• Title/Summary/Keyword: FRACTAL

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Spectral and Nonlinear Analysis of EEG in Various Age Groups (뇌파의 연령별 스펙트럼 및 비선형적 분석)

  • Joo, Eun-Yeon;Kim, Eung-Su;Park, Ki-Duck;Choi, Kyoung-Gyu
    • Annals of Clinical Neurophysiology
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    • v.3 no.1
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    • pp.31-36
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    • 2001
  • Background & Objectives : Fractal Dimension(FD) could be an index of correlation between variable parameters in non-linear chaotic signals. We tried to demonstrate that EEG wave is compatible with chaotic waves by measuring the Lyapunov exponent index and compared the difference of FD between variable age groups(teens, 30's, 50's) Methods : We estimated the Lyapunov exponent index and the FD from digital EEG data among five persons in each normal age groups by using the software which is programmed in our laboratory. Statistical analysis was done with SPSS win 8.0. The statistical differences of Lyapunov exponent index and FD between each electrodes and each age groups were done with ANOVA and paired sample t-test. Result : The Lyapunov exponent indexes were larger than 1 in each electrode and age group. There is no statistical difference in FD between each electrodes and each age groups. Except in 30th age group. In this group the FD of right hemisphere is larger than that of left hemisphere. Conclusion : The result of Lyapunov exponent index means EEG wave is a non-linear chaotic signal. And the results of FD suggest that chaotic parameters of right hemisphere is larger than those of left hemisphere at rest at least in younger people. We think that chaotic parameters can be a useful tool in investigating the variable diseases or brain states.

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The Way to Create the Korean Low Carbon Green City through the Contemporary Interpretation of the Pungsu (풍수의 현대적 해석을 통한 한국형 녹색도시 조성 방안)

  • Park, Sung Dae
    • Journal of the Korean association of regional geographers
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    • v.20 no.1
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    • pp.70-91
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    • 2014
  • There have been a lot of efforts to adapt climate change around the world, and Korea is no exception. The low carbon green cities for overseas have had many different forms through their own special models and strategies. Korea needs a model and strategy of Korean low carbon green city, which is suitable for Korea climate and topography. This study pays attention to the Pungsu, which is Korean traditional thinking system for space, and examines the way for selecting locations and space planning to create the Korean low carbon green city through the contemporary interpretation of the Pungsu. For this purpose, first of all, this study makes efforts for the contemporary interpretation of the past Pungsu theory from the modern city's perspective, through understanding the difference between the Korea's historic villages(cities) and the modern cities. Based on the contemporary interpretation of the Pungsu theory, this study finds ways of application the system on selecting locations and space planning in the Pungsu theory to create the Korean low carbon green city.

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A Study on the Architectural Application of Biological Patterns (생물학적 패턴의 건축적 적용에 관한 연구)

  • Kim, Won Gaff
    • Korean Institute of Interior Design Journal
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    • v.21 no.2
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    • pp.35-45
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    • 2012
  • The development of digital media made the change of architectural paradigm from tectonic to the surface and pattern. This means the transition to the new kind of materiality and the resurrection of ornament. This study started as an aim to apply biological pattern to architectural design from the new perception of pattern. Architectural patterns in the early era appeared as ladders, steps, chains, trees, vortices. But since 21st century, we can find patterns in nature like atoms and molecular structures, fluid forms of dynamics and new geometrical pattern like fractal and first of all biological patterns like viruses and micro-organisms, Voronoi cells, DNA structure, rhizomes and various hybrids and permutations of these. Pattern became one of the most important elements and themes of contemporary architecture through the change of materiality and resurrection of ornament with the new perception of surface in architecture. One of the patterns that give new creative availability to the architectural design is biological pattern which is self-organized as an optimum form through interaction with environment. Biological patterns emerge mostly as self-replicating patterns through morphogenesis, certain geometrical patterns(in particular triangles, pentagons, hexagons and spirals). The architectural application methods of biological patterns are direct figural pattern of organism, circle pattern, polygon pattern, energy-material control pattern, differentiation pattern, parametric pattern, growth principle pattern, evolutionary ecologic pattern. These patterns can be utilized as practical architectural patterns through the use of computer programs as morphogenetic programs like L-system, MoSS program and genetic algorithm programs like Grasshoper, Generative Components with the help of computing technology like mapping and scripting.

