• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.245-253
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• 2010

The reliability problems of flip chip packages subjected to temperature change during the packaging process mainly occur due to mismatches in the coefficients of thermal expansion as well as features with time-dependent material properties. Resin molding compounds like glass fiber reinforced epoxy composites used as the dielectric layer in printed circuit boards (PCB) strongly exhibit viscoelastic behavior, which causes their Young's moduli to not only be temperature-dependent but also time-dependent. In this study, the stress relaxation and creep tests were used to characterize the viscoelastic properties of the glass fiber reinforced epoxy composite. Using the viscoelastic properties, finite element analysis (FEA) was employed to simulate thermal loading in the pre-baking process and predict thermal warpage. Furthermore, the effect of viscoelastic features for the major polymeric material on the dielectric layer in the PCB (the glass fiber reinforced epoxy composite) was investigated using FEA.

• Clean Technology
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• v.28 no.3
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• pp.203-209
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• 2022

An environmental evaluation was conducted by employing LCA methodology for a mechanical seal manufacturing process that uses recycled silicon recovered from end-of-cycle PV modules. The recycled silicon was purified and reacted with carbon to synthesize β-SiC particles. Then the particles underwent compression molding, calcination and heat treatment to produce a product. Field data were collected and the potential environmental impacts of each stage were calculated using the LCI DB of the Ministry of Environment. The assessment was based on 6 categories, which were abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion and photochemical oxidant creation. The environmental impacts by category were 45 kg CO₂ for global warming and 2.23 kg C₂H₄ for photochemical oxide creation, and the overall environmental impact by photochemical oxide creation, resource depletion and global warming had a high contribution of 98.7% based on weighted analysis. The wet process of fine grinding and mixing the raw silicon and carbon, and SiC granulation were major factors that caused the environmental impacts. These impacts need to be reduced by converting to a dry process and using a system to recover and reuse the solvent emitted to the atmosphere. It was analyzed that the environmental impacts of resource depletion and global warming decreased by 53.9% and 60.7%, respectively, by recycling silicon from end-of-cycle PV modules. Weighted analysis showed that the overall environmental impact decreased by 27%, and the LCA analysis confirmed that recycling waste modules could be a major means of resource saving and realizing carbon neutrality.

• Fashion & Textile Research Journal
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• v.9 no.6
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• pp.613-625
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• 2007

Globalizing the Japanese fashion successfully, Hanae Mori's work awoke the western fashion world's nostalgia towards the East. Analyzing the aesthetic characteristics of Hanae Mori's clothes what kinds of aesthetic characteristic that her work had and what kinds of influences that she made in the modern fashion would provide substantial contribution of the world's modern fashion. This study provided forms and remarkable features of Japanese traditional custom, revealed Hanae Mori's life and her philosophies of fashion, and defined Hanae Mori's aesthetic characteristics by analyzing her work from 1970's until the retirement, July 2004. Methods of this study are completed by documentary records of Hanae Mori, research papers and fashion magazines that are published domestically and internationally, and collected materials from internet. The results of analysis are epitomized as below. Hanae Mori was the first Japanese fashion designer who expressed the characteristics of traditional Japanese custom with modernity sprit. In the 60's and 70's, especially in the U.S. and European fashion market, she inspired western fashion designers by her original sprit of art: combining Japanese tradition which showed distinctive color and spirit of nature and the western beauty. Hanae Mori created new dress molding from the Kimono's unstructured feature. Her layered look dressing, oblique adjustment and Obi, and others all enabled Mori to express Japanese image into modern fashion. Additionally, in terms of traditional Japanese image being acknowledged world-widely, she played a major contribution in world fashion by suggesting a new vision and raised several sensations in fashion artistry and modeling. Amongst her various patterns, Hanae Mori had butterfly patterns in most of her works, which was her representative symbol. This spoke for her strong will and senses of duty that wanting to inform beauty of Japanese women who were reflected in modern and graceful butterfly patterns. Flowers were another element that symbolized Mori. Using various flower motifs that bloomed in every different four seasons, she connected two images into her fashion; beauty of the nature and enlightening image of vibrating life. The aesthetic characteristics of Hanae Mori's clothes were defined as five: Japonism, naturalism, feminism, eroticism, and modernism. Japonism which is the spirit of Japanese, Mori used the concept to connect the East and the West. Naturalism represented harmony of the nature and the human. Feminism highlighted Eastern women's beauty. Eroticism emitted feminine attraction. Modernism represented simplicity and sophistication. Such aesthetic character illustrated Mori's original emotion that was based on Japanese spirit and she combined it with values of the East and the West. From the analysis of Mori's aesthetic characteristics, it is clearly recognizable her feministic beauty is emanated by her original emotion and sensibility.

