• Publications of The Korean Astronomical Society
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• v.30 no.1
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• pp.31-38
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• 2015

We develop a real-time data transfer system for the Korea Microlensing Telescope Network (KMTNet) photometry data and test whether it is suitable for Korea Astronomy and Space Science Institute (KASI) and three different observatories, which are Cerro Tololo Inter-Ameriacan Observatory (CTIO) in Chile, Siding Springs Observatory (SSO) in Australia, and South African Astronomical Observatory (SAAO) in South Africa. For this test, we use a high speed global network being dedicated for researches. From the test, we obtain that the elapsed times between KASI and each three observatories, CTIO, SSO, and SAAO to transfer 650 MB of data are 99.0, 9.2, 119.0 seconds, respectively. This means that the system can be used for the real-time data processing of KMTNet.

• Asian Journal of Innovation and Policy
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• v.3 no.1
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• pp.72-93
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• 2014

This study analyzed the factors that influence the research productivity of 236 graduate students who are funded by the Global Ph.D. Fellowship Program of the National Research Foundation of Korea. Research productivity was measured by the number of SCI publications, and the explanatory factors are the demographic factor, the financial factor, the reputation of institutions and the supervisor factor. This study included 2 indices such as the reputation of institutions and the research productivity of supervisors to check the halo effect unlike other studies. Results are as follows: 1) no gender difference, 2) better performance by younger age group, 3) no difference even if the students are additionally funded by other research support programs, 4) no halo effect by the reputation of institution but rather better performance from low ranked universities, 5) and a positive halo effect by supervisors.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.473-474
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• 2015

Halo merger trees are the essential backbone of semi-analytic models for galaxy formation and evolution. Srisawat et al. (2013) show that different tree building algorithms can build different halo merger histories from a numerical simulation for structure formation. In order to understand the differences induced by various tree building algorithms, we investigate the impact of halo merger trees on a semi-analytic model. We find that galaxy properties in our models show differences between trees when using a common parameter set. The models independently calibrated for each tree can reduce the discrepancies between global galaxy properties at z=0. Conversely, with regard to the evolutionary features of galaxies, the calibration slightly increases the differences between trees. Therefore, halo merger trees extracted from a common numerical simulation using different, but reliable, algorithms can result in different galaxy properties in the semi-analytic model. Considering the uncertainties in baryonic physics governing galaxy formation and evolution, however, these differences may not necessarily be significant.

• Wind and Structures
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• v.1 no.2
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• pp.145-160
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• 1998

In recent years, the effects of a possible climate change have been discussed in regard to wind loading on buildings and structures. Simple scenarios based on the assumption of global warming suggest an increase of storm intensities and storm frequencies and a possible re-distribution of storm tracks. Among recent publications, some papers seem to verify these scenarios while others deny the influence of climatic change. In an introductory step, the paper tries to re-examine these statements. Based on meteorological observations of a weather station in Germany, the existence of long-term trends and their statistical significance is investigated. The analysis itself is based on a refined model for the wind climate introducing a number of new basic variables. Thus, the numerical values of the design wind loads used in modern codes become more justified from the probabilistic point of view.

• Journal of Information Science Theory and Practice
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• v.5 no.2
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• pp.33-47
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• 2017

The aim of the present study is to analyze the present state and evolution of scientific research with regard to the scientific production generated on Facebook. Good analysis proves challenging due to the large number of publications about the topic. That is why we concentrate on Scopus as the information service with the highest coverage on this topic. We performed a bibliometric analysis on Facebook-related research from 2005 to 2016. We identified publication output, subject areas, journals, and countries in order to assess the publication trends and research hotspots in this field. Moreover, an author network graph and a geo map were applied to visualize some research trends. These results provide a basis for better understanding of the development of global Facebook research.

• Journal of Information Science Theory and Practice
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• v.2 no.1
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• pp.35-47
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• 2014

Korean researchers' scientific outputs are increasing rapidly with the growth of both Korea's economy and industry size. This is the time to analyze the scientific output (STEM area) of Korea over the last 40 years. For this analysis, this study used the SCIE database of Web of Science (WoS), which is a representative global Citation Index Service. The objects of analysis are every Korean document published in the SCIE journal, and the research scopes are (1) analysis of citation and subject categories and (2) analysis of co-authorship. Through this study, characteristics such as cited trend and research trend by subject, and the status of collaboration between Korea and other countries including the 50 states of the USA were revealed.

