• Journal of the Korean Society for Heat Treatment
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• v.5 no.4
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• pp.215-223
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• 1992

This study has been performed to investigate into some effects of temperature, gas mixing ratio and time on the optical microstructure, hardness and wear characteristics of medium carbon alloy steel treated by plasma nitriding. The results obtained from the experiment are summarized as follows: (1) Optical micrographs of AISI 4140 steel plasma-nitrided by the double stage technique have revealed that the nitrided layer is composed of the compound layer and the diffusion layer. The variation in temperature at the first stage gives effects, on the formation of compound layer and the growth rate is shown to be relatively fast at $460^{\circ}C$. (2) The thickness of compound layer has been found to increase with increasing nitrogen percentage in the gas mixture and the holding time. It is therefore recommended that a shorter holding time and a lower nitrogen percentage are more effective to produce a tougher compound layer and a diffusion layer only. (3) X-ray diffraction analysis for AISI 4140 steel has shown that the compound layer consist of ${\gamma}^{\prime}-Fe_4N$ and ${\alpha}-Fe$ and that tough compound layer diffustion layer only can be obtained by the double stage plasmanitriding process. (4) There is also a tendency that the total hardened layer depth increases with increasing temperature, time and nitrogen percentage in the first stage during the double stage plasma nitriding. (5) The wear resistance of plasma nitrided specimens has been found thobe considerably increased compared to the untreated specimens and the amount of increment has appeared to increase further with increasing nitriding temperature, holding time and notrogen percentage of gas mixture in the first stage treatment.

• Journal of Powder Materials
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• v.13 no.6 s.59
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• pp.421-426
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• 2006

The microstructural and mechanical properties of Al-Si alloyed powder, prepared by gas atomization fallowed by hot extrusion, were studied by optical and scanning electron microscopies, hardness and wear testing. The gas atomized Al-Si alloy powder exhibited uniformly dispersed Si particles with particle size ranging from 5 to $8{\mu}m$. The hot extruded Al-Si alloy shows the average Si particle size of less than $1{\mu}m$. After heat-treatment, the average particle size was increased from 2 to $5{\mu}m$. Also, mechanical properties of extruded Al-Si alloy powder were analyzed before and after heat-treatment. As expected from the microstructural analysis, the heat-treated samples resulted in a decrease in the hardness and wear resistance due to Si particle growth. The friction coefficient of heat-treated Al-Si alloyed powder showed higher value tough all sliding speed. This behavior would be due to abrasive wear mechanism. As sliding speed increases, friction coefficient and depth and width of wear track increase. No significant changes occurred in the wear track shape with increased sliding speed.

• Journal of Agricultural Extension & Community Development
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• v.16 no.2
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• pp.285-304
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• 2009

The objectives of this study were finding out some methods about development of oversea agriculture in Korea. It is a tough task that faces us now. China is a big agricultural country, most agricultural investment country and the nearest located in Korea. So this study researches on the quality of farmers and characters of rural human resources in China. In China, agriculture industry is the basic industry among national economy developments. The majority of populations in China are living in rural region. Agriculture, villages and farmers are main issues in China. From this point, An analysis of Chinese farmers' characters and qualities; general conditions of farmers' knowledge of science and technology, their education level, quality of minds and sprit, and rural public health service situation in China. The result of this study is following; First, Chinese farmers' factors that low education level, big cultural differences between cities and country sides affect the development of China's agriculture as obstruction factors. Second, Practice conditions of farmers' science knowledge and technology are low level, output of higher rural human resources, low quality of minds and sprit and problems of agricultural extension service. It is negative influenced of agriculture and farmers economic development in China. Third, unsociable culture of the peasantry influences Chinese farming in the negative ways. Also, conventional notions of family are getting weaker, it makes connection of the kinship weaken. But, Chinese think that this kind of kinship is the most important thing in their life. Fourth, in the case of situations that the farmer's sanitation and health, low level of the medical service is getting worse than before relatively. And there are a lot of discordances between a planned childbirth policy and personal recognitions. Also, lacking of nourishment makes labor productivity falling tendencies. The medical industry falls short of the standard as compared to the number of farming people. Fifth, in the peasantry's consciousness of the legal system, this causes difficulties to farmers in the market. Shortage of the legal knowledge exerts a bad influence upon rural economy.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.389-395
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• 2016

Korean cartoons, seeking an exit from economic distress, naturally entered the era of webtoons as the Internet arose in early 2,000s. Webtoons, a new concept of cartoon, are drawn mostly by oneself, whereas cartoons before were drawn with the help of many apprentices. This research demonstrates that webtoon artists are required to use many programs and fully understand the Internet environment in order to draw webtoons. This tough conditions pose many problems for an artist who should draw well and quickly under the circumstances. We are now at a stage where a simple webtoon program is needed and will go over alternatives. I have researched characteristics, advantages and disadvantages of webtoon's core programs such as Photoshop, Comicstudio, Cytool, and Clipstudio, and what would be the optimal functions for webtoons. I offer new programs that are optimized for story cartoons that can be utilized with webtoons.

