• Structural Engineering and Mechanics
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• v.20 no.3
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• pp.265-277
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• 2005

This paper is focused on fractal analysis of the surface cracking, a new tool for safety evaluation of corroded reinforced concrete (RC) beams. Comprehensive experimental investigations, including flexural tests, coupon tests on strength evaluation of corroded concrete and rusty rebar, and pullout tests to determine bond strength between concrete and rebar were carried out on nine Corroded Reinforced Concrete Beams (CRCB) exposed to an aggressive environment for more than 10 years. In combination with test results from a previous study on CRCBs fabricated in the laboratory from accelerated methods, it is found that, for both types of beams, the surface cracking distributions are fractal in character at loading and failure stages. Fractal dimension is calculated for all specimens at different corrosion states based on fractal analysis method. Relationships between the fractal dimension and mechanical properties of corroded concrete, rebar corrosion ratio, and ductility of CRCBs are discussed in detail. It is concluded that the fractal dimension can act as a damage index and can be efficiently used to describe the corrosion state of CRCBs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1737-1742
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• 2001

The fractal-based method for describing rubbed surface texture has aroused great interest. The determination of rubbed surface topography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe topography of the rubbed surface, the wear test was carried out with annular surfaces of wear testing specimens in dry friction. furthermore, the relation between the fractal dimensions and the frictional conditions are also investigated and fractal descriptors was applied to rubbed surface with image processing. Fractal dimension can be determined by sum of intensity difference of image surface pixel. Fractal dimension increased according as the applied load and sliding distance increase. Topography of the rubbed surface can be effectively obtained by fractal dimensions.

• Journal of Gifted/Talented Education
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• v.12 no.4
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• pp.120-130
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• 2002

We have analyzed students' reports on a problem for 'adhesive tape' and 'fractal diffraction' among ten assigned problems in the first Korean youth physics tournament (KYPT). There were three high school team' s reports and one middle school team' s report on this problem. However, many students failed to solve the 'fractal diffraction' problem correctly due to having no idea of fractal. This problem was found to be most difficult one for the participated students among ten assigned problems given in the first KYPT.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.387-392
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• 2005

The research was performed to predict the potential landslide with roughness index. It was known that fractal dimension and surface area index can be represented the topography, specially when the natural slopes were rough or rugged. A test site was selected and fractal dimension and surface area index were calculated from the irregular triangle network. Fractal dimension were ranged between $2.016{\sim}2.046$ and surface area index $1.56E+07{\sim}2.59E+07$. Surface area index increased as fractal dimension increased. Slope stability was calculated by infinite slope stability analysis model and was compared to slope stability by fractal and surface area index. In the result, unsafe zones where slope stability is under 1.1 were $5.11{\sim}6.25%$ for the test site. It can be said that fractal dimension and surface area index are a good index to evaluate the slope stability because when fractal dimension and surface area index are greater, then stability of the site is more unsafe.

• Journal of Korea Game Society
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• v.16 no.1
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• pp.119-128
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• 2016

In this paper, we consider an improved deformation method of IFS(iterated function system) fractal using codes of fractal points. In the existing deformation methods, the intermediate results of position dependent partial deformation propagate randomly due to the randomly selected maps of iteration. Therefore, in many cases, the obtained results become somewhat monotonous feeling shapes. To improve these limitations, we propose a method in which the selection of maps are controlled by codes of fractal points. Applying this method, we can obtain interesting fractal deformation conforming with its fractal features. Also, we propose a simple method, incorporating state variables, that can be applied to deformation of some fractal features other than position coordinates.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.494-498
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• 2007

Purpose: This study was done to know the usefulness of fractal analysis when evaluating the radiologic changes after decompression on jaw bone cystic lesions using fractal analysis. Materials and methods: 30cases of cystic lesions were followed up after decompression. Panoramic image was used to observe radiologic changes around the cystic lesion. The part of the panoramic image which showed radiologic change was defined as region of interest(ROI); The fractal dimension of the ROI was calculated using box-counting method. Results: Using sign-rank test, there was a statistically significant difference in fractal dimensions after decompression therapy(P<0.0001). The fractal dimensions statistically increased after decompression(the median of D:0.12). Conclusions: The ROI after decompression showed higher fractal dimensions which offer the objective proof of the bone healing around cystic lesions after decompression treatment.

