• 제목/요약/키워드: Range measurement

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하중에 따른 구조물 변위계측을 위한 근접수치사진측량의 정확도 분석 (Accuracy Analysis of Close-Range Digital Photogrammetry for Measuring Displacement about Loading to Structure)

  • 최현;안창환
    • 대한토목학회논문집
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    • 제29권4D호
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    • pp.545-553
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    • 2009
  • 본 연구는 구조물의 변위계측에 있어 비접촉방법인 디지털 카메라를 이용한 근접수치사진측량을 이용한 실험결과를 제시한 것이다. 근접수치사진측량을 구조물 변위계측에 적용하기 위하여 본 연구에서는 카메라 자체검정을 통하여 기하학적 해석 정확도를 저해하는 렌즈의 왜곡에 대한 보정을 실시한 후 구조물의 변위계측을 위하여 자체제작한 라멘구조물에 각각의 하중을 재하하여 변위계측을 실시하였다. 또한 변위계측시 현장 적용성을 높이기 위하여 구조해석 프로그램인 MIDAS를 이용하여 모델링한 후 비교분석하였다. 그 결과 현재 구조물 안전진단에 활용되고 있는 LVDT, 케이블식변위계등 접촉식변위계가 가지고 있는 단점인 현장접근의 어려움, 설치비 과다등의 단점을 극복할 수 있는 가능성을 제시하였으며, 특히 실측 시간의 단축으로 인한 경제성을 확보할 수 있었다. 따라서 디지털 카메라를 이용한 근접수치사진측량은 구조물의 변위계측 뿐만 아니라 구조물의 3차원 모델링, 구조물의 실측형상재현 등 시각적 분석이 필요한 분야에 다양하게 활용될 수 있을 것으로 판단된다.

발목관절 복합체의 가동범위 측정을 위한 중립위치와 측정방법의 신뢰도 (Reliability of the Joint Neutral Position and Measurement Methods of the Ankle Joint Complex Range of Motion)

  • 홍완성;김기원
    • The Journal of Korean Physical Therapy
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    • 제23권4호
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    • pp.45-51
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    • 2011
  • Purpose: To determine the correct measurement methods of the ankle joint complex range of motion for measuring the neutral position and evaluate the rater reliability. In addition, the impact of training on the rater reliability was also assessed. Methods: The subjects were eleven healthy women, who were evaluated by two physical therapists and one physical therapist recorded the results of the study. Standard goniometer was used as the measurement tool. The ankle and subtalar joint neutral position and the active range of motion of the ankle and subtalar joint were measured. Intra-rater reliability and inter-rater reliability measures were analyzed with intraclass correlation coefficients. Results: Intra-rater reliability and inter-rater reliability ranged from high to medium for the neutral position of the ankle joint complex. Intra-rater reliability for dorsiflexion and plantarflexion measurements was medium, while the inter-rater reliability was high. The range of motion of the subtalar joint was measured, and the intra-rater reliability and inter-rater reliability were low and medium, respectively Also, the intra-rater reliability was increased with formal training of the measurement techniques. Intra-rater reliability was reduced in case the raters had not undertaken the training. Conclusion: In summary, the results obtained with the measurement tools and joint measurement of position, indicate the consistency of repeated measurements made by the same observers. Under the same circumstances along with repetition of the same measurement technique during training caused an increase in the rater reliability of formally trained raters.

A Novel Range Estimator for Surface to Air Missile with Closing Velocity Measurements

  • Ra, W.S.;Whang, I.H.;Lee, J.I.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1822-1825
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    • 2003
  • A practical range estimator based on the robust Kalman filter is proposed to solve the range estimation problem for surface to air missile(SAM) homing guidance. Apart from the previous works based on the extended Kalman filter(EKF) with bearing only measurement, the proposed scheme makes use of line-of-sight(LOS) rate to ensure the fast convergency at long-range. In this reason, the robust Kalman filter is considered to deal with LOS rate measurement error. The recursive linear structure of proposed filter is easy to implement and make it possible to reduce computational burdens. Moreover, it shows good estimation performance without specific guidance law such as oscillation proportional navigation guidance(OPNG).

