• 제목/요약/키워드: Observation Error

검색결과 710건 처리시간 0.029초

Nonlinear Observers for Perspective Time-Varying Linear Systems

  • Itoh, Masahiko
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.83.5-83
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    • 2002
  • Perspective dynamical systems arise in machine vision, in which only perspective observation is available, and the essential problem is to estimate the state and /or unknown parameters for a moving rigid body based on the observed information. This paper proposes and studies a Luenberger-type observer for perspective tim e-varying linear systems. In particular, assuming a given perspective time-varying linear system to be Lyapunov stable and to satisfy some sort of observability condition, it is shown that the estimation error converges exponentially to zero. Finally, a simple numerical exam pie is presented to illustrate the result obtained.

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WALSH 함수에 의한 쌍일차계의 관측자설계에 관한 연구 (A study on the observer design of bilinear system via walsh function)

  • 안두수;김종부
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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    • pp.115-119
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    • 1987
  • In this paper the observer design problem in bilinear systems is studied using the Walsh functions as approximating set of functions to find a finite series expansion of the state of bilinear system. A classical Liapnove method, to finding a class of observer feedback matrix, is applied to ensure uniform asymptotic stability of the observation error dynamics. An algorithm is derived for observer state eq. via Walsh function. The basic objective is to develop a computational algorithm for the determination of the coefficients in the expansion. This approach technique gives satisfactory result as well provides precise and effective method for the bilinear observer design problem.

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Perceptron 알고리즘을 이용한 가중 순서 통게 필터의 설계 (A Design Method for Weighted Order Statistic Filters Based on the Perceotron Algorithm)

  • 정병장;이용훈
    • 전자공학회논문지B
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    • 제30B권6호
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    • pp.1-6
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    • 1993
  • In this paper, we observe that the design of optimal weighted order statistic(WOS) filters minimizing the mean absolute error criterion can be though of as a two-class linear classification problem. Based on this observation, the perceptron algorithm is applied to design WOS filters. It is shown, through experiments, that the perceptron algorithm can find optimal or near optimal WOS filters in practical situations.

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표면 부착형 영구자석 전동기의 역기전력 관측 오차 분석 및 센서리스 기동 전략 (Analysis of Back-EMF Observation Error and Starting Strategy for Sensorless Drive of PMSM)

  • 김재석;설승기
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2013년도 전력전자학술대회 논문집
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    • pp.271-272
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    • 2013
  • 본 논문에서는 표면부착형 영구자석 전동기의 역기전력을 이용한 센서리스 운전에서 제정수 오차 및 데드타임 등에 의한 입력 전압 오차에 따른 역기전력 관측오차를 분석 하였고 그 결과를 토대로 전동기의 센서리스 기동을 위한 전략을 제시 하였다. 고의적으로 저항을 작게 추정하면 기동 특성이 개선됨을 확인하였다.

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Extraction of GCP from nighttime AVHRR image

  • Tamba, Sumio;Iikura, Yoshikazu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.770-772
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    • 2003
  • In this paper, to correct the error, we propose a method to estimate a correction data based on observation data obtained from MUBEX campaign. Many heat spots are correspond to industrial area including steel plant, power plant and so on. Heat spot transmits some kinds of thin cloud because it emits large radiance, so that it is possible to extract GCP from the area under the thin cloud.

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Statistical Correction of Numerical Model Forecasts for Typhoon Tracks

  • Sohn, Keon-Tae
    • Communications for Statistical Applications and Methods
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    • 제12권2호
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    • pp.295-304
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    • 2005
  • This paper concentrates on the prediction of typhoon tracks using the dynamic linear model (DLM) for the statistical correction of the numerical model guidance used in the JMA. The DLM with proposed forecast strategy is applied to reduce their systematic errors using the latest observation. All parameters of the DLM are updated dynamically and backward forecasting is performed to remove the effect of initial values.

Parametric Empirical Bayes Estimation of A Constant Hazard with Right Censored Data

  • Mashayekhi, Mostafa
    • International Journal of Reliability and Applications
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    • 제2권1호
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    • pp.49-56
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    • 2001
  • In this paper we consider empirical Bayes estimation of the hazard rate and survival probabilities with right censored data under the assumption that the hazard function is constant over the period of observation and the prior distribution is gamma. We provide an estimator of the first derivative of the prior moment generating function that converges at each point to the true value in $L_2$ and use it to obtain, easy to compute, asymptotically optimal estimators under the squared error loss function.

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초정밀 단일점 다이아몬드 터닝을 이용한 비구면 금속 부반사경 가공 (Ultra-precision single point diamond turning (SPDT) on an aspheric metal secondary mirror)

  • Kim, E. D.;H. S. Yang;Kim, G-H.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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    • pp.96-97
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    • 2001
  • A 110 mm diameter aspheric metal secondary mirror for a test model of an earth observation satellite camera was fabricated by ultra-precision single point diamond turning (SPDT) . Without a conventional polishing process, the surface texture of R$\sub$a/=2.8 nm, and the form error of R$\sub$a/=0.05 λ has been stably achieved In a laboratory condition. (omitted)

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UMTS 단말기 모뎀의 초기 셀 탐색 파라미터의 영향에 대한 연구 (A Study on Initial Cell Search Parameters in UMTS Terminal Modem)

  • 류동렬;김용석;옥광만;최형진
    • 한국통신학회논문지
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    • 제28권5A호
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    • pp.267-275
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    • 2003
  • UMTS는 1) 슬롯 동기 획득, 2)코드그룹 및 프레임 동기 획득, 3) 코드 식별 과정으로 구성된 초기 셀 탐색방법을 사용한다. 단말 모뎀의 초기 셀 포착 성능은 탐색기의 관찰 구간과 임계값 등의 탐색 파라미터에 의하여 크게 영향을 받는다. 본 논문의 목적은 최소 평균 포착 시간을 구하기 위한 단계별 관찰 구간과 임계값을 구하는데 있다. 본 논문에서는 3단계 탐색과정을 상태 다이어그램을 통하여 모델링하고 이로부터 단계별 평균 검출 시간과 전체 평균 포착 시간을 유도한다. 또한 초기 발진기 오차를 고려한 셀 탐색 알고리즘을 제시하고, 모의 실험결과와 유도한 단계별 평균 검출 시간을 이용하여 적절한 각 단계별 검출 시간을 설정한다. 각 단계의 최적 임계값은 유도된 전체 평균 포착 시간으로부터 결정될 수 있으며, 결정된 파라미터를 이용하여 다중경로 페이딩 채널에서 500ms이내의 성능을 얻을 수 있었다.

임해지역의 개발이 기상장에 미치는 영향예측 (Numerical Simulation of Effect on Atmospheric Flow Field by Development of Coastal Area)

  • 이상득;문태룡
    • 한국환경과학회지
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    • 제15권10호
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    • pp.919-928
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    • 2006
  • The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain lot the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values, Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is veil accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center. Temperature after development was high $0.55\sim0.67^{\circ}C$ in the 14 hoots, also was tend to appear lowly $0.10\sim0.22^{\circ}C$ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.