• 제목/요약/키워드: parameter detection

검색결과 823건 처리시간 0.024초

이분산 시계열 모형에서 모수의 변화에 대한 모니터링 절차의 점근 성질 (Asymptotic properties of monitoring procedure for parameter change in heteroscedastic time series models)

  • 김수택;오해준
    • 응용통계연구
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    • 제33권4호
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    • pp.467-482
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    • 2020
  • 본 논문은 이분산성을 갖는 위치-척도 시계열 모형에서 모수의 변화에 대한 모니터링 절차를 연구한다. 모니터링 절차에서 수정된 잔차의 누적합을 이용한 탐지기를 소개하고 귀무가설과 대립가설 하에서 각각 모니터링 절차에 대한 점근적 성질을 규명한다. 그리고 모의실험과 사례 분석을 통하여 제안한 모니터링 방법의 성능이 우수함을 확인한다.

유사측도를 이용한 무인기의 고장진단 및 검출 (Fault Detection and Identification of Uninhabited Aerial Vehicle using Similarity Measure)

  • 박욱제;이상혁
    • 한국항공운항학회지
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    • 제19권2호
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    • pp.16-22
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    • 2011
  • It is recognized that the control surface fault is detected by monitoring the value of the coefficients due to the control surface deviation. It is found out the control surface stuck position by comparing the trim value with the reference value. To detect and isolate the fault, two mixed methods apply to the real-time parameter estimation and similarity measure. If the scatter of aerodynamic coefficients for the fault and normal are closing nearly, fault decision is difficult. Applying similarity measure to decide for fault or not, it makes a clear and easy distinction between fault and normal. Low power processor is applied to the real-time parameter estimator and computation of similarity measure.

회귀분석을 이용한 ITO 코팅유리기판의 표면균일도와 운전변수의 상관관계 분석 (Relationship between Working Parameter and Surface Nniformity of ITO coated Glass Substrate using Regression Analysis)

  • 김면희;이상룡;이태영;배준영
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1353-1356
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    • 2004
  • In recent year, OLED(organic light emitted display) is used as the next generation device of FPD. OLED have been replacing the flat panel display device such as LCD, STN-LCD and TFT because this device is more efficient, economic and simple than those FPD devices, and this need not backlight system for visualization. The performance and efficiency of OLED is related with surface defect of ITO coated glass substrate. The typical surface defect of glass substrate is nonuniformity and bad surface roughness. ITO coated glass substrate is destroied for inspection about surface roughness and non-uniformity. Generally detection of the defects in the surface for ITO coated glass substrate is dependent on operator's experience. In this research, relationship between working parameter and surface non-uniformity is studied using regression analysis.

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RIO-DC Buffer Design for Core Routers in DiffServ Assured Services

  • Hur, Kyeong
    • Journal of information and communication convergence engineering
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    • 제9권5호
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    • pp.539-544
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    • 2011
  • In this paper, a parameter optimization method of RIO-DC (RED (Random Early Detection) with In and Out-De-Coupled Queues) scheme for Assured Service (AS) in Differentiated Services (DiffServ) is proposed. In order to optimize QoS (Quality of Service) performance of the RIO-DC policy for AS in terms of maximum tolerable latency, link utilization, fairness, etc., we should design router nodes with proper RIO-DC operating parameter values. Therefore, we propose a RIO-DC configuration method and the admission control criterion, considering the allocated bandwidth to each subclass and the corresponding buffer size, to increase throughput for In-profile traffic and link utilization. Simulation results show that RIO-DC with the proposed parameter values guarantees QoS performance comparable with the RIO scheme and it improves fairness between AS flows remarkably.

An Intelligent Fault Detection and Service Restoration Scheme for Ungrounded Distribution Systems

  • Yu, Fei;Kim, Tae-Wan;Lim, Il-Hyung;Choi, Myeon-Song;Lee, Seung-Jae;Lim, Sung-Il;Lee, Sung-Woo;Ha, Bok-Nam
    • Journal of Electrical Engineering and Technology
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    • 제3권3호
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    • pp.331-336
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    • 2008
  • Electric load components have different characteristics according to the variation of voltage and frequency. This paper presents the load modeling of an electric locomotive by the parameter identification method. The proposed method for load modeling is very simple and easy for application. The proposed load model of the electric locomotive is represented by the combination of the loads that have static and dynamic characteristics. This load modeling is applied to the KTX in Korea to verify the effectiveness of the proposed method. The results of proposed load modeling by the parameter identification follow the field measurements very exactly.

