• 한국수자원학회논문집
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• 제54권1호
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• pp.49-60
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• 2021

본 연구에서는 Fractal 나무의 개념을 이용하여 자연유역의 두 가지 개별적 Fractal 차원을 추정하는 방법을 제시하고자 한다. 이를 위하여 Fractal 나무의 성장 과정을 기반으로 유역 내부에서 발생 가능한 모든 배수 경로를 추출하여 완전한 배수망을 구성하고 이에 해당하는 Fractal 특성을 분석해 보고자 한다. 유역 내부에서 Fractal 나무의 성장 과정은 하천 유동의 특성을 가지는 배수 경로에서만 제한적으로 나타날 수 있다. 소규모 유역의 경우 Fractal 나무의 성장 단계에 따라 망상 구조의 분기 특성이 단일 하천 구간의 사행 특성에 비하여 민감하게 변화하여 단일한 망상 구조 속에서도 다양한 분기 구조가 생성될 수 있다. 따라서 소규모 유역을 대상으로 한 망상 구조에 대한 Fractal 차원은 단일한 수치의 고정된 형태보다는 범위의 형태로 취급되어야 하는 것이 타당한 것으로 판단된다. 또한, 소규모 유역의 배수 구조에 대한 분석에는 지형도나 수치지도로부터 추출한 하천망보다 본 연구에서 제시한 Fractal 나무의 성장에 따른 망상 구조와 같은 정보가 더 유용할 수 있을 것으로 판단된다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.167-171
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• 2006

It has been well known that customer' needs have much influence on the structure of supply chains. Uncertainty in customer demands forces companies' supply chains to be very flexible. When a company can not meet customers' changing needs, competitiveness in market places will be jeopardized. To survive in the competitive market places, structure of supply chains should be reconfigurable. In this paper, fractal concept is adopted to handle the reconfigurable issue. In a fractal-based SCM, structure of supply chains can be automatically reconfigured through the dynamic restructuring process with a fractal goal model. Goal in the system is divided into sub-goals, which are represented by a fractal goal model. The fractal goal model is a formal model which can be evaluated, changed, and scaled easily. Thus a well-designed fractal goal model is indispensable for a fractal-based SCM, and enhances the reconfigurability. Fractal structure for reconfigurable SCM is designed and presented. Fractal goal model is applied to SCM and an exemplary case is also briefly illustrated.

• Journal of Advanced Marine Engineering and Technology
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• 제22권4호
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• pp.522-528
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• 1998

This paper presents a fundamental fractal characteristics of the growing crack that has an irregularity producing a zigzag crack contour. This irregularity is analysed by a fractal geometry in a box counting method that is a very simple technique. First the fractal dimensions and actual fractal extensive crack length are obtained. Also a fractal fracture energy relation with a fractal dimension is found so as to get fractal crack behaviors. Thus it can be shown that the fractal dimension has a possibility as a fracture parameter in a real crack growth length meaning.

• KCI Concrete Journal
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• 제14권1호
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• pp.30-35
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• 2002

The fractal geometry is a non-Euclidean geometry which describes the naturally irregular or fragmented shapes, so that it can be applied to fracture behavior of materials to investigate the fracture process. Fractal curves have a characteristic that represents a self-similarity as an invariant based on the fractal dimension. This fractal geometry was applied to the crack growth of cementitious composites in order to correlate the fracture behavior to microstructures of cementitious composites. The purpose of this study was to find relationships between fractal dimensions and fracture energy. Fracture test was carried out in order to investigate the fracture behavior of plain and fiber reinforced cement composites. The load-CMOD curve and fracture energy of the beams were observed under the three point loading system. The crack profiles were obtained by the image processing system. Box counting method was used to determine the fractal dimension, D$_{f}$. It was known that the linear correlation exists between fractal dimension and fracture energy of the cement composites. The implications of the fractal nature for the crack growth behavior on the fracture energy, G$_{f}$ is apparent.ent.

