• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1481-1484
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• 1997

This paper describes a electrical tree simulation by fractal theory. Tree patterns produced by computer simulation with random numbers were studied from the point of view of fractal dimension. Tree patterns have a variety of shapes such as branch-like, bush-like, and quasi-bush-like trees. The patterns are determined by origins and probability ratio. The fractal dimensions have been measured a function of discharge number.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.521-527
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• 1997

Irregular shapes and growth behavior of surface micro-crack showed very complex and nonlinear propeties and many investigators have performed theoretical analysesand experiments on them to characterize fatigue strength. They had difficulties in estimating fatigue life due to random distribution, growth and coalescence of surface micro-cracks. The straightness of crack growth along intergranular and transgranular was prevented from irregular microstructure and precipitates. Euclid geometry can't quantify shape of surface micro-crack but ftractal geometry can. Therefore, it is suggested that average fractal dimension of surface micro-cracks is able to estimate fatigue life but fractal dimension of maximum surface micro-crack is not in Al 2024-T3 alloy.

• 대한기계학회논문집B
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• 제28권5호
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• pp.501-509
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• 2004

Unipolar diffusion charging of non-spherical particles was investigated for various particle shapes. We researched with TiO$_2$agglomerates produced by the thermal decomposition of titanium tetraisopropoxide (TTIP) vapor. TTIP was converted into TiO$_2$, in the furnace reactor and was subsequently introduced into the sintering furnace. Increasing the temperature in the sintering furnace, aggregates were restructured into higher fractal dimensions. The aggregates were classified according to their mobility using a differential mobility analyzer. The projection area and the mass fractal dimension of particles were measured with an image processing technique performed by using transmission electron microscope (TEM) photograph. The selected aggregates were charged by the indirect photoelectric-charger and the average number of charges per particle was measured by an aerosol electrometer and a condensation particle counter. For the particles of same mobility diameter, our results showed that the particle charge quantity decreases as the sintering temperature increases. This result is understandable because particles with lower fractal dimension have larger capacitance and geometric surface area.

• 한국시뮬레이션학회논문지
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• 제4권1호
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• pp.113-119
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• 1995

In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models have become popular for recreating a wide variety of the shapes found in nature, a specific 3D terrain model such as Uleung Island could not be formulated by statistical fractals easily owing to the random effects. However, by locating the midpoints on the edges and the surface of a specific terrain such as Uleung Island, a similar shape of the terrain model can be simulated. This paper shows the way of simulating 3D Uleung Island terrain model by the statistical fractals wherein the subdivision algorithm is used.

• 한국수자원학회논문집
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• 제32권5호
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• pp.565-577
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• 1999

프랙탈 기하학은 불규칙적이고 복잡한 자연 현상을 수학적으로 나타낼 수 있는 방법을 제시해 줄 수 있으며, 자기상사성을 가지고 있는 하천의 형상을 비롯한 하도망의 구성은 프랙탈 차원을 가지고 있는 프랙탈 현상이라 할 수 있다. GIUH란 유역의 수문학적 응답인 IUH에 하천의 지형학적인 특성을 적용한 강우-유출 모형으로, Horton의 차수비를 이용하여 지형학적인 특성을 반영할 수 있으며 하천 유역에서 프랙탈 차원은 길이비, 면적비, 분기비 등 Horton의 차수비를 이용하여 산정할수 있다. 프랙탈 GIUH 모형을 제시하였다. 프랙탈 GIUH 모형은 Rosso(1984)가 제시한 GIUH-Nash 모형의 형상계수와 규모계수 등의 매개변수 산정시 유역의 자기상사성을 대변할 수 있는 프랙탈 차원을 직접 적용하였으며, 하천의 길이비와 분기비 만의 함수로 나타내었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.245-252
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• 2002

The roughness of Joomoonjin sand and the Dongchun river sand was analysed by the fractal theory. It was found that the fractal dimension(D$\_$F/) of Joomoonjin sand is a little smaller than the Dongchun river sand. That means Joomoonjin sand is smoother than the Dongchun river sand. The measurements of D$\_$F/ of different fraction of the Donchun river sand showed that large particles were rougher than fine particles. The shapes of both sands were analysed by the Discrete Fourier Transform(DFT) and the Grid-based(GB) method. Normalization of coefficients with respect to size, starting point and its orientation made the coefficients invaried to these characteristics. The mean of the normalized coefficients was used to reconstruct the average shape for both sands, respectively. The measurements of the ellipticity ratio of different fraction of both sands showed that Joomoonjin sand is slightly flatter than the Dongcun river sand.

