• 제목/요약/키워드: complex adaptive systems

검색결과 167건 처리시간 0.027초

Complex Process Control using the Adaptive Neural Fuzzy Inference System

  • Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.351-351
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    • 2000
  • Since the heat exchange system, such as the boiler of power plant, gas turbine, and radiator require an application of intelligent control system for a high rate heat efficiency and the efficiency of these systems is depended on the control methods it is important for operator to understand control system of these systems and intelligent control technologies. In order to properly apply control equipment and intelligent technology to these process control systems, it is necessary to understand fuzzy, neural network, genetics, and immune as well as the basic aspects and operation principle of the process that relate control, interrelationships of the process characteristics, and the dynamics that are involved. Generally, since PID controllers are used in these systems it is difficult far engineer to understand both the complex dynamics and the intelligent control method. In this paper, we design an effective experimental system for the intelligent control education and analyze its characteristics through experimental system and each intelligent method to study how they can learn intelligent control system by experiments.

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The Short Time Spectra Analysis System Using The Complex LMS Algorithm and It's Applications

  • Umemoto, Toshitaka;Fujisawa, Shoichiro;Yoshida, Takeo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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    • pp.58-63
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    • 1998
  • B.Widrow established fundamental relations between the least-mean-square (LMS) algorithm and the digital Fourier transform[1]. By extending these relations, we proposed the short time spectra analysis system using the LMS algorithm[2]. In that paper, we used the normal LMS algorithm on the thought of dealing with only real analytical signal. This algorithm minimizes the real mean-square by recursively altering the complex weight vector at each sampling instant. But, the short time spectra analysis sometimes deals with the complex signal that is outputted from complex analog filter. So, in order to optimize and develop this methods, furthermore it is necessary to derive an algorithm for the complex analytical signal. In this paper, we first discuss the new adaptive system for the spectra analysis using the complex LMS algorithm and then derive convergence condition, time constant of coefficient adjustment and frequency resolution by extending the discussion. Finally, the effectiveness of the proposed method is experimentally demonstrated by applying it to the measurement of transfer performance on complex analog filter.

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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.

Exploring Knowledge Processing in a Social Complex Adaptive Organization : Wikipedia through the Lens of the LIFE Model

  • Faucher, Jean-Baptiste P.L.;Everett, Andre M.;Lawson, Rob
    • Journal of Information Technology Applications and Management
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    • 제18권1호
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    • pp.15-39
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    • 2011
  • A deeper understanding of how organizations behave as social complex adaptive systems is needed. In this paper we demonstrate how the Leadership Invigorating Flows of Energies model can help with this understanding. The model highlights the role of emergent leadership as a force encouraging the creation, diffusion, and utilization of knowledge through self-organizing mechanisms. We illustrate our approach by examining Wikipedia and show how it can be described as a social CAS. Our analysis of Wikipedia describes how emerging intrapreneurship behaviors result in dynamic flows of knowledge and self-organizing feedback mechanisms across the organization. We provide implications for organization studies and present evidence to support claims made by advocates of complexity theory. We conclude by proposing that Wikipedia can be seen as a new form of organization, and finish with a brief note highlighting a possible way forward.

확장 칼만 필터 학습 방법 기반 웨이블릿 신경 회로망을 이용한 비선형 시스템의 간접 적응 제어 (Indirect Adaptive Control of Nonlinear Systems Using a EKF Learning Algorithm Based Wavelet Neural Network)

  • 김경주;최윤호;박진배
    • 한국지능시스템학회논문지
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    • 제15권6호
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    • pp.720-729
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    • 2005
  • 본 논문에서는 미지의 비선형 시스템을 제어하기 위해 웨이블릿 신경 회로망을 이용한 간접 적응 제어기를 설계한다. 제안 된 간접 적응 제어기는 웨이블릿 신경 회로망을 이용한 동정 모델과 제어기로 구성된다. 여기서 동정 모델과 제어기에 사용되는 웨이블릿 신경 회로망은 시간과 주파수에 대한 정보를 동시에 포함하는 웨이블릿의 특성을 가지고 있기 때문에 다층구조 신경회로망과 방사 기저 함수 신경회로망에 보다 더 빠른 수렴특성을 보인다. 웨이블릿 신경 회로망의 학습방법은 경사 하강법, 유전알고리듬, DNA 기법등 여러 가지가 있으나, 본 논문에서는 확장 칼만 필터를 기반으로 한 학습 방법을 제안한다. 확장 칼만 필터 학습 방법은 계산이 복잡하기는 하지만 학습되어 갱신되는 파라미터의 이전 데이터 정보를 이용하는 특성 때문에 매우 빠른 수렴 특성을 보인다. 본 논문에서는 Buffing 시스템과 1축 머니퓰레이터에 대한 컴퓨터 모치실험을 통해 제안한 확장 칼만 필터 학습 방법을 이용한 간접 적응 제어기가 일반적인 경사 하강법을 이용한 경우보다 우수함을 보인다.

