• 한국산업정보학회논문지
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• 제6권4호
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• pp.75-80
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• 2001

본 논문에서는 복잡한 하이퍼카오스 신호를 발생시키는 HVPM(Hyperchaotic Volume Preserving Maps) 모델을 이용한 카오스 동기화 알고리즘을 제안하고자 한다. 제안한 HVPM 모델은 3차원 이산시간(discrete-time) 연립 차분방정식으로 구성되어 있으며, 비선형 사상(maps)과 모듈러(modulus) 함수를 사용하여 랜덤한 카오스 어트랙터(attractor)를 발생시킨다. Pecora와 Caroll은 최근 카오스 시스템이 카오스 신호를 이용하여 동기화가 가능하다고 보고하였다. 따라서 본 논문에서는 하이퍼카오스 신호를 발생시키는 HVPM 모델간의 동기화를 위하여 결합동기(coupled synchronization) 알고리듬을 제안하였다. 모의실험에서 카오스 시스템과 하이퍼카오스 신호를 결합하여 카오스 동기화 현상을 확인할 수 있었다.

• 대한기계학회논문집A
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• 제29권10호
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• pp.1289-1297
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• 2005

The flow in a microchannel is usually characterized as a low Reynolds number (Re) so that good mixing is quite difficult to be achieved. In this regard, we developed a novel chaotic micromixer, named Serpentine Laminating Micromixer (SLM) in the present study, Part 1. In the SLM, the higher level of chaotic mixing can be achieved by combining two general chaotic mixing mechanisms: splitting/recombination and chaotic advection. The splitting and recombination (in other term, lamination) mechanism is obtained by the successive arrangement of 'F'-shape mixing units in two layers. The chaotic advection is induced by the overall three-dimensional serpentine path of the microchannel. Chaotic mixing performance of the SLM was fully characterized numerically. To compare the mixing performance, a T-type micromixer which has the same width, height and length of the SLM was also designed. The three-dimensional numerical mixing simulations show the superiority of the SLM over the T-type micromixer. From the cross-sectional simulation results of mixing patterns, the chaotic advection effect from the serpentine channel path design acts favorably to realize the ideal lamination of fluid flow as Re increases. Chaotic mixing mechanism, proposed in this study, could be easily integrated in Micro-Total-Analysis-System, Lab-on-a-Chip and so on.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권4호
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• pp.242-248
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• 2007

This paper analyzes on the chaos characteristics of the chaotic neural networks and presents the convergence condition. Although the transient chaos of neural network sould be beneficial to overcome the local minimum problem and speed up the learning, the permanent chaotic response gives adverse effect on optimization problems and makes neural network unstable in general. This paper investigates the dynamic characteristics of the chaotic neural networks with the chaotic dynamic neuron, and presents the convergence condition for stabilizing the chaotic neural networks.

• 한국산업정보학회논문지
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• 제4권3호
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• pp.90-94
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• 1999

디지틀 의사 랜덤변환의 출력이 같은 랜덤성을 갖는 것을 방지하기 위해서 카오스적인 처리과정이라 부르는 보다 랜덤하고, 결정론적인 변환과정을 소개하였다. 카오스적인 변환과정을 거치면, 카오스적인 랜덤순서가 발생하는 데, 이 카오스 변환은 결정론적 카오스함수를 기본으로 설계하였으며, 쉬프트 레지스터와 같은 간단한 하드웨어로 구현할 수 있었다. 본 논문에서는 쉬프트 레지스터로 구현한 카오스변환 회로를 제시하였고, 제시한 회로의 카오스적인 거동은 카오스 거동을 갖는 톱니함수 특성으로 설명하였다.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.686-691
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• 2012

In this paper, we designed a Chua's chaotic circuit using transcondcutor based nonlinear resistor. Proposed chaotic circuit consist of L, C, R and transcondcutor based Chua's diode. We performed SPICE simulation for chaotic dynamics such as time seriesform, frequency analysis and phase plane of the circuit. Chaotic dynamics of the circuit was analysed according to MOS size variation of the operational transconductance amplifier. Also, we performed SPICE circuit analysis for temperature dependance of the circuit. SPICE results showed that chaotic dynamics of the circuit varied according to the temperature variation and chaotic signals were generated in specific temperature conditions.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권4호
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• pp.322-331
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• 2014

Chaotic dynamics is an active area of research in biology, physics, sociology, psychology, physiology, and engineering. This interest in chaos is also expanding to the social scientific fields such as politics, economics, and argument of prediction of societal events. In this paper, we propose a dynamic model for addiction of tobacco. A proposed dynamical model originates from the dynamics of tobacco use, recovery, and relapse. In order to make an addiction model of tobacco, we try to modify and rescale the existing tobacco and Lorenz models. Using these models, we can derive a new tobacco addiction model. Finally, we obtain periodic motion, quasi-periodic motion, quasi-chaotic motion, and chaotic motion from the addiction model of tobacco that we established. We say that periodic motion and quasi-periodic motion are related to the pre-addiction or recovery stage, respectively. Quasi-chaotic and chaotic motion are related to the addiction stage and relapse stage, respectively.

• 소음진동
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• 제7권3호
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• pp.489-498
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• 1997

In this paper, chaotic motions of a curved pipe conveying oscillatory flow are theoretically investigated. The nonliear partial differential equation of motion is derived by Newton's method. The transformed nonlinear ordinary differential equation is a type of Hill's equation, which has the external and parametric excitation with a same frequency. Bifurcation curves of chaotic motion of the piping systems are obtained by applying Melnikov's method. Numerical simulations are performed to demonstrate theoretical results and show the strange attractor of the chaotic motion.

• East Asian mathematical journal
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• 제24권1호
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• pp.67-79
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• 2008

In this paper, we characterize the chaotic operator order $A\;{\gg}\;C\;{\gg}\;B$. Consequently all other possible characterizations follow easily. Some satellite theorems of the Furuta inequality are naturally given. And finally, using results of characterizing $A\;{\gg}\;C\;{\gg}\;B$, and by the Douglas's majorization and factorization theorem we are able to characterize the chaotic operator order $A\;{\gg}\;B$ in terms of operator equalities.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.693-696
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• 1999

This paper presents an analysis of the chaotic behavior in the discrete-time chaotic generator fabricated by CMOS technology. An approximated empirical equation is extracted from the measurement data of a nonlinear function block. Then the bifurcation diagram and Lyapunov exponent and time waveforms and frequency responses of the chaotic generator are calculated and simulated. And results of experiments in the chaotic circuit with the $\pm$2.5V power supply and clock rate of 10KHz are shown, and analysed.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.294-297
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• 1996

This paper proposes the method to recognize of time series data based on the chaotic feature extraction. Features extract from time series data using the chaotic time series data analysis and the pattern recognition process is using a neural network classifier. In experiment, EEG(electroencephalograph) signals are extracted features by correlation dimension and Lyapunov experiments, and these features are classified by multilayer perceptron neural networks. Proposed chaotic feature extraction enhances recognition results from chaotic time series data.