• 제목/요약/키워드: Polarization measurement

검색결과 416건 처리시간 0.024초

동전위 분극저항 측정에서의 불확도 (Uncertainty in Potentiodynamic Polarization Resistance Measurement)

  • 김종집
    • Corrosion Science and Technology
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    • 제8권5호
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    • pp.193-196
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    • 2009
  • For the estimation of uncertainty in potentiodynamic polarization resistance measurement, the type A uncertainty was measured using type 316 stainless steel in an acidified NaCl solution. Sensitivity coefficients were determined for measurand such as scan rate of potential, temperature of solution, concentration of NaCl, concentration of HCl, surface roughness of specimen and flow rate of purging gas. Sensitivity coefficients were large for the measurand such as the scan rate of potential, temperature of solution and roughness of specimen. However, the sensitivity coefficients were not the major factors influencing the combined standard uncertainty of polarization resistance due to the low values of uncertainty in measurements of the measurands. A major influencing factor was the concentration of NaCl. The value of type A uncertainty was 1.1 times the value of type B uncertainty, and the combined standard uncertainty was 10.5 % of the average value of polarization resistance.

분극저항에 의한 온라인 부식속도 측정 시스템에 관한 연구 (Study on an On-line Measurement System of Corrosion Rate by Linear Polarization Resistance)

  • 문전수;이재근;이재봉;박필양
    • Corrosion Science and Technology
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    • 제11권4호
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    • pp.135-140
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    • 2012
  • The linear polarization resistance method is one of the widely used techniques for the corrosion rate monitoring in the water circulating systems of plants. The measurement is simple and rapid, so that a continuous on-line monitoring is possible without any shutdown of plants. A 2-electrode polarization corrosion rate measurement system was installed in a laboratory using a data acquisition board and PC. The signal processing parameters were optimized for the accurate corrosion rate measurement, and the polarization resistance was compensated with the solution resistance measured by the high frequency sine wave signal of an output channel. The precision of corrosion rate data was greatly improved by removing the initial noise signals on measuring the polarization resistance.

편광 유지형 광섬유의 검사 모니터링 시스템 개발 (Development of Monitoring System for Inspection of Polarization Optical Fiber)

  • 김재열;임종환
    • 한국공작기계학회논문집
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    • 제16권5호
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    • pp.145-150
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    • 2007
  • Optical communication according to request of technology of communications and optical fiber to be full filed faster communication and pass over transmission capacity limit per unit area, per unit hour appeared, and this optical fiber acts the biggest role to influence performance of optical communication network. Optical fiber(PMF Polarization Maintaining Fiber) is used, and is used by electric field measurement, self-discipline measurement, sensor(Sensor) Department by high definition measure such as thermometry and storehouse component that use because make broad sense status and polarized light information in passageway and union with storehouse integrated circuit etc. that use broad sense interference developing could transmit in state that keep transmitting broad sense plane of polarization is polarized light existence. Also, research is developed by optical fiber for Coherent communication recently.

복굴절이 큰 광섬유에 제작된 장주기 광섬유 격자를 이용한 광섬유 전류 센서 (Fiber-optic Ccurrent Sensor Using a Long-period Fiber Grating Inscribed on a High Birefringent Fiber)

  • 이용욱
    • 전기학회논문지
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    • 제56권10호
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    • pp.1823-1825
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    • 2007
  • Based on Faraday effect, the variation of current flowing through the conductor can be encoded as that of azimuth angle of light polarization propagating through the fiber coil wound onto the conductor. The amount of current can be obtained by measuring the variation of the light intensity transformed from that of the azimuth angle through a polarization analyzer. In this paper we propose a fiber-optic current sensor system that employs a fiber polarization analyzer as a sensor interrogation device. The fiber polarization analyzer was prepared by inscribing a long-period fiber grating on a high birefringent fiber. At the fixed wavelength of 1522.5 nm, the fabricated fiber device has the polarization extinction ratio of more than 25 dB. The measurement of large current up to 600 Arms was accomplished based on a simple fiber interrogation device and the measurement output of the sensor system showed a good linearity.

강유전체 분극 이력곡선의 측정 정밀도 향상 (Improvement of Precision in Ferroelectric Polarization Hysteresis Measurement)

  • 박재환
    • 마이크로전자및패키징학회지
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    • 제30권3호
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    • pp.51-55
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    • 2023
  • 강유전체 분극 이력곡선의 측정은 강유전체의 구조와 유전특성을 전반적으로 평가하고 해석하는 중요한 수단이다. 강유전체 시편에 저항성분이 포함될 경우 자발분극의 측정 값에 오차가 포함된다. 분극을 측정하는 전기적 회로를 구성할 때, 시편에 포함된 저항성분에 대응하는 외부 저항을 적절히 활용함으로서 시편의 저항성 손실에 의한 오차를 배제하고 내부에 유도된 강유전체 분극의 크기를 정확하게 측정할 수 있었다. 이와 같은 정확한 분극 이력곡선의 평가를 통하여 강유전체 내부의 이온의 변위 및 유전특성을 보다 정확하게 평가할 수 있을 것으로 기대된다.

