• Korean Journal of Remote Sensing
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• v.36 no.4
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• pp.503-513
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• 2020

This paper presents a method to evaluate denoising filters based on edge locations in their denoised images. Image quality assessment has often been performed by using structural similarity (SSIM). However, SSIM does not provide clearly the geometric accuracy of features in denoised images. Thus, in this paper, a method to localize edge locations with subpixel accuracy based on adaptive weighting of gradients is used for obtaining the subpixel locations of edges in ground truth image, noisy images, and denoised images. Then, this paper proposes a method to evaluate the geometric accuracy of edge locations based on root mean squares error (RMSE) and jaggedness with reference to ground truth locations. Jaggedness is a measure proposed in this study to measure the stability of the distribution of edge locations. Tested denoising filters are anisotropic diffusion (AF), bilateral filter, guided filter, weighted guided filter, weighted mean of patches filter, and smoothing filter (SF). SF is a simple filter that smooths images by applying a Gaussian blurring to a noisy image. Experiments were performed with a set of simulated images and natural images. The experimental results show that AF and SF recovered edge locations more accurately than the other tested filters in terms of SSIM, RMSE, and jaggedness and that SF produced better results than AF in terms of jaggedness.

• Journal of Magnetics
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• v.15 no.3
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• pp.99-102
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• 2010

We present the fractal properties of the magnetic domain walls in $(5-{\AA}\;Co_{90}Fe_{10}/10-{\AA}\;Pt)_n$ multilayer films with perpendicular magnetic anisotropy for the number of repeats n (1 to 5). In these films, the magnetization reversed due to the domain wall propagation throughout the films with rare nucleations. As n increased, it was observed that the jaggedness of the domain walls increased noticeably, which is possibly due to the accumulation of irregularities at the layer interfaces. The jaggedness of the domain walls was analyzed in terms of the fractal dimension by use of the ruler method, and it was revealed that the fractal dimension significantly changed from $1.0{\pm}0.002$ to $1.3{\pm}0.05$ as n increased from 1 to 5.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.48-60
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• 2020

The purpose of this study is to analyze the patterns and characteristics of changes in integrated process skills during the process of science high school students' inquiry by using group-based trajectory modeling. 59 students participated in this study. Three hypothetico-deductive inquiry tasks were used as an intervention activity. We asked science high school students to perform those three tasks sequentially and to generate reports of the process and results. We evaluated students' reports by four elements (designing inquiry, collecting data, analyzing data, and forming conclusion) of the integrated process skills according to the scoring rubric developed by Lee and Park (2017), and analyzed the level of changes in integrated process skills in those three inquiry tasks by using group-based trajectory modeling. In addition, we analyzed the characteristics of changes in integrated process skills from several perspectives. The findings are as follows: First, concerning the change patterns of students' integrated process skills, all of the four elements were classified into two groups, but the change patterns were very different by elements. Second, regarding the change characteristics of students' integrated process skills, we found the context-dependency of integrated process skills, variation of learning progression for integrated process skills, and jaggedness of integrated process skills level. Based on these findings, we suggested that a couple of ways be sought to improve the integrated process skills of science high school students.