• Title, Summary, Keyword: attractor

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Construction of Attractor Simulator for Cutting Characteristics Evaluation of Non-Ferrous Metals (비철금속의 절삭성 평가를 위한 어트랙터 시뮬레이터의 구축)

  • 고준빈;윤인식
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.1
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    • pp.63-69
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    • 2003
  • This study proposes the construction of attractor simulator for cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, cutting force and surface roughness are measured by tool dynamometer. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. Constructed attractor in this study can be used for cutting characteristics evaluation of non-ferrous metals

Defect evaluations of weld zone in rails using attractor analysis (어트랙터 해석을 이용한 레일 용접부의 결함 평가)

  • 민경주;나성훈;권성태;임성진;윤인식
    • Proceedings of the KSR Conference
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    • pp.87-95
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    • 1998
  • This study proposes the analysis and evaluation method of time series ultrasonic signal using the attractor analysis. Features extracted from time series signal analyze quantitatively characteristics of welding defects. For this purpose, analysis objective in this study is fractal dimension and attractor Quadrant feature. Trajectory changes in the attractor indicated that even the same type of defects carried substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange. Such differences in characteristics of weld defects enables the evaluation of unique features of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hale) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimensions. Proposed attractor feature extraction in this study can enhance the precision rate of ultrasonic evalaution for defect signals of rail weld zone such as side hole and crack.

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Construction of Attractor System by Integrity Evaluation of Polyethylene Piping Materials (폴리에틸렌 배관재의 건전성 평가를 위한 어트랙터 시스템의 구축)

  • Taik, Hwang-Yeong;Kyu, Oh-Seung;Won, Yi
    • Proceedings of the KSME Conference
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    • pp.609-615
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    • 2001
  • This study proposes analysis and evaluation method of time series ultrasonic signal using attractor analysis for fusion joint part of polyethylene piping. Quantitatively characteristics of fusion joint part is analysed features extracted from time series. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. These differences in characteristics of fusion joint part enables the evaluation of unique characteristics of fusion joint part. In quantitative fractal feature extraction, feature values of 4.291 in the case of debonding and 3.694 in the case of bonding were proposed on the basis of fractal dimensions. In quantitative quadrant feature extraction, 1,306 point in the case of bonding(one quadrant) and 1,209 point(one quadrant) in the case of debonding were proposed on the basis of fractal dimensions. Proposed attractor feature extraction can be used for integrity evaluation of polyethylene piping material which is in case of bonding or debonding.

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Multiple Attractor CA Based Pattern Classifier (다중 끌개를 갖는 셀룰라 오토마타를 이용한 패턴 분류기 생성)

  • Hwang, Yoon-Hee;Cho, Sung-Jin;Choi, Un-Sook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.3
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    • pp.315-320
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    • 2010
  • Classifying multi-class pattern plays an important role in grouping of records in database systems, detection of faults in the VLSI circuits and so on. In this paper, we propose an algorithm for the construction of multi-class pattern classifier with minimum memory capacity using MACA(Multiple Attractor Cellular Automata) and the subspace concept for given multi-class patterns.

Defect evaluations of weld zone in rails using attractor analysis (어트랙터 해석을 이용한 레일 용접부의 결함 평가)

  • Yi, Won;Yun, In-Sik;Kwon, Sung-Tae
    • Journal of the Korean Society for Railway
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    • v.2 no.1
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    • pp.38-46
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    • 1999
  • This study proposes the analysis and evaluation method of time series ultrasonic signal using the attractor analysis. Features extracted from time series signal analyze quantitatively characteristics of weld defects. For this purpose, analysis objective in this study is fractal dimension and attractor quadrant feature. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange even though the types of defects are identified. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hole) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimensions. Proposed attractor feature extraction in this study can enhance the precision rate of ultrasonic evaluation for defect signals of rail weld zone such as side hole and crack.

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Construction of 2-3 Dimensional Attractor System for Cutting Characteristics Evaluation of Metals (금속의 절삭성 평가를 위한 2-3차원 어트랙터 시스템의 구축)

  • Yun In Sik;Lee Jong Dae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.2
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    • pp.8-13
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    • 2005
  • This study proposes the construction of 2-3 dimensional attractor system for cutting characteristics evaluation of metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, using diamond turning machine to perform cutting processing, by measuring cutting force and surface roughness and according to cutting conditions the aluminum about cutting properties. Trajectory changes in the attractor indicated a substantial difference in attractor characteristics. Constructed 2-3 dimensional attractor system in this study can be used for cutting characteristics evaluation of metals.

D1-MACA based Two-Class Pattern Classifier (D1-MACA 기반의 두 클래스 패턴 분류기)

  • Hwang, Yoon-Hee;Choi, Un-Sook;Cho, Sung-Jin
    • The Journal of the Korea institute of electronic communication sciences
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    • v.3 no.4
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    • pp.254-259
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    • 2008
  • Two with the shunt which classifies with the class which is divided D1-MCA(Depth 1 Multiple Attractor Cellular Automata) proposes pattern gathering which comes to give from this dissertation. This time attractor valence 2 makes become with the method will be able to minimize the memory quantity the condition of pattern gathering will be able to compose D1-MACA analyzes classification crossroad bitterly the method which composes D1-MACA the concept of subspace and uses composes efficiently.

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Weak attractors and Lyapunov-like functions

  • Kim, Jong-Myung;Kye, Young-Hee;Lee, Keon-Hee
    • Communications of the Korean Mathematical Society
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    • v.11 no.2
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    • pp.457-462
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    • 1996
  • Recently Hurley [3] proved that if A is a weak attractor of a discrete dyanamical system f then there exists a Lyapunov-like function for A. The purpose of this note is to study whether the converse of the above result does hold or not.

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ATTRACTORS OF LOCAL SEMIFLOWS ON TOPOLOGICAL SPACES

  • Li, Desheng;Wang, Jintao;Xiong, Youbing
    • Journal of the Korean Mathematical Society
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    • v.54 no.3
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    • pp.773-791
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    • 2017
  • In this paper we introduce a notion of an attractor for local semiflows on topological spaces, which in some cases seems to be more suitable than the existing ones in the literature. Based on this notion we develop a basic attractor theory on topological spaces under appropriate separation axioms. First, we discuss fundamental properties of attractors such as maximality and stability and establish some existence results. Then, we give a converse Lyapunov theorem. Finally, the Morse decomposition of attractors is also addressed.