• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.431-432
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• 2012

In the era of 20 nm scaled semiconductor volume manufacturing, Microelectronics Manufacturing Engineering Education is presented in this paper. The purpose of microelectronic engineering education is to educate engineers to work in the semiconductor industry; it is therefore should be considered even before than technology development. Three Microelectronics Manufacturing Engineering related courses are introduced, and how undergraduate students acquired hands-on experience on Microelectronics fabrication and manufacturing. Conventionally employed wire bonding was recognized as not only an additional parasitic source in high-frequency mobile applications due to the increased inductance caused from the wiring loop, but also a huddle for minimizing IC packaging footprint. To alleviate the concerns, chip bumping technologies such as flip chip bumping and pillar bumping have been suggested as promising chip assembly methods to provide high-density interconnects and lower signal propagation delay [1,2]. Aluminum as metal interconnecting material over the decades in integrated circuits (ICs) manufacturing has been rapidly replaced with copper in majority IC products. A single copper metal layer with various test patterns of lines and vias and $400{\mu}m$ by $400{\mu}m$ interconnected pads are formed. Mask M1 allows metal interconnection patterns on 4" wafers with AZ1512 positive tone photoresist, and Cu/TiN/Ti layers are wet etched in two steps. We employed WPR, a thick patternable negative photoresist, manufactured by JSR Corp., which is specifically developed as dielectric material for multi- chip packaging (MCP) and package-on-package (PoP). Spin-coating at 1,000 rpm, i-line UV exposure, and 1 hour curing at $110^{\circ}C$ allows about $25{\mu}m$ thick passivation layer before performing wafer level soldering. Conventional Si3N4 passivation between Cu and WPR layer using plasma CVD can be an optional. To practice the board level flip chip assembly, individual students draw their own fan-outs of 40 rectangle pads using Eagle CAD, a free PCB artwork EDA. Individuals then transfer the test circuitry on a blank CCFL board followed by Cu etching and solder mask processes. Negative dry film resist (DFR), Accimage$^{(R)}$, manufactured by Kolon Industries, Inc., was used for solder resist for ball grid array (BGA). We demonstrated how Microelectronics Manufacturing Engineering education has been performed by presenting brief intermediate by-product from undergraduate and graduate students. Microelectronics Manufacturing Engineering, once again, is to educating engineers to actively work in the area of semiconductor manufacturing. Through one semester senior level hands-on laboratory course, participating students will have clearer understanding on microelectronics manufacturing and realized the importance of manufacturing yield in practice.

• Journal of Biosystems Engineering
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• v.42 no.2
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• pp.112-116
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• 2017

Purpose: The purpose of this study was to analyze the milling characteristics of white rice depending on the guide angles of the cutting roller's induced guide, as well as to verify optimum milling conditions for the cutting-type milling machine. Methods: Brown rice, which was produced in Cheongju-si, Chungcheongbuk-do, Republic of Korea, in 2014, was used as the experimental material. The milling characteristics of white rice were measured under six different guide angle levels of the cutting roller, which were none, $0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$, and $20^{\circ}$. The quantity of brown rice for each experiment was 500 kg, and the milling characteristics were measured according to the whiteness, rice temperature, cracked rice ratio, broken rice ratio, and energy consumption. Results: The whiteness of white rice maintained a uniform level, indicating at range of $38{\pm}0.5$, regardless of the cutting roller guide angles under all conditions. The rice temperature rise during milling was found to be rather low, at $13.9^{\circ}C$ and $13.6^{\circ}C$ at $10^{\circ}$ and $15^{\circ}$ guide angles, respectively. The cracked rice ratio after milling was 18.67%-19.47%, and the broken rice ratio was 0.68% at a $10^{\circ}$ guide angle, which is the lowest in comparison to other guide angles. Energy consumption was lower when the guide was used compared to that with-out the use of the guide. The energy consumption tended to increase as the cutting roller guide angle increased. Conclusions: From the above results, we conclude that the cutting roller guide angles of $0^{\circ}$ and $10^{\circ}$ are suitable for producing high quality rice during milling with a cutting-type milling machine.

