• 한국광학회지
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• 제4권4호
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• pp.447-451
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• 1993

용량이행형 방전회로를 이용하여 장펄스 XeCl 엑시머 레이저를 발진 시켰으며, 펄스폭은 150ns(FWHM)이었다. 펄스폭에 영향을 미치는 가스분압 및 capacitance의 비에 따른 펄스폭의 변화를 관측 하였으며, 이로부터 단펄스에서 장펄스로의 발진을 쉽게 얻을 수 있음을 알았다. 일정 가tm 혼합 비율([Xe]/[HCl]=15)의 상태에서 HCl과 Xe가스의 분압이 감소함에 따라 광 펄스폭의 최대 변화량은 125ns이었고, 일정 압력 하에서의 capacitance비(Cm/Cp) 변화에 늘어나는 광 펄스폭의 변화량은 60ns이었다.

• 대한소아치과학회지
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• 제23권2호
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• pp.365-374
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• 1996

The prupose of this study was to obtain standard measurements of the tooth size, Bolton ratio, width and length of dental arch and basal arch, overbite and overjet of the children who have normal dentition. The plaster cast of 97 children(47 boys and 50 girls) among the contestants in 1992, 1994, 1995 Healthy Dentition contest in Seoul were measured and following results were obtained. 1. Means and standard deviations of the mesio-distal maximum width of the permanent teeth, Bolton ratio, width and length of the dental arch and basal arch of the upper and lower dentition and overbite and overjet of the children were obtained. 2. Mesio-distal width of the teeth, width and length of the dental arch and basal arch of the upper and lower dentition of the boys were larger than those of the girls. 3. Bolton Overall ratio, Anterior ratio and overjet of the boys were larger than those of the girls and overbite of the boys were smaller than those of the girls, but no significant differences were noted between the boys and the girls(p>0.05). 4. In the comparision of the Healthy Dentition Contestants with Korean adults of Shur, all teeth of the Contestants were larger than those of Korean adults, especially upper and lower bicuspids(p<0.01). In the comparision of the Healthy Dentition Contestants with Caucasians, all teeth except upper and lower central incisor and upper first molar of the contestants were larger than those of Caucasians(p<0.05).

• 대한기계학회논문집
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• 제11권1호
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• pp.132-144
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• 1987

본 논문에서는 Isida의 이론해석 방법을 참고로 하여 유한한한 폭을 갖는 두 께가 변화하는 판재에서의 응력확대계수를 2차원 이론해석한 것이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.331-334
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• 2004

본 논문에서는 클록의 duty ratio가 변하였을 때, 그 클록의 duty ratio를 $50\%$의 duty ratio로 만들어 주는 Pulse Width Control Loop Circuit을 설계하였다. 기존의 논문에서는 duty ratio를 변화시키기 위해 각 duty ratio 마다 알맞은 제어 전압을 공급해하는 문제점이 있었다. 본 논문은 제어 전압이 변하지 않고 일정한 전압으로도 duty ratio를 변화시킬 수 있게 하여, 제어 전압 변화에 대한 문제점을 해결하였다. 설계, 시뮬레이션 결과 기존의 논문보다 간단해진 회로 구성으로 더욱 높은 주파수에서 동작하였다. 그리고 settling 시간도 기존의 논문의 l00ns 이상에서 5ns로 줄어듦을 확인할 수 있었다. 본 논문은 3.3V의 공급 전압에서 $0.35{\mu}m$ CMOS공정을 이용하여 설계하였고 동작 주파수는 500MHz-2GHz였고, settling 시간은 10n이하였다.

• 소성∙가공
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• 제16권7호
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• pp.502-508
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• 2007

Effect of the process parameters of the cogging process on the void crushing has been studied in order to identify the most effective factor. The process parameters considered in this study are die width ratio, reduction ratio and pre-cooling time before cogging process. Void crushing analysis with the selected process parameters was carried out using FE analysis. The results of FE analysis were evaluated by Taguchi method. It was found that the efficiency of void crushing increases with an increase in the values of all selected process parameters and the principal factor controlling the void crushing was identified as the reduction ratio.

• Steel and Composite Structures
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• 제36권2호
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• pp.187-196
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• 2020

Double skin composite wall system owns several structural merits in terms of high load-carrying capacity, large axial stiffness, and favorable ductility. A recently proposed form of truss connector was used to bond the steel plates to the concrete core to achieve good composite action. The structural behavior of rectangular high walls under compression and T-shaped high walls under eccentric compression has been investigated by the authors. Furthermore, the influences of the truss spacings, the wall width, and the faceplate thickness have been previously studied by the authors on short walls under uniform compression. This paper experimentally investigated the effect of width-to-thickness ratio on the compressive behavior of short walls. Compressive tests were conducted on three short specimens with different width-to-thickness ratios. Based on the test results, it is found that the composite wall shows high compressive resistance and good ductility. The walls fail by local buckling of steel plates and crushing of concrete core. It is also observed that width-to-thickness ratio has great influence on the compressive resistance, initial stiffness, and strain distribution across the section. Finally, the test results are compared with the predictions by modern codes.

