• 전기학회논문지P
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• 제56권1호
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• pp.23-27
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• 2007

This article presents a review on chaos analysis of two-phase flow. Chaos theory has recently been applied to two-phase flow analysis, and it gives promising measures to quantitatively identify two-phase flow patterns and pool boiling behaviors. But, consistency of the calculated chaotic measures were not completely confirmed yet. More experimental data are requested for chaos analysis of two-phase flow. Also, chaos analysis methodology should be developed by experimental verification.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6621-6629
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• 2014

사회현상은 복잡한 변수들에 의해서 변화되고 있기 때문에 새로운 과학적 인식론과 방법론의 기초가 요구되며, 우리가 직면한 문제들을 분석하기 위해서는 패러다임 전환의 체계적 이해가 필요하다. 본 연구는 자연과학에서 발전시킨 카오스 이론을 제시하여 현대 사회의 비정상성을 논함으로써 카오스 패러다임의 중요성을 제안하였다. 카오스 이론은 정치, 경제, 그리고 사회학의 주제를 가로지르는 광범위하고 다양한 사회현상에도 적용된다. 사회과학 연구에서 카오스 이론을 유효적절하게 개발하고 응용한다면, 사회현상을 탐구하기 위한 방법론적 및 이론적 기초를 강화하기 위한 수단으로서 유용한 패러다임의 역할을 수행하게 될 것이다.

• Journal of information and communication convergence engineering
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• 제1권1호
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• pp.53-57
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• 2003

Chaos theory is a study researching the irregular, unpredictable behavior of deterministic and non-linear dynamical system. The interpretation using Chaos makes us evaluate characteristic existing in status space of system by tine series, so that the extraction of Chaos characteristic understanding and those characteristics enables us to do high precision interpretation. Therefore, This paper propose the new method which is adopted in extracting character features and recognizing characters using the Chaos Theory. Firstly, it gets features of mesh feature, projection feature and cross distance feature from input character images. And their feature is converted into time series data. Then using the modified Henon system suggested in this paper, it gets last features of character image after calculating Box-counting dimension, Natural Measure, information bit and information dimension which are meant fractal dimension. Finally, character recognition is performed by statistically finding out the each information bit showing the minimum difference against the normalized pattern database. An experimental result shows 99% character classification rates for 2,350 Korean characters (Hangul) using proposed method in this paper.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권2호
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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.

• Journal of Biosystems Engineering
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• 제25권2호
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• pp.123-130
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• 2000

A forcasting scheme for daily solar irradiance on agricultural field sis proposed by application of chaos theory to a long term observation data. It was conducted by reconstruction of phase space, attractor analysis, and Lyapunov analysis. Using the methodology , it was determined whether evolution of the five climatic data such as daily air temperature , water temperature , relative humidity, solar radiation, and wind speed are chaotic or not. The climatic data were collected for three years by an automated weather station at Hwasung-gun, Kyonggi-province. The results showed that the evolution of solar radiation was chaotic , and could be predicted. The prediction of the evolution of the solar radiation data was executed by using ' local optimal linear reconstruction ' algorithm . The RMS value of the predicting for the solar radiation evolution was 4.32 MJ/$m^2$ day. Therefore, it was feasible to predict the daily solar radiation based on the chaos theory.

• KIEE International Transactions on Power Engineering
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• 제4A권1호
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• pp.33-41
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• 2004

Knowledge of partial discharge (PD) is important to accurately diagnose and predict the condition of insulation. The PD phenomenon is highly complex and seems to be random in its occurrence. This paper indicates the possible use of chaos theory for the recognition and distinction concerning PD signals. Chaos refers to a state where the predictive abilities of a systems future are lost and the system is rendered aperiodic. The analysis of PD using deterministic chaos comprises of the study of the basic system dynamics of the PD phenomenon. This involves the construction of the PD attractor in state space. The simulation results show that the variance of an orthogonal axis in an attractor of chaos theory increases according to the magnitude and the number of PDs. However, it is difficult to clearly identify the characteristics of the PDs. Thus, we calculated the magnitude on an orthogonal axis in an attractor using singular value decomposition (SVD) and principal component analysis (PCA) to extract the numerical characteristics. In this paper, we proposed the condition monitoring method for gas insulated switchgear (GIS) using SVD for efficient calculation of the variance. Thousands of simulations have proven the accuracy and effectiveness of the proposed algorithm.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제7권2호
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• pp.87-100
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• 2000

In this paper, we try to approach chasos with numerical method. After investigating nonlinear dynamcis (chaos) theory, we introduce Lyapunov exponent as chaos\`s index. To look into the existence of chaos in 2-dimensional difference equation we computes Lypunov exponent and examine the various behaviors of solutions by difurcation map.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2004년도 춘계 학술발표대회 논문집
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• pp.112-113
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• 2004

• 한국언론정보학보
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• 제19권
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• pp.185-211
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• 2002

최근에 기존의 신문, 방송, 통신 등의 매체가 인터넷미디어로 융합돼 가는 현상이 활발히 이루어지고 있다. 본 연구는 이러한 매체융합 현상에 대한 이해를 시도한다고 할 때, 이 현상의 어떤 측면에 주목해야 하는지, 그리고 이를 어떤 이론으로 설명할 수 있는지 그리고 이러한 이론적 설명이 가능하다면 이것이 갖는 함의는 무엇인지를 알아보고자 하는 의도를 갖는다. 융합 현상을 설명하는 이론으로서는 현재 자연현상과 기술공학, 사회현상에 대한 새로운 이론적 관점으로 대두되고 있는 카오스 이론을 적용해 본 것이다. 연구 결과, 매체융합 현상은 상호 영향을 미치는 관련된 많은 행위주체들에 의해서 비선형적으로 그리고 공진화적으로 진행되어 가고 있음을 알 수 있었다. 과거의 수동적 수용자들도 매체 융합 현상에 의해서 능동적 참여자로서 그리고 구조적 맥락에서 주체로 구성되면서 역할이 변해 가고 있었다. 매체융합 현상에 카오스 이론을 적용해 본 결과, 사업자 또는 이용자들이 달라진 매체 환경에 적응라는 데 운용한 몇 가지 시사점을 얻을 수 있었다. 창발성 발현을 위해 카오스 상태를 유지하는 것이 유용하며, 미디어 시스템에 대한 거대 유기체적 시각과, 혼돈과 질서에 대한 군형 잡힌 사고를 유지하는 것이 중요하다는 점 등이 그것이다.

• 대한의용생체공학회:의공학회지
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• 제15권3호
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• pp.347-354
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• 1994

This paper describes a diagnostic protocol of nonlinear dynamic characteristics of biological system using chaos theory. An integrated chaos analysis system for the diagnosis of biological system was designed. We suggest a procedure of attractor reconstruction for reliable qualitative and quantitative analysis. The effect of autonomic nervous system activity on heart rate variability with power spectral analysis and its characteristics of chaotic attractors are investigated. The results show the applicability to evaluate the mental and physical conditions using nonlinear characteristics of biological signal.