• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.103-111
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• 2021

The purpose of this study is to study a method for preventing collisions of multiple drones in controlled airspace. As a result of the study, it was proved that it is appropriate as a method to control drone collisions after setting accurate information on the ROI (Region of Interest) area estimated based on the expected drone path and time in the control system as a method to avoid drone collision. As a result of the empirical analysis, the diameter of the flight path of the operating drone should be selected to reduce the risk of collision, and the change in the departure time and operating speed of the operating drone did not act as an influencing factor in the collision. In addition, it has been demonstrated that providing flight priority is one of the appropriate methods as a countermeasure to avoid collisions. For collision avoidance methods, not only drone sensor-based collision avoidance, but also collision avoidance can be doubled by monitoring and predicting collisions in the control system and performing real-time control. This study is meaningful in that it provided an idea for a method for preventing collisions of multiple drones in controlled airspace and conducted practical tests. This helps to solve the problem of collisions that occur when multiple drones of different types are operating based on the control system. This study will contribute to the development of related industries by preventing accidents caused by drone collisions and providing a safe drone operation environment.

• Journal of Science Education
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• v.45 no.2
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• pp.231-246
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• 2021

The Korean Ministry of Education has emphasized the convergent ability for human resource cultivating the development of science and technology in the future. Based on this, Korean STEAM education aims to enhance students' interest and their understanding of science and technology as well as to develop students' convergence thinking and problem-solving skills. Through the camp for gifted students, students are generally introduced to produce self-directed outputs in order to solve the problem in everyday life. In this study, the author aims to find out whether the gifted high school students' creative leader competency and STEAM literacy changed after they experienced STEAM-based camp. 517 gifted students from 52 high schools in the Metropolitan city region join the camp, which is focused on generating student-centered outputs for problem-solving in daily life context. Before and after the camp, the creative leader competency and the STEAM literacy of participants were tested and compared. From the result, we found that the gifted high school students' creative leader competency and STEAM literacy improved after participating in the STEAM camp. In particular, all the sub-factors except for the social value pursuit domains in the social characteristic area of creative leader competency and the areas of creativity, respect, and communication in STEAM literacy increased. Educational implications will be discussed.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.9
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• pp.243-250
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• 2021

Recently, with the development of cloud computing, interest in database outsourcing is increasing. However, when the database is outsourced, there is a problem in that the information of the data owner is exposed to internal and external attackers. Therefore, in this paper, we propose a parallel range query processing algorithm that supports privacy protection. The proposed algorithm uses the Paillier encryption system to support data protection, query protection, and access pattern protection. To reduce the operation cost of a checking protocol (SRO) for overlapping regions in the existing algorithm, the efficiency of the SRO protocol is improved through a garbled circuit. The proposed parallel range query processing algorithm is largely composed of two steps. It consists of a parallel kd-tree search step that searches the kd-tree in parallel and safely extracts the data of the leaf node including the query, and a parallel data search step through multiple threads for retrieving the data included in the query area. On the other hand, the proposed algorithm provides high query processing performance through parallelization of secure protocols and index search. We show that the performance of the proposed parallel range query processing algorithm increases in proportion to the number of threads and the proposed algorithm shows performance improvement by about 5 times compared with the existing algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.343-353
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• 2021

Historical dramas are changing in response to the public who wants more dramatic development, and historical costumes are also expressed in a modern sense. The purpose of this study is to examine the modernization of historical costumes in historical dramas and how the modernization of historical costumes in historical dramas is fostered from the learner's point of view with suggesting implications. As a result of this study, first, the essential problem with the modernization of historical costumes was the excessive modern transformation that undermines historical facts in historical dramas. Second, the negative perceptions of the modernization of historical costumes in historical dramas included the loss of the unique Korean identity, decreased immersion in drama, and the educational influence of media. Positive perceptions focused on the increased interest through raising awareness of traditional culture, compromises on changes in the times, and increased visual play of the public. Third, the implications of the modernization of historical costumes in historical dramas require the awareness improvement of participants in historical drama and a thorough preliminary investigation by the costume designer on the historical costume, an in-depth study of traditional costumes, a systematic educational approach, viewers' attention, and government effort.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.6
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• pp.681-689
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• 2019

The 46th Davos Forum of the World Economic Forum (WEF) predicts the continued growth of the 4th industry in the future. Currently, the 4th industry is attracting attention in various academic and practical fields. As a core technology of the 4th industry, Big Data is regarded as a major resource to lead the 4th industrial revolution along with artificial intelligence. As the growing interest in Big Data, researches on it are actively being done. However, literature studies on existing Big Data are focused on qualitative research, and quantitative research is insufficient. Therefore, this study aims to analyze the big data research flow in MIS field and to make academic thirst for quantification. This study has collected 145 abstracts of big data papers published in major journals in MIS field and confirmed that a majority of papers are published in Decision Support Systems Journal. Text mining and text network analysis were performed only for DSS journals to eliminate bias. As a result of the analysis, it was found out that researches on combining big data in the management field between 2012 and 2014, and researches on system development and analysis method for using big data from 2015 to 2017 were conducted.

