• Journal of Institute of Control, Robotics and Systems
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• v.3 no.6
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• pp.619-625
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• 1997

In this paper, we show that the rotor position of the bifilar-wound hybrid stepping motors for the closed-loop drives is detected by the phase current measurement. We propose an instantaneous phase current equation, which is the function of electrical angle, by modeling the stepping motor including motor driving circuits. We also analyze the relationship between phase current and rotor position from the computer simulation results. We show that the information about the rotor position is obtained from the phase current amplitude and its derivatives at the instance of ${\pi}/2$ electrical angle of excitation voltage.

• (The)Study of the Eastern Classic
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• no.59
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• pp.57-92
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• 2015

This study looked into the process by which Haseo(河西) Kim In-hoo(金麟厚:1510~1560), a neo-confucian scholar of mid Joseon Dynasty, was recognized and adored as an inheritor of traditional academic genealogy of neo-confucianism of Joseon Dynasty. I intended to examine the process of personal embodiment affected or excluded in certain manners by various materials covering the lifetime of bygone persons based on the process of such embodiment. The part related to childhood of Haseo was arranged newly to highlight solid relationship between Kim In-hoo and King Injong(仁宗). That was because Kim In-hoo raised the issue of loyalty and fidelity, one of the most important and most contentious issues at that time, in connection with reinstatement of GimyoSarim(己卯士林, progressive political faction with young officials), and King Injong was the king who reinstated Gimyo Sarim. That played a decisive role in establishing the image of Haseo, a classical scholar with unwavering integrity and loyalty. During the Late Joseon Dynasty, canonization of Haseo was made under the leadership of King Jeongjo(正祖) and Seoin(西人) in royal court. In the 17th century, Seoin scholars revised the materials related to lifetime of Kim In-hoo in various way and proofread and published the collection of literary works by Kim In-hoo. That aimed to establish scholastic system associated with Seoin and legitimacy of study as pursued by Seoin. This made progress with adoration towards scholars affiliated with Seoin, including Yulgok(栗谷) Lee Yi(李珥). Finally, King Jeongjo showed strong intention to take the lead as sovereign in the process while Haseo was canonized into national academy in the 18th century. That came from the desire to solidify his status as a teacher who took pride in taking responsibility for the dynasty's authentic study, as well as the king heading the dynasty politically.

• Korean Journal of Culture and Social Issue
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• v.16 no.3
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• pp.331-354
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• 2010

Previous psychological studies in gambling have mainly focused on the characteristics of gamblers. the purpose of the present study was to categorize gambles in Korea into subtypes based on winning probability and money and to examine variations of gambling behaviors and problems across the gamble subtypes. A survey on 1,304 gamble participants were conducted, of their gambling behaviors, personal and social problems, and CPGI. First, factor analyses on perceived winning probability and money revealed 6 subtypes of gambles: amusement type, lottery type, internet type, slot-machine type, racing type and casino type. Secondly, comparisons among gamble subtypes revealed the differences in gambling behaviors, gambling-related cognitions, emotional experiences during gambling, and personal/social problems related to gambling. The gambling behaviors in slot-machine type, racing type, and casino type were more negative than those in amusement type, and lottery type. Gamblers in internet type were found to have potential for latent problems of gambling. In discussion, the academic and practical values and implications of typology of gambles were further discussed.

• Korean journal of communication and information
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• v.31
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• pp.113-165
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• 2005

The research focused on the return of class analysis of the media soctor. It is told that class is a determining factor of media industry. This article is divided in to four sections that represent class analysis of media. In this study, I claimed that class analysis is necessary of understanding the nature of media industrial capital and its nature. With their domination of the media, big corporations seek to control political power and information. This article has demonstrated that the media power of corporations should be curved.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.503-512
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• 2020

The products using blowers include hand dryers, automatic car washers, dryers, and vacuum cleaners. The features of these products require a structure and control algorithm so that a strong wind is blown out at the moment. Electric motors according to the existing excitation method include a direct winding type, a decentralized type, a lottery type, and a permanent magnet type. Conventional electric motors have a disadvantage when the starting current is large during high-speed rotation and the number of rotations is irregular. In order to improve this, research on high-speed BLDC motor control has designed 800W-class high-speed BLDC motor control and circuit through driving circuit design, sensorless control algorithm, simulation, experiment, etc., and more than 95% high efficiency evaluation method of driving performance of controller, prototype experiments and verification were studied.