• Journal of Mushroom
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• v.3 no.4
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• pp.129-132
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• 2005

A new functional mushroom cultivated variety "Jangsaeng" of Fomitella fraxinea was developed by crossing monokaryons derived from collected strains for contribution to mushroom farmers. The major characteristics of this mushroom were compared to Yeongji 2ho of Ganoderma lucidum because of their morphological similarities. The optimal temperature of mycelial growth and fruitbody sprouting and growth were 30 and 25~30, respectively. The surface color of fruitbody pilus was reddish brown and the fruitbody was flat kidney-shaped like Ganoderma lucidum except that the stipe was absent. Its texture was so tough and rigid that the yield per 1,000 ml bottle might be as high as 136 g. The hot water extract of this medicinal mushroom is fit to drink just like Ganoderma lucidum but its taste is not bitter.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.125-136
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• 2019

The radish skin and radish greens are an edible part of the radish. But they are removed before eating the radish and used as a byproduct or an animal feed material because of their tough and rough texture. Melanin is a pigment that gives colour to our skin. But increased production of melanin can turn into benign or malignant tumours. These days due to global warming, the amount of Ultra violet (UVB) rays has been extensively increased with sunlight. Due to this, a phenomenon called exogenous photo aging is widely observed for all skin colour and types. As a result of this phenomenon, a set of enzymes called matrix metalloproteinases (MMP's) that serves as degradation enzymes for extracellular matrix proteins mainly collagen is increased, causing depletion in collagen and resulting in early wrinkles formation. Therefore in our study we used the murine melanoma cell line B16/F10 to study the melanogenesis inhibition by Heated radish extract (HRE) in vitro and we used HRM-2 hair less mice exposed to artificial UVB for checking the efficacy of Heated radish extract in vivo. Furthermore, we prepared a 3% Heated radish extract (HRE) cream and checked its effects on human skin. Our results have clearly demonstrated that Heated radish extract (HRE) have potently suppressed the tyrosinase activity and melanin production in B16/F10 cells. It had also reduced the expression of components involved in melanin production pathway both transcriptionally and transitionally. In in vivo studies, HRE had potently suppressed the expression of MMP's and reduced the wrinkle formation and inhibited collagen degradation. Moreover, on human skin, ginseng cream increased the resilience, skin moisture and enhanced the skin tone. Therefore in light of these findings, we conclude that HRE is an excellent skin whitening and antiaging product.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.284-288
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• 2003

This study was investigated the nondestructive characteristics of the damage caused by low-velocity impact on symmetric cross-ply laminates. These laminates were $[0^{\circ}/90^{\circ}]{_{16s,}}\;{_{24s,}}\;{_{32s,}}\;{_{48s}}$, that is, the thickness was 2, 3, 4 and 6 mm. The impact machine, model 8250 Dynatup Instron, was used a drop-weight type with gravity. The impact velocities used in experiment were 0.75, 0.90, 1.05, 1.20 and 1.35 m/sec. The load and deformation were increased as impact velocity increase. Even if the load increased with laminates thickness in same impact velocity, the deformation decreased. The extensional velocity was a quick as laminate thickness increase in same impact velocity and as impact velocity increase in same laminate thickness. In ultrasonic scans, damaged area was represented an dimmed zone. This is due to the fact that the wave, after having been partially reflected by the defects, has not enough energy to tough the oposite side or to come back from it. The damaged laminate areas were different according to the laminate thickness and the impact velocity. The extensional velocities became lower in if direction and higher in $0^{\circ}$ direction when the size of the defects increases. But, it was difficult to draw any conclusion for the extensional velocities in $45^{\circ}$ direction.

