• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.32.2-32.2
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• 2020

Massive Compact Elliptical Galaxies (MCEGs) found in the local universe are as massive as normal galaxies but extremely compact (M∗ > 1011 Msun, Reff < 1.5 kpc). They are considered to be the relics of red nugget galaxies found at high redshift. They are not likely to have undergone many mergers, keeping their original mass and size. Moreover, it is expected that they host a dominant population of red (metal-rich) globular clusters rather than blue (metal-poor) ones. Indeed, Beasley et al. (2018) found that the color distribution of the cluster system of NGC 1277 is unimodal, showing only a red population. However, NGC 1277 is the only case whose cluster system was studied among MCEGs. In this study, we investigate globular cluster systems of 14 nearby MCEGs with a homogeneous data set of HST/WFC3 F814W/F160W archive images. We detect tens to hundreds of globular clusters in each galaxy and examine their color distributions. Surprisingly, the fractions of red globular clusters are similar to those of normal galaxies, and are much lower than that of NGC 1277. We additionally obtain Gemini/GMOS-N g'r'i' images of PGC 70520, one of the 14 nearby MCEGs, to detect more globular clusters from deeper and wider images. We will discuss the results from the Gemini data combined with the results from the HST data in relation with the formation of MCEGs.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.1-11
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• 2023

In this paper, instead of using recurrent neural network, we compare a classification performance of time series imaging algorithms using convolution neural network. There are traditional algorithms that imaging time series data (e.g. GAF(Gramian Angular Field), MTF(Markov Transition Field), RP(Recurrence Plot)) in TSC(Time Series Classification) community. Furthermore, we compare STFT(Short Time Fourier Transform) algorithm that can acquire spectrogram that visualize feature of voice data. We experiment CNN's performance by adjusting hyper parameters of imaging algorithms. When evaluate with GunPoint dataset in UCR archive, STFT(Short-Time Fourier transform) has higher accuracy than other algorithms. GAF has 98~99% accuracy either, but there is a disadvantage that size of image is massive.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.10
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• pp.753-762
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• 2019

It is very important to use the raw material in a particular field of research or education. Research without raw materials are difficult to prove and often remain hypothesis. The use of the raw material is also important in area studies that study specific areas. However, research of area studies, especially Western history, raw material and historical archives are very important data, but it is difficult to obtain and refer to these data due to physical or spatial constraints. In order to solve this problem, there is a method of collecting and providing historical archives, but it is currently difficult to find a case of providing overseas historical archives as a web system in Korea. Accordingly, in this paper proposes the necessity of collecting historical archives, the method of collection, and the method of digital archiving of collected data structurally and systematically. In this regard, investigate the existing research cases on the archive system and database design, and it description the differentiation between the existing systems and the modeling method proposed in this study. Also, to improve the efficiency of the search, it proposes a method of adding a tag table when database modeling.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.3
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• pp.379-392
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• 2024

With the rapid increase in data, saving storage space and improving the efficiency of data transmission have become critical issues, making the research on the efficiency of data compression technologies increasingly important. Lossless algorithms can precisely restore original data but have limited compression ratios, whereas lossy algorithms provide higher compression rates at the expense of some data loss. There has been active research in data compression using deep learning-based algorithms, especially the autoencoder model. This study proposes a new side-channel analysis data compressor utilizing autoencoders. This compressor achieves higher compression rates than Deflate while maintaining the characteristics of side-channel data. The encoder, using locally connected layers, effectively preserves the temporal characteristics of side-channel data, and the decoder maintains fast decompression times with a multi-layer perceptron. Through correlation power analysis, the proposed compressor has been proven to compress data without losing the characteristics of side-channel data.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.90.1-90.1
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• 2015

Almost hot-Super Earths ($R_p$~1 to $4R_{earth}$ orbital period < 100 days) are around Sun-like stars. But our solar system does not have hot-Super Earth. Andre et al. 2015 has explained this phenomenon by that Jupiter blocks migration of super earth. We have found a multi-planetary system KOI-94 with exo-Jupiter and hot-Super Earth from NASA exoplanet archive data (http://exoplanetarchive.ipac.caltech.edu). In this study, within multi-planetary systems including hot-Super Earth, we compared those with and without exo-Jupiter using their host star and exoplanet parameters, such as metallicity [Fe/H], $T_{eff}$ and $R_*/R_p$.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.407-410
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• 2005

We used a series of Landsat images acquired from 1984 to 2001 to observe decadal changes of the research forest of Kangwon National University. Tree NDVI images of November in 1984, 1986 and 2001 were displayed in RGB color composite. This image enabled us to identify historical change of conifer types and their approximate ages. Conifers were classified into 'old conifer aged more than 25 years', 'young conifer aged 20-25 years' 'very young conifer aged less than 20 years', and recently deforested areas. The results coincide with in situ data very well. Archives of higher resolution images should be used to monitor the change of area for various tree types.

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.71-79
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• 2009

Based on investigation of archive collections of A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and O.A. Scarlato Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. The fourth part of the Review includes 46 species of Heterobranchia (Allogastropoda, Opistobranchia, and Pulmonata). Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.301-306
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• 2004

The purpose of this study is to supply basic data for distinction of Support and Infill in Open Housing. This study is based on archive survey and actual investigation through visiting four sites in Japan, which are experimental SI(skeleton & infill) housings. We found a lot of distinction techniques and methods applied to the SI housings, and findings are applicable to the planning and designing works of apartment housings. Based on the theoretical Studies concerning the distinction and separation of SI housing, this study made out interface map for separation and distinction of housing components and examined a design method of separation accordingly.

• Asian Journal for Public Opinion Research
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• v.1 no.2
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• pp.147-150
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• 2014

Mixed-mode (or multi-mode) surveys and (volunteer) web panels were recently introduced as ways to cope with changes in the social survey environment, which is going through a rapid and massive transformation. The direction, speed, and magnitude of these changes have been clear in Korea, too. Enumerated in Figure 1 are the social surveys between 1960 and 2010 archived by the Korean Social Science Data Archive (KOSSDA) 2. The left panel shows the exponential growth in the overall volume. The other two panels, more importantly, show the changes in the composition. Mixed-mode and online surveys are rapidly increasing their shares and are fast becoming de facto standards in Korea, as in many other countries.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.146.2-146.2
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• 2011

In this study, we have derived the abundances of several elements ? Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni - for the six F G K type stars in IC 2391 and the seven stars in NGC 6475. The spectra of those stars are taken from UVES POP archive data, of which resolution is 80,000. To derive the abundances of those elements, TAME (Tools for Automatic Measurement of Equivalent-widths), Kurucz stellar atmospheric model, and MOOG code are used. The stellar parameters (effective temperature, log g, metallicity, microturbulent velocity) are determined from the iron lines. The results provide the abundance differences of chemical elements between two open clusters, IC 2391 (a member of Gould Belt) and NGC 6475 (non-member of it), which would lead to better understanding about Gould Belt.