• 제목/요약/키워드: design variable

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ADSL용 DMT 시스템에 적합한 Variable step-size LMS equalizer의 ASIC 설계 (ASIC design of variable step-size LMS equalizer adapted DMT system for ADSL)

  • 하석기;박솔;김태훈;송재철;조병록
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.53-56
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    • 1999
  • In this thesis, the structure of equalizer adapted to DMT system for ADSL, its performance analysis is accomplished with computer simulation, and ASIC design. There are several methods in equalization, among them by using Variable Step-Size LMS algorithm to be concerned with convergence efficiency with training sequence, and its ASIC design.

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마이크로프로세서를 이용한 하이브리드 PWM 인버터의 설계 (A design of hybrid PWM inverter using microprocessor)

  • 노창주;임재문;박중순
    • Journal of Advanced Marine Engineering and Technology
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    • 제11권2호
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    • pp.37-50
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    • 1987
  • In an effort to conserve electric power, variable voltage variable frequency pulse width modulated (PWM) inverters are being applied increasingly to the variable speed control of the induction motors. The use of the PWM technique in motor drive applications is considered advantageous in many ways. For industrial applications, the PWM drive obtains its DC input through simple uncontrolled rectification of the commercial AC line and is favored for its good power factor, good efficiency, its relative freedom regulation problem, and mainly for its ability to operate the motor with nearly sinusoidal current waveforms. The purpose of this paper is to design a three phase natural sampled PWM inverter using microprocessor with simple control algorithm and hybrid control circuit has been built to implement this PWM scheme. In this system, the microprocessor can be used only for calculations directly related to motor control tasks by the design of hybrid circuit which sends PWM signals to the motor.

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신체의 Stiffened Plate 구조물의 모우드해석과 최적변경법에 관한 연구 (Study on the Optimum Modification and Modal Analysis of Stiffened Plate of Ship Hull Structure)

  • 박성현;박석주;고재용
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 제 25회 정기총회 및 추계학술발표회
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    • pp.51-58
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    • 2000
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization ,finite element method (FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristic by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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A controller design using modal decomposition of matrix pencil

  • Shibasato, Koki;Shiotsuki, Tetsuo;Kawaji, Shigeyasu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.492-492
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    • 2000
  • This paper proposes LQ optimal controller design method based on the modal decomposition. Here, the design problem of linear time-invariant systems is considered by using pencil model. The mathematical model based on matrix pencil is one of the most general representation of the system. By adding some conditions the model can be reduced to traditional system models. In pencil model, the state feedback is considered as an algebraic constraint between the state variable and the control input variable. The algebraic constraint on pencil model is called purely static mode, and is included in infinite mode. Therefore, the information of the constant gain controller is included in the purely static mode of the augmented system which consists of the plant and the control conditions. We pay attention to the coordinate transformation matrix, and LQ optimal controller is derived from the algebraic constraint of the internal variable. The proposed method is applied to the numerical examples, and the results are verified.

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적응형 관리도의 설계에 대한 비교연구 (A Comparative Study on the Design of Adaptive Control Charts)

  • 임태진
    • 품질경영학회지
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    • 제36권1호
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    • pp.7-19
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    • 2008
  • During the past two decades, a huge amount of research on adaptive control charts has been accomplished. Especially, variable sampling interval (VSI), variable sample size (VSS), and variable sample size and sampling interval (VSSI) charts have been focused by many researchers due to their simplicity and efficiency. On the other hand, the difference among notations, assumptions, methodologies may cause confusions in per forming further studies or practical implementations. This research analyses and compares diverse models so as to provide a unified view on statistical and economical characteristics. As a result, we perform comparative study on economical design models of VSI, VSS, and VSSI charts, respectively, We also present practical guidelines to utilize those adaptive control charts.

Design and Analysis of Fuzzy Control in a Variable Speed Refrigeration System

  • Hua, Li;Jeong, Seok-Kwon
    • International Journal of Air-Conditioning and Refrigeration
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    • 제15권2호
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    • pp.61-69
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    • 2007
  • This paper deals with fuzzy control with a feedforward compensator to progress both energy saving and coefficient of performance (COP) in a variable speed refrigeration system. Both the capacity and superheat are controlled simultaneously and independently in the system. By adopting the fuzzy theory, the controller design for the capacity and superheat is possible without depending on a dynamic model of the system. Moreover, the feedforward compensator of the superheat can reduce influence of the interfering loop between the capacity and superheat. Some experiments are conducted to design appropriate fuzzy controller by an iteration manner. The results show that the proposed fuzzy controller with the compensator can establish good control performances for the complicated refrigeration system in spite of its inherent strong non-linearity. Also, the fuzzy control performances were investigated by comparing to the model based PI control experimental results to evaluate transient behavior under the control.

A New Integral Variable Structure Controller For Incorporating Actuator Dynamics

  • Lee, Jung-Hoon
    • 전기전자학회논문지
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    • 제10권2호통권19호
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    • pp.97-102
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    • 2006
  • In this paper, a new simple integral variable structure controller is designed with incorporating the actuator dynamics. The formulation of the VSS (variable structure system) controller design includes integral augmented sliding surface and the dynamics of the actuator expressed as the state equation. An illustrative example is given to show the effectiveness of the developed controller.

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가변구조제어에 의한 조준경 고각 안정화 (Stabilization of elevation for gunner primary sight using variable structure control)

  • 김중완;이정규;김주상;이만형
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.643-647
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    • 1990
  • Gunner primary sight(GPS) stabilization system lays line of sight(LOS) to find out a target and transmits informations to the fire control system (FCS). In a moving vehicle, accuracy of LOS and FCS depends on the design of GPS and servomechanism system. The heavy vibration of vehicle on the severe off-road environment degenerates the stabilization capability of GPS. In this study, to stabilize of elevation for GPS using the variable structure control, we derived the dynamic equation of GPS system and designed the variable structure controller. Computer simulation results fulfilled the static and dynamic stability of GPS using the variable structure control.

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적응 순방향 이득을 갖는 이산가변 구조추종 제어기의 설계 (Design of a Discrete Variable Structure Tracking Controller with Adaptive Feedforward Gains)

  • 이성준;이강웅;최계근
    • 대한전자공학회논문지
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    • 제25권3호
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    • pp.262-268
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    • 1988
  • In this paper conditions are derived, which ensure the existence of a quasi-sliding mode on the control switching hyperplane in discrete variable structure control systems and also remove the reaching phase problem observed in continuous-time variable structure systems. In addition, a discrete variable structure tracking controller which has adaptive properties is devised based on these results. This controller has useful properties, such as small sensitivity to the variation of plant parameters and to disturbances and its performing speed is fast compared to that of other adaptive controller.

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