• Title/Summary/Keyword: chaos

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Chaotic Double Tent Mapping PWM Scheme for Acoustic Noise Reduction of o Motor Drive) (전동기의 소음 저감을 위한 카오스 2중 텐트 사상 PWM기법)

  • Kim, Jun-Hyeoung;Jung, Young-Gook;Lim, Young-Cheol
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.12
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    • pp.71-78
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    • 2008
  • The paper proposes a chaotic double tent mapping PWM scheme for mitigation the acoustic noise of a motor chive. The chaos area ${\lambda}=0.99$ in bifurcation tree of the double tent mapping is used for generating the chaotic numbers. A 80C196 micro-controller is employed for generation of chaotic numbers, and the triangular carrier with chaotic frequency is obtained by using a 80C196 micro-controller and a MAX038 frequency modulator. The experiments are executed with a 1.5[kw] induction motor chive under the 2.5[A] load condition. As results, the experimental results show that the carrier, voltage and 3-D switching noise spectra of the proposed scheme is spread over the chaotic frequency range with no specific frequency concentration. Thereby, the shrill acoustic noise radiated from a motor chive is reduced by the proposed scheme.

Study of Radiation Mapping System for Water Contamination in Water System (방사능 수치 오염 지도 작성을 위한 방사선 계측 시스템 연구)

  • Na, Teresa W.;Kim, Han Soo;Yeon, Jei Won;Lee, Rena;Ha, Jang Ho
    • Journal of Radiation Industry
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    • v.5 no.2
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    • pp.185-189
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    • 2011
  • As nuclear industry has been developed, a various types of radiological contamination has occurred. After 9.11 terror in U.S.A., it has been concerned that terrorists' active area has been enlarged to use nuclear or radioactive substance. Recently, the most powerful earth-quake stroke, which triggered a massive tsunami in Japan and then Fukushima nuclear power plant reactor has suffered from a serious accident in history. The Fukushima reactor accident has occurred an anxiety of radiation leaks and about 170,000 people have been evacuated from the accidental area near the nuclear power plant. For these reasons, a social chaos can be occurred if radiological contamination occurs to the supply system for the drinking water. As such, the establishment of the radiation monitoring system for the city main water system is compelling for the national security. In this study, a feasibility test of radiation monitoring system which consists of unified hybrid-type radiation detectors was experimented for multi detection system by using gamma-ray imaging. The hybrid-type radiation sensors were fabricated with CsI(Tl) scintillators and photodiodes. A preamplifier and amplifier was also fabricated and assembled with the sensor in the shielding case. For the preliminary test of detection of radiological contamination in the river, multi CsI(Tl)-PIN photodiode radiation detectors and $^{137}Cs$ gamma-ray source were used. The DAQ was done by Linux based ROOT program and NI DAQ system with Labview program. The simulated contamination was assumed to be occurred at Gapcheon river in Daejeon city. Multi CsI(Tl)-PIN photodiode radiation detectors were positioned at the Gapcheon river side. Assuming that the radiological contaminations flows in the river the $^{137}Cs$ gamma-ray source has been moved and then, the contamination region was reconstructed.

Yaeun(壄隱) Jeon Nok Saeng(田祿生)'s Idea of Justice and Theory of Governing (야은(壄隱) 전록생(田綠生)의 의리사상(義理思想)과 경세론(經世論))

  • Jeong, Seong Sik
    • (The)Study of the Eastern Classic
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    • no.35
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    • pp.135-159
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    • 2009
  • Since the military servants' rebellion, the society of the Goryeo(高麗) dynasty had been getting into crisis worse and worse until late in it. Late in the 14th century, the society was constantly meeting tension and chaos including decline of the Yuan(元) dynasty, sudden rise of the Ming(明) dynasty and etc. This study is aimed to investigate the idea of justice and theory of governing advocated by Yaeun Jeon Nok Saeng, who lived in such tensed and chaotic era. Under the circumstance that threatened the national power of the Goryeo dynasty in the era where the Yuan dynasty changed to Ming dynasty, his idea of justice was expressed as "Theory for Friendship with Ming and Against Yuan", which was proposed in the aspect of considering the safety and maintenance of the nation and getting back the original national power of a country Goryeo. He thought that you should not make your people bothered by or troubled in their works but you should make them concentrate on their jobs for living to govern them eased. He emphasized that you should focus on stability of people's welfare in gentle ways not bothering your people even a little bit because he thought that the situation of that era looked like a thread bobbin so that it could get naturally and easily twisted if you went in hurry.

