• Publications of The Korean Astronomical Society
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• v.39 no.2
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• pp.39-51
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• 2024

Since the division of the Korean Peninsula in 1948, South and North Korea have independently developed their astronomical almanacs: Ryeokseo at the Korea Astronomy and Space Science Institute in South Korea and Cheonmunryeok at the Pyongyang Astronomical Observatory in North Korea. This study compares Ryeokseo and Cheonmunryeok for the year 2015, focusing on publication systems, content, terminology, and differences in data calculation methods. Additionally, it examines the calendars of South and North Korea from 2018 to 2023, analyzing similarities and differences in the representation of calendrical dates, public holidays, and other related aspects. The findings reveal that while the structure and content of the astronomical almanacs are similar in both countries, notable variances exist in the versions of ephemerides, time scales, and calculation precision. Consequently, identical data points are often recorded with slightly different values in each country's almanacs. Furthermore, approximately 28% of the terms used in North Korea's astronomical almanac are either not utilized in South Korea or have different definitions. Regarding calendar systems, those of South and North Korea are largely similar, resulting in no significant discrepancies in dates. However, there are notable differences in the observance of public holidays. While traditional holidays are common to both, most holidays are distinctively celebrated. Notably, North Korea does not observe religious holidays, and many of its holidays are associated with the regime.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.85-86
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• 1996

The imaging spectroscopic observations of the Magellanic irregular galaxy NGC 4449 were made to show the detailed kinematic structure of the galaxy. Many filamentary structures and Several bubble-like structures are recognized in a 3D data cube of H$\alpha$ emission line. Velocity field shows the kpc-scale mosaic structure and counter- rotation of ionized gas.

• Publications of The Korean Astronomical Society
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• v.8 no.1
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• pp.137-151
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• 1993

We have calculated the astronomical almanac 1994 and simulated the trajectory of a satellite orbit considering all perturbative forces with various initial conditions. In this work, Gauss Jackson multistep integration method has been used to calculate our basic equation of motion with high numerical accuracy. It has beer. found that our results agree well with the Astronomical Almanac Data distributed by JPL of NASA and the orbit simulations have been carried out with fast speed, stability and excellent round-off error accumulation, comparing with other numerical methods. In order to be carried out our works on almanac and orbit calculations easily by anyone who uses a personal computer, we have made a computer program on graphical user interface to provide various menus for detail works selected by a mouse.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.39-43
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• 2015

We overview and discuss the IAU today from the viewpoint of its regions based on historical and statistical data, and consider the status and future of astronomy in the Asian-Pacific region. New activities of the IAU, the Office of Astronomy for Development (OAD) and the Office for Astronomy Outreach (OAO) for the future evolution of astronomy are introduced. We also review the recent developments in astronomy in the Asian-Pacific region, and emphasize the importance of regional cooperation and coordination for the future.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.58.1-58.1
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• 2019

We have developed Ground Software (GSW) of BITSE. The ground software includes mission operation software, data visualization software and data processing software. Mission operation software is implemented using COSMOS. COSMOS is a command and control system providing commanding, scripting and data visualization capabilities for embedded systems. Mission operation software send commands to flight software and control coronagraph. It displays every telemetry packets and provides realtime graphing of telemetry data. Data visualization software is used to display and analyze science image data in real time. It is graphical user interface (GUI) and has various functions such as directory listing, image display, and intensity profile. The data visualization software shows also image information which is FITS header, pixel resolution, and histogram. It helps users to confirm alignment and exposure time during the mission. Data processing software creates 4-channel polarization data from raw data.

• Publications of The Korean Astronomical Society
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• v.27 no.1
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• pp.1-16
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• 2012

In this paper, we describe the installation of VLBI Correlation Subsystem (VCS) main product and its performance at the Korea-Japan Correlation Center (KJCC). The VCS main product was installed at KJCC in August 2009. For the overall performance evaluation of VCS, playbacks, Raw VLBI Data Buffer (RVDB) system, and Data Archive (DA) system were installed together. The VCS main product was connected between RVDB and DA, and the correlation results were put into the DA to confirm the normal operation of VCS 16 station mode configuration. The evaluation test was first performed with 4 station mode, same as the factory test of VCS main product. Based on the results of 4 station mode, the same evaluation test was conducted for 16 station mode of VCS. We found that the correlation results of VCS were almost similarly compared to those of the Mitaka FX Correlator. Through the test results, we confirmed that the problems such as spectrum errors, delay parameter processing module and field programmable gate array errors in antenna unit, which were generated at the factory test of VCS main product, were clearly solved. And we verified the performance and connectivity of VCS by obtaining the expected correlation results and we also confirmed that the performance of VCS was sufficient for real VLBI observation data in both 4 and 16 station modes.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.11-15
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• 2017

We present the AKARI far-infrared (FIR) all-sky maps and describe its characteristics, calibration accuracy and scientific capabilities. The AKARI FIR survey has covered 97% of the whole sky in four photometric bands, which cover continuously 50-180 micron with band central wavelengths of 65, 90, 140, and 160 microns. The data have been publicly released in 2014 (Doi et al., 2015) with improved data quality that have been achieved since the last internal data release (Doi et al., 2012). The accuracy of the absolute intensity is ${\leq}10%$ for the brighter regions. Quantitative analysis of the relative intensity accuracy and its dependence upon spatial scan numbers has been carried out. The data for the first time reveal the whole sky distribution of interstellar matter with arcminute-scale spatial resolutions at the peak of dust continuum emission, enabling us to investigate large-scale distribution of interstellar medium in great detail. The filamentary structure covering the whole sky is well traced by the all-sky maps. We describe advantages of the AKARI FIR all-sky maps for the study of interstellar matter comparing to other observational data.

• The Bulletin of The Korean Astronomical Society
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• v.25 no.2
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• pp.110-110
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• 2000

• The Bulletin of The Korean Astronomical Society
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• v.24 no.2
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• pp.121-121
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• 1999

• The Bulletin of The Korean Astronomical Society
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• v.33 no.1
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• pp.57.2-57.2
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• 2008