• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1818-1832
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• 1994

Transport process during solidification of an AI-CU alloy in a vertical annular mold of which inner wall is cooled is numerically simulated. A model which can take account of local density dependence on the solute concentration is established and incorperated in the analysis. Results show that thermally and solutally induced convections are developed in sequence, so that there is little interaction between them. Thermal convection effectively removes the initial superheat from the melt and vanishes as solidification proceeds from the cooling wall. On the other hand, solutal convection which is developed later over the meshy and the pure liquid regions leads to large-scale redistribution of the consituents. The degree of the initial superheating hardly affects overall solidification behavior except the early stage of the process, when the cooling rate is kept constant. Macrosegregation is reduced remarkably with increasing cooling rate, because not only the liquidus interface advances so quickly that time available for the solute transport is not enough, but also the interdendritic flow is strongly damped by rapid crystal growth within the mushy region.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.5
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• pp.856-866
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• 1987

In the present paper a statistical method using probability density function has been applied to investigate experimentally the flow patterns and fluctuations of time-averaged local void fraction in air-water two-phase mixtures which flow vertically upwards in concentric annuli. This study was carried out using three vertical concentric annuli. The annular test section consists of a lucite outer tube whose inside diameter is 38mm and a stainless steel inner rod. The rod diameter is either 12mm, 16mm or 20mm. The two-phase flow patterns observed in the experiment were bubbly, slug, annular and each transition patterns. It was first demonstrated that the variance, coefficients of skewness and kurtosis calculated from probability density function on time-averaged local void fraction can be used to identify the flow patterns in the annular passage, and the fluctuation of time-averaged local void fraction varies with the radial position in annular gap and the flow pattern.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.113-129
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• 1997

Postmordern style showed in contemporary fashion is various. Specially, street style begins from teddy boys, mods, hippy, skin head & popular fashion. They are come from mass culture. Mass culture dominated in many ways in modem society. In music, cinema & other plays we can read of youth. Street style includes youth culture about their fear and resistance and their passion. We can see kich in aetheics of street style as it was showed in mass culture. They are as follows. ${\cdot}$ Wit and sympathy expressed in primitivism. ${\cdot}$ Sensuality expressed in erotism like shows in works of Vivian Westwood & Zandra Rhodes. ${\cdot}$ Fantasy expressed cyber & psychidelic fashion.

• Journal of the Korean Society of Costume
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• v.59 no.4
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• pp.41-53
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• 2009

This study analyzed expression types of dot patterns and derived out inherent characteristics to provide fundamental resources for advancement of high value added creative designs. As a result of the study, Firstly, the circular motive was used to form silhouettes or as a symbol of a decoration. Secondly, a simple form and color dot pattern was used to create one side, or a circular shaped accessory was used to be recognized as a construction line or a decoration line. Thirdly, textile printing is mainly used but handicraft and decorative images were used to add vitality through piece technique, embroidery, collage, cut-out, patch work, etc. Fourthly, different circular motives were integrated, partitioned and duplicated for abstract geometrical images. Fifthly, variations were added by mixing different dot patterns that are arranged regularly and irregularly in different sizes and gaps creating compounded designs with handicraft touches, different angles or on top of each other. Sixthly, hybrid images were created with rearrangement of dot patterns and by adding floral shapes, stripes or other abstract and geometrical shapes. Such various and creative attempts construct new formative beauty in fashion design and I believe that it can establish the development of unique images that satisfies the taste of today's consumers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.8 s.227
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• pp.1087-1092
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• 2004

Adhesion and friction forces influence adversely on performance and durability of MEMS. It has been reported that the adhesion and friction forces can be reduced with the introduction of micro surface bumps into the contacting interfaces. In this study experiments were conducted to investigate comparatively the effect of hemispherical and torus micro bumps on the adhesion and friction forces. It is confirmed that micro bumps reduce the adhesion and friction forces, and their effect is more pronounced with the bumps of smaller outer boundary radius. Moreover, the results shows that the torus bumps exhibit more rapid decrease of the adhesion and friction forces with the decrease in the outer boundary radius of bump than the hemispherical bumps. When the magnitude of adhesion force is same, the torus bumps generate smaller friction force than the hemispherical bumps. The usage of hemispherical and torus bumps to reduce the adhesion and friction forces in MEMS is discussed.