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다회선 초음파 유량계를 이용한 거래용 오일유량 측정 (Custody Transfer Hydrocarbon Flow Measurement with Multi-path Ultrasonic Flow Measurement)

  • 황상윤;이호준;박기환
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.149-153
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    • 2003
  • As the fastest growing flowmeter technology, multi-path ultrasonic flow-meters are gaining wider range in petroleum industry for liquid hydrocarbon custody transfer measurement. This paper describes the mult-path ultrasonic flowmeter, URO-Ex1000 the requirements necessary to prove and test in Korea & China. URO-Ex1000 haver a good results with accuracy range, but a little exceed with repeatability.

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중국 성인여성의 직접계측과 3D Body scanning 치수 비교 연구 (Comparison of Size between direct-measurement and 3D body scanning)

  • 차수정
    • 패션비즈니스
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    • 제16권1호
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    • pp.150-159
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    • 2012
  • This study intend to analyze differences between 3D body scanning sizes and direct measurement sizes of same subjects. The subjects of study are female students of university in China. 3D data analyze as a 3D Body Measurement Soft System. The conclusion found is as below: In case of circumferences, error between direct-measurement size and 3D body scanning size is from 4.9mm to 62.2mm. The neck circumference size of directmeasurement is bigger than 3D body scanning size. The height error range is from 0.6mm to 51mm. Height of underbust, waist and hip are that direct-measurement sizes are higher than 3D body scanning sizes. Gap of width is from 3.8mm to 21.9mm. The gap range is too narrow relatively to others. Only direct-measurement size of neck width is wider than 3D body scanning size. Error range of length is from 0.3mm to 41.8mm. 3D body scanning sizes of lateral neck to waistline, upperarm length, arm length, neck shoulder point to breast point, shoulder center point to breast point, lateral shoulder to breast point are longer than direct-measurement sizes. They have a negative margin of error. I intend to set up same measurement point between direct-measurement and 3D body scanning but they have some errors because direct-measurement point is applied by a person. 3D body scanning measurement point is settled by automatic system. A measurement point of direct-measurement and 3D body scanning isn't unite. So we need to make a standard of setting up measurement points.

Low Cost Omnidirectional 2D Distance Sensor for Indoor Floor Mapping Applications

  • Kim, Joon Ha;Lee, Jun Ho
    • Current Optics and Photonics
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    • 제5권3호
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    • pp.298-305
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    • 2021
  • Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

Two-Site Optical Observation and Initial Orbit Determination for Geostationary Earth Orbit Satellites

  • Choi, Jin;Choi, Young-Jun;Yim, Hong-Suh;Jo, Jung-Hyun;Han, Won-Yong
    • Journal of Astronomy and Space Sciences
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    • 제27권4호
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    • pp.337-343
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    • 2010
  • Optical observation system provides angle-only measurement for orbit determination of space object. Range measurement can be directly acquired using laser ranging or tone ranging system. Initial orbit determination (IOD) by using angle- only data set shows discrepancy according to the measurement time interval. To solve this problem, range measurement data should be added for IOD. In this study, two-site optical observation was used to derive the range information. We have observed nine geostationary earth orbit satellites by using two-site optical observation system. The determination result of the range shows the accuracy over 99.5% compared to the results from the satellite tool kit simulation. And we confirmed that the orbit determination by the Herrick-Gibbs method with the range information obtained from the two-site observation is more accurate than the orbit determination by Gauss method with the one-site observation. For more accurate two-site optical observation, a baseline should satisfy an optimal condition of length and more precise observation system needed.

변별기 추정방식을 적용한 다기능 레이다용 거리 및 속도 측정 알고리즘 성능 분석 (Performance Analysis of Range and Velocity Measurement Algorithm for Multi-Function Radar using Discriminator Estimation Method)

