• 한국멀티미디어학회논문지
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• 제8권5호
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• pp.633-640
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• 2005

본 논문에서는 피부객 정보와 투영 기법에 기반한 적응적 얼굴 영역 추출 알고리즘을 제안하였다. 제안한 기법은 피부색 정보에 기반한 얼굴 후보 영역 추출 단계와 투영 단계로 구성된다 얼굴 후보 영역 추출 단계에서는 먼저 입력 영상에서 피부색 구간 범위로 피부색 후보 화소들을 추출하였다. 그리고 피부색 후보 화소로 추정된 화소 수와 전체 화소수의 비를 계산하고, 이에 따라 적응적인 피부색 구간 문턱 값을 설정하여 얼굴 후보 영역을 추출하였다. 투영 단계에서는 얼굴 폭 추정을 위해 추출된 얼굴 후보 영역을 수직 투영을 하였다. 그리고 추정된 얼굴의 폭 정보는 얼굴의 길이 추정을 위한 수평 투영 시에 이용하였다. 다양한 영상들에 대한 실험 결과 제안한 알고리즘은 기존의 얼굴 영역 추출 알고리즘보다 정확한 얼굴 영역 추출 결과를 보였다.

• 한국의류학회지
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• 제33권6호
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• pp.938-948
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• 2009

본 연구는 2003년에서 2004년에 실시된 제 5차 한국인 인체치수 조사사업을 통해 확보된 측정사진 중 성인여성 20, 30, 40, 50대 각 150명, 총 600명의 정면과 측면 얼굴사진을 대상으로 얼굴의 연령별 특성을 파악하는데 필요하다고 판단되는 62개의 측정항목과 보다 세부적인 얼굴형태의 분석에 활용될 수 있는 21개의 지수 및 계산항목 총 83개 항목을 본 연구자가 선정한 후 Size Kroea 사업 중 얼굴의 측정 프로그램으로 사용되었던 "Venus face2D"를 이용하여 2차원 간접 측정하였다. 간접 측정기간은 2006년 3월 1일부터 6월 30일까지였다. 연구의 결과는 다음과 같다. 성인여성의 주요 측정항목에 대한 평균 측정치는 얼굴길이 196mm, 상안 62.3mm, 중안 68.9mm, 하안 66.5mm이었고, 이마너비는 125.1mm, 눈살수평너비는 141.2mm, 옆광대점너비 150.8mm 턱아래점너비 124.4mm였다. 이를 바탕으로 우리나라 성인여성 얼굴의 세부항목에 대한 연령집단별 차이를 분석하였으며, 전체 성인여성의 평균 얼굴형과 더불어 각 연령집단별 평균 얼굴형을 제시하였다. 본 연구는 정량화된 수치와 비율을 이용하여 우리나라 성인여성 및 각 연령별 평균 얼굴형을 제시하고, 연령별 얼굴특성을 분석하였다는데 연구의 의의가 있다.

• 대한치과교정학회지
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• 제20권2호
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• pp.293-304
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• 1990

The purpose of this study was to describe the morphologic differences between long-face adults and normal-face adults on the lateral and P-A cephalograms. Long-face and normal-face subifects were selected clinically, and then each of them was taken the lateral cephalogram. According to SN-MP angle and ATFH on the lateral cephalogram, long-face group and normal-face group were classified. 2 long-face adults and 18 normal-face adults were collected, and each of them was taken the P-A cephalogram. The results were as follows: 1. The morphologic differences between long-face adults and normal-face adults were closely related to mandibular morphology. 2. Long-face adults, compared with normal-face adults, demonstrated significant increase in ALFH, and significant decrease in ramus height. 3. Long-face adults, compared with normal-face adults, demonstrated significant increase in AUDH and, ALDH, especially in ALDH. 4. On the P-A cephalogram, no measures of transverse dimension demonstrated significant differences between two groups. 5. On the P-A cephalogram, facial height/facial width ratio was significantly larger than normal in the long-face adults, and in the normal-face adults, facial height/facial width ratio was approximately 90%. 6. In the correlation analysis of SN-MP angle and ATFH with all the other variables, the correlation coefficients of SN-MP angle and PTFH/ATFH that of ATFH and ALFH on the lateral cephalogram demonstrated the highest value, and on the P-A cephalogram, SN-MP angle and Cg-GA-Me (Lt.), ATFH and lower facial height demonstrated the highest value of correlation coefficients.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.605-608
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• 2007

