• Title/Summary/Keyword: 적응적 필터링

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Comparison of Recommendation Techniques for Web-based Design Personalization Service (웹기반 개인화 디자인 서비스를 위한 효과적인 추천 기법의 비교 연구)

  • Seo, Jong-Hwan;Byun, Jae-Hyung;Lee, Kun-Pyo
    • Science of Emotion and Sensibility
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    • v.9 no.spc3
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    • pp.179-185
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    • 2006
  • This study examines and compares various recommendation techniques which have been used successfully in other fields and seeks for opportunity to improve design personalization service more effectively. Throughout the literature study, several major recommendation techniques were identified, namely 'contents-based filtering', 'collaborative filtering', and 'demographic filtering'. In order for finding out relative advantages and disadvantages, a case study was carried out by applying different techniques. The result showed that in general, demographic filtering was evaluated least efficient among the techniques. Content-based filtering showed the best efficiency among them. Another significant finding was that the collaborative filtering had a better efficiency as the number of test subjects is increased. In conclusion, we suggest that design recommendation services can be improved by applying contents-based or collaborative filtering for better efficiency of recommendation. And, if the number of test subjects is large enough, it may be possible to remarkably improve the efficiency of design recommendation services by using collaborative filtering.

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Multiplication Free Adaptive Digital Filter (승산을 요하지 않는 적응 디지탈 필터)

  • Park, Tae-Ho;Cha, Il-Hwan;Yun, Dae-Hui
    • The Journal of the Acoustical Society of Korea
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    • v.6 no.2
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    • pp.15-18
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    • 1987
  • Multiplication free adaptive digital filtering algorithms are discussed. The proposed. The proposed algorithm uses delta modulation digital filter and the relevant filter weights are updated using the SIGN algorithms to realize an adaptive digital filter without multiplication operations. It is shown that the resulting algorithm can be implemented using simple up/down counting operations. The convergence characteristics of the proposed adaptive digital filtering algorithm and .others are investigated for a system identification problem.

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Filtering Motion Vectors using an Adaptive Weight Function (적응적 가중치 함수를 이용한 모션 벡터의 필터링)

  • 장석우;김진욱;이근수;김계영
    • Journal of KIISE:Software and Applications
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    • v.31 no.11
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    • pp.1474-1482
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    • 2004
  • In this paper, we propose an approach for extracting and filtering block motion vectors using an adaptive weight function. We first extract motion vectors from a sequence of images by using size-varibale block matching and then process them by adaptive robust estimation to filter out outliers (motion vectors out of concern). The proposed adaptive robust estimation defines a continuous sigmoid weight function. It then adaptively tunes the sigmoid function to its hard-limit as the residual errors between the model and input data are decreased, so that we can effectively separate non-outliers (motion vectors of concern) from outliers with the finally tuned hard-limit of the weight function. The experimental results show that the suggested approach is very effective in filtering block motion vectors.

Adaptive Inter-layer Filter Selection Mechanism for Improved Scalable Extensions of High Efficiency Video Coding (SHVC) (스케일러블 HEVC 부호화 효율 개선을 위한 계층 간 적응적 필터 선택 알고리즘)

  • Lee, Jong-Hyeok;Kim, Byung-Gyu
    • Journal of Digital Contents Society
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    • v.18 no.1
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    • pp.141-147
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    • 2017
  • Scalable extension of High Efficiency Video Coding (SHVC) standard uses the up-sampled residual data from the base layer to make a residual data in the enhancement layer. This paper describes an efficient algorithm for improving coding gain by using the filtered residual signal of base layer in the Scalable extension of High Efficiency Video Coding (SHVC). The proposed adaptive filter selection mechanism uses the smoothing and sharpening filters to enhance the quality of inter-layer prediction. Based on two filters and the existing up-sampling filter, a rate-distortion (RD)-cost fuction-based competitive scheme is proposed to get better quality of video. Experimental results showed that average BD-rate gains of 1.5%, 2.1%, and 1.7% for Y, U and V components, respectively, were achieved, compared with SHVC reference software 5.0, which is based on HEVC reference model (HM) 13.

Multimedia service based on TPEG information on DMB (DMB 방송에서 TPEG 기반 멀티미디어 서비스)

  • 김영석;정용주;노용만;함영권
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2004.11a
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    • pp.93-96
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    • 2004
  • DMB 방송환경에서 TPEG이라는 새로운 형태의 교통방송 서비스를 제공함에 있어서 기존의 일방적이고 무차별적으로 제공되는 방송환경 하에서 필요로 하지 않는 교통정보를 여과하고, 사용자의 환경과 선택에 맞는 최적의 정보를 제공하기 위하여 TPEG 정보의 필터링 알고리즘을 제안하고, 필터링 된 교통정보의 실시간 유효성을 검사하여 실 시간적으로 교통정보를 갱신하여 DB에 저장하고 필터링 된 교통정보를 바탕으로 소요시간을 계산하여 사용자 환경에 맞게 적응 변환된 멀티미디어 컨텐츠를 제공할 수 있는 방법 및 시스템에 대하여 제안한다.

