• Title/Summary/Keyword: length measurement

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Measurement of Electrical Treeing Length and Area by Use of Image Processing (영상 처리 방법을 이용한 트리 길이와 열화면적 계측)

  • 백관현;김재환
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.8 no.1
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    • pp.57-62
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    • 1994
  • In this paper, a system for measuring of treeing degradation in organic dielectric material by using image processing technics, is discussed. Traditionally, treeing is measured by visual method. It made difficulty to understanding for features and changes in the configlEation of the tree growth. Using image processing system, it is made to describe the characters of the tree growth, specially length of tree and area of treeing degradation. From this image processing and visual measurement, the similar results were made, an automatic measurement system was made for configuration of the tree growth.

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The Comparative Analysis on the Radiography of Long Bone Measurement by CT Scanogram and Conventional Method (CT Scanogram과 고식적방법에 의한 장골계측촬영의 비교분석)

  • Kim, Seung-Kook;Jeon, Jae-Doo
    • Journal of radiological science and technology
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    • v.24 no.2
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    • pp.29-33
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    • 2001
  • The accurate measurement for a long bone have taken an important part in orthopedics surgical diseases when the length of extremities is different each other. However, it is true that various kinds of methods to search for the accurate measurement on used in medical centers. In this study, we measured the real length of long bone for CT Scanogram and F.F.D by 100cm and 200cm in the angle of inclination $0^{\circ},\;3^{\circ}$ and $7^{\circ}$. This method will be useful to diagnose and treat patients more accurately.

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Measurement of Acoustic Properties and Prediction of Acoustic Performance of Porous Woven Hoses for Engine Intake Systems (엔진 흡기계에 쓰이는 다공형 직조관의 음향특성 측정 및 성능예측)

  • Park, C.M.;Ih, J.G.;Nakayama, Y.;Kitahara, S.;Takao, H.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.182-186
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    • 2000
  • The porous woven hose is recently considered as an effective element of automotive intake systems. In order to predict the acoustic performance of an intake system with a porous woven hose, the information on the acoustic wall impedance is required. In this article, a measurement technique that is valid over the low frequency range and without mean flow condition is presented. The measurement is performed in a cylindrical chamber with a concentric layout of the sample and the resistance is estimated from measured reactance and transmission loss data. It is observed that the measured transmission loss for a porous woven hose with an arbitrary length agrees well with the predicted one that uses the estimated impedance for a small sample length.

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3-Dimensional Measurement of the Cylindrical Object Using Computer Vision (컴퓨터 비젼을 이용한 원기둥형 물체의 3차원 측정)

  • Jang, TaekJun;Joo, Kisee;Han, Min-Hong
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.12
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    • pp.38-44
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    • 1995
  • This paper presents a method to measure the position and orientation of a Cylindrical Object(unknown the eiameter and length) lying on a floor, using a camera. The two extreme cross section of the cylinder will be viewed as distorted ellipese or circular are, while its limb edge will be shown as two straight lines. The diameter of the cylinder is determined from the geometric properties of the two straight lines, which in turn provides information regarding the length of the cylinder. From the 3-dimensional measurement, the 3D coordinates of the center points of the two extreme cross sections are determined to give the position and orientation of the cylinder. This method is used for automated pick-and-place operations of cylinder, such as sheet coils, or drums in warehouses.

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Experimental study on the correlation between measurement length and winding or twist pitch for magnetization loss occurring in CORC and TSTC

  • Ji-Kwang Lee;Jinwoo Han;Kyeongdal Choi;Woo-Seok Kim
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.4
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    • pp.40-44
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    • 2023
  • For high-temperature superconducting power applications that need large current capacity, a large current conductor manufactured using multiple superconducting tape is required. Conductors being studied for large currents capacity such as CORC, TSTC, and RACC have advantages and disadvantages, and in order to use these conductors in coil form and apply them to AC power devices, research on magnetization loss occurring in superconductors due to external magnetic fields is essential. To accurately measure magnetization loss in a conductor that is twisted by stacking straight conductors like TSTC, the correlation between the measuring system and the shape of the sample must be clearly known to accurately measure the loss. In this paper, we will confirm the difference in magnetization loss measurement values according to the correlation between the length of the pickup coil and the twist pitch of the sample in CORC and TSTC shapes, and review considerations for accurate magnetization loss measurement from the results.

Measurement of Transfer Length for a Seven-Wire Strand with FBG Sensors (FBG 센서를 이용한 강연선 전달길이 측정)

  • Lee, Seong-Cheol;Choi, Song-Yi;Shin, Kyung-Joon;Kim, Jae-Min;Lee, Hwan-Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.707-714
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    • 2015
  • In this paper, an experimental program has been conducted to investigate transfer length in high strength concrete members pretensioned through a seven-wire strand with FBG sensors. To measure transfer length, five members were fabricated, which had a length of 3 m and a cross-section of $150{\times}150mm$. It was measured that the concrete compressive strength was 58MPa at pretensioning. Test results indicated that more precise and reliable measurement on the transfer length was attained with FBG sensors than conventional gauges attached on concrete surface. Through comparing the measured transfer length and predictions, applicability of several transfer length models in literature was investigated. This paper can be useful for relevant research field such as investigation on the bond mechanism of a seven-wire strand in concrete members.

Effects of a Teaching Process using Dynamic Assessment : Young Children's Measurement Ability (참조물을 활용한 역동적평가의 교수과정이 유아의 측정능력에 미치는 영향)

  • Ko, Eun-Mi;Jung, Myung-Sook;Hwang, Hae-Ik
    • Korean Journal of Child Studies
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    • v.29 no.1
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    • pp.275-292
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    • 2008
  • This study investigated the effects of a teaching process using dynamic assessment for a unit on young children's measurement ability. Subjects were 45 5-year-old children in a kindergarten in Busan. The instrument was the Dynamic Assessment Tools for Young Children's Measurement Ability (Hwang & Ko, 2(07). Assessment consisted of four steps: pre-test, learning, transfer, post-test. Results were that at post-test, there were significant differences in scores of measurement ability between the dynamic assessment and control groups. In the dynamic assessment group there was significant improvement in length, width and weight between pre- and post-tests and there were significant shifts of measurement strategies and measurement errors between the pre- and post-tests.

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Study on the Estimation of Measurement Uncertainty in MOI Measurement (관성모멘트 측정에서의 불확도 추정기법 연구)

  • Kim, Kwang-Ro;Lee, Young-Shin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.6
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    • pp.797-802
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    • 2013
  • In this paper, using the mass/CG measurement equipment and the MOI measurement equipment developed in-house, Pitch MOI and Roll MOI of test specimen were measured and measurement uncertainties on MOI were studied. The possible factors of the measurement uncertainty that could affect accuracy of MOI measurement were mass, spring, frequency, and length measurement-related elements. The each combined standard uncertainty of pitch MOI and roll MOI was estimated from the uncertainties of the above various factors.