• Steel and Composite Structures
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• 제48권3호
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• pp.263-273
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• 2023

This paper investigates dynamic characteristics of a graphene nanoplatelets reinforced composite (GNPRC) sandwich doubly curved shell based on the first-order shear deformation theory (FSDT) and Hamilton's principle. The sandwich doubly curved shell is fabricated from a core made of honeycomb materials sandwiched by composite GNPs reinforced face-sheets. Effective materials properties of composite face-sheets are assumed to vary based on Halpin-Tsai micromechanical models and rule of mixture. Furthermore, the material properties of honeycomb core are estimated using Gibson's formula. The fundamental frequencies of the shell are computed with changes of main geometrical and material properties such as amount and distribution type of graphene nanoplatelets, side length ratio, thickness to length ratio of and side length ratio of honeycomb. The Navier's technique is presented to obtain responses. Accuracy and trueness of the present model and analytical solution is confirmed through comparison of the results with available results in literature. It is concluded that an increase in thickness to length ratio yields a softer core with lower natural frequencies. Furthermore, increase in height to length ratio leads to significant decrease in natural frequencies.

• 한국의류산업학회지
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• 제22권6호
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• pp.826-833
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• 2020

When it is necessary to wear masks for long periods, such as during the current COVID-19 pandemic, the essential function of masks to prevent contamination (or transmission to others) as well as comfortableness are important. For this study, we used three-dimensional (3D) facial measurements of adult women to compile basic face shape data for designing comfortable and effective masks. This study analyzed the 3D facial data of 127 subjects in their 20s to 30s of the 6th Size Korea. Factor analysis of the survey data produced seven factors that formed the composition of adult female faces. These factors combined to produce three facial types: square (long face and a large lower middle face), oval (smallest central and lower body in the middle), and triangle (short face with a small central and lower large nose). These types reflect that the facial types of adult women show the differences in the nose angle, nose length, bitragion-subnasal arc, bitragion-menton arc. Therefore, properly fitting masks for fine dust particle filtration require 3D customization of a mask's breathing apparatus to fit differently shaped central and lower face parts that interfere with mask fit.

• 대한치과교정학회지
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• 제37권3호
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• pp.192-203
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• 2007

본 연구는 비폐쇄를 보이는 III급 부정교합아동에서, 기도 공간의 형태와 안모 골격 형태 사이의 상관관계를 평가하였다. III급 부정교합을 보이며, 비폐쇄 소견을 보여 이비인후과로 의뢰된 환아 100명의 초진 측모 두부 규격 방사선 사진에서 상 인두기도 공간(upper PAS), 하 인두기도 공간(lower PAS), 편도의 크기, 구개-혀 공간을 측정하여 기도 공간 형태를 분석하였으며, 통상적인 계측점을 사용하여 안면 골격 분석을 시행하여 기도 공간 형태 계측항목과 안면 골격분성 항목간의 상관관계를 연구하여 다음과 같은 결과를 얻었다. Upper PAS는 ramal height, SNA, SNB, PFH, FHR, facial plane angle 항목과 양의 상관관계를 보였으며, saddle angle, articular angle, gonial angle의 sum, SN-GoGn, Y-axis to SN, FMA 항목과 음의 상관관계를 보였다. Lower PAS는 genial angle, FMA와 양의 상관관계를 보였으며, articular angle, facial depth, PFH, FHR와 음의 상관관계를 보였다. 편도의 크기는 PCBL, ramal height, Mn. body length, Mn. body length to ACBL, facial depth, facial length, PFH, AFH와 양의 상관관계를 보였다. 구개-혀 공간은 saddle angle, articular angle, genial angle의 합, facial length, AFH, FMA, LFH와 양의 상관관계를 보였으며, IMPA, overbite와 음의 상관관계를 보였다.

• 대한치과교정학회지
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• 제21권1호
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• pp.185-195
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• 1991

This study was undertaken to grope the correlation of the maximal bite force and tooth-craniofacial structure. The maximal bite force of 76 adult male, aged 18-28 (mean aged: $23.4{\pm}2.2$) years, was estimated and cephalometric headplates were measured, tabulated and statistically analyzed. The results were as follows. 1. 59.61kg of bite force in first molar, 45.38kg in premolar and 17.10kg in central incisor were arranged. 2. The bite force was negatively correlated to genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and positively correlated to posterior height of face, length of mandibular body, length of ramus, facial depth in craniofacial structure. 3. The group with strong bite force showed small genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and long posterior height of face, length of mandibular body, length of ramus, facial depth. So they manifested the tendency to brachycephalic pattern, on the other hand, the group with weak bite force manifested the tendency to dolichocephalic pattern. 4. There is no correlationships between bite force and mesial inclination of premolar axis in this subject. 5. It is considered bite force have an effect upon craniofacial pattern, especially upon the lower face.

