• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.32-38
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• 2014

In the present study, immersion corrosion characteristics of Zn and Al thermal spray coating with sealer for the seawater heat exchanger are experimentally investigated. Total 8 coating types of Zn and Al thermal spray coating with silicone and epoxy sealer were tested with immersion corrosion testing in $80^{\circ}C$ 3.5%w NaCl solution and compared the corrosion characteristics between each coatings. To investigate the corrosion characteristics of the specimens, AC impedance, SEM, and thermal diffusivity were acquired and analyzed. As a result, on the surface of the specimens with silicone and epoxy sealer, blister did not occurred, so the sealers might be effective at increasing the corrosion resistance of the specimens immersed in the NaCl solution.

• Journal of Korea Multimedia Society
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• v.11 no.2
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• pp.257-268
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• 2008

Multimedia recommendation systems analyze user preferences and recommend items(multimedia contents) to a user by predicting the user's preference for those items. Among various kinds of recommendation methods, collaborative filtering(CF) has been widely used and successfully applied to practical applications. However, collaborative filtering has two inherent problems: data sparseness and the cold-start problems. If there are few known preferences for a user, it is difficult to find many similar users, and therefore the performance of recommendation is degraded. This problem is more serious when a new user is first using the system. In this paper, we propose a method of generating additional feature of users and items into CF to overcome the difficulties caused by sparseness and improve the accuracy of recommendation. In our method, we first generate additional features by using the probability distribution of feature values, then recommend items by applying collaborative filtering on the modified data to include additional features. Several experimental results that show the effectiveness of the proposed method are also presented.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.413-418
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• 2006

개인용 미디어 단말로서 MP3 플레이어는 이제 음악 파일을 감상하기 위한 일상 생활에서 중요한 휴대 필수품이 되었으며 단순히 음악을 재생하는데 그치지 않고, 각종 정보들을 표시하기 위한 작은 화면이 부착되고 있으며 더 나아가 이미지 정보나 동영상을 표현할 수 있는 기능들이 추가 되고 있다. 이처럼 변화하는 멀티미디어 서비스에 발맞추어 MPEG 에서는 Multimedia Application Format (MAF) (ISO/IEC 23000) 라는 새로운 표준안을 제안하였다. MAF 표준안의 기본 방식은 산업 현장 및 사용자의 요구에 빠르게 부응하기 위해, 기존에 존재하는 표준안들을 결합시켜 새로운 멀티미디어 파일 포맷을 정립하였다. 그 첫 번째 결과물로서, 이미 널리 쓰이고 있는 MP3 파일 포맷에 새로운 기능을 추가하기 위한 Music Player MAF 포맷의 FDIS 가 제안되었다. Music Player MAF 는 MPEG-1 Audio Layer III(MP3) 와 MPEG-7 MDS 메타데이터 정보를 결합한 파일 포맷으로. 기존 ID3 태그에서 표현되는 정보 보다 훨씬 풍부한 메타데이터 정보와 더불어 선택적으로 하나의 JPEG 이미지를 포함한 형태로 이루어져 있다. 그러나, 현재의 파일 포맷은 시간이 고려되지 않은 하나의 JPEG 이미지만을 포함할 수 있기 때문에, 오늘날 사용자가 요구하는 다양한 멀티미디어 서비스를 제공하기에는 많은 한계점을 갖고 있다. 본 논문에서는 Music Player MAF FDIS 에 제안된 세가지 형태의 Music Player MAF 파일 포맷에 관해 기술 한다. 복수의 JPEG 이미지 및 텍스트를 저장하기 위하여 각각의 파일 포맷이 갖는 문제점을 언급하고 하나 이상의 JPEG 이미지와 자막 정보를 MP3 음악 정보와 동기화 시켜 추가 할 수 있는 기능을 추가를 제안한다. 또한 제안된 파일 포맷을 쉽게 생성할 수 있도록 기존의 XMT-O 스키마를 기반으로 MAF 를 위하여 새롭게 MAF XMT 스키마를 정의하고 정의된 스키마를 기반으로 구현된 Music Player MAF 의 저작툴과 제안된 확장 뮤직 플래이어 MAF 을 위한 재생툴을 구현한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.194-195
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• 2012

