• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.30-35
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• 2020

A microlens has been fabricated by various methods such as a thermal reflow, hot embossing, diamond milling, etc. However, these methods require a relatively complex process to control the microlens shape. In this work, we report on a simple and cost-effective method to fabricate a cylindrical microlens (CML), which can diffuse light widely. We have employed a slot-die head with the dual plate (a meniscus guide with a protruded μ-tip and a shim with a slit channel) for coating of a narrow stripe using poly(methyl methacrylate) (PMMA). We have shown that the higher the coating gap, the lower the maximum coating speed, which causes an increase in the stripe width and thickness. The coated PMMA stripe has the concave shape. To make it in the shape of a convex microlens, we have applied the thermal reflow method. When the stripe thickness is small, however, its effect is negligible. To increase the stripe thickness, we have increased the number of repeated coating. With this scheme, we have fabricated the CML with the width of 223 ㎛ and the thickness of 7.3 ㎛. Finally, we have demonstrated experimentally that the CML can diffuse light widely, a feature demanded for light extraction efficiency of organic light-emitting diodes (OLEDs) and suppression of moiré patterns in displays.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.367-373
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• 2014

Surface texturing is a machining process on the surface to give engineering functions. The representative process of the surface texturing is lotus effect to give hydrophobic property by the lithography and chemical etching, which is the bio mimic from the nature. Surface texturing can be manufactured by a lot of processes, in particular using mechanical method such as a precise diamond turning, grinding, rolling, embossing, vibrorolling, and abrasive jet machining (AJM). Among them, the grinding process is notable in terms of the wide range of texturing area and fast processing time. The patterning by grinding is done by the grooved grinding wheel on the work piece. In this case, the pattern shape is determined by the grinding conditions as well as the wheel dressing conditions. In this paper, experimental study on the pattern shapes were done and provide the feasibility in use for the large area patterning.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.100-103
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• 2007

A microlens array has been required to improve light conversion efficiency in image sensors. A microlens array can be usually fabricated by photoresist reflow, hot-embossing, micro injection molding, and UV-imprinting. Among these processes, a UV-imprinting, which is operated at room temperature with relatively low applied pressure, can be a desirable process to integrate microlens array on image sensors, because this process provides the components with low thermal expansion, enhanced stability, and low birefringence, furthermore, it is more suitable for mass production of high quality microlens array. In this study, to analyze the optical properties of the wafer scale microlens array integrated image sensor, another wafer scale simulated image sensor chip array was designed and fabricated. An aspherical square microlens was designed and integrated on a simulated image sensor chip array using a UV-imprinting process. Finally, the optical performances were measured and analyzed.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.515-532
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• 2014

Objective: The purpose of this study is to define consumers' affection on the interior design of commercial cars in terms of its design factors: color, embossing and gloss as independent factors. Background: Existing affective studies related to interior of vehicle focus on just sedans. However, there is no affective study about the interior of commercial cars. In addition, it is hard to change levels to which manufactures want. Method: Representative design factors were drawn using ANOVA and SNK analysis and definitive affective vocabularies were drawn using factor analysis. Furthermore, the results of 3D experiment were analyzed using ANOVA and LSD analysis. 3D images for the experiment were made using 3D max program. The experiment revealed that consumers discerned the differences in levels of each design factor and affective vocabulary. Results: The ANOVA revealed that beige color "A" type and non-gloss were the most preferred design in terms of the affective vocabularies and total preference. Conclusion: The result of the experiment may help manufactures to design the interior of commercial cars in the near future. Furthermore, the ANOVA result of affective vocabularies evaluation is expected to suggest a meaningful guideline. Application: The study results may be utilized as a guideline for interior design of commercial cars.

• The Research Journal of the Costume Culture
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• v.15 no.4
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• pp.702-712
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• 2007

The purpose of this study was to understand the current trend with regard to the material of jeans and the making method of jeans pattern and the characteristics of washing processing through the overall production status of jeans in casual brands and to offer the basic data for producing the high efficient jeans. The results were as follows. According to the survey of production status of jeans in casual brands, the fabric mixture was highest in the order of non-stretch denim 100% cotton, stretch denim cotton/spandex mix and denim with $1{\sim}2%$ weft direction spandex mix. The most frequently used processing method for denim was in the order of normal finishing, mercerization finishing, soft finishing and pigment finishing. The most frequently used method of washing finishing for jeans was in the order of forming by embossing washing, bio stone washing, normal washing, bio washing, and bio stone bleach washing. The average shrinkage was higher on waist circumference and pants length of warp direction rather than hips circumference, thigh circumference, hem circumference of weft direction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.9
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• pp.676-682
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• 2008