• Journal of agriculture & life science
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• v.43 no.4
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• pp.33-36
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• 2009

Globose to clavate base-ball sized, pear shaped, fruiting bodies were found under the Himalayan cedar, Cedrus deodora at less fertile and poor sandy poor soil in the campus of Gyeongsang National University in Jinju, Korea. The fruiting body was at first, round to club-shaped, usually with a narrow, rooting base with yellowish rhizomorphs attached to it and lack a volva and a sterile base. The peridium of fruiting body was tough and crusty. The peridioles were white pea-like capsules in a blackish matrix. The color change to darker tints of brown at the top of the exterior peridium reflected the gradual ripening of the interior gleba and peridioles, which proceeded from the top downward to become a mass of spore dust, appearing as cinnamon brown at the apex of the vertical section. At around this stage, the peridium cracked open linearly, exposing the gleba with powdery spores mass released from overmatured peridioles. Spores were more or less round, warty or spiny, 10 to $12{\mu}m$; globose, cinnamon brown in powdery mass, with spines up to $2{\mu}m$ long. The thin peridium ruptured further in response to the disintegration of the peridioles, releasing the powdery spores, which proceeded until whole fruiting body disappeared leaving the dry spore dust coats in the vicinity. The absence of a capillitium is a distinctive characteristic that distinguishes the specimen from other puff-ball fungi and from most of earthballs. Based on the above characteristics, the specimen was identified as Poslithus tinctorius.

• English & American cultural studies
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• v.16 no.2
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• pp.47-70
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• 2016

Under the inhumane oppression of imperialism, the Third World's political violence has been often represented as an immediate and explosive one with an instant, concentrated visibility. Yet the ecological and psychological exploitation of the Third-World countries by empires, as Rob Nixon insists, shows the relative invisibility of slow violence. This paper is to reveal this slow violence of the marginalized areas symbolized as the lowland. Although Arne Naess' deep ecology promotes the inherent worth of living beings regardless of their instrumental utility to human needs. this paper deals with three postcolonial ecological textbooks which criticize the white-centered deep ecology: Amitav Ghosh's The Glass Palace, Jhumpa Lahiri's The Lowland, and Barbara Kingsolver's The Poisonwood Bible. Through postcolonial critical study, this paper finds out that all these three works have some themes in common. First, these postcolonial works assume a shape of family saga which is parallel to the slow violence of ecological and psychological plundering of empires in the postcolonial countries. Second, like the mangroves which have a tenacious hold on life, these postcolonial people rather overcome the heterogenic challenge with the sturdy and tough mind than defeated. Third, the native people's ethics of earth functions as the stronghold for their respectable lifestyle in their indigenous historicity. Finally, as a big fat brother, the Americanized globalization or neoliberalism is warned as the neocolonialism which is often shown as the disguised pattern of greenwashing. Namely, the people's self-enhancement is always prior to the imperialistic development or neoliberalism in the postcolonial ecological texts which sharply contrast the native's life consciousness and the empire's development theory.

• The Southeast Asian review
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• v.20 no.2
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• pp.1-29
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• 2010

In 1835, quickly after the Cambodian king Ang Chan died, Vietnamese emperor Minh Mang started to proceed his ambition to grab the territory of Cambodia. As the first step, he stationed big forces led by Truong Minh Giang in Phnom Phen, and appointed the Ang Chan's second daughter, Mei, as the successor of her father but with the humble title of Chan Lap Quan Chu, or the Prefecture sovereign of Cambodia. This article discusses the ways how the Vietnamese leaders manipulated the status of the Cambodian queen with each step of protection, assimilation, and finally a rupture. The author seeks for Vietnamese own theory of annexation in the process. In doing so, the author claims that Vietnamese tough policy of annexation was closely interwoven with the unequal relationship between the Vietnamese emperors and the Cambodian queen, i. e. men and woman. The first chapter discusses how and why the second daughter was chosen, and what in reality the status of the queen was under the protection of Vietnamese general Truong Minh Giang. Second chapter shows how much Mei was bullied by the Vietnamese. She was kidnapped to Vietnam, and was even regarded by the Cambodian people that she became the 'lover' or the 'concubine' of the general Truong Minh Giang. Third chapter deals with Vietnam's retreat forced by the Cambodian resistance together with the Thai intervention, and discusses how much Vietnam tried to maintain its authority over Cambodia through the queen Mei. Cambodia, in the 19th century, was a experimental place for the 'mission of civilization' from the side of Vietnam. Mei was a main character in this period from the beginning to the end. The conclusion of this article stresses that the desire of Vietnam ('civilized') to assimilate Cambodia ('barbarious') was strengthened by the psychology of the male master (Vietnam) to domesticate the female subject (Cambodia). The relationship between Vietnam and Cambodia was not only political but also gender oriented. In this epic, the existence of the queen Mei should be regarded as an important key to understanding of the Vietnamese theory for the annexation of Cambodia.