• Transactions on Control, Automation and Systems Engineering
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• 제2권4호
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• pp.228-234
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• 2000

The aim of the work is to present a new method of estimating the existence of a mass unbalance and mass unbalance under a crack on a rotating shaft. This is an advanced new method for the detection of a mass unbalance and a new way to estimate the position of it under crack influence. As the first step, the shaft is physically modelled with a finite element method and the dynamic mathematical model is derived by using the Hamilton principle; thus, the system is represented by various subsystems. The equation of motion of the shaft with a mass unbalance and a crack are established by adapting the local mass unbalance and the stiffness change. this is a reference system for the given system. Based on a model for transient behavior induced from vabrations measured at the bearings, an elementary Estimator is designed to detect mass unblance on the shaft. Using the Estimator, a bank of the Estimator is established to estimate the estimate the position of the mass unbalance and arranged at a certain location on the shaft. The informations for the given system are the measurements of bearing displacements and velocity.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.286-293
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• 1999

A new control scheme using a torsional torque estimator based on a neural network is proposed and investigated for improving control characteristics of the high-performance motion control system. This control method presents better performance in the corresponding speed vibration response, compared with the disturbance observer-based control method. This result comes from the fact that the proposed neural network estimator keeps the self-learning capability, whereas the disturbance observer-based torque estimator with low pass filter should dbjust the time constant of the adopted filter according to the natural resonance frequency detemined by considering the system parameters varied. The simulation results shows the validity of the proposed control scheme.

• 전자공학회논문지C
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• 제34C권10호
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• pp.36-42
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• 1997

In the whole world, the research about the VLSI implementation of motion estimation algorithm is progressed to actively full (brute force) search algorithm research with the development of systolic array possible to parallel and pipeline processing. But, because of processing time's limit in a field to handle a huge data quantily such as a high definition television, many problems are happened to full search algorithm. In the paper, as a fast processing to using parallel scheme for the serial input image data, motion estimator of systolic array structure verifying that processing time is improved in contrast to the conventional full search algorithm.

• 한국정보통신학회논문지
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• 제12권10호
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• pp.1845-1852
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• 2008

인터 예측의 핵심 요소는 ME와 MC이다. ME는 SAD(Sum of Absolute Difference)와 같은 정합기준을 사용하는 것뿐만 아니라 비트스트림의 최종 비트수에 따라서 최적의 움직임 벡터를 찾는다. 인터 예측부호화는 고화질의 실시간 비디오 응용에 있어서 언제나 주된 병목을 초래한다. 따라서 실시간 비디오 응용에서는 인터 예측을 수행하는 고속의 전용 하드웨어를 필요로 한다. 본 논문에서는 H.264/AVC의 움직임 추정기를 연구하였다. 설계된 움직임 추정기는 2-D 시스토릭 배열 기반으로 기본 처리기 요소를 병렬로 연결하여 SAD 값을 빠르게 계산한다. 참조데이터를 상위영역과 하위영역으로 나누어 각각의 연결선을 두고 입력 시퀀스를 조절하여 파이프라인 중지 없이 연속적인 연산을 수행한다. 데이터 재사용 기법을 통하여 메모리 엑세스를 줄였고 특별한 지연 없이 최소의 SAD를 갖는 파티션을 찾아내어 움직임 벡터를 생성하게 하였다. 설계된 움직임 추정기는 가변 블록 크기를 지원하며 하나의 매크로블록의 연산을 하는데 328 사이클이 소요된다. 논문 [6]이 로컬메모리를 사용하는 것과 달리, 본 논문은 로컬메모리를 사용하지 않는다.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.176-184
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• 2001

The VDC(Vehicle Dynamics Control) is a control system whose target is to improve vehicle stability under critical motion. The system has a good potential of becoming a standard active safety unit in passenger vehicles since it can be implemented on top of the ABS/TCS system with little extra cost. This, however, is possible only when the signals that the VDC system demands can be obtained with sufficient accuracy. In this research, estimators for the road friction coefficient and body sideslip angle have been designed. The two variables have great influence upon performance of the VDC system but not directly measurable. For the estimator design, the Newton method and the nonlinear observer theory have been exploited. The performance of the estimator have been verified via simulations on critical driving conditions.