  • 최병관;이범석;김환우
    • 대한전자공학회논문지SP
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    • 제42권1호
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    • pp.109-117
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    • 2005
  • 거리 및 속도 측정 알고리즘은 거리 및 도플러 주파수 영역에서 등 간격으로 구성된 정합필터 출력을 이용하여 정밀한 표적 위치를 추정하는 과정이다. 특히 다기능 레이다용 측정 알고리즘은 동시에 다 표적 추적이 가능하도록 정밀도 뿐만 아니라 수행시간에 대한 고려가 필요하다. 본 논문에서는 모노 펄스(monopulse) 레이다 각도추정에 사용되는 변별기(discriminator)추정방식을 거리 및 속도 측정에 적용하여 알고리즘 성능분석 결과를 제시한다. 적용된 추정방법은 추정 시 수행시간이 일정하므로 다중 표적 추적에 적합하다. 하지만 최소한의 채널 출력만을 이용한 추정방법이므로 측정 정밀도에 대한 고려가 필요하다. 컴퓨터 모의실험을 통해 기존 무게중심 추정방식의 측정 알고리즘과 정밀도 측면에서 성능을 비교하여 적용한 방법의 우수성을 보이고, 또한 펄스 폭, 채널 간격 등 프로세싱 변수 변화에 따른 RMS 에러 계산을 통해 알고리즘 자체 특성을 분석한다.

Quantitative study of acupuncture manipulation of lifting-thrusting using an needle insertion-measurement system in phantom tissue

  • Lee, Soo-Yoon;Son, Young-Nam;Choi, In-Hwa;Shin, Kyung-Min;Kim, Kap-Sung;Lee, Seung-Deok
    • 대한한의학회지
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    • 제35권4호
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    • pp.74-82
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    • 2014
  • Objectives: Quantification, objectification, and standardization of lifting-thrusting manipulation are important issues in traditional Chinese medicine (TCM). The purpose of this study was to quantitatively investigate the difference in the amount of stimulation according to range and frequency among parameters of lifting-thrusting manipulation with the use of a needle insertion-measurement system. Methods: For quantification of lifting-thrusting manipulation, an acupuncture needle insertion-measurement system was used in phantom tissue. The motor and force sensors of the needle insertion device were connected to the control software. This enabled operation of the lifting-thrusting manipulation and measurement of the acupuncture needle force. The measurement of the acupuncture needle force according to various frequencies (0.25, 0.50, 0.75, and 1 Hz) and ranges of movement (2, 4, 6, 8, and 10 mm) was repeated 10 times. Results: At a constant frequency of movement, acupuncture needle force according to range of movement (2, 4, 6, 8, and 10 mm) increased with increasing range of movement (p < 0.05). At a constant range of movement, acupuncture needle force according to frequency of movement (0.25, 0.50, 0.75, and 1.0 Hz) increased with increasing frequency of movement (p < 0.05). Conclusion: In this study, we conducted a quantitative comparison of the amount of stimulation according to range and frequency, the main parameters of lifting-thrusting manipulation, by using an acupuncture needle insertion-measurement system. Future studies on various manipulations and parameters are warranted to quantify and objectify the amounts of stimulation by acupuncture manipulation.

목말밑관절 가동범위 측정방법에 관한 연구 (A Study of Measurement Methods for Subtalar Joint Motion)

  • 김기원;홍완성
    • The Journal of Korean Physical Therapy
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    • 제22권4호
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    • pp.57-64
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    • 2010
  • Purpose: This study aimed to determine whether there are differences in subtalar joint range of motion (ROM) when using different measurement methods, and to determine inter- and intra-rater reliability of goniometry as used in clinical setting. Methods: Subjects were thirty-one healthy males and females (sixty-two ankles) living in Korea. Three raters with different clinical experiences measured inversion and eversion range of motion of the subtalar joint two times. Measurements were done with subjects prone (open kinetic chain) and standing (closed kinetic chain). Rater and measurement methods were based on analyzing differences in range of motion. Intra-class correlation coefficients (ICCs) were calculated to determine intra-rater and inter-rater reliability. Results: Mean subtalar jont range of motion for inversion ranged from $9.31^{\circ}$ to $11.94^{\circ}$ for eversion, it ranged from $6.73^{\circ}$ to $9.20^{\circ}$. The differences in ROM between raters and between measurement methods were significant (p<0.01). The ICCs for interrater reliability ranged from $0.02^{\circ}$ to $0.20^{\circ}$ for inversion and from $0.23^{\circ}$ to $0.39^{\circ}$ for eversion. Intrarater reliability ranged from $0.32^{\circ}$ to $0.78^{\circ}$ for inversion and from $0.45^{\circ}$ to $0.73^{\circ}$ for eversion. Conclusion: Subtalar joint inversion and eversion ROM show differences for measurement methods low reliability between different raters, and low to high intra-rater reliability within sessions.