• 제목/요약/키워드: Large system

검색결과 16,663건 처리시간 0.043초

고분자젤 내에서 분자체 거동현상 연구 (Study of Transport Phenomena of Large Ionic - Molecules Inside Polymeric Gel)

  • 박영규;성기천
    • 한국응용과학기술학회지
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    • 제18권1호
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    • pp.1-6
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    • 2001
  • Theoretical model has been studied for the transport phenomena of molecules in the system where an electric potential is applied to the system in the axial direction. The effect of electrophoretic convection in the polymeric media is significantly contributed to separate large ionic-molecules because the conformation of large ionic-molecule quickly orients in the field direction. The dependence of the transport in the polymeric media upon field intensity and molecular size aids in understanding the transport of large ionic-molecule in the system, since the convective velocity of large ionic-molecule is accelerated inside a porous material. The transport distance of individual large ionic-molecule can be predicted using the reptation theories.

반사경 측정을 위한 타워 방식의 Fold Mirror를 이용한 Fizeau 간섭계 시스템 구성 (A Study on the Tower type Fizeau Interferometer System with a Fold Minor for Measuring Large Optical Lens Profile)

  • 이응석;이기암;김옥현
    • 한국정밀공학회지
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    • 제25권8호
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    • pp.21-28
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    • 2008
  • Fizeau interferometer is used for inspecting the lens surface profile accurately. This study is focused on the design and optical measuring techniques for large optical components, such as a reflection mirror for large area lithography or astronomical purpose. A tower type Fizeau interferometer is designed and set up in horizontally with a 45$^{\circ}$ fold mirror which makes easy to align the optical path of heavy interferometer system. To align the optical path, a five-axes stage for the interferometer is required. This study shows a method of the 45$^{\circ}$ fold mirror alignment by using a three-axis stage instead of adjusting the interferometer itself or measuring object. This system will be installed on the large optics polishing machine during the manufacturing process as an on-machine inspection system.

고유구조지정법을 이용한 유연구조물의 스필오버 억제방법 (A Spillover Suppression Method in a Flexible Structure Using Eigenstructure Assignment)

  • 최재원;박운식
    • 제어로봇시스템학회논문지
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    • 제6권11호
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    • pp.955-962
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    • 2000
  • Although large space structures(LSS) such as a space station, a solar power station satellite, etc., are theoretically distributed parameter and infinite-dimensional systems, they have to be modeled into a lumped parameter and large finite-dimensional system for control system design. Besides, there remains the fundamental problem that the modeled large finite-dimensional system must be controled with a much smaller dimensional controller due to the limitation of computing resources. This causes the spillover phenomenon which degrades control performances and reduces the stability margin. Furthermore, it may destabilize the entire feedback control system. In this paper, we propose a novel spillover suppression method in the active vibration control of large flexible structures by using eigenstructure assignment. Its validity and effectiveness are investigated and verified by the numerical experiments using a simply supported flexible beam, which is modeled to have four controlled modes and eight uncontrolled modes.

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대형 수이젝터를 이용한 다목적댐 관개용수 펌핑시스템에 관한 연구 (A study on the irrigation water pumping system of multipurpose dams by the large water ejector)

  • 윤석훈;오철;손근홍;김철환
    • Journal of Advanced Marine Engineering and Technology
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    • 제18권1호
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    • pp.73-80
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    • 1994
  • The water ejector is a low pressure high flow rate volumetric pump. It utilize the energy of a low mass flow, high velocity stream to induce a large mass flow, low velocity stream. In addition, it has a very good resistances to cavitation compared to the other type of pumps, and the maintenance cost is practically nil. There has been enormous energy loss to supply the upper part water of dam which has large potential energy as mere irrigation water in domestic multipurpose dam. The new type of energy saving system which developed through the present study can economizes over 950,000 kWh per year by mixing the upper part water of dam with the waste water by the large water ejector. This paper estimates the economical efficiency of the new type of irrigation water pumping system, and further more, represents the change of performance characteristics of large water ejector, which was adapted to this system, according to the fluctuation of upper water level that seasonally changes.

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다항식 퍼지 대규모 시스템의 출력 궤환 제어기 설계 : 제곱합 접근 방법 (Design of Output Feedback Controller for Polynomial Fuzzy Large-Scale System : Sum-of-Square Approach)

  • 김한솔;주영훈;박진배
    • 한국지능시스템학회논문지
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    • 제21권5호
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    • pp.549-554
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    • 2011
  • 본 논문에서는 출력 궤환 제어기를 이용해 다항식 퍼지 대규모 시스템을 안정화하는 방법을 제안한다. 이를 위해, 먼저, 대규모 시스템의 부분 시스템에 대해 퍼지 모델링을 한 후, 각각에 대해 출력 궤환 제어기를 설계하여 대규모 시스템을 안정화하는 방법을 제안한다. 이때, 다항식 Lyapunov 함수를 적용하면 다항식 퍼지 대규모 시스템의 안정화 조건은 제곱합 조건으로 주어지고, 이것은 MATLAB의 툴박스인 SOSTOOLS로 해석 가능하다. 이러한 과정을 거친 후에 얻어진 해에서 시스템을 안정화시키는 출력 궤환 제어기의 이득을 구할 수 있다. 마지막으로, 제안된 기법의 적합성을 검증하기 위해 시뮬레이션 예제가 주어진다.

