• 천문학회보
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• 제42권1호
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• pp.46.1-46.1
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• 2017

Class I methanol masers are found to be good tracers of the interaction between outflows from massive young stellar objects with their surrounding media. Although polarization observations of Class II methanol masers have been able to provide information about magnetic fi elds close to the central (proto)stars, polarization observations of Class I methanol masers are rare, especially at 44 and 95GHz. We present the results of linear polarization observations of 39 Class I methanol maser sources at 44 and 95GHz. These two lines are observed simultaneously with one of the 21m Korean VLBI Network telescopes in single-dish mode. Approximately 60% of the observed sources have fractional polarizations of a few percent in at least one transition. This is the fi rst reported detection of linear polarization of the 44GHz methanol maser. We also observed 7 targets with the KVN in VLBI mode. We will present its preliminary results, too.

• 천문학회보
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• 제36권2호
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• pp.142.1-142.1
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• 2011

UBVI and $H{\alpha}$ CCD photometry of IC 1848, one of active star-forming regions in Cas OB6, is carried out as a part of Sejong Open cluster Survey (SOS) project. An OB association is an ideal laboratory for studying the triggered star formation and star formation history. Our purposes are to provide deep photometric data up to 21 mag in V and physical parameters of IC 1848. We classify 79 early-type stars and 186 pre-main sequence (PMS) stars as being the members of the cluster using photometric criteria. The IR excess emission PMS stars by Koenig et al. (2008) are also included as members of IC 1848. Total number of members is 414. We derive the interstellar reddening (=$0.659{\pm}0.058$ mag), reddening law ($R_V=4.0{\pm}0.1$), distance modulus ($V_0-M_V=12.0{\pm}0.1$ mag) using the early-type members of IC 1848. We also determine the age of the cluster ($3.5{\pm}1.5$ Myr) by placing the theoretical isochrones on the HR diagram.

• 천문학회보
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• 제36권2호
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• pp.88.1-88.1
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• 2011

Shocks are thought to be important in the dynamics and heating of the solar chromosphere. The observational determination of shock parameters, however, has been hardly done because of the difficulty of observation at a high spatial, temporal and spectral resolution, and the lack of an effective method of inferring physical parameters from spectral data. Our inversion of the spectral data of the $H{\alpha}$ and Ca II 854.2 nm lines simultaneously taken from an intranetwork area, produced temporal profiles of temperature as well as line-of-sight velocities, from which we infer that three-minute chromospheric oscillations prevailing in the upper chromosphere are in fact trains of strong shocks with a strength of about two and a propagation speed of 20 km s-1 that carry a mechanical energy flux of 500 W m-2 upward. Our result supports the notion that shocks dominate the heating of the upper chromosphere, and probably the corona as well, at least in intranetwork regions of the quiet sun.

• 한국환경보건학회지
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• 제3권1호
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• pp.4-8
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• 1976

Authors investigated the hematological examinations of 993 persons at rural region among the 1,7 41 of residents in-the part of Dang Jin (M:268, F:247) and Young Joo (M:270, F:208) in the Korea which was indicated as follows. 1. Average value and standard deviation of hematological items represents as follows: i) Hemoglobin Men Dang Jin-13.99$\pm$0.52. Man Young Joo-14.93$\pm$0.57 Women Dang Jin-12.56$\pm$0.38 women Young Joo-13.65$\pm$0.48 ii)Hematocrit Men Dang Jin-42.68$\pm$1.09 Man Young Joo-44.61$\pm$1.42 Women Dang Jin-38.16$\pm$0.93 women Young Joo-40.33$\pm$1.27 iii) Mean Corpuscular hemoglobin concentration Men Dang Jin-32.79$\pm$1.06. Man Young Joo-33.46$\pm$0.36 Women Dang Jin-32.92$\pm$0.75 women Young Joo-33.83$\pm$0.82 iv) WBC Men Dang Jin-7.130$\pm$880. Man Young Joo-7.490$\pm$910 Women Dang Jin-6.030$\pm$1.150 women Young Joo-7.320$\pm$1.040 2. The aspect of blood type at Young Joo and Dang Jin was same indicated in the order of A,O,B, and AB. 3. There are higher values of hemoglobin, hernatocrit, M.C.H.C. and WBC in men and women at Young Joo than Dang Jin.

• Molecules and Cells
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• 제37권1호
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• pp.43-50
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• 2014

Jumonji domain-containing proteins (JMJD) catalyze the oxidative demethylation of a methylated lysine residue of histones by using $O_2$, ${\alpha}$-ketoglutarate, vitamin C, and Fe(II). Several JMJDs are induced by hypoxic stress to compensate their presumed reduction in catalytic activity under hypoxia. In this study, we showed that an H3K27me3 specific histone demethylase, JMJD3 was induced by hypoxia-inducible factor (HIF)-$1{\alpha}/{\beta}$ under hypoxia and that treatment with Clioquinol, a HIF-$1{\alpha}$ activator, increased JMJD3 expression even under normoxia. Chromatin immunoprecipitation (ChIP) analyses showed that both HIF-$1{\alpha}$ and its dimerization partner HIF-$1{\beta}$/Arnt occupied the first intron region of the mouse JMJD3 gene, whereas the HIF-$1{\alpha}/{\beta}$ heterodimer bound to the upstream region of the human JMJD3, indicating that human and mouse JMJD3 have hypoxia-responsive regulatory regions in different locations. This study shows that both mouse and human JMJD3 are induced by HIF-1.