• Journal of the Korean Statistical Society
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• 제26권1호
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• pp.117-130
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• 1997

We study the asymptotic behavior of the maximum partial likelihood estimator in the Cox proportional hazards model in the presence of nuisance parameters when the entry of patients is staggered. When entry of patients is simultaneous and there is only one regression parameter in the Cox model, the efficient score process of the partial likelihood is martingale and converges weakly to a time-chnaged Brownian motion. Our problem is to get a similar result in the presence of nuisance parameters when entry of patient is staggered.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.403-406
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• 1999

Among the compression methods of moving picture information, a motion estimation method is used to remove time-repeating. The Block Matching Algorithm in motion estimation methods is the commonest one. In recent days, it is required the more advanced high quality in many image processing fields, for example HDTV, etc. Therefore, we have to accomplish not by means of Partial Search Algorithm, but by means of Full Search Algorithm in Block Matching Algorithm. In this paper, it is suggested a structure that reduce total calculation quantity and size, because the structure using Bit Plane select and use only 3bit of 8bit luminance signal.

• Journal of the Korean Statistical Society
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• 제34권4호
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• pp.281-295
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• 2005

We investigate the rate of convergence of the distribution of the maximum likelihood estimator (MLE) of an unknown parameter in the drift coefficient of a stochastic process described by a linear stochastic differential equation driven by a fractional Brownian motion (fBm). As a special case, we obtain the rate of convergence for the case of the fractional Ornstein- Uhlenbeck type process studied recently by Kleptsyna and Le Breton (2002).

• Communications for Statistical Applications and Methods
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• 제22권3호
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• pp.295-304
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• 2015

This paper considers the problem of estimation of the Hurst parameter H ${\in}$ (1/2, 1) from longitudinal data with the error term of a fractional Brownian motion with Hurst parameter H that gives the amount of the long memory of its increment. We provide a new estimator of Hurst parameter H using a two scale sampling method based on $A{\ddot{i}}t$-Sahalia and Jacod (2009). Asymptotic behaviors (consistent and central limit theorem) of the proposed estimator will be investigated. For the proof of a central limit theorem, we use recent results on necessary and sufficient conditions for multi-dimensional vectors of multiple stochastic integrals to converges in distribution to multivariate normal distribution studied by Nourdin et al. (2010), Nualart and Ortiz-Latorre (2008), and Peccati and Tudor (2005).

• 한국콘텐츠학회논문지
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• 제9권2호
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• pp.1-9
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• 2009

본 논문은 H.264/AVC 부호화기의 실시간 동영상 부호화를 위한 하드웨어 구현과정 중 파이프라인 구조의 병렬 처리로 인한 데이터 부재문제의 해결방안을 제시하였다. 참조 소프트웨어(JM)의 움직임 추정 연산은 순차적인 처리가 가능하기 때문에 모든 데이터가 유효하지만, 파이프라인 구조로 하드웨어를 구현시 데이터가 병렬적으로 처리되므로 이전데이터가 유효하지 않은 경우가 발생한다. 본 논문에서는 MVp 연산시의 부재되는 데이터 문제를 해결하였다. 제안된 방법은 유효하지 않은 주변블록의 데이터(MV)로 인한 화질저하를 최소화하기 위하여 유효하지 않은 MV를 대신하여, 정수화소 움직임벡터, MVp(Motion Vector Predictor), MVcol(Motion vector of the Co-located block)을 사용하는 방법이다. BDPSNR로 실험 결과 같은 주제로 이전에 연구된 Huang[7]의 실험결과에 비하여 최대 QCIF영상에서 0.555dB, CIF 영상에서 0.834dB의 성능향상을 나타내고 있다.