• Journal of Hydrogen and New Energy
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• v.17 no.1
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• pp.69-74
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• 2006

Thick film $H_2$ sensors were fabricated using $SnO_2$ loaded with $Ag_2O$ and $PtO_x$. The composition that gave the highest sensitivity for $H_2$ was in the weight% ratio of $SnO_2 : PtO_x : Ag_2O$ as 93 : 1 : 6. The nano-crystalline powders of $SnO_2$ synthesized by sol-gel method were screen printed with $Ag_2O$ and $PtO_x$ on alumina substrates. The fabricated sensors were tested against gases like $H_2$, $CH_4$, $C_3H_8$, $C_2H_5OH$ and $SO_2$. The composite material was found sensitive against $H_2$ at the working temperature $130^{\circ}C$, with minor interference of other gases. The $H_2$ gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on $SnO_2-Ag_2O-PtO_x$ system exhibited the high performance, high selectivity and very short response time to $H_2$ at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of $H_2$.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.7-10
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• 2007

A thick film catalytic gas sensors which can be operated at $142^{\circ}C$ in presence of ultra violet-light emitting diode has been developed to measure hydrogen concentration in 0-5 % range. The sensing material as a combustion catalyst consists of $TiO_{2}$ (5 wt%) and Pd/Pt (20 wt%) supported on $Al_{2}O_{3}$ powder and the reference material to compensate the heat capacity of it in a bridge circuit was an catalyst free $Al_{2}O_{3}$ powder. Platinum heater and sensor materials were formed on the alumina plate by screen printing method and heat treatment. The effect of UV radiation in the presence of photo catalyst $TiO_{2}$ on the sensor sensitivity, response and recovery time has been investigated. The reduction of operating temperature from $192^{\circ}C$ to $142^{\circ}C$ for hydrogen gas sensing property in presence of UV radiation is attributed to the hydroxy radical and superoxide which was formed at the surface of $TiO_{2}$ under UV radiation.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.176-183
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• 2002

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper , Stripes of grooves of which width 48$\mu$m, depth 124$\mu$m , pitch 274$\mu$m was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6 nm Ra in grooving Si. Barrier ribs were farmed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waviness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.

• Textile Coloration and Finishing
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• v.14 no.4
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• pp.249-258
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• 2002

Natural silk is formed by two proteins : the crystalline fibroin (inside the silk thread) and amorphous sericin (as a tube outside the thread). The degumming process is used to eliminate the external sericin prior to dyeing ; generally it makes use of soaps at about pH 10. Sericin is the protein constituent that "gums"together the fibroin filaments of cocoon silk. It constitutes about 25% of the weight of the cocoon, is soluble in hot water and "gels" on cooling. The removal of sericin from raw silk, known as degumming, is a simple but important process usually employing hot dilute soap or alkaline solution and occasionally dilute acids or enzymic methods. During degumming, alkali is taken up by the sericin and the free acid from the soap is formed ; this may be deposited on the fiber, reducing the rate of degumming and protecting it from hydrolysis. Alkali is often added to maintain or restore the pH of the baths, but it is rarely used alone, since it leaves the silk rather harsh in handle. If complete sericin removal is required as for printing, sodium carbonate may be added. If the pH of the bath exceeds 11, the fibroin is attacked. Recently, According to the development of electrolysis, we can be obtained the electrolytic reduction water(above pH 11.5) and electrolytic oxidation water (below pH 3). The aim of this work was to study a degumming process using electrolytic water and a possibility of sericin recovery. The new degumming process used electrolytic water operates at $95^\circ{C}$ for 2hr. without any reagents. The wastewater of this process are formed by a solution of sericin in water. This conditions suggest the study of a possible recovery of this protein (sericin) which has an amino acid composition suitable for many used in cosmetics, textile finishing agents, animal feeding, etc. The degumming process using electrolytic water is available to reduce treatment costs and pollute and at the same time to recover sericin.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.43-54
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• 2014

In textile industry, needs for various weave drafts have been increased to produce high qualified textile goods. One of disadvantages of traditional textile industry was spending time and money on manual sampling. Nowadays, however, weave draft design and sampling using CAD programs reduce these consumption efficiently. Therefore, this study aimed to provide high qualified woven fabrics by weave draft designs influenced by geometric patterns. First, We analyzed geometric patterns, except for dot, stripe, and checks, in fashion collections from 2009 to 2014 S/S. Then, based on these analyses, design concepts were decided. Third, weave drafts influenced by geometric patterns were designed with weave CAD program, TEX PRO 10.0 by Youngwoo CNI inc. Forth, We simulated fabrics woven by new drafts using CAD programs, depending on fibers, yarns, density of woven, colors, and finishes. Unclassified geometric patterns would be expressed by small size patterns that influenced by retro moods, square patterns with various color variation, zigzag lines, and pieces of puzzles. Three design concepts were decided as greenness, neoclassic, and romantic chic. Thus, geometric patterns for printing were created as drafts for general looms, and one repeat of each draft were provided. According to the design concepts, we designed 13 fabrics with 4 geometric patterns weaving drafts. All Drafts were designed with CAD programs. Finally, same drafts were simulated as woven fabrics for both S/S and F/W seasons by changing each element, such as fiber, yarns, density, colors, and finishes.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.50-61
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• 1995

