• 제목/요약/키워드: Fuzzy control systems

검색결과 2,199건 처리시간 0.027초

An Adaptive Virtual Machine Location Selection Mechanism in Distributed Cloud

  • Liu, Shukun;Jia, Weijia
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권12호
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    • pp.4776-4798
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    • 2015
  • The location selection of virtual machines in distributed cloud is difficult because of the physical resource distribution, allocation of multi-dimensional resources, and resource unit cost. In this study, we propose a multi-object virtual machine location selection algorithm (MOVMLSA) based on group information, doubly linked list structure and genetic algorithm. On the basis of the collaboration of multi-dimensional resources, a fitness function is designed using fuzzy logic control parameters, which can be used to optimize search space solutions. In the location selection process, an orderly information code based on group and resource information can be generated by adopting the memory mechanism of biological immune systems. This approach, along with the dominant elite strategy, enables the updating of the population. The tournament selection method is used to optimize the operator mechanisms of the single-point crossover and X-point mutation during the population selection. Such a method can be used to obtain an optimal solution for the rapid location selection of virtual machines. Experimental results show that the proposed algorithm is effective in reducing the number of used physical machines and in improving the resource utilization of physical machines. The algorithm improves the utilization degree of multi-dimensional resource synergy and reduces the comprehensive unit cost of resources.

신경망과 퍼지를 이용한 축산폐수처리플랜트의 실시간 원격 진단ㆍ제어 시스템 (Real-time Remote Diagnosis and Control System for the Piggery Wastewater Treatment Plant using Neural Networks and fuzzy Logic)

  • 서현용;김성신;배현;전병희;김창원
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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    • pp.107-110
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    • 2003
  • 산업의 발달과 인구의 증가로 인한 물 사용량 증가와 다양한 폐수들이 끊임없이 발생하고 있다. 회사나 공장들은 이러한 폐수를 처리하기 위한 하ㆍ폐수처리장의 효율적인 운전을 위하여 관리ㆍ제어 시스템을 도입하고 있는 추세이다. 본 논문에서는 김해에 설치되어 있는 축산 폐수를 처리하는 파일럿 플랜트의 공정상태를 원격으로 관리할 수 있는 모니터링 시스템을 바탕으로 퍼지와 신경망을 이용한 실시간 원격 진단 및 제어 시스템을 설계하였다. 또한 여러 경우의 고장 사례를 원격 진단ㆍ제어 시스템에 접목시킴으로써 진단시스템의 성능을 더욱 향상 시켰다. 이러한 진단ㆍ제어 시스템을 이용하여 관리자는 공정상태를 항상 모니터링 할 수 있으며, 진단ㆍ제어 시스템에서 제공하는 경고 및 제어 값을 축산폐수플랜트에 전송함으로써 공정을 보다 효율적이고 안정적으로 진단ㆍ제어할 수 있다.

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A Multiagent System for Workflow-Based Bioinformatics Tool Integration

  • Sohn, Bong-Ki;Lee, Keon-Myung;Kim, Hak-Joon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권2호
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    • pp.133-137
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    • 2003
  • Various bioinformatics tools for biological data processing have been developed and most of them are available in public. Most bioinformatics works are carried out by a composite application of those tools. Several integration approaches have been proposed for easy use of the tools. This paper proposes a new multi agent system to integrate bioinformatics tools in the perspective of workflow since the composite applications of tools can be regarded as workflows. For the easy integration, the proposed system employs wrapper agents for existing tools, uses XML-based messages in the inter-agent communication, and agents are supposed to extract necessary information from the received messages. This allows new tools to be easily added on the integration framework. The proposed method allows various control structures in workflow definition and provides the progress monitoring capability of the on-going workflows. In particular, agents in this system have the rule-based architecture which allows the defined rule set to be a special role agent. This feature provides fast and flexible agent development to aid in managing the complexity of bioinformatics application. This system has been partially implemented and has been proven to be a viable implementation for workflow-based bioinformatics tool integration.

