• 제목/요약/키워드: Chaos Theory

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라벤더 향 자극에 대한 EEG 생체신호의 비선형 분석 (A Study on EEG bionic signals management for using the non-linear analysis methods)

  • 강근;안광민;이형
    • 한국정보기술응용학회:학술대회논문집
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    • 한국정보기술응용학회 2002년도 추계공동학술대회 정보환경 변화에 따른 신정보기술 패러다임
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    • pp.461-467
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    • 2002
  • 뇌에서 얻은 시계열 신호들은 대부분 불규칙하고 복잡한 파형을 가지고 있으며, 1980년대 중반까지만 해도 이러한 신호들은 확률론 과정(stochastic process)으로 발생된 '소음'(noise)으로 여겨졌다. 하지만 최근 들어 뇌에 관한 연구가 활발히 진행되었고 EEG를 이용한 생체신호의 비선형분석에 관한 연구가 진행되면서 뇌에서 발생되는 신호는 의미 있는 신호로 분석되어지고 있다. 이에 비선형 분석방법인 상관차원을 이용하여 라벤더 향기 전과 향기 후의 뇌파의 변화를 분석하고, 주파수 대역별로 delta파, theta파, alpha파, beta파로 나누어서 라벤더 향이 뇌에 미치는 영향을 분석한다. 즉, 뇌에서 발생되는 신호의 특징을 찾기 위해 다른 향보다 강하게 반응하는 라벤더 향을 후각자극으로 제시하여 EEG를 측정한 후, 16채널에 대한 상관차원을 구하고 라벤더 향이 뇌에 미치는 영향을 분석한다.

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청각자극의 반송 주파수에 따른 뇌전위 신호의 해석 (The Analysis of EEG Signal Responding to the Pure Tone Auditory Stimulus)

  • 최정미;배병훈;김수용
    • 대한의용생체공학회:의공학회지
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    • 제15권4호
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    • pp.383-388
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    • 1994
  • 일정한 단속 주파수(triggering frequency)를 지닌 청각자극의 반송 주파수(carrier ferquency, pure tone)를 1kHz에서 3kHz까지 0.5kHz단위로 증가시키면서, 이에 반응하는 뇌전위를 디지탈 EEG측정장치를 이용하여 총 7초 동안 1kHz의 sampling frequency로 컴퓨터로 전송하였다. 먼저 신호의 pseudo-phase space분석을 통해 뇌전위의 진폭특성을 파악하였다. 이러한 해석은 생리학적으로 밝져진 소리의 반송주파수와 소리의 크기 인지사이의 상관관계와 잘 일치함이 확인되었다. 또한 이 신호외 Lyapunov exponent 분석을 통해 신호의 발산 특성을 물리적으로 파악하고, 이러한 특성을 이미 여러가지 접근법에 의해 밝혀져 있는 생리학적 실험결과와 관련지어 해석함으로써 반송 주파수에 반응하는 뇌의 mechanism을 뇌전위 측정에 의해서 검출이 가능함을 확인할 수 있었다.

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라벤더 향 자극에 대한 EEG 생체신호의 비선형 분석 (A Study on EEG bionic signals management for using the non-linear analysis methods)

  • 강근;안광민;이형
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2002년도 추계공동학술대회
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    • pp.461-467
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    • 2002
  • 뇌에서 얻은 시계열 신호들은 대부분 불규칙하고 복잡한 파형을 가지고 있으며, 1980년대 중반까지만 해도 이러한 신호들은 확률론 과정(stochastic process)으로 발생된 '소음'(noise)으로 여겨졌다. 하지만 최근 들어 뇌에 관한 연구가 활발히 진행되었고 EEG를 이용한 생체신호의 비선형 분석에 관한 연구가 진행되면서 뇌에서 발생되는 신호는 의미 있는 신호로 분석되어지고 있다. 이에 비선형 분석방법인 상관차원을 이용하여 라벤더 향기 전과 향기 후의 뇌파의 변화를 분석하고, 주파수 대역별로 delta파, theta파, alpha파, beta파로 나누어서 라벤더 향이 뇌에 미치는 영향을 분석한다. 즉, 뇌에서 발생되는 신호의 특징을 찾기 위해 다른 향보다 강하게 반응하는 라벤더 향을 후각 자극으로 제시하여 EEG를 측정한 후, 16채널에 대한 상관차원을 구하고 라벤더 향이 뇌에 미치는 영향을 분석한다.

