• Title/Summary/Keyword: Triangle points

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Evaluation of Bonwill triangle using cone beam computerized tomography in Korean (콘빔형 전산화단층영상을 이용한 한국인의 본윌 삼각에 대한 평가)

  • Kong, Hyun-Jun;Oh, Sang-Chun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.2
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    • pp.97-103
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    • 2018
  • Purpose: The aim of this study was to evaluate the Bonwill triangle of Korean using the cone beam computerized tomography (Cone-beam CT). Materials and Methods: 120 Koreans (60 males and 60 females) who visited Daejeon Dental College Hospital of Wonkwang University and who underwent the Cone-beam CT were selected. The Cone-beam CT images were analysed with Invivo 5.1 (Anatomage, San Jose, USA). After reorientation of axis, the intercondylar distance was measured by clicking both middle points of condyle. And the condyle-incisor distance was measured by clicking the middle point of condyle and contact point of the mandibular central incisor's incisal edge. The collected data were analysed using the SPSS Version 23.0 (IBM Inc., Armonk, USA) and statistical significance was verified by gender using independent t-test. Results: The mean intercondylar distance of Korean was 105.9 mm, and the male (108.3 mm) was statistically significantly larger than the female (103.4 mm). The mean condyle-incisor distance of Korean was 105.2 mm, and the male (108.1 mm) was statistically significantly larger than the female (102.3 mm). Conclusion: The mean intercondylar distance of Korean in this study was 105.9 mm that was smaller than well-known 110 mm of Caucasian and the male was statistically significantly larger than the female. Within the limitations of this study, it would be necessary to use the articulator which can adjust the intercondylar distance according to the individual for prosthodontic treatment of Korean.

Study on the Optimum Positions of Theodolite Station for Control Surveying (기준점측량(基準點測量)을 위한 데오돌라이트 관측점(觀測點)의 최적위치(最適位置)에 관한 연구(研究))

  • Yeu, Bock Mo;Lee, Jae Ki;Park, Hong Gi
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.4 no.4
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    • pp.95-103
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    • 1984
  • This paper is a study on improving the accuracy of control points by suggesting angular requirements which make geometric conditions to be optimum. For this purpose, a equation, by which the accuracy of control point coordinates measured in an arbitrary station can be estimated, is derived. This equation is integrated and average standard error of the coordinates is computed, so that the optimum location of observatory station is determined. In the case of triangulation, a regular triangle has been generally considered as the best geometric condition, but because the precision of each side is different, the $52.77^{\circ}$ isosceles triangle is founded to be the best one. Also in trigonometric leveling, the geometric condition is founded to be optimum when the base angle of a isosceles triangle is $45^{\circ}$. In control surveying for close-range photogrammetry the optimum relation between base length($B_0$) and object distance($D_0$) can be founded to be as follow; $D_0=0.357587-0.357967B_0+0.308555B_0{^2}$.

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A STUDY ON THE FACIAL ESTHETIC PREFERENCES AMONG KOREAN YOUTHS: ASSESSMENT OF PROFILE PREFERENCES (한국 젊은이의 안면미 선호경향에 관한 연구 : 얼굴의 측모평가를 중심으로)

  • Song, Sejin;Choi, Ik-chan
    • The korean journal of orthodontics
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    • v.22 no.4 s.39
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    • pp.881-920
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    • 1992
  • This study was designed to assess profile preferences among Korean youths in the year 1992. Facial esthetics was evaluated by means of silhouette profiles, eliminating the influence of a number of aspects that may affect judgment when normal lateral photographs are used. The main points of preference to be clarified here are as follows. First, on facial convexity, Second, on nasion depth, Third, on mentolabial sulcus depth, Fourth, on the position of upper and lower lips, Fifth, on facial type according to Angle's classification of malocclusion, Sixth, on Song's tangents. The 54 subjects printed in questionnaire as black and white silhouettes were selected from 300 tracings from cephalometric radiographs of people whose age ranging from 11 to 20 years. Photographs of six female subjects were retouched by computer graphic software and printed in color and black/white photographs which were used for adaptation of eyes of participants in selecting profiles in silhouette. They constitute 2 questions. The 54 subjects were grouped as 22 questions, each of them composed of 6 subjects, according to the aspects to be clarified. Twenty four questions in total were asked to assess profile preferences. For the assessment, the profile line, the facial esthetic triangle, Song's tangents, and Angle's classification of malocclusion were introduced. The profile line is composed of 11 component points which are Trichion, Glabella, Nasion, Pronasale, Subnasale, Labrale superius, Stomion, Labrale inferius, Supramentale, Pogonion, and Gnathion. The facial esthetic triangle is composed of 3 tangents: A-tangent which is the tangent of dorsum of nose, B-tangent which is the line passing through Sn and Ls, and C-tangent which is drawn on the turning point of the curve which lies between mentolabial sulcus (Sm) and pogonion (Pg). Angle's classification has 3 types of malocclusion which are Class I, Class II, and Class III. Class II malocclusion is subdivided into Division 1 and Division 2. The participants of the survey were composed of 861 college students (448 male students, 413 female students) whose majors grouped as Fine Arts. Liberal Arts, and Natural Sciences, and whose mean age 21.8 years. The statistics program SPSS/PC + of SPSS Inc. was used to analyze answers of participants. Crosstabulation, Chi-square test, and Kendall test were done. The conclusions are as follows: First, Korean youths have a tendency to prefer the slightly convex face to the flat or concave face. Second, they prefer a moderately deep nasion. Third, they prefer a moderately deep mentolabial sulcus. Fourth, they prefer the position of lips which are near to Ricketts' E-line. The position of the upper lip which is slightly posterior to E-line is preferred. The upper lip which lies too far anterior or posterior to the lower lip is not perferred. Fifth, they prefer most, according to Angle's Classification of Malocclusion, Class I facial profile which has a slight inclination to Class II division 2. The order of preference is Class I, Class II division 2, Class III, and Class II division 1. Sixth, they prefer the type 2 and 3 of Song's tangents. The facial profile within which A-and B-tangent meet is preferred. The facial profile which has Cotangent that .meets with A-tangent slightly posterior to the crossing point of A-and B-tangent or that parallels with B-tangent is preferred.

