• Title/Summary/Keyword: restoration method

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A Study on Outage Restoration Guide Including Load Cutoff in Distribution System (부하차단을 포함한 배전계통 정전복구방안에 관한 연구)

  • 김세호
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.1
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    • pp.98-104
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    • 2004
  • This paper represents the fast and efficient load transfer guide for fault or outage restoration in distribution system. For restoration guide, system trace is performed to reverse direction(source side) from tie breaker in tree-structured distribution network. Search space and breaker's combinational number for restoration guide are greatly reduced. It is proposed the load transfer method including first stage restoration(single load transfer, double load transfer, triple load transfer), second stage restoration(transferring load to neighboring feeder in order to expand the capacity margin) and load cutoff guide. The proposed method can be easily applied to primary customer restoration, multi-fault recovery and distribution automation system.

Visual Quality Enhancement of Three-Dimensional Integral Imaging Reconstruction for Partially Occluded Objects Using Exemplar-Based Image Restoration

  • Zhang, Miao;Zhong, Zhaolong;Piao, Yongri
    • Journal of information and communication convergence engineering
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    • v.14 no.1
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    • pp.57-63
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    • 2016
  • In generally, the resolution of reconstructed three-dimensional images can be seriously degraded by undesired occlusions in the integral imaging system, because the undesired information of the occlusion overlap the three-dimensional images to be reconstructed. To solve the problem of the undesired occlusion, we present an exemplar-based image restoration method in integral imaging system. In the proposed method, a minimum spanning tree-based stereo matching method is used to remove the region of undesired occlusions in each elemental image. After that, the removed occlusion region of each elemental images are re-established by using the exemplar-based image restoration method. For further improve the performance of the image restoration, the structure tensor is used to solve the filling error cause by discontinuous structures. Finally, the resolution enhanced three-dimensional images are reconstructed by using the restored elemental images. The preliminary experiments are presented to demonstrate the feasibility of the proposed method.

Regularized Iterative Image Restoration with Relaxation Parameter (이완변수를 고려한 영상의 정칙화 반복 복원)

  • 홍성용;이태홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.1
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    • pp.91-99
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    • 1994
  • We proposed the regularized iterative restoration method considering relaxation parameter and regularization paramenter in order to restore the noisy motion-blurred images. We used (i-H) as a regularization operator and these two kinds of constraints were applied while conventional regularization iterative restoration method proposed by Jan Biemond et al used the 2-D Laplacian filter and a predetermined regularization parameter value and relaxation parameter to 1. Through the experimental results, we showed better results compared with those by a conventional method and or regularized iterative restoration method just considering only a regularization parameter. These two kinds of constratints have good effects when applied into the regularized iterative restoration method for noisy motion-blurred images.

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Multiscale Regularization Method for Image Restoration (다중척도 정칙화 방법을 이용한 영상복원)

  • 이남용
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.3
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    • pp.173-180
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    • 2004
  • In this paper we provide a new image restoration method based on the multiscale regularization in the redundant wavelet transform domain. The proposed method uses the redundant wavelet transform to decompose the single-scale image restoration problem to multiscale ones and applies scale dependent regularization to the decomposed restoration problems. The proposed method recovers sharp edges by applying rather less regularization to wavelet related restorations, while suppressing the resulting noise magnification by the wavelet shrinkage algorithm. The improved performance of the proposed method over more traditional Wiener filtering is shown through numerical experiments.

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FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION ACCORDING TO THE METHOD OF RESTORATION AFTER ROOT CANAL THERAPY (상악 소구치 근관치료후 수복방법에 따른 응력 분포의 유한 요소 분석)

  • Lee, Chung-Sik;Lee, Jae-Young;Cho, Hyo-Sun
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.339-352
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    • 1996
  • Many dentists have been taken an interest in restoration of severly damaged teeth after endodontic treatment and it is a true that there are lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the effects of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper 1st premolar was severly damaged, and after the root canal therapy, two most common types of restoration were carried out ; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with amalgam core and gold crown. After restoration, in order to present the concentration of stress at internal portion of the tooth and the surrounding periodontal tissue, we doveloped a 2-dimensional finite element model of labiopalatal section, then loaded forces from 2 long perpendicular to the lingual incline of buccal ridge an the middle point, parallel to the long direction axis of tooth at the fossa-were applied. The analyzed results were as follows : 1. Stress of the normal first premolar was concentrated on the most weakest anatomical structure, that is, cervical area, and no stress on the bifurcated area of the canal. 2. Crown restoration after root canal therapy causes large stress concentration on the bifurcated area of the canal. This stress concentration has larger value in case of lateral movement of mandible, and there are decrease in the stress concentration compared with natural tooth. 3. Coronal-radicular amalgam restoration method transports more stress to the tooth structure than restoration using Para-Post. 4. There are more stress concentration around Para-Post in the case of lateral movement, and we have more favo rable result when restored with Para-Post. 5. Generally, stress in the lateral movement is larger than stress in the perpendicular load.

