• 제목/요약/키워드: fuzzy stability

검색결과 621건 처리시간 0.025초

퍼지-AHP를 활용한 구직자의 기업평가 모형 개선 연구 (An Improved Company Assessment Framework Based on Job Seekers' Preferences Using Fuzzy-Analytic Hierarchy Process(AHP))

  • 이충석;류옥현
    • 산업경영시스템학회지
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    • 제38권1호
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    • pp.90-100
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    • 2015
  • This study is conducted to suggest ways to mitigate the mismatch phenomenon between job seekers who want to find right company for themselves and companies looking for appropriate new employees. For this purpose, this study improves the company assessment framework reflecting job seekers interests by using fuzzy analytic hierarchy process. The improved evaluation framework is a three-level hierarchical structure, where there are 4 groups at the top level, 12 factors at the intermediate level and 36 indexes at the bottom level. For the empirical analysis of the applicants preferences based on the improved model, a survey for F-AHP analysis is carried out to university students and then priorities of components in the evaluation model are calculated. Moreover, the differences of priority of the company assessment framework are analyzed for different genders, college years, and major divisions. The results show that job seekers' most concerning factors are wages, stability, working environments, and labor deal, which are ranked highly in this order and the differences in preferences for each type of job seekers (genders, college years, and major divisions) are obvious. The results also show that the male prefers wages to environment, on the other hand female does working environment to wages.

불확실한 비선형 계통에 대한 SPR 조건이 필요 없는 적응 퍼지 관측기 (Adaptive Fuzzy Observer without SPR Condition for Uncertain Nonlinear Systems)

  • 박장현;김성환
    • 전기전자학회논문지
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    • 제7권2호
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    • pp.156-165
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    • 2003
  • 본 논문은 불확실한 비선형 계통에 대해서 강인한 적응 퍼지 관측기를 설계하는 방법을 제시한다. 새로 제시하는 관측기는 관측기 설계시 관측오차의 동특성식이 SPR (strictly positive real)이어야 한다는 조건이 불필요하다. 또한 불확실한 항에 대한 유계상수도 추정하는 알고리듬을 사용하여 강인항의 이득값을 설계자가 미리 결정할 필요가 없게 된다. 설계된 관측기를 포함한 전체 폐루프 계통에 대해서 리아프노브 안정도를 증명하였으며 관측오차를 포함한 계통의 모든 신호들의 반전역적 유계(semi-global uniform ultimate boundedness)임을 증명하였다. 이론적으로 도출된 결과를 mass-spring-damper 계통에 대한 모의실험을 수행하여 제안된 관측기의 효율성과 성능을 보였다.

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퍼지제어기를 이용한 유도전동기의 센서리스 속도제어에 관한 연구 (Sensorless Control of Induction Motor with Fuzzy Controller)

  • 김성환;오상호;권영안
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.3-5
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    • 1996
  • A sensorless drive of induction motor has several advantage: low cost and availability in a harsh environment. Most of sensorless control schemes are based on the direct estimation of rotor speed from state observer. This study proposes a new sensorless control scheme. The proposed scheme is based on a reference model control which the error between the model and plant outputs decays to zero as time proceeds. The actuating signal is calculated from the fuzzy controller which increases the system stability and robustness. The simulation results indicate a good dynamic performance.

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능동전륜조향장치 및 능동후륜제동장치의 통합제어기 개발 (Development of an Integrated Control System between Active Front Wheel System and Active Rear Brake System)

  • 송정훈
    • 한국자동차공학회논문집
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    • 제20권6호
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    • pp.17-23
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    • 2012
  • An integrated dynamic control (IDCF) with an active front steering system and an active rear braking system is proposed and developed in this study. A fuzzy logic controller is applied to calculate the desired additional steering angle and desired slip of the rear inner wheel. To validate IDCF system, an eight degree of freedom, nonlinear vehicle model and a sliding mode wheel slip controller are also designed. Various road conditions are used to test the performance. The results show that the yaw rate of IDCF vehicle followed the reference yaw rate and reduced the body slip angle, compared with uncontrolled vehicle. Thus, the IDCF vehicle had enhanced lateral stability and controllability.

다기계통 안정화를 위한 강인한 적응 퍼지 제어기 설계 (Design of Robust Adaptive Fuzzy Controller for Multi-Machine Power System)

  • 박장현;박영환;허성회;최진호;박귀태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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    • pp.615-617
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    • 1999
  • In this paper, we present a decentralized robust adaptive fuzzy controller for the transient stability and voltage regulation of a multimachine power system under a sudden fault. Power systems have uncertain dynamics due to various effects such as lightning, severe storms and equipment failure in addition to interconnections between generators. Hence a robust controller to deal with these uncertainties is needed. Simulation results show that satisfactory performance is achieved by the proposed controller.

