• 문화기술의 융합
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• 제10권2호
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• pp.237-244
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• 2024

우리는 수업 형태 (대면, 비대면)에 따라 과학고 학생들의 화학II 및 고급화학 과목의 학업성취도에 미치는 영향을 연구하였다. 연구 대상은 경남 소재 G 과학고등학교 1학년 학생 195명을 대상으로 하였다. 2020년의 비대면 수업과 2021년의 대면 수업에 의한 화학II 및 고급화학 평균 점수를 비교·분석하였다. 수업 형태에 따른 학업성취도를 비교·분석한 결과, 비대면 수업에서 학생들의 화학II 및 고급화학 성적이 높게 나타났다. 수업 형태에 따른 수준별 학업성취도 비교에서, 화학II는 하위권일수록 비대면 수업의 평균 성적이 높게 나타났고, 고급화학은 상위권일수록 비대면 수업의 평균 성적이 높게 나타났다. 또한, 수업 형태의 변화가 화학II의 학업성취도 상위 및 하위 10% 수준에 미치는 영향에서, 상위 10%는 대면 수업에서 높은 성적을 보였고, 하위 10%는 비대면 수업에서 높게 나타났다. 반면, 고급화학에서 상위 10%는 비대면 수업의 평균 성적이 대면 수업의 평균 성적보다 높았고, 하위 10% 수준은 대면 수업의 평균 성적이 비대면 수업의 평균 성적보다 더 높게 나타났다. 이러한 결과를 통해, 과학고 학생들의 교수-학습에서, 교수자는 학업성취 수준에 적합한 교수-학습의 설계 및 수업 처치가 필요한 것으로 나타났다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제2권1호
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• pp.21-39
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• 1998

The article examines four activities whereby the human face of geometry may be promoted in mathematical teaching at the upper secondary level. The activities deal with the historical, epistemological, structural and applicative issues of geometric knowledge.

• 한국터널지하공간학회 논문집
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• 제5권1호
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• pp.3-11
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• 2003

터널 시공 시 막장의 안정은 주요 관심사이다. 그러나, 터널 지보재에 비해 상대적으로 터널 막장의 안정성 문제는 그리 많은 연구가 이루어지지 않은 실정이다. 또한 지하수위 하에서 터널 시공 시 터널 내로 지하수 흐름에 의해 발생된 침투수력은 막장의 안정성에 큰 영향을 미칠 수 있다. 본 논문에서는 두 가지 요소를 고려하여 터널 막장의 안정성을 평가하였다. 하나는 극한이론 중 상한치 이론으로 산출된 유효응력이며, 다른 하나는 정상류 흐름조건에서 수치해석으로부터 산출된 침투수력이다. 열악한 지반조건에서 터널 시공 시 터널의 안정과 인접 구조물의 손상을 방지하기 위해 보조공법이 적용된다. 강관 다단 그라우팅 공법은 근래 국내에서 적용되고 있는 보조공법 중의 하나이다. 본 논문에서는 강관 다단 그라우팅으로 보강된 터널의 막장 안정성도 함께 평가되었다.

• Geomechanics and Engineering
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• 제25권3호
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• pp.233-243
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• 2021

Rib spalling is a major issue affecting the safety of steeply inclined coal seam. And the failure coal face and support system can be affected with each other to generate a vicious cycle along with inducing large-scale collapse of surrounding rock in steeply inclined coal seam. In order to analyze failure mechanism and propose the corresponding prominent control measures of steeply inclined coal working face, mechanical model based on coal face-support-roof system and mechanical model of coal face failure was established to reveal the disaster mechanism of rib spalling and the sensitive analysis of related factors was performed. Furthermore, taking 3402 working face of Chen-man-zhuang coal mine as engineering background, numerical model by using FLAC3D was built to illustrate the propagation of displacement and stress fields in steeply inclined coal seam and verify the theory analysis as mentioned in this study. The results show that the coal face slide body in steeply inclined working face can be observed as the failure height of upper layer smaller than that of lower layer exhibiting with an irregular quadrilateral pyramid shape. Moreover, the cracks were originated from the upper layer of sliding body and gradually developed to the lower layer causing the final rib spalling. The influence factors on the stability of coal face can be ranked as overlying strata pressure (P) > mechanical parameters of coal body (e.g., cohesion (c), internal fraction angle (φ)) > support strength (F) > the support force of protecting piece (F') > the false angle of working face (Θ). Moreover, the corresponding control measures to maintain the stability of the coal face in the steeply inclined working face were proposed.

• Geomechanics and Engineering
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• 제11권4호
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• pp.471-492
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• 2016

Underground tunnelling is one of the sustainable construction methods which can facilitate the increasing passenger transportation in the urban areas and benefit the community in the long term. Tunnelling in various ground conditions requires careful consideration of the stability factor. This paper investigates three dimensional stability of a shallow circular tunnel in a layered soil. Upper bound theorem of limit analysis was utilised to solve the tunnel face stability problem. A three dimensional kinematic admissible failure mechanism was improved to model a layered soil and limiting assumptions of the previous studies were resolved. The study includes calculation of the minimum support pressure acting on the face of the excavation in closed-face excavations. The effects of the characteristics of the layers on the minimum support pressure were examined. It was found that the ratio of the thickness of cover layers particularly when a weak layer is overlying a stronger layer, has the most significant influence on the minimum tunnel support pressure. Comparisons have been made with the results of the numerical modelling using FLAC3D software. Results of the current study were in a remarkable agreement with those of numerical modelling.