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An Assessment of Records Management Practice in Selected Local Government Councils in Ogun State, Nigeria

  • Bakare, Abdullahi A.;Abioye, Abiola A.;Issa, Abdulwahab Olanrewaju
    • Journal of Information Science Theory and Practice
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    • 제4권1호
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    • pp.49-64
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    • 2016
  • What government does/fails to do is conveyed to the public largely by records and information of various types in the public service, without which there will be no government. When records are poorly managed, much time is involved in sorting and locating needed information from large volumes of records. The rate of records misplaced or lost from which useful information for decision making is usually obtained makes it difficult to provide concise and up-to-date records of both past and present operations, raising the challenge of effective record-keeping. Thus this study examined records management practices in selected local government councils in Ogun State, Nigeria, adopting the descriptive survey research method using questionnaires for data collection. Its population comprised 415 records of personnel in the selected councils, of which 208 were sampled using simple random technique. From the 208 copies of the questionnaire administered on the registry personnel, 150 copies were useable, with a 72.12% response rate. Descriptive statistics were used for the analysis. The results indicated a prevalence of paper as the dominant medium for recording/conveying information in the councils with most of these being either in active state, semi-active, and vital and were kept and maintained in the registry, while in-active records were kept in the records store. Storage facilities for record-keeping were insufficient. Security measures against unauthorized access to records were by restrictions and subject users to managerial clearance. The study concluded that council records were in chaos and recommended the formulation of coherent records management policy, adequate budgetary provision, and adequate finance.

시간지연과 입력포화를 갖는 T-S 퍼지 카오스 시스템의 동기화 (Synchronization of T-S Fuzzy Chaotic System with Time-Delay and Input Saturation)

  • 김재훈;신현석;김은태;박민용
    • 전자공학회논문지SC
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    • 제42권1호
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    • pp.13-21
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    • 2005
  • 본 논문에서는 시간지연과 입력포화를 갖는 카오스 시스템에 대한 퍼지 모텔 기반의 동기화 기법을 제안한다. 시간지연을 갖는 카오스 마스터 시스템과 슬레이브 시스템을 모델링하기 위해 Takagi-Sugeno(T-S) 퍼지 모델을 이용한다. 특히 슬레이브 시스템은 제어 입력이 제한되는 입력포화 특성을 갖는다고 가정한다. 선형 오차 피드백과 병렬 분상 보상(PDC) 방법에 따라 퍼지 카오스 동기화 시스템을 설계하고 동기화 오차 시스템의 국소 안정도 조건을 해석한다. 신호 전송 채널에는 시간지연이 항상 존재하므로 채널 시간지연 또한 고려한다. 입력포화와 시간지연을 갖는 퍼지 동기화 시스템의 국소 안정도에 대한 충분 조건은 Lyapunov-Krasovskii 이론을 적용하여 선형 행렬 부등식 (LMI) 문제의 해를 통해 얻어진다. 제안된 동기화 기법의 효과를 확인하기 위해서 모의 실험을 수행한다.

由 《漂海録》 看中国文化传承的分析 (Thorough Analysis of Chinese Cultural Heritage Based on Pyohaerok)

  • 최창원
    • 산업진흥연구
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    • 제1권2호
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    • pp.121-128
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    • 2016
  • Cultural heritage means a great lot to a nation's social system and its people's behavior consciousness and plays an important role in its self-development and improvement. It is essential for a nation's self-education and renewal. Improper cultural heritage will be disastrous because it may fall a nation into a loss of terrible chaos. Only the proper cultural heritage can make it always self-awaking, self-correcting and remaining vital in life. This paper, from the perspective of Choi Bu's Pyohaerok, makes a thorough analysis of the unbalance heritage of Chinese ancient culture for thousands of years. For example, many fine traditions gradually vanished in our actual life or only take half their life in heritage nowadays, such as our ancient broad and profound Confucian etiquette, ancient exquisite brocade art and architecture, ancient advanced ship-building technology and many other advanced numerous technological inventions; however, too much unwanted cultural rubbish keeps constant prevailing and takes repeated successions in the life, such as the heavy-form-and-light-content management mode, borrowing power to do evil, neglecting technological inventions long time and generally believing in ghost theory,etc.. This paper mainly focuses on the partial successions of the bad cultural heritage and its bad influence on the country, and concludes that it is just that that makes the country more and more backward. Therefore, the paper makes some pondering over these issues and proposes some related ideas of country-building to attract others participation to deal with them.