박막 실리콘 태양전지에 입사한 빛 중 흡수층인 진성 비정질 실리콘층(i-a-Si)에 흡수된 빛은 출력으로 변환되나, 기타의 층에서 흡수된 빛은 손실 성분이 된다. 이 중 흡수 손실이 큰 층은 도핑 층(p-a-SiC 및 n-a-Si)들인데, 이 들의 흡수 손실을 측정된 광학함수를 이용해 계산해 보면 Fig. 1과 같이 나타난다. p-a-SiC은 광 입사부에 위치하여 단파장 영역의 흡수 손실을 일으키고, n-a-Si 은 태양전지의 후면에 위치하여 장파장 영역의 흡수손실을 일으킨다. 이러한 도핑층에서의 흡수 손실을 제거 또는 개선하기 위해 도핑층의 재료를 기존 재료보다 광학적 밴드갭이 큰 재료로 대체하여 개선하는 방안에 대해 논하고자 한다. 금속 산화물의 밴드갭은 실리콘 화합물에 비하여 대체로 큰 값을 가지기 때문에 이를 기존의 실리콘 화합물 대신으로 사용한다면 광학적 흡수 손실을 효과적으로 줄일 수 있다. 단, 이때 태양전지의 광 전압을 결정하는 인자가 p층과 n층 사이의 일함수 차이에 해당하므로, p층의 대체층으로 사용 가능한 금속 산화물은 일함수가 큰(＞5 eV) 재료 중에서 선택하는 것이 적합하며, n층의 대체층으로 사용 가능한 금속 산화물은 일함수가 작은(＜ 4.2 eV) 재료 중에서 선택하는 것이 적합하다. Table 1에서 p층과 n층 대체용 금속산화물의 후보들을 정리하였다. 먼저 도핑층에서의 광 흡수가 광손실이 될 수 밖에 없는 물리적 근거에 대해서 논하고, 그 실험적인 증명을 제시한다. 이러한 개념을 바탕으로 도핑층의 내부 전기장의 방향을 제어하여 전자-정공쌍을 분리 수집하는 방법을 실험적으로 구현하였다. 이어서 금속 산화물을 부분적으로 대체하여 흡수 손실을 개선하는 방안을 제시한다. WOx, NiOx, N doped ZnO 등을 적용하여 그 효과를 비교 검토하였다. 끝으로 금속산화믈 대체 또는 쇼트키 접합을 적용하여 도핑층의 광 흡수를 줄이고 효율을 향상하는 방안을 제시한다. 그 사례로서 WOx, MoOx, LiF/Al의 적용결과를 살펴보고 추가 개선방안에 대해 토의할 것이다. 결론적으로 광학적 밴드갭이 큰 재료를 도핑층 대신 사용하여 흡수 손실을 줄이는 것이 가능하다는 것을 알 수 있고, 이 때 일함수 조건이 만족이 되면 광 전압의 손실도 최소화할 수 있다는 점을 확인할 수 있었다. 현재까지 연구의 한계와 문제점을 정리하고, 추가 연구에 의한 개선 가능성 및 실용화 개발과의 연관관계 등을 제시할 것이다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.177-185
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• 2015

City-based Lifeline is expected to cause significant social and economic loss accompanied the secondary damage such as paralysis of urban functions and a large fire as well as the collapse caused by earthquake. Earthquake Disaster Response System of Korea is being operated with preparation, calculates the probability of failure of the facility through Seismic Fragility Model and evaluates the degree of earthquake disaster. In this paper, the time history analysis of buried gas pipeline in city-based lifeline was performed with consideration for ground characteristics and also seismic fragility model was developed by maximum likelihood estimation method. Analysis model was selected as the high-pressure pipe and the normal-pressure pipe buried in the city of Seoul, Korea's representative, modeling of soil was used for Winkler foundation model. Also, method to apply developed fragility model at GIS is presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1212-1217
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• 2017

We constructed a population of myelinated cells with co-culture of neuronal cells and Schwann cells from DRG. Schwann cells and neuronal cells were isolated from dorsal root ganglion (DRG) in embryos of rat in vitro respectively. The cultured Schwann cells and cultured neuronal cells, respectively were co-cultured in a same plate. This procedure contains following four steps: first step of suspension of the embryonic dorsal root ganglion cells, second step of addition of anti-mitoticcocktail, third step of purification of dorsal root cells, and fourth step of addition of Schwann cells to dorsal root ganglion cells. These cells were performed accomplishment of myelination. This myelinated co-culture system was infected by Semliki forest virus and then induced demyelination processing in this myelinated co-culture. We identified myelination and demyelination processing using antibody of peripheral myelin protein 22 (PMP 22) meaning presence of myelinated neuron.