• Analytical Science and Technology
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• v.18 no.1
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• pp.5-12
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• 2005

It has been established that soft error of high precision electronic circuits can be induced by alpha particles emitted from the naturally occurring radioactive impurities such as U, and Th. As the electronic circuits have recently become lower dimension and higher density, these alpha-particle emitting radioactive impurities have to be strictly controlled. The aim of this study is to develop of NAA (Neutron Activation Analysis) and gamma-spectrometry to improve the analytical sensitivity and precision of U and Th. A new NAA method has been established using the HTS (Hydrulic transfer system) irradiation facility which has been used to produce radioisotopes for industries and medicines instead of the PTS (pneumatic transfer system) irradiation facility which has been used in general NAA. When the ultratrace impurities have to be analyzed by NAA, background gamma-ray spectra induced from $^{222}Rn$ and its progenies in air is serious problem. This unstable background has been eliminated or stabilized by the use of a nitrogen purging system. Ultra trace amounts of U (0.1 ng/g) and Th (0.01 ng/g) in high purity silica used for EMC could be analyzed by the use of HTS-NAA and low background gamma-spectrometry.

• Archives of design research
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• v.18 no.1 s.59
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• pp.59-68
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• 2005

In 20th century, that is the times of mass production with mass consumption, a company supplies standard product by the system of mass production line. Therefore, the company, itself, had to introduce its product quality to the customers. It was the buying criterion of consumer against product. In that period, a company utilized its identity in order to give customers product information such as product value, price and quality, etc. However, as digital technology with the wide-spread of informationalization & technical revolution is developed, products have diversification and customers have better incomes. So, buying method tends to thi purchase of self-satisfaction generally. In the buying criterion of consumerbased on personality & sensibility, a company must offer the buying criterion of product which can appeal the special quality & image of product itself to customers, and it must stop appealing the Cl of company under the condition of mass production by product quality and function. This study tried to focus on the method which can create effective brand and its image that are the buying criterion of new product. Also, this study tried to find the effective relation between economical & social paradigm which is the result of social informationalization with intensive knowledge, and buying determination of customer, And, this study tried to present guideline of effective brand image and brand special Quality that is affected to buying determination of customers together. The model of Positive analysis had two types. The first model studied the mutual relation between economical/social change factors and special quality of brand. And, the second model studied the mutual relation between the cause of special quality of brand and formation of brand image through regression analysis. Therefore, the construction of sensitive brand image for forming brand must be requested. The sensitive brand image is highly related to preference of sensibility, and it must be based on mind identity & visual identity. And, mind identity must have creation of value, satisfaction, combination of community, personal preference, etc. Visual identity must have esthetic order, and originality of molding, etc. Namely, brand image must form the accommodation of era change, personality & sensibility satisfaction, the effectiveness of service, etc., in order to create effective brand image.

• Conservation Science in Museum
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• v.8
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• pp.49-69
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• 2007

This is about the scientific analysis of the 10 items of the gilt-bronze Panbul excavated from Anapji, Gyeongju. First, the composition of the Panbul was confirmed, using X-ray fluorescence spectrometer (XRF), and the patinas covering the surface of the Panbul were analyzed, using X-ray diffractometer (XRD). And the micro structures and gilt layer of the Panbul were investigated, using microscope and scanning electron microscope with energy dispersive spectrometer (SEM/EDS), and in order to investigate the internal conditions of the Panbul, X-radiography was conducted. As the result, it is found out that the material of the Panbul excavated from Anapji was the bronze of copper (86~95%) and tin (4~12%), and coated with gold. And cuprite (Cu₂O) was detected from red patina of the gilt-bronze Panbul, and chalcocite(Cu₂S) also was detected from the black patina. As the result of the observation of the micro structure through microscope, it is estimated that it was manufactured, using the wax molding method, and, judging from the fact that the thickness of gilt layer was not even, and that the groove had been filled, it was presumed that the amalgam coating method had been used, but some questions still remain, because mercury was not detected. Lastly, through the X-radiography, it was observed that the tiny round spots existed, which was presumed to have been generated during the casting.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.117-121
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• 2009

