• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제3권2호
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• pp.37-49
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• 1999

In this paper we develop a general Homotopy method called the Group Homotopy method to solve the symmetric eigenproblem. The Group Homotopy method overcomes notable drawbacks of the existing Homotopy method, namely, (i) the possibility of breakdown or having a slow rate of convergence in the presence of clustering of the eigenvalues and (ii) the absence of any definite criterion to choose a step size that guarantees the convergence of the method. On the other hand, We also have a good approximations of the largest eigenvalue of a Symmetric matrix from Lanczos algorithm. We apply it for the largest eigenproblem of a very large symmetric matrix with a good initial points.

• 반도체디스플레이기술학회지
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• 제7권3호
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• pp.41-43
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• 2008

The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied depending on various cell gaps. 5 different cell gaps, such as $1.4{\mu}m,\;1.8{\mu}m,\;2.1{\mu}m,\;2.4{\mu}m$ and $2.8{\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distributions of reflected light and reflectance were calculated with 3-dimmensional LC code. At the center of cell, the smallest $1.4{\mu}m$ cell gap showed the lowest reflectance and the largest $2.8{\mu}m$ cell gap showed the highest reflectance due to the surface anchoring effect. In case of $2.1{\mu}m$ cell gap, the sum of reflectance overall cell was the highest value. Considering the reflectance and RV curve characteristic, the optimized cell gap was $2.1{\mu}m$.

• 한국치위생학회지
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• 제8권4호
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• pp.141-151
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• 2008

The purpose of this study was to examine the oral health awareness and oral health care of health-related and health-unrelated majors in an attempt to stress the importance of oral health education and boost the efficiency of oral health care. The subjects in this study were 363 college students. Out of the selected students, 174 were health-related majors, and 189 weren't. After a survey was conducted, the collected data were analyzed for the purpose of comparison, and the following findings were given: 1. Concerning daily mean toothbrushing frequency, the largest number of the male students who accounted for 55.2 percent brushed their teeth once a day on average, and the greatest number of the female students who represented 52.9 percent did that twice a day. As for the influence of their major, the largest group of the health-related majors who numbered 89(51.1%) brushed their teeth twice a day, and the greatest group of the health-unrelated majors who numbered 93(49.2%) did that once a day. The gaps between them were statistically significant(p<0.05). 2. As to the length of toothbrushing time by gender, it took more than two or three minutes for the largest groups of the male and female students that respectively numbered 96(76.8%) and 184(77.3%) to do toothbrushing(p<0.01). The greatest groups of the male and female students that respectively numbered 72(57.6%) and 183(76.9%) brushed their teeth after meals. 3. In regard to oral hygiene supplies, the largest groups of the health-related and health-unrelated majors that respectively numbered 78(44.8%) and 115(60.8%) had chewing gum and candy with them. As to the use of oral hygiene supplies, 99 health-related majors(56.9%) and 133 health-unrelated majors(70.4%) didn't put oral hygiene supplies to use. Thus, the use of oral hygiene supplies was statistically less common among the health-unrelated majors, and the gap between the two was significant(p<0.01). 4. As for health-related concern by gender, the largest group of the male students that numbered 56(44.8%) showed the most interest in preventing dental caries, and the greatest group of the female students that numbered 103(43.3%) were most concerned about tooth whitening. The gap between the male and female students was statistically significant(p<0.05), but the track of their major made no statistically significant difference to that. 5. Regarding the experience and awareness of scaling, the largest number of the students never got their teeth scaled regardless of gender and major, and the greatest group didn't care about scaling irrespective of gender and major, either, though they considered it advisable to do.

