• 제목/요약/키워드: Experimental measurements

검색결과 2,973건 처리시간 0.028초

New Experimental Investigation of Magnetic and Electric Fields in the Vicinity of High-Voltage Power Lines

  • Ghnimi, Said;Rajhi, Adnen;Gharsallah, Ali
    • Journal of Magnetics
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    • 제21권1호
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    • pp.102-109
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    • 2016
  • In this paper, the theoretical and experimental characteristics of magnetic and electric fields in the vicinity of high voltage lines are investigated. To realize these measurements and calculations, we have developed some equations for two overhead power line configurations of 150 kV (single circuit, double circuit), based on Biot-savart law, image and Maxwell theories, in order to calculate the magnetic and electric fields. The measurements were done to a maximum distance from the tower of 50 m, at a height of 1m from the ground. These experiments take into consideration the real situations of the power lines and associated equipment. The experimental results obtained are near to that of the Biot-Savart theoretical results for a far distance from the tower; and for a distance close to the power line, the results from the image theory are in good agreement with the experimental results.

다이오드 레이저를 이용한 배기가스 $O_2$ 농도 및 온도 동시 측정에 관한 실험적 연구 (The Experimental Study on Simultaneous Measurements of $O_2$ Concentration and Temperature of Flue Gas Using a Single Diode Laser)

  • 김세원;신명철;이창엽;윤성운;김영일
    • 한국연소학회지
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    • 제17권1호
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    • pp.12-21
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    • 2012
  • Simultaneous measurements of oxygen concentration and temperature using diode laser in the combustion environment are successfully accomplished. A single DFB type diode laser of 760 nm line centre frequency is used and the scanned-wavelength direct absorption spectroscopy method and wavelength modulation spectroscopy method are applied to measure absorption signals below 793 K temperature region. The experimental results show that oxygen concentration are measured within 1% accuracy and temperature are measured within 5% accuracy. This new method of simultaneous measurements of concentration and temperature with a single diode laser shows a great promise.

Identification of reinforced concrete beam-like structures subjected to distributed damage from experimental static measurements

  • Lakshmanan, N.;Raghuprasad, B.K.;Muthumani, K.;Gopalakrishnan, N.;Basu, D.
    • Computers and Concrete
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    • 제5권1호
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    • pp.37-60
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    • 2008
  • Structural health monitoring of existing infrastructure is currently an important field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical and important structures. The paper outlines two methods of system identification of beam-like reinforced concrete structures representing bridges, through static measurements, in a distributed damage scenario. The first one is similar to the stiffness method, re-cast and the second one to flexibility method. A least square error (LSE) based solution method is used for the estimation of flexural rigidities and damages of simply supported, cantilever and propped cantilever beam from the measured deformation values. The performance of both methods in the presence of measurement errors is demonstrated. An experiment on an un-symmetrically damaged simply supported reinforced concrete beam is used to validate the developed method. A method for damage prognosis is demonstrated using a generalized, indeterminate, propped cantilever beam.

선미변동압력 계측시험에서의 불확실성 해석 (Measurement Uncertainty Analysis for Fluctuating Hull Pressure)

  • 최군일
    • 대한조선학회논문집
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    • 제30권4호
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    • pp.46-60
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    • 1993
  • 캐비테이션 터널에서 변동압력의 정확한 계측은 실선에서의 진동과 소음세기 예측에 필요하다. 본문에서는 프로펠러 케비테이션에 의해 야기되는 변동압력의 실험적연구 결과를 나타내고 논의 한다. 문제시 되고 있는 프로펠러 회전수에 의한 영향을 이해하고자 변동압력을 캐비테이션 터널에서 평판을 이용하여 여러 회전수에서 계측 하였다. 균일류에서 오차를 추정하기 위하여 계측 및 계측결과에서의 불확실성 해석이 사용 되었다.

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천수에서의 슬래밍 현상에 대한 실험적 연구 (An Experimental Study on Shallow Water Effect in Slamming)

  • 강효동;오승훈;권순홍
    • 한국해양공학회지
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    • 제23권1호
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    • pp.60-66
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    • 2009
  • This study presents an experimental investigation of the shallow water impact of a box type structure. The analysis was done based on the video images captured by a high speed camera, the flow field obtained by PIV (Particle Image Velocimetry), and pressure measurements in the divided region. The video images showed quite good agreement with the description given by Korobkin. The PIV measurements of the velocity field provided a clear view of the flow pattern for all three stages. The pressure was measured at the bottom of the tank with strain gauge type pressure gauges. The pressure measurements showed the characteristics of divided regions.

