• 대한치과보철학회지
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• 제42권6호
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• pp.619-627
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• 2004

Statement of problem. Mechanisms of tissue-implant interaction and the effect of the implant surface on the behavior of cells has not yet been clarified. Purpose. This study was performed to investigate the tissue reaction to the titanium alloy submerged into rat peritoneum in vivo. Materials and methods. Titanium alloys (titanium-13Zirconium-6Niobium) were inserted inside the peritoneal cavity of Sprague Dawley rats. After 3 months, the tissue formed around the inserted titanium alloys were examined with a light-microscope. Tissue reaction around the material was analyzed by confocal microscopy to evaluate their biocompatibility in a living body. Results. In in vivo study, foreign body type multinucleated giant cells were found in the fibrous tissue formed as a reaction to the foreign material (4 in 20 cases), but the inflammatory reaction was very weak. After experiment, the contaminants of biomaterials was removed from living tissue. In confocal microscopy, we observed that the staining of vinculin and actin showed mixed appearance. In a few cases, we found that the staining of vinculin and beta-catenin showed the prominent appearance. Conclusion. We found that titanium-13Zirconium-6Niobium alloy was an excellent biomaterial.

• 한국재료학회지
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• 제11권10호
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• pp.841-845
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• 2001

The steam generator tubes of power plant damaged by sliding wear due to flow-induced motion of foreign object. Amount of wear have been predicted by Achard's wear equation until now. However, there are large error and low reliability, because this equation regards wear coefficient(k) as constant. The sliding wears tests have been performed at room temperature to examine parameters of wear (wear distance, contact stress). The steam generator tube material for wear test is used Inconel 600 and foreign object material is used 304 austenite stainless steel. The sliding wear tests show that the amount of wear is not linearly proportional to the wear distance(for 374 austenite stainless steel). According to experimental result, wear coefficient is not constant k but function k(s) of wear distance. The newly modified wear predictive equation V=k(s)F have small error and high reliability.

• 한국전기전자재료학회논문지
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• 제21권4호
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• pp.348-353
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• 2008

Most of the high voltage insulation systems, such as the power cable joint having hetero interface, are composed of more than two different insulators to improve insulating performance. The partial discharge(PD) in these hetero interface is expected to affect the total insulation performance. Thus, it is important to study electrical properties on these interfaces. This study described the influence of copper and semiconductive substance defects on $\Phi$-q-n distribution between the interface of the model cable joints to classify PD source. PD was sequentially detected for 600 cycles of the applied voltage. The K-means cluster analysis has been analyzed to investigate the $\Phi$-q-n distribution. The skewness-kurtosis(Sk-Ku) plot from K-means clustering results was defined to quantify cluster distribution and classify distribution patterns. The Sk-Ku plot is composed of skewness and kurtosis along abscissa and ordinate which indicate the asymmetry and the sharpness of distribution. As a result of the Sk-Ku plot, it was confirmed that the data was distributed in 1st 2nd and 3rd quadrant at copper foreign substance defect, but in case of semiconductive foreign substance, the data was distributed in 2nd quadrant only.

• 한국의류학회지
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• 제42권3호
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• pp.452-473
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• 2018

This study analyzed the expressions of racing girl uniforms that promote automobile brands shown at Seoul and Busan motor shows. The results are as follows. In each of the design components expression, the glossy and plain material, the achromatic color, and the dress style appeared most frequently in the uniform design of both domestic and foreign automobile brands. In the fashion image expression, sexy image appeared the most, followed by modern image, romantic image, active image, elegance image and ethnic image. Based on the analysis results, the following expressive characteristics were identified: First, sexy images were used in uniform design to express the streamline and speedy feeling of a car metaphorically. Second, modern image, glossy material, and achromatic color were used for a uniform design to express advanced technology and the future orientation of an automobile. Third, fashion images that match the automobile type emphasized the brand image of the car. Fourth, some of the manufacturers that prevailed in the automobile market promoted several automobile brands exhibited with a unified uniform design that expressed the design philosophy and concept. As such, the motor show racing girl uniform contributed to promoting automobile brand identity and the automobile industry.

• 한국전기전자재료학회논문지
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• 제24권3호
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• pp.173-176
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• 2011

The characteristic changes in ZnO thin film according to H- and O- plasma treatments have been studied by Photoluminescence (PL) spectroscopy at room temperature. The red shift of UV peak by 20-30 meV in PL spectra after plasma treatments is identified, which indicates that there are changes in the binding energy of bound exciton and/or the movement of energy levels of lattice defects and impurities. The width of UV peak is decreased after plasma treatments, which is believed to be closely related to the crystal quality of ZnO film. The increase of UV peak intensity after H-plasma treatment is also observed, and this could mean that the radiative recombination is strengthened because the hydrogen atoms in the plasma diffuse into the film where they passivate and neutralize the defects and the impurities.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.105-108
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• 2009

Purpose: Epidermoid cyst may be congenital or acquired. Acquired cysts are most commonly of traumatic origin and result from an implantation or downward displacement of an epidermal fragment. Traumatic epidermoid cysts are rare tumors occurring on the nasal tip, especially resulting aesthetic procedure. So, we report a rare case of an iatrogenic epidermoid cyst in the nasal tip following rhinoplasty. Methods: A 44 - years old man had undergone rhinoplasty for several times. First time, the previous augmentation rhinoplasty and wedge osteotomy were performed nineteen months ago, lastly implant removal and unknown filler injection were performed one year ago at another local clinic. He had induration and tenderness on nasal tip and dorsum continued for 3 months. We thought that it caused by foreign body reaction with residual alloderm in nose. For removal of residual alloplastic material, open approach using transcolumellar incision was done. But, incidentally we found cystic mass on the nasal tip. Results: The findings were of an $0.8{\times}0.5{\times}0.5cm$ sized round cystic mass containing cream coloured material with a thick cheese - like consistency. The mass was completely excised and submitted for histology. This confirmed the diagnosis of an epidermoid cyst lined by keratinizing squamous epithelium. There was no induration, tenderness and sign of recurrence after excision of the mass. Conclusion: Epidermal cyst of the nasal tip region represents an unusual clinical lesion and it presents as foreign body reaction. And then, our case demonstrates that meticulous surgical approach and suture technique are the keys to prevention against iatrogenic nasal epidermoid cyst, especially in secondary rhinoplasty.

