The Korean Astronomical Society (KAS) Education & Public Outreach Committee has provided education services for children and school teachers in Cambodia over the past three years from 2016 to 2018. In the first year, 2016, one KAS member visited Pusat to teach astronomy to about 50 children, and in the following two years of 2017 and 2018, three and six KAS members, respectively, executed education workshops for ∼ 20 (per each year) local school teachers in Sisophon. It turned out that it is desirable to include both teaching of astronomical knowledge and making experiments and observations in the education in order for the program to be more effective. Language barrier was the main obstacle in conveying concepts and knowledge, and having a good interpreter was very important. It happens that some languages, such as the Khmer of Cambodia, do not have astronomical terminologies, so that lecturers and even the education participants together are needed to communicate and create appropriate words. Handout hardcopies of the education materials (presentation files, lecture/experiment summaries, terminologies, etc.) are extremely helpful for the participants. Actual performing of assembling and using astronomical telescopes for night sky observations has been lifetime experience for some of the participants, which might promote zeal for knowledge and education. It is hoped that these education services for developing countries like Cambodia can be regularly continued in the future, and further extended to other countries such as Laos and Myanmar.

We present a BV I optical photometric study of the old open cluster Ruprecht 6 using the data obtained with the SMARTS 1.0 m telescope at the CTIO, Chile. Its color-magnitude diagrams show the clear existence of the main-sequence stars, whose turn-o point is located around V  18:45 mag and B - V  0:85 mag. Three red clump (RC) stars are identied at V = 16:00 mag, I = 14:41 mag and B - V = 1:35 mag. From the mean Ks-band magnitude of RC stars (Ks = 12:39  0:21 mag) in Ruprecht 6 from 2MASS photometry and the known absolute magnitudes of the RC stars (MKS = - :595  0:025 mag), we obtain the distance modulus to Ruprecht 6 of (m -M)0 = 13:84  0:21 mag (d = 5:86  0:60 kpc). From the (J - Ks) and (B - V ) colors of the RC stars, comparison of the (B - V ) and (V - I) colors of the bright stars in Ruprecht 6 with those of the intrinsic colors of dwarf and giant stars, and the PARSEC isochrone ttings, we derive the reddening values of E(B - V ) = 0:42 mag and E(V - I) = 0:60 mag. Using the PARSEC isochrone ttings onto the color-magnitude diagrams, we estimate the age and metallicity to be: log(t) = 9:50  0:10 (t = 3:16  0:82 Gyr) and [Fe/H] = -0:42  0:04 dex. We present the Galactocentric radial metallicity gradient analysis for old (age > 1 Gyr) open clusters of the Dias et al. catalog, which likely follow a single relation of [Fe/H] = (-0:034  0:007)RGC + (0:190  0:080) (rms = 0.201) for the whole radial range or a dual relation of [Fe/H] = (-0:077  0:017)RGC + (0:609  0:161) (rms = 0.152) and constant ([Fe/H]  -0:3 dex) value, inside and outside of RGC  12 kpc, respectively. The metallicity and Galactocentric radius (13:28  0:54 kpc) of Ruprecht 6 obtained in this study seem to be consistent with both of the relations.

We search for misclassified type 1 AGNs among type 2 AGNs identified with emission line flux ratios, and investigate the properties of the sample. Using 4 113 local type 2 AGNs at 0.02 < z < 0.05 selected from Sloan Digital Sky Survey Data Release 7, we detected a broad component of the Hα line with a Full-Width at Half-Maximum (FWHM) ranging from 1 700 to 19 090 km s−1 for 142 objects, based on the spectral decomposition and visual inspection. The fraction of the misclassified type 1 AGNs among type 2 AGN sample is 3.5%, implying that a large number of missing type 1 AGN population may exist. The misclassified type 1 AGNs have relatively low luminosity with a mean broad Hα luminosity, log LHα = 40.50 ± 0.35 erg s−1, while black hole mass of the sample is comparable to that of the local black hole population, with a mean black hole mass, log MBH = 6.94 ± 0.51 M⊙. The mean Eddington ratio of the sample is log Lbol/LEdd = −2.00±0.40, indicating that black hole activity is relatively weak, hence, AGN continuum is too weak to change the host galaxy color. We find that the Oiii lines show significant velocity offsets, presumably due to outflows in the narrow-line region, while the velocity offset of the narrow component of the Hα line is not prominent, consistent with the ionized gas kinematics of general type 1 AGN population.