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An Experimental study on the human's physiological in Smart Textile Materials by Using Medical Infrared Thermo graphic Imaging (적외선 체열 영상 진단법을 이용한 스마트 섬유소재와 휴대폰 통화량에 따른 인체 생리반응 연구)

  • Lee Tae-il;Lee Su-jeong;Lee Kyung-mi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.7 s.144
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    • pp.918-925
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    • 2005
  • The following are the results from the infrared body temperature image test to verify the changes in facial temperature according to call duration with a cellular phone. As for the body temperatures, it appears to be the mean value at the upper central point of phone's battery among 7 different points that are measured, and to be the highest at srernocleido-mastoid and scapular trapezius muscle triangle zone$(34.25^{\circ}C\; and\;34.05^{\circ}C\;each)$. The changes of body temperature according to the time duration shows that the body temperature rises according to the length of phone use because of the heat emitted from the battery. As for the temperature changes according to blocking materials, the one without processing appears to be higher in the mean temperature compared to the others that are processed, NSS(Nano Silver Silk) and NSG(Nano Silver Silk Gold) appear to be the lowest in the temperature to show the best blocking property. As for the temperature changes according to measuring points, it appears to be the highest at P4, P5 with all materials, and one with NSG to be the lowest at Pl, P2, P3, and one with NSS to be the lowest at P3, P4, P5, P6, which is due to the thermal conduction of Au and Ag. And the mean temperature at each point appears to be different according to the materials. Therefore, the study conducted with human participants requires a proper particle size of it which would not penetrate cellular tissues and a proper binder and binding treatment for it, to prevent the physical fatigues and the potential diseases. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

Understanding the Construction of Chang-ui in the Middle Chosun Dynasty -Through the Process of Reconstructing Chang-ui Excavated from General Parks Tomb- (조선중기 창의구성의 이해 -전 박장군묘 청색무명겹창의의 재현을 통하여-)

  • 장인우
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.3
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    • pp.548-559
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    • 2001
  • This study is to understand Chang-ui construction of the middle Chosun Dynasty through the reconstruction of the blue Chang-ui which was excavated from General Parks tomb. The followings are the results of this study. There are 4 styles in excavated Chang-ui of middle Chosun Dynasty: Two styles seem to belong to the early 17th Century and the other, the late 17th century. The former is classified into 2 styles by the gender of the wearer, the latter is also classified into 2 styles by etiquette of clothing. We can assume that Chang-ui excavated from General Parks tomb was the womans clothing in early 17th century. This Chang-ui(II) differs from other Chang-ui(I) at two points. One is the construction of the trapezoid and triangle gussets on the side seam of clothing. The other is the construction of the narrow width of clothing(23cm). We have found that these two gussets could improve the active aspect of clothing and save materials. It is identified that the green tone was faded from the blue color of Chang-ui according to the calculation of the L*a*b.

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Noise Reduction Technique by Three-Points Ensemble Averaging in Uroflowmetry (삼점 신호 평균기법에 의한 요속신호의 잡음 축소 기법)

  • Choi, Seong-Su;Lee, In-Kwang;Lee, Sang-Bong;Park, Jun-Oh;Lee, Su-Ok;Cha, Eun-Jong;Kim, Kyung-Ah
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.8
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    • pp.1638-1643
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    • 2009
  • Uroflowmetry is a convenient clinical test to screen the benign prostatic hyperplasia(BPH) common in the aged men. A load cell is located beneath the urine container to measure the weight of urine. However, it is sensitive to the impact applied on the bottom of the container by the urine stream, which could be a noise source lowering the reliability of the system. With this aim, our study proposed a noise reduction technique by computing ensemble average of the weighted signals that were acquired from three-load cells forming a regular triangle beneath the urine container. Simulated urination experiment was performed with three different collection methods, all of which demonstrated significant noise reduction by ensemble averaging. Furthermore, the best results can be obtained without any special urine collection devices. Thus, our novel method can be usefully applied to uroflowmetry for enhancing measurement in terms of accuracy and reliability.