• Journal of the Korean Home Economics Association
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• v.43 no.5 s.207
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• pp.183-198
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• 2005

The purpose of this study was to discuss the relationship between Korean people's normative sense of the traditional filial piety and their affiliation with relatives. For this purpose, the researcher reviewed ethics books during the Chosun dynasty such as Naehoon Women's Ethics), Dongmongsonsup (Children's Cardinal Moral Principles) ,Kyokmongyokyol (Juvenile's Learning) and Gyuenyoso (Instructions for Daughters of Marriageable Age), Based on this review a questionnaire was designed. For the survey,566 returned questionnaires from married people between their 20's and 70's living in Seoul and Wonju Si were sampled The collected data were analyzed using the SAS program for means and SDs of each area in order to examine the overall tendency, and were subject to one-way ANOVA to determine the relationship between their normative sense of the traditional filial piety and their affiliations with relatives depending on their demographic variables, In addition to this correlation analysis, the data underwent regression analysis to determine the significant factors affecting the subjects' sense of filial piety and their affiliation with relatives. The results of this study can be summarized as follows ; First, the subjects were found to have a normal or higher sense of filial piety in overall terms, which suggests that the Korean morality of filial piety may be positive. In particular, the subjects' sense of filial piety was higher for living parents than for dead ones. Namely, they wanted to give more respect, honor and support to their parents than give a cordial funeral or memorial service to deceased parents. Second, older Koreans were more aware of filial piety, and men were more conscious of filial piety than women. Buddhists or atheists tended to be more faithful to their parents. Generally, those with lower academic background and living with larger families had a higher normative sense of filial piety. On the other hand, those in their 60's and 70's were most affiliated with their relatives, while youth and middle-aged people were less affiliated with their relatives. Men were more affiliated with their relatives than women, and first sons or daughters were more affiliated with their relatives. Besides, those living with larger families were more affiliated with their relatives. Third, the subjects' normative sense of filial piety, particularly for deceased parents, was highly correlated with their affiliation with relatives, and such a normative sense of filial piety was most conspicuous in their funeral rites.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.578-588
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• 2017

Background: Elevated testicular temperature disrupts spermatogenesis and causes infertility. In the present study, the protective effect of enzymatically biotransformed Panax ginseng Meyer by pectinase (GINST) against chronic intermittent heat stress-induced testicular damage in rats was investigated. Methods: Male Sprague-Dawley rats (4 wk old, 60-70 g) were divided into four groups: normal control (NC), heat-stress control (HC), heat-stress plus GINST-100 mg/kg (HG100), and heat-stress plus GINST-200 mg/kg (HG200) treatment groups. Each dose of GINST (100 mg/kg and 200 mg/kg) was mixed separately with a regular pellet diet and was administered orally for 24 wk. For inducing heat stress, rats in the NC group were maintained at $25^{\circ}C$, whereas rats in the HC, HG100, and HG200 groups were exposed to $32{\pm}1^{\circ}C$ for 2 h daily for 6 mo. At week 25, the testes and serum from each animal were analyzed for various parameters. Results: Significant (p < 0.01) changes in the sperm kinematic values and blood chemistry panels were observed in the HC group. Furthermore, spermatogenesis-related molecules, sex hormone receptors, and selected antioxidant enzyme expression levels were also altered in the HC group compared to those in the NC group. GINST (HS100 and HS200) administration significantly (p < 0.05) restored these changes when compared with the HC group. For most of the parameters tested, the HG200 group exhibited potent effects compared with those exhibited by the HG100 group. Conclusion: GINST may be categorized as an important medicinal herb and a potential therapeutic for the treatment of male subfertility or infertility caused by hyperthermia.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.341-352
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• 2011

