• Title/Summary/Keyword: Fractal

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Analysis of Filamentous Fungal Growth and Pellets Formation by Fractal Geometry (Fractal 기하학을 이용한 균사의 성장과 구체 형성의 특성 분석)

  • 류두현
    • KSBB Journal
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    • v.10 no.2
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    • pp.119-125
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    • 1995
  • The morphology of fungal growth, which is an important variable for separability and rheological property of fermented medium, was quantified with fractal geometry Fractal dimensions were determined for submerged growth of two industrially important fungi, Aspergillus niger and Aspergillus oruzae. The tendency of pellet formation was related to the fractal dimension of fungi.

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Application of Fractal Dimension for Morphological Analysis of Wear Particle (마멸입자 형태해석을 위한 Fractal 차원의 적용)

  • 오동석;조연상;서영백;박흥식;전태옥
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.115-123
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    • 1998
  • The morphological analysis of wear particle is a very effective means for machine condition monitoring and fault diagnosis. In order to describe morphology of various wear particle, the wear test was carried out under different experimental conditions. And fractal descriptors was applied to boundary and surface of wear particle with image processing system. These descriptors to analyze shape and surface wear particle are shape fractal dimension and surface fractal dimension. The shape fractal dimension can be derived from the boundary profile and surface fractal dimension can be determined by sum of intensity difference of surface pixel. The morphology of wear particles can be effectively obtained by two fractal dimensions.

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Roundness Modelling by Fractal Interpolation (프랙탈 보간에 의한 진원도 모델링)

  • Yoon, Moon-Chul;Kim, Byung-Tak;Chin, Do-Hun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.3
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    • pp.67-72
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    • 2006
  • There are many modelling methods using theoretical and experimental data. Recently, fractal interpolation methods have been widely used to estimate and analyze various data. Due to the chaotic nature of dynamic roundness profile data in roundness some desirable method must be used for the analysis which is natural to time series data. Fractal analysis used in this paper is within the scope of the fractal interpolation and fractal dimension. Also, two methods for computing the fractal dimension has been introduced which can obtain the dimension of typical dynamic roundness profile data according to the number of data points in which the fixed data are generally lower than 200 data points. This fractal analysis result shows a possible prediction of roundness profile that has some different roundness profile in round shape operation.

Analysis of Filamentous Fungal Growth and Pellets Formation by Fractal Geometry (Fractal 기하학을 이용한 균사의 성장과 구체 형성의 특성 분석)

  • 류두현
    • KSBB Journal
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    • v.9 no.5
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    • pp.512-517
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    • 1994
  • The morphology of fungal growth, which is an important variable for separability and rheological property of fermented medium, was quantified with fractal geometry. Fractal dimensions were determined for submerged growth of two industrially important fungi, Aspergillus niger and Aspergillus oryzae. The tendency of pellet formation was related to the fractal dimension of fungi.

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The Properties of Devices Surface by Fractal Dimension (프랙탈 차원에 의한 소자 표면의 특성)

  • Hong, Kyung-Jin;Min, Yong-Ki;Cho, Jae-Cheol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.05a
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    • pp.149-151
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    • 2006
  • The surface properties of electrical devices studied by fractal phenomenon were investigated. The SEM photographs of devices surface were changed by binary code and it were analyzed by fractal dimension. The void of devices surface was found by fractal program. The relation between grain density and electrical properties are able to expect to fractal dimension. The grain size in varistors surface was decreased by increasing of oxide antimony addition. The fractal dimension and electrical properties of devices surface was related to between grain boundary and grain density. The grain size was decreased by increasing of fractal dimensions.

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Thinning of 2D and 3D Fractal Antenna Arrays with Bounded and Unbounded Fractal Distribution Functions for Celestial Communications

  • Ponnapalli, Venkata Aditya Sankar;Jayasree, Pappu Venkata Yasoda
    • ETRI Journal
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    • v.38 no.6
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    • pp.1135-1144
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    • 2016
  • Fractal antenna arrays are geometry-based thinned arrays having multiband applications. The major challenge of these arrays is their large number of elements at higher expansion factors. This article presents the thinning of fractal antenna arrays while maintaining an appropriate balance between the side lobe level and beam width by using various quantized fractal distribution functions. A 2D square fractal antenna array and 3DSierpinski gasket antenna array are considered in this article to validate the proposed distribution functions. Nearly one third of the antenna elements are thinned in each successive iteration except in the case of a one-count distribution function. The proposed technique can simplify practical implementation and exhibits better performance for various parameters such as the side lobe level, side lobe angle, and half power beam width than fully populated fractal antenna arrays.