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Implementation of Fog Effect on 3D Space Using 2D Image (2D 이미지를 활용한 3차원 공간상의 안개효과 구현)

  • Kim, jong-seong;Seo, young-sang;Park, Gyung-nam;Ryu, nam-hoon;Kim, eung-kon
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.889-893
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    • 2007
  • Now various research apply Fractal and chaos theory for natural expression of the fog on the fluid that the present this studies use special tools applicable are possible expression such as nature. But, ordinary peoples these works are much difficult yet easy to express, because require high prices and high professionals. Therefore, it is general assignments that everybody need easily expression of fog from high price special tools and professional programming reduction of complication difficult. Embodying this 2D image study made easily various image expression to be possible until UCC, individual from professional broadcasting. Specially, This study can use easily background fog expression when need to image expression such as Korean traditional pictures 3D because of possible expression of fog fluid effect in 3D space.

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Effects of Cognitive Task on Stride Rate Variability by Walking Speeds (보행속도변화에 따른 인지 과제 수행이 보행수 변동성에 미치는 영향)

  • Choi, Jin-Seung;Yoo, Ji-Hye;Kim, Hyung-Shik;Chung, Soon-Cheol;Yi, Jeong-Han;Lee, Bong-Soo;Tack, Gye-Rae
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.323-331
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    • 2006
  • The purpose of this study was to investigate the effect of performing a cognitive task during treadmill walking on the stride rate variability. Ten university students(age $24.0{\pm}0.25$, height $172{\pm}3.1cm$, weight $66{\pm}5.3kg$) were participated in dual task experiments which consist of both walking alone and walking with a cognitive task. Two-back task was selected for the cognitive task since it did not have learning effect during the experimental procedure.3D motion analysis system was used to measure subject's position data by changing walking speed with 4.8, 5.6, 6.4, 6.8, and 7.2 km/hr. Stride rate was calculated by the time between heel contact and heel contact. Accuracy rate of a cognitive task during walking, coefficient of variance, allometric scaling methods and Fano factor were used to estimated the stride rate variability. As the walking speed increased, accuracy rate decreased and the logarithmic value of Fano factor increased which showed the statistical difference. Thus it can be concluded that the gait control mechanism is distracted by the secondary attention focus which is the cognitive task ie. two-back task. Further study is needed to clarify this by increasing the number of subject and experiment time.

Toward Image: The politics of 'Non-representation' in contemporary art criticism (재현에서 이미지로: 현대 미술비평의 탈재현 전략)

  • Choi, Kwang-Jin
    • Journal of Science of Art and Design
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    • v.12
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    • pp.125-143
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    • 2007
  • The politics penetrating through the contemporary art since modernism to postmodernism is to accomplish the 'Non-representation' in the artworks. This study argues that postmodernism did not put an end to the formalistic feature of modernism but intended to accomplish it. Modernist art aimed at purity, i.e. self-referential and self-definition art advocated by Clement Greenberg, and it carne to the end by accomplishing flatness and materiality. It was an 'evasion to the matter' which allocated the object from visuality of outer object to the psychic image of the subject. It failed being 'non-representational' as what it really achieved was transition of object. Jean Baudrillard's theory tried to overcome the representational quality by 'being simulacre'. In the representative artworks of the past, the meaning of artworks was reverted under the outer context or object. The meaning again failed being 'Non-representational' as it was restored to the psychic image of the subject in modernist artworks where the definite illusion was demolished Meanwhile, artwork advocating simulacre acquired Non-representational quality by liberating from both models. It did not deconstruct the self-referential tendency of modernism but maximized the Non-representational modernistic principle. After creating 'Non-representation' through simulacre, the existential status and function of an artwork is the inclination and moral of contemporary art as 'Non-representation'. The image theory of Henri Bergson sets the existential status of 'image' as it does not belong to either subject nor object. It provides significant foundation for arguing the existential status of simulacre. Moreover, though an artwork as a fragment forming a movement image in the world cannot represent the object, it can however sustain certain kind of fractal resemblance with the world by letting the two parties communicate. The theory of sense by Gilles Deleuze is of profound significance as it specifically indicated way how the stage of absorption through the unity of subject and object is realized in forms of artworks, and configured the latent and invisible energy.

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Design of Film-Type Frequency Selective Surface Structure Based on Printed Electronic Technology to Implement Frequency-Selective Space in Buildings (건물 내 주파수 선택적 공간 구현을 위한 인쇄전자 기술 기반 필름형 주파수 선택 표면구조 설계)

  • Lee, In-Gon;Yoon, Sun-Hong;Hong, Ic-Pyo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.12
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    • pp.1007-1010
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    • 2017
  • In this paper, a frequency selective surface(FSS) with bandstop operation for radio-frequency spectrum management is presented. The proposed FSS is composed of patterns of fractal-based miniaturized unit cells for stable performance for angles of incidence and polarizations. For practical applications requiring high productivity and environmental compatibility, we fabricated a film-type FSS by screen-printing using Ag ink, rather than a conventional manufacturing method using a printed circuit board. To validate this study, we measured the transmission characteristics of the proposed FSS using the free-space measurement method, and observed the received strength of signal penetrating the FSS film applied to a wall.

