• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.6
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• pp.527-534
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• 2015

This study offers a novel method for improving the physical contact between the anode and fuel in a direct carbon fuel cell (DCFC): a direct generation of carbon in a porous Ni anode through the thermal decomposition of gaseous hydrocarbons. Three kinds of alkane hydrocarbons with different carbon numbers (CH4, C2H6, and C3H8) are tested. From electron microscope observations of the carbon particles generated from each hydrocarbon, we confirm that more carbon spheres (CS), carbon nanotubes (CNT), and carbon nanofibers (CNF) were identified with increasing carbon number. Raman scattering results revealed that the carbon samples became less crystalline and more flexible with increasing carbon number. DCFC performance was measured at $700^{\circ}C$ with the anode fueled by the same mass of each carbon sample. One-dimensional carbon fuels of CNT and CNF more actively produced and had power densities 148 and 210 times higher than that of the CS, respectively. This difference is partly attributed to the findings that the less-crystalline CNT and CNF have much lower charge transfer resistances than the CS.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.183-190
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• 2015

An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of $35^{\circ}$ was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.64-72
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• 2017

The longitudinal dynamic instability which can occur in the fueling process of a space launch vehicle is called pogo. It is caused by coupling between the fuselage and propulsion system and they would be formed as a closed-loop system. so that the amplitude of the response may increase or decrease. In this paper, a mathematical model which is applicable to the systematic pogo analysis of a general launch vehicle is developed for an example of space shuttle. The formulations are composed of the linearized second-order differential equation for the propulsion system, and of the pressure, weight displacement, and generalized displacement. Those are important parameters for pogo analysis, are derived through eigenvalue analysis. By the formulation suggested in this paper, it is expected that mathematical modeling method of the pogo system can be obtained and systematic pogo stability analysis for any launch vehicle will be enabled.

• Cross-Cultural Studies
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• v.47
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• pp.1-26
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• 2017

This paper focuses on three novels that reflect absence of family. Conflicts caused by absence of parents or lack of function and role of parents were principle drivers fueling growth novels. In Chinese growth novels, children in a long-standing tradition of emulsion and political pressure were unable to express their conflict with parents. Out of the collective interest and only until the late 1980s, which can be found of the individuals were able to fully appreciate the growth of children. Since the late 1990s, the creative individual cases to the growth is an important point of Chinese growth. Due to a close relationship of the literature and politics further noteworthy that the growth of state for personal growth for China's growth. Reform and opening up the end of the Cultural Revolution, the emergence of new generation of cultural sensitivity with a relatively free personal attention to the growth of the chance that can be. In this paper, created since the 1990s, the growth of the stories of yuhua (余華)'s "Cry in the Rain"("在細雨中呼喊"), sutong(蘇童)'s "The Northern Part of the City"("城北地帶"), wanggang(王剛)'s "English"("英格力士"), going to go through by focusing on how to respond in the lack of family. "Cry in the Rain" shows that a consciousness orphan child abandoned main actors 'consciousness from his birth parents and adoptive parents. "The Northern Part of the City" chronicles different growth stories of children who experienced a void because of their absent families and found comfort in peer groups. "English" is distinguished from the mainstream narrative of Chinese growth in terms of creating a role model. Individual growth through the role model in that it will eventually establish their own identities and further growth. Because of that, this novel is considered best practices of Chinese growth novels. This kind of narrative, which returns to the memory of the growth of growth, has a richer connotation amid various attempts by writers out of the past era of obsession and fatigue.

• Journal of Popular Narrative
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• v.25 no.4
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• pp.321-359
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• 2019

In the 1970s, the full-scale development of the area now known as Gangnam began, ushering in the era of real estate investment on apartments which transformed housing styles in Korea. Apartments were pitched as the most ideal type of housing, creating a competitive market of high demand and skyrocketing prices. The apartments were also viewed as a means of quick asset investment among middle-class Koreans. Within this apartment frenzy stood the female real estate speculator, the bokbuin. This study seeks to locate the bokbuin in the real estate development market after the late 1970s. The apartment speculation boom cannot be attributed to the bokbuin alone, yet she became the target of public anger and criticism, singled-out as being responsible for fueling illegal and unethical investments. The apartment boom of the 1970s was in fact generated in large part by the government, developers, construction companies and realtors. While their pursuit of profit was deemed as legitimate, the bokbuin's conduct was mostly tainted by presumed illegitimate and greedy motivations. This study problematizes this gendering of real estate investment and treat the bokbuin as a byproduct of the family-centered culture in East Asia. Analyzing Im Kwon Taek's film "Mrs. Speculator", Park Ki Won's conte, "Bokbuin", Park Wan Seo's short story, "Children of Paradise", "The People of Seoul", this study shows that bokbuin's pursuit was not hers alone; it was the collective pursuit with her husband for the enhancement of family finances. This stud y argue that the bokbuin embodied the thickly misogynistic climate of the 1970s that projected the chaotic rise of greed onto the woman.