• KSBB Journal
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• 제10권2호
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• pp.119-125
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• 1995

균류를 이용하는 생물공정의 생산성, 분리성, 유변 학적 성질에 영향을 미치는 중요한 변수인 균류의 형태를 fractal 차원을 사용하여 정량화하였다. 산업적으로 중요한 균류인 Aspegillus oryzae와 Aspergil Ius niger가 초기의 접종 포자량과 탄소원의 놓도를 변화시켜 액상배지에서 성장하는 경우 디지탈 영상 분석장치를 사용하여 fractal 차원을 계산하였다. 균 샤가 형성하는 구체의 특성과 fractal로 표현된 균사 의 형태와의 상관관계를 구하였다. 일반적으로 낮은 fractal 차원의 균사가 낮은 밀도(compactness)의 구체를 형 성하고 외부의 모양이 불규칙 척 이 었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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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.

• 한국공작기계학회논문집
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• 제15권3호
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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.

• KSBB Journal
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• 제9권5호
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• pp.512-517
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• 1994

균류를 이용하는 생물공정의 생산성, 분리성, 유변 학적 성질에 영향을 주는 중요한 변수인 균류의 형 태를 fractal 차원을 사용하여 정량화하였다. 산업적 으로 중요한 균류인 Aspegillus oryzae와 Aspergil­l Ius niger가 초기의 접종 포자량과 탄소원의 농도를 변화시켜 액상배지에서 성장하는 경우, 디지탈 영상 분석장치를 사용하여 fractal 차원을 계산하였다. 균 사가 형성하는 구체의 특성과 fractal로 표현된 균사 의 형태와의 상관관계를 구하였다. 일반적으로 낮은 fractal 차원의 균사가 낮은 멜도(compactness)의 구체를 형성하고 외부의 모양이 불규칙적이었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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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.

• ETRI Journal
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• 제38권6호
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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.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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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.

• 한국멀티미디어학회논문지
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• 제24권12호
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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.

• Tribology and Lubricants
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• 제22권5호
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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).

• 한국실내디자인학회논문집
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• 제20권2호
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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.