Colibacillosis in pigs remain a major swine industry bruden worldwide. Although some progress has been made in treating collibacillosis in pigs by using biosecurity and antimicrobials, it still remain a considerable problem. The use of host-specific bateriophages as a biocontrol is one possible alternative. The purpose of this study was to evaluate the effect of bacteriophage against enterotoxigenic Escherichia coli (ETEC) K88 infection in piglets. Twenty-eight piglets were randomly divided into four groups and each group was allocated with 7 pigs. Group B, C and D were inoculated with 5 ml of ETEC K88 ($1{\times}10^8$ CFU/ml) per head of piglet via oral. Group C and D were fed with bacteriophages (Group C, $1.0{\times}10^6$ PFU/g; Group D, $1.0{\times}10^8$ PFU/g; CJ CheilJedang Corp., Korea) orally as treatment. In piglets administrated bacteriophages and challenged with ETEC K88 (Group C and D), Clinical signs and the growth performance were improved and antibody titers were maintained low level compared with piglets challenged with ETEC K88 (Group B, P<0.05). Group B were shown high pH in the alimentary tracts compared with other piglets (P<0.05). In quantitative analysis by real-time PCR, the results of Group C and D were lower than those Group B in faecal and intestinal samples (P<0.05). Severe villus atrophy and crypt hyperplasia were observed in Group B consequently V/C ratio increased, compared with other piglets. These results indicate that feeding with bacteriophage has effect to prevent ETEC K88 infection in piglets and suggest that use of bacteriophage can be considered a valid antibiotic alternative.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1612-1617
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• 2009

Aspergillus sp. 101 was isolated from the Korean traditional soybean paste for the production of a salt-tolerant protease. The optimal condition for the production of a salt-tolerant protease was determined with various energy sources such as carbon, nitrogen, and protein, and at different culture conditions such as temperature, pH, incubation time and NaCl concentration. The most favorable organic nitrogen sources were 2% defatted soybean flour (DSF) and soy protein isolate (SPI). Optimal pH and temperature were pH 6.0 and $25{\sim}27^{\circ}C$, respectively. Therefore, Aspergillus sp. 101 protease was a mild acid (or neutral) protease. Protease production was the highest at 0.1% concentration of $CaCO_3,\;K_2HPO_4$ and Arabicgum. Aspergillus sp. 101 could grow in culture medium at 15% NaCl concentration and produce a salt-tolerant protease even at 7% NaCl. The cell mass and protease activity of Aspergillus sp. 101 cultured in a modified medium was comparatively higher in Czapek dox and protease producing media. Hence, Aspergillus sp. 101 protease can be utilized in soy or fish sauce industry as a salt-tolerant protease starter.

• Journal of Adhesion and Interface
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• v.11 no.3
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• pp.120-125
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• 2010

UV-curable acrylic Pressure-sensitive adhesives (Acrylic PSAs) are used in many different parts in the world. A wafer manufacture process which is based on semiconductor industry is one thing. We have used acrylic PSAs whose thickness is different from $20{\mu}m$ to $30{\mu}m$ in wafer manufacture process so far. But as wafers become more thinner, acrylic PSAs are supposed to satisfy the requirements such as proper adhesion performance. The main purpose of this research is studying proper adhesion performance and UV-curing behavior of UV-curable acrylic PSAs with very thin thickness and then determining optimized conditions to raise the efficiency of thin wafer production. Acrylic PSAs contain 2-Ethylhexyl Acrylate (2-EHA), Acrylic Acid (AA) and Butyl Acrylate (BA). Ethyl acetate (EtAc) is used as solvent. The acrylic PSAs are obtained using solvent polymerization. Thickness of UV-curable acrylic PSAs is different from $10{\sim}30{\mu}m$. By peel strength and probe tack, adhesion performance and UV curing behavior of acrylic PSA are concerned.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.499-504
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• 2005

Polymer concrete shows excellent mechanical properties and chemical resistance compared with conventional normal cement concrete. The polymer concrete Is drawing a strong interest as high-performance materials in the construction industry Resins using recycled PET offer the possibility of a lower source cost of materials for making useful polymer concrete products. Also the recycling of PET in polymer concrete would help solve some of the solid waste problems Posed by plastics and save energy. An objective of this paper is to estimate the damage of sulfuric acid, through investigating recycled PET polymer concrete, immersed at sulfuric acid solution for 84 days. As a result of testing, recycled PET PC, used $CaCO_3$ as filler, makes a problem of appearance and strength if they are exposed for long term at corrosion environment. On the other hand, recycled PET PC, used fly-ash as filler, had less effect on decrease in weight and strength. Recycled PET PC is excellent chemical resistance, resulting in the role of unsaturated polyester resin which consists of polymer chain structure accomplishes bond of aggregates and filler strongly. Also, recycled PET PC, used fly-ash as filler, is stronger resistance of sulfuric acid corrosion than $CaCO_3$, because it is composed of $SiO_2$ and very strong glassy crystal structure. Therefore, recycled PET PC, used fly-ash as filler, is available under corrosion circumstances like sewer pipe or waste disposal plant.