• 치과방사선
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• 제25권2호
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• pp.459-470
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• 1995

The purpose of this study was to determine whether any difference existed in craniofacial morphology between cleft children and normal subjects. Thirty three measurements of the various regions of cranium and face were obtained from lateral cephalometric radiograms in 40 cleft children(27 males, 13 females) and 40 normal subjects(23 males, 17 females) in our dental hospital from Jan. 1988 to Dec. 1995.The measurements were compared with those in control subjects who had no history of craniofacial abnormalities. The obtained results were as follows: 1. In the cranium, the cleft children had singificantly shorter posterior cranial base length(S-Ba) and total antero-posterior cranial base length(N-Ba) (P<0.05). 2. In the upper face, the cleft children had significantly shorter upper anterior facial height(N-ANS) and upper posterior facial height(Ptm'-SNL) (P<0.05). 3. In the lower face, the cleft children had significantly shorter antero-posterior mandibular length(Pog-Ar) and antero-posterior mandibular body length(Pog-Go) (P<0.05). 4. In the facial profile, the cleft children had significantly shorter total facial height(N-Me} and posterior facial height(S-Go) (P<0.05).

• 대한치과교정학회지
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• 제18권1호
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• pp.235-252
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• 1988

The quadrilateral analysis is a proportional analysis which evaluates the skeletal configuration of lower face on the relations between both jaws in the horizontal as we]1 as vortical dimensions. This study was undertaken to analyse the harmony and disharmony of quadrilateral patterns in normal occlusion and malocclusion. The present study was carried out on lateral cephalograms of 530 Korean children; the subjects consisted of 135 normal occlusions (63 male and 72 female), 105 Class II division 1 malocclusions (52 male and 53 female), 109 Class III malocclusions (50 male and 59 female), 91 hypodivergent facial types (44 male and 47 female) and 90 hyperdivergent facial types (45 male and 45 female). The following conclusions were reached: 1. Means and standard deviation in each group and sex were obtained from normal occlusion and malocclusion. 2. Quadrilateral mean diagram in normal occlusion was constructed for male and female, respectively. 3. In normal occlusion, 1:1 ratio exists between the maxillary base length (A' to Ptm') and mandibular base length (B' to J'), but lower facial height is targer than above. 4. Difference is effective to estimate the degrees of Class II and Class III malocclusion, and lower facial height (LFH) and sagittal angle is effective to recognize the hypodivergent and hyperdivergent facial type. 5. Quadrilateral analysis is able to visualize the anteroposterior and vertical dysplasia of lower face, and it is helpful to recognize certain problems in malocclusion.

• 대한치과교정학회지
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• 제26권5호
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• pp.547-556
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• 1996

본 연구는 성장기의 골격성 III급 부정교합 환자에서 face mask를 이용하여 상악골을 전방 견인하였을 때, 골격 및 치아관계와 연조직 측모의 변화를 관찰하고 face mask사용전후의 경조직과 연조직 변화의 유의성을 검정하여 상악골 열성장을 보이는 골격성 III급 부정교합 환자의 진단과 치료계획 수립에 도움을 주고자 하였다. 서울대학교병원 치과진료부 교정과에 내원하여 상악골 열성장에 의한 골격성 III급 부정교합으로 진단받고 face mask를 사용하여 양호한 치료결과를 보인 환자 15명을 대상으로 face mask사용전후 두부 방사선 계측사진을 촬영하고 face mask 사용전 계측치와 face mask사용후의 계측치를 분석하여 다음과 같은 결과를 얻었다. 1. SNA와 상악골의 실제 길이인 Co-A가 통계적으로 유의한 수준으로 증가하여(p<0.001), 상악골은 face mask에 의한 치료후 상당량 전방위치 되었다. 이는 face mask의 orthopedic effect에 의한 것이다. 2. 상, 하악골의 실제길이를 나타내는 Co-A, Co-Gn이 face mask 사용후 모두 유의성있게 증가하였다(p<0.01). 3. 하악골의 위치는 상당량 후하방 회전되었다. FMA(p<0.001), SN-GoGn(p<0.01), Y-axis(p<0.01) 등이 face mask 사용후 유의성있는 증가를 보였다. 4. 상악전치, 하악전치의 face mask사용후 치축의 경사도는 유의성있는 차이를 보이지 않았다. 5. 연조직에 대한 변화에서 상순의 위치가 전방으로 변화하여 정상적인 측모의 평균치에 가깝게 변한 것이 인정되었다(p<0.01).

• 사상체질의학회지
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• 제10권2호
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• pp.221-270
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• 1998