다중경로페이딩 경감을 위한 원편파 다이버시티 시스템 제작 및 성능 평가 (The Fabrication and Performance Estimation of Circularly Polarization Diversity System for Multipath Fading Reduction)

  • 이주현;김판신;안재성;김태홍;고연화;김흥진;하덕호
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.609-612
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    • 2003
  • For combating multipath fading in wireless radio environment, diversity schemes is useful. In this paper, for performance improvement of polarization diversity system, we analyzed a two-branch polarization diversity at the receiving end of a mobile link when the transmitter emits a circularly polarized wave. And In order to calculate the correlation coefficient considering the XPD(cross polarization discrimination) between the received signals for the two diversity branches, a simple theoretical model of circular polarization diversity is adopted and calculate correlation coefficient. From the analysis results, it is seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of vertical polarization diversity. And also, we designed and fabricated circular polarization diversity system with microstrip antenna. we analyzed data measured in indoor NLOS environment using fabricated circular polarization diversity system. From the measurement results, it is clearly seen that the diversity effect of circular polarization diversity system is higher 3dB than vertical polarization diversity system.

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Angle of view polarization characterization of LCDs

  • Boher, P.;Bignon, T.;Leroux, T.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1615-1618
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    • 2007
  • Performances of LCDs are generally evaluated in terms of luminance and color versus viewing angle. In the present paper we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument can be used to measure the degree of polarization the light and the ellipticity and polarization direction of the polarized component. This measurement is made versus incidence angle between 0 and $88{\circ}$ and for all the azimuth angles. Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar.

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자이로용 Er-첨가 광섬유 광원에서 편광 스크램블링을 이용한 편광효과의 억제 (Suppression of polarization effects in Er-doped fiber source for gyroscope by polarization scrambling)

  • 김택중;진영준;박희갑
    • 한국광학회지
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    • 제14권4호
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    • pp.449-453
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    • 2003
  • 자이로스코프용 광대역폭 erbium 첨가 광섬유 광원에서 중심파장의 편광의존성을 억제하기 위하여 펌프광의 편광을 변조함으로써 스크램블링하는 방식을 사용하였다. 원통형 PZT에 광섬유를 감은 형태의 편광변조기에 적정진폭의 변조를 가함으로써 펌프광의 편광도(시간평균치)를 1.4%까지 낮출 수 있었다. 펌프 편광 스크램블러와 출력단 depolarizer를 함께 사용한 경우에 임의의 편광변화에 대한 광원의 중심파장 변화가 측정기의 측정한계(∼5 ppm) 이하로 관찰되었다.

백색광 마이켈슨 간섭계를 이용한 광섬유 고리의 편광 교차결합 측정 (Investigation of the Polarization Cross-Coupling in Fiber Coils Using White Light Michelson Interferometer)

  • 조민식;도재철
    • 한국군사과학기술학회지
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    • 제9권3호
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    • pp.109-115
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    • 2006
  • The investigation of the polarization cross-coupling in fiber coils was made using white light Michelson interferometer. The white light interferometer has a light source of about 13nm spectral bandwidth and measurement resolution of less than -80dB. The measurement found that the 200m fiber coil has a polarization cross-coupling of about -64dB in average and -46dB in maximum.

Oscillator Strength of Normal-incidence Intersubband Absorption in Conduction Bands of Si and Ge Quantum Wells Using Polarization

  • Lee, Chanho
    • Journal of Electrical Engineering and information Science
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    • 제3권1호
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    • pp.80-85
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    • 1998
  • A theoretical calculation and an optical measurement method of normal-incidence absorption are proposed. By using a waveguide structure, optical interference and the problem of low level signal can be avoided in the measurement of normal-incidence absorption. The oscillator strength of intersubband absorption for a waveguide structure is calculated in Si(001), Si(110), and Ge(001) quantum wells. The polarization angle dependence of the measured and the calculated absorption strength can be obtained with the same waveguide structure, and be compared after normalization. The normal-incidence absorption in Si(110) and Ge(001) quantum wells is shown theoretically, and can be observed in the optical measurement using waveguide structures at the polarization angle of 90$^{\circ}$.

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