• 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.

• 한국농공학회논문집
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• 제48권6호
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• pp.59-67
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• 2006

Particles of soil are crushed when soil is compacted in the in-situ or lab. Among many factors that affect the crush of particles, compaction energy is a major factor. Because the crush of particles can change physical properties, the analysis of effect of compaction energy is very important. In this study, the fragmentation fractals were used for determining the change in grain size distribution and the effect due to change in grain size distribution was estimated. Compaction energy was increased by 50, 100, 200 and 300% based on the energy of standard A compaction test. As a result, grain size distribution curves were changed and fine particles increased as compaction energy were increased. Relative compaction were ranged between $93.38{\sim}107.67$. Fractal dimension of each site increased as compaction energy increased. Relative compaction is proportional to the fractal dimension but coefficients of permeability were in inverse proportional to the involution of fractal dimension.

• 한국실내디자인학회논문집
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• 제15권5호
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• pp.52-59
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• 2006

Since the time of Vitruvius, the sciences have impacted on the perspectives for architecture and have had a direct influence on the shaping of built space. In recent years, architects have been looking again at sciences as a source of inspiration in the production of their designs and constructions. There are various ways to look at architecture's relationship to science. It is interesting to see how many of the words of day-to-day architectural speech have been drawn from science, the abundant use of references such as topology, fractals, chaos theory, and so on. The reasons for this may be obvious, insofar as science has become the dominant discourse of our times. The numerous attempts have been made to constitute architectural practice so as to bring it into line with the methods of science. But Alberto Perez-Gomez juxtaposed architectural theory and Husserl's. The Crisis of European Science. In Husserl's 'Crisis', it is modern science itself that is laid open question. Through examining its changing relationships to architectural ideas this paper is intended to describe the problematic relationship between science and architecture, in other words, architecture's as science.

• Structural Engineering and Mechanics
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• 제20권3호
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• pp.265-277
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• 2005

This paper is focused on fractal analysis of the surface cracking, a new tool for safety evaluation of corroded reinforced concrete (RC) beams. Comprehensive experimental investigations, including flexural tests, coupon tests on strength evaluation of corroded concrete and rusty rebar, and pullout tests to determine bond strength between concrete and rebar were carried out on nine Corroded Reinforced Concrete Beams (CRCB) exposed to an aggressive environment for more than 10 years. In combination with test results from a previous study on CRCBs fabricated in the laboratory from accelerated methods, it is found that, for both types of beams, the surface cracking distributions are fractal in character at loading and failure stages. Fractal dimension is calculated for all specimens at different corrosion states based on fractal analysis method. Relationships between the fractal dimension and mechanical properties of corroded concrete, rebar corrosion ratio, and ductility of CRCBs are discussed in detail. It is concluded that the fractal dimension can act as a damage index and can be efficiently used to describe the corrosion state of CRCBs.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1698-1701
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• 2006

In this research, fractal approach is applied to the realization of a virtual enterprise. Virtual enterprise is a temporarily built organization to cope with new business opportunity. It is composed of diverse business partners such as suppliers, manufacturers, customers, and service providers in value chains. Therefore, communication and interoperability problems between heterogeneous participants are one of the main concerns in developing collaboration models of a virtual enterprise. Fractal-based reference model can be a solution for this problem. The term 'fractal' is used to represent a participant of the value chains. There are many advantages when participants try to embody fractal-based collaboration model such as; (1) no restriction of inner configuration, (2) guarantee of autonomy, (3) easy implementation of interfaces, etc. Fractals are self-similar, however, this does not mean that they should have same configuration. In this paper, a fractal-based collaboration model for a virtual enterprise is proposed and described with (1) a formal formulation of fractal concept, (2) functional requirements and interfaces, and (3) a goal model as a driving force of the virtual enterprise.

