• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.92-98
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• 2012

As the increasing of non-linear load, filter is coming to be high gradually in order to reduce the harmonic which occurs from the power conversion. The maintenance of passive filter is easier than active filter and it has been widely used in the industrial site. This passive filter is connected with condenser and reactor by series and parallel and it is installed at the front of nonlinear load. The breakdown of passive filter occurs frequently at the reactor side rather than capacitor. So the breakdown cause close examination is necessary. In this paper, we analyzed that the electric stress of reactor which is considered magnetization saturation at the passive filter. We confirm that the reduction of harmonics and the electric stress of reactor is influenced by the linear and non-linear element of reactor.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.1-8
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• 2009

Recently, application of non-linear load is gradually increased. Non-linear load produces harmonic components of current during the energy conversion transition. Passive filter is used for reducing of harmonics in the user power systems. This filter, which is composed of capacitor and reactor, frequently get out of order by electrical stress. There are voltage and current increase when capacitor and reactor are applied in the user's filter systems. If increased voltage and current is above stipulated values, they have severely an influences on the life of capacitor and reactor. This paper describes that the voltage and current of capacitor used for filter is within the limits of allowable values, but reactor is beyond the limits and reveals spike voltage. Therefore this phenomenon brings about premature fault of reactor and capacitor.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.413-418
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• 2003

In this paper, a new multirate optimal finite impulse response (FIR) filter is proposed for the signal reconstruction in the nosy filter bank systems. The multirate optimal FIR filter replaces the conventional synthesis filters and the Kalman synthesis filter. First, the generic linear model is derived from the multirate state space model for an autoregressive (AR)input signal. Second, the multirate optimal FIR filter is derived from the multirate generic linear model using the minimum variance criterion. This paper also provides numerical examples and results. The simulation results illustrate that the performance is improved compared with conventional synthesis filters and the proposed filter has advantages over the Kalman synthesis filter.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.860-863
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• 1996

In this paper, we formulate the extended Kalman filter for calibration of gimballed inertial navigation system (GINS) at a pure navigation mode with 1500 ft/sec initial velocity and compare its performance to the linear Kalman filter's by using Monte-Carlo analysis method. It has been shown that estimation performance of the extended Kalman filter is better than that of the linear Kalman filter.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.296-299
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• 2003

This paper shows a novel and simple IIR/FIR QMF(quadrature mirror filter) filter banks, mixed IIR and FIR structure. Here, FIR filters used for phase compensation. In this paper, we introduced analysis and synthesis filter banks, which used FIR linear phase filters and all pass filters. In result, phase response of analysis and synthesis filter banks become approximately linear characteristic. Simultaneously, a liasing distortion can be completely canceled.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.11-12
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• 2002

Accidental overexposures by radiotherapy have gathered attention recently in Japan. The widely publicized accidents have occurred at the government official benefit society hospital and at the hospital affiliated to a medical school. The accident at the government official benefit society hospital occurred when one of two existing accelerators was renewed. A radiotherapy planning system was also introduced at that time. Then treatment planning for the old and the new linear accelerator was performed using the system. There were variations in wedge factors for the 30 degrees wedge filter between the old and the new linear accelerator. That is, the difference in the structure of the wedge filter (30 degrees) resulted in variations of the wedge factors between both accelerators. In order to keep strength, a lead board was backed to the lead wedge filter for the new linear accelerator, whereas the wedge filter for the old one was made of the iron. The X-ray attenuation of the iron wedge filter is smaller than that of the lead wedge filter. The basic beam data of the old linear accelerator, however, wasn't delivered properly between the user and the maker. Then, the accident took place because the same wedge factor was used for the old and the new linear accelerator. On the other hand, the accident which occurred at the university hospital was brought about by the input mistake in initialization of the computer system when a linear accelerator was introduced. The input mistake was found when the software of the system was updated. If the dose had been measured and confirmed adequately, the accidents could have been prevented in both cases.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.212-218
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• 2013

In this paper, a linear motor piston amplitude estimator using phase lag filter has been implemented. In order to control the cooling capability of a refrigerator or an air conditioner in which liner compressors are applied, the piston speed should be controlled. The piston speed control can be obtained by adjusting the frequency or the stroke of linear motors. The dynamic performance of linear compressors depends on how accurately the stroke or the piston amplitude is estimated. A linear motor piston amplitude estimator using phase lag filter is proposed and the superior performance of our estimator is verified via some simulation studies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.314-324
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• 2018

This paper proposes a linear distributed target tracking filter for multiple unmanned aerial vehicles(UAVs) sharing their passive sensor measurements through communication channels. Different from the conventional nonlinear filtering schemes, the distributed passive target tracking problem is newly formulated within the framework of a linear robust state estimation theory incorporated with a linear uncertain measurement equation including the coordinate transform uncertainty. To effectively cope with the performance degradation due to the coordinate transform uncertainty, a linear consistent robust Kalman filter(CRKF) theory is devised and applied for designing a distributed passive target tracking filter. Through the simulations for typical UAV surveillance mission, the superior performance of the proposed method over the existing schemes of distributed passive target tracking are demonstrated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.152-161
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• 2009

As follow jamming signals in a FHSS system cause malfuctioning in the code tracking circuits using early-late gates, we need a code tracking circuit that is robust against the follow jamming signals. In this paper, we propose a code tracking circuit using a linear clipper-Gaussian filter algorithm to remedy the malfunctioning due to the follow jamming signals in FHSS systems. We investigate the mechanism of the malfunctioning of the code tracking circuit and verify that the proposed linear clipper-Gaussian filter metigates the problem through mathematical analysis and computer simulations.

• Journal of the Korean Mathematical Society
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• v.55 no.5
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• pp.1063-1073
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• 2018

We study the estimation of the drift parameter and the change point obtained through a Kalman-Bucy filter for linear systems with signal driven by a fractional Brownian motion and the observation driven by a Brownian motion.