrini, heterophyids, and lecithodendriids, was 81.1% and the positive rate for hookworms was 6.7%. To obtain adult worms, 35 people who were positive for small trematode eggs were treated with 20-30 mg/kg praziquantel and 10-15 mg/kg pyrantel pamoate, and then purged. Diarrheic stools were collected from 33 of these people and searched for helminth parasites using a stereomicroscope. Mixed infections with various helminths (Haplorchis taichui, Haplorchis yokogawai, Prosthodendrium molenkampi, Phaneropsolus bonnei, echinostomes, hookworms, Trichostrongylus spp., Trichuris trichiura, Enterobius vermicularis, and/or Taenia saginata) were found. The total number of helminth specimens collected was 20,907 (approximately 634 per person). The most common species was H. taichui, followed by P. molenkampi, 0. viverrini, P. bonnei, E. vermicularis, hookworms, and Trichostrongylus spp. These results show that diverse species of intestinal nematodes, trematodes, and cestodes are infecting humans in Khammouane province, Lao PDR.

• Journal of the Korean Statistical Society
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• v.22 no.2
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• pp.283-306
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• 1993

An outlier detection diagnostic for the detection of k-consecutive atypical observations is considered. The proposed diagnostic is based on the innovational variance estimate utilizing both the interpolated and the predicted residuals. We adopt the interpolation method to construct the proposed diagnostic by replacing atypical observations. The perfomance of the proposed diagnositc is investigated by simulation. A real example is presented.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.259-263
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• 2006

• Journal of the Korean housing association
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• v.27 no.6
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• pp.19-29
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• 2016

As a lifeway and social change, the neighborhood build up around elementary school based on Perry's Neighbourhood Unit becomes change. Elementary School does not function as a center of residents' activity or community any longer. Activities occurred near the school move to the community streets that many facilities are distributed to, while utilization of facilities near schools becomes lower. On the bases of the current states, this study aims to draw a practical neighborhood center of residential areas by case study. The research is being mainly about low-rise residential areas in Seoul which includes one elementary school at least. In order to deduct the center of neighborhood, the survey takes two steps. At the preliminary survey, conduct the observation and do an interview to investigate awareness and actual status. Also to analyze practical center, do a main survey about land value, pedestrian volume, distribution of public transit and facility density. The research result shows that there is another activated center street not nearby elementary school in every case. This study assumes that the neighborhood center is not limited around elementary school and could variously build up by circumstances. It has significance that we present a question about the traditional theory and also could be references of the future city maintenance in the long term.

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.119-128
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• 2009

Purpose: The aim of this study was to evaluate the stemness of cells from canine dental tissues and bone marrow. Methods: Canine periodontal ligament stem cells (PDLSC), alveolar bone stem cells (ABSC) and bone marrow stem cells(BMSC) were isolated and cultured. Cell differentiations (osteogenic, adipogenic and chondrogenic) and surface antigens (CD146, STRO-1, CD44, CD90, CD45, CD34) were evaluated in vitro. The cells were transplanted into the subcutaneous space of nude mice to assess capacity for ectopic bone formation at 8 weeks after implantation. Results: PDLSC, ABSC and BMSC differentiated into osteoblasts, adipocytes and chondrocytes under defined condition. The cells expressed the mesenchymal stem cell markers differently. When transplanted into athymic nude mice, these three kinds of cells with hydroxyapatite /${\beta}$- tricalcium phosphate (HA/TCP) carrier showed ectopic bone formation. Conclusions: This study demonstrated that canine dental stem cells have stemness like bone marrow stem cells. Transplantation of these cells might be used as a therapeutic approach for dental stem cell-mediated periodontal tissue regeneration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1022-1028
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• 2013

Chaga mushroom (Inonotus obliquus) was considered a functional food with an anti-cancer effect in colon, gastric, and lung cancer. Therefore, this study was conducted in order to elucidate the effect of chaga mushroom extract in brain cancer. Glioblastoma U-87 MG cells were used in investigation of cell survivability, apoptosis, and cell cycle arrest analysis. Treatment with various concentrations of chaga mushroom extract resulted in inhibition of cell proliferation and cell cycle arrest. Although caspase-3 expression was increased over $100{\mu}g/mL$ of chaga mushroom extract treatment, apoptosis factors with Bcl-2, Bax and p53 did not change. In analysis of cell cycle regulatory factors, expression of cyclin D1 and CDK2 decreased in a dose-dependent manner. We have demonstrated the anti-cancer effect of chaga mushroom extract in glioblastoma, which may be mediated by activation of the caspase pathway and induction of cell cycle arrest.

• Journal of The Korean Astronomical Society
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• v.49 no.1
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• pp.25-35
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• 2016

Multiple color selection techniques are successful in identifying quasars from wide-field broadband imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at 5 ≲ z ≲ 5.7 due to the limitations of filter sets in previous studies. In this work, we present a new selection technique of high redshift quasars using a sequence of medium-band filters: nine filters with central wavelengths from 625 to 1025 nm and bandwidths of 50 nm. Photometry with these medium-bands traces the spectral energy distribution (SED) of a source, similar to spectroscopy with resolution R ~ 15. By conducting medium-band observations of high redshift quasars at 4.7 ≤ z ≤ 6.0 and brown dwarfs (the main contaminants in high redshift quasar selection) using the SED camera for QUasars in EArly uNiverse (SQUEAN) on the 2.1-m telescope at the McDonald Observatory, we show that these medium-band filters are superior to multi-color broad-band color section in separating high redshift quasars from brown dwarfs. In addition, we show that redshifts of high redshift quasars can be determined to an accuracy of Δz/(1 + z) = 0.002 - 0.026. The selection technique can be extended to z ~ 7, suggesting that the medium-band observation can be powerful in identifying quasars even at the re-ionization epoch.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.239-244
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• 2004

Recently automatic equipment has been well popularized for the erythrocyte sedimentation rate, a widely used test, but no standard quality control has been established yet. Thus, we are going to report a case that established and applied a quality control method using the TEST 1 automatic analyzer. For internal quality control, we adopted the repeatability test through comparison with daily mean check, with a manual method using patients' specimens and with the results of a test on the previous day. In order to set the tolerance standard for each quality control method, we compared the results of 50 specimens that showed a wide range of ESR results and examined correlation and differences according to result. After setting the tolerance standard, we applied the standard at tertiary university hospitals for 120 days and investigated positive rates and re-examination rates. If the tolerance standard was exceeded, the cause was also identified. We selected a specimen of below 25 mm/hr (T1), one between 26-50 mm/hr (T2) and one of over 51 mm/hr (T3) at random. The correlation between the manual method and the automatic method was quite high (r=0.98), and it is found appropriate to set based on differences in result values below 25 mm/hr, the upper limit of the reference value, and based on differences in the percentage of result values above 25 mm/hr. Accordingly, we set the criteria for rejection above 10 mm/hr and above 20%. When the criteria were applied in the laboratory, 1.7% of specimens in the range of T1, 8.3% of those in the range of T2 and 7.5% of those in the range of T3 were rejected. Because all the rejected ones fell within the tolerance limit in re-examination calibration verification was not carried out. With the wide popularization of erythrocyte sedimentation rate analyzers that can carry out a lot of tests quickly using automatic methods, it is necessary to improve the reliability of test results by establishing internal quality control policies. We expect that an agreed standard quality control method may be established based on the method proposed in this study.