• 제목/요약/키워드: estimated availability

검색결과 225건 처리시간 0.031초

Local Bandwidth Selection for Nonparametric Regression

  • Lee, Seong-Woo;Cha, Kyung-Joon
    • Communications for Statistical Applications and Methods
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    • 제4권2호
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    • pp.453-463
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    • 1997
  • Nonparametric kernel regression has recently gained widespread acceptance as an attractive method for the nonparametric estimation of the mean function from noisy regression data. Also, the practical implementation of kernel method is enhanced by the availability of reliable rule for automatic selection of the bandwidth. In this article, we propose a method for automatic selection of the bandwidth that minimizes the asymptotic mean square error. Then, the estimated bandwidth by the proposed method is compared with the theoretical optimal bandwidth and a bandwidth by plug-in method. Simulation study is performed and shows satisfactory behavior of the proposed method.

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관성항법시스템을 이용한 구륜 이동 로보트의 위치제어에 관한 연구 (A study on position control of wheeled mobile robot using the inertial navigation system)

  • 박붕렬;김기열;김원규;박종국
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1144-1148
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    • 1996
  • This paper presents WMR modelling and path tracking algorithm using Inertial Navigation System. The error models of gyroscope and accelerometers in INS are derived by Gauss-Newton method which is nonlinear regression model. Then, to test availability of error model, we pursue the fitness diagnosis about probability characteristic for real data and estimated data. Performance of inertial sensor with error model and Kalman filter is pursued by comparing with one without them. The computer simulation shows that position error remarkably decrease when error compensation is applied.

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공항철도 신호시스템 전자연동장치에 대한 RAM 예측 (RAM Prediction of Signaling Interlocking System for AREX)

  • 송미옥;임성수;이창환;권민혁
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.255-261
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    • 2007
  • In this paper we introduce the method, procedure and result of RAM prediction for interlocking system which is applied for AREX signaling system. For RAM prediction, we breakdown the interlocking system to the LRU level and select the LRUs of which failure can cause the service delay. The prediction of reliability is based on the Reliability Block Diagram which is the functional diagram composed of selected LRUs and finally, the availability of interlocking system is estimated from the combination of reliability and maintainability.

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한반도의 태풍 동반 강우의 통계적 예측 (Statistical Estimation of Typhoon-Induced Rainfall around Korean Peninsular)

  • 구혜윤;이승수;이영규
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.93-96
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    • 2008
  • Considering the loss due to typhoon is increasing, estimation and analysis of a typhoon's influence has become more important. On this basis, the statistical models were presented in this paper by two principal elements. Comparisons between the estimated rainfall rate of these models and the observed value in the duration of Typhoon NARI(2007) were analyzed to confirm the availability of these models.

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Reliability Analysis of Diesel Generators of Wolsong Unit 1

  • Park, S. Y.;Kim, S. H.;Kim, K. Y.;Kim, T. W.;Y. S. Cho
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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    • pp.502-507
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    • 1997
  • As a maintenance optimization project to improve the safety of Wolsong NPP (Nuclear Power Plant), reliability of diesel generators are estimated based on the operating experience, and improvement options are suggested. A reliability measure is suggested for the estimation of reliability for standby safety systems to reflect availability. It is assessed that the reliability of diesel generators can be much improved if the suggested improvement options are implemented.

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Performance Evaluation of Motor-Operated Valve Using Electrical Signatures

  • Park, Joo-Moon;Joo, Hyung-Jun;Jung, Jae-Cheon;Sung, Key-Yong;Seong, Se-Jin
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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    • pp.52-55
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    • 2001
  • This paper is to see the availability of electrical signatures as a means for evaluating the performance and monitoring mechanical anomalies of (MOVs). To estimate motor torque, two methods such as d-q frame conversion and air-gap method are suggested and estimated results are compared with measured values. The error between measured and estimated torques is within acceptable error bound with below $1\%$ under varied load. Frequency domain analysis of calculated torque has been done as well. It is shown that monitoring of peak frequency could give useful clues to detect anomalies of MOV. As results, electrical signatures at MOV motor is expected to be an available tool for estimation of motor capacity and monitoring of electrical and mechanical abnormalities.

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실외조명 LED용 SMPS의 가속수명시험법 제안 (Suggested Accelerated Life Test Method of SMPS for Outdoor Lighting LED)

  • 임성용;형재필;임홍우;오근태
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제18권1호
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    • pp.8-19
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    • 2018
  • Purpose: This study has developed the accelerated lifetime test method for smps for outdoor lighting LED through two factors of temperature and humidity. Methods: Acceleration condition was confirmed for each stress and model, and acceleration life test model was estimated according to acceleration condition. Results: As a result of confirming the accelerated life test model, in the case of humidity, acceleration was established only in the foreign products. Therefore, it is confirmed that the acceleration condition is insufficient. However, the estimated parameters for temperature are relatively constant. It is therefore suitable for power supply acceleration tests for outdoor lighting LEDs. Conclusion: The SMPS acceleration test for outdoor lighting LED can improve the availability of the product by developing an accelerated life test method that guarantees the reliability of the product.

RGB 색신호에 의한 피부색의 분광반사율 추정 (The method to predict spectral reflectance of skin color by RGB color signals)

  • 김채경;박상택;김종필;이을환;안석출
    • 한국인쇄학회지
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    • 제16권3호
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    • pp.97-108
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    • 1998
  • Spectral reflectance of the object should be measured to predict the color of object under various illuminants. The spectral reflectance can be represented in a multi-dimension space. Generally the information of inputed image by digital camera and color scanner is represented with 3-dimension color signals such as RGB. In other to predict the color of inputed image under any illuminant, we should be estimated spectral reflectance of the object. In this paper, we described the method to predict spectral reflectance by einenvector using the skin color of printed image, confirmed availability and propriety through experiment. we estimated spectral reflectance of skin color taken by RGB color signals and than reproduced skin color according to various illuminants on CRT.

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모터 구동밸브 성능 및 고장감시 기술개발 (Development of Condition and Performance Monitoring Technology of MOV)

  • 주형준;박주문;오성업;성세진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2002년도 전력전자학술대회 논문집
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    • pp.739-742
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    • 2002
  • This paper is to see the availability of electrical signatures as a means for evaluating performance of MOVs which are extensively used in safety-related systems in nuclear plants. To estimate motor torque, two methods such as d-q frame conversion and air-gap method are suggested and estimated results are compared with measured values. The error between measured and estimated torques is within acceptable error bound with below $1\%$ under varied load. Frequency domain analysis of calculated torque has been done as well. It is shown that monitoring of peak frequency could give useful clues to detect anomalies of MOV.

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확장칼만필터를 이용한 무인잠수정의 3차원 위치평가 (3-D Localization of an Autonomous Underwater Vehicle Using Extended Kalman Filter)

  • 임종환;강철웅
    • 한국정밀공학회지
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    • 제21권7호
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    • pp.130-135
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    • 2004
  • This paper presents a 3-D localization of an autonomous underwater vehicle(AUV). Conventional methods of localization, such as LBL or SBL, require additional beacon systems, which reduces the flexibility and availability of the AUV We use a digital compass, a pressure sensor, a clinometer and ultrasonic sensors for localization. From the orientation and velocity information, a priori position of the AUV is estimated based on the dead reckoning. With the aid of extended Kalman filter algorithm, a posteriori position of the AUV is estimated by using the distance between the AUV and a mother ship on the surface of the water together with the water depth information from the pressure sensor. Simulation results show the possibility of practical application of the method to autonomous navigation of the AUV.