• Imaging Science in Dentistry
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• 제31권4호
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• pp.205-207
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• 2001

Purpose : The aim of present study is to estimate the relationship among reference lines used for taking the extraoral radiography and panoramic radiography. Materials and Methods: Lateral cephalographs of 40 adults, aged 22 to 30 years were taken. Angles between reference lines (Frankfort line, canthomeatal line, infraorbitomeatal line, and occlusal plane) were measured. Results: Angles between Frankfort line and canthomeatal line, Frankfort line and infraorbitomeatal line, Frankfort line and occlusal plane, canthomeatal line and infraorbitomeatal line, canthomeatal line and occlusal plane, and infraorbitomeatal line and occlusal plane were 16.1° (±2.2), 5.8° (±2.4), 8.7° (±3.5), 10.3° (±1.3), 24.8° (±4.0), and 14.5° (±4.4),respectively. Conclusion: Angle between frankfort and canthomeatal line is very different with commonly known angle. Frankfort horizontal reference lines used for panoramic radiography need an exact definition and more accurate standard is needed for the taking of panoramic radiograph.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.195-199
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• 2008

We present an approach to detect real plane for line base recognition and pose estimation Given 3D line segments, we set up reference plane for each line pair and measure the normal distance from the end point to the reference plane. And then, normal distances are measured between remains of line endpoints and reference plane to decide whether these lines are coplanar with respect to the reference plane. After we conduct this coplanarity test, we initiate visibility test using z-buffer value to prune out ambiguous planes from reference planes. We applied this algorithm to real images, and the results are found useful for evidence fusion and probabilistic verification to assist the line based recognition as well as 3D pose estimation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권3호
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• pp.266-273
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• 2005

Purpose: To assess the relationship between soft tissue reference line and hard tissue reference line using the standardized photographs and the posteroanterior cephalometric radiographs(P-A)in facial asymmetric patients and to compare the differences of angular measurement between normal group and asymmetry group. Methods: Normal group consisted of 44 persons with normal occlusion and normal facial morphology. Asymmetry group consisted of 90 patients with facial asymmetry. Standardized facial photographs and P-A were taken in all subjects. The horizontal reference lines were bipupillary line in photographs and latero-orbitale line in P-A respectively. The vertical reference line were the line from the midpoint of horizontal reference line perpendicularly. Angular measurement of otobasion canting, lip canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in photographs. And angular measurement of mastoid canting, mandibular canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in P-A. Results: 1. The variables of photographs and P-A were significantly related in the asymmetry group. 2. Significant differences between all variables except for PT2 and PA2 were shown in the asymmetry group and between PT1 and PA1, PT3 and PA3 in the normal group respectively. 3. Comparison measurement scores of angular difference between control group and experimental group concerning each variable showed significant difference except for PA1. Conclusions: Soft tissue components may not compensate for underlying skeletal imbalance in nose deviation and chin deviation. The horizontal reference lines in photographs were significant related with the P-A, but angular variables between the two studies show significant differences. Therefore, we do not recommend use photography in the assessment the facial asymmetry as complemented in the P-A.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.153-157
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• 2002

Purpose : This study was performed to determine the proper reference line for taking axial computed tomograms from which the good cross-sectional views can be reformatted by multiplanar reconstruction. Methods : Three dry mandibles with implanted gutta percha cones in the extracted socket were scanned axially according to 6 reference lines of 2 mandibular positions with computed tomogram Hitachi W550. The accuracy of measurements of the lengths of implanted gutta perch a cones in the each cross-sectional view reformatted from axial computed tomogram by multiplanar reconstruction was evaluated. Results: The difference between the measurements and the real length of implant was smallest in the bucco-lingual views reformatted from the axial views scanned according to the reference line of group V-a. The smaller the angle difference between reference line and occlusal line was, the smaller the difference between the measurements in the bucco-lingual views reformatted from axial views and the real length of implant. The majority of measured widths of implants in the bucco-lingually reformatted views were larger than the actual values. Conclusions : When the mandible is inclined within the limitation of gantry angle and scanned with the reference line coincident with occlusal plane, the bucco-lingual view can be reformatted without deformation of images from the axially scanned images.

• Imaging Science in Dentistry
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• 제35권1호
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• pp.25-31
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• 2005

Purpose : To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Materials and Methods : Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occlusion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. Results : With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. Conclusion : It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

• Smart Structures and Systems
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• 제17권5호
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• pp.725-742
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• 2016

This paper is focused on stiffness ratio effect and a new method to specify the best pattern of piezoelectric patches placement around a hole in a plate under tension to reduce the stress concentration factor. To investigate the stiffness ratio effect, some different values greater and less than unity are considered. Then a python code is developed by using particle swarm optimization algorithm to specify the best locations of piezoelectric actuators around the hole for each stiffness ratio. The results show that, there is a line called "reference line" for each plate with a hole under tension, which can guide the location of actuator patches in plate to have the maximum stress concentration reduction. The reference line also specifies that actuators should be located horizontally or vertically. This reference line is located at an angle of about 65 degrees from the stress line in plate. Finally two experimental tests for two different locations of the patches with various voltages are carried out for validation of the results.

• 한국전자파학회논문지
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• 제11권4호
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• pp.649-656
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• 2000

본 논문에서는 두꺼운 외부도체를 가진 손실이 있는 동축선로의 해석적인 특성임피선스 표현식 및 근사식을 제안했다. 그리고 제안된 근사식을 동축선로의 동작 주파수대역에서 사용 가능하다는 것을 3.5mm reference air line에 대해 보였다.

• 전력전자학회논문지
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• 제8권5호
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• pp.435-441
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• 2003

순시전압강하보상기 (DVR)는 순시전압강하 및 상승을 보상하기 위한 가장 효과적이고 경제적인 수단으로 알려져 있다. 본 논문은 계통의 전압이 사고에 의해서 심하게 왜곡되는 경우에서도 계통과 동기된 정현적인 기준파를 생성하는 방법을 제시한다. 제안된 기준파발생기 (RWG)는 사고로 왜곡된 전압으로부터 원래의 정현적인 파형을 추출하고 정상 성분만의 전압을 합성하여 DVR의 제어에 사용하도록 한다. 전윈 전압의 사고 순간에도 RWG는 과도적인 문제가 없는 안정된 정현 파형을 출력한다.

• Journal of electromagnetic engineering and science
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• 제4권3호
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• pp.97-101
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• 2004

Complex permittivities of reference liquids were measured by a liquid holder of slotted coaxial line with a movable probe at mobile communication frequencies. The validity of the liquid measurement system was checked by experimental tests with the reference liquids proposed in IEEE Std. 1528-200X or IEC 106/61/CDV.

• Communications for Statistical Applications and Methods
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• 제9권2호
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• pp.401-410
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• 2002

This paper revisits parallel-line bioassay problem, from a Bayesian point of view using noninformative priors such as Jeffreys' prior, reference priors, and probability matching priors. After finding the orthogonal transformation, the class of first order and second order probability matching priors are derived. Jeffreys' prior and reference priors are derived also. Numerical examples are given to show the effectiveness of noninformative priors.