• 대한의용생체공학회:의공학회지
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• 제44권4호
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• pp.242-254
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• 2023

Although upper respiratory tract infections (URTIs) are common diseases, there have been no studies of their relationship with the indices obtained from tongue image analyses. The purpose of this study was to identify a tongue index through an analysis of tongue images (TIs) showing significant changes before and after treatment in patients with URTIs. A computerized tongue image acquisition system was developed to acquire TIs from subjects in the same environment. An image was taken from each of 39 URTI patients and 39 healthy controls. For the patients, images were acquired before and after treatment to identify changes. The tongue area was classified into a tongue body and a tongue coating, and the coating ratio between the two areas, the average value of the colour of each area, and teeth marks were calculated. No significant difference was observed in age or sex between the URTI patients and control participants. Heart rates were slightly different. The analysis of TIs showed that the luminance of the tongue coating and the coating area ratio were decreased, while the reddish value of the tongue body at the centre area increased as the treatment progressed. Tongue coating and body in URTIs had different colour and shape from those in the normal. It is expected that this result will contribute not only to the objectification of traditional Chinese medicine but also to diagnostic methods that do not involve face-to-face physician visit during the pandemic.

• 치과방사선
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• 제2권1호
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• pp.23-27
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• 1972

A roentgenographic cephalometric study was made on the soft and hard tissue profile of Korean adults. The subject consisted of 52 males and 54 females from 17 to 22 years of age and with normal occlusion and acceptable profile. Twenty one landmarks were plotted and two oriented lines named SnH line and SnV line were drawn on the tracings of all cephalograms. The means and the standard deviations from the subjects were calculated in each measuring category and the means were compared with those of male and femal samples. The results were obtained as follow: 1. In depth and height, individual variations and sex differences of the lower facial profile were larger than the upper face. 2. The sex differences of upper facial profile were larger in height than depth. 3. The individual variations and sex differences of the top of nose were the smallest in all measuring points. 4. The thickness of the soft tissue of upper face and upper lip in male sample were larger than those of female, but the same matter were not found in mental region.

• 복식문화연구
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• 제8권1호
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• pp.133-144
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• 2000

The purpose of this study was to classify women's face types by visual distinction and to analyze the measurement of face types. A survey was conducted by subjects of 167 women's college students in Kwangju City and Chonnam area. Data were analyzed by Frequencies, Mean, one way ANOVA and Ducan's Multiple Range Test. The major results were as followed ; ·Women's face types were classified by 7 types and there were oblong shape(28.3%), egg shape(25.7%), round shape(23.9%), square shape(12.4%), inverted triangle shape(5.3%), diamond shape(3.5%), triangle shape(0.8%) in the subjects. ·From the measurements of the women's face, index of face length to face breadth was 1.38, it means that the index was different from the other refferences. And the lower face length was longer than the upper and the middle face lengths. ·Differences From those measurements like forehead breadth, face length/bizigion breath(p〈.001), bizigion breadth, bignathion slopper, stature(p〈.01) and trichion breadth, tragion-menton length(p〈.05) were significant in the classified face types.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권4호
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• pp.329-337
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• 1993

Improvement of orthognathic surgical techniques make it possible to design esthetic surgical correction for total esthetic face. In order to find the esthetic line which guide esthetic surgical correction in patients of orthognathic surgery, cephalometric soft tissue analysis of esthetic faces were performed. In esthetic Korean young adults, 25 males and 25 females who were within 1 S.D. of E-line, ANB, P/A facial height ratio, were analyzed in natural position keeping their face eye level. 1. Sn position is constant in males and females. The Sn-N'-N' Vertical plane angle is $5.3^{\circ}$ in both sexes. Sn is positioned in front of 5 mm in female 7 mm in male from the N' vertical plane. 2. The Sn-Ls line make constant angle to horizontal plane with $72.5^{\circ}$ in both sexes, which is called "upper esthetic line". The Ls-Pg' line makes constant angle to $72.4^{\circ}$ (range $72.2^{\circ}$ in female to $72.6^{\circ}$ in male), which is called "lower esthetic line". 3. When inter-esthetic line angle (the Sn-Ls line to Ls-Pg' line) has $144.9^{\circ}$, lower third face has esthetic upper and lower lip. 4. In treatment planning, Sn is first corrected in proper position, and then upper and lower esthetic line are established with the angle of 144.9. The maxilla is moved to tangent Ls to the upper esthetic line, and mandible is moved to tangent Li and Pg' to the lower esthetic line, according to the "y"-shaped esthetic lines, then lower third face showes esthetics.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.351-360
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• 2010

Purpose: As the influence of mass media increases, the general standard of attractiveness or beauty of a face also changes. The primary purpose of the study is to find out the factors of the attractive and beautiful face recognized by public. Methods: We picked out standard model photography and operated with Adobe$^{(R)}$ Photoshop$^{(R)}$ and Monariza$^{(R)}$ virtual plastic surgery program. The contour of face, eye, nose, forehead, zygoma, chin and proportion of upper, middle, lower face were changed. The interview survey was conducted through structured standard photo for 310 respondents. That was utilized in the final analysis. Multiple regression analysis was executed by SPSS 12.0. It was used to deal with statistical data and all the other necessary analysis. Results: According to general characteristics of the respondents, many differences were found in preferred face and facial aesthetic subunits. The younger generation preferred the lozenge and inverted triangle shape contour. The respondents over 40 of age preferred the egg shape contour. In chin and zygoma contour, the respondents at the age of 20 preferred distinctly small chin and relatively small lower face. On the other hand, the respondents over 40 of age preferred the wide zygoma relatively. In the proportion of upper, middle, lower face, 51.0% of respondents answered 1 : 1 : 1. If they want to have an aesthetic operation, they preferred protruding forehead. Also they preferred the small chin and V-shaped chin in frontal view. Conclusion: Many respondents preferred to have a plastic surgery for the better facial subunit. The statistical evidence from this study suggests that the harmony and balance of facial aesthetic subunits make attractive and beautiful face.