• Wind and Structures
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• 제31권4호
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• pp.363-371
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• 2020

Proper understanding of offshore wind speed variability is of essential importance in practice, which provides useful information to a wide range of coastal and marine activities. In this paper, long-term wind speed data recorded at various offshore stations are analyzed in the framework of fractal dimension analysis. Fractal analysis is a well-established data analysis tool, which is particularly suitable to determine the complexity in time series from a quantitative point of view. The fractal dimension is estimated using the conventional box-counting method. The results suggest that the wind speed data are generally fractals, which are likely to exhibit a persistent nature. The mean fractal dimension varies from 1.31 at an offshore weather station to 1.43 at an urban station, which is mainly associated with surface roughness condition. Monthly variability of fractal dimension at offshore stations is well-defined, which often possess larger values during hotter months and lower values during winter. This is partly attributed to the effect of thermal instability. In addition, with an increase in measurement interval, the mean and minimum fractal dimension decrease, whereas the maximum and coefficient of variation increase in parallel.

• Imaging Science in Dentistry
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• 제36권2호
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• pp.69-72
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• 2006

Purpose : We evaluated the fractal dimension changes on bovine rib radiographs according to the decalcification degree and the exposure time in the bovine rib. Materials and Methods : Twenty 5 mm thick cross-sectional blocks from bovine rib bone were progressively decalcified in 30 mL 0.1 N hydrochloric acid for 5, 30, and 90 minutes. They were radiographed at three exposure time settings (0.22, 0.36, 0.43 mAs) before and after each decalcification stage. We selected $100{\times}100$ pixel-sized regions of interests (ROIs) on trabecular bone and calculated fractal dimensions by box-counting method. Results : Repeated measures ANOVA showed that fractal dimensions gradually decreased after acid-induced demineralization and with more exposure (P<0.001). Conclusion : The fact that fractal dimensions decrease after decalcification might support the hypothesis that patients with osteoporosis have decreased radiographic fractal dimension in trabecular bone in comparison to normal subjects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권2호
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• pp.96-100
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• 2012

Objectives: This study sought to evaluate trabecular changes in the mandible using fractal analysis and to explain the transient osteopenia related to rapid orthodontic tooth movement after orthognathic surgery. Materials and Methods: Panoramic radiographs were taken of 26 patients who underwent bilateral sagittal split ramus osteotomy. Radiographs taken before the surgery and 1 month after surgery were overlapped, and $40{\times}40$ pixel square regions of interest were selected near the mandibular canines and 1st molars. After the image processing procedure, the fractal dimension was calculated using the box-counting method. Results: Fractal dimension after orthognathic surgery decreased in a statistically significant manner (P<0.05). The change in fractal dimension on the canine side had greater statistical significance as compared to that seen on the 1st molar side. Conclusion: This study found that bone density decreases after orthognathic surgery due to transient osteopenia related to the regional acceleratory phenomenon. This result can provide a guide to evaluating orthodontic tooth movement after orthognathic surgery.

• 한국정보처리학회논문지
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• 제4권2호
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• pp.586-595
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• 1997

본 논문에서는 프렉탈과 신경망을 이용하여 등고선 데이타로부터 3차원 지형을 복원하는 더욱 개선된 알고리즘을 제안한다. 본 알고리즘은 이미 제안한 것[1, 2, 3]을 바탕으로 인접 패치들과의 관계를 고려하여 개선한 것으로, 지형의 특징을 좀더 사실 적으로 반영할 수 있는 더 많은 조건을 부여한 데이타를 기존의 특징 데이타에 부가하여 학습한다. 학습 결과 평균오차가 줄어든 학습 패턴을 이용하여 산악지형과 평탄지형 에 대하여 실험하고 결과 산악지형에 대한 적용이 더 효과적임을 보였다.

• 한국정보과학회논문지:시스템및이론
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• 제31권11호
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• pp.611-616
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• 2004

본 논문은 극소 원자블록(ultra small atomic block)에 공간예측(spatial prediction)을 적용하여 프랙탈(fractal) 영상압축의 압축시간을 획기적으로 향상시키고 화질/압축률을 향상시키는 방법을 제안한다. 본 방법은 치역(range block)의 크기가 아주 작으면 아주 적은 탐색범위 내에서 변환계수(transformation parameter)들의 값을 극히 제한하더라도 유사한 정의역(domain block)을 쉽게 찾을 수 있고 변환계수들이 좋은 상호관계를 유지함을 이용하여 변환계수 예측으로 화질/압축률을 향상시킨다. 특히, 본 방법은 탐색범위를 극히 제한하기 때문에 기존의 프랙탈 압축방법들 보다 압축시간을 획기적으로 향상시킨다.