This study was carried out to investigate the effects of stocking density on eating and ruminating behavior of Hanwoo steers (Bos taurus coreanae) in the finishing period. A total of 30 finishing Hanwoo steers (631.3 ± 11.4 kg, 25 months old) were allocated to one of four stocking density groups comprising 1, 2, 3, and 4 steers per 32 m2 pen [G1 (32 m2), G2 (16 m2), G3 (10.7 m2) and G4 (8 m2), respectively] in triplicate. Eating, rumination behaviors, as well as dry matter intake of steers were measured, and the results were subjected to analysis of variance with stocking density as the main effect. The results of eating behaviors over 48 hours are summarized as follows: Total intake was significantly (p<0.01) higher in G1, G2, and G3 compared to G4. Eating time was not different among the treatments, whereas ruminating time increased in the order of G1 > G2 > G3 > G4 (p<0.01). However, resting time and chewing time (sum of eating and ruminating) were not significantly different among the treatments. Number of boluses and number of total chews were highest in G1 (p<0.01), whereas number of chews per bolus was highest in G3 (p<0.01). Ruminating time per bolus as well as number of boluses per minute was not significantly different among the treatments. Number of defecations was higher in G1 and G2 animals compared to G3 and G4 animals (p<0.01). However, stocking density had no effect on drinking or urination. In conclusion, increasing stocking density (i.e. G4) per pen decreased voluntary intake, ruminating time, and total chewing number in the finishing period of Hanwoo steers. However, care must be taken in discussing stocking density in the present study as the space allowance per animal was satisfactory to meet the current animal welfare regulation in Korea and in Europe, although the beef production system in Korea is more intensive than in Europe.

We present an analysis of the papers published in the journals Nature and Science in the years from 2006 to 2010. During this period, 7788 papers in total were published in the two journals. This includes 544 astronomy papers that correspond to 7.0% of the papers in 'all' research fields and 18.9% of those in the field of 'physical sciences'. The sub-fields of research of the astronomy papers are distributed, in a descending order of the number of papers, in Solar System, stellar astronomy, galaxies and the universe, the Milky Way Galaxy, and exoplanets. The observational facilities used for the studies are mainly ground-based telescopes (31.1%), spacecrafts (27.0%), and space telescopes (22.8%), while 16.0% of papers did not use any noticeable facilities and 1.7% used other facilities. Korean scientists have published 86 papers (33 in Nature and 53 in Science), which is 1.10% of all the papers (N = 7788) in the two journals. The share of papers by Korean astronomers among the scientific papers by Koreans is 8.14%, slightly higher than the contribution of astronomy papers (7.0%) in both journals.

We present UBV I photometry of the old open cluster NGC 1193. Color-magnitude diagrams (CMDs) of this cluster show a well defined main sequence and a sparse red giant branch. For the inner region of r < 50′′, three blue straggler candidates are newly found in addition to the objects Kaluzny (1988) already found. The color-color diagrams show that the reddening value toward NGC 1193 is E(B − V ) = 0.19 ± 0.04. From the ultraviolet excess measurement, we derived the metallicity to be [Fe/H]= −0.45 ± 0.12. A distance modulus of (m −M)0 = 13.3 ± 0.15 is obtained from zero age main sequence fitting with the empirically calibrated Hyades isochrone of Pinsonneault et al. (2004). CMD comparison with the Padova isochrones by Bertelli et al. (1994) gives an age of log t = 9.7±0.1.

We collected eleven large astronomical catalogues, which include 2MASS, USNO B1.0, GSC 2 catalogues and so on. Most of these catalogues are the frequently used by astronomers for all sorts of applications. But the researches are faced with the problem of accessing these databases because these catalogues contain from tens millions up to thousands of millions of records. So we developed a web application system to manage these large catalogues, the main purpose of the web application is to allow a powerful and efficient querying activity on these catalogues through internet by using a simple web interface. User could retrieve the query result in variety of formats including plain text, HTML, Microsoft Excel format (XLS), and VOTable. Furthermore, user also could display and analyze result graphically by using a powerful interactive visualization tools named VOPlot which was developed by the Virtual Observatory-India (VOI) project.

The First Generation Digitized Sky Survey (DSS-I) is a collection of digitized photographic atlases of the night sky taken from the Palomar Observatory (northen sky) and the Anglo-Australian Observatory (southern sky). DSS-I is widely used by the astronomical community for a number of applications including object cross-identification and astrometry. However, accessing and retrieving the actual images are nontrivial owing to the huge size (> 60 GB) of the dataset. To facilitate retrieval process of DSS-I data for the public, Korean Astronomical Data Center (KADC) developed a web application that provides not only data retrieval but also visualization functions. The web application consists of several modules developed using Java Applet, Jave Servlet, and JaveServer Pages (JSP) technologies. It allows users to retrieve images efficiently in various formats such as FITS, JPEG, GIF, and TIFF, and also offers an interactive visulization tool, ImgViewer, for displaying/analyzing FITS images. To use the web application, users require a Java-enabled web browser.

