• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2224-2236
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• 2014

The performance of an isolated high voltage full bridge converter is improved using a voltage doubler. In a conventional high voltage full bridge converter, the diode of the transformer secondary voltage undergoes a voltage spike due to the leakage inductance of the transformer and the resonance occurring with the parasitic capacitance of the diode. In addition, in the phase shift control, conduction loss largely increases from the freewheeling mode because of the circulating current. The efficiency of the converter is thus reduced. However, in the proposed converter, the high voltage dual converter consists of a voltage doubler because the circulating current of the converter is reduced to increase efficiency. On the other hand, in the proposed converter, an input current is distributed when using parallel input / serial output and the output voltage can be doubled. However, the voltages in the 2 serial DC links might be unbalanced due to line impedance, passive and active components impedance, and sensor error. Considering these problems, DC injection is performed due to the complementary operations of half bridge inverters as well as the disadvantage of the unbalance in the DC link. Therefore, the serial output of the converter needs to control the balance of the algorithm. In this paper, the performance of the conventional converter is improved and a balance control algorithm is proposed for the proposed converter. Also, the system of the 1.5[kW] PCS is verified through an experiment examining the operation and stability.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.2
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• pp.120-127
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• 2009

This paper proposes a new Pulse Frequency Modulation(PFM)-Series Boost Capacitor(SBC) full bridge DC/DC Converter which features a high efficiency and high power density. The proposed converter controls the output voltage by varying the voltage across the series boost capacitor according to switching frequency and has no freewheeling period due to 50% fixed duty operation. As a result, its conduction loss is lower than that of the conventional phase shift full bridge converter. Moreover, ZVS of all power switches can be ensured along wide load ranges and output current ripple is very small. Therefore, it has very desirable merits such as a small output inductor, high efficiency, and improved heat generation. This paper performs a rationale and PSIM simulation of the proposed converter. Finally, experimental results from a 1.2kW(12V, 100A) prototype are presented to confirm the operation, validity and features of the proposed converter.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.71-80
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• 2005

This paper proposes a new circuit topology of the half-bridge resonant inverter and presents its digital control scheme. As the proposed half-bridge inverter can be operated in the load-freewheeling modes, pulse width modulation (PWM) control method can be used for the output power control. The proposed half-bridge inverter can keep unity output displacement factor under the load-impedance varying conditions, if a new PWM control scheme based on the resonant frequency tracking algorithm is adopted. In this paper, the operation principle, electrical characteristics and detailed digital control scheme of the proposed half-bridge resonant inverter and loss analysis comparing with a conventional half bridge inverter is described. The experimental results of the proto-type experimental setup to verify the validity of the proposed half-bridge resonant inverter are presented and discussed.

• Journal of Fashion Business
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• v.13 no.1
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• pp.152-166
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• 2009

By virtue of the development of mass media, the cinema, the composite space art taking the visual and auditory elements together, exhibits the actual life of the realities, thereby having a mutually close relationship to social, cultural and economic fields and continuing to generate the fashion code as well as reflecting the image of the times. Especially, fashion style in movies delivers their image and atmosphere and becomes the means for containing the personality, spiritual world and inner thinking of the characters in the movie and inducing its plot. Therefore, this study was intended to make clear that fashion fuses and shares with a diversity of genres such as movies and the like, becomes the cultural model that proceeds to create a new culture in relation to daily life and induces and presents the trend of contemporary fashion. For this purpose, this study attempted to analyze fashion style in the movie. Lolita is the fiction published by the Russian?American writer Vladimir Nabokov($1899{\sim}1977$) in 1954. It is the fiction that portrays the unethical love between Humbert, a middleaged man, and Lolita, a girl in her 10s. It was cinematized by the director Stanley Kubrick for the first time in 1962 and revived by the movie director Adrian Lyne in 1997. The character of Lolita has a younger look like a girl and looks immature in the movie directed by the movie director Stanley Kubrick and the movie director Adrian Lyne. But the character of Lolita has the commonality that she showed an incomplete female image of having a sexually freewheeling thinking. Thereby, this study sought to prove that the created fashion style of the character in the film not only became the clue to enable us to know the time and space background in the film but also helped the film develop effectively by performing a role of portraying the character in the movie. And it attempted to present that it becomes both the foundation for leading the fashion trend shown in contemporary fashion and the code of mass culture. Fashion style of Lolita in the movie appears to be reflected diversely in mass culture as well as fashion style in the contemporary times.

• Journal of Korean Theatre Studies Association
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• no.52
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• pp.5-59
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• 2014

This paper investigates the development and aesthetics of Korean political theatre from its quickening period 1920s to democratization era 1990s. Political theatre before 90s developed an antithesis resistant movement toward Korean modern history that had been scattered with suppressing political circumstances such as colonial era and dictatorial government, the movement has powerful activity and social influences. Just like the 20 century political theatre had been quickened under the influence of Marxism at Russia and Germany in 1920s, Korea's political theatre began in socialism theatre movement form around the same time. Proletarian theatre groups had been founded in Japan and Korea, and developed into practical movement with organized connection. However, the political theatre movement in Japanese colonial era was an empty vessel makes great sound but not much accomplishments. Most performance had been canceled or disapproved by suppression or censorship of the Japanese Empire. The political theatre in liberation era was the left drama inherited from Proletarian theatre of the colonial era. Korean Theatre alliance took lead the theatrical world unfold activities based on theatre popularization theory such as 'culture activists' taking a jump up the line and 'independent theatre' peeping into production spot as well as the important event, Independence Movement Day Memorial tournament theatre. Since 1947, US army military government in Korea strongly oppressed the left performances to stop and theatrical movement was ended due to many left theatrical people defection to North Korea. The political theatre in 1960s to 70s the Park regime, developed in dramatically different ways according to orthodox group and group out of power. The political theatre of institutional system handled judgment on sterile people and had indirect political theatre from that took history material and allegory technique because of censorship. In political theatre out of institution, it started outdoor theatre that has modernized traditional performance style and established deep relationship with labor spot and culture movement organizations. Madangguek(Outdoor theatre) is 'Attentive political theatre', satirizing and offending the political and social inconsistencies such as the dictatorial government's oppression and unbalanced distribution, alienation of general people, and foreign powers' pillage sharply as well as laughing at the Establishment with negative characters. The political theatre in 1980s is divided into two categories; political theatre of institutional system and Madangguek. Institutional Political theatre mainly performed in Korea Theatre Festival and the theatre group 'Yeonwoo-Moudae' led political theatre as private theatre company. Madangguek developed into an outdoor theatrical for indoor theatre capturing postcolonial historical view. Yeonwoo-Moudae theatre company produced representative political plays at 80s such as The chronicles of Han's, Birds fly away too, and so on by combining freewheeling play spirit of Madangguek and epic theatre. Political theatre was all the rage since the age of democratization started in 1987 and political materials has been freed from ban. However, political theatre was slowly declined as real socialism was crumbling and postmodernism is becoming the spirit of the times. After 90s, there are no more plays of ideology and propaganda that aim at politicization of theatre. As the age rapidly entered into the age of deideology, political theatre discourse also changed greatly. The concept 'the political' became influential as a new political possibility that stands up to neoliberalism system in the evasion of politics. Rather than reenact political issues, it experiments new political theatre that involves something political by deconstructing and reassigning audience's political sense with provocative forms, staging others and drawing discussion about it.