In recent years, many ceramic researchers have discoved various methods of joining ceramic to metal. However, most of these joining methods are perfomed under vacuum and pressured circumstances. So, when we join ceramic to metal,the proceedings are very complicated and require a very high cost. The purpose of this study is to develop a new joining method of an alumina ceramic to an aluminum metal in air atmosphere. The joining condition, such as copper metallizing, nickel plating, brazing, etc. was investigated through the shear strength test of the trial joint. The results obtained from the above experimenta are summarized as follows : 1) In the case of the $Al_2O_3$/$Al_2O_3$joint, the shear strength of the joint was affected by the various foctor such as kaolin content, copper metallizing thickness, firing temperature, firing time. 2) The better shear strength of the $Al_2O_3$/Al joint was obtained when Ni plating was conducted under higher current density than existing plating condition. 3) The shear strength of the $Al_2O_3$/Al joint increases with the Ni plating thickness is confined to the range of this paper. 4) The shear strength of the thermal-shocked specimen($Al_2O_3$/Al joint) was far more deteriorated than that of the as-bonded specimen.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.51-58
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• 2018

In this paper, the organic material Poly(methyl methacrylate) PMMA is used with inorganic $Al_2O_3$ to fabricate organic-inorganic multilayer barrier thin films. The organic thin films are developed using a roll-to-roll electrohydrodynamic atomization system, whereas the inorganic are grown using a roll-to-roll low-temperature atmospheric pressure atomic layer deposition system. For the first time, these two technologies are used together to develop organic-inorganic multilayer barrier thin films in atmospheric condition. The films are grown under optimized parameters and classified into three classes based on the layer structures, when the total thickness of the barrier is maintained at ~ 160 nm. All classes of barriers show good morphological, optical and chemical properties. The $Al_2O_3$ films with a low average arithmetic roughness of 1.58 nm conceal the non-uniformity and irregularities in PMMA thin films with a roughness of 5.20 nm. All classes of barriers show a notably good optical transmission of ~ 85 %. The hybrid organic-inorganic barriers show water vapor and oxygen permeation in the range of ${\sim}3.2{\times}10^{-2}g/m^2/day$ and $0.015cc/m^2/day$ at $23^{\circ}C$ and 100% relative humidity. It has been confirmed that it can be mass-produced and used as a low-cost barrier thin film in various printing electronic devices.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.545-557
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• 2020

With the increasing interest on K-fashion all over the world, it's the important time to create the items which can express the unique identity of Korea for promoting the globalization of Korean fashion. Accordingly, this study aims to suggest the modern applicability of traditional patterns by designing the bags using the Dancheong patterns(traditional multi-colored decorative painting) which can effectively express Korean images in a variety of shapes and definite visual features and then expand the scope of fashion items. To this end, this study concentrated on expressing the Dancheong patterns to fit to the modern fashion trends by re-interpreting them. The bag was designed using the laser cutting technique, without weaving or digital printing, to imbue the technical emotion and 3D effect to the patterns. In accordance with the analysis results, the features of patterns could be delicately expressed around the shaping and structuring method in terms of the design, and the scope of design for leather goods could be expanded using the laser cutting in technical aspects. For the industrial aspects, it is required to develop differentiated goods expressing the unique emotion of the Korean for globalization of Korean design.

• Journal of the Korean Graphic Arts Communication Society
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• v.27 no.1
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• pp.1-14
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• 2009

The color reproduction of digital still camera does not, in general, match those of the final output device. Because color gamut of these devices is different, it is therefore necessary to take account of a way to match. The way uses the optimized profile to output device an image. This paper proposed a way to create the input profile of digital still camera for standardization soft proofing process. The results of proposed way showed that for input profiles equivalent, good results relatively. In this paper, an experiment was done where the illumination sources used as the standard illumination 5200K and illuminated at a $45^{\circ}$ angle in the best illumination efficiently. The white balance was in mode 'custom' : aperture F11, exposure time 1/60s, ISO50, focal length 80mm. The images were exported and saved as 16bit RGB TIFF(AdobeRGB, sRGB, ProphotoRGB) images. To do the test, the RGB values of the RGB TIFF images are processed through the ICC input profile to arrive at processed $CIEL^*a^*b^*$ values. A profiling tool such as ProfileMaker 5.0 and Monacoprofile 4.8 are used to do this. The processed $CIEL^*a^*b^*$ values are compared to the reference $CIEL^*a^*b^*$ values and these two values are used to calculate a ${\Delta}E{^*}_{ab}$.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.104-113
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• 2015

Sports wear in relation to sports life is being developed in fashion industry with increasing leisure time. However, design development for swimwear including trend analysis is still required. In this research, we analyzed design trends in domestic social and cultural environment, and fashion design elements for the development for swimwear. We collected 9,549 picture images totally through 138 swimwear product catalogues in 1970s to 2014, and 8 web sites. We analyzed formative characteristics such as silhouettes, materials, colors, and textile designs. Because of the shorter cycle of social changes, and various trend, design changes of swimwear are getting diverse. Especially, color and textile design are remarkable. Also, new materials and printing technology make the design of swimming wear more comfortable and fashionable. This research would be a basic research for the design development of swimming wear.