• Title/Summary/Keyword: FRACTAL method

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Goal Regulation Mechanism through Reinforcement Learning in a Fractal Manufacturing System (FrMS) (프랙탈 생산시스템에서의 강화학습을 통한 골 보정 방법)

  • Sin Mun-Su;Jeong Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.05a
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    • pp.1235-1239
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    • 2006
  • Fractal manufacturing system (FrMS) distinguishes itself from other manufacturing systems by the fact that there is a fractal repeated at every scale. A fractal is a volatile organization which consists of goal-oriented agents referred to as AIR-units (autonomous and intelligent resource units). AIR-units unrestrictedly reconfigure fractals in accordance with their own goals. Their goals can be dynamically changed along with the environmental status. Since goals of AIR-units are represented as fuzzy models, an AIR-unit itself is a fuzzy logic controller. This paper presents a goal regulation mechanism in the FrMS. In particular, a reinforcement learning method is adopted as a regulating mechanism of the fuzzy goal model, which uses only weak reinforcement signal. Goal regulation is achieved by building a feedforward neural network to estimate compatibility level of current goals, which can then adaptively improve compatibility by using the gradient descent method. Goal-oriented features of AIR-units are also presented.

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A study On the Image Coding Based on the Segmented Fractal Coding (세그멘트기법을 이용한 프랙탈 영상 부호화에 대한 연구)

  • Seo, Ju-Ha;Choi, Hwang-Kyu;Cho, Churl-Hee
    • Journal of Industrial Technology
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    • v.15
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    • pp.93-101
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    • 1995
  • Fractal coding is a promising method for image compression, but it has not lived up to its promise as low bit-rate image compression scheme. The existing algorithms for finding self-mapping contractive transforms are computationally expensive and offer a poor rate-quality tradeoff. In this paper, we propose a segment based fractal coding. We classify the range blocks into shade, midrange or edge blocks, and segment edge block along the edge. And we apply midrange coding scheme for each segment. Our experiments show that our method gives better rate-qualty trade of than current fractal block coding methods.

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Creation of Fractal Images with Rotational Symmetry Based on Julia Set (Julia Set을 이용한 회전 대칭 프랙탈 이미지 생성)

  • Han, Yeong-Deok
    • Journal of Korea Game Society
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    • v.14 no.6
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    • pp.109-118
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    • 2014
  • We studied the creation of fractal images with polygonal rotation symmetry. As in Loocke's method[13] we start with IFS of affine functions that create polygonal fractals and extends the IFS by adding functions that create Julia sets instead of adding square root functions. The resulting images are rotationally symmetric and Julia set shaped. Also we can improve fractal images by modifying probabilistic IFS algorithm, and we suggest a method of deforming Julia set by changing exponent value.

A study of Fractal Image Compression with HV partition (HV 분할 방식을 이용한 fractal 영상 압축에 관한 연구)

  • Lee, Moon-Jik;Chung, Chin-Hyun
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2240-2242
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    • 1998
  • Image coding based on fractal theory presents highly compressed image. In this paper, we discuss about compression of Image using HV partition method. HV partition scheme devides the image adaptively in horizontal and vertical axis. And for reducing the enconding time for the domain-range comparison, we use classification scheme, which uses the order of brightness of the rectangular portion of the image. This paper focused on the technique to reduce coding time which is a problem in traditional fractal compression by adaptive selection of image and its classification method.

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Fast Fractal Image Compression Using DCT Coefficients and Its Applications into Video Steganography (DCT계수를 이용한 고속 프랙탈 압축 기법과 화상 심층암호에의 응용)

  • Lee, Hye-Joo;Park, Ji-Hwan
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.1
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    • pp.11-22
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    • 1997
  • The fractal image compression partitions an original image into blocks of equal size and searches a do-main block having self-similarity. This method of compression achieves high compression ratio because it is unnecessary to transmit the additional codebook to receiver and it provides good quality of reconstructed images. In spite of these advantages, this method has a drawback in which encoding time increase due to a complicated linear transformation for determining a similar-domain block. In this paper, a fast fractal image compression method is proposed by decreasing the number of transformation usings AC(alternating current) coefficients of block. The proposed method also has a good quality as compared with the well-known fractal codings. Furthermore, method also has a good quality as apply the video steganography that can conceal an important secret data.

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Changes in the fractal dimension of peri-implant trabecular bone after loading: a retrospective study

  • Mu, Teh-Jing;Lee, Dong-Won;Park, Kwang-Ho;Moon, Ik-Sang
    • Journal of Periodontal and Implant Science
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    • v.43 no.5
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    • pp.209-214
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    • 2013
  • Purpose: To assess bony trabecular changes potentially caused by loading stress around dental implants using fractal dimension analysis. Methods: Fractal dimensions were measured in 48 subjects by comparing radiographs taken immediately after prosthesis delivery with those taken 1 year after functional loading. Regions of interest were isolated, and fractal analysis was performed using the box-counting method with Image J 1.42 software. Wilcoxon signed-rank test was used to analyze the difference in fractal dimension before and after implant loading. Results: The mean fractal dimension before loading ($1.4213{\pm}0.0525$) increased significantly to $1.4329{\pm}0.0479$ at 12 months after loading (P<0.05). Conclusions: Fractal dimension analysis might be helpful in detecting changes in peri-implant alveolar trabecular bone patterns in clinical situations.