Lymphadenoid가 Hypertrophy된 아동과 정상아동간의 Tongue, Mandible 및 Hyoid bone의 위치비교에 관한 연구 (A COMPARATIVE STUDY OF THE TONGUE MANDIBLE AND HYOID BONE POSITION BETWEEN THE ADENOID HYPERTROPHIED CHILDREN AND THE NORMAL CHILDREN)

  • 이공근;유영규
    • 대한치과교정학회지
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    • 제16권2호
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    • pp.99-106
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    • 1986
  • The author studied 21 adenoid hypertrophied children and 50 normal children by the horizontal, vertical and angular measurements to analyze, the effects of the lymphadenoid hypertrophy to the tongue, mandible, and hyoid bone position. The results were as follows; 1. The tongue of the Adenoid hypertrophy children was positioned mon anterior and lower than that of the normal children. 2. The horizontal, vertical, and angular measurements of the mandible position were larger in the experimental group and especially ANS to ME, PNS to MP, PTM to MP, PP to MP, FOP to MP showed statistically significant difference. 3. The measurements of the hyoid bone position were also larger in the experimental group.

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Determination of the Size Distribution of Magnetite Nanoparticles from Magnetic Measurements

  • Yoon, Sung-Hyun
    • Journal of Magnetics
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    • 제16권4호
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    • pp.368-373
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    • 2011
  • Particle size distributions in 10 nm magnetite ferrofluids are analyzed based on both dc and ac magnetic measurements. Modified log-normal distributions are used for fitting the experimental results, which allows for a proper account of the narrow distributions. The calculated average particle sizes are in good agreement with the TEM results. However the ac method gives a much narrower distribution width than that of the dc magnetization curve fit. The proposed measurements combined with the analysis methods are useful for the characterization of ferrofluids being considered for biomedical applications.

비만여성의 일대일 맞춤거들 패턴에 대한 연구 (A Study on the Pattern of Custom-Made Girdles for Obese Women)

  • 남윤자;이준옥
    • 대한인간공학회지
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    • 제21권2호
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    • pp.71-86
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    • 2002
  • This study's purpose is to gain basic data for the factory automation of manufacturing custom-made girdles. For this study , obese women in their 30s and 40s was experimented through direct measuring and by the 3D scanner, by means of which the proportions of the subject's body was measured. Based upon the results of this experiment, individually designed girdles were made. In order to gain the basic data for the factory automation of manufacturing custom-made girdles, the patterns and the clothing pressure and the feeling of wearing such girdles were analyzed. This study can be summarized as follows: The material properties and the designs of existing functional girdles in the market were studied thoroughly, and the subject were required to wear those existing girdles. On the basis of this result, the experimental girdles were designed and produced which could serve well the subject's intension. The experimental girdles were of the basic long-type in order to apply to all sorts of girdles, and they were produced according to the style and pattern of the existing grading system. The second experiment was conducted by applying the subject's body measurements. Due to the elasticity of the material, in girdles the smaller measurements were to be used in this second experiment were: 80% of waist size, 84% of the hip and 85% of the thigh. To determine the length of the girdles, the same measurements were applied. The test results of the feeling of wearing the experimental girdles showed that the second, custom-made experimental girdles were better. According to the test results of the clothing pressure, the second experimental girdles(custom-made girdles) marked the higher pressure than the first on every part of the body, especially on the hips and thighs. Thus, it can be said that the second experimental girdles are better than the first in lifting up the hips. It is expected that the design methods developed in this study can be utilized as basic resources for the factory automation system of manufacturing custom-made girdles.

중간볼기근 강화운동이 만성 발목염좌 환자의 발목 안정성에 미치는 효과 (The Effects of Gluteus Medius Strength Training on Ankle Stability in Patient with Chronic Ankle Sprains)

  • 김윤환;박수형;송현승
    • 대한정형도수물리치료학회지
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    • 제24권2호
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    • pp.59-67
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    • 2018
  • Background: The purpose of this study was to investigate the effects of gluteus medius strength exercise on the ankle stability of high school student with chronic ankle sprains. Methods: A total of 30 participants were divided two groups. Experimental group was 15 participants applied gluteus medius strength exercise. Control group was 15 participants performing ankle strength exercise. This study was performed for 50 minutes per day, three a week for 6 weeks. All measurements were taken to a pre and post test. Strength was measured using Power Track ll. Balance was measured using Biodex balance system for Limits of Stability and Postural Stability. Ankle Stability was measured using Cumberland Ankle Instability Tool (CAIT). Results: In the case of gluteus medius strength, there were statistically significant differences between the experimental group and the control group. For ankle stability were statistically significant differences within the experimental group according to measurements taken by Limits of Stability, Postural Stability, and CAIT. A between group comparison showed a statistically significant difference for CAIT only. Conclusion: According to our measurements it appears that gluteus medius strength training was effective in benefiting muscular strength, balance and ankle stability among the physical education.