A PROPOSAL OF ENHANSED NEURAL NETWORK CONTROLLERS FOR MULTIPLE CONTROL SYSTEMS

  • Nakagawa, Tomoyuki;Inaba, Masaaki;Sugawara, Ken;Yoshihara, Ikuo;Abe, Kenichi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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    • pp.201-204
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    • 1998
  • This paper presents a new construction method of candidate controllers using Multi-modal Neural Network(MNN). To improve a control performance of multiple controller, we construct, candidate controllers which consist of MNN. MNN can learn more complicated function than multilayer neural network. MNN consists of preprocessing module and neural network module. The preprocessing module transforms input signals into spectra which are used as input of the following neural network module. We apply the proposed method to multiple control system which controls the cart-pole balancing system and show the effectiveness of the proposed method.

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배전변전소에 대용량변압기로 교체 적용시 보호협조를 위한 초전도 전류제한기의 임피던스 분석 (Analysis on SFCL's Impedance for Protective Coordination in Large Transformer installed in Distribution Substation)

  • 김진석;김명후;류일경;문종필;임성훈;김재철;안재민
    • 전기학회논문지
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    • 제58권8호
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    • pp.1479-1484
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    • 2009
  • The introduction of the large transformer due to the large power demand has increased the fault current in power distribution system. The increased fault current can exceed the cut-off ratings of the circuit breaker. As the methods to solve this problem, the superconducting fault current limiter(SFCL) has been notified. However, the limited fault current by SFCL affects the operational characteristics of the protective device such as overcurrent relay. Therefore, the selection of the proper impedance for the SFCL is required to keep overcurrent relay's protective coordination with the SFCL when a large transformer is introduced into the distribution system. In this paper, the SFCL's impedance for protective coordination was investigates in that a large transformer is introduced.

A proposal of switching control system based on speculative control and its application to antiskid braking system

  • Masaaki Inaba;Ikuo Yoshinhara;Hai-jiao Guo;Kazuo Nakao;Kenichi Abe
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.585-588
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    • 1997
  • This paper presents a construction method of logic-based switching control system which operates in widely changing environments. The logic-based switching controller is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environments. Switching from one candidate controller to another is carried out based on monitoring the output of the system. The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environment in advance; (2)the supervisor applies a sequence of speculative controls to a plant with candidate controllers just after the control has started and just after the change of the environment has been detected. It is important that each candidate controller can keep the system stable during a sequence of speculative controls, and the most appropriate candidate controller for the environment to which the system is exposed can be selected before the last speculative control is ended. An application to an antiskid braking system clarifies the effectiveness of the proposed method.

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부유식 초대형 해상구조물의 건설을 위한 법제도 개선에 관한 연구 (A Study on Improvement of Legal System for Construction of Very Large Floating Structure)

  • 이한석;송화철
    • 한국항만학회지
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    • 제13권2호
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    • pp.365-380
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    • 1999
  • In this thesis the legal systems related to real estate and sea area utilization are studied in order to improve them for construction of Very Large Floating Structure. Main research subjects are as follows: 1) Whether can Very Large Floating Structure be accepted or not as real estate like house and land\ulcorner 2) How can the sea area which is occupied by Very Large Floating Structure be utilized\ulcorner As the conclusion, the Very Large Floating Structure can be registered as real estate even though it is not specified by Korean law for the present. The design concept of Very Large Floating Structure can be interpreted as satisfying enough necessary conditions and factors for Very Large Floating Structure to become real estate. In the near future, we have to make improvement on the laws related with the construction of Very Large Floating Structures so that private sectors can joint the construction. In additions, a new law for various floating structures should be made as soon as possible.

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기술시스템 (Large Technological Systems) 이론구조를 활용한 경마방송 비교연구 (The Comparative Analysis of Gambling Media System in the Construction of a Large Technological System)

  • 정구현;서명천;조규동
    • 방송공학회논문지
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    • 제20권2호
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    • pp.273-282
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    • 2015
  • 본 연구는 경마산업에서 중요한 요소 중의 하나인 경마방송을 살펴보고자 한다. 한국의 경마방송과 해외선진국과 비교했을 때 어떤 차이점이 있는지를 Hughes(1987)의 기술시스템(Large Technological Systems) 관점에서 분석함으로써 향후 경마산업의 한 전문분야에 비전을 제시할 수 있는 것을 목적으로 한다. 본 연구는 크게 두 가지 관점에서 접근하는데, 우선 한국의 경마방송을 기술시스템 구조를 적용하여 연구 대상들을 개념화하고 두 번째로는 개념화를 기준으로 해외 비교대상들과 공통점과 차이점을 파악하고자 한다. 비교를 통해 한국 사례에서 방해가 되는 역돌출 요소는 무엇인지 분석하고 도출된 결과를 바탕으로 시행체 직접 운영에 의한 빠른 정책결정, 경쟁력 있는 콘텐츠 개발, 해외 개방정책 및 방송통신 융합흐름에 따른 미래 정책 개발 등 경마방송을 활용한 경마산업의 균형적인 발전을 위한 비전과 시사점을 제시하였다.