Numerical analysis was carried out to examine the heat transfer and pressure drop characteristics of plate heat exchangers for absorption application using Computational Fluid Dynamics(CFD) technique. A commercial CFD software package, FLUENT was used to predict the characteristics of heat transfer, pressure drop and flow distribution within plate heat exchangers. In this paper, a welded plate heat exchanger with the plate of chevron embossing type was numerically analyzed by controlling mass flow rate, solution concentration, and inlet temperatures. The working fluid is $H_2O$/LiBr solution with the LiBr concentration of 50-60% in mass. The numerical simulation shows reasonably good agreement with the experimental results. Also, the numerical results show that plate of the chevron shape gives better results than plate of the elliptical shape from the view points of heat transfer and pressure drop. These results provide a guideline to apply the welded PHE for the solution heat exchanger of absorption systems.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.175-197
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• 1998

High quality-oriented consumers, new rationalism and concept-oriented consumption followed by high sensitivity fashion market are embossing the importance of fashion M.D. This study has a purpose to make practical and general approach to consumers' taste, trend receptivity, the propensity to consume, and how they are practically connected with market strategy. As a results of this study, First niche market, targeting a new consumer group, is embossed as consumers have new fashion lifestyle. Second, we need a strategy to fractionize fashion by developing concepts suitable for consumers' each scene, not by following radical trends for mature consumers. Third, to satisfy consumers' propensity to originally, we need to establish the identity of Korean original goods which can compete with world-famous brands.

• The Research Journal of the Costume Culture
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• v.19 no.1
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• pp.71-82
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• 2011

This paper examined the kinds and characteristics of leather and also analyzed the expression techniques and characteristics of leather in contemporary fashion. The objective of this study lies in re-interpreting the current location of leather in contemporary fashion design, enlarging unlimited potential expression fields of leather, and at the same time, helping create new viewpoints and expression types of leather. For this purpose, this paper examined the kinds and characteristics of leather through the existing literatures, and it also carried out positive analysis of the expression techniques and characteristics of leather clothes through local and foreign fashion magazines and collection papers, such as Gap, Vogue, and Mode & Mode, focusing on the works presented in the fashion collections after 2000. Leather in contemporary fashion is expressed in different colors through dyeing. Through various expression techniques such as wrinkles, ruffle, stitch, embossing, quilting, patchwork, holing, nailing, cutting, laser cutting, fringe, weaving, printing, and collage, leather breaks the fixed ideas of itself and further, it makes the images of fashion design affluent. Leather clothes, which are made through various expression techniques, have some characteristics. First, leather clothes emphasize women's voluptuous beauty. Second, leather clothes create a decorative effect through mixture of materials and various expression techniques. Third, through the feel of materials and the emphasis of shapes, primitive beauty is expressed.

• Journal of the Korean institute of surface engineering
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• v.49 no.2
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• pp.178-185
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• 2016

In this study, we have fabricated light guide plates (LGPs) in thin film form for edge type back light unit (BLU) by using UV imprint lithography. In the LGPs, the pattern of functional resins on PC and PMMA substrates were successfully transferred from original master mold through PVC stamp. Optimized pattern arrays with slowly-sloped density were designed to obtain high brightness and uniformity. We could obtain a relatively improved brightness of $950cd/m^2$ and a uniformity of 87.3% by using the NP-S20 functional resins at an input power of 1.3 W because NP-S20 resin could show high formability after UV hardening process. The LGP prepared on polymethylmethacrylate (PMMA) substrate exhibited higher brightness than that on polycarbonate (PC) substrate because PMMA has lower refractive index resulting in more refraction toward the vertical direction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.88-91
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• 2005

본 논문에서는 비정질 As-Ge-Se-S 박막의 에칭 레이트를 측정하였으며 As-Ge-Se-S 박막에 회절격자를 형성 시킨 후 선택적 에칭을 통한 엠보싱 홀로그램을 제작하였다. NaOH 수용액으로 0.26N, 0.33N, 0.40N 농도로 변화시키며 수행하였으며 에칭 시간에 따른 에칭되는 두께의 변화를 측정하였다. 에칭 레이트는 NaOH 용액의 농도가 0.26N, 0.33N, 0.40N 일 때 각각 $2.5{\AA}/s$, $3.3{\AA}/s$, $3.9{\AA}/s$ 였다. 또한 2차원 엠보싱 회절격자를 형성 시킨후 0.26N NaOH용액으로 60초간 선택적 에칭을 수행하여 AFM(Atomic Force Microscopy) 으로 측정한 결과 선명한 엠보싱 형태의 회절격자를 확인 할 수 있었다.