• Journal of Information Technology Applications and Management
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• v.31 no.1
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• pp.139-161
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• 2024

The Fourth Industrial Revolution has spurred widespread adoption of AI-based services, driving global interest in AI semiconductors for efficient large-scale computation. Text mining research, historically using LDA, has evolved with machine learning integration, exemplified by the 2021 BERTopic technology. This study employs BERTopic to analyze AI semiconductor-related patents and research data, generating 48 topics from 2,256 patents and 40 topics from 1,112 publications. While providing valuable insights into technology trends, the study acknowledges limitations in taking a macro approach to the entire AI semiconductor industry. Future research may explore specific technologies for more nuanced insights as the industry matures.

• Journal of Korea Trade
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• v.24 no.8
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• pp.19-38
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• 2020

Purpose - The Korean government has been promoting the New Southern Policy (NSP) prior to the onset of the COVID-19 pandemic, which damage global value chain (GVC). The purpose of this paper is to emphasize that the NSP should be developed to provide tangible support in corporate GVC adjustment, away from diplomatic activities in order to offset GVC losses due to COVID-19 and expand export capabilities. Design/methodology - Two research methodologies are combined for this paper: A computational general equilibrium (CGE) model is used to estimate the impacts of the COVID-19 pandemic and NSP on Korea's exports, and the decomposition methodology (Wang, Wei and Zhu, 2013) to evaluate the stability of GVC. The conventional CGE model was modified to obtain an estimate for decomposition. The research methodology adopted in this study was attempted for the first time, and it can be widely used in future GVC research. Findings - Results found the effects of COVID-19 reduced Korea's total exports by 27% and GVC by more than 30%. In particular, VA in Korea's exports to the NSP region was found to have a huge impact in heavy industries and textiles, and its exports to Vietnam seemed to suffer the largest loss in GVC among ASEAN countries. If the NSP is implemented properly, it appears that it could offset much of the negative impacts of COVID-19, implying the importance of the effectiveness of the NSP. Originality/value - Many papers have assessed the NSP descriptively, and the GVC has been a topic for many publications. However, the impact of COVID-19 on Korea's GVC with the NSP countries has not been quantitatively studied. This paper emphasizes that the NSP should be pursued based on the results of quantitative analysis. In addition, the research methodology of this paper can be used for other GVC research with relevant modifications.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.155-162
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• 2022

In this paper, we examined the research trends and characteristics related to the metaverse in global journals published between 2000 and 2022 from the Web of Science database. The analysis included descriptive statistics, multidimensional scaling, keyword network analysis, and visualization. In addition, semantic network models were constructed, and centrality (betweenness and degree) analysis was performed using R and KH coder in two separate categories based on the trends and aspects of the publication: analysis period 1 (Jan 2000 to Dec 2020) and period 2 (Jan 2021 to Jun 2022). The results showed that the recent global research trends related to the metaverse could be quantitatively characterized using the semantic network analysis. Also, the results could be applied to suggest future research topics in the field of metaverse based on quantitative and empirical data.

• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.1-13
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• 2000

Through the coupling between the near-earth space environment and the polar ionosphere via geomagnetic field lines, the variations occurred in the magnetosphere are transferred to the polar region. According to recent studies, however, the polar ionosphere reacts not only passively to such variations, but also plays active roles in modifying the near-earth space environment. So the study of the polar ionosphere in terms of geomagnetic disturbance becomes one of the major elements in space weather research. Although it is an indirect method, ground magnetic disturbance data can be used in estimating the ionospheric current distribution. By employing a realistic ionospheric conductivity model, it is further possible to obtain the distributions of electric potential, field-aligned current, Joule heating rate and energy injection rate associated with precipitating auroral particles and their energy spectra in a global scale with a high time resolution. Considering that the ground magnetic disturbances are recorded simultaneously over the entire polar region wherever magnetic station is located, we are able to separate temporal disturbances from spatial ones. On the other hand, satellite measurements are indispensible in the space weather research, since they provide us with in situ measurements. Unfortunately it is not easy to separate temporal variations from spatial ones specifically measured by a single satellite. To demonstrate the usefulness of ground magnetic disturbance data in space weather research, various ionospheric quantities are calculated through the KRM method, one of the magneto gram inversion methods. In particular, we attempt to show how these quantities depend on the ionospheric conductivity model employed.