• Title/Summary/Keyword: Chaos System

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The Study of Compatibility for Method of Analysis of Nonlinear Characteristics of Blood Flow of Peripheral in Rabbit (토끼에 있어서 말초혈류운동의 비선형특성분석방법의 적합성에 관한 연구)

  • 남상희;최준영;이상훈
    • Progress in Medical Physics
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    • v.8 no.1
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    • pp.75-82
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    • 1997
  • The human physiological systems are so complex and irregular dynamics. Dynamics of peripheral blood vessel, in particular, have quite sensitive and complex. Before, the linear analytic method have been used to analyze the system. But, the method have many problems to predict the following results. In the other hand, the nonlinear analytic method, chaotic time series analysis method, is suitable for measuring complex, vary system. In this study, the scalar data of the blood flow of peripheral blood vessel of rabbits, in accordance with injection of glucose, was obtained and redefined as multi-dimensional vectors, with time-series analytic methods. This study also intended to confirm that the peripheral blood flow is chaotic dynamics and evaluate the availability of non-linear analytic method. As a result, the existing FFT, and mean could show the difference of blood flow of peripheral blood vessel by injection of glucose, but the nonlinear analytic method could show the definite difference. The hemodynamics is a chaotic phenomenon.

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A Security Design for a Smart Power Grid Field Test based-on Power IT Systems (전력 IT 기반스마트 파워그리드 실증 보안 체계 설계)

  • Lee, Myung-Hoon;Bae, Si-Hwa;Son, Sung-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.11
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    • pp.2497-2506
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    • 2010
  • Smart power grid is targeting to improve grid operation by integrating existing power IT technologies in the jeju smart grid field test. Real-time two-way communication and interoperability in power grid are essential to smart power grid. Adopting smart grid will increase security vulnerabilities in power grid by increasing the number of wireless sensors and the chances of the external exposure of communication networks. In addition, hackers can cause chaos in the power grid system with eavesdropping and forgery attacks in communication networks. Smart power grid is one of the most important systems in deploying smart grid, and it is important to design security system systematically since smart grid can be seriously damaged when problem occurs. In this paper, local and global smart grid security standard and security vulnerabilities in power grid are reviewed, and 2 level smart grid service model is proposed.

DOB-based piezoelectric vibration control for stiffened plate considering accelerometer measurement noise

  • Li, Shengquan;Zhao, Rong;Li, Juan;Mo, Yueping;Sun, Zhenyu
    • Smart Structures and Systems
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    • v.14 no.3
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    • pp.327-345
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    • 2014
  • This paper presents a composite control strategy for the active suppression of vibration due to the unknown disturbances, such as external excitation, harmonic effects and control spillover, as well as high-frequency accelerometer measurement noise in the all-clamped stiffened plate. The proposed composite control action based on the modal approach, consists of two contributions including feedback part and feedforward part. The feedback part is the well-known PID controller, which is widely used to increase the structure damping and improve its dynamic performance close to the resonance frequencies. In order to get better performance for vibration suppression, the weight matrixes is optimized by chaos sequence. Then an improved disturbance observer (IDOB) as the feedforward compensation part is developed to enhance the vibration suppression performance of PID under various disturbances and uncertainties. The proposed IDOB can simultaneously estimate the various disturbances dynamically as well as measurement noise acting on the system and suppress them by feedforward compensation design. A rigorous analysis is also given to show why the IDOB can effectively suppress the unknown disturbances and measurement noise. In order to verify the proposed composite control algorithm (IDOB-PID), the dSPACE real-time simulation platform is used and an experimental platform for the all-clamped stiffened plate active vibration control system is set up. The experimental results demonstrate the effectiveness, practicality and strong anti-disturbances ability of the proposed control strategy.

The Revision of Sajik Ritual System during the early Ming Dynasty and the Debates about National Sajik Altar Alteration during the early Joseon Dynasty (명 초 사직단 제도 개정과 조선 초 사직단 논쟁)