• 인터넷정보학회논문지
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• 제25권1호
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• pp.99-107
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• 2024

경제성장과 산업 발전에 따라 반도체 제품부터 SMT 제품, 전기 배터리 제품에 이르기 까지 많은 전자통신 부품들의 제조과정에서 발생하는 철, 알루미늄, 플라스틱 등의 이물질로 인해 제품이 제대로 동작하지 않거나, 전기 배터리의 경우 화재를 발생하는 문제까지 심각한 문제로 이어질 가능성이 있다. 이러한 문제를 해결하기 위해 초음파나 X-ray를 이용한 비파괴 방법으로 제품 내부에 이물질이 있는지 판단하여 문제의 발생을 차단하고 있으나, X-ray 영상을 취득하여 이물질이 있는지 판정하는 데에도 여러 한계점이 존재한다. 특히. 크기가 작거나 밀도가 낮은 이물질들은 X-Ray장비로 촬영을 하여도 보이지 않는 문제점이 있고, 잡음 등으로 인해 이물들이 잘 안 보이는 경우가 있으며, 특히 높은 생산성을 가지기 위해서는 빠른 검사속도가 필요한데, 이 경우 X-ray 촬영시간이 짧아지게 되면 신호 대비 잡음비율(SNR)이 낮아지면서 이물 탐지 성능이 크게 저하되는 문제를 가진다. 따라서, 본 논문에서는 저화질로 인해 이물질을 탐지하기 어려운 한계를 극복하기 위한 5단계 방안을 제안한다. 첫번째로, Global 히스토그램 최적화를 통해 X-Ray영상의 대비를 향상시키고, 두 번째로 고주파 영역 신호의 구분력을 강화하기 위하여 Local contrast기법을 적용하며, 세 번째로 Edge 선명도 향상을 위해 Unsharp masking을 통해 경계선을 강화하여 객체가 잘 구분되도록 한다, 네 번째로, 잡음 제거 및 영상향상을 위해 Resdual Dense Block(RDB)의 초고해상화 방법을 제안하며, 마지막으로 Yolov5 알고리즘을 이용하여 이물질을 학습한 후 탐지한다. 본 연구에서 제안하는 방식을 이용하여 실험한 결과, 저밀도 영상 대비 정밀도 등의 평가기준에서 10%이상의 성능이 향상된다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.330-335
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• 2008

This research aims to investigate the standards and the performances of domestic and foreign windows for and apartment house and to present fundamental data for selecting the optimum window at the step of designing an apartment house. To compare the performances of domestic and foreign windows it is selected 5 major window companies in and 3 major window companies in Japan, and investigated window structure, material, type of opening and closing, window glass and the performances of windows for an apartment house-closing and opening force, repeated closing and opening, thermal resistance, sound transmission loss, air tightness, water tightness, wind resistance. The result of a comparative analysis show that the average thermal resistance of Korean window is higher than Japan's but the average sound transmission loss and water tightness of Korean window is lower than Japan's and the rest of the performances is similar.

• 복식문화연구
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• 제10권3호
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• pp.283-292
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• 2002

This study is to examine the costume and features in Asuka period and the results are as follows. Asuka period is the time that the country loader positively imported the continental civilization, founded a new country organization in political society and accepted Buddhism and exerted his best passion for its thriving. As the result of examining the costume and features of Asuka period when the requirement for accepting the foreign culture was met via the present costume regulation and relics material, it was found that the costume had a considerable difference between of the ruling classes with government official and noble as the center and the common people. As for the costume of the ruling-classed official and noble, Korean and Chinese costume regulation was introduced, court dress, ceremonial dress, and uniform were dressed. The composition of costume with introduction of new clothes including Wio, Baedang, Seup, Pil, Kyongsang, for the ruling classes was diversified as well. As the result of looking the clothes for the present ruling classes via the existing and the contemporary relics, it was found that the clothes consisted of Eui and Gon or Eui and Sang style in principle and Po with Banryung or Sooryung was worn over what. However, for the common people, mainly man wore Eui and Gon and woman Eui and Sang, which was the traditional costume style in the ancient tomb days.

• 한국건축시공학회지
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• 제9권1호
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• pp.111-121
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• 2009

Because of its unique characteristics, the construction industry tends to be affected by economic environment more than any other industries. The domestic construction industry was forced to change its management pattern and system when it went through the foreign currency crisis, and since then, the construction industry has been growing in terms of quality over last 10 years, breaking from the quantitative performance-oriented growth in the past. The study was intended to integrate the financial data of the companies during the period before and after the foreign currency crisis so as to analyze the effect of environmental changes on management performance of the companies. It was aimed at evaluating the changes to the stability, profitability and the growth potential, and collecting the data on variation of the market scale, price of resources such as material and labor and the financial environment, thereby analyzing the correlation with the management performance. The study, to deal with the difficulties which are anticipated, like the foreign currency crisis experienced in the past, was also intended to identify the correlation between the economic conditions and the performance of the construction companies, using the experimental data in the past.