• Journal of Navigation and Port Research
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• v.45 no.6
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• pp.276-283
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• 2021

The capital structure of the shipping business, which is characterized by its capital intensity and extreme market volatility, is closely related to long-term stability. Research in this area has been conducted mostly in the form of deriving the determinants of capital structure from company-wise financial ratios. This research, on the other hand, has a different approach to the topic. It identifies the relationship between actual cash profit and loss and other variables - i.e. actual vessel prices, interest rates and leverage ratio - by employing historical simulation. The result demonstrates that the P anamax cash profit shows 0 (break-even point) when the debt weight reaches 64.38% (debt ratio 180.74%) and the Cape, 73.04% (debt ratio 270.92%). Additionally, the ships of different types show a divided pattern for the pre- and post-'Super Boom'. It indicates that the business area and the market cycle should be considered when a leverage strategy is established. This research benefits shipping companies set a rational leverage strategy as well as delivers a reasonable guideline to government authorities for the development of a sound policy on shipping finance.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.4
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• pp.265-280
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• 2021

Population density due to urbanization is making people interested in underground space development and much interest in TBM construction with low vibration and noise. This led to a lot of research on TBM. However, research on the characteristics of the cutterhead opening of the TBM equipment being occluded under the ground conditions under which it is excavated is insufficient. Accordingly, a study was conducted to investigate clogging of the cutterhead opening during the shield TBM rolling. To identify the clogging of cutterhead openings in SHIELD TBM equipment, the reduced model experiment was divided into clay rate (10%, 30%, 50%, 60%), cutterhead opening rate (30%, 50%, 60%), and cutterhead rotation direction (one-way, two-way) and rotational speed (3 RPM) and conducted in 36 cases. Results of scale model test on shield TBM clogging, it was analyzed that the ground condition containing clay soil increased the clogging effect in both directions than the unidirectional rotation, and that the lower the rotational speed of the cutterhead, the less the clogging effect. Accordingly, the direction of cutterhead rotation, rotational speed and opening rate are calculated by taking into account ground conditions during ground excavation, the clogging effect can be reduced. It is believed to be effective in saving air as the clogging effect is reduced. Therefore, this study is expected to be an important material for domestic use of shield TBM.

• Korea Real Estate Review
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• v.28 no.1
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• pp.105-114
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• 2018

According to Statistics Korea, South Korea has entered the realm of the "aging society" with the rapid development of the country's population. Researchers anticipate that the extremely high (73%) ratio of real estate property to total assets for mid-age to aged households in South Korea that do not have a fixed income may cause serious problems in the future. For example, the real estate market in South Korea may be bombarded with properties listed for sale, causing the average property price to drop due to the abundant supply. Although this prediction may be reasonable, this concept has excluded the idea of pension (which is crucial as it can be considered a consistent and fixed income) due to the limited amount of available data thereon; as such, it is important to include this factor to improve the pertinent research. Thus, this research was conducted using the data from the $3^{rd}$ and $5^{th}$ Korea Retirement and Income Study. For the study results, it was found that variables such as net asset, gender, education, and number of family members have the same impact as that found in the previous studies. To extend from here, two new factors were introduced: the existence of pensions and the amount of pension received by a household. From there, it was found that the existence of a consistent and fixed income such as a pension has led to an increase in housing consumption, the area of interest of the authors.

• International Area Studies Review
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• v.15 no.3
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• pp.263-283
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• 2011

As China has achieved continuous high growth, innovative housing system and rapid growth of housing finance for thirty years since its reforming and opening, Chinese real estate industry has developed rapidly, investment in real estate has increased remarkably and price of real estate has increased continuously. In particular, as China joined WTO in 2001, overseas companies have expanded investment in Chinese real estate market with chances of potential profit. Recently, management of foreign capital real estate companies has expanded from housing to office buildings and luxury shops. Besides, management has expanded from real estate development to various tasks such as management, brokerage service, lease management and financial investment. In order to measure relationship between FDI in Chinese real estate and Chinese housing price, this document utilizes not only various data such as housing price, FDI to real estate, domestic loan of real estate, interest rate and exchange rate in 35 major cities across China but also previous researches to set an empirical analysis model and analyze effects of foreigners' direct investment in Chinese real estate on Chinese housing price.

• 한국사회정책
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• v.25 no.1
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• pp.71-96
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• 2018

Globalization, deindustrialization, and the revolutionary development of technology has led to the concerns that existing social policies might not be fit for the current and upcoming society. At the same time, the idea of universal basic income has drawn significant attentions as the alternative to the old welfare state. There are pros and cons of basic income, and scholars of both sides stand against each other with their equivalently strong logics. In this situation, some governments have planned or conducted field experiments in order to estimate the causal effects of basic income. This study explores the Finnish and Dutch basic income experiments in methodological perspective. All the World have been watching the experiments in these two countries with keen interest. The results of these experiments will surely influence on the pros and cons of basic income in numerous countries, including South Korea. It is important to precisely figure out the methodological meanings and limitations of the experiments, for the experiments in both countries deal with only some partial components of basic income and have been exposed to many threats to internal validity. Therefore, scholars for and against basic income should be careful in interpreting the findings from these experiments. This study elucidate the methodological meanings and limitations of the Finnish and Dutch basic income experiments. Furthermore, this study extracts some lessons from these experiments that would be useful if scholars would have an opportunity to design and conduct a basic income experiment in South Korea.