• 제목/요약/키워드: Active State

검색결과 1,742건 처리시간 0.027초

탈질화 반응기의 설계 및 특성에 관한 연구 (A Study on the Design of Denitrification Reactor and the Characteristics)

  • 김선화;송주영
    • 생명과학회지
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    • 제11권3호
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    • pp.273-278
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    • 2001
  • Removal of nitrogen compound from waste water is essential and often accomplished by biological process. Deni-trification bacterium. Paracoccus denitrificans(KCTC 2350) is employed to estimate the ability and the characteristics of denitrification. In the immobilized biological reactor system, the measurement of absolute amount of active strain in the reactor is comparatively difficult or impossible. In this study, strain immobilized denitrification reactor was designed with the unwoven texture wrapped peeped hole plastic tube to calculated the absolute amount of active strain by comparing the activity of the immobilized reactor adn the free cell reactor. The reactor system was continuous stirred tank reactor and the rate of substrate consumption was assumed to be Michaelis-Menten equation. As a result, we found that the amount of immobilized active strain was the half of the total active strain in the reactor and the time required to reach in the equilibrium state in the immobilized reactor system was shorter than that of the free cell reactor system.

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Study of a SEPIC-input Self-driven Active Clamp ZVS Converter

  • Cao, Guo-En;Kim, Hee-Jun
    • Journal of international Conference on Electrical Machines and Systems
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    • 제2권2호
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    • pp.202-215
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    • 2013
  • This paper proposes a SEPIC-input, self-driven, active clamp ZVS converter, where an auxiliary winding and a RC delay circuit are employed to drive the active clamp switch and to achieve asymmetrical duty control without any other extra circuits. Based on the fixed dead time and the resonance between capacitors and inductors, both the main switch and the auxiliary switch can rule the ZVS operation. Detailed operation modes are presented to illustrate the self-driven and ZVS principles. Furthermore, an accurate state-space model and the transfer functions of the proposed converter have been presented and analyzed in order to optimize dynamic performance. The model provides efficient prediction of converter operations. Experimental results, based on a prototype with 80V input and 15V/20A output, are discussed to verify the transient and steady performance of the proposed converter.

Seismic Response Control of Bridge Structure using Fuzzy-based Semi-active Magneto-rheological Dampers

  • Park, Kwan-Soon;Ok, Seung-Yong;Seo, Chung-Won
    • International Journal of Safety
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    • 제10권1호
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    • pp.22-31
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    • 2011
  • Seismic response control method of the bridge structures with semi-active control device, i.e., magneto-rheological (MR) damper, is studied in this paper. Design of various kinds of clipped optimal controller and fuzzy controller are suggested as a semi-active control algorithm. For determining the control force of MR damper, clipped optimal control method adopts bi-state approach, but the fuzzy control method continuously quantifies input currents through fuzzy inference mechanism to finely modulate the damper force. To investigate the performances of the suggested control techniques, numerical simulations of a multi-span continuous bridge system subjected to various earthquakes are performed, and their performances are compared with each other. From the comparison of results, it is shown that the fuzzy control system can provide well-balanced control force between girder and pier in the view point of structural safety and stability and be quite effective in reducing both girder and pier displacements over the existing control method.

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분산전원용 인버터의 유효 무효전력 감결합을 통한 PQ제어 과도상태 특성개선 (Improved Transient Response of Distributed Energy Resources Inverters to PQ Control using Decoupling)

  • 최철훈;최종우;이창희
    • 전력전자학회논문지
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    • 제17권5호
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    • pp.438-444
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    • 2012
  • This paper deals with the active and reactive power control of Grid connected system. It was shown that active power and reactive power can be dependently controlled with two individually adaptable parameters. The two parameters are power angle and voltage magnitude. Transient state will occur with active or reactive power reference value variation. This paper presents a new control strategy for active and reactive power control of less interaction and improved transient response. The paper details the control technique by the mathematical and electrical network analysis of the methodology. The performance was verified through computer simulation using MATLAB Simulink and experiment.

능동형 제진 시스템의 설계 및 해석 (Design and Analysis of an Active Vibration Isolation System)

  • 문준희;박희재
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.647-650
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    • 2004
  • The modeling of an active vibration isolation system is accomplished by using the equivalent spring constant, mass and rotational Inertia of each component. The detailed model of the actuation module is successful for describing its frequency-domain performance but also too complicated to implement it to actual system for control so that the order of the model is reduced up to the degree that preserves its characteristic in the low frequency range. The reduced model is suitable for identifying the unknown system parameters such as damping constants of components. The overall isolation system is described by using the reduced model of the actuation module. The accurate model ing and system parameter identification that is essential for the control of the active vibration isolation system is attained successfully.

