• 제목/요약/키워드: Feedback Mechanism

검색결과 402건 처리시간 0.024초

지역사회서비스 품질, 만족도, 재이용의사의 동태성에 관한 연구 (A Study on the Dynamics of the Quality, Satisfaction, and Reuse Intention of Community Social Services)

  • 조성숙
    • 한국시스템다이내믹스연구
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    • 제13권2호
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    • pp.73-91
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    • 2012
  • This study aims to comprehensively understand the dynamics between the factors related to service quality, satisfaction and reuse intention. The contents of the study are as follows. First, it draws the limitations of the existing studies by reviewing the literature related to the relationships between service quality, satisfaction and reuse intention. Second, it highlights the characteristics of System Dynamics as a means of overcoming their shortcomings as well as examining the dynamic mechanism of the relevant factors. Third, it explores the feedback loops of the relevant key variables and the feedback structure of the system. Lastly, it concludes with the suggestions and implications of the key research findings. This study is expected to emphasize the importance of the feedback mechanism operating around the service quality, satisfaction, and reuse intention. Further, the causal loop diagram developed can be a basic material for the diverse levels of governments as well as service providers to refer to for improving the service quality of Community Social Service Investment Program.

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APPROXIMATION SCHEME FOR A CONTROL SYSTEM

  • KANG, SUNG-KWON
    • 호남수학학술지
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    • 제16권1호
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    • pp.103-109
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    • 1994
  • Piezoceramic patches as collocated actuator and sensors are widely used in mechanical control systems. An approximation scheme for computing feedback gains arising in heat flux stabilization problem with such control mechanism is introduced. The scheme is based on a finite element method and a variational approach.

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Reducing Feedback Overhead in Opportunistic Scheduling of Wireless Networks Exploiting Overhearing

  • Baek, Seung-Jun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권2호
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    • pp.593-609
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    • 2012
  • We propose a scheme to reduce the overhead associated with channel state information (CSI) feedback required for opportunistic scheduling in wireless access networks. We study the case where CSI is partially overheard by mobiles and thus one can suppress transmitting CSI reports for time varying channels of inferior quality. We model the mechanism of feedback suppression as a Bayesian network, and show that the problem of minimizing the average feedback overhead is NP-hard. To deal with hardness of the problem we identify a class of feedback suppression structures which allow efficient computation of the cost. Leveraging such structures we propose an algorithm which not only captures the essence of seemingly complex overhearing relations among mobiles, but also provides a simple estimate of the cost incurred by a suppression structure. Simulation results are provided to demonstrate the improvements offered by the proposed scheme, e.g., a savings of 63-83% depending on the network size.

면역 피드백 메카니즘과 경사감소학습에 기초한 비선형 적응 PID 제어기 설계 (Nonlinear Adaptive PID Controller Desist based on an Immune Feedback Mechanism and a Gradient Descent Learning)

  • 박진현;최영규
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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    • pp.113-117
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    • 2002
  • PID controllers, which have been widely used in industry, have a simple structure and robustness to modeling error. But it is difficult to have uniformly good control performance in system parameters variation or different velocity command. In this paper, we propose a nonlinear adaptive PR controller based on an Immune feedback mechanism and a gradient descent teaming. This algorithm has a simple structure and robustness to system parameters variation. To verify performances of the proposed nonlinear adaptive PID controller, the speed control of nonlinear DC motor Is peformed. The simulation results show that the proposed control systems are effective in tracking a command velocity under system parameters variation

신경회로망에 의한 미지의 구조를 가진 시변동적시스템의 지능적 예측제어 (Intelligent Predictive Control of Time-Varying Dynamic Systems with Unknown Structures Using Neural Networks)

  • 오세준
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권3호
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    • pp.286-286
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    • 1996
  • A neural predictive tracking system for the control of structure-unknown dynamic system is presented. The control system comprises a neural network modelling mechanism for the the forward and inverse dynamics of a plant to be controlled, a feedforward controller, feedback controller, and an error prediction mechanism. The feedforward controller, a neural network model of the inverse dynamics, generates feedforward control signal to the plant. The feedback control signal is produced by the error prediction mechanism. The error predictor adopts the neural network models of the forward and inverse dynamics. Simulation results are presented to demonstrate the applicability of the proposed scheme to predictive tracking control problems.

신경회로망에 의한 미지의 구조를 가진 시변동적시스템의 지능적 예측제어 (Intelligent Predictive Control of Time-Varying Dynamic Systems with Unknown Structures Using Neural Networks)

  • 오세준
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권3호
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    • pp.154-161
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    • 1996
  • A neural predictive tracking system for the control of structure-unknown dynamic system is presented. The control system comprises a neural network modelling mechanism for the the forward and inverse dynamics of a plant to be controlled, a feedforward controller, feedback controller, and an error prediction mechanism. The feedforward controller, a neural network model of the inverse dynamics, generates feedforward control signal to the plant. The feedback control signal is produced by the error prediction mechanism. The error predictor adopts the neural network models of the forward and inverse dynamics. Simulation results are presented to demonstrate the applicability of the proposed scheme to predictive tracking control problems.

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보행 시작 시 원심성 근육 수축 조절 (Muscle Eccentric Control in Gait Initiation)

  • 김형동
    • 한국전문물리치료학회지
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    • 제8권4호
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    • pp.81-89
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    • 2001
  • 전시냅스 억제(presynaptic inhibition)와 동시냅스 억제(homosynaptic depression)는 보행 시에 분절반사(segmental reflex)를 조절하는 두 가지 독립적인 기전이다. 근방추 피드백(feedback)은 전시냅스 억제(inhibition)를 통해 보행 시 원심성 근육 수축기에서 적절이 조절될 수 있다. 이러한 전시냅스 억제 작용은 H-reflex의 강도로 나타내질 수 있는데, 원심성 근육 수축기 동안 H-reflex의 강도가 약해지는 것으로 보아 전시냅스 억제 작용은 증가되는 것으로 보여진다. 근방추 구심성 피드백(feedback) 역시 동시냅스 억제를 통해서 조절될 수 있다. 따라서 전시냅스와 동시냅스 억제는 보행 시작 중에 반사의 기전을 조절하는 중요한 역할을 한다. 반사의 조절 기전은 알파(alpha) 운동 신경원의 흥분도와 더불어 상위 척수의 기전들을 통해서 영향받고 조절된다. 경직성 마비 환자들은 초기의 입각기, 혹은 유각기 중에 손상된 비정상 비복근 H-reflex 조절기전을 보여준다. 이러한 비정상적인 조절기전은 발바닥의 말초신경을 자극함으로써 부분적으로 회복될 수 있다.

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