• Title/Summary/Keyword: closed ideal

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A New Integral Variable Structure Regulation Controller for Robot Manipulators with Accurately Predetermined Output Performance (로봇 매니플레이터를 위한 정확한 사전 결정 출력 성능을 갖는 새로운 적분 가변구조 레귤레이션 제어기)

  • Lee, Jung-Hoon
    • Journal of IKEEE
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    • v.8 no.1 s.14
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    • pp.96-107
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    • 2004
  • In this paper, a new integral variable structure regulation controller(IVSRC) is designed by using a special integral sliding surface and a disturbance observer for the improved regulation control of highly nonlinear robot manipulators with prescribed output performance. The sliding surface having the integral state with a special initial condition is employed in this paper to exactly predetermine the ideal sliding trajectory from a given initial condition to origin without any reaching phase. And a continuous sliding mode input using the disturbance observer is also introduced in oder to effectively follow the predetermined sliding trajectory within the prescribed accuracy without large computation burden. The performance of the prescribed tracking accuracy to the predetermined sliding trajectory is clearly investigated in detail through the two theorems together with the closed loop stability. The design of the proposed IVSRC is separated into the performance design and robustness design in each independent link. The usefulness of the algorithm has been demonstrated through simulation studies on the regulation control of a two link manipulator under parameter uncertainties and payload variations, in view of no reaching phase, no overshoot, predetermined response with prescribed accuracy, easy change of output performance, separation of design phase, and so on.

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Effect of LED Light Quality Treatment on the Functional Optimization of Foliage Plant (LED 광질이 관엽식물의 기능성 최적화에 미치는 영향)

  • Kim, Myung-Seon;Chae, Soo-Cheon;Ann, Seoung-Won;Choi, Won-Chun;Lee, Myung-Won;Lee, Kook-Han;Liu, Xiao-Ming
    • Journal of Environmental Science International
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    • v.21 no.5
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    • pp.633-640
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    • 2012
  • White light and compound light were found to be the ideal light sources for improving the functionality and ornamental value of indoor plants and reducing the cost of maintenance, but because compound light hinders people from recognizing the original color of plants and makes their eyes easily tired, white light was considered the optimal light satisfying all of the ornamental value, economic efficiency and functionality resulting from plant growth. On the other hand, in the results of examining physiological changes before and after treatment on fine dust PM10 and carbon dioxide removal capacity in a closed chamber under an artificial light source, the patterns of carbon dioxide and fine dust removal were similar among the treatment groups according to light condition, but according to plant type, the removal rate per unit leaf area was highest in $Spathiphyllum$ and lowest in $Dieffenbachia$. In the experiment on dust and carbon dioxide removal, the photosynthetic rate was over 2 times higher after the treatment, and the rate increased particularly markedly under compound light and white light, suggesting that the photosynthetic rate of plants increases differently according to light quality. These results show that light quality has a significant effect on the photosynthetic rate of plants, and suggests that plants with a high photosynthetic rate also have a high carbon dioxide and dust removal capacity. In conclusion, the photosynthetic rate of foliage plants increased under white and blue light that affect photosynthesis and the increased photosynthetic rate reduced carbon dioxide and fine dust, and therefore white and compound light were found to be the optimal light sources most functional and economically efficient in improving ornamental value and indoor air quality.

Effect of Gypsum Application on Reducing Methane (CH4) Emission in a Reclaimed Coastal Paddy Soil (간척지 논 토양 개량제로서 석고처리가 메탄 배출량 저감에 미치는 영향)

