• Title/Summary/Keyword: 중심 변위

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Sagittal Reference Plane for Soft Tissue Analysis in Facial Asymmetry Patients (안면 비대칭 환자에서의 연조직분석을 위한 시상기준선)

  • Chung, Dong-Hwa
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.1
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    • pp.63-71
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    • 2011
  • Major type of facial asymmetry results from facial deformity and needs surgical correction. To diagnose facial asymmetry and set a treatment plane for patients, setting a sagittal reference plane is crucial. The purpose of this study is comparison of measurements of sagittal soft tissue reference point to three different sagittal planes. The subjects are 25 of asymmetry patients (M:15, F:10) and 19 of normal people. There are differences in point Gnathion and Stomion. Most of measurement of sagittal reference points showed within 1 mm difference from sagittal reference plane. Deviation of point Pronasale in Sa1 plane revealed significant difference among 3 reference planes. The deviation of Gnathion was proportional to the deviation of Stomion in all 3 reference planes.

초광대역전송선형 FM 변별기에 관한 연구

  • 이충웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.2 no.1
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    • pp.10-13
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    • 1965
  • 본논문은 단종된 전송선과 개방된 전송선 및 2개의 결합저항기로 구성된 초광대역전송선형 FM변별기의 동적인 해석(dynamic analysis)을 취급하였다. 변별기의 출력파형의 Harmonic Distortion과 입력신호의 최대허용주파수변위와의 제관계를 Fourier transfrom으로 상세하게 해석하였다. 결합저항계수r(Fig 1 참조)는 변별기의 감도와 입력신호의 전주파수변위에 걸쳐 입력 Impedance가 일정하다는 견지에서 일로 놓아야 된다는 것이 판명되었다. 이론상으로는 100%의 주파수변위를 가진 FM신호라도 본변별기로 불과 2.6% Harmonic distortion으로 검파할 수 있으며 또한 검파시에 변별기의 입력 Impedance는 전종선의 특성 Impedance Z0로 일정하게 유지된다. 이론적인 결과를 뒷받침하기 위하여 실험결과를 첨부하였다. 본실험에서는 변별기의 특성곡선이 중심주파수 85.5Mc를 중심으로 40%의 주파수변위에 대하여 Linear하며, 또한 이때의 변별기의 입력 Impedance의 변화율은 이상치 Z0의 ±14% 이내이다.

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The Analysis of the Pulsed Rectilinear Movement by the Angular Acceleration (각 가속도에 의한 선형 펄스 운동의 해석)

  • 정병태
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.353-355
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    • 2002
  • 지금까지 회전운동을 선형운동으로 만들기 위해 많은 연구가 되어 실제장치의 특허는 1980년대부터 볼 수 있으나 분명한 이론적 근거가 없었다. 회전운동을 선형운동으로 만들기 위한 방법 중 한 가지를 소개한다. 회전중심의 팔에 관성질량이 달려 있으면 회전중심으로 회전 중 각 가속도를 강제로 제어발생시 작용 반작용에 의해서 관성질량에 순간 질량중심이 발생한다. 그 결과 계 전체의 질량중심에 순간회전 변위가 발생한다. 계의 질량중심의 회전변위를 한 방향이 되도록 각가속도를 적절히 제어하면 선형 선형적인 펄스 운동을 얻을 수 있다. 기존 실제 장치들의 운동특성을 참조하여 회전중심 과 순간질량 중심 및 계의 질량중심 관계의 모델을 세우고 수식 및 이론을 정의하여 해석한다.

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Design of the microwave phase shifter using p-i-n diodes (p-I-n 다이오드를 이용한 마이크로파 위상변위기 설계)

  • 최재연;이상설
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.2
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    • pp.3-10
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    • 1995
  • In this paper, the phase shifter using the p-i-n diode is designed and analyze. The large phase shift can be achieved by the swithched-line and the hybrid branch line phase shifter, however the small phase shift can be achieved by the loaded-line phase shifter, according to the bias state of the p-i-n niode. The results of the experiment agree with those of computer simulation at the center frequency.

