• Title/Summary/Keyword: fractal geometry

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A Study on Application of Fractal Dimension in Analysis of Damage Mechanics in Rock (암반의 손상역학 해석에 있어서 Fractal차원의 적용에 관한 연구)

  • 정교철;정영기
    • The Journal of Engineering Geology
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    • v.4 no.2
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    • pp.139-151
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    • 1994
  • Rocks are composed of the discrete elements of microstructures such as different grains and microcracks. The studies of these microstructures are of increasing interest in engineering geology and civil engineering related to construction of a deep under-ground space. Accordingly, instead of a simplified continuum approach, discrete structural elements and mechanical properties of various grains must be accounted. But it is difficult to analyse crack and discontinuity surfaces in Euclidean geometry. So, Mandelbrot( 1983) developed fractal theory to manage irregular body in nature. In this study, geometrical properties of microstructures to estimate a relation between crack propagation and stress were calculated. Then it is shown that fractal theory can be applied to research real mechanical behavior of rocks.

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Hybrid Fractally Expanded Cross Antenna (하이브리드 후렉틀 확장 크로스 안테나)

  • 장정민;이상설
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.8
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    • pp.1329-1336
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    • 2000
  • A new fractal geometry of the traveling wave type cross antenna is newly presented. In the conventional type of the traveling wave antenna, the electrical length of the radiating conductor increases as the order of fractal expansion increases. But, increased length of the current path degrades the performance of the antenna from the various loss mechanism of the traveling wave type antenna. To reduce the antenna performance degradation, the new hybrid fractal antenna, which divides the entire fractal structure into some smaller ones and connects each smaller fractal group with a power divider is presented. The secondly, thirdly and fourthly expanded hybrid fractal cross antennas are fabricated and their performances are examined by measurements. Influences of the fractal order to the antenna performance are examined.

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Stationary Dual-Porosity Fractal Model of Groundwater Flow in Fractured Aquifers (균일대수층내 지하수 유동에 관한 정상류의 이중공극 프락탈 모델)

  • ;Bidaux, Pasal
    • The Journal of Engineering Geology
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    • v.4 no.2
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    • pp.127-138
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    • 1994
  • The stationary dual-porosity model is not sufficient to describe the hydraulic characteristics of fractured aquifers as the groundwater flow in fractured aquifers is often controlled by the fractal geometry of fractures. This study deals with new stationary dual-porosity fractal model. This model simulates pseudo-steady state flow from matrix block to fissure in the fractal aquifer. Furthermore, it considers storage capacity and well loss effect at the production well. Type curves for different flow dimensions with different drainage factors are plotted. This new model has been applied to experimental data. The result of the interpretation shows a good accordance between the theoretical model and the observed data.

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A Study on Fracture Surface of Aged Turbine by Fractal Dimension

  • Kim, Amkee;Nahm, Seung-Hoon
    • Journal of Mechanical Science and Technology
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    • v.15 no.10
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    • pp.1417-1422
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    • 2001
  • Since fracture surface presents clear evidence to describe the circumstances of material failure event, analysis of fracture surface should provide plenty of useful information for failure prevention. Thus if we extract proper information from the fracture surface, the safety evaluation, for plant component could be more accurate. In general, the chaotic morphology of fracture surface is determined by the degree of material degradation as well as by other factors such as type of load, geometry of specimen, notch condition, microstructure of material and environment. In this research, we developed a fractal analysis technology for the fracture surface of aged turbine rotor steel based on the slit-island technique using an image analyzer. Moreover the correlation between the fractal dimension and the aging time was studied.

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A Study on the Characteristics of Microstrip Patch Antenna with Frequency Selective Surface with Fractal Slot (프랙탈 슬롯을 가진 주파수 선택적 평면(FSS)에 의한 마이크로스트립 패치 안테나의 특성 연구)

  • Shim, Jae-Ruen
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.7
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    • pp.1242-1246
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    • 2007
  • In this study, FSS(Frequency Selective Surface) with Koch Fractal Curve slot is positioned on the conventional single layer microstrip patch antenna. Numerical results of the proposed antenna bandwidth and the antenna gain are increased compared with those of the conventional single layer microstrip patch antenna. In the future, the fractal geometry of the slot in FSS(Frequency Selective Surface) as a supplementary microstrip patch is researched for the enhancement of the microstrip patch antenna characteristics.

Compact and Flexible Monopole Antenna for Ultra-Wideband Applications Deploying Fractal Geometry

  • Geetha, G;Palaniswamy, Sandeep Kumar;Alsath, M. Gulam Nabi;Kanagasabai, Malathi;Rao, T. Rama
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.400-405
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    • 2018
  • This paper presents a compact ultra-wideband (UWB) flexible monopole antenna design on a paper substrate. The proposed antenna is made of iterations of a circular slot inside an octagonal metallic patch. This fractal-based geometry has been deployed to achieve compactness along with improved bandwidth, measured reflection coefficient -10 dB bandwidth ranging from 2.7 to 15.8 GHz. The overall size of the antenna is $26mm{\times}19mm{\times}0.5mm$, which makes it a compact one. The substrate used is paper and the main features like environment friendly, flexibility, green electronics applications and low cost of fabrication are the key factors for the proposed antenna. The aforementioned UWB prototype is suitable for many wireless communication systems such as WiMAX, WiFi, RFID and WSN applications. Antenna has been tested for the effect of bending by placing it over a curved surface of a very small radius of 10 mm.

A Point of View on the Use of Fractals in Art Therapy (미술치료에서 프랙탈의 활용방안에 관한 소고)

  • Lee, Hyun-Jee;Yeon, Ohk-Hyun
    • 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.

A Study of Non-Linear Characteristics in the Interior Space (실내공간의 비선형적 특성 분석에 관한 연구)

  • Lee, Eun-Jung;Han, Young-Ho
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2006.05a
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    • pp.206-209
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    • 2006
  • The concept of non-linearity, which has been derived from a scientific paradigm, has generated new discourse in formative arts. The non-linearity enables various new possibilities such as, generation of diverse and dynamic space, creation of non-geometric form and space, and the shape in the space as it is in nature. This study percepts and explains the concepts of non-linearity and their principles in space modeling in the field of interior design, in terms of the philosophy of fractal geometry. We also analyze cases, which shows trends and specific embodiments of non-linear space modeling. This study will provide perspectives on the non-linearity as a new methods in the space modeling. For the study, we review the concept and characteristics of non-linearity, by examining various literatures, and developed an analyzing tool which was used to study various cases of Western and Korean interior Design.

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