A study of fashion illustration applying grotesque characteristics (그로테스크의 특징을 활용한 패션 일러스트레이션 연구)

  • Heo, Seungyeun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.21 no.1
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    • pp.35-45
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    • 2019
  • This study was initiated to add value to fashion illustration as a genre of plastic art, as its importance as a progressive visual art is growing. The research purpose is to analyze characteristics of Grotesque, a subculture that emerged from the challenges and problems of groups which deviated from social and cultural trends, and to develop fashion design illustration utilizing the characteristics unique to that subculture. As a method of research, this study examined the characteristics and expression methods of Grotesque, which appeared in fashion literature, referenced a prior study of Grotesque, and developed fashion design illustration using Grotesque as a based. The result of this study are as follows. First, the characteristics of Grotesque that are applicable to fashion illustration were derived as 'evil, aversion, playfulness, heterogeneity, and abnormality'. Second, the expressive elements of Grotesques, reflecting the beauty of ugliness, present a methodology for developing new and creative fashion design illustrations. Third, it was found that Grotesque fashion illustration is a visual tool that is suitable for expressing the problematic origins of human existence, values, alienation, and social chaos. Fourth, 'arthropod' motifs were identified as a suitable theme for extracting the newly integrated Grotesque images through the process of contradiction and confrontation between humans and objects. Fifth, the Grotesque fashion illustrations could be understood in terms of plastic arts, and could provide a gateway to rediscovering human dignity. Based on the finding, we expect that creative design thinking and development that combines the motifs of various themes and Grotesque's expressive methods will proceed more deeply and specifically.

Microcontroller based Chaotic Lorenz System for Secure Communication Applications (암호통신 응용을 위한 마이크로 컨트롤러 기반 로렌츠 카오스 시스템)

  • Jayawickrama, Chamindra;Song, Hanjung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.12
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    • pp.1698-1704
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    • 2018
  • This paper presents a implementation of a chaotic Lorenz system for data secure communication applications. Here we have used PIC18F family-based microcontroller to generate the chaotic signal, and simulated waveform patterns confirm that the chaotic behavior of the microcontroller based discrete time chaotic Lorenz system. There are three R-2R ladder type A/D converters have been implemented for conversion of direct microcontroller digital output into analog waveform, utilizing this specific microcontroller relevant to this experiment work, microcontroller ports B, C and D have been utilized for its time waveform outputs X, Y and Z respectively. XC8 compiler used for the compilation of the program. MATLAB and PROTEUS software platforms are used for simulation. Finally, chaotic time wave forms, 2D chaotic attractors were obtained and secure communication analog waveforms were also verified by experimental measurement.

Revising the Archives Law to Boost Commercial Records Facilities Industry : Issues & Tasks (민간시설 활성화를 위한 공공기록법 개정(안) : 쟁점과 과제)

  • Lee, So-Yeon
    • The Korean Journal of Archival Studies
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    • no.47
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    • pp.197-225
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    • 2016
  • Korean archival community had continuously dealt with attempts at weakening the core of records and archives principles in the name of deregulation. In 2015, Korean government announced revisions of the Archives Law in order to boost uses of commercial records facilities by public institutions. As key concepts were unclear and understandings among stake-holders varied, a considerable degree of chaos and anxiety aroused. The amendment itself was held at National Assembly. The unresolved disputes rested, however, waiting for another attempt of similar nature. As the recognition propelled this paper, it aimed at reviewing major contending arguments and proposing future actions.

Modern Dualism and Le Corbusier's Ideas (근대의 이원론과 르 코르뷔지에의 사고)

  • Lee, Jae-Young
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.11
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    • pp.101-108
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    • 2019
  • In this study, Le Corbusier's ideas were investigated from the view point of modern dualism. Le Corbusier, pioneer of modern architecture, insisted a rationalistic architecture for the industrial period, considering a house as 'machine for living'. In the other way, he tried to arouse emotions through architecture, mentioning a house as 'machine for affecting'. In his writings and paintings, he divided the world in the two opposed things (ex: human and nature, reason and sensation, chaos and order, orthogonal and libre curve, man and woman, sun and moon, lightness and darkness, bull and woman, and etc), and tried to combined the these two divided things. In architecture, he amalgamated his white buildings with the green vegetation, which is styled in the harmony of contrast(nature and articial). In urbanism, Le Corbusier did not divide nature only into three material elements for living(sunlight, air, green space), but also pursued poetic and aesthetic nature through buildings under the rays of sun and among the vegetation. Le Corbusier's dualistic ideas are based on Descartes's modern dualism, which divided the world into the material and the spiritual and into the objective and the subjective. Due to this original division, modern dualism contains the limits of extreme subjectification on human signification and of separation from the world and nature. Le Corbusier pursued the combination of the two divided things to overcome the contradiction of dualism, but his ideas and works contain the limits of the modern dualism.