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Watermarking Algorithm that is Adaptive on Geometric Distortion in consequence of Restoration Pattern Matching (복구패턴 정합을 통한 기하학적 왜곡에 적응적인 워터마킹)

  • Jun Young-Min;Ko Il-Ju;Kim Dongho
    • The KIPS Transactions:PartB
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    • v.12B no.3 s.99
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    • pp.283-290
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    • 2005
  • The mismatched allocation of watermarking position due to parallel translation, rotation, and scaling distortion is a problem that requires an answer in watermarking. In this paper, we propose a watermarking method robust enough to hold against geometrical distorting using restoration pattern matching. The proposed method defines restoration pattern, then inserts the pattern to a watermark embedded image for distribution. Geometrical distortion is verified by comparing restoration pattern extracted from distributed image and the original restoration pattern inserted to the image. If geometrical distortion is found, inverse transformation is equally performed to synchronize the watermark insertion and extraction position. To evaluate the performance of the proposed method, experiments in translation, rotation, and scaling attack are performed.

Image Reconstruction of Sinogram Restoration using Inpainting method in Sparse View CT (Sparse view CT에서 inpainting 방법을 이용한 사이노그램 복원의 영상 재구성)

  • Kim, Daehong;Baek, Cheol-Ha
    • Journal of the Korean Society of Radiology
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    • v.11 no.7
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    • pp.655-661
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    • 2017
  • Sparse view CT has been widely used to reduce radiation dose to patient in radiation therapy. In this work, we performed sinogram restoration from sparse sampling data by using inpainting method for simulation and experiment. Sinogram restoration was performed in accordance with sampling angle and restoration method, and their results were validated with root mean square error (RMSE) and image profiles. Simulation and experiment are designed to fan beam scan for various projection angles. Sparse data in sinogram were restored by using linear interpolation and inpainting method. Then, the restored sinogram was reconstructed with filtered backprojection (FBP) algorithm. The results showed that RMSE and image profiles were depended on the projection angles and restoration method. Based on the simulation and experiment, we found that inpainting method could be improved for sinogram restoration in comparison to linear interpolation method for estimating RMSE and image profiles.

A Review of Stream Assessment Methodologies and Restoration: The Case of Virginia, USA

  • Bender, Shera M.;Ahn, Chang-Woo
    • Environmental Engineering Research
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    • v.16 no.2
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    • pp.69-79
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    • 2011
  • Rapid population growth and land use changes have severely degraded streams across the United States. In response, there has been a surge in the number of stream restoration projects, including stream restoration for mitigation purposes. Currently, most projects do not include evaluation and monitoring, which are critical in the success of stream restoration projects. The goal of this study is to review the current status of assessment methodologies and restoration approaches for streams in Virginia, with the aim of assisting the restoration community in making sound decisions. As part of the study, stream restoration projects data from a project in Fairfax County, Virginia was assessed. This review revealed that the stream assessment methodologies currently applied to restoration are visuallybased and do not include biological data collection and/or a method to incorporate watershed information. It was found from the case study that out of the twenty nine restoration projects that had occurred between 1995 and 2003 in Fairfax County, nineteen projects reported bank stabilization as a goal or the only goal, indicating an emphasis on a single physical component rather than on the overall ecological integrity of streams. It also turned out that only seven projects conducted any level of monitoring as part of the restoration, confirming the lack of evaluation and monitoring. However, Fairfax County has recently improved its stream restoration practices by developing and incorporating watershed management plans. This now provides one of the better cases that might be looked upon by stakeholders when planning future stream restoration projects.

Self-Regularization Method for Image Restoration (영상 복원을 위한 자기 정규화 방법)

  • Yoo, Jae-Hung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.1
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    • pp.45-52
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    • 2016
  • This paper suggests a new method of finding regularization parameter for image restoration problems. Wiener filter requires priori information such that power spectrums of original image and noise. Constrained least squares restoration also requires knowledge of the noise level. If the prior information is not available, separate optimization functions for Tikhonov regularization parameter are suggested in the literature such as generalized cross validation and L-curve criterion. In this paper, self-regularization method that connects bias term of augmented linear system and smoothing term of Tikhonov regularization is introduced in the frequency domain and applied to the image restoration problems. Experimental results show the effectiveness of the proposed method.