Wavelet Thresholding Techniques to Support Multi-Scale Decomposition for Financial Forecasting Systems

  • Shin, Taeksoo;Han, Ingoo
    • 한국데이타베이스학회:학술대회논문집
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    • 한국데이타베이스학회 1999년도 춘계공동학술대회: 지식경영과 지식공학
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    • pp.175-186
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    • 1999
  • Detecting the features of significant patterns from their own historical data is so much crucial to good performance specially in time-series forecasting. Recently, a new data filtering method (or multi-scale decomposition) such as wavelet analysis is considered more useful for handling the time-series that contain strong quasi-cyclical components than other methods. The reason is that wavelet analysis theoretically makes much better local information according to different time intervals from the filtered data. Wavelets can process information effectively at different scales. This implies inherent support fer multiresolution analysis, which correlates with time series that exhibit self-similar behavior across different time scales. The specific local properties of wavelets can for example be particularly useful to describe signals with sharp spiky, discontinuous or fractal structure in financial markets based on chaos theory and also allows the removal of noise-dependent high frequencies, while conserving the signal bearing high frequency terms of the signal. To date, the existing studies related to wavelet analysis are increasingly being applied to many different fields. In this study, we focus on several wavelet thresholding criteria or techniques to support multi-signal decomposition methods for financial time series forecasting and apply to forecast Korean Won / U.S. Dollar currency market as a case study. One of the most important problems that has to be solved with the application of the filtering is the correct choice of the filter types and the filter parameters. If the threshold is too small or too large then the wavelet shrinkage estimator will tend to overfit or underfit the data. It is often selected arbitrarily or by adopting a certain theoretical or statistical criteria. Recently, new and versatile techniques have been introduced related to that problem. Our study is to analyze thresholding or filtering methods based on wavelet analysis that use multi-signal decomposition algorithms within the neural network architectures specially in complex financial markets. Secondly, through the comparison with different filtering techniques' results we introduce the present different filtering criteria of wavelet analysis to support the neural network learning optimization and analyze the critical issues related to the optimal filter design problems in wavelet analysis. That is, those issues include finding the optimal filter parameter to extract significant input features for the forecasting model. Finally, from existing theory or experimental viewpoint concerning the criteria of wavelets thresholding parameters we propose the design of the optimal wavelet for representing a given signal useful in forecasting models, specially a well known neural network models.

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Wavelet Thresholding Techniques to Support Multi-Scale Decomposition for Financial Forecasting Systems

  • Shin, Taek-Soo;Han, In-Goo
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 1999년도 춘계공동학술대회-지식경영과 지식공학
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    • pp.175-186
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    • 1999
  • Detecting the features of significant patterns from their own historical data is so much crucial to good performance specially in time-series forecasting. Recently, a new data filtering method (or multi-scale decomposition) such as wavelet analysis is considered more useful for handling the time-series that contain strong quasi-cyclical components than other methods. The reason is that wavelet analysis theoretically makes much better local information according to different time intervals from the filtered data. Wavelets can process information effectively at different scales. This implies inherent support for multiresolution analysis, which correlates with time series that exhibit self-similar behavior across different time scales. The specific local properties of wavelets can for example be particularly useful to describe signals with sharp spiky, discontinuous or fractal structure in financial markets based on chaos theory and also allows the removal of noise-dependent high frequencies, while conserving the signal bearing high frequency terms of the signal. To data, the existing studies related to wavelet analysis are increasingly being applied to many different fields. In this study, we focus on several wavelet thresholding criteria or techniques to support multi-signal decomposition methods for financial time series forecasting and apply to forecast Korean Won / U.S. Dollar currency market as a case study. One of the most important problems that has to be solved with the application of the filtering is the correct choice of the filter types and the filter parameters. If the threshold is too small or too large then the wavelet shrinkage estimator will tend to overfit or underfit the data. It is often selected arbitrarily or by adopting a certain theoretical or statistical criteria. Recently, new and versatile techniques have been introduced related to that problem. Our study is to analyze thresholding or filtering methods based on wavelet analysis that use multi-signal decomposition algorithms within the neural network architectures specially in complex financial markets. Secondly, through the comparison with different filtering techniques results we introduce the present different filtering criteria of wavelet analysis to support the neural network learning optimization and analyze the critical issues related to the optimal filter design problems in wavelet analysis. That is, those issues include finding the optimal filter parameter to extract significant input features for the forecasting model. Finally, from existing theory or experimental viewpoint concerning the criteria of wavelets thresholding parameters we propose the design of the optimal wavelet for representing a given signal useful in forecasting models, specially a well known neural network models.