• Convergence Security Journal
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• v.20 no.2
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• pp.69-76
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• 2020

Blockchain 2.0 supports programmable smart contract for the various distributed application. However, the environment of running smart contract is limited in the blockchain, so the smart contract only get the deterministic information, such as block height, block hash, and so on. Therefore, some applications, which requires random information, such as lottery or batting, should use oracle service that supply the information outside of blockchain. This paper develops a random number generator oracle service. The random number generator oracle service use irregular big data as entropy source. This paper tests the randomness of bits sequence generated from oracle service using NIST SP800-22. This paper also describes the advantages of irregular big data in our model in perspective of cost comparing hardware entropy source.

• Journal of Korea Game Society
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• v.18 no.1
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• pp.95-104
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• 2018

This study analyzes the system of Loot Box in Overwatch, FPS genre game produced by an American company Blizzard. Currently, one of the most controversial issues in the recent industry is "Probability-Type Item" that game users purchase high-end game items as a form of lottery. As this study examines a foreign case of Loot Box that is similar to Probability-Type Item, it would show how it is constructed and does legal approaches. Throughout this, it not only analyzes pros and cons of the Loot Box system, but also provides thought-provoking messages for the issue of the Probability-Type Item.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.113-129
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• 2023

Purpose - The purpose of this study is to examine whether trading volume amplifies the extent to which lottery-type stocks are overpriced, and whether economic sentiment index explains time-variation in the magnitude of the volume amplification effect. Design/methodology/approach - We examine monthly returns on 5x5 monthly bivariate portfolios formed by lottery characteristics (measured by maximum daily return) and trading volume. In addition, we perform time-series regression tests to examine how the volume amplification effect changes in high and low economic sentiment periods, after controlling for Fama-French three factors. Findings - Our bivariate portfolio analysis shows that the overpricing of lottery-type stocks are mostly pronounced among high trading volume stocks. In contrast, for low trading volume stocks, overpricing of lottery-type stocks appears to vanish. Furthermore, the amplification effect of trading volume on overpricing of lottery-type stock is concentrated in high economic sentiment periods. Research implications or Originality - This study is the first attempt to examine whether trading volume drives lottery-type stocks' overpricing in the Korean stock market. Furthermore, our analysis unveils the time-varying nature of volume amplification effect. The results suggest that trading volume might play a important hidden role in asset pricing, opening a new line of researches in the future.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.559-575
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• 2003

The purpose of this study is to systematically explain and discuss the return migration of Koreans in Central Asia to the Russian Far East. The Koreans' return migration is explained by the combination of push and pull factors inherent in the host and home countries. The structural or institutional push factors in Central Asia include the linguistic policy of a country, civil war, ethnic conflicts, while the micro ones are the Koreans' high concern of their children's education and the improvement of a socio-economic status. The macro pull factors operated in the Russian Far East are the permission to use the housing facilities and land previously controlled by military authorities and the laws of recovering the koreans' basic right and honor, while the micro ones are the networks of relatives and friends living in Central Asia and the Russian Far East. The two aspects related to the Koreans' return migration are also discussed. Firstly, the return migration of Koreans in Central Asia is interpreted as a migration of ethnic affinity. Secondly, the establishment of an autonomous district of Koreans in the Russian Far East is discussed.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.291-302
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• 2020

Korean popular music industry, which is lead by "Idol group", has forsaken their fandom all over the world. Therefore, idol groups has become not only an artist but also the most influential people in the Korean economy. A global idol group with a strong fandom can earn more than a trillion-dollar by attracting their global fan's interest in Korea. In other words, it is considerably important to carry the idol to a successful conclusion. This study tries to expect whether the idols can be survived or not at a certain point after their debut by ANN, Decision Tree, Random Forest. We decide that certain point as the three-year and eight-year after their debut, because it is their break-even point year and the year after their average renewal of the contract. In addition, this study also explains which feature is the most important to their survival by feature importance and Logistic regression. In conclusion, features like the number of idol competitors, the number of debut members and the number of the genre are significant. These results shed light on the efficient management of K-Pop idol to improve industrial competitiveness.