A Study on the Secure Plan of Security in SCADA Systems (SCADA 시스템의 안전성 확보방안에 관한 연구)

  • Kim, Young-Jin;Lee, Jung-Hyun;Lim, Jong-In
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.6
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    • pp.145-152
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    • 2009
  • SCADA(Supervisory Control And Data Acquisition) systems are widely used for control and monitoring of critical infrastructures including electricity, gas and transportation. Any compromise in the security of SCADA systems could result in massive chaos and disaster at a national level if a malicious attacker takes the control of the system. Therefore, sound countermeasures must be provided when the SCADA systems are being developed as well as when they are being operated. Unlike general information processing system, SCADA systems have different service responses, communication protocols and network architectures and therefore a different approach should be applied to each SCADA systems that takes into consideration of each system's security characteristics and architectures. In addition, legal basis should be established to ensure the nationwide management of the systems security. This paper examines the vulnerabilites of SCADA systems and proposes action plans to protect the systems against cyber attacks.

Discussion on the Concept of Terminology in the Introduction of Virtual Studio (가상스튜디오 도입기의 용어 개념에 관한 논의)

  • Nah, So-Mi
    • Journal of Convergence for Information Technology
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    • v.12 no.1
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    • pp.91-98
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    • 2022
  • Currently, new terms are overflowing with the development of technology from VR, AR, XR to Metaverse. Every time a term is generated in this way, society considers it a new technology and tends to use it enthusiastically, but there is confusion in correctly understanding and utilizing the category of the term. He would like to discuss the virtual studio that played an important role in the development of broadcasting CG (Computer Graphics) technology in the 1990s, and talk about the introduction of new terms in the past and how to use them. Therefore, this paper examines the gap between chaos and upright each time a term is generated based on the time when the virtual studio is introduced, and analyzes the utilization of new technology from the past through the introduction machine manufacturing case. By examining the past technological development processes expressed by remediation, this paper argues that the current situation is not a new technology but an expression of a new term, that is, a phenomenon that appears during the gradual development of technology. It is something to do.

Nurses' Experiences of the COVID-19 Crisis (COVID-19 위기상황에 대한 간호사의 경험)

  • Lee, Jung-Hoon;Song, Yeoungsuk
    • Journal of Korean Academy of Nursing
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    • v.51 no.6
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    • pp.689-702
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    • 2021
  • Purpose: This study aimed to develop a situation-specific theory to explain nurses' experiences of the COVID-19 crisis. Methods: The participants were 16 hospital nurses who experienced the COVID-19 crisis. Data were collected through in-depth individual interviews from September 2, 2020 to January 20, 2021. Transcribed interview contents were analyzed using Corbin and Strauss's grounded theory method. Results: A total of 38 concepts and 13 categories were identified through an open coding process. The core category found was becoming a pioneering nurse who turns crises into opportunities. The causal conditions were the chaos of being exposed defenselessly to an unexpected pandemic, fear caused by a nursing care field reminiscent of a battlefield, and moral distress from failing to protect patients' human dignity. The contextual conditions were feeling like the scapegoat of the hospital organization, increasing uncertainty due to the unpredictable state of COVID-19, and relative deprivation due to inappropriate treatment. The central phenomenon was suffering alone while experiencing the dedication of the COVID-19 hero image. The action/interactional strategy were efforts to find a breakthrough and getting the nurse's mind right, and the intervening conditions were gratitude for those who care for broken hearts and getting used to myself with repetitive work. The Consequences were becoming an independent nurse and frustration with the unchanging reality. Conclusion: This study provides the foundation for the nurse's situation-specific theory of the COVID-19 crisis by defining the crisis perceived by nurses who cared for COVID-19 patients and suggesting types of coping with the crisis.