• Title/Summary/Keyword: fractal system

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Crack Growth Behaviors of Cement Composites by Fractal Analysis

  • Won, Jong-Pil;Kim, Sung-Ae
    • KCI Concrete Journal
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    • v.14 no.1
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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.

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Automatic Composition Algorithm based on Fractal Tree (프랙탈 트리를 이용한 자동 작곡 방법)

  • Kwak, Sung-Ho;Yoo, Min-Joon;Lee, In-Kwon
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.618-622
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    • 2008
  • In this paper, we suggest new music composition algorithm based on fractal theory. User can define and control fractal shape by setting an initial state and production rules in L-System. We generate an asymmetric fractal tree based on L-System and probability. Then a music is generated by the fractal tree image using sonification techniques. We introduce two composition algorithm using the fractal tree. First, monophonic music can be generated by mapping x and y axis to velocity and pitch, respectively Second, harmonic music also can be generated by mapping x and y axis to time and pitch, respectively Using our composition algorithm, user can easily generate a music which has repeated pattern created by recursive feature of fractal, and a music which has structure similar to fractal tree image.

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Modeling and implementation of a fractal template for fractal manufacturing system (FrMS) (프랙탈 생산시스템을 위한 프랙탈 템플릿의 모델링 및 구현)

  • Mun, Jeong-Tae;Jeong, Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.471-474
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    • 2004
  • In order to quickly respond to the rapidly changing manufacturing environment, it is imperative for the system to have such capabilities as flexibility, adaptability, reusability, etc. One of the promising approaches for new manufacturing paradigm satisfying those capabilities is the fractal manufacturing system (FrMS). FrMS is based on the concept of autonomously cooperating and self-reconfigurable agents referred to as fractals. In this paper, a fractal template is proposed to have both fractal-specific and agent-specific characteristics and proper techniques for implementation are also selected. The proposed template can be easily extended to the platform of FrMS which supports simulation, shop flow control, and other research issues existed in the manufacturing systems. An example of applying the proposed template to the simulation is also presented.

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Plan-coordination architecture for Multi-agent in the Fractal Manufacturing System (FrMS) (프랙탈 생산 시스템에서의 멀티에이전트를 위한 플랜 조율 체계)

  • Cha, Yeong-Pil;Jeong, Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.1124-1128
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    • 2005
  • In this paper, a plan-coordination architecture is proposed for multi-agent control in the fractal manufacturing system (FrMS). A fractal in FrMS is a set of distributed agents whose goal can be achieved through cooperation, coordination, and negotiation with other agents. Since each agent in the FrMS generates, achieves, and modifies its own plan fragments autonomously during the coordination process with other agents, it is necessary to develop a systematic methodology for the achievement of global plan in the manufacturing system. The heterarchical structure of the FrMS provides a compromised plan-coordination approach, it compromise a centralized plan-generation/execution (which mainly focuses on the maximization of throughput) with a distributed one (which focuses on the autonomy of each module and flexibility of the whole system). Plan-coordinators in lower level fractal independently generate plan fragments according to the global plan of higher level fractal, and plan-coordinators in higher level fractal mediate/coordinate the plan fragments to enhance the global performance of the system. This paper assumes that generation method of the plan fragments and the negotiation policy of the fractal is achieved by a simple process, and we mainly focuses on the information exchanging and distributed decision making process to coordinate the combinations of plan fragments within a limited exchange of information.

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Fractal Dimension for Morphology Analysis of Rubbed Surface with Hydraulic Members

  • Cho, Yon-Sang;Seo, Young-Baek;Park, Heung-Sik
    • KSTLE International Journal
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    • v.3 no.2
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    • pp.75-78
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    • 2002
  • The surface morphology of oil-lubricated surfaces fer hydraulic piston motors is believed to be extremely effective in contact mechanics, adhesion, friction and weak In order to describe morphology of various rubbed surfaces on driving conditions, the wear test was carried out under different experimental conditions in an oil-lubricated system. And fractal descriptors were applied to rubbed surfaces of hydraulic members and analyzed through an image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimensions can be determined by sum of intensity difference of surface pixel. The morphology of rubbed surfaces can be effectively obtained by fractal dimension.