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압전작동기를 이용한 무인항공기 EO/IR 센서 마운트의 능동 진동 제어 (Active Vibration Control of UAV EO/IR Sensor Mount Using Piezoelectric Actuator)

  • 박동현;최승복
    • 한국소음진동공학회논문집
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    • 제18권12호
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    • pp.1278-1285
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    • 2008
  • This paper presents an inertia type of piezostack based active mount fur unmanned aero vehicle (UAV) camera system. After identifying the stiffness and damping properties of the rubber element and piezostack a mechanical model of the active mount system is established. The governing equation of mount is then derived and expressed in a state space form. Subsequently, a sliding mode controller which is robust to uncertain parameters is designed in order to reduce the vibration imposed according to the military specification associated with UAV camera mount system operation. Control performances such as acceleration and transmitted force are evaluated through both computer simulation and experimental implementation.

전기가변 고분자 소재를 이용한 응용소자 (Electro-active Polymer and Dielectric Elastomer Technology for Haptic Interface, Muscular Enhancement, and Tunable Optical Components)

  • 윤재웅;박승구;문성철
    • 전자통신동향분석
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    • 제34권4호
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    • pp.108-116
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    • 2019
  • Electro-active polymers and dielectric elastomers have many intriguing properties that enable smart interfaces and electrically tunable optical systems, such as haptic feedback devices, artificial muscles, and expansion-tunable optical elements. These device classes are of great interest owing to their promising roles in next-generation technologies including virtual or augmented reality, human sensing and muscular enhancement, and artificial skins. In this report, we review basic principles, current state-of-the-art techniques, and future prospects of electro-active and dielectric elastomer technology. We describe chemical and physical properties of the most promising polymer substances, essential elementary architectures for artificial muscle-like functionalities, and their applications to haptic interfaces, muscular enhancement, and focus-tunable optical elements.

EMRF를 이용한 개선된 Semi-Active Damper 개발 (Development of Improved Semi-Active Damper Using EMRF)

  • 전승곤
    • 한국지진공학회논문집
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    • 제26권4호
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    • pp.149-156
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    • 2022
  • Magneto-Rheological Fluid (MRF) is a functional fluid in which flow characteristics change into magnetic force due to its magnetic particles. When the semi-active control device does not use MRF for a long time, precipitation of magnetic particles and abnormal control force occur. Thus, Electro Magneto-Rheological Fluid (EMRF), which improves the precipitation of magnetic particles for MRF and exhibits existing control performance, was developed in this study. First, the optimal mix proportion ratio was selected by conducting a precipitation experiment and a controlled force test by varying the content of grease based on the existing MRF components. Also, EMRF was applied to the shear-type damper to evaluate the control performance when applied to the control device. The cylinder-type damper was developed to apply to the structure, and control performance evaluation was conducted. The result confirmed that the precipitation of the magnetic particles was improved, while the damper using EMRF exhibited excellent control performance.

Fuzzy Neural Network Active Disturbance Rejection Control for Two-Wheeled Self-Balanced Robot

  • Wang, Chao;Jianliang, Xiao;Zhang, Cheng
    • Journal of Information Processing Systems
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    • 제18권4호
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    • pp.510-523
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    • 2022
  • Considering the problems of poor control effect, weak disturbance rejection ability and adaptive ability of two-wheeled self-balanced robot (TWSBR) systems on undulating roads, this paper proposes a fuzzy neural network active disturbance rejection controller (FNNADRC), that is based on fuzzy neural network (FNN) for online correction of active disturbance rejection controller (ADRC)'s nonlinear control rate. Firstly, the dynamic model of the TWSBR is established and decoupled, the extended state observer (ESO) is used to compensate dynamically and linearize the upright and displacement subsystems. Then, the nonlinear PD control rate and FNN are designed, and the FNN is used to modify the control parameters of the nonlinear PD control rate in real time. Finally, the proposed control strategy is simulated and compared with the traditional ADRC and fuzzy active disturbance rejection controller (FADRC). The simulation results show that the control effect of the proposed control strategy is slightly better than ADRC and FADRC.

Dual-model Predictive Direct Power Control for Grid-connected Three-level Converter Systems

  • Hu, Bihua;Kang, Longyun;Feng, Teng;Wang, Shubiao;Cheng, Jiancai;Zhang, Zhi
    • Journal of Power Electronics
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    • 제18권5호
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    • pp.1448-1457
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    • 2018
  • Many researchers devote themselves to develop model-predictive direct power control (MPDPC) so as to accelerate the response speed of the grid-connected systems, but they are troubled its large computing amount. On the basis of MPDPC, dual MPDPC (DMPDPC) is presented in this paper. The proposed algorithm divides the conventional MPDPC into two steps. In the first step, the optimal sector is obtained, which contains the optimal switching state in three-level converters. In the second step, the optimal switching state in the selected sector is searched to trace reference active and reactive power and balance neutral point voltage. Simulation and experiment results show that the proposed algorithm not only decreases the computational amount remarkably but also improves the steady-state performance. The dynamic response of the DMPDPC is as fast as that of the MPDPC.