Construction of the Virtual Observatory (VO) is a great concern to the astronomical community in the 21st century. We present an outline of the concept and necessity of the va and the current status of various VO projects including the 15 national ones and the International Virtual Observatory Alliance (IVOA). We summarize the possible science cases that could be solved by using the VO data/tools, real science cases which are the results of using current VO tools, and our own work of using AstroGrid, the United Kingdom national VO, for a research on star formation history of galaxies.

We have constructed a database of Korean historical astronomical records. The database contains observational data recorded from BC 2183 to AD 1910. We have also built a webpage for searching through the database based on the following criteria: (1) dynasties (2) astronomical phenomena (3) reigning kings (4) references (5) keywords. Users may select two or more dynasties to search through the database for a certain phenomena, and compare data with those of other dynasties. The queried data can be primarily sorted by one critetion, and secondarily sorted by another, each in ascending or descending order. The search results give dates both in Solar and Lunisolar calendars, years and dates in Sexagenary cycle, dynasties, reigning kings, astronomical phenomena, and references. The database and webpage were constructed under the research project of the Korean Astronomical Data Center (KADC, http://kadc.kao.re.kr) in Korea Astronomy Observatory (KAO).

Korean Astronomical Data Center (KADC, http://kadc.kao.re.kr) in Korea Astronomy Observatory (KAO) has constructed an archive of Bohyunsan Optical Astronomy Observatory (BOAO) 1.8m telescope data. The archive is consisted of photometric (1KCCD, 2KCCD) and spectroscopic data of 400GB amount for the period of 1997 to 2002,and the first web service is made of the data from 1997 to 2001. In the search page, primary search criterion of object name or coordinates is used. Users can also refine the search criteria using parameters such as observation date, observer(s), data type, and/or instrument. The data identified from the search can be uploaded to the FTP site for further downloading in FITS format. This archive is the first DB of astronomical data made in Korea.

We present a study of the old open cluster Trumpler 5 (Tr 5), based on the CDS archival data. From the color-magnitude diagrams of Tr 5, we have found the positions of main-sequence turn-off (MSTO) and red giant clump (RGC) stars. Using the mean magnitude of the RGC stars, we have estimated the reddening toward Tr 5, E(B - V) = 0.60 ± 0.10. Using the stars common in two data sets and the theoretical isochrones of Padova group, we have estimated the distance modulus Vo - Mv = 12.64 ± 0.20 (d = 3.4 ± 0.3 kpc), the metallicity [Fe/H) = -0.30 ± 0.10, and the age of 2.4 ± 0.2 Gyr (log t = 9.38). These metallicity and distance values are consistent with the relation between the metallicity and the Galactocentric distance of other old open clusters, for which we obtain the slope of Δ[Fe/H]/ Rgc = -0.064 ± 0.010 dex kpc-1.

We present UBVI CCD photometry of the stellar contents and globular cluster(GC) candidates in the spiral galaxy NGC 300 in the Sculptor group. Color-magnitude diagrams for 18 OB associations having more than 30 member stars are presented. The slope of the initial mass function for the bright stars in NGC 300 is estimated to be Γ = -2.6 ± 0.3. Assuming the distance to NGC 300 of (m - M)o = 26.53 ± 0.07, the mean absolute magnitude of three brightest blue stars is obtained to be < MvBSG (3) > = -8.95 mag. We have performed search for GCs in NGC 300 and have found 17 GC candidates in this galaxy. Some characteristics of these GC candidates are discussed.

Foehn damage on rice plant is one of the important abiotic stresses in eastern costal area of Korea. To know the relationship between foehn impact and morphological traits of rice, wind tunnel method was used with 106 rice cultivars. Less influencing traits on foehn were short panicle, large panicle number per hill, thin panicle neck, and the flag leaf of narrow, short and thick. Leaf pubescence reduced the impact on foehn. 'Naepungbyeo' belong-ed to foehn tolerant varietal group, while 'Ansanbyeo' belonged to the opposite group. Three levels of root cutting treatment with two rice cultivars were conducted to evaluate the foehn impact using wind tunnel. The severity of wind damages was followed the sigmoidal curve duration of wind tunnel treatment were prolonged. Different responses of root cutting to wind tunnel treatment could be used to evaluate the severity of the foehn impact. 'Naepungbyeo' was one of the less implausible cultivars on foehn. 'Nae-pungbyeo' showed tolerant response to wind under 21% root removing treat-ment (20㎝ root cutting), however 'Ansanbyeo' was wilted under the same treatment. In case of 35 % root removing treatment(10㎝ root cutting), both rice cultivars failed to alive against foehn wind.