• 제목/요약/키워드: Self-measurement

검색결과 1,506건 처리시간 0.027초

Novel velocity detection of moving object with rough surface vertically illuminated by self-mixing laser diode

  • Shibata, Takaaki;Shinohara, Shigenobu;Ikeda, Hiroaki;Yoshida, Hirofumi;Sumi, Masao
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.494-497
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    • 1994
  • We propose a novel velocity detection method of moving object based on a speckle pattern on the target surface using a self-mixing laser diode (SMLD). By this measurement, it was confirmed that the speckle signal has its waveform independent of the target velocity, and has its averaged frequency directly proportional to the target velocity. So it will be possible to detect the velocity of the target transversely translating against the laser light beam using a compact measuring system.

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네트워크 이동 환경에서의 TCP 성능 향상에 관한 연구 (A Study on TCP Efficiency Improvements from Network Mobile Environment)

  • 조현섭
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2011년도 춘계학술논문집 1부
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    • pp.375-378
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    • 2011
  • Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. We have advanced the framework of the multiple time scale congestion control and showed its effectiveness at enhancing performance for the rate-based feedback control.

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A New Approach for Built-in Self-Test of 4.5 to 5.5 GHz Low-Noise Amplifiers

  • Ryu, Jee-Youl;Noh, Seok-Ho
    • ETRI Journal
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    • 제28권3호
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    • pp.355-363
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    • 2006
  • This paper presents a low-cost RF parameter estimation technique using a new RF built-in self-test (BIST) circuit and efficient DC measurement for 4.5 to 5.5 GHz low noise amplifiers (LNAs). The BIST circuit measures gain, noise figure, input impedance, and input return loss for an LNA. The BIST circuit is designed using $0.18\;{\mu}m$ SiGe technology. The test technique utilizes input impedance matching and output DC voltage measurements. The technique is simple and inexpensive.

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확장된 PID 자기동조기의 설계 (Design of the Extended PID Self-Tuner)

  • 金鍾煥;崔桂根
    • 대한전자공학회논문지
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    • 제23권4호
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    • pp.439-444
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    • 1986
  • In this paper the PID-B self-tuner[1] is extended to allow a less abrupt response to set point or plant parameter changes and to control a nonminimum phase plant. The proposed extended PID/ST derived from the direct pole-placement PID/ST is obtained with the Bezout identity as the underlying design method. And its control gains are normalized by the integral control gain. Although the integral control gain is normalized to 1 in our scheme, the so-called "set point and derivative kick" can be avoided sufficiently by normalizing the measurement vector and set point.

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RHODIUM SELF-POWERED NEUTRON DETECTOR'S LIFETIME FOR KOREAN STANDARD NUCLEAR POWER PLANTS

  • YOO CHOON SUNG;KIM BYOUNG CHUL;PARK JONG-HO;FERO ARNOLD H.;ANDERSON S. L.
    • Nuclear Engineering and Technology
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    • 제37권6호
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    • pp.605-610
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    • 2005
  • A method to estimate the relative sensitivity of a self-powered rhodium detector for an upcoming cycle is developed by combining the rhodium depletion data from a nuclear design with the site measurement data. This method can be used both by nuclear power plant designers and by site staffs of Korean standard nuclear power plants for determining which rhodium detectors should be replaced during overhauls.

주파수 변환 귀환 방식의 광섬유 솔리톤 레이저에서 Self Heterodyne에 의한 펄스폭 측정 (Pulsewidth measurement by self-heterodyne in a frequency shifted feedback fiber soliton laser)

  • 윤승철
    • 한국광학회지
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    • 제10권1호
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    • pp.68-72
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    • 1999
  • 주파수 변환 귀환 방식의 광섬유 솔리톤 레이저에서 고진기 내의 광주파수 변화기를 이용하여 self-heterodyne 방식으로 펄스폭을 측정하엿다. 공진기 네에서 주파수 변환기를 통과하기 전과 후의 펄스열과 헤테로다인 시키고 두 펄스열 간의 지연길이를 가변 시키면서 맥놀이 주파수 성분의 세기를 측정함으로써 진폭 자기상관 함수를 얻었으며 이로부터 펄스폭을 측정할 수 있었다. 그 결과, 기존의 제2차 고조파 발생을 이용한 자기상관 방식과 r의 같은 결과를 얻었다.