• 한국산업보건학회지
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• 제3권2호
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• pp.204-212
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• 1993

This study was conducted to evaluate ventilation efficiency of 4-stage slot hood by variation of slot width, flow rate, hood size and baffle size. The slot velocity, control velocity and plenum velocity were related to slot width and the distance between source of contamination and hood. The results obtained from laboratory experiment for local exhaust ventilation systems were as follows ; 1. When slot widths were constant(equally changed) and the velocity was 6-10 m/s, the slot velocity from 1st slot to 4th slot gradually decreased. As the slot width-to-slot length ratio(WLR) decreased, the slot velocity of each stage increased. But if WLR value was less than 0.04, the slot velocity decreased. 2. When slot velocity exceeded 10 m/s with constant slot widths, the slot velocity of each stage was uniform. 3. When the slot velocity was uniform within 10 m/s and the first slot width was 14-20 mm, the slot width ratio between 1st slot and each of three other slots were 1, 1.25, 1.5 and 3.0, respectively. 4. The slot and plenum velocity were uniform when exhaust flow rate changed from 14 to $19m^3/min$ and there were no hood splitter vanes. 5. When the slot velocity at each stage was uniform, the control velocity at site 30 cm away from hood No.2 increased from 0.15-0.30 to 0.25-0.45 m/s and the control distance from 20 to 30 cm(about 1.5 times).

• 한국의류산업학회지
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• 제5권3호
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• pp.235-243
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• 2003

This study is to figure out where the current satisfaction with ready-to-wear clothes based on middle-aged women's body shapes is at and to propose basic considerations in its production for coming up with a better sizing system to maximize customer's satisfaction. The data obtained from measurement and questionnaire by 126 middle- aged (35-59) women which were located in Gwangju. Followings are summary of this research, 1)The satisfaction level with lower -wear is relatively lower-wear than that of upper-wear in most parts of body. 2) The results by way of putting score show three different groups. Group 1 has characteristics of front body silhouette in the small ratio of shoulder width/bust width, shoulder width/waist width and big ratio of shoulder width/hip width. And Group 3 has characteristics of front silhouette, small ratio of hip girth/thigh girth. Group 2 has a standard shape. 3) The satisfaction level with lower-wear based on middle-aged women's body shapes shows slight difference. In this category, Group 2 has higher satisfaction level than that of Group 1, while Group 1 has better shape than Group 3. 4) The items of clothes which should be considered current less satisfaction on their size and pattern are skirt and pants. In the meantime, specific body parts for the same criteria are hip girth, thigh girth. And the 43.7% of middle-aged women who responded to this study requires improvement on the fit of lower-wear.

• 한국강구조학회 논문집
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• 제17권5호통권78호
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• pp.561-568
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• 2005

본 논문의 목적은 트러스 인장웨브재의 형상이 정방형 각형강관인 기존 연구(강관웨브형)와 고장력 강봉을 인장웨브재로 사용하기 위해 연결플레이트를 가지는(강봉웨브형) 냉간성형 각형강관 갭 K형 접합부의 거동 비교를 통하여 고장력 강봉 사용의 적정성을 알아보기 위한 것이다. 주관폭두께비가 33.3으로 동일한 강관웨브형 실험체 4개와 강봉웨브형 실험체 8개의 최대내력, 파괴모드, 초기강성, 연성율 등을 비교하였다. 비교 결과, 접합부의 내력은 강관웨브형에서는 압축지관의 선행파괴로 결정되었으며, 강봉웨브형에서는 인장측의 선행파괴로 결정되었다. 무차원화 내력은 동일 폭비에서 강관웨브형이 높게 나타났으며, 폭비 증가에 따른 내력증가현상도 강관웨브형에서 뚜렷하게 나타나고, 강봉웨브형은 일정한 경향이 나타나지 않은 반면에 인장과 압축폭비로 나누어 살펴보면 인장폭비 증가에 따라서는 선형적인 증가현상이 나타남을 알았다. 파괴모드는 강관웨브형의 경우에는 압축지관의 미소 국부좌굴과 인장웨브와 주관 접합면의 소성파괴가 나타났고, 강봉웨브형의 경우는 주관플랜지면 소성변형 후 연결플레이트 용접부위의 파단이 나타났다. 따라서, 강봉웨브형에서 연결 플레이트를 갖는 갭K형 접합부의 경우에는 강관웨브형에 비해 주관의 폭두께비를 낮게 할 필요가 있으며, 폭비도 인장지관과 압축지관과의 관계를 고려하여 결정하여야 할 것으로 판단된다.

• The Journal of Advanced Prosthodontics
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• 제4권1호
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• pp.13-17
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• 2012

PURPOSE. We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. MATERIALS AND METHODS. A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe $Photoshop^{(R)}$ 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. RESULTS. The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. CONCLUSION. After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards.