• 제목/요약/키워드: Measurement Techniques

검색결과 1,914건 처리시간 0.032초

경사 충돌 제트 열전달 실험에서 정상 상태와 천이 TSP 기법의 비교 연구 (Comparative Study of the Steady State and Transient TSP Techniques in the Heat Transfer Measurement by an Inclined Impingement Jet)

  • 조용화;노영철;이용진;곽재수
    • 한국유체기계학회 논문집
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    • 제15권1호
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    • pp.5-12
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    • 2012
  • In this paper, the heat transfer coefficient measurement techniques using TSP(temperature sensitive paint) were introduced and the results of a comparative study on the heat transfer coefficient measurement by steady state and transient TSP techniques were discussed. The distributions of heat transfer coefficient by a single $60^{\circ}$ inclined impingement jet on a flat surface were measured by both techniques. Tested Reynolds number based on the jet diameter (d) was 30,000 and the distance between jet exit and target plate (L) was fixed at 10d. Results showed that the measured Nusselt number by both techniques indicated significant difference except near the center of impingement jet. Also, the heat transfer coefficients measured by the transient TSP technique were affected by the reference temperature of the jet. Based on the measured data, characteristics of both TSP techniques were analyzed and suggestions for applying them were also given.

Evaluation of Performances for Personal Robots

  • Ahn, Chang-hyun;Kim, Jin-Oh;Yi, Keon-Young;Kim, Jin-Oh
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.117.1-117
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    • 2002
  • $\textbullet$ Evaluation techniques of mobility $\textbullet$ Position characteristics $\textbullet$ Path characteristics $\textbullet$ Evaluation techniques of navigation $\textbullet$ Standard measurement environment $\textbullet$ Evaluation program and equipments $\textbullet$ A measurement experiment

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RF 스텔스용 RAM의 전파흡수능 측정기법에 관한 연구 (A Study on Measurement Techniques of EM Wave Absorbing Ability of a RAM for RF Stealth)

  • 최창묵;임봉택;고광섭
    • 한국정보통신학회논문지
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    • 제14권6호
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    • pp.1331-1337
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    • 2010
  • 본 논문에서는 국방과학의 RF 스텔스 구현을 위해 필요한 RCS 감소용 RAM의 전파흡수능 측정기법에 대하여 연구하였다. 먼저 RAM의 전파흡수능에 대한 이론 정립 후 측정기법에 대하여 실제 레이더 시스템과 유사한 자유공간법과 실험실에서 용이한 전송선로법을 분석하여 실제 RAM 샘플을 제작하여 측정기법에 따라 측정후 비교 분석하였다. 비교 분석결과 전파흡수능은 자유공간법에서 다소 우수한 특성이 보였으나 전체적인 패턴이 유사한 것을 확인하였다. 따라서 RAM 개발시 초기단계부터 최종단계까지 단계별/주파수별 제시하는 측정기법을 차등 적용한다면 보다 효과적으로 RAM을 개발 할 수 있을 것이다.

RAM 흡수능 측정기법 연구 (A Study on Measurement Techniques of Absorbing Ability for a RAM)

  • 최창묵;임봉택;고광섭
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2010년도 춘계학술대회
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    • pp.527-530
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    • 2010
  • 본 논문에서는 RCS 감소용 RAM의 흡수능 측정기법에 대하여 연구하였다. 먼저 측정기법 중 자유공간법과 전송선로법을 분석하고 실제 RAM 샘플을 제작하여 측정기법에 따라 측정 후 비교 분석하였다. 비교 분석결과 흡수능은 자유공간법에서 다소 우수한 특성이 보였으나 전체적인 패턴이 유사한 것을 확인하였다. 따라서 RAM 개발시 초기단계부터 최종단계까지 단계별/주파수별 제시하는 측정기법을 차등 적용한다면 보다 효과적으로 RAM을 개발 할 수 있을 것이다.

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Horn과 Anandan기법을 이용한 Optical flow 측정 (Measurement of optical flow using horn and anandan techniques)

  • 송석진;남기곤;이장명
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.685-688
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    • 1998
  • Measurement of optical flow is a core problem of matching through the analysis of image sequences. In this paper, horn's and anandan's techniques are analyzed to derive a better technique for matching. Experimental results show that Horn's technique has low accuracy in measuring the velocity of optical flow while anandan's technique has poor performaance for diverging images. Based upon this observation, a new technique for the measurement of optical flow is proposed.

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Industrial Applications of PIV/PTV Velocity Field Measurement Techniques

  • Lee Sang Joon
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2001년도 Proceedings of 2001 Korea-Japan Joint Seminar on Particle Image Velocimetry
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    • pp.23-35
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    • 2001
  • Due to advances in digital image processing, computer and optical hardware, it is possible to extract full flow information from visualized flow images. Recently, the PIV/PTV methods have been accepted as a reliable velocity field measurement technique. In my laboratory, several velocity field measurement techniques have been developed and they were applied to various thermo-fluid flow problems. In this paper, some of the industrial applications will be discussed. As a result, the PIV/PTV technique was proved to be a powerful tool for industrial fluid flow diagnosis.

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Simulated Indoor Pass-by 시스템에서의 최적 Microphone Array 형태와 검증

  • 유윤선
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2009년도 추계학술대회 논문집
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    • pp.225-228
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    • 2009
  • The simulated indoor pass-by noise measurement system is the tool to measure and evaluate the pass-by noise at the test laboratory, without doing measurement at the field. This measurement system can realize the precision measurement under the specific condition and overcome the limitations of the field measurement, i.e. weather conditions, repeatability, .. This measurement system is done in time domain process using the array techniques, which synchronizes the time signals. The reliability of the obtained result depends on the array shapes, which can generate the moving source effect. In this paper, the validations are checked focusing the time domain synchronization of the signals with the optimum microphone array shape.

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차음성능 측정에 있어서의 암소음의 영향의 저감 (1) (Recuction of the Influence of Background Noise in Sound Insulation Measurement)

  • 염성곤;다치바나히데끼
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.495-498
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    • 2004
  • In the sound insulation measurements, the influence of background (extraneous) noise is often serious problem and how to reduce its effect and to improve the signal-to-noise(S/N) ratio is an important theme. As the background noise, such extraneous noises as road traffic noise and machine noise often disturb the measurement. In laboratory measurements on specimens with high sound insulation performances, even the internal noise of the measurement system can become a problem. To improve the signal-to-noise ratio and to improve the measurement accuracy, various kinds of digital signal processing techniques can be applied. In this paper, four kinds of digital signal processing techniques are applied and their effectiveness is examined by a simple sound insulation measurement.

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모아레 원리를 이용한 스핀들의 반경방향 회전정도 측정 (Measurement of Radial Error Motions of a Rotating Spindle by Moire Topography)

  • 박윤창;김승우
    • 대한기계학회논문집
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    • 제17권11호
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    • pp.2723-2729
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    • 1993
  • Moire principles are applied to the measurement of the spindle radial error motion. As opposed to conventional techniques, no master cylinder or ball is needed in the measurement so that the offset and out-of-roundness errors of the master can be inherently eliminated. Two periodic circular gratings are used, one is made on the spindle and the other is held stationary on the reference frame. When the two gratings are seen superimposed during spindle rotation, an interference fringe pattern is observed from which the information on the eccentricity between the two gratings can be extracted with high precision. The optical design and fringe analysis techniques of a prototype measurement system are described in detail with exemplary measurement results.

저전류 측정을 위한 반도체 소자 특성 분석 시스템에서의 보상 기법 (Calibration Techniques for Low-Level Current Measurement in the Characteristic Analysis System for Semiconductor Devices)

  • 최인규;박종식
    • 센서학회지
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    • 제11권2호
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    • pp.111-117
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    • 2002
  • 본 논문에서는 반도체 소자의 특성 분석을 위한 시스템에서 측정 회로에 의해 발생하는 오차를 감소시켜 측정 정밀도를 개선시키기 위한 보정 과정을 제안하였다. 또한 pA 수준의 저전류 측정을 위해서 누설 전류, 오프셋 전류와 같은 오차 전류를 감소시키기 위한 보상 기법을 제안하였다. 보정계수는 마이크로프로세서에 의해 보정 과정에서 수집된 데이터로부터 구해진다. 수집된 데이터를 최소 자승 오차법을 사용하여 다항식으로 근사하는 방법으로 보정 계수를 계산하고 저장한다. 측정 시에는 마이크로프로세서가 저장된 보정 계수를 사용하여 측정 오차를 교정하여 준다. 실험 결과에서 nA 이상의 전류를 측정할 경우 측정 오차가 0.02% 이하를 가지며 pA 수준의 저전류도 0.2% 정도의 오차로 측정 가능함을 확인하였다.