The discharge characteristics of the face-to-face sustain electrode structure employing auxiliary address pulse are investigated under a sustain driving frequency of 20 kHz and various auxiliary address pulse widths (500 ns, $1{\mu}s$, $2\;{\mu}s$) in the 6-in. test panel (42-in. Full HD grade) with a pressure of 450 Torr and a 4 % Xe-content. The luminance and the luminous efficiency at the auxiliary address pulse width of 500 ns are improved more than these of $1\;{\mu}s$ and $2\;{\mu}s$. At the auxiliary address pulse width of 500 ns, the luminous efficiency shows about 0.96 lm/W at the auxiliary pulse of 90 V and the sustain voltage of 260 V.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권2호
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• pp.204-210
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• 2000

The mandibular contour determines the shape of the lower part of the face and thus influences the appearance of the face. A patient with a large, squarish, or broad face who desires a small, round, or slender face can undergo mandibular contouring surgery to reduce the width of the lower face. The successful correction of a prominent mandibular angle by conventional angle ostectomy has been reported. But, in the majority of patients with a widened facial appearance, both the mandibular angle and part of the mandibular body anterior to it are protuberant laterally, so both must be resected. The purpose of this study is to introduce a new method of performing mandibular contouring surgery, more effectively and easily, and to reduce postoperative complication and evaluate its results. We treated 6 patients who has prominent mandibular angle using multiple step osteotomy with angle-splitting ostectomy. The advantages of this new method are as following. (1) easily performable (2) effective mandibular contouring surgery by reducing the width of lower face (3) producing a natural relief of the mandibular angle (4) low risk of soft tissue damage and complications (5) shortening of the operation time. etc.

• 한국산업보건학회지
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• 제33권2호
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• pp.145-155
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• 2023

Objectives: A fit test panel is needed to identify the fit performance of a respirator and its face seal. This is a criterion for selecting subjects that can represent the facial characteristics of users. Although anthropometry data has been developed for people in United States and China it is not yet present in Korea. This study aimed to develop a Korean fit test panel and test headform. Methods: For the 7th and 8th waves of the Size Korea anthropometry data, facial measurements of 11,429 people aged 15 to 69 years were used for analysis. PCA and bivariate panel were classified using the ISO16976-2:2022(E) anthropometrics analysis method. Based on this result, a static headform was developemed and a fit test chamber was constructed. Results: Of the 11,429 Korean people used for principal component analysis, 11,300 were included in the ellipse, marking an acceptance rate of 98.87% on PCA panel. The face types were classified into five types. Among them, a large, medium, and small static headform were printed using a 3D printer. In addition, 10,985 people (96.12%) were included in the bivariate panel based on face length and face width. The y-axis (face length) boundary was 97.87 to 134.59 mm, and the x-axis (face width) boundary was 120.75 to 158.23 mm. Conclusions: Compared to the ISO analysis, the Korean principal component was narrower in the width item (PC1) and longer in the length item (PC2). For the future, it is necessary to conduct a fit test using the developed headform and chamber device to confirm the usefulness of this Korean test panel. Therefore, this study is considered valuable as basic research for Korean test panels.

