• Title/Summary/Keyword: Filter

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Design of a wavelet adaptive filter for removal of the baseline wandering (기저선 변동 제거를 위한Wwavelet Adaptive Filter의 설계)

  • 박광리;이경중;윤형로
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.10
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    • pp.80-88
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    • 1997
  • This paper describes a design of a Wavelet Adaptive Filter(WAF) for the removal of the baseline wandering and the minimization of the signal distortion using by wavelet transform and adaptive filter in the ECG signal. WAF consists of two parts. The first part is wavelet transform that decomposes the ECG signal into seven frequency bands using Vaidyanathan and Hoang wavelet. The second part is adaptive filter that uses the signal of seventh low frequency band among the wavelet transformed signals as primary input and a unit impulse sequence as reference input. For the evaluation of the performance of WAF, we used several baseline wandering elimination filters such as commerical standard filter with cutoff frequency of 0.5Hz and general adaptive filter. We made use of MIT/BIH database and real patient data for the evaluation. In conclusion, WAF showed a lower ST segement distortion than standard filter and adaptive filter and has a higher eliminated noise power than standard filter and adaptive filter.

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A General Analysis and Complexity Reduction for the Lattice Transversal Joint Adaptive Filter

  • Yoo, Jae-Ha
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.2035-2038
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    • 2002
  • The necessity of the filter coefficients compensation for the LTJ adaptive filter was explained generally and easily by analyzing it with respect to the time-varying transform domain adaptive filter. And also the reduction method of computational complexity for filter coefficients compensation was proposed and its effectiveness was verified through experiments using artificial and real speech signals. The proposed adaptive filter reduces the computational complexity for filter coefficients compensation by 95%, and when the filter is applied to the acoustic echo canceller with 1000 taps, the total complexity is reduced by 82%

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Unified FIR filter using delta operator (델타 연산자를 이용한 통합형 FIR 필터)

  • 서민상;권오규
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.912-916
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    • 1992
  • In this paper we investigate the connection between the continuous-time FIR(finite impulse response) filter and the corresponding discrtet-time FIR filter with fast sampling. The interconnection is established by formulating the discrete-time case using delta operators which has superior numerical properties in discretizing prcedure. The aim of this paper is to present a unified FIR filter using the .delta.-operator and to show that, as sampling interval .DELYA. aperator to zero, the results of this filter converge to the corresponding continuous-time reuslts, which implies that the unified FIR filter unifies continous-time FIR filter and discrtet-time FIR filter.

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Velocity Matching Algorithm Using Robust H₂Filter (강인 H₂필터를 이용한 속도정합 알고리즘)

  • Yang, Cheol Gwan;Sim, Deok Seon;Park, Chan Guk
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.4
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    • pp.363-363
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    • 2001
  • We study on the velocity matching algorithm for transfer alignment of inertial navigation system(INS) using a robust H₂ filter. We suggest an uncertainty model and a discrete robust H₂filter for INS and apply the suggested robust H₂ filter to the uncertainty model. The discrete robust H₂filter is shown by simulation to have better performance time and accuracy than Kalman filter.

PERFECT AND CONCRETE FILTERS OF WFI-ALGEBRAS

  • Jun, Young-Bae
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.4
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    • pp.691-699
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    • 2007
  • The notion of perfect filters and concrete filters in WFI-algebras is introduced, and several properties are investigated. Relations between a filter, a perfect filter and a concrete filter are given, and characterizations of a perfect filter and a concrete filter are provided. An extension property for a concrete filter and a perfect filter is established.

The Study on Characteristics of Collected Filter as Analysis of Carbon in Airborne Particulate Matters by Elemental Analyzer (원소분석기를 사용한 부유입자상물질중의 탄소성분 분석시 포집여지의 특성에 관한 연구)

  • 황경철;조기철;최종욱
    • Journal of environmental and Sanitary engineering
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    • v.10 no.2
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    • pp.67-73
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    • 1995
  • In order to study of characteristics of collected filter as analysis of carbon in airborne particulate matters by Elemental Analyzer, quartz fiber filter and glass fiber filter were used. The results are followed as; There was no difference of confidence in collection rate of airborne particulate matters between quartz fiber filter and glass fiber filter. Airborne particulate matters were collected on both filters evenly and the use of quartz fiber filter is better than glass fiber filter as analysis of carbon by thermal method.

