• Title/Summary/Keyword: local adaptive smoothing

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Historical Study on Density Smoothing in Nonparametric Statistics (비모수 통계학에서 밀도 추정의 평활에 관한 역사적 고찰)

  • 이승우
    • Journal for History of Mathematics
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    • v.17 no.2
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    • pp.15-20
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    • 2004
  • We investigate the unbiasedness and consistency as the statistical properties of density estimators. We show histogram, kernel density estimation, and local adaptive smoothing as density smoothing in this paper. Also, the early and recent research on nonparametric density estimation is described and discussed.

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Bandwidth Selection for Local Smoothing Jump Detector

  • Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • v.16 no.6
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    • pp.1047-1054
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    • 2009
  • Local smoothing jump detection procedure is a popular method for detecting jump locations and the performance of the jump detector heavily depends on the choice of the bandwidth. However, little work has been done on this issue. In this paper, we propose the bootstrap bandwidth selection method which can be used for any kernel-based or local polynomial-based jump detector. The proposed bandwidth selection method is fully data-adaptive and its performance is evaluated through a simulation study and a real data example.

Multistep Adaptive Smoothing Technique of Speckle Images (스펙클 영상의 다단계 적응 평활화 기법)

  • 김태균;남권문;박래홍
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.1
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    • pp.85-93
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    • 1992
  • In this paper, we propose a parameter-free smoothing method for speckle images, i.e., an adaptive least squares image smoothing technique implemented in a multistep environment. The pertinent smoothing window size at a given pixel is determined by the discontinuity measure which is defined by the ratio of the local variance and mean squares of intensity values of pixels over the smoothing window centered there. The mode of the discontinuity measure at each step is estimated to replace the noise variance parameter that is required in the adaptive smoothing. Computer simulation shows that the proposed multistep technique can smooth homogeneous regions satisfactorily while preserving fine details near boundaries.

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An edge-based smoothed finite element method for adaptive analysis

  • Chen, L.;Zhang, J.;Zeng, K.Y.;Jiao, P.G.
    • Structural Engineering and Mechanics
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    • v.39 no.6
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    • pp.767-793
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    • 2011
  • An efficient edge-based smoothed finite element method (ES-FEM) has been recently developed for solving solid mechanics problems. The ES-FEM uses triangular elements that can be generated easily for complicated domains. In this paper, the complexity study of the ES-FEM based on triangular elements is conducted in detail, which confirms the ES-FEM produces higher computational efficiency compared to the FEM. Therefore, the ES-FEM offers an excellent platform for adaptive analysis, and this paper presents an efficient adaptive procedure based on the ES-FEM. A smoothing domain based energy (SDE) error estimate is first devised making use of the features of the ES-FEM. The present error estimate differs from the conventional approaches and evaluates error based on smoothing domains used in the ES-FEM. A local refinement technique based on the Delaunay algorithm is then implemented to achieve high efficiency in the mesh refinement. In this refinement technique, each node is assigned a scaling factor to control the local nodal density, and refinement of the neighborhood of a node is accomplished simply by adjusting its scaling factor. Intensive numerical studies, including an actual engineering problem of an automobile part, show that the proposed adaptive procedure is effective and efficient in producing solutions of desired accuracy.

Video Stabilization Based on Smoothing Filter of Undesirable Motion (비의도 움직임 완화 필터 기반 동영상 안정화)

  • Kim, Beomsu;Lim, Jinju;Hong, Min-Cheol
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.244-253
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    • 2015
  • Please This paper presents method of video stabilization based on detection and adaptive motion smoothing filtering of undesirable motion. The proposed algorithm consists of two stages: the detection of undesirable motion and smoothing filtering of detected undesired motion. To incorporate desired properties into the motion smoothing process, the local maximum and the local minimum are defined in a set composed of the parameters of accumulative global motion. Using the local information, the constraints on detecting undesirable motions are defined. Based on these constraints, the alpha parameter of the alpha-trimmed means filter is adjusted, so that the degree of motion smoothing in the reconstructed video sequence is controlled. The experimental results demonstrated the capability of the proposed algorithm.