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퍼지제어에 의한 PV시스템의 PCS 출력특성 (PCS Power Characteristics of PV System by Fuzzy Controller)

  • 문은아;임흥우;백형래;조금배;오금곤;임양수;김평호
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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    • pp.147-150
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    • 2004
  • Maximum power point tracking for PV systems traditionally uses either perturbation and observation method or incremental conductance method. Both methods require modulation of the output voltage and this leads to significant power loss. In this paper, a method, which senses output circuit voltage and short circuit current and use the above two parameters for optimum control with a fuzzy controller, is introduced. The short circuit current of PV cell represents illumination, and the output circuit voltage carry on information about the temperature. PCS(power conditioning system) is controlled not only feed to inverter for stability voltage variation despite of variety external environment, but also operate in order to feeding voltage and current at maximum power point by boost type chopper.

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퍼지 알고리즘을 이용한 자율주행 이동로봇의 설계에 관한 연구 (A Study on Autonomous Driving Mobile Robot by Using Fuzzy Algorith)

  • 서현재;임영도
    • 한국통신학회논문지
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    • 제31권4B호
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    • pp.278-284
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    • 2006
  • 본 논문에서는 퍼지 알고리즘을 사용하여 지능형 자율주행로봇을 설계하였다. 설계된 로봇은 이동시 장애물을 인식하여 이를 회피하며 안전하게 도달하는데 목적이 있다. 또한 로봇의 이동에 있어서 로봇의 안정성과 주행성의 성능을 높이기 위해 보조 바퀴에 서스펜션을 장착하였다. 이렇게 설계된 지능형 자율주행로봇은 병원이나 빌딩내부의 좁은 실내에서 노약자나 장애인이 원하는 목적지 까지 안전하게 갈수 있다.

전력계통 안정도 향상을 위한 SVC용 퍼지제어기의 설계 (Design of SVC Fuzzy Logic Controller for Improving Power System Stability)

  • 정근영;황기현;손종훈;김형수;문경준;박준호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 A
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    • pp.221-223
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    • 2000
  • This paper describes the design of SVC fuzzy logic controller (SVC-FLC) using adaptive evolutionary algorithm and we tuned the gain of input-output variables of SYC-FLC using it. We performed the nonlinear simulation on an single-machine infinite system to prove the efficiency of the proposed method. The proposed SYC-FLC showed the better performance than PD controller in terms of the settling time and damping effect, for system operation condition used in evaluating the robustness and three phase grounding default in cases of nominal loading used in tuning SVC-FLC for a single-machine infinite system.

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VCR용 드럼 모터의 퍼지 속도/위상 제어기 설계 (Design of fuzzy speed/phase controller for drum motor in home VCR)

  • 박귀태;이기상;박태홍;배상욱;이상락
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.457-462
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    • 1991
  • Recently, digital techniques have been applied to servo systems of the home VCR, which result in high accuracy, high stability and a small number of parts required. The servo systems are now becoming more compex because the latest home VCRs are stringly required to have many functions. Given these circumstances, software servo concepts were introduced to the VCR servo system with microprocessor. But there are some difficulties in the conventional digital PID controller, eg. caculating the exact gains or dynamics. In this paper, we introduce FLC(Fuzzy Logic Controller) to the speed/phase control for VCR drum motor. To show the usefulness of the proposed controller, some studies are discussed by simulation and experiment.

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Advanced controller design for AUV based on adaptive dynamic programming

  • Chen, Tim;Khurram, Safiullahand;Zoungrana, Joelli;Pandey, Lallit;Chen, J.C.Y.
    • Advances in Computational Design
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    • 제5권3호
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    • pp.233-260
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    • 2020
  • The main purpose to introduce model based controller in proposed control technique is to provide better and fast learning of the floating dynamics by means of fuzzy logic controller and also cancelling effect of nonlinear terms of the system. An iterative adaptive dynamic programming algorithm is proposed to deal with the optimal trajectory-tracking control problems for autonomous underwater vehicle (AUV). The optimal tracking control problem is converted into an optimal regulation problem by system transformation. Then the optimal regulation problem is solved by the policy iteration adaptive dynamic programming algorithm. Finally, simulation example is given to show the performance of the iterative adaptive dynamic programming algorithm.