Design and Implementation of the EEIS Considering the Load of DB Server

  • Kim, Chang-Geun;Park, Byeong-Jin;Tack, Han-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권1호
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    • pp.37-43
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    • 2003
  • Current Internet system of the entrance exam information to the university that is depending on searching key to solve the overloaded problem in the network and DB server or other tools to support HTML edit, haven't satisfied user's wants by supplying uniformed searching system. So this thesis will establish EEIS(Entrance Examination Information System) to prevent database overload phenomena when many users request a great amount of data at the same time and improve the decrease of speed and overload problem in DB server. EEIS playa role of bridge between outside client and DB server by placing VVS(Virtual View Server) between web server and DB server. By that method this system give users several usefulness in convenience and variety by supplying realtime data searching function to user. EEIS also give inner system manager more efficiency and speed in control the management system by solving those problem. This system is design and implementation to satisfy user's desire and give them more convenience and bring up the confidence of university that adopt this system at the end.

클러스터링 기반 뉴로-퍼지 모델링 학습 (Neuro-Fuzzy Modeling Learning method based on Clustering)

  • 김승석;곽근창;이대종;김성수;유정웅;김주식;김용태
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2005년도 춘계학술대회 학술발표 논문집 제15권 제1호
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    • pp.289-292
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    • 2005
  • 본 논문에서는 클러스터링과 뉴로-퍼지 모델링을 동시에 실시하는 학습 기법을 제안하였다. 클러스터링을 이용하여 뉴로-퍼지 모델링을 실시하는 일반적인 경우, 클러스터링 학습을 실시한 후 학습된 파라미터를 뉴로-퍼지 모델의 초기 파라미터로 설정하고 모델을 다시 학습하는 방법을 취한다. 즉 클러스터링에서 클러스터의 수를 구하고 파라미터를 최적화함으로써 초기 구조동정과 파라미터 동정을 실시하며 이를 다시 뉴로-퍼지 모델에서 세부적인 파라미터 동정을 실시하는 것이다. 또한 모델에서의 학습은 출력데이터의 오차를 이용한 오차미분기반 학습으로 전제부 소속함수 파라미터를 수정하는 방법을 이용한다. 이 경우 클러스터링의 영향과 모델의 영향이 각각 별개로 고려될 수 있다. 따라서 본 논문에서는 클러스터링을 전제부 소속함수로 부여하고 클러스터링의 학습에 뉴로-퍼지 모델을 이용하면서 또한 모델의 학습에 클러스터링을 직접 적용하는 클러스터링 기반 뉴로-퍼지 모델링을 제안하였으며 이 경우 클러스터링의 학습과 모델의 학습이 동시에 이루어지며 뉴로-퍼지 모델에서 클러스터링의 효과를 직접적으로 확인할 수 있다. 제안된 방법의 유용성을 시뮬레이션을 통하여 보이고자 한다.

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Integrated Task Planning based on Mobility of Mobile Manipulator (M2) Platform

  • Jin, Tae-Seok;Kim, Hyun-Sik;Kim, Jong-Wook
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제9권3호
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    • pp.206-212
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    • 2009
  • This paper presents an optimized integrated task planning and control approach for manipulating a nonholonomic robot by mobile manipulators. Then, we derive a kinematics model and a mobility of the mobile manipulator(M2) platform considering it as the combined system of the manipulator and the mobile robot. to improve task execution efficiency utilizing the redundancy, optimal trajectory of the mobile manipulator(M2) platform are maintained while it is moving to a new task point. A cost function for optimality can be defined as a combination of the square errors of the desired and actual configurations of the mobile robot and of the task robot. In the combination of the two square errors, a newly defined mobility of a mobile robot is utilized as a weighting index. With the aid of the gradient method, the cost function is minimized, so the path trajectory that the M2 platform generates is optimized. The simulation results of the 2 ink planar nonholonomic M2 platform are given to show the effectiveness of the proposed algorithm.

스마트 스페이스 구축을 위한 강인 지능형 디지털 제어기 개발 (Development of Robust Intelligent Digital Controller for Smart Space)

  • 주영훈
    • 한국지능시스템학회논문지
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    • 제18권1호
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    • pp.60-65
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    • 2008
  • 본 논문에서는 강인 디지털 제어기를 통한 스마트 스페이스의 안정도에 대해 논의하고자 한다. 제안된 제어기 설계 방법은 지능형 디지털 재 설계 기법을 적용하는 것이다. 좀 더 구체적으로, 불확실성 및 비선형성이 포함된 아날로그 시스템을 Takagi-Sugeno 퍼지 모델을 사용하여 나타낸다. 그리고 전역적 지능형 디지털 재 설계를 위하여 해당 문제를 볼록 최적화 관점으로 변환 한 후, 에러가 가질 수 있는 놈의 영역을 최소화하여 상태 정합을 이루고자 하였다. 전역적 접근을 통해 정리된 식은 선형 행렬 부등식으로 나타나게 된다. 마지막으로, 설계된 제어기를 HVAC (Heating, ventilating, and air conditioning) 시스템에 적용함으로써 효율성을 입증하고자 한다.