The Pattern Recognition System Using the Fractal Dimension of Chaos Theory

  • Shon, Young-Woo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.15 no.2
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    • pp.121-125
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    • 2015
  • In this paper, we propose a method that extracts features from character patterns using the fractal dimension of chaos theory. The input character pattern image is converted into time-series data. Then, using the modified Henon system suggested in this paper, it determines the last features of the character pattern image after calculating the box-counting dimension, natural measure, information bit, and information (fractal) dimension. Finally, character pattern recognition is performed by statistically finding each information bit that shows the minimum difference compared with a normalized character pattern database.

Goal model for the fractal-based SCM (프랙탈 기반 공급망 관리를 위한 골 모델)

  • O Seung-Jin;Cha Yeong-Pil;Jeong Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.05a
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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.

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Fractal evaluation of the level of alligator cracking in pavements

  • Vallejo, Luis E.
    • Geomechanics and Engineering
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    • v.4 no.3
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    • pp.219-227
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    • 2012
  • Pavement management systems require systematic monitoring of pavement surfaces to determine preventive and corrective maintenance. The process involves the accumulation of large amounts of visual data, typically obtained from site visitation. The pavement surface condition is then correlated to a pavement distress index that is based on a scoring system previously established by state or federal agencies. The scoring system determines if the pavement section requires maintenance, overlay or reconstruction. One of the surface distresses forming part of the overall pavement distress index is the Alligator Crack Index (AC Index). The AC Index involves the visual evaluation of the crack severity of a section of a pavement as being low, medium, or high. This evaluation is then integrated into a formula in order to obtain the AC Index. In this study a quantification of the visual evaluation of the severity of alligator cracking is carried out using photographs and the fractal dimension concept from fractal theory. Pavements with low levels of cracking were found to have a fractal dimension equal to 1.051. Pavements with moderate levels of cracking had a fractal dimension equal to 1.1754. Pavements with high degrees of cracking had a fractal dimension that varied between 1.5037 (high) and 1.7111 (very high). Pavements with a level of cracking equal to 1.8976 represented pavements that disintegrated and developed potholes. Thus, the visual evaluation of the state of cracking of a pavement (the AC Index) could be enhanced with the use of the fractal dimension concept from fractal theory.

Application of Fractal Dimension for Rubbed Surface Morphology of Hydraulic Members

  • Luy, M.R.;Jun, S.J.;Cho, Y.S.;Park, H.S.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.257-258
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    • 2002
  • The surface morphology of oil-lubricated surface for hydraulic piston motor is believed to be extremely effective in contact mechanics. adhesion. friction and wear. In order to describe morphology of various rubbed surface on driving condition, the wear test was carried out under different experimental conditions in oil-lubricated system. And fractal descriptors was applied to rubbed surface of hydraulic members with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. Morphology of rubbed surface can be effectively obtained by fractal dimension.

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Characteristics of Tree Propagation & Fractal Dimension in Modified Epoxy Resin System (개질된 에폭시 수지계에서 트리진전과 프랙탈 차원의 특성)

  • 안현수;박수길;이홍기;심미자;김상욱
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.305-308
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    • 1997
  • Characteristics of tree propagation and fractal dimension in DGEBA/MDA/GN system were investigated. In the GN contents of 0 and 5 phr, tree was not produced. In the GN content of 10 phr, a reversed sigmoidal behaviour was found but in those of 15 and 20 phr, linear behaviors were found. All electrical trees possessed fractal characteristics. Fractal dimensions of epoxy resin system were almost constant with the variation of observation angles. Since dielectric breakdown occurred earlier in the GN content of 20 phr, fractal characteristics of modified epoxy resin system in a particular term couldnt be investigated.

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