• Architectural research
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• 제16권4호
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• pp.175-183
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• 2014

Contemporary architecture tends to deconstruct modern architecture based on rationalization just like reductionism and functionalism and secedes from it. It means change from mechanical to organic and ecological view of the world. According to these changes, consideration of a compositive relationship presented variety and complexity in architecture. Thus, the modern speculation based on rationalism cannot provide an alternative interpretation about complicated architectural phenomena. At this point in time, the purpose of this study is to investigate the possibilities of the fractal as an alternative tool of analysis and design in contemporary architecture. In this study, two major aspects are discussed. First, the fractal concepts just like 'fractal dimension', 'box-counting dimension' and 'fractal rhythm' can be applied to analysis in architecture. Second, the fractal formative principles just like 'scaling', 'superimposition trace', 'distortion' and 'repetition' can be applied to design in architecture. Fractal geometry similar to nature's patterned order can provide endless possibilities for analysis and design in architecture. Therefore further study of fractal geometry should be conducted synthetically from now on.

• 한국안전학회지
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• 제17권4호
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• pp.38-44
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• 2002

The application of fractal concept provides an useful method in the study for the quantitative analysis of irregular variations like the fracture surfaces and crack profiles. Fractal curves have characteristics that represents a self-similarity based on the fractal dimension. The fractal dimensions were obtained by the box counting method. In this report, we obtained the nearly stable fractal dimensions of fracture crack profiles for STS316 with CT specimen as the crack advances and the relationships between crack length and fractal dimension. Moreover fractal fracture parameter that corresponds to J-R curve is shown by the relationships between fractal dimension and crack extension. From the results, we concluded that crack extension of high toughness material also shows the fractal characteristics, which can be used in order to evaluate the crack life precisely.

• 한국안전학회지
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• 제13권4호
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• pp.71-78
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• 1998

Real crack and fracture surfaces have irregularities producing zigzag contours. These irregularities are analysed by a fractal geometry which has been by a Mandelbrot. We obtained a fractal dimension which is one of the fractal characteristics. It is also estimated by an vertical section method that fractal characteristics in the fractured surfaces can be obtained as the crack grows. Moreover fractal fracture energy that corresponds to an energy release rate is shown to find relationships between fractal dimensions and crack behaviors. From these results, we concluded that a fractal characteristics analysis for a crack can be applied to a fracture mechanics.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제9권2호
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• pp.91-105
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• 2002

The study of fractal hedgehogs is a recent development in the ambit of fractal theory and nonlinear analysis. The intent of this paper is to present a study of fractal hedgehogs along with some of their special constructions. The main result is a new fractal hedgehog theorem. As a consequence, a fractal projective hedgehog theorem of Martinez-Maure is obtained as a special case, and several fractal hedgehogs and similar images are discussed.

• 대한기계학회논문집B
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• 제26권1호
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• pp.18-26
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• 2002

With the introduction of Fractal notation, various fields of engineering adopted fractal notation to express characteristics of geometry involved and one of the most frequently applied areas was turbulence. With research on turbulence regarding the surface as fractal geometry, attempts to analyze turbulent premised flame as fractal geometry also attracted attention as a tool for modeling, for the flame surface can be viewed as fractal geometry. Experiments focused on disclosure of flame characteristics by measuring fractal parameters were done by researchers. But robust principle or theory can't be extracted. Only reported modeling efforts using fractal dimension is flame speed model by Gouldin. This model gives good predictions of flame speed in unstrained case but not in highly strained flame condition. In this research, approaches regarding fractal dimension of flame as one representative value is pointed out as a reason for the absence of robust model. And as an extort to establish robust modeling, Presents methods treating fractal dimension as statistical variable. From this approach flame characteristics reported by experiments such as Da effect on flame structure can be seen quantitatively and shows possibility of flame modeling using fractal parameters with statistical method. From this result more quantitative model can be derived.

• 한국기계가공학회지
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• 제5권1호
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• pp.7-12
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• 2006

Recently, the fractal interpolation methods have been widely introduced and used to estimate and analyze various theoretical and experimental data. Because of the chaotic behaviors of dynamic cutting force data, some method for end-milling force analysis must be used. The fractal analysis used in this paper is fractal linear interpolation and fractal dimension. Also, several methods for computing fractal dimensions have been used in which the fractal dimension of the typical dynamic end-milling force was calculated according to number of data points that are generally lower than 200 data points sampled. This fractal analysis shows a possible prediction of end-milling force that has some dynamic chatter property or stationary property in endmilling operation.