• Culinary science and hospitality research
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• v.15 no.4
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• pp.159-171
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• 2009

A geographical indication is a protected trade name or mark for a product that corresponds to a specific geographic location or origin. Geographical indications have been widely used in European countries over the last three decades, mainly for wine and food products. This study investigates the consumer perception of geographical indications for agricultural and processed products and purchase experiences of consumers. It also examines consumer intention to pay more for geographical indication products. The findings from the empirical investigation showed that only 24.0% of the respondents have purchased geographical indication products whereas 49.5% of the respondents have not. Meanwhile, 26.5% of the respondents reported that they were unaware of geographical indications. Main reasons of purchasing geographical indication products were trust in quality, safety, and better taste. On the other hand, main reasons of not purchasing geographical indication products were lack of knowledge and no distinctive quality. The respondents answered that they would pay more for geographical indication products especially for luxury items such as ginseng, wine, and beef.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.213-220
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• 1998

An ATP regeneration system was used for the production of glutathione which was synthesized by a sequential action of ${\gamma}$-glutamyl-cysteine synthetase and glutathione synthetase. The synthetases above were produced in the recombinant E. coli (TG1/pDG7) with the highest specific production yield of 31 mg glutathione/g wet cell. Bakers yeast was considered to have economically a better ATP regeneration system although the glutathione production yield was lower than that of acetate kinase. It was also observed that the ATP regeneration system of bakers yeast was superior to that of Saccharomyces cerevisiae ATCC24858. The yield of glutathione production with bakers yeast was 36% with the ATP concentration of 5 mM. To avoid the cysteine limitation during the early phase of glutatione production, an extra cysteine was added at 2 hours after reaction and the production yield increased 1.91 times. The effectiveness of bakers yeast as an ATP regeneration system was proved by several sets of extra feeding experiments. The product inhibition by glutathione above 14 mM was also observed.

• Journal of the Korean Society of Radiology
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• v.9 no.4
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• pp.249-255
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• 2015

In this study, through the additional information of the PET / CT images by utilizing the basic data of TPS clinical application on the basis of the image re-forming synthetic function, the True-D technology and MIM software for continued research and development in combination, based on the combination-work between the respective images, reducing the time and cost of useful reading in clinical wide use of image width, efficient, effective tool for tumor targeting at diagnosis and radiation therapy by use as, by using the precise therapeutic effect determination, the time taken to read in the clinical, unnecessary and expect to a can reduce the additional examination by the creation of tumor patients read reports and PACS such asWe expect to be utilized for compatibility development with other software to evaluate the performance of PET / CT equipment.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.97-101
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• 1983

A study was conducted to investigate possibility of utilizing dried citrus peel (DCP) as an ingridient of broiler diets. Fresh citrus peels were collected from a citrus processing plant, and were sun-dried and ground. Both chemical analyses and a feeding trial were carried out. DCP was analyzed for proximate nutrients, amino acids and some minerals. In the feeding trial, a total of 192 day-old female broiler chicks of Manor strain was divided into 16 groups of 12 birds each. Each group was fed one of the 4 different levels(0, 2, 4 and 6%) of DCP replacing an equivalent amount of wheat bran in the diet with 4 replications for 6 weeks. Body weight gain, feed intake and feed efficiency of broilers fed different levels of DCP showed no significant differences among treatments. Immediately after termination of the feeding trial, cach bird was examined for shank color using Roche's Egg Yolk Color Fan. Shank color index of birds increased consistently (P＜0.05) as the level of DCP fed increased, indicating that DCP can be used as a source of pigments. It was concluded from the results that DCP could be used up to 6% in place of wheat bran in broiler diets without adverse effects.