• 대한전기학회논문지
• /
• 제39권2호
• /
• pp.210-217
• /
• 1990

For the failure detection of dynamic systems, processing the residuals from the observer of the estimator is the most general method. A failure detection method which use an adaptive predictor to separate the effect of sensor failure from the additive noise in the residuals of a Kalman filter that is employed as an estimator of a dynamic system is addressed here. In the method, the property of the residuals of an optimal Kalman estimator is exploited. The simulation results of this method shows that the proposed method is superior to the sequential probability ratio test for a small failure magnitude.

• 디지털산업정보학회논문지
• /
• 제10권4호
• /
• pp.71-78
• /
• 2014

Method a target estimation in spatial are mobile wireless communication using network cell and GPS. It have much error that mobile wireless communication depend on cell size. GPS method can't find a target in shadow and inner area. In this paper, we estimate a target as direction of arrival method using adaptive array antenna system. Adaptive array antenna system can obtain desired signal to remove other signal This paper studied digital beamforming method in order to estimation a target. Proposed method is modified optimum weight and antenna error correction to estimation an optimal receive signal. Digital beamforming method decided a signal phase and amplitude from received signal on array antenna element. But if it is not to do error correction of received signal, system performance have decreased. Firstly, we proposed modified optimum weight in order to finding desired target. Secondly, we are error correction of antenna incident signals by optimal weight before digital beamforming method. Thirdly, throughly simulation, we showed that system performance of proposed method compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

• 디지털산업정보학회논문지
• /
• 제10권4호
• /
• pp.63-70
• /
• 2014

Method a target estimation in spatial are mobile wireless communication using network cell and GPS. It have much error that mobile wireless communication depend on cell size. GPS method can't find a target in shadow and inner area. In this paper, we estimate a target as direction of arrival method using adaptive array antenna system. Adaptive array antenna system can obtain desired signal to remove other signal This paper studied digital beamforming method in order to estimation a target. Proposed method is modified optimum weight and antenna error correction to estimation an optimal receive signal. Digital beamforming method decided a signal phase and amplitude from received signal on array antenna element. But if it is not to do error correction of received signal, system performance have decreased. Firstly, we proposed modified optimum weight in order to finding desired target. Secondly, we are error correction of antenna incident signals by optimal weight before digital beamforming method. Thirdly, throughly simulation, we showed that system performance of proposed method compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

• 대한기계학회논문집A
• /
• 제21권7호
• /
• pp.1030-1041
• /
• 1997

The control model in the tandem cold rolling mill consists of many mathematical theories and is used to calculate the reference values such as the roll gap and the rolling speed for good operation of rolling mill. But, the control model used presently has a problem causing inaccurate prediction of the rolling force. By the parameter identification, it was found that the main factor causing inaccurate prediction of the rolling force was incorrect modeling of the friction coefficient and the flow stress. To get rid of the erroneous factor new adaptive schemes are suggested in this work. Those are a long-time adaptation by the iterative least-square method and a short-time adaptation by the recursive weighted least-square method respectively. The new equations for the friction coefficient and the flow stress are derived by applying the suggested adaptive algorithms. Through the on-line test in an actual mill, it is proved that the rolling force predicted by the new equations is more accurate than the one by the existing equations ever used.

• 대한기계학회논문집A
• /
• 제24권8호
• /
• pp.2100-2107
• /
• 2000

The wavelet theory is relatively a new development and now acquires popularity and much interest in many areas including mathematics and engineering. This work presents an adaptive wavelet method for a numerical solution of partial differential equations in a collocation sense. Due to the multi-resolution nature of wavelets, an adaptive strategy can be easily realized it is easy to add or delete the wavelet coefficients as resolution levels progress. Typical wavelet-collocation methods use interpolating wavelets having no vanishing moment, but we propose a new wavelet-collocation method on modified interpolating wavelets having 2 vanishing moments. The use of the modified interpolating wavelets obtained by the lifting scheme requires a smaller number of wavelet coefficients as well as a smaller condition number of system matrices. The latter property makes a preconditioned conjugate gradient solver more useful for efficient analysis.