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A DCT Adaptive Subband Filter Algorithm Using Wavelet Transform (웨이브렛 변환을 이용한 DCT 적응 서브 밴드 필터 알고리즘)

  • Kim, Seon-Woong;Kim, Sung-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.1
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    • pp.46-53
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    • 1996
  • Adaptive LMS algorithm has been used in many application areas due to its low complexity. In this paper input signal is transformed into the subbands with arbitrary bandwidth. In each subbands the dynamic range can be reduced, so that the independent filtering in each subbands has faster convergence rate than the full band system. The DCT transform domain LMS adaptive filtering has the whitening effect of input signal at each bands. This leads the convergence rate to very high speed owing to the decrease of eigen value spread Finally, the filtered signals in each subbands are synthesized for the output signal to have full frequency components. In this procedure wavelet filter bank guarantees the perfect reconstruction of signal without any interspectra interference. In simulation for the case of speech signal added additive white gaussian noise, the suggested algorithm shows better performance than that of conventional NLMS algorithm at high SNR.

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Improved Postprocessing Method for Removing Blocking Artifacts in Block DCT-based Compressed Image (블록 DCT기반 압축 영상의 개선된 블록화현상 제거 후처리 기법)

  • 김재원;조용설;전병우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.6B
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    • pp.784-793
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    • 2001
  • 본 논문에서는 이산 여현변환에 기반으로 한 고압축의 복원된 영상으로 발생하는 블록화 현상을 제거하기 위한 개선된 후처리 기법을 제안한다. 먼저 압축으로부터 복원된 영상에 대하여, 변환 블록단위로 계산된 블록 경계 불연속값을 이용하여 블록화현상 블록과 에지블록을 구별한다. 블록화현상 블록은 다시 블록 경계면의 격차 정도에 따라 적응적으로 블록경계에서 필터링되는 화소 범위를 다르게 하여 필터링하며, 에지 블록은 다시 화소단위로 에지화소 여부를 조사하여, 에지가 아닌 화소만 필터링을 취하여 좀 더 세밀하게 블록화 현상을 제거하는 새로운 방법을 제안한다. 실험 결과를 통하여 제안한 방법이 기존 방법에 비해 시각적으로 향상된 영상을 얻을 수 있음을 입증하였다.

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Spatial Frequency Adaptive Image Restoration Using Wavelet Transform (웨이브릿 변환을 이용한 공간주파수 적응적 영상복원)

  • 우헌배;기현종;정정훈;신정호;백준기
    • Journal of Broadcast Engineering
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    • v.8 no.2
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    • pp.204-208
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    • 2003
  • In this paper, a new matrix vector formulation for a wavelet-based subband decomposition is introduced. This formulation provides a means to compute a regular multi-resolution analysis over many levels of decomposition. With this approach. any single channel linear space-invariant filtering problem can be cast into a multi-channel framework. This decomposition Is applied to the linear space-invariant image restoration problem and propose a frequency-adaptive constrained least squares(CLS) filter. In the proposed filter, we use different parameters adaptively according to subband characteristics. Experimental results are presented for the proposed frequency-adaptive CLS filter These experiments show that if accurate estimates of the subband characteristics are available, the proposed frequency adaptive CLS filter provides significant improvements over the traditional single channel filter.

The Separation of NTSC Signal Components by Using Adaptive Selection Method of Horizontal and Vertical Filters (수평 및 수직 필터의 적응적 선택에 의한 NTSC 칼라영상신호의 성분분리)

  • 권병헌;황병원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.2
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    • pp.211-224
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    • 1994
  • In this paper, a multi-level adaptive intraframe method has been proposed to separate the luminance and chominance components in NTSC composite signal. The control signals are generated by detecting the vertical correlation and transition in the horizontal and diagonal directions. The chrominance component is adaptively processed through vertical and horizontal filters according to the control signals and the luminance component is processed by subtracting the chrominance component from the composite video signal. The several filters have been used at the sampling rate of four times the color subcarrier frequency and computer simulation and SVP(Serial Video Processing) system have been introduced to compare the performance of the conventional methods and that of proposed one.

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Contents Adaptive 2D FIR Filters Design for Subpixel Rendering (부화소 랜더링을 위한 내용적응형 2 차원 필터 설계)

  • Nam, Yeon Oh;Choi, Dong Yoon;Song, Byung Cheol
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.06a
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    • pp.107-108
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    • 2014
  • 부화소 기반 영상 축소기법은 각각의 부화소를 조절함으로써 픽셀 기반 영상 축소기법보다 해상도를 향상시킬 수 있는 방법이다. 그러나 부화소에 의한 해상도의 증가는 종종 색상정보의 왜곡을 발생시킨다. 부화소 랜더링의 주요과제는 선명도를 유지함과 동시에 색조왜곡현상을 억제하는 것이다. 선행연구들은 부화소랜더링을 위해 1 차원 혹은 2 차원 필터를 최적화 하였지만, 지역적인 특성을 고려하지 않았기 때문에 출력영상의 화질이 저하되는 현상이 발생한다. 본 논문은 위와 같은 문제를 해결하기 위해 내용적응형 2D FIR 필터를 제작방법을 제안한다. 제안필터는 충분한 수의 저해상도 패치와 고해상도 패치 쌍을 이용하여 임의의 고해상도 패치로부터 고화질의 저해상도 패치를 만들기 위한 최적의 내용적응형 2D FIR 필터를 학습한다. 학습된 필터에 의한 실험결과 제안하는 필터가 종례기법들 보다 색조왜곡현상이 현저히 줄어들고, 출력영상의 선명도를 유지함을 보여준다.

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