• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.237-244
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• 2024

We studied the effects on their academic achievement of chemistry II and advanced chemistry subjects of science high school students according to the type of class (face-to-face and non-face-to-face). The subjects of this study were 195 first-year students of G Science High School located in Gyeongnam. The average scores of Chemistry II and Advanced Chemistry in non-face-to-face classes in 2020 and face-to-face classes in 2021 were compared and analyzed. As a result of comparing and analyzing the academic achievement according to the class type, students' grades in Chemistry II and Advanced Chemistry were higher in non-face-to-face classes. In the comparison of academic achievement by level according to class type, Chemistry II showed higher average grades in non-face-to-face classes as the lower level were, and in advanced chemistry, the higher the upper grades in non-face-to-face classes. In addition, in terms of the effect of changes in class form on the upper and lower 10% levels of academic achievement of Chemistry II, the upper 10% showed high grades in face-to-face classes and the lower 10% in non-face-to-face classes. On the other hand, in advanced chemistry, the average grade of non-face-to-face classes was higher than that of face-to-face classes in the top 10%, and the average grade of face-to-face classes was higher than that of non-face-to-face classes in the bottom 10%. Through these results, it was found that in the teaching-learning of science high school students, instructors need to design and treat teaching-learning appropriate to the level of academic achievement.

• Research in Mathematical Education
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• v.2 no.1
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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.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.1
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• pp.3-11
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• 2003

Face stability of a tunnel is a main concern during tunnel excavation. However, there has been only a few studies on this problem while a lot of researches on the support systems have been carried out. In addition, when tunneling is performed below the groundwater level, the groundwater flows into the tunnel so that the seepage forces generated on the tunnel face might give rise to a serious potential for the face instability. In this study, the face stability was evaluated by simultaneously considering two factors: one is the effective stress calculated by upper bound theorem; the other is the seepage forces acting on the tunnel face obtained by numerical analysis under the condition of steady-state groundwater flow. Tunneling in difficult geological conditions often requires auxiliary techniques to guarantee safe tunnel excavations and/or to prevent damage to structures and services around the tunnel. The steel pipe-reinforced multistep grouting has been recently applied to tunnel sites in Korea. Face stability of a tunnel with the steel pipe-reinforced multistep grouting was also analyzed in this study.

• Geomechanics and Engineering
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• v.25 no.3
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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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• v.11 no.4
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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.

• Journal of Biomedical Engineering Research
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• v.44 no.4
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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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.2 no.1
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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.

• The Research Journal of the Costume Culture
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• v.8 no.1
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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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• v.15 no.4
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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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• v.37 no.4
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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.