• 구강회복응용과학지
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• 제24권4호
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• pp.325-335
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• 2008

연성 이장재를 의치에 적용했을 때, 의치 변연부에서 나타나는 공극에 의한 문제점을 많이 경험하게 된다. 그래서 변연 공극을 최대한 줄일 수 있는 방법을 연구하여야 하고 특히 최종 과정인 마무리와 연마시의 변연 공극의 양상에 대한 평가가 이루어져야 한다. 본 연구에서는 실리콘 계열의 연성 이장재인 $Molloplast-B^{(R)}$를 적용하였을 때, 의치와 연성 의치 이장재의 접합부에서 나타나는 공극의 양을 측정하고 연마 방법, 연마 방향이 변연 공극에 미치는 영향에 대하여 알아보고자 하였다. 마무리 방법과 연마 방법, 방향에 따라 군 분류를 하였고, 시편의 일관성과 정확성을 위해 금속 틀을 방전 가공하여 제작하였고, 제조사의 지시에 따라 총 50개의 시편을 제작하였다. 공극의 양은 120배 확대의 입체 광학 현미경상에서 가장 큰 값을 가지는 부위를 측정하였고, 모든 측정치는 통계적 분석, 평가 하였다. 실험 결과, 각 분류에 따른 공극을 비교 했을 때, $Molloplast^{(R)}$-Cutter로 마무리 한 후 pumice와 tin oxide를 순행하여 연마를 한 경우가 가장 크게 나타났고, FSQ-cross cut bur를 이용하여 마무리만 한 것이 가장 적게 나타났다. 또한 연마를 할수록 공극의 양이 증가되는 양상을 나타내었다. 방향에 따라서는 통계적 유의성은 나타나지 않았으나 레진에서 연성 이장재 방향으로 시행하였을 때가 더 적은 값을 나타내는 경향을 보였다. 이상의 결과로 보아 삭제력이 우수한 버일수록 레진과 연성 이장재의 접합부에서 나타나는 공극이 커짐을 알 수 있었고, 또한 연마를 시행 할수록 공극의 양이 유의성 있는 차이를 나타내었다. 접합부에서의 공극을 줄일 수 있는 마무리와 연마 방법에 대한 더 많은 연구가 이루어져야 하고 부가적으로 최종 연마가 끝나고 공극을 막아 줄 수 있는 재료에 대한 연구가 필요한 것으로 사료된다.

• 한국프랜차이즈경영연구
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• 제1권1호
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• pp.1-17
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• 2010

프랜차이즈 가맹점의 계약 전 기대와 운영 후 지각된 성과에 대한 부정적 차이인식(gap)의 정도가 커지면 분쟁의 원인으로 발전할 수 있는데, 이는 근본적으로 가맹본부가 신규 가맹점 모집에 급급한 나머지 계약전 기대를 너무 높게 만들어 운영 후 지각된 성과와의 부정적 차이인식(gap)이 커지면서 발생하는 경우가 높다고 볼 수 있다. 따라서 본 연구에서는 가맹본부의 관계지향성에 대한 가맹점의 계약 전 기대와 운영 후 지각된 성과의 차이인식(gap)을 통해 가맹본부의 관계지향성에 대한 가맹점의 만족도를 간접적으로 측정하고, 관계지향성에 대한 차이인식(gap)이 프랜차이즈 업종별로 어떻게 다르게 나타나는지 알아보고자 한다. 본 연구의 실증분석 결과, 관계지향성에 대한 차이인식(gap) 평균이 모두 음(-)으로 나타난 것은 운영 후 지각된 성가가 계약 전 기대보다 낮다는 것을 의미하는 것으로, 가맹점 계약 전 기대관리의 필요성과 함께 프랜차이즈 업종별로 관계지향에 대한 차이인식(gap)이 다르게 나타났다는 것을 밝혔다는 데에서 그 의의를 찾을 수 있다. 이런 점들로 볼 때, 프랜차이즈는 가맹본부와 가맹점 간의 계약관계에 의해서 유지되는 시스템으로 지속적인 관계를 유지하기 위해서는 많은 노력과 함께 기대관리가 필요하다.

• Asian Journal for Public Opinion Research
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• 제5권3호
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• pp.175-191
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• 2018

This exploratory study considers the difference between personal and perceived societal values related to South Korean women's role in the home, workplace, and society using eight items asked on the Korean Academic Multimode Open Survey (KAMOS), May-July 2017. Factor analysis showed that these eight items could be grouped into two categories: women's role in her family and women's in the outside world. Of the 2,000 respondents, 54.1% personally agreed that "Both the husband and wife should contribute to their family income." People in their 30s felt the largest gap between their personal and societal values; women also felt a larger gap than men. Those who watched television more were generally more conservative than those who used the Internet more. People who felt a smaller gap between societal and personal values were more likely to feel proud to be a Korean citizen. People who believe that it is better not to marry felt a bigger gap between some societal and personal values on items relating to whether a wife should work, whether a woman's housework or paid job is more valuable, and whether women's job performance is equal to men's. People who believe that divorce is sometimes acceptable were also more likely to feel a bigger difference in two items: the item about job performance and an item about whether a married woman's social status is dependent on her husband's.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.463-469
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• 2017