단기 물 수요예측 시뮬레이터 개발과 예측 알고리즘 성능평가 (Development of Water Demand Forecasting Simulator and Performance Evaluation)

  • 신강욱;김주환;양재린;홍성택
    • 상하수도학회지
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    • 제25권4호
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    • pp.581-589
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    • 2011
  • Generally, treated water or raw water is transported into storage reservoirs which are receiving facilities of local governments from multi-regional water supply systems. A water supply control and operation center is operated not only to manage the water facilities more economically and efficiently but also to mitigate the shortage of water resources due to the increase in water consumption. To achieve the goal, important information such as the flow-rate in the systems, water levels of storage reservoirs or tanks, and pump-operation schedule should be considered based on the resonable water demand forecasting. However, it is difficult to acquire the pattern of water demand used in local government, since the operating information is not shared between multi-regional and local water systems. The pattern of water demand is irregular and unpredictable. Also, additional changes such as an abrupt accident and frequent changes of electric power rates could occur. Consequently, it is not easy to forecast accurate water demands. Therefore, it is necessary to introduce a short-term water demands forecasting and to develop an application of the forecasting models. In this study, the forecasting simulator for water demand is developed based on mathematical and neural network methods as linear and non-linear models to implement the optimal water demands forecasting. It is shown that MLP(Multi-Layered Perceptron) and ANFIS(Adaptive Neuro-Fuzzy Inference System) can be applied to obtain better forecasting results in multi-regional water supply systems with a large scale and local water supply systems with small or medium scale than conventional methods, respectively.

A new approach to deal with sensor errors in structural controls with MR damper

  • Wang, Han;Li, Luyu;Song, Gangbing;Dabney, James B.;Harman, Thomas L.
    • Smart Structures and Systems
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    • 제16권2호
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    • pp.329-345
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    • 2015
  • As commonly known, sensor errors and faulty signals may potentially lead structures in vibration to catastrophic failures. This paper presents a new approach to deal with sensor errors/faults in vibration control of structures by using the Fault detection and isolation (FDI) technique. To demonstrate the effectiveness of the approach, a space truss structure with semi-active devices such as Magneto-Rheological (MR) damper is used as an example. To address the problem, a Linear Matrix Inequality (LMI) based fixed-order $H_{\infty}$ FDI filter is introduced and designed. Modeling errors are treated as uncertainties in the FDI filter design to verify the robustness of the proposed FDI filter. Furthermore, an innovative Fuzzy Fault Tolerant Controller (FFTC) has been developed for this space truss structure model to preserve the pre-specified performance in the presence of sensor errors or faults. Simulation results have demonstrated that the proposed FDI filter is capable of detecting and isolating sensor errors/faults and actuator faults e.g., accelerometers and MR dampers, and the proposed FFTC can maintain the structural vibration suppression in faulty conditions.

Face Detection for Automatic Avatar Creation by using Deformable Template and GA

  • Park, Tae-Young;Lee, Ja-Yong;Kang, Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1534-1538
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    • 2005
  • In this paper, we propose a method to detect contours of a face, eyes, and a mouth of a person in the color image in order to make an avatar automatically. First, we use the HSI color model to exclude the effect of various light conditions, and find skin regions in the input image by using the skin color defined on HS-plane. And then, we use deformable templates and genetic algorithm (GA) to detect contours of a face, eyes, and a mouth. Deformable templates consist of B-spline curves and control point vectors. Those represent various shapes of a face, eyes and a mouth. GA is a very useful search algorithm based on the principals of natural selection and genetics. Second, the avatar is automatically created by using GA-detected contours and Fuzzy C-Means clustering (FCM). FCM is used to reduce the number of face colors. In result, we could create avatars which look like handmade caricatures representing user's identity. Our approach differs from those generated by existing methods.

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