• 천문학회지
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• 제36권4호
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• pp.271-282
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• 2003

We present results of a $H^{13}CN$ J=1-0 mapping survey of molecular clouds toward the Galactic Center (GC) region of $-1.6^{\circ}{\le}{\iota}{\le}2^{\circ}$ and $-0.23^{\circ}{\le}b{\le}0.30^{\circ}$ with 2' grid resolution. The $H^{13}CN$ emissions show similar distribution and velocity structures to those of the $H^{12}CN$ emissions, but are found to better trace the feature saturated with $H^{12}CN$ (1-0). The bright components among multi-components of $H^{12}CN$ line profiles usually appear in the $H^{13}CN$ line while most of the dynamically forbidden, weak $H^{12}CN$ components are seldom detected in the $H^{13}CN$ line. We also present results of other complementary observations in $^{12}CO$ (J=1-0) and $^{13}CO$ (J=1-0) lines to estimate physical quantities of the GC clouds, such as fractional abundance of HCN isotopes and mass of the GC cloud complexes. We confirm that the GC has very rich chemistry. The overall fractional abundance of $H^{12}CN$ and $H^{13}CN$ relative to $H_2$ in the GC region is found to be significantly higher than those of any other regions, such as star forming region and dark cloud. Especially cloud complexes nearer to the GC tend to have various higher abundance of HCN. Total mass of the HCN molecular clouds within $[{\iota}]{\le}6^{\circ}$ is estimated to be ${\~}2 {\times}10^7\;M_{\bigodot}$ using the abundances of HCN isotopes, which is fairly consistent with previous other estimates. Masses of four main complexes in the GC range from a few $10^5$ to ${\~}10^7\;M_{\bigodot}$ All the HCN spectra with multi-components for the four main cloud complexes were investigated to compare the line widths of the complexes. The largest mode (45 km $s^{-1}$) of the FWHM distributions among the complexes is in the Clump 2. The value of the mode tends to be smaller at the farther complexes from the GC.

• Journal of Radiation Protection and Research
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• 제30권4호
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• pp.237-245
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• 2005

원자력발전소의 가상사고 시나리오를 도입하여 영광 원전 주변 지역에서 가상사고 시에 발생하는 핵종 방출 후 토양 또는 농작물에서 시간 경과에 따라 변화하는 핵종 농도분포를 GIS와 연계하여 표현하고자 하였다. 표현 대상 및 방출핵종은 영광 주변지역의 토양과 $^{137}Cs$로 정하였다. 영광원전 중심 반경 30km 이내 지역을 1km 거리 단위로 총 480개의 16방위 cell로 나누어 준비한 다음, ECOREA-II 코드를 통해 계산된 $^{137}Cs$의 침적량 자료를 ArcView의 polygon cell에 대한 속성 자료에 각각의 cell id와 일치시켜 연결 작업을 수행하였다. 원전에서의 핵종 방출 후 시간이 경과됨에 따라 낮아지는 $^{137}Cs$ 농도값을 일관성있는 색상 변화로 나타내기 위해 ArcView의 color lamp에 대한 RGB 값을 조절하였다. 이 방법을 통하여 $^{137}Cs$의 침적 후 영광주변 반경 30km 지역에서 시간에 따라 변하는 $^{137}Cs$ 농도분포를 쉽게 구분할 수 있도록 나타낼 수 있었다.

• 한국식품영양과학회지
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• 제34권4호
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• pp.496-502
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• 2005

대표적인 유자 산지인 남해(I, II), 통영 및 고흥에서 유자를 구입하여 과육 및 과피로 각각 분리한 후 이화학적 성분 및 아질산염 소거능을 측정하였다. 4종의 유기산이 검출되었으며, citric acid의 함량은 $10.2\pm0.14\~17.7\pm0.17\pm0.17\;g/100g$이었으며, 고흥산 유자의 과육 및 과피에서 각각 $17.3\pm0.16\;g/100g,\;17.7\pm0.17\;g/100g$으로 가장 높게 정량되었다. 무기물은 산지에 따른 차이가 작았으며, 칼륨의 함량이 $1,332.4\pm2.31\~2,308.5\pm3.25\;mg/100g$으로 가장 높았다. 유리아미노산 은 proline, asparagine, glutamic acid가 비교적 높게 함유되어 있었으며 통영산 유자 과피에서 총 326.9 mg/100 g으로 가장 높게 정량되었다. 유자 착즙액의 전자공여능은 시료액의 농도가 증가함에 따라 상승하였으며 $0.1\~0.2\%$ 농도의 산지별 시료액 첨가시 $80.0\%$ 이상의 효과가 나타났다. SOD 유사활성은 $0.01\~0.2\%$의 시료농도에서 $10.2\pm0.50\~20.1\pm0.77\%$였다. 아질산염 소거능은 pH 1.2에서 $0.1\~0.2\%$시료액 첨가구에서 모두 $73\%$이상의 아질산염 소거능을 나타내었으나, pH 4.2에서는 모든 시료액 첨가구에서 $27\%$ 이하로 낮았다.