  • Lim, Chang-Hyun;Kim, Sang-Yoon;Kim, Pil-Joo
    • Korean Journal of Environmental Agriculture
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    • v.30 no.3
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    • pp.243-251
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    • 2011
  • BACKGROUND: Gypsum($CaSO_4{\cdot}2H_2O$) is known as an ideal amendment to improve soil quality of the reclaimed coastal land. Since gypsum has very high concentration of electron acceptor like ${SO_4}^{2-}$, its application might be effective on reducing $CH_4$ emission during rice cultivation, but its effect has not been studied well. METHODS AND RESULTS: The effect of gypsum on $CH_4$ emission and rice growth characteristics was studied by pot test, which was packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Chemical-grade gypsum was applied in two soils having EC 2.25 and 9.48 dS/m at rates of 0, 0.5, 1.0 and 2.0%(wt/wt). $CH_4$ emission was characterized a week interval by closed chamber method during rice cultivation. $CH_4$ emission rate was significantly decreased with increasing salt accumulation and gypsum application levels. With increasing gypsum application, dissolved ${SO_4}^{2-}$ concentration in the leachate water was significantly increased, which might have suppressed $CH_4$ production in soil. Total $CH_4$ flux was dramatically decreased with increasing gypsum application. In contrast, rice yield was increased with increasing gypsum application and then achieved maximum productivity at 1.0% gypsum application in two soils. CONCLUSION(s): Gypsum is a very good soil amendment to suppress $CH_4$ emission in reclaimed coastal paddy soils, and improve rice productivity and soil properties. The optimum application level of gypsum is assumed at ca. 1% to improve soil productivity with reducing effectively $CH_4$ emission during rice cultivation.

The Living Theatre: A History Study of Its Birth and Death (리빙 씨어터: 탄생과 소멸에 관한 사적(史的) 연구)

  • Kim, Jung-hyo
    • Journal of Korean Theatre Studies Association
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    • no.40
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    • pp.207-237
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    • 2010
  • Concentrating on the birth, life, and death of the Living Theatre, almost half a century avant-garde group, the primary purpose of this study at large is to explore its counter-cultural philosophy. While taking a chronological form adapting the biological order, the paper focuses on the troupe's productions: , , , , and . Through out these productions the philosophy of the Living Theatre seemed to included communal, anti-intellectual, politically radical, generally Utopian, and proselytizers for sexual freedom. The history of the Living Theatre interestingly parallels the history of the Beck's theatre in occupation and shut down. The first New York theatre was closed by fire inspectors for instance. The second theatre was declared unsafe, and locked up by the Building Department. The third theatre was seized by the IRS, consequently shut down. In 1984, after more than 25years from the third building, the Living Theatre settled once again on East Third Street in Manhattan. The theatre was however evacuated by the New York City Fire Department in 1993 and once more took to the road. With these struggles, the Becks' profound aspiration of the counter-cultural insurgency came to harden as strong as 'iron' in some ways. With the outstanding components of counter-cultural philosophy and style, the Living Theatre, in the course of the transformation, absorbed and then reflected virtually every phase for the Living Theatre were vehicles for more than just aesthetics. The group seemed to propagandize its beliefs rather performing productions. Accordingly, both on and off-stage action of the Living Theatre caused great controversy either through political activism of individual members or through the unconventional collective life style. No avant-garde theatre company was more emblematic of the rebellious spirit of the sixties than the Living Theatre. Like the first great transformation, the Becks' encounter, their personal values and the form of theatre they created had blended 'so inextricably that the vitality of each was dependent on the other.' The Becks always urged unity and harmony at all levels of human life, but not at any price. The anticapitalist ideal inspired the Becks to promote a politically motivated campaign throughout their productions. They believed the revolution is desirable but in the state of non-violence and the expansion of human consciousness. Julian Beck's gravestone identifies his as pet, painter, actor, and anarchist. The Living Theatre was a 'small umbrella' under which the Becks and its members could breath and unfold their dream on stage or in the street.

A View about Li(理) and Ki(氣) of Hayasi Razan(林羅山) (하야시 라잔(林羅山)의 이기관(理氣觀))