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GPS를 이용한 대류권 수증기의 3차원 분포도 결정을 위한 습윤지면 추정 정확성 향상

  • 박관동;하지현;박종욱
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.44-44
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    • 2004
  • GPS를 이용하여 대기 수증기의 3차원 분포도를 구하기 위하여, 관측소와 GPS 위성 간 시선방향으로의 수증기에 의한 GPS 신호지연 정도를 결정할 필요가 있다. 이 때 정확성 향상을 위하여 반드시 고려해야하는 위상중심변화(phase center variations)와 조석하중에 의한 지각변위(ocean loading displacements) 등 수직방향 좌표 결정 오차를 유발하는 요인들을 소개한다. 타 연구를 통해 위상중심변화는 크게는 l0cm 이상의 오차를, 그리고 조석하중에 의한 지각변위는 한반도의 경우 최대 3-4cm 정도의 오차를 보임을 알았지만, 이들 오차가 시선방향 습윤지연 결정에 미치는 영향은 규명되지 않았다. (중략)

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A Study of the Optimal Displacement Analysis Algorithm for Retaining Wall Displacement Measurement System Based on 2D LiDAR Sensor (2D LiDAR 센서 기반 흙막이 벽체 변위 계측 시스템의 최적 변위 분석 알고리즘 연구)

  • Kim, Jun-Sang;Lee, Gil-yong;Yoou, Geon hee;Kim, Young Suk
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.2
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    • pp.70-78
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    • 2023
  • Inclinometer has several problems of 1)difficulty installing inclinometer casing, 2) measuring 2D local lateral displacement of retaining wall, 3) measurement by manpower. To solve such problems, a 2D LiDAR sensor-based retaining wall displacement measurement system was developed in previous studies. The purpose of this study is to select a displacement analysis algorithm to be applied in the retaining wall displacement measurement system. As a result of the displacement analysis algorithm selection, the M3C2 (Multiple Model to Model Cloud Comparison) algorithm with a displacement estimation error of 2mm was selected as the displacement analysis algorithm. If the M3C2 algorithm is applied in the system and the reliability of the displacement analysis result is secured through several field experiments. Convenient management of the displacement for the retaining wall is possible in comparison with the current measurement management.

A study on the analysis and identification of error motion in planetary gear system (유성치차장치의 회전오차 해석과 그 진단에 관한 연구)

  • 박천경;박동삼
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.1
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    • pp.43-53
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    • 1990
  • The manufacturing errors such as pitch error and run-out error in planetary gear system bring about the irregular displacement of the center of each gear, which cause the torqe variation, vibration and noise. In this study, the relation between manufacturing errors and error motions of the center of gear was analyzed, and it can be applied to identyfy the errors of gears by investigating the measured locus of the center of each gear. Also, another identification method of power spectrum estimation using FFT algorithm was introduced, which analyze the frequency of the measured error motions. The results show that the error of each gear had a corresponding unique frequency, therefore, this method proved to be more effective.

A Study on Behavior of the Earth Retaining Structure by Field Measurement and Numerical Analysis (현장계측과 수치해석에 의한 흙막이구조물의 거동 비교분석)

  • Wo, Jongtae
    • Journal of the Society of Disaster Information
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    • v.13 no.3
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    • pp.286-295
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    • 2017
  • In this study, it is compared various coefficients of subgrade reaction for application of numerical analysis based on measured data by using various theories and empirical formula. The ratio of the maximum and minimum value is 6.80 at the top of wall but it is 1.06 at the maximum displacement point depends on change of calculated coefficient of subgrade reaction. The data of displacement were generally similar considering an increment of a coefficient of subgrade reaction. And the results of comparison of the displacement at the maximum displacement point by numerical analysis and measured data show similar displacement shape.

Derivation of Relation between Variation of Gradients of Antenna Tower of GNSS Permanent Observatories Depending on Diurnal Variation of External Air Temperature and Movement of Phase Center of Antenna (바깥 공기 온도의 일변화에 의한 GNSS 상시관측소 안테나탑 기울기 변화와 안테나 위상중심 위치의 운동 사이의 관계 추출)

  • Lim, Mu-Taek;Kwak, Byung-Wook;Park, Yeong-Sue;Rim, Hyoung-Rae
    • Geophysics and Geophysical Exploration
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    • v.12 no.2
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    • pp.208-214
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    • 2009
  • Using the GNSS data and tilt-meter data of Boeun (BOEN) and Goesan (GSAN) GNSS stations, we have calculated the differential distance vector variation with the calculation time span set to 1 hour and 3 hour and differential tilt vector variation along time and derived an indicator of similarity between the two variations along time. The similarity such calculated is rather lower than high. But as the existence of a circular type movement of the antenna's phase center's location due to the tilt's variation of the antenna tower because of the sunlight's diurnal change is certain, we recommend to take such diurnal variation of antenna's location into consideration when the correction error in DGNSS or the measured data at reference stations in VRS (Virtual Reference System) is broadcast.