Hierarchically porous carbon aerogels with high specific surface area prepared from ionic liquids via salt templating method

  • Zhang, Zhen;Feng, Junzong;Jiang, Yonggang;Feng, Jian
    • Carbon letters
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    • v.28
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    • pp.47-54
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    • 2018
  • High surface carbon aerogels with hierarchical and tunable pore structure were prepared using ionic liquid as carbon precursor via a simple salt templating method. The as-prepared carbon aerogels were characterized by nitrogen sorption measurement and scanning electron microscopy. Through instant visual observation experiments, it was found that salt eutectics not only serve as solvents, porogens, and templates, but also play an important role of foaming agents in the preparation of carbon aerogels. When the pyrolyzing temperature rises from 800 to $1000^{\circ}C$, the higher temperature deepens the carbonization reaction further to form a nanoporous interconnected fractal structure and increase the contribution of super-micropores and small mesopores and improve the specific surface area and pore volume, while having few effects on the macropores. As the mass ratio of ionic liquid to salt eutectics drops from 55% to 15%, that is, the content of salt eutectics increases, the salt eutectics gradually aggregate from ion pairs, to clusters with minimal free energy, and finally to a continuous salt phase, leading to the formation of micropores, uniform mesopores, and macropores, respectively; these processes cause BET specific surface area initially to increase but subsequently to decrease. With the mass ratio of ionic liquids to salts at 35% and carbonization temperature at $900^{\circ}C$, the specific surface area of the resultant carbon aerogels reached $2309m^2g^{-1}$. By controlling the carbonization temperature and mass ratio of the raw materials, the hierarchically porous architecture of carbon aerogels can be tuned; this advantage will promote their use in the fields of electrodes and adsorption.

A Study on the Application of 3D Digital Animation Model for Fashion Design I (3D 디지털 애니메이션 모델을 활용한 의상 시뮬레이션에 관한 연구 I)

  • 김혜영
    • Journal of the Korean Society of Costume
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    • v.50 no.2
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    • pp.97-109
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    • 2000
  • The purpose of this study is to apply 3D computer graphics in fashion design as a creative medium and it attempts to fine out what advantages 3D technique can offer to fashion design. For this purpose, this study, first, tries to develop a 3D digital model in which designer can select design, color , pattern and fabric palette whatever necessary . This study uses of the software named 'Poser of Fractal Design' and the and the 3D digital model comprises four stages ; body modeling, item design (item coordination), color design (color coordination), pattern and fabric design (pattern and fabric coordination). Secondly, this study seeks to accumulate a data base which was produced in the course of case studies, which have applied 3D digital model to design. The outcome of the case studies shows that 3D digital model can enhance designing in the following four aspects. ⅰ) It can give more freedom to designer to try various ideas, revise and modify them, It can also produce random generation. Through this process, the designer test various input and output without damage on fabric after revision and alteration. ⅱ) It can help designers to enhance their accuracy. Since fault in the design developed by the 3D digital model can be detected in advance, designers can make correlation before actual work begins. In the end, designers can express their ideas and intention accurately as well as freely. ⅲ) Since design developed by the 3D digital model can be shared on screen by various actors in the course of priduction such designers , merchandisers, and supervisors, it can help communication between and cut the time of feedback.ⅳ) By using the 3D digital model, designers can work from the begining with awareness of actual outcome their design, since the 3D digital model provide animation, which helps designers to envisage visual changes as they apply various items, colors, pattern and fabrics.

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The Quantitative Evaluation of Catchment Plan-Form Elongation (집수평면의 신장도에 대한 정량적 평가)

  • Kim, Joo-Cheol;Lee, Sang-Jin;Noh, Joon-Woo
    • Journal of Korea Spatial Information System Society
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    • v.11 no.3
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    • pp.1-8
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    • 2009
  • In this study the concepts on the elongation, compactness and equivalent ellipse of catchment plan-forms are applied to the real basins considering their theoretical frameworks. The catchment plan-forms and corresponding equivalent ellipses, obtained from GIS, are inspected on downstream directions. As a result the catchment plan-forms seem to be the population of the basin shapes which come from the random interaction between two conjectures on Hack's law being controversial recently. The ratio of the maximum and minimum inertia moments of the catchment plan-form Ri is more sensitive to evaluate the elongation of the basin shapes than the ratio of the main channel length and diameter of circle which has the same area as the catchment plan-form E. The catchment plan-forms compactness measures show distinct aspects according to their different definitions. These results are caused by the difficulties to quantification of the shapes and the composite consideration with more than two compactness measures and the fractal analysis are therefore required to recover them.

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