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Self-Cleaning and Photocatalytic Performance of TiO2 Coating Films Prepared by Peroxo Titanic Acid

  • Yadav, Hemraj M.;Kim, Jung-Sik
    • 한국재료학회지
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    • 제27권11호
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    • pp.577-582
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    • 2017
  • Self-cleaning and photocatalytic $TiO_2$ thin films were prepared by a facile sol-gel method followed by spin coating using peroxo titanic acid as a precursor. The as-prepared thin films were heated at low temperature($110^{\circ}C$) and high temperature ($400^{\circ}C$). Thin films were characterized by X-ray diffraction(XRD), Field-emission scanning electron microscopy(FESEM), UV-Visible spectroscopy and water contact angle measurement. XRD analysis confirms the low crystallinity of thin films prepared at low temperature, while crystalline anatase phase was found the for high temperature thin film. The photocatalytic activity of thin films was studied by the photocatalytic degradation of methylene blue dye solution. Self-cleaning and photocatalytic performance of both low and high temperature thin films were compared.

Approach of Self-mixing Interferometry Based on Particle Swarm Optimization for Absolute Distance Estimation

  • Li, Li;Li, Xingfei;Kou, Ke;Wu, Tengfei
    • Journal of the Optical Society of Korea
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    • 제19권1호
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    • pp.95-101
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    • 2015
  • To accurately extract absolute distance information from a self-mixing interferometry (SMI) signal, in this paper we propose an approach based on a particle swarm optimization (PSO) algorithm instead of frequency estimation for absolute distance. The algorithm is utilized to search for the global minimum of the fitness function that is established from the self-mixing signal to find out the actual distance. A resolution superior to $25{\mu}m$ in the range from 3 to 20 cm is obtained by experimental measurement, and the results demonstrate the superiority of the proposed approach in comparison with interpolated FFT. The influence of different external feedback strength parameters and different inertia weights in the algorithm is discussed as well.

셀프레벨링 모르타르용 Primer 성상에 따른 특성평가에 관한 실험적 연구 (An Experimental Study on the Characteristics of Evaluation with Feature of Self Levelling Primer)

  • 강동균;김경덕;김정환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.505-508
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    • 2006
  • Self-leveling mortar is walkable bottom mortar which can maintain the horizontality of self fluid and have the the quick-setting quality, the low-human-effort practicable material of high-quality bottom in construction. In accordance with more adhesive strength with bottom side and absorption control, Primer is used for purpose to prevent pin-hole occurrence by self leveling mortar application prior to construction. This study is composed measurement of absorption, adhesive strength. Used material is NP-40 as nonionic emulsifying agent, uses SA-210L as negative ion emulsifying agent, uses APS, SBS as ridical initiator. A result of test, in accordance with image of Primer, as low temperature and application frequency, indicates low absorption rate and adhesive strength, as solid powder and dryness time is increse, absorption rate and adhesive strength lowly shows figure.

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Lifetime estimation of a covered overhead line conductor

  • Leskinen, Tapio;Kantola, Kari
    • Wind and Structures
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    • 제6권4호
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    • pp.307-324
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    • 2003
  • The paper presents results of studies concerning wind-induced aeolian vibration and fatigue of a 110 kV covered conductor overhead line. Self-damping measurement techniques are discussed: power method is found to be the most reliable technique. A method for compensating tension variations during the self-damping test is presented. Generally used empirical self-damping power models are enhanced and the different models are compared with each other. The Energy Balance Analysis (EBR) is used to calculate the aeolian vibration amplitudes, which thereafter are converted to bending stress for the calculation of conductor lifetime estimate. The results of EBA are compared with field measurements, Results indicate that adequate lifetime estimates are produced by EBA as well as field measurements. Generally the EBA gives more conservative lifetime expectancy. This is believed to result from the additional damping existing in true suspension structures not taken into account by EBA. Finally, the correctness of the line design is verified using Cigre's safe design tension approach.