• The Journal of the Korea Contents Association
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• v.20 no.11
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• pp.354-367
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• 2020

This study is on the consideration of the scope of application of art therapy and fractal through the review of literature at home and abroad. The complex system is the opposite of the Euclidean system, a concept suitable for understanding the contemporaries with ambiguous boundaries and decentralized phenomena. The self-similarity and inventiveness of fractal, the geometry of nature, is used as fractal art in art as well as tree trunk, cloud and plant, especially in art therapy, fractal is considered to be available in the field of mandala and neuroscience. From brain-based research to mandala, exposure to natural patterns, clinical diagnosis through fractal analysis and software development, fractal has potential elements that can be developed in art therapy. Fractal, which is easy to link with computers due to its nature, is a necessary study at this point when non-face-to-face contact with the Corona virus is recommended. Currently, research on fractal art therapy is insufficient in Korea. Therefore, this research is intended to present as a basis for scientific and objective diagnostic tools and treatment at clinical sites using art therapy using fractal.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.1-10
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• 2005

The purpose of this paper is to conduct an experimental measurement and analysis of cities' morphology. Fractal theory that is an effective tool for evaluating self-similarity and complexity of objects was applied. For the comparative analysis of fractailities and computational verification, two totally different cities in Japan were selected. They are Kitakyushu City, which is a big and fully developed city, and Jinguu Machi of which almost all the area is covered with agricultural land use. After converting vector data to raster data within GIS, fractal dimensions of two cases in Kitakyushu City and one case in Jinguu Machi were calculated. The calculation showed that two parts of Kitakyushu City were already fractal. Jinguu Machi, however, was difficult to find fractality. As a conclusion, fractal was proved to be an useful tool to estimate the shape of cities reflecting their internal spatial structure, that is self-similarity and complexity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4_1
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• pp.97-106
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• 1992

Total length of stream networks and main stream length vary with topographic map scales, and the stream length of drainage basin on topographic map can be viewed as a fractal. Total length of stream network and main stream length are represented as only stream area ratio($R_a$) based on Horton's laws, thereafter the fractal dimensions of stream network and main stream length are derived as a simple function of stream length($R_L$) and stream area ratios($R_a$) respectively. The derived equations of fractal dimension are applied to Sansung basin in Kum River and compared with the equations already existed. The stream network appeared as space filling with fractal dimension near 2 as map scale increases, while main stream length shows near 1. The results of this study are expected to be helpful in the quantitative analysis of drainage network composition with map scale.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.69-79
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• 2000

Fractal geometry has become one of prospective research approaches as the complex structure of natural entities is not easily characterized by traditional Euclidean geometry. With the fractal geometry, we can better decipher the complex structure and identify natural and anthropogenic agents of landscape patterns occurring at different spatial scales. The usefulness of fractal, however, has not been fully appreciated among Korean academic societies, especially in ecological and limnological fields. We attempt to address three points in this study. First, we introduce the concept and dimension of fractal and review relevant research approaches, especially with respect to ecological and limnological phenomena. Second, we explore possible applications of fractal to some aspects of geography and land use characteristics in South Korea. For the analyses of fractal dimensions, we used data published in other studies previously and collected for this study. Data were analyzed by a perimeter/area method of fractal dimension for the spatial distribution of global solar radiation and leaf area index, and the movement of wild boars in forested landscapes of mid-eastern Korea. The same approach was also applied to the water channel of a hypothetical river and the shape of reservoirs in Yongin, Kyunggi Province. Finally, we discuss the results and key issues to consider when a fractal approach is employed in ecology and limnology.