Triangular Grid Homogenization Using Local Improvement Method (국소개선기법을 이용한 삼각격자 균질화)

  • Choi, Hyung-Il;Jun, Sang-Wook;Lee, Dong-Ho;Lee, Do-Hyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.8
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    • pp.1-7
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    • 2005
  • This paper proposes a local improvement method that combines extended topological clean up and optimization-based smoothing for homogenizing triangular grid system. First extended topological clean up procedures are applied to improve the connectivities of grid elements. Then, local optimization-based smoothing is performed for maximizing the distortion metric that measures grid quality. Using the local improvement strategy, we implement the grid homogenizations for two triangular grid examples. It is shown that the suggested algorithm improves the quality of the triangular grids to a great degree in an efficient manner and also can be easily applied to the remeshing algorithm in adaptive mesh refinement technique.

Image Enhancement for Epigraphic Image Using Adaptive Process Based on Local Statistics (국부통계근거 적응처리에 의한 금석문영상 향상)

  • Hwang, Jae-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.2 s.314
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    • pp.37-45
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    • 2007
  • We propose an adaptive image enhancement method for epigraphic images, which is based on local statistics. Local statistics of the image are utilized for adaptive realization of the enhancement, that controls the contribution of the smoothing or sharpening paths. Image contrast enhancement occurs in details and noises are suppressed in smooth areas. For modeling the epigraphic image, pre~process is achieved by HSDI(Hanzi squeezed digital image). We have calculated the local statistics from this HSDI model. Application of this approach to HSDI has shown that processing not only smooths the background areas but also improves the subtle variations of edges, so that the word regions can be enhanced. Experimental results show that the proposed algorithm has better performance than the conventional image enhancement ones.

Adaptive Smoothing Based on Bit-Plane and Entropy for Robust Face Recognition (환경에 강인한 얼굴인식을 위한 CMSB-plane과 Entropy 기반의 적응 평활화 기법)

  • Lee, Su-Young;Park, Seok-Lai;Park, Young-Kyung;Kim, Joong-Kyu
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.869-870
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    • 2008
  • Illumination variation is the most significant factor affecting face recognition rate. In this paper, we propose adaptive smoothing based on combined most significant bit (CMSB) - plane and local entropy for robust face recognition in varying illumination. Illumination normalization is achieved based on Retinex method. The proposed method has been evaluated based on the CMU PIE database by using Principle Component Analysis (PCA).

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Local Similarity based Document Layout Analysis using Improved ARLSA

  • Kim, Gwangbok;Kim, SooHyung;Na, InSeop
    • International Journal of Contents
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    • v.11 no.2
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    • pp.15-19
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    • 2015
  • In this paper, we propose an efficient document layout analysis algorithm that includes table detection. Typical methods of document layout analysis use the height and gap between words or columns. To correspond to the various styles and sizes of documents, we propose an algorithm that uses the mean value of the distance transform representing thickness and compare with components in the local area. With this algorithm, we combine a table detection algorithm using the same feature as that of the text classifier. Table candidates, separators, and big components are isolated from the image using Connected Component Analysis (CCA) and distance transform. The key idea of text classification is that the characteristics of the text parallel components that have a similar thickness and height. In order to estimate local similarity, we detect a text region using an adaptive searching window size. An improved adaptive run-length smoothing algorithm (ARLSA) was proposed to create the proper boundary of a text zone and non-text zone. Results from experiments on the ICDAR2009 page segmentation competition test set and our dataset demonstrate the superiority of our dataset through f-measure comparison with other algorithms.

Adaptive MAP High-Resolution Image Reconstruction Algorithm Using Local Statistics (국부 통계 특성을 이용한 적응 MAP 방식의 고해상도 영상 복원 방식)

  • Kim, Kyung-Ho;Song, Won-Seon;Hong, Min-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.12C
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    • pp.1194-1200
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    • 2006
  • In this paper, we propose an adaptive MAP (Maximum A Posteriori) high-resolution image reconstruction algorithm using local statistics. In order to preserve the edge information of an original high-resolution image, a visibility function defined by local statistics of the low-resolution image is incorporated into MAP estimation process, so that the local smoothness is adaptively controlled. The weighted non-quadratic convex functional is defined to obtain the optimal solution that is as close as possible to the original high-resolution image. An iterative algorithm is utilized for obtaining the solution, and the smoothing parameter is updated at each iteration step from the partially reconstructed high-resolution image is required. Experimental results demonstrate the capability of the proposed algorithm.