Attitude and Position Estimation of a Helmet Using Stereo Vision (스테레오 영상을 이용한 헬멧의 자세 및 위치 추정)

  • Shin, Ok-Shik;Heo, Se-Jong;Park, Chan-Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.7
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    • pp.693-701
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    • 2010
  • In this paper, it is proposed that an attitude and position estimation algorithm based on a stereo camera system for a helmet tracker. Stereo camera system consists of two CCD camera, a helmet, infrared LEDs and a frame grabber. Fifteen infrared LEDs are feature points which are used to determine the attitude and position of the helmet. These features are arranged in triangle pattern with different distance on the helmet. Vision-based the attitude and position algorithm consists of feature segmentation, projective reconstruction, model indexing and attitude estimation. In this paper, the attitude estimation algorithm using UQ (Unit Quaternion) is proposed. The UQ guarantee that the rotation matrix is a unitary matrix. The performance of presented algorithm is verified by simulation and experiment.

Hydrodynamic performance of a pump-turbine model in the "S" characteristic region by CFD analysis

  • Singh, Patrick Mark;Chen, Chengcheng;Choi, Young-Do
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.10
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    • pp.1017-1022
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    • 2015
  • Specific hydrodynamic characteristic of pump-turbine during the start and load rejection process of generating mode causes anomalous increase of water pressure, along with large machine vibration, called "S" characteristic. The aim of this study is to understand and explain the hydrodynamic performance of pump-turbine at "S" characteristic region by using a model of pump-turbine system. The operation in the condition of runway and low discharge in a typical "S" characteristic curve may become unstable and complex flow appears at the passage of guide vane and impeller. Therefore, velocity and pressure distribution are investigated to give an all-sided explanation of the formation and phenomenon of this characteristic, with the assistance of velocity triangle analysis at the impeller inlet. From this study, the internal flow and pressure fluctuation at the normal, runway and low discharge points are explored, giving a deep description of hydrodynamic characteristic when the pump-turbine system operates with "S" characteristic.

Study on the magnetic flux distribution of transformer by the use of finite element method (유한요소법에 의한 변압기의 자속분포 해석에 관한 연구)

  • 임달호;현동석;이철직
    • 전기의세계
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    • v.29 no.4
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    • pp.247-255
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    • 1980
  • In this study, an application of Finite Element Method which, in principle, based on variational calculus has been presented for the two-dimensional analysis of magnetic flux distribution in the shell type core of single phase transformer. The necessary stationarity condition of energy functional and boundary conditions were determined under the assumptions that the electromagnetic field considered is stationary and that the effect of eddy current is negligible. In the process of application the domain of magnetic field was divided into triangle subsectional elements and then the matrix equations were constructed for the respective triangular element and for those of all after the manipulation of minimization process to the vector potential of magnetic field at the each vertex of the element. Furthermore the numerical computation for the equations was guided by the Gaussian Elimination Methods. As the results obtained, it is found that the aspect of magnetic flux distribution inside the core as well as the leakage flux profile at the vicinity of the inner leg of the core is not much different from the well-known distribution profile of magnetic flux, however, the procedure shows to possess the merit of the uniquely deterministic nature for the flux distribution at the desired points.

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The Role of Northeast Asian Cities in a Global Urban Network

  • Rozman, Gilbert
    • Journal of the Korean Regional Science Association
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    • v.15 no.2
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    • pp.5-19
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    • 1999
  • This paper identifies five factors that limited urban network formation in Northeast Asia over the past half millennium, questions the extent to which they are being overcome in the 1990s, and sketches a network of cities that could boost regionalism. It briefly traces the historical evolution of these factors, including comparisons with European integration, while focusing primarily on the policies of the 1990s that have affected their continuing role. First is the factor of closed national markets with weak regional integration. Second is the preeminence of administrative means of integration over commercial ones. Third is the character of localism, shackled by overcentralization and weak cross-border linkages. Fourth is the limited nature of internationalism, dominated by state catch-up policies with one-sided global involvement. Fifth is a lack of regional consciousness. Just as national urban integration was essential for regional networks to form, without regional integration it is difficult to contemplate Northeast Asian cities taking their rightful place in a global urban network. After noting the failures of the 1990s, the paper points to the potential role as dragon's heads for sub-regional urban networks of potential front-line cities: Tumen, Sapporo, Irkutsk, and what I call the Amur triangle. Also of interest are how the capitals of Beijing, Moscow, Seoul, and Tokyo will adjust to a transformed urban network. After all, their current skepticism must be overcome with a program that links the benefits on all sides in order to build trust in regionalism. This requires internationalism and symbols of a balanced approach to each country's needs.

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