• Resources Recycling
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• v.19 no.6
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• pp.43-50
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• 2010

The crisis of energy gives rise to the growing concerns over continuing uncertainty in the energy market. Under these circumstances, there are also increasing interests on coals. In particular, Low Rank Coal (LRC) is receiving gradual attentions from green industry. But due to is high moisture content range from 30 - 60%, drying process has to be preceded before being utilized as power plant. In this study drying kinetics of LRC is induced by using a fixed-bed reactor. The drying kinetics was evaluated in from of the particle size, the inlet gas temperature, the drying time, the gas velocity, and the LID ratio. The consideration of the reynold's number was taken for correction of gas velocity, particle size and LID was taken for correction of reactor diameter, packing height of coal. As being seen as characteristic of drying coal, it can be found that fixed-bed reactor can contributed to active drying of free water. In this sense, it could be considered that phase boundary reaction is appropriate mechanism.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.492-492
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• 2018

'물발자국(Water Footprint)' 개념은 가상수의 개념이 확장된 것으로 제품 생산과 서비스 전 과정에서 사용된 물의 양을 나타낸다. 따라서 한 국가내의 수자원 총량의 산출 시에 국제 무역을 통해 수출-수입되는 가상수의 양까지 고려하여 국가 물 총합(Water Budget)을 계산한다. 본 연구는 가상수의 수자원 활용에 관한 산업적 차원의 비교를 위하여 산업별 물발자국 산정모델을 구축하고자 하였다. 산업별 물발자국을 산정하기 위하여 첫째, 산업별 용수사용량에 기초하여 물발자국을 산정하였고, 둘째, 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 먼저 산업별 용수사용량에 기초한 물발자국 산정은 하향식 접근법을 적용하였다. 국가 산업별 물발자국을 산정한 결과, 산업 전체 물발자국은 약 330억$m^3$이며 그 중 농업계가 연간 118.8억$m^3$으로 전체 물발자국의 36%를 차지하였다. 그 다음은 생활계로 전체의 34%인 111억 4천만$m^3$이다. 축산계의 물 사용량은 연간 2억 6천 7백만$m^3$ 정도이지만, 오염물질을 정화하는데 필요한 물인 회색수의 양이 많아 물발자국이 73억 $m^3$으로 비교적 높게 산정되었다. 공업계의 가상수량은 연간 26억$m^3$으로 타 산업에 비하여 오염부하량이 높지 않아 회색수량이 작게 나타났다. 다음으로 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 단위 물발자국과 생산량을 활용하여 산정하는 상향식 접근법을 활용하였다. 1980년대부터 2014년까지 쌀 외 18개 품목에 대한 농산물 생산의 물발자국을 산정한 결과, 전체 물발자국은 평균 90억$m^3$으로 추정되었다. 한편, 2차 산업의 물발자국은 산업연관분석을 활용하여 산정하였다. 산업연관분석을 위하여 한국은행의 산업연관표와 경제총조사의 용수비 항목을 활용하였다. 2차 산업의 총 물발자국을 산정한 결과, 60억 $m^3$으로 추정되었다. 3차 산업의 물발자국도 이와 동일한 방식으로 산업연관표를 활용하여 산정하였다. 산업연관분석을 활용한 3차 산업의 물발자국 산정한 결과, 숙박 및 음식점업에서의 물발자국이 가장 큰 것으로 산정되었다. 이에 따라 Case Study로서 국내 워터파크 대상으로 물발자국을 산정하였다. 자료가 없는 부분을 제외하고 연간 총 840만 $m^3$의 물발자국을 가지는 것으로 나타났으며, 이 중 직접수는 70만 $m^3$, 간접수는 770만 $m^3$으로 간접수의 비율이 92%를 차지하였다.