• 대한전자공학회논문지SP
• /
• 제38권1호
• /
• pp.19-32
• /
• 2001

본 논문에서는 영상의 밝기 값을 마치 3차원 지형과 같은 개념으로 간주하여 여기에 물이 흐르는 개념을 적용하여 국부 적응 (locally adaptive) thresholding 방법을 제안하였다. 문자를 추출해내기 위해 제안한 방법에서는 지형 표면에 물을 붓는 과정을 수행하였다. 물은 지형의 낮은 곳으로 흐르게 되어 계곡 (valley)에 쌓인다. 이때 문자와 배경으로 구성된 문서영상에서 쌓인 물의 양을 기준으로 두 개의 영역을 구분을 하였다. 제안한 water flow model의 개념을 적용한 threholding 방법은 국부 적응 thresholding의 특성을 나타낸다. 합성 영상과 실제 영상을 이용하여 전산 모의 실험을 수행함으로써 제안한 방법이 문서 영상을 효과적으로 이진화할 수 있음을 보였다.

• 대한기계학회논문집A
• /
• 제21권2호
• /
• pp.281-287
• /
• 1997

In the conventional inverse modeling method for on-line modeling of the secondary path transfer function, the signal to noise ratio between the arbitrary random signal and the plant noise have to keep at -10 - -20 dB. For these reasons, the modeling can't be exactly implemented by the conventional method alone and the convergence time for modeling becomes too long. In this study, by combining the conventional inverse modeling method with an adaptive line enhancer, or with an adaptive noise canceller, a rigorous transfer functions of secondary path modeling and the control of a primary noise have been implemented simultaneously.

• 대한산업공학회지
• /
• 제29권4호
• /
• pp.312-320
• /
• 2003

Recently there is a growing interest in mobile cellular network providing multimedia service. However, the link bandwidth of mobile cellular network is not sufficient enough to provide satisfactory services to users. To overcome this problem, an adaptive framework has been proposed. In this study, we propose a new method of estimating DPR(Degradation Period Ratio) in an adaptive multimedia network where the bandwidth of ongoing call can be dynamically adjusted during its lifetime. DPR is a QoS(Quality of Service) parameter which represents the ratio of allocated bandwidth below a pre-defined target to the whole service time of a call. We improve estimation method of DPR using DTMC(Discrete Time Markov Chain) model by calculate mean degradation period, degradation probability more precisely than in existing studies. Under Threshold CAC(Call Admission Control) algorithm, we present analytically how to guarantee QoS to users and illustrate the method by numerical examples. The proposed method is expected to be used as one of CAC schemes in guaranteeing predefined QoS level of DPR.

• 조명전기설비학회논문지
• /
• 제23권12호
• /
• pp.48-57
• /
• 2009

본 논문에서는 FEM(Finite Element Method)을 이용한 직접구동형 영구자석 풍력발전기의 최적설계를 위해 최신의 최적화 기법인 MADS(Mesh Adaptive Direct Search)를 적용하였으며, 최적설계 목표는 연간 에너지 생산량(Annual Energy Production : AEP)을 최대화 하는 방향으로 선정하였다. 또한, 풍력발전기의 전 운전영역을 고려하기 위해 해당풍속에서의 통계적 확률밀도와 연간 운전시간을 적용하여 연간 최대에너지 생산량을 산정하였다. 아울러, MADS의 최적설계 결과와 병렬분산 컴퓨팅을 결합한 유전 알고리즘(Genetic Algorithm : GA)의 최적설계 결과를 비교하였으며, MADS는 병렬분산 유전알고리즘에 비해 상대적으로 빠른 수렴성을 나타내었다.

• ETRI Journal
• /
• 제35권5호
• /
• pp.900-910
• /
• 2013

Small-screen mobile terminals have difficulty accessing existing Web resources designed for large-screen devices. This paper presents an adaptive transformation method based on webpage semantic features to solve this problem. According to the text density and link density features of the webpages, the webpages are divided into two types: index and content. Our method uses an index-based webpage transformation algorithm and a content-based webpage transformation algorithm. Experiment results demonstrate that our adaptive transformation method is not dependent on specific software and webpage templates, and it is capable of enhancing Web content adaptation on small-screen terminals.