• 제목/요약/키워드: f-stable

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Discrete-Time Sliding Mode Control with SIIM Fuzzy Adaptive Switching Gain

  • Chai, Chang-Hyun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제12권1호
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    • pp.47-52
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    • 2012
  • This paper focuses on discrete-time sliding mode control with SIIM fuzzy adaptive switching gain. The adaptive switching gain is calculated using the simplified indirect inference fuzzy logic. Two fuzzy inputs are the normal distance from the present state trajectory to the switching function and the distance from the present state trajectory to the equilibrium state. The fuzzy output $f_{out}$(k) out f k is used to adjust the speed the adaptation law depending on the location of the state trajectory. The simulation results showed that the proposed method had no chattering in case of uncertain parameter without disturbance. Moreover the convergent rate of the switching gain was faster and more stable even in case of disturbance.

7자유도 매니퓰래이터 협업로봇 설계 (Design of 7 D.O.F Manipulator Cooperation Robot)

  • 문용선;배영철;노상현;조광훈;박용구
    • 한국전자통신학회논문지
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    • 제5권1호
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    • pp.37-43
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    • 2010
  • 본 논문에서는 7자유도 매니퓰레이터를 개발에 있어서 각 관절에 2개 이상의 일반적인 모터를 적용하여 중공형 관절을 구현하고, 전장부가 내장된 소형 구조를 설계하였다. 또한 기존의 산업용 로봇의 한계로 지적받고 있는 작업 반경의 한계 및 위험성을 극복할 수 있는 방안을 제시하고 보다 효율적이며, 안전한 매니퓰레이터의 구현 방법을 제시한다.

동시경화용 복합재료의 특성에 따른 금형의 선택방법 (Selection Methodology of Tool for Co-cured Composite Materials)

  • 홍중표;이종옥;이원곤;홍정수;지우석;조한준
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2002년도 추계학술발표대회 논문집
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    • pp.183-188
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    • 2002
  • Co-cured composite materials has its own characteristics, so its thermal expansion is different each other. The selection of tool material for co-cured composite part in high temperature more over $350^{circ}F$ and 50 Psi pressure have to consider part thermal expansion, size, shape, and economic aspect in production line. So it is important choose tooling material in manufacturing composite parts. We called the tool for airplane composite parts as BAJ (Bonding Assembly Jig). Composite parts are cured on the BAJ in autoclave. BAJ have to stable at high temperature over $350^{circ}F$ and 50 Psi pressure, Considering composite parts' dimensional tolerance compare to heat up in autoclave. This paper come from the results of the experiment at the composite parts production line and review other aircraft company's method for tooling This is for the engineer engaged in composite parts manufacturing.

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THE SPACE-TIME FRACTIONAL DIFFUSION EQUATION WITH CAPUTO DERIVATIVES

  • HUANG F.;LIU F.
    • Journal of applied mathematics & informatics
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    • 제19권1_2호
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    • pp.179-190
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    • 2005
  • We deal with the Cauchy problem for the space-time fractional diffusion equation, which is obtained from standard diffusion equation by replacing the second-order space derivative with a Caputo (or Riemann-Liouville) derivative of order ${\beta}{\in}$ (0, 2] and the first-order time derivative with Caputo derivative of order ${\beta}{\in}$ (0, 1]. The fundamental solution (Green function) for the Cauchy problem is investigated with respect to its scaling and similarity properties, starting from its Fourier-Laplace representation. We derive explicit expression of the Green function. The Green function also can be interpreted as a spatial probability density function evolving in time. We further explain the similarity property by discussing the scale-invariance of the space-time fractional diffusion equation.

Treatment of Saline Wastewater by the Activated Sludge with Nonwoven Fabric Separation

  • Moon, Byung-Hyun;Heo, Jong-Soo;Choi, Hyoung-Sub
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제2권2호
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    • pp.136-140
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    • 1997
  • Direct membrane separation using nonwoven fabric was applied to saline wastewater treatment by an activated sludge process. A nonwoven fabric module was immersed in an aeration tank. The part of treated was filtered through the module by suction and the rest of that was separated by a settling tank. Various F/M ratios and salt concentrations were applied to investigate stable flux as well as pollutant removal. The pollutant removal efficiencies of nonwoven fabric separation was not affected by F/M ratios and salt concentrations and was higher than that of settling tank separation. The decline in flux was seemed to be caused by the biofilm on nonwoven fabric surface.