  • Lee, Yongsoo
    • The Journal of Korean Philosophical History
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    • no.31
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    • pp.347-374
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    • 2011
  • Along with Hujiwara Seika(藤原惺窩), Hayashi Razan(林羅山) is called the founder of the Japanese Confucianism in the Eto(江戶) era. And it is necessary for us to grasp that how Razan understand the theory of I-Ki(理氣論), then we can investigate the characteristics of his thought. In ordinary, people understand that the theory of I-Ki, as a completed view of the world, is integration of the structure of theory of the neo-Confucianism. So a certain thinker's ideological attitude is determined according to how people understand the theory. And then we can grasp the structure of his view of the world and human. Therefore, the purpose of this paper is to study how Razan had understanded the I(理) and Ki(氣). In spite of a scholar of Zhu Xi(朱熹), Razan didn't accept Zhu's view of I-Ki, he seem to lean toward the view of Wang Yangmings'(王陽明) in the his early learning days. But that doesn't mean he is a scholar of doctrine of Wang Yangming. When he meets the logical contradiction under the process of investigating the problem of Sein and Sollen, he just only to explain it with logic of Ki(氣) which is closed by mind. Meanwhile if we suppose I(理) is pure goodness and there is no things outside of I(理), if so Razan doubts about that where is the root of evil and he try to investigate the answer. In his latter years, Razan takes Zhu Xi's doctrine again get out of the mental attitude to the view of I-Ki(理氣). The outcome of precedent study about Razan points a fact that Razan needs a little more digging into the ieda of 'Fact and Sollen' which had been the reason of ideal confusion of him. But his ideal confusion is not the point of issue. Point is that Razan had understanded I-Ki(理氣) with monistic of Shim(心) in his early years. As a result, that bring about the outcome which exclude ontological thinking, and had come to grips with aspects of Sollen of all things in understanding of the doctrine of Zhu Xi. And I think that is the clue to understanding of Razan's learning.

Application of CMP Process to Improving Thickness-Uniformity of Sputtering-deposited CdTe Thin Film for Improvement of Optical Properties (스퍼터링 증확 CdTe 박막의 두께 불균일 현상 개선을 위한 화학적기계적연마 공정 적용 및 광특성 향상)

  • Park, Ju-Sun;Lim, Chae-Hyun;Ryu, Seung-Han;Myung, Kuk-Do;Kim, Nam-Hoon;Lee, Woo-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.375-375
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    • 2010
  • CdTe as an absorber material is widely used in thin film solar cells with the heterostructure due to its almost ideal band gap energy of 1.45 eV, high photovoltaic conversion efficiency, low cost and stable performance. The deposition methods and preparation conditions for the fabrication of CdTe are very important for the achievement of high solar cell conversion efficiency. There are some rearranged reports about the deposition methods available for the preparation of CdTe thin films such as close spaced sublimation (CSS), physical vapor deposition (PVD), vacuum evaporation, vapor transport deposition (VTD), closed space vapor transport, electrodeposition, screen printing, spray pyrolysis, metalorganic chemical vapor deposition (MOCVD), and RF sputtering. The RF sputtering method for the preparation of CdTe thin films has important advantages in that the thin films can be prepared at low growth temperatures with large-area deposition suitable for mass-production. The authors reported that the optical and electrical properties of CdTe thin film were closely connected by the thickness-uniformity of the film in the previous study [1], which means that the better optical absorbance and the higher carrier concentration could be obtained in the better condition of thickness-uniformity for CdTe thin film. The thickness-uniformity could be controlled and improved by the some process parameters such as vacuum level and RF power in the sputtering process of CdTe thin films. However, there is a limitation to improve the thickness-uniformity only in the preparation process [1]. So it is necessary to introduce the external or additional method for improving the thickness-uniformity of CdTe thin film because the cell size of thin film solar cell will be enlarged. Therefore, the authors firstly applied the chemical mechanical polishing (CMP) process to improving the thickness-uniformity of CdTe thin films with a G&P POLI-450 CMP polisher [2]. CMP process is the most important process in semiconductor manufacturing processes in order to planarize the surface of the wafer even over 300 mm and to form the copper interconnects with damascene process. Some important CMP characteristics for CdTe were obtained including removal rate (RR), WIWNU%, RMS roughness, and peak-to-valley roughness [2]. With these important results, the CMP process for CdTe thin films was performed to improve the thickness-uniformity of the sputtering-deposited CdTe thin film which had the worst two thickness-uniformities of them. Some optical properties including optical transmittance and absorbance of the CdTe thin films were measured by using a UV-Visible spectrophotometer (Varian Techtron, Cary500scan) in the range of 400 - 800 nm. After CMP process, the thickness-uniformities became better than that of the best condition in the previous sputtering process of CdTe thin films. Consequently, the optical properties were directly affected by the thickness-uniformity of CdTe thin film. The absorbance of CdTe thin films was improved although the thickness of CdTe thin film was not changed.

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