Application of Fractal Parameter for Morphological Analysis of Wear Particle (마멸입자 형상분석을 위한 프랙탈 파라미터의 적용)

  • 원두원;전성재;조연상;박흥식;전태옥
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.30-35
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    • 2001
  • The morphological analysis of wear particle is a very effective means for machine condition monitoring and fault diagnosis. In order to describe morphology of various wear particle, the wear test was carried oui under friction experimental conditions. And fractal descriptors was applied to boundary and surface of wear particle with image processing system. These descriptors to analyze shape and surface wear particle are share fractal dimension and surface fractal dimension. The boundry fractal dimension can be derived from the boundary profile and surface fractal dimension can be determined b)r sum of intensity difference of surface pixel. The morphology of wear particles can be effectively obtained by two fractal dimensions.

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Evaluation of the Effect of using Fractal Feature on Machine learning based Pancreatic Tumor Classification (기계학습 기반 췌장 종양 분류에서 프랙탈 특징의 유효성 평가)

  • Oh, Seok;Kim, Young Jae;Kim, Kwang Gi
    • Journal of Korea Multimedia Society
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    • v.24 no.12
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    • pp.1614-1623
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    • 2021
  • In this paper, the purpose is evaluation of the effect of using fractal feature in machine learning based pancreatic tumor classification. We used the data that Pancreas CT series 469 case including 1995 slice of benign and 1772 slice of malignant. Feature selection is implemented from 109 feature to 7 feature by Lasso regularization. In Fractal feature, fractal dimension is obtained by box-counting method, and hurst coefficient is calculated range data of pixel value in ROI. As a result, there were significant differences in both benign and malignancies tumor. Additionally, we compared the classification performance between model without fractal feature and model with fractal feature by using support vector machine. The train model with fractal feature showed statistically significant performance in comparison with train model without fractal feature.

Extraction of Fractal Shape Characteristics of Wear Particles in Lubricant (윤활유 중지 마멸입자의 프랙탈 형상특징 추출 방법)

  • Park, Heung-Sik;Woo, Kyu-Sung;Cho, Yon-Sang;Kim, Dong-Ho;Ye, Gyoo-Heon
    • Tribology and Lubricants
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    • v.22 no.5
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    • pp.276-281
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    • 2006
  • The fractal dimension is quantitatively to define the irregular characteristic of the shape in natural. It can be useful in describing morphological characteristics of various wear particles. This paper was undertaken to diagnose failure condition for sliding members in lubrication by fractal dimension. It will be possible to diagnose wear mechanism, friction and damage state of machines through analysis of shape characteristics for wear particle on driving condition by fractal parameters. In this study, the calculating and analyzing methods of fractal dimensions were constructed for the condition monitoring and wear particle analysis in lubricant condition. So, we carried out the Friction and wear test with the ball on disk type tester, and the fractal parameters of wear particle in lubricated conditions were calculated. Fractal parameters were defined as texture fractal dimension ($D_{t}$), structure fractal dimension ($D_{s}$) and total fractal dimension (D).

Fractal Properties and Cognitive Ecological effects in Space Design - Focused on Landscape Pattern - (공간디자인에 적용된 프랙탈 특성의 인지생태론적 효과 - 랜드스케이프 패턴을 중심으로 -)

  • Kim, Joo-Mi
    • Korean Institute of Interior Design Journal
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    • v.20 no.2
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    • pp.120-130
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    • 2011
  • The purpose of this study is to propose cognitive ecological effects of fractal patterns in space design. This study investigated the perception and cognition problems regarding landscape patterns showing fractal properties from the cognitive perspective instead of the traditional speculative approach. In particular, the researcher has verified that fractal geometry theory and fractal pattern concept provide insight in space aesthetic values and cognitive effects. Research results are as follows. First, most environmentally-friendly fractal urban forms provide cognitive connectivity. In particular, this space provides a positive emotional response and preference to humans and displays self-organized complexity. This study found that such complexity of space form has characteristics corresponding to parallel cognitive structures of the human brain. Simultaneously, the researcher suggests that the fractal landscape pattern is an alternative for stiff and homogenized modern space. Second, fractal patterns provide hierarchical connectivity within the brain through continuous difference and repetition. In particular, self-similarities of fractal patterns administer significant visual grouping and coherence in human perception. It can be determined whether scaling coherence facilitates easier organization in cognitive organization. Third, fractal patterns in space design provide the basic method for achieving the connection between concept, construction, and urban factors. As a result, the researcher has suggested that scale distribution of geometrical factors, such as fractal patterns, an be a design method to connect various space typologies.