  • Baik, So-Hun
    • Journal of architectural history
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    • v.24 no.5
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    • pp.21-32
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    • 2015
  • Sajik, the altar of land and grain was treated as one of the most important national ritual facilities by the Joseon dynasty and the Ming dynasty because it symbolized the legitimacy of a dynasty, and its architectural ordonnance was arranged strictly by the government. But when the Joseon government considered to reconstruct its national Sajik altar in Hanyang during the Sejong period, they found the new architectural ordonnance for local Sajik altars recorded in "Hongwulizhi(洪武禮制)" had been published by the Ming government was hard to adopt, because it was too narrow and totally different from the traditional style. Above all things, they doubt of there was other architectural ordonnance for kingdoms, not for local governments. King Sejong ordered to investigate the origin form and former examples, and tried to get other ritual documents of authority published by the Ming government such as "Damingjili(大明集禮)". After several academic researches and intense debates, they decided to create a new architectural ordonnance for their national Sajik altar, its form was in accord with the traditional style and its size was in accord with the new ordonnance. But they did not know there had already been the architectural ordonnance for the kingdom in the Ming dynasty. Because the first emperor of the Ming dynasty had changed its Sajik ritual system several times, even the whole country of the Ming dynasty also had gone through chaos on this issue even after his death. Consequentially, the official documentation works had been made partially, there was no a complete document on this issue even in the Ming government.

A Study on Characteristics of Modern Planned City's Form and Space in the 1950s -Focused on two planned cities realized: Chandigarh and Brasilia- (1950년대 근대계획도시의 도시형태 및 공간적 특성에 관한 연구 - 찬디가르와 브라질리아 계획도시를 중심으로 -)

  • Kim, Jin-Mo;Park, Yeol
    • KIEAE Journal
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    • v.16 no.4
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    • pp.55-62
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    • 2016
  • Purpose: Since the 19th century many concrete models and theories for the ideal city had been proposed and in some way had affected on the ideal urban plans in the 20th century. Modern cities in the 20th century faced a total chaos, due to the world war and new social paradigm came from the development of technology. These social context leads us to be interested in ideal city. And two planned cities; Chandigarh, India and Brasilia, Brasil, are meaningful as the result of the modern ideal city in the early 20th century even though they completed just in part. Method: This study is focused on the characteristics of the modern ideal city in the early 20th century based on comparison with two realized cities. There are similarities and differences in their background, concept, and the characteristics of form and space. Result: First, both cities are required to make monumental and symbolic images by political issues. For this, Le Corbusier proposed the grid system for a metaphorical city and L. Costa defined the urban form with abstract axis for a mythological city. Second, the administrative districts in both cities are planned as symbolic places by formative buildings and their hierarchical arrangement. For neighbourhood unit 'Sector' in Chandigarh and 'Superquadras' in Brasilia are used for the neighbourhood unit respectively. Third, the car-oriented road system and urban environment by population overcrowding in tow cities are criticized in common. Consequently, as we can see, the modern ideal city in the early 20th century succeeds in making symbolic urban image, but exposes the limitation of sustainability.

Virtual Costume Creation Simplification Service Design - Focusing on Metaverse and ZEPETO - (가상 의상 제작 간략화 서비스 설계 - 메타버스, 제페토를 중심으로 -)

  • Ryu, Sang-Hyun;Sur, Da-Eun;Kim, Kyeong-Mok;Ban, Jae-Eun;Huh, Won-Whoi
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.583-589
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    • 2022
  • Due to COVID-19, which has thrown the whole world into chaos, it has become an era where many technologies and contents are made non-face-to-face. At the same time, the popularity of the metaverse service is also increasing day by day, and the virtual costume (avatar) industry, one of the sub-industries, is also growing. In this study, we designed and developed a system for creating virtual costumes to be uploaded to ZEPETO, a mobile metaverse service. Unlike the existing service that requires a program that operates in a PC environment, it can be produced only by shooting and simple operation through a mobile device. With the advantage of being able to process all tasks of this system in a mobile environment, small businesses and individual operators who are not familiar with external programs will be able to more easily access the 3D virtual clothing industry.

Beliefs About Gifted Education and Classroom Practices of the Science Teachers at Science Academy in Korea (과학영재학교 과학교사들의 영재교육에 대한 신념과 교수활동 유형)