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항공기 제어면/구동장치 고장에 대한 진단규명 및 보완 제어시스템 설계에 관한 연구 (A study on the control surface/actuator fault detection, identification, and accommodation system for aircraft)

  • 송용규
    • 한국항공우주학회지
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    • 제30권7호
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    • pp.61-67
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    • 2002
  • 본 논문에서는 항공기의 제어면 혹은 구동장치가 고장이 났을 때 이를 신속하게 진단규명하고 안정한 상태로 되돌리기 위한 고장보완제어시스템을 설계한다. 제어시스템 설계에는 수렴 속도가 빠른 확장 역전파 알고리즘을 적용한 신경회로망을 이용한다. 제어대상으로는 비선형 운동방정식으로 표현된 F-4 항공기이며 수평미익이나 에일러런의 고장이 발생할 경우에 대하여 제어시스템을 설계하고 시뮬레이션을 통하여 성능을 검증한다.

Metabolic Stability of [18F]Fluoroalkylbiphenyls

  • Lee, Kyo-Chul;Lee, Sang-Yoon;Choe, Yearn-Seong;Chi, Dae-Yoon
    • Bulletin of the Korean Chemical Society
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    • 제25권8호
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    • pp.1225-1230
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    • 2004
  • The stability of fluoroalkyl groups as a pendent on the phenyl ring was measured in vitro using rat hepatic microsomes and human serum to predict their in vivo stabilities. We have prepared three [$^{18}F$]fluoroalkyl-biphenyls as the model compounds of fluoroalkyl aromatic compounds to compare the in vitro stabilities. In addition, in vitro stabilities were measured separately using rat hepatic microsomes and human serum at $37^{\circ}C$. Fluoroethylbiphenyl had similar or slightly superior stability to fluoropropylbiphenyl and these two compounds were much more stable than fluoromethylbiphenyl in vitro.

난과식물의 형질전환 유도 및 다량증식에 관한 연구. III. Electroporation에 의해서 자란의 원형질체로 도입된 유전자의 발현 (Studies on the Induction of Transformation and Multiplication in Orchid Plants.(III) Expression of Gene Transferred into Orchid Protoplasts by Electroporation)

  • 이정석;황성진김영준황백
    • KSBB Journal
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    • 제6권4호
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    • pp.385-388
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    • 1991
  • 자란(B. striata)의 미성숙종자로 부터 유도한 embryogenic callus를 현탁배양하고 이와같은 embryogenic cell suspensions로부터 분리한 원형질체에 electroporation 방법을 사용하여 reporter genes이 들어있는 pBI121 plasmid DNA 를 도입하고 그 발현을 확인하였다. 배양된 세포에 있어서 GUS의 활성은 plasmid DNA양의 증가와 함께 높게 나타났으며, 200-300 voltage/1180 uF에서 GUS의 활성 및 원형질체의 생존율(viability)이 가장 좋았다.

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피드백 요소를 고려한 전류모드 제어기의 안정도해석 (The stability analysis of current mode controller considering feedback element)

  • 김철진;송요창;진용선
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.239-241
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    • 2001
  • Recently the power supply equipments have tendency to take multiple feedback loop paths. In this paper, the state space averaging technique is applied for the analysis of flyback type current mode control circuit. We made real converter for the gurantee of stable output characteristic and proper design of feedback circuit. The validity of proposed method is verified from test results. The improvement of stability is confirmed by sinusoidal signal injection method with isolated transformer. It is known that phase margin is sufficient and gain crossover frequency $f_c$, is nearly 1/5 of switching frequency $f_s$, from the experimental result with frequency response analyzer.

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전류제어형 DC-DC컨버터의 안정도 향상에 관한 연구 (A Study on the stability improvement of current-mode controlled DC-DC Converter)

  • 김철진;송요창
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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    • pp.365-367
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    • 2000
  • Recently, the power supply equipments have tendency to take multiple feedback loop paths. In this paper, the state space averaging technique is applied for the analysis of flyback type current mode control circuit. We made real converter for the gurantee of stable output characteristic and proper design of feedback circuit. The validity of proposed method is verified from test results. The improvement of stability is confirmed by sinusoidal signal injection method with isolated transformer. It is known that phase margin is sufficient and gain crossover frequency $f_c$ is nearly 1/5 of switching frequency $f_s$ from the experimental result with frequency response analyzer.

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