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로버트 스미슨의 "개간 프로젝트"에 나타나는 생태학적 세계관 (The Ecological View of Robert Smithson's Reclamation Project)

  • 이재은
    • 미술이론과 현장
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    • 제15호
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    • pp.7-30
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    • 2013
  • This is a study on the ecological view of Robert Smithson's reclamation projects. Smithson was a pioneer of Earth art in the late 1960's. Robert Smithson believed that he could transform industrial wastelands, such as an abandoned oil rig and a no longer used quarry, into "Earth Art." In the early seventies, he conceived of land reclamation as a new art form and called this art "Reclamation Projects." His attention regarding industrial ruin started from the American political and social situations in the 1960's. In the late 1960's, American society was in chaos from the right of movement of African Americans, the women's rights movement and from the strike for renunciation of the Vietnam War. The intellectual class seemed to believe that it was the destiny of a closed system's society to run in the direction of entropy. Smithson, who was skeptical about the system of American society, also thought that entropy was the proper diagnosis to describe America's situation in the 1960's. The 1960's civic movements like the civil rights movement and antiwar movements expanded into the environmental movements based on ecological views of the 1970's. The government had also started to worry about environmental pollution. Thus, the reclamation act was also established in 1972. Smithson believed that the relation between art and social background are closely related and affect each other. He was concerned with how art can join society, and the result was reclamation projects. Such reclamation projects lie on man-made wastelands, like abandoned oil rigs and no longer used quarries, which was an allegory of entropy. He also thought that Frederick Law Olmsted was a pioneer of earth art. The aesthetic category of Olmsted's view of landscape is to be based on the picturesque of Uvedale Price and William Gilpin. So Smithson, who considered Olmsted as his touchstone, also accepted the picturesque. Such reclamation projects aim to change with nature by adapting the creative power of artists to the ruin which has the highest level of entropy in industrial society. Smithson wanted this to become the bridge between man and nature. His reclamation project's aim, which shows the system interacting between man and nature as a network, is not different from the ecological view of the 1970's environmental movement.

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현대패션에 표현된 하이브리드 경향 연구 - 1990년대 후반을 중심으로 - (A Study on Hybrid Expressed in Modern Fashion - Focusing on the End of 1990s -)

  • 임영자;한윤숙
    • 복식
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    • 제51권5호
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    • pp.113-134
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    • 2001
  • This study was carried out with an objective to prepare the framework of conformity for the 21st century modern fashion, which is interactive with mankind, based on a position that the 21st century contemporary fashion with its amalgamating trend of diversified artistic forms may not be elucidated on a standpoint centering on one certain modality. The hybrid fashion trend of historical modality which provides freedom and satisfaction in creation of an individuals expressive power in expressing true desire of mans inside through man-centered thought of the times has made multifarious motives of the past and present fragmentary. It thus extracts inner divisions and the concept of consolidation through three-dimensional form. Modern fashion is newly interpreted by the material and details of high technologies. and is harmonized by mix and match with various expressions. By having it, it is being expressed together with many types of dresses and ornaments. Modern fashion is being expressed together with many types of dresses and ornaments by new interpretations with the material and details of high technologies and by being harmonized with mix and match with various expressions. The hybrid fashion design trend of regional elements formed by stimuli and contacts of diverse local culture by globalization of network that was achieved by scientific technologies of the contemporary information society has disintegrated varied boundaries in the conventional culture by the latest communication technology-new media on the basis of newly created culture. The fact that regional elements could be expressed as if they were interrelated without each being deprived of originality may be explained with an interpretation on pluralism. The hybrid fashion design trend of cultural aspect, which manifests in the background of scientific technological culture as it transcends the societal-cultural boundaries based on the de-centralization theory of Frederic Jameson, has supplemented the imperfect meanings through conversional correlation with other forms and internal program changes. The middle stratal and polyhedral characteristics are seen as each cultural element is dismantled and reassembled by application of 'multiple-time point expression'. Design forming method is not to bring destruction from outside, but to embrace instability and chaos through radical dismantling of the inside. and to pursue diversity and openness. Thus. it is implemented by an approach that takes the role of design process. In communication of discontinuity, continuity was dismantled through forms of mixing, overlap, perversion, insertion and coincidence.

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