Soybean curd (SC) is prepared through the elimination of water-insoluble components and molding by pressing. However, whole soybean curd (WSC) is made without the elimination of water-insoluble components and pressing. Therefore, it was considered that the components contained in WSC might be different from those in SC and we compared their contents of various components, hardness, and morphological features for this study. Ash, dietary fiber, and niacin contents were significantly higher in WSC than in SC. In addition, the carbohydrate and vitamin $K_1$ contents of WSC tended to be higher than those in SC, whereas the hardness of WSC was lower than that of SC. Moreover, electron microscopic analysis showed that the morphological characteristic of WSC consisted of considerably more fine retiform tissues in comparison to SC. Based on their compared nutrition, functional, and quality characteristics, it was suggested that WSC might be superior to SC.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.3
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• pp.31-35
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• 2013

TSOP(Thin Small Outline Package) is the IC package using lead frame, which is the type of low cost package for white electronics, auto mobile, desktop PC, and so on. Its performance is not excellent compared to BGA or flip-chip CSP, but it has been used mostly because of low price of TSOP package. However, it has been issued in TSOP package that thermal deflection of lead frame occurs frequently during molding process and Au wire between semiconductor die and pad is debonded. It has been required to solve this problem through substituting materials with low CTE and improving structure of lead frame. We focused on developing the lead frame structure having thermal stability, which was carried out by numerical analysis in this study. Thermal deflection of lead frame in TSOP package was simulated with positions of anti-deflection adhesives, which was ranging 198 um~366 um from semiconductor die. It was definitely understood that thermal deflection of TSOP package with anti-deflection adhesives was improved as 30.738 um in the case of inside(198 um), which was compared to that of the conventional TSOP package. This result is caused by that the anti-deflection adhesives is contributed to restrict thermal expansion of lead frame. Therefore, it is expected that the anti-deflection adhesives can be applied to lead frame packages and enhance their thermal deflection without any change of substitutive materials with low CTE.

• Korean journal of food and cookery science
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• v.19 no.4
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• pp.454-462
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• 2003

Recently, the HACCP(Hazard Analysis Critical Control Point) system has been emphasized in food processing industries throughout the world. However, the system has, as yet, not been applied very well to domestic food industries. Due to the increase in the consumption of bakery products, more studies are required on the application of HACCP to establish the system in small-scale bakeries. This study was designed to provide basic data for setting management standards for HACCP, based on microbiological hazard evaluations of bakery products. Red bean paste filled breads, custard cream filled breads and cakes covered with fresh whipping cream were collected, and microbiological evaluations conducted on the raw materials, the manufacturing processes and potential hazards. The result showed the presence of coliforms in fresh cream of cakes and the soybean paste of soybean paste breads at levels as high as 105 CFU/g on the hazard analysis of the raw materials. Moreover, the general levels of bacteria and coliforms were over those of the standards during the intermediate fermentation and molding processes. Furthermore, high levels of coliforms were detected on the hands of the salesmen and bakers themselves. This suggests that the CCPs (Critical Control Points), such as fresh cream and red bean paste manufacturing process desperately require better management. There is also a requirement for education relating to personal hygiene for the production of hygienic bakery products and for the publics health.

• Clean Technology
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• v.24 no.4
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• pp.280-286
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• 2018

In this study, the adsorption performance of vapor phase VOCs under dry conditions was evaluated by using two metal oxides, $TiO_2$ powder and $Al_2O_3$ powder. BET analysis and ammonia in-situ FT-IR analysis were used to analyze specific surface area and surface acid site. As a result, $TiO_2$ powder and $Al_2O_3$ powder had a specific surface area of $317.6m^2\;g^{-1}$ and $64m^2\;g^{-1}$, respectively. In the case of $TiO_2$ powder, many acid sites were observed on the surface. As a result of evaluating the vapor phase VOCs adsorption performance using two metal oxide powders, $TiO_2$ powder having a relatively large specific surface area and a large number of acid sites exhibited relatively good adsorption performance. In particular, it is considered that the specific surface area directly affects the adsorption performance, and further study on the effect of the acid site is required. Based on the $TiO_2$ exhibited excellent adsorption performance, it manufactured into various forms of honeycomb, hollow fiber and disc. As a result, the adsorption performance was lower than that of the powder, but it is advantageous in view of applicability. In addition, it was confirmed that the disc adsorbent having excellent thermal durability due to the characteristics of the manufacturing process stably maintains adsorption performance even at a high temperature desorption process several times.