• 농업과학연구
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• 제43권4호
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• pp.650-655
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• 2016

Gears are components of transmission which transmit the power of an engine to a machine and offer numerous speed ratios, a compact structure, and high efficiency of power transmission. Gear train design in the automotive industry uses simulation software. However, PTO (Power Take-Off) gear design for agricultural applications uses the empirical method because of the wide range of load fluctuations in agricultural fields. The PTO is an important part of agricultural tractors which transmits the power to various tractor implements. Therefore, a simulation was essential to the optimal design of the PTO. When the PTO gear is optimally designed, there are many advantages such as low cost, reduced size, and light weight. In this study, we conducted the bending and contact safety factor simulation for the PTO gear of an agricultural tractor. The bending and contact safety factors were calculated on ISO 6336 : 2006 by decreasing the face widths of the PTO pinion and wheel gear from 18 mm at an interval of 1 mm. The safety factor of the PTO gear decreased as the face width decreased. The contact safety factors of the pinion and wheel gear were 1.45 and 1.53, respectively, when the face width was 18 mm. The simulation results showed that the face width of the PTO gear should be greater than 9 mm to maintain the bending and contact safety factors higher than 1. It would be possible to reduce the weight of the PTO gear for different uses and working conditions. This study suggests that the possibility of designing an optimal PTO gear decreases as its face width decreases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권6호
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• pp.407-420
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• 2003

Purpose : The purpose of this study was to analyse the facial changes and factors contributing to then after bilateral sagittal split ramus osteotomy of mandibular prognathism. Materials and Methods : Forty patients with Class III dental and skeletal malocclusion who were treated with bilateral sagittal split ramus osteotomy were reviewed. Frontal and lateral cephalometric radiographs were taken preoperatively, immediate postoperatively and more than six months postoperatively in each patient. After tracing the cephalometric radiographs, various parameters were measured. Results : 1. Gonial angle at postoperative two days was decreased about $10.4^{\circ}$ than preoperatively and gonial angle at postoperative six months was increased about $6.8^{\circ}$ than postoperative two days. So, gonial angle at postoperative six months was decreased about $3.6^{\circ}$ than preoperative gonial angle. 2. Facial height postoperative two days was decreased about 0.8mm than preoperatively and facial height at postoperative six months was decreased about 0.7mm than postoperative two days. So, facial height at postoperative six months was decreased about 1.5mm than preoperative facial height. 3. Mandibular width postoperative two days was decreased about 1.0mm than preoperatively and mandibular width at postoperative six months was increased about 1.8mm than postoperative two days. So, mandibular width at postoperative six months was decreased about 2.8mm than preoperative mandibular width. 4. Amount of set back and mandibular plane angle were not influencing on relapse degree. Conclusion : It is thought that bilateral sagittal split ramus osteotomy in mandibular prognathic patients is effective to improve long face and steep gonial angle. More prudent operation and careful postoperative management is required to maintain stable face postoperatively. Further research for soft tissue changes and factors which are related with relapse is needed.

• 한국정밀공학회지
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• 제3권4호
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• pp.30-42
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• 1986

On the analysis of cutting mechanics in orthogonal cutting, each cutting force component can be predicted. By adding the flank face wear term to the prediction equation for cutting force components, complete equations are obtained. Using these equations, it is shown that cutting force components are increased linearly as flank face wear land is developed, in theory and experiment. By making non-dimensional term ie. Fv/Fc, the width of variation of output signal Fv/Fc is greately decreased compared with each cutting force component as cutting condition is varied. Among these conditions, the variation of chip width in the range of more than 1mm and that of cutting velocity have little effect on the output signal Fv/Fc, that of Flank face werr land can be detected without difficulty.

• 소성∙가공
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• 제17권3호
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• pp.203-209
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• 2008

In this paper, experimental investigation has been performed to analyze the forming process of toothed or serrated sheets, which is used as strap engaging surface of the seal to secure together overlapping portions of steel or plastic strapping ligature. Serration formed on the strap engaging surface of the seal prevent from relative slipping between overlapping ligatures after closing the seal. The geometry of tooth on the strap engaging surface is directly related to the quality of securing overlapping ligatures together. Inclined indentation followed by scratching operation has been proposed and applied to the experiments. Punch entry and face angles are selected as process variables to see the influence of these variables on the tooth geometry. Five different punch entry angles have been applied to experiments and three different punch face angles have been selected for each case of punch entry angle. Clay is selected as model material for experiments. Experimental results are summarized in terms of tooth height, tooth width, and aspect ratio such as tooth height to width ratio, respectively.