PURPOSE. To evaluate the fit of a three-unit metal framework of fixed dental prostheses made by subtractive and additive manufacturing. MATERIALS AND METHODS. One master model of metal was fabricated. Twenty silicone impressions were made on the master die, working die of 10 poured with Type 4 stone, and working die of 10 made of scannable stone. Ten three-unit wax frameworks were fabricated by wax-up from Type IV working die. Stereolithography files of 10 three-unit frameworks were obtained using a model scanner and three-dimensional design software on a scannable working die. The three-unit wax framework was fabricated using subtractive manufacturing (SM) by applying the prepared stereolithography file, and the resin framework was fabricated by additive manufacturing (AM); both used metal alloy castings for metal frameworks. Marginal and internal gap were measured using silicone replica technique and digital microscope. Measurement data were analyzed by Kruskal-Wallis H test and Mann-Whitney U-test (${\alpha}=.05$). RESULTS. The lowest and highest gaps between premolar and molar margins were in the SM group and the AM group, respectively. There was a statistically significant difference in the marginal gap among the 3 groups (P<.001). In the marginal area where pontic was present, the largest gap was $149.39{\pm}42.30{\mu}m$ in the AM group, and the lowest gap was $24.40{\pm}11.92{\mu}m$ in the SM group. CONCLUSION. Three-unit metal frameworks made by subtractive manufacturing are clinically applicable. However, additive manufacturing requires more research to be applied clinically.

• Advances in nano research
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• 제3권1호
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• pp.13-27
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• 2015

Size dependent emission properties and the interband optical transition energies in group-III nitride based quantum dots are investigated taking into account the geometrical confinement. Exciton binding energy and the optical transition energy in $Ga_{0.9}In_{0.1}N$/GaN and $Al_{0.395}In_{0.605}N$/AlN quantum dots are studied. The largest intersubband transition energies of electron and heavy hole with the consideration of geometrical confinement are brought out. The interband optical transition energies in the quantum dots are studied. The exciton oscillator strength as a function of dot radius in the quantum dots is computed. The interband optical absorption coefficients in GaInN/GaN and AlInN/AlN quantum dots, for the constant radius, are investigated. The result shows that the largest intersubband energy of 41% (10%) enhancement has been observed when the size of the dot radius is reduced from $50{\AA}$ to $25{\AA}$ of $Ga_{0.9}In_{0.1}N$/GaN ($Al_{0.395}In_{0.605}N$/AlN) quantum dot.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.191-191
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• 2009

In this paper, we have confirmed the temperature of LED chip and McPCB with thermal simulation program which is CFDedign V10 for analysis the thermal flow of HP LED package. we have known that the heat from LED chip is transferred through heat slug to copper layer of McPCB. the temperature of LED chip shows 85.11 [$^{\circ}C$], which shows the temperature gap of 7.52 [$^{\circ}C$] against McPCB. the gap of temperature affect reliability of the wire bonding and die attachment. therefore, copper layer of heat slug on the McPCB should designed with the largest dimension.

• ETRI Journal
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• 제13권4호
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• pp.25-34
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• 1991

The stability and the electronic structure of $In_0.5$.$Ga_0.5$P-based superlattices are examined through self-consistent ab initio pseudopotential calculations. A chalcopyrite-like structure is found to be the lowest energy state over (001) and (111) monolayer superlattices (MLS). Our calculations indicate that all the ordered structures in bulk form are unstable against phase segregation into binary constituents at T = 0 while for epitaxial growth, the chalcopyrite phase is stabilized. The fundamental band gaps of the ordered structures are found to be direct and smaller than that of disordered alloys. The lowering of the band gap is explainable by band folding and pushing effects. We find the reduction of the band gap to be largest for the (111) MLS.