• Journal of the Korean Society of Costume
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• v.54 no.6
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• pp.41-52
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• 2004

The objective of this study is to contemplate both the formation and the aesthetic characteristics of the ballerina look represented in modern fashion by analyzing a ballet costume. The results of this study could be summarized as the following: the ballerina look is formed by ballet costume itself with being stick to or exposing human body line, or by casual dress mixed with a ballet costume; the materials consist of both the major materials for a ballet costume such as silk, chiffon, tulle, lace, or organza, and the usual materials for casual dress: a variety of color such as transparent, pastel etc. is also used with typically used colors like white and black: decoration is basically composed of ruffle, drape, gather and the distinctive accessory like toe shoes, ribbon tape, ankle warmer is used to show a feature of a ballet costume These formative characteristics of the ballerina look presented in modern fashion implies illusory, pure, and hybridity. traits. First, illusion of the ballerina look not only implicitly expresses a womans wish to experience a ballerina's fantastic world, but also recreates woman herself into a ballerina on a stage. Second, purity of the ballerina look makes design look feminine and smooth, which is expressed with girlish taste through materials and colors. Third, hybridity of the ballerina look suggests a standard of a new trend, which is active style, by adding comfortableness and flexibleness to romantic femininity.

• Journal of the Korean Society of Costume
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• v.57 no.6 s.115
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• pp.71-86
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• 2007

Affinity between a creative and experimental fashion design and a Fashion Make-up expressed in John Galliano's Collection was analysed to examine the harmony between Beauty and Fashion. This approach may establish the link between the Fashion Make-up analysed in view of Aesthetics and aesthetic characteristics of a fashion design that a fashion designer pursues. The Fashion Make-up plays a significant role to express a relevance to a design spirit because it is a visual text that a audience faces easily in a collection leading the style. Under the proposition that collection is understood as a popular culture as the fashion is preferential and popular, the Fashion Make-up can be analysed in the aspect of aesthetics. The characteristics reflecting the popularity of popular culture, such as the comic, the erotic, the fantastic and the sentimental are used to analyse and interpret the Fashion Make-up. The fashion design and Fashion Make-up with one characteristics or combined ones showing uniqueness in the popular culture are compared and analyzed.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.795-800
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• 2000

A CCFL(Counter Current Flow Limit) test have been performed in narrow annular gaps with large diameter, because it has been confirmed that the CCFL phenomena affected the critical power in hemispherical narrow gap geometries from the SONATA(Simulation Of Naturally Arrested Thermal Attack)-IV (In-Vessel)/VISU(Visualization)-II experiments. The objectives of the CCFL experiments are to investigate the small gap sizes(1, 2mm) effect on CCFL under the large diameter condition and to confirm the findings of the VISU-II study that global dryout in hemispherical narrow gaps was induced by the CCFL. The test section was made of acrylic resin to allow visual observation on the two-phase flow behaviors inside annular gaps. It was observed from visualization that a part of water supplied was accumulated in the upper plenum and a significant increase in the differential pressure across the gap was occurred, which was the definition of the CCFL occurrence in this experimental study. From the experimental results in annular gap with large diameter it can be known that an increase in the differential pressure was not big at small air flow-rates. When the CCFL was occurred, the differential pressure across gaps was increased significantly and a water accumulated in the upper plenum. The occurrence of CCFL was correlated using the Wallis parameter.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.4
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• pp.430-439
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• 1985

Conjugate natural convection in double enclosed annuli between horizontal concentric cylinders has been studied by the numerical analysis and experimental measurements. The interface conditions between the liquid and the solid of middle shell are obtained through the correlation factor based on the ratio of solid to fluid thermal conductivities and the Prandtl number. The characteristics of conjugate heat transfer are discussed under various dimensionless parameters such as conductivity ratios, shell thickness, diameter ratios, Prandtl number, and Rayleigh number. It is found that the average equivalent conductivity K over var $_{eq}$ does not depend on the conductivity ratios and shell thickness. The K over bar $_{eq}$ however, depends on the Prandtl number and the Rayleigh number.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.514-517
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• 2016

동영상이나 게임에서 2차원적인 시야를 제공해주는 물건(컴퓨터,TV,스크린 등)이나 입체감을 주기위한 3D기술을 사용하여 보는 것에 만족하던 시대가 가고 VR(Virtual Reality)이 등장함으로 인해서 사람들이 점점 가상현실에 대한 환상을 가지고 있다. 본 연구에서는 많은 관심을 받는 VR과 동영상 Converter기술을 합쳐 공포 게임을 만들어 보며, 일반적인 공포 영상이 VR과 접목되면서 가져올 감정변화가 사람들의 관심을 끌 수 있음을 보이고자 한다.