• Journal of Astronomy and Space Sciences
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• 제22권4호
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• pp.419-430
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• 2005

이 연구에서는 지자기 폭풍의 주상 기간 동안 발생하는 태양풍 동압력 펄스에 대한 통계적 분석을 하였다. 이를 위해 먼저 1997년부터 2001년까지 5년간의 기간으로부터 지자기 폭풍 지수인 Dst 값이 -50nT 이하인 지자기 폭풍을 모두 111개 얻었다. 이러한 지자기 폭풍의 주상기간 동안에 발생한 태양풍 동압력 펄스를 정확히 조사하기 위해 태양풍 자료 뿐만 아니라 지구 저위도 여러 관측소에서 관측된 지자기 수평 성분 H값을 이용하였다. 즉 동압력 펄스가 자기권에 충돌하면 저위도 H 값이 전 지구적인 증가를 보여야 한다는 사실을 이용하였다. 이러한 과정을 통해 얻은 통계적 결과는 다음과 같다. 첫째, 자기 폭풍 중에 발생하는 H의 증가는 평균적으로 그 크기가 자기 폭풍의 강도와 비례하는 경향을 보인다. 이는 강한 자기폭풍일 수록 강한 태양풍 펄스를 동반한다는 것이다. 둘째로 자기폭풍 중에 발생하는 동압력 펄스의 발생 빈도 역시 자기 폭풍의 강도와 비례한다. 셋째, 동압력 펄스 발생 빈도가 0.4회/hr 이상인, 즉 2.5시간에 1회 이상의 동압력 펄스를 동반하는, 지자기 폭풍은 여기서 다루어진 전체 지자기 폭풍 중 약 $30\%$를 차지한다. 2.5시간은 서브스톰의 평균 지속 시간으로 볼 수 있으며, 따라서 자기 폭풍중에 서브스톰이 연속적으로 발생하는 것 만큼 자주 동압력 펄스가 나타나는 자기폭풍이 전체의 $30\%$라는 것이다. 한편 이러한 동압력 펄스의 기원을 이해하기 위해 먼저 지자기 폭풍 유도체에 대해 조사하였다. 그 결과 여기서 다루어진 지자기 폭풍의 약 $65\%$가 CME(Coronal Mass Ejection)에 의해 발생되었고 CIR(Corotating Interaction Regions)과 Type II bursts에 의해 발생한 것이 각각 6.3, $7.2\%$인 것으로 나타났다. 그런데 CME에 의해 발생된 지자기폭풍 중에서 $70\%$ 이상이 그 주상 기간이 CME와 충격파 사이의 공간인 sheath 영역 혹은 CME 앞부분에 해당되는 것으로 나타났다. 따라서 이들 지자기폭풍 주상기간에 빈번히 발생하는 동압력 펄스는 CME와 충격파 사이의 sheath 영역, 그리고 CME 앞부분 영역에서의 빈번한 태양풍 밀도 증가에 기인하는 것으로 보인다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.155-160
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• 2008

Several studies have reported quantitative trait loci (QTL) for meat quality on porcine chromosome 2 (http://www.animalgenome.org/QTLdb/pig.html). For application of the molecular genetic information to the pig industry through marker-assisted selection, single nucleotide polymorphism (SNP) markers were analyzed by comparative re-sequencing of polymerase chain reaction (PCR) products of 13 candidate genes with DNA from commercial pig breeds such as Berkshire, Yorkshire, Landrace, Duroc and Korean Native pig. A total of 34 SNPs were identified in 15 PCR products producing an average of one SNP in every 253 bp. PCR restriction fragment length polymorphism (RFLP) assays were developed for 11 SNPs and used to investigate allele frequencies in five commercial pig breeds in Korea. Eight of the SNPs appear to be fixed in at least one of the five pig breeds, which indicates that different selection among pig breeds might be applied to these SNPs. Polymorphisms detected in the PTH, CSF2 and FOLR genes were chosen to genotype a Berkshire-Yorkshire pig breed reference family for linkage and association analyses. Using linkage analysis, PTH and CSF2 loci were mapped to pig chromosome 2, while FOLR was mapped to pig chromosome 9. Association analyses between SNPs in the PTH, CSF2 and FOLR suggested that the CSF2 MboII polymorphism was significantly associated with several pork quality traits in the Berkshire and Yorkshire crossed F2 pigs. Our current findings provide useful SNP marker information to fine map QTL regions on pig chromosome 2 and to clarify the relevance of SNP and quantitative traits in commercial pig populations.