• 한국결정성장학회지
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• 제18권5호
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• pp.184-190
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• 2008

단순 침전법으로 타원, 땅콩, 아령, 바디가 있는 구형 모양의 $CaMoO_4$ 결정을 합성하였다. $Ca^{2+}$ 이온과 $MoO_4^{2-}$ 이온 농도가 증가함에 따라서 $CaMoO_4$의 형태는 차원형에서 땅콩 모양과 아령 모양을 거쳐서 마디가 있는 구형 모양으로 전개됨을 확인하였다. 이러한 $CaMoO_4$ 결정의 형태의 전개는 프랙탈 메커니즘에 기인한다. 타원형의 양 끝 부분에서부터 가지를 치면서 결정 성장이 시작된다. 1차와 2차 프랙탈 성장에 의해서 땅콩 모양과 아령 모양이 각각 형성되었다. 아령 모양에서 더 프랙탈 성장을 하여 최종적으로 마디가 있는 구형이 형성되었다.

• Structural Engineering and Mechanics
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• 제41권5호
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• pp.663-673
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• 2012

A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

• 패션비즈니스
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• 제21권5호
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• pp.136-150
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• 2017

3D printing has grown tremendously as the most noteworthy new technology in the manufacturing industries. In addition, the rapid development of computer science technology with 3D printing has created a new paradigm called Fractal Geometry, or a new form of digital art. This study explores the formative characteristics of 3D printing jewelry based on presentation of fractal geometry by classification of 3D printing jewelry's morphological types that except for producible shape with traditional mold manufacturing methods. The results of the study are as follows. The morphological characteristics of 3D printed jewelry are divided into their constitutive shapes by the repetition of the unit. The organic shape determined by superposition or overlapping, the systematic shape by distortion caused by distortion, and the variation in scaling by scaling. The formative characteristics, which are drawn from a study on the shape expression of 3D printed jewelry design using fractal geometry, consist of continuity, geometrical characteristics, and exaggeration. Continuity creates a new and self-assigned new space through a recursive structure through a cyclic structure that is formed along a single directional basis. The geometry of the geometry forms a three-dimensional and constructive structure comprised of the same size and structure of the same sized unit under the mathematical order of the geometry of Fractal's geometry. Exaggeration demonstrates the informal beauty and the maximization of the shape by expanding the scaling or superposition of a unit, by scaling the scale or he distortion of the units.

• 한국융합학회논문지
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• 제8권8호
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• pp.185-190
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• 2017

자연현상에서 발견되는 프랙털 (fractal) 구조는 자기 유사성 (self-similarity)의 반복된 형태로, 생명체의 발생과 기관 형성에서도 자주 관찰된다. 특히, 수많은 종류의 암모나이트에서 관찰되는 봉합선 (suture)의 복잡, 다양한 형태는 프랙털 생성에 대한 생물학적인 이해를 위한 좋은 연구소재이다. 본 연구에서는 희귀하게 초기 발생단계의 봉합선 구조가 매우 잘 보전된 Eogaudryceras sp.를 대상으로 봉합선 형성의 과정을 분석하고자 하였으며, 일반적으로 구하기 힘든 부위인 나선 (spiral) 중심부 1mm 이내의 현미경적인 관찰을 실시하였다. 아직 봉합선의 프랙털 구조 생성에 대한 생물학적인 기전은 아직 불분명한 상태이나, 본 연구를 통하여 암모나이트 발생초기에 프랙털 구조의 복잡성이 단계별로 분명한 차이가 있음을 발견하였다. 이러한 결과는 하나의 생명체 내에서 "Evo-Devo"의 여러 발생단계의 변화를 동시에 보여줄 수 있는 좋은 예시로서, 향후 프랙털 구조의 생물학적인 기전 연구 및 관련되는 다양한 융합학문에서의 접목과 활용이 기대된다.