Objective This research is a study about constitutional diagnosis through the external appearances as a basic principle, and it is for finding shape differences of the ear, eye, nose, mouth according to the Sasang constitution Method We have collected 209 cases of patients of the Sasang Constitutional Department, including employees of the Kyung-Hee Medical Center and took pictures of the frontal view, lateral view, oblique view of face and measured heights, deapth, breadths of ear, eye, nose, mouth with 'The Measurement of R. Martin'. We analyzed shape differences of the face according to the Sasang constitution with certain results Results We got the morphologic characteristics of ear, eye, nose and mouth according to the Sasang constitution as Table 3. -Table 10. Conclusion : 1. The morphologic characteristics of Ear according to the Sasang constitution (1) Morphologic ear length, Physiognomic ear length, Ear lobule length is longer in Taeumin than Soeumin. (2) Physiognomic ear breadth is wider in Taeumin than Soeumin. (3) Physiognomic ear length, lobule length ratio is higher in Taeumin than Soyangin. 2. The morphologic characteristics of Eye according to the Sasang constitution. (1) Inner Palpebral fissure width, 5th Palpebral fissure length, Bizygomatic breadth-Outercanthal distance is the longest in Taeumin (2) Palpebral fissure inclination is widest in Soeumin. (3) Palpebral fissure length is longer in Taeumin than Soeumin. (4) Pupillary diameter ratio is the lowest in Taeumin (5) Palpebral fissure length, width ratio is higher in Soeumin than Taeumin. (6)zygomatic breadth, Bizygomatic breadth-Outercanthal distance ratio is the higher in Taeumin than Soeumin. 3. The morphologic characteristics of Nose according to the Sasang constitution. (1) Nasion depth is deepest in Soyangin. (2) Nasion to pupillary depth is deeper Soyangin than Taeumin. (3) Nasal tip depth, Nostril to Nasalalar depth is deeper Soyangin than Taeumin. (4) Subnasale to Nasalalar depth is the shallowest in Taeumin (5) Nasalalar height is lowest in Soeumin. (6) Nasalalar to Nostril distance is deeper Taeumin than Soeumin. (7) Nasal tip depth, Nasal depth ratio is the highest in Taeumin (8) Nasal depth Nasalalar heightratio is lowest in Soeumin. (9) Midfaceheight, Nasal tip depth ratio is higher Soyangin than Taeumin. 4. The morphologic characteristics of mouth according to the Sasang constitution. (1) Lower mid lip height, Lower philtrum height, Lower quarter lip height, Total middle lip height, Total philtrum height, Total quarter lip height is the shottest in Soyangin. (2) Upper mid lip height, Upper philtrum height is longer in Taeumin than Soyangin (3) Lip inclination is higher in Soeumin than Soyangin. (4) Intercheilion breadth, total height ratio is lowest in Soyangin. (5) Total lip height, Upper philtrum height ratio is higher in Soyangin than Soeumin. (6) Lower lip height Lower quarter lip height ratio is higher in Soyangin than Taeumin. (8) Total lip area is wider in Taeumin than Soyangin.

• 사상체질의학회지
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• 제20권3호
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• pp.58-69
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• 2008

1. Objective This research looks into the facial characteristics of Sasang constitution. 2. Methods It assigns and measures the length of nine areas of the face using a picture, and calculates the proportions and gives statistical data of these items. It also references the proportion of the items using the contents of "Sanghakjinjeon" ("相學眞傳") Ten face-types as a basis, divides the face into seven types, looks into the similarities between constitutions, and also compares it to clinically and frequently used constitutional facial characteristics. 3. Results and Conclusion After comparing the analytical items between Taeumins, Soyangins, and Soeumins, Soeumins had an oval face due to the fact that the length and width that their lower faces took up was small compared to the entire face. After dividing the facial characteristics of the test subjects using 十字相, there were significantly more Taeumins in Dong(同)_face-type, and Soeumins in Won(圓)_face-type. There weren't any significant group that Soyangins showed up in. After comparing these facial characteristics with that of previous facial characteristics found in books and used clinically, we were able to find corresponding items.

• 한국컴퓨터정보학회논문지
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• 제27권10호
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• pp.185-193
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• 2022

본 연구는 성인 여성의 얼굴 유형에 적합한 마스크 패턴 개발을 위하여 시판되고 있는 다회용 마스크 패턴을 비교·분석하고자 하였다. 이를 통해 마스크 패턴 개발 및 생산업체에 필요한 자료를 제공하고자 하였다. 시판 다회용 마스크 패턴의 치수 및 형태를 비교한 결과, 성인용으로 제작된 L사이즈 마스크임에도 불구하고 치수에 있어서 큰 차이를 나타냈다. 가상착의에 대한 외관평가 결과 정면의 앞중심선의 수직, 마스크의 윗부분 감쌈과 여유, 코높이, 마스크 아랫부분의 감쌈과 여유에서 디자인별로 유의미한 차이가 있었다. 측면도 얼굴 옆부분의 감쌈, 옆부분의 여유, 끈 간격과 길이에서 유의미한 차이를 나타냈다. 외관평가 결과, 마스크4가 가장 좋은 평가를 받았다. 마스크 패턴의 형태는 코 아랫부분에 크게 다트가 있어 얼굴의 입체적인 형태를 커버할 수 있도록 되어 있으나 마스크에 따라 곡선의 정도와 각도에 차이를 나타냈다. 마스크 상부와 마스크 하부, 볼 부분은 밀착되지만, 코와 입 부분에는 여유가 있는 마스크 패턴의 평가가 높았다. 마스크 패턴은 얼굴형 및 치수에 대한 분석을 통해 마스크 상부길이와 하부길이, 코 높이에 따른 마스크 다트량의 설정이 이루어져야 할 것으로 생각된다.