APLICATION OF FRACTAL DIMENSION ESTIMATION ALGORITMS TO EVALUATING HUMAN SKIN STATE

  • Araghy, Ali Parchamy;Sato, Mie;Kasuga, Masao
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.655-658
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    • 2009
  • Fractal dimension has been used for texture analysis as it is highly correlated with human perception of surface roughness and applied to quantifying the structures of wide range of objects in biology and medicine. On the other hand, the evaluation of the human skin state is based solely on the subjective assessment of clinicians; this assessment may vary from moment to moment and from rater to rater. Therefore we attempt to analysis of skin texture image using fractal dimension and discuss its application to evaluating human skin state. It can be helpful for extracting human features and also can be useful for detection of many human skin diseases. This paper presents a method to calculate fractal dimension of skin with use of camera lens magnification. We take multiple pictures frequently from skin with different camera lens magnification as a magnification factor of fractal set, and counting the number of objects (cells) in each picture as a number of self similar pieces of fractal set.

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A Study on the Enhancement of Image Distortion for the Hybrid Fractal System with SOFM Vector Quantizer (SOFM 벡터 양자화기와 프랙탈 혼합 시스템의 영상 왜곡특성 향상에 관한 연구)

  • 김영정;김상희;박원우
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.41-47
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    • 2002
  • Fractal image compression can reduce the size of image data by the contractive mapping that is affine transformation to find the block(called as range block) which is the most similar to the original image. Even though fractal image compression is regarded as an efficient way to reduce the data size, it has high distortion rate and requires long encoding time. In this paper, we presented a hybrid fractal image compression system with the modified SOFM Vector Quantizer which uses improved competitive learning method. The simulation results showed that the VQ hybrid fractal using improved competitive loaming SOFM has better distortion rate than the VQ hybrid fractal using normal SOFM.

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A Study on the Characteristics of Organic Expression in Contemporary Architecture with Fractal Geometry (프랙탈 기하학을 활용한 현대건축의 유기적 표현특성에 관한 연구)

  • Roh, Jeong-Ha;Lee, Kuen-Taek;Hong, Hyun-Jin
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.4
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    • pp.25-36
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    • 2019
  • Contemporary architecture is showing its deconstruction and departure from modern architecture based on rationality, such as reductionism or virtualism. This means a shift from a mechanistic and ecological world view to an organic and ecological view, from a deterministic reason to a reason for a possible secret static. This study examines the potential of fractals, a scientific theory of complexity that is emerging as a new paradigm in the 21st century, as an appropriate alternative to contemporary complexity architecture. The method and scope of this study were understood and its features were identified through literature and data research and prior study review. Based on the organic nature of fractal geometry, we analyzed the works of contemporary architects(Frank Gehry, Bernard Tschumi, Steven Holl, Zaha Hadid, Rem Koolhaas, Daniel Libeskind, Zvi Hecker, Ito Toyo) and studied the possibility of architectural design using the principle of fractal. As a result, fractal geometry, similar to the patterned order of nature, has an infinite set of organizational functionalities in architecture and can be applied in various aspects of design analysis. Architectural designs based on the fractal theory will require more research and development to realize dynamic design representation using digital computers.

Fractal Approaches to Ecological and Limnological Phenomena (생태학적 ${\cdot}$ 육수학적 현상들에 대한 프랙탈의 적용)

  • Chang, Hyun-Jeong;Kang, Sin-Kyu;Lee, Do-Won
    • Korean Journal of Ecology and Environment
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    • v.33 no.2 s.90
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    • pp.69-79
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    • 2000
  • Fractal geometry has become one of prospective research approaches as the complex structure of natural entities is not easily characterized by traditional Euclidean geometry. With the fractal geometry, we can better decipher the complex structure and identify natural and anthropogenic agents of landscape patterns occurring at different spatial scales. The usefulness of fractal, however, has not been fully appreciated among Korean academic societies, especially in ecological and limnological fields. We attempt to address three points in this study. First, we introduce the concept and dimension of fractal and review relevant research approaches, especially with respect to ecological and limnological phenomena. Second, we explore possible applications of fractal to some aspects of geography and land use characteristics in South Korea. For the analyses of fractal dimensions, we used data published in other studies previously and collected for this study. Data were analyzed by a perimeter/area method of fractal dimension for the spatial distribution of global solar radiation and leaf area index, and the movement of wild boars in forested landscapes of mid-eastern Korea. The same approach was also applied to the water channel of a hypothetical river and the shape of reservoirs in Yongin, Kyunggi Province. Finally, we discuss the results and key issues to consider when a fractal approach is employed in ecology and limnology.

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