  • Kim, Kyung-Jin;Kwon, Byung-Doo;Kim, Chan-Jong;Choe, Seung-Um
    • Journal of The Korean Association For Science Education
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    • v.25 no.4
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    • pp.514-525
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    • 2005
  • The most important factor in providing education to gifted students as well as to students in general are the teachers themselves. However, at present in Korea, most of the teachers in charge of education for the gifted are educated by in-service training programs only for a short period of time. It is doubtful whether the teachers, who have taught ordinary students in general, can teach gifted students effectively only after completing such a short course. This research investigated the relationship between the teachers' beliefs about educating the gifted and the teachers' classroom practices in a Science Academy through case studies. The guiding questions for this study are as follows: First, what beliefs do the participating teachers have about education for the gifted? Second, how are the participants' beliefs reflected in their classroom practices? Of the five participants, two are physics teachers, two are biology teachers, and one is an earth science teacher. I observed and videotaped four classroom practices for each participant and conducted an in-depth interview with each participant. Further data were collected through e-mails with the participants. All data were carefully transcribed and analyzed. The results are as follows: Beliefs about education for the gifted do not exist independently, and form a belief system connecting with beliefs about teaching and learning, and subject matter. And the belief systems of participants can be divided into "student-centered," "teacher-centered," and "conflict chaos." In the classes of the participants who have "student-centered" belief system, students' questions or opinions played an important role and the participation structure in the classroom was determined by the students. On the contrary, participants who have "teacher-centered" belief system focused on teaching contents as much as possible in their classes. These teachers played a heavy role and formed a participation structure where students depended on their teacher's intellectual authority and therefore participated in their class passively. A participant who have "conflict chaos" belief did not form a firm belief system yet, and traditional beliefs about teaching and learning were reflected a lot in her classes. The research results imply teachers' beliefs play an important role in classroom practices and beliefs about teaching and learning and subject matter as well as beliefs about education for the gifted are important factors for teachers who guide gifted students. Additionally, I make some suggestions for the improvement of teacher education for the gifted.

Application of Chaotic Analysis to Electroencephalography : Preliminary Study (혼돈 이론을 이용한 뇌파 분석에 대한 기초 연구)

  • Park, Hae Jeong;Park, Kwang Suk;Kwon, Jun Soo
    • Korean Journal of Biological Psychiatry
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    • v.2 no.2
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    • pp.257-265
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    • 1995
  • The object of this study is to apply a chaotic signal analysis method to the EEG research, especially in the aspect of neuropsychiatry, and to get some inspection of the chaotic phenomena according to the brain sites and subjects. We have acquired 21 channel EEG data and one EOG according to the international 10-20 system and calculated the correlation dimension. The subject groups are schizophrenics, bipolar disorder, major depression and normal control. They were all awoke and eye-closed. We have found no distinctive features from our experiments except temporal regions have slightly higher correlation dimension. There is also no specific distinctions between groups. We conjecture that these results are mainly because the subjects were not well controlled. EEG dimension may change in accordance with to the age, sex, medication and the time data were selected to calculate. We have also considered some conditions for a better and more objective research of chaotic analysis to EEG research. Better conditioning and standardizing the calculation of correlation dimension is necessary for the application of the chaotic analysis to neuropsychiatry.

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A Study of voluntary deliberation agency for resolving problems in film censorship (영화 심의 문제 해결을 위한 민간 자율 심의 기구의 필요성 모색)

  • Suh, Dae-Jeong
    • Journal of Digital Convergence
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    • v.12 no.12
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    • pp.537-544
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    • 2014
  • The film has far-reaching power than any other media. For this reason, a censorship has existed in some way but censorship is like a double-edged sword. If KMRB stood in front of a desire to preserve the morals of society and youth protection, creativity of artists must be shaken. On the contrary if free will is emphasized, social chaos will be increase. Thus most countries made various censorship systems in order to overcome this contradiction. In recent years, mainly on the issue of censorship and the rating is a tendency to transfer to the voluntary deliberation agency. However, this issue is still dealing with this problem at KMRB in Korea. Then KMRB mistakes itself as the guardian of situation ethics and morality. Recently various problems appeared in the film rating system. KMRB should be devolved on the voluntary deliberation agency in order to solve the problem. therefore this study The study will be to review the need for voluntary veliberation agency.

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

  • 강근;안광민;이형
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2002.11a
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    • pp.461-467
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    • 2002
  • Signals reduced from the brain had been considered as a noise that is caused by the stochastic process until 1980. The recent non-linear dynamic theory researches, however, reported that these signals are meaningful and deterministic chaos signals in which they show how the brain deals with various information Since this report, a wide range of researches has been carried out and still in progress. Thus, by using the correlational dimension, one of the non-linear analytical methods, the characteristics of the brain signals can be analyzed. In this thesis, the scent of lavender, which stimulates the olfactory sense, is introduced to measure EEG with the International 10-20 electrode system on 16 channels, and to analyze the interrelationship between the original signals before the stimulation and the changed signals after the stimulation. Finally, the effect of the scent stimulation to the brain is analyzed. The purpose of this thesis is to apply these analyzed results to the computerized mapping of the brain signals and possible ways of specifying the source of the brain signals through various medical applications.

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