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Design of Filter Cut-off Technology based on Directshow (다이렉트쇼 기반의 필터차단기술 설계)

  • Kim, Dae-Jin;Choi, Hong-Sub
    • The Journal of the Korea Contents Association
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    • v.9 no.12
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    • pp.77-85
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    • 2009
  • As the multimedia technology has become in popular, many software packages that are for using those multimedia contents have also been developed. Directshow is a media framework which makes the development of such multimedia software simple, quick and regular process. In the Directshow, data are processed through the connections between filters. In general, Filtergraph is utilized to be set as 'Intelligent Connection' for filter connection. However, when we use this 'Intelligent Connection' option, they can show non-expected results or fail to connect with filter's pins together. So in this paper, we propose non-necessary filter cut-off method for connecting only just wanted filters. There are two methods such as inner filter cut-off method and outer filter one. The inner filter cut-off method is good at connection's compatibility and able to quickly connect with each other filter. But in the outer filter cut-off method, filter source is not necessary and connection is exactly done with other filter. In the end, we propose Directshow based filter cut-off model which compose of wanted filter connection and minimize error probability, through mixing up the advantages of two filter cut-off methods.

Filter- and Denuder-Based Organic Carbon Correction for Positive Sampling Artifacts

  • Hwang, InJo;Na, Kwangsam
    • Asian Journal of Atmospheric Environment
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    • v.11 no.2
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    • pp.107-113
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    • 2017
  • This study describes (1) the impact of positive sampling artifacts caused by not only a filter-based sampling, but also a denuder-based sampling in the determination of particle-phase organic carbon (POC), (2) the effect of sample flow rate on positive artifacts, and (3) an optimum flow rate that provides a minimized negative sampling artifact for the denuder-based sampling method. To achieve the goals of this study, four different sampling media combinations were employed: (1) Quartz filter-alone (Q-alone), (2) quartz filter behind quartz-fiber filter (QBQ), (3) quartz filter and quartz filter behind Teflon filter (Q-QBT), and (4) quartz filter behind carbon-based denuder (Denuder-Q). The measurement of ambient POC was carried out in an urban area. In addition, to determine gas-phase OC (GOC) removal efficiency of the denuder, a Teflon filter and a quartz filter were deployed upstream and downstream of the denuder, respectively with varying sample flow rates: 5, 10, 20, and 30 LPM. It was found that Q-alone sampling configuration showed a higher POC than QBQ, Q-QBT, and Denuder-Q by 12%, 28%, and 23%, respectively at a sample flow rate of 20 LPM due to no correction for positive artifact caused by adsorption of GOC onto the filter. A lower quantity of GOC was collected from the backup quartz filter on QBQ than that from Q-QBT. This was because GOC was not in equilibrium with that adsorbed on the front quartz filter of QBQ during the sampling period. It is observed that the loss of particle number and mass across the denuder increases with decreasing sample flow rate. The contribution o f positive arti facts to POC decreased with increasing sample flow rate, showing 29%, 25%, and 22% for 10, 20, and 30 LPM, respectively. The 20 LPM turns out to be the optimum sample flow rate for both filter and denuder-based POC sampling.

Assessment of Bacteria Removal Using Silver Ion Absorbed Ceramic Filter

  • Kim, Woo-Hang;Smith, James
    • Journal of Environmental Science International
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    • v.21 no.8
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    • pp.901-907
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    • 2012
  • The objective of this study was to evaluate bacteria removal ability of the metallic silver which was baked silver ion impregnated ceramic filter at heating condition. Silver leaking from baked ceramic filter was tested to sustain bacteria removal for a long time. Silver impregnated ceramic filter could remove E. coli completely at $10^{12}$ MPN/100ml to $10^{13}$ MPN/100ml of influent. However, ceramic filter without silver did not remove E. coli completely under the same condition. After baking, the silver impregnated ceramic filter almost didn't leak out the silver ion from filter. Photo of TEM (Transmission Electron Microscopy) showed that absorbed silver ions remained in ceramic filter after baking process and most of silver were less than 10 nm. According to the increase in the amount of silver in the ceramic filter, removal efficiencies of E. coli were increased but turbidity removal was decreased. It can be accounted that increased removal efficiency of E. coli was from disinfection of silver that is in the ceramic filter. Simulated concentrations of bacteria agree well with the observed experimental effluent concentration data. Moreover, first-order decay coefficients increased to 0.0034/min after silver was added in the ceramic filter. Increase of first-order decay coefficient proves that silver-added ceramic filter can remove bacteria easily.

Performance Evaluation of the Modified Interacting Multiple Model Filter Using 3-D Maneuvering Target (3차원 기동표적을 사용한 수정된 상호작용 다중모델필터의 성능 분석)

  • Park, Sung-Lin;Kim, Ki-Cheol;Kim, Yong-shik;Hong, Keum-Shik
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.5
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    • pp.445-453
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    • 2001
  • The multiple targets tracking problem has been one of the main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimen-sion filter, input estimation filter, interacting multiple model(IMM) filter, dederated variable dimension filter with input estimation, etc., have proposed to address the tracking and sensor fusion issues. In this pa- per, two existing tracking algorithm, i.e, the IMM filter and the variable dimension filter with input estima-tion(VDIE), are combined for the purpose of improving the tracking performance for maneuvering targets. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns, i.e., waver, pop-up, and high-diver motions, are defined and are applied to the modified IMM filter as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMM filter than the standard IMM filter are demonstrated though computer simulations.

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