Damage detection from the variation of parameter matrices estimated by incomplete FRF data

  • Rahmatalla, Salam;Eun, Hee-Chang;Lee, Eun-Taik
    • Smart Structures and Systems
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    • 제9권1호
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    • pp.55-70
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    • 2012
  • It is not easy to experimentally obtain the FRF (Frequency Response Function) matrix corresponding to a full set of DOFs (degrees of freedom) for a dynamic system. Utilizing FRF data measured at specific positions, with DOFs less than that of the system, as constraints to describe a damaged system, this study identifies parameter matrices such as mass, stiffness and damping matrices of the system, and provides a damage identification method from their variations. The proposed parameter identification method is compared to Lee and Kim's method and Fritzen's method. The validity of the proposed damage identification method is illustrated in a simple dynamic system.

잡음음성에서의 음성 활성화 구간 검출 방법 (Speech Active Interval Detection Method in Noisy Speech)

  • 이광석;추연규;김현덕
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2008년도 추계종합학술대회 B
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    • pp.779-782
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    • 2008
  • 음성통신 및 음성인식에 있어서 잡음이 섞인 음성으로부터 음성의 활성화 구간의 검출은 대단히 중요한 과정으로 알려져 있다. 따라서 본 연구에서는 잡음음성으로부터 음성의 활성화 구간을 검출하기 위하여 스펙트럴 엔트로피와 복합으로 구성하는 특징 파라미터를 제안하고 에너지를 기반으로 음성 활성화 구간을 검출하는 방식과 성능 비교 실험을 행하였다. 실험결과, 노이즈 환경에서 다른 파라미터에 비하여 제안한 파라미터에 의한 음성 활성화 구간 검출의 성능이 우수함을 확인할 수 있었다.

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물체지향 부화화에서 계층적 구조를 이용한 결합형 변환 파라미터 추정 기법에 의한 움직임 검출 및 보상 (Motion detection and compensation in object-oriented coding based on combined mapping parameter estimation using hierarchical structure)

  • 이창범;김준식;박래홍
    • 전자공학회논문지A
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    • 제33A권3호
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    • pp.163-175
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    • 1996
  • This paper invetigates estimation methods of mapping parameters in object-oriented coding. In this paper, we propose a fast parameter estimation method with its performance similar to that of the conventional methods. We employ hierarchical structure in difference images to redcue the computational complexity and also combine conventional six- and eight-mapping parameter estimation methods to compensate for the performance degradation caused by employment of hierarchical structure. Computer simulation shows that the proposed mehtod gives results similar to conventional methods with greatly reduced computational complexity.

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다 해상도 기법에 의한 Hough 변환에 관한 연구 (A study on the Hough Transform by using Multi-Resolution technique)

  • 김한영;윤세진;우동민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2234-2236
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    • 1998
  • In this paper, we propose a new algorithm based on multi-resolution application of the parameter space to the Hough transform technique. The existing Hough transform technique employs mapping of fixed parameter space in order to extract straight lines from image. One of the difficulties of the existing Hough transform technique lies in the detection of multiple adjacent lines for only one line. Increasing the parameter space from the low level resolution to the high level resolution, our algorithm detects straight line in a stable and efficient fashion. Experimental results are included to verity the performance of proposed algorithm.

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Structural detection of variation in Poisson's ratio: Monitoring system for zigzag double walled carbon nanotubes

  • Hussain, Muzamal;Asghar, Sehar;Ayed, Hamdi;Khadimallah, Mohamed A.;Alshoaibi, Adil;Tounsi, Abdelouahed
    • Advances in nano research
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    • 제12권4호
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    • pp.345-352
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    • 2022
  • In this paper, natural frequency curves are presented for three specific end supports considering distinct values of nonlocal parameter. The vibrational behavior of zigzag double walled carbon nanotubes is investigated using wave propagation with nonlocal effect. Frequency spectra of zigzag (12, 0) double walled carbon nanotubes have been analyzed with proposed model. Effects of nonlocal parameters have been fully investigated on the natural frequency against against variation of Poisson's ratio. A slow increase in frequencies against variation of Poisson's ratio also indicates insensitivity of it for suggested nonlocal model. Moreover, decrease in frequencies with increase in nonlocal parameter authenticates the applicability of nonlocal Love shell model. Also the frequency curves for C-F are lower throughout the computation than that of C-C curves.