Simulation of a Laser Tomography Adaptive Optics with Rayleigh Laser Guide Stars for the Satellite Imaging System

  • Ahn, Kyohoon;Lee, Sung-Hun;Park, In-Kyu;Yang, Hwan-Seok
    • Current Optics and Photonics
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    • 제5권2호
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    • pp.101-113
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    • 2021
  • Adaptive optics (AO) systems are becoming more complex to improve their optical performance and enlarge their field of view, so it is a hard and time consuming process to set up and optimize the components of AO systems with actual implementation. However, simulations allow AO scientists and engineers to experiment with different optical layouts and components without needing to obtain and prepare them physically. In this paper, we introduce a new AO simulation named the Korea Adaptive Optics Simulation (KAOS), independently developed by LIG Nex1. We verified the performance of KAOS by comparing with other AO simulation tools. In the comparison simulation, we confirmed the results from KAOS and other AO simulation tools were very similar. Also, we proposed a laser tomography AO system with five Rayleigh laser guide stars (LGSs) optimized by using KAOS to overcome the disadvantages of the AO system with a single sodium LGS for the satellite imaging system. We verified the performance of the proposed AO system using KAOS, and the simulation result showed averaged Strehl ratio of 0.37.

클러스터 적응주기 모델에 대한 비판적 검토 (Critical Review on the Cluster Adaptive Cycle Model)

  • 전지혜;이철우
    • 한국경제지리학회지
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    • 제20권2호
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    • pp.189-213
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    • 2017
  • 본 연구는 클러스터 진화의 분석에 있어서 클러스터 적응주기 모델의 의의와 한계점을 비판적으로 검토하고, 이를 토대로 향후 클러스터 진화 분석을 위한 연구 과제를 제시하고자 하였다. 1980년대 이전까지 클러스터를 비롯한 산업집적지 연구는 특정 시점에서 경제 공간의 양상에 주목하는 '정태적 관점'을 기초로 이루어졌지만, 최근에는 '복잡적 응계'의 '진화'에 주목하는 '동태적 연구'로 패러다임이 전환되었다. 이에 역동적 지속적으로 진화하는 클러스터에 적절한 분석도구로 적응주기 모델이 주목받게 되었으나, 클러스터 및 그 진화의 속성에 맞게 수정 및 보완되어 클러스터 적응주기 모델이 등장하게 되었다. 클러스터 적응주기 모델은 자원축적, 상호의존성 그리고 회복력의 측면에서 클러스터 진화의 특성을 규명하고, 클러스터 진화 경로를 6가지로 구분하여 살펴 볼 수 있는 포괄적인 분석틀이지만, 모델의 확대 및 심화를 위해서 이론적 경험적 연구 측면에서 더욱 활발한 논의와 보완이 요구된다. 따라서 향후 클러스터 진화 분석에 있어서의 연구 과제로는 클러스터 진화 모델의 구체화 및 정교화, 회복력 개념의 강조 그리고 경험적 연구를 통한 모델의 적용가능성과 유용성의 검증을 제시하고자 한다.

Low-Complexity MIMO Detection Algorithm with Adaptive Interference Mitigation in DL MU-MIMO Systems with Quantization Error

  • Park, Jangyong;Kim, Minjoon;Kim, Hyunsub;Jung, Yunho;Kim, Jaeseok
    • Journal of Communications and Networks
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    • 제18권2호
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    • pp.210-217
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    • 2016
  • In this paper, we propose a low complexity multiple-input multiple-output (MIMO) detection algorithm with adaptive interference mitigation in downlink multiuser MIMO (DL MU-MIMO) systems with quantization error of the channel state information (CSI) feedback. In DL MU-MIMO systems using the imperfect precoding matrix caused by quantization error of the CSI feedback, the station receives the desired signal as well as the residual interference signal. Therefore, a complexMIMO detection algorithm with interference mitigation is required for mitigating the residual interference. To reduce the computational complexity, we propose a MIMO detection algorithm with adaptive interference mitigation. The proposed algorithm adaptively mitigates the residual interference by using the maximum likelihood detection (MLD) error criterion (MEC). We derive a theoretical MEC by using the MLD error condition and a practical MEC by approximating the theoretical MEC. In conclusion, the proposed algorithm adaptively performs interference mitigation when satisfying the practical MEC. Simulation results show that the proposed algorithm reduces the computational complexity and has the same performance, compared to the generalized sphere decoder, which always performs interference mitigation.

Research on Low-energy Adaptive Clustering Hierarchy Protocol based on Multi-objective Coupling Algorithm

  • Li, Wuzhao;Wang, Yechuang;Sun, Youqiang;Mao, Jie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권4호
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    • pp.1437-1459
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    • 2020
  • Wireless Sensor Networks (WSN) is a distributed Sensor network whose terminals are sensors that can sense and check the environment. Sensors are typically battery-powered and deployed in where the batteries are difficult to replace. Therefore, maximize the consumption of node energy and extend the network's life cycle are the problems that must to face. Low-energy adaptive clustering hierarchy (LEACH) protocol is an adaptive clustering topology algorithm, which can make the nodes in the network consume energy in a relatively balanced way and prolong the network lifetime. In this paper, the novel multi-objective LEACH protocol is proposed, in order to solve the proposed protocol, we design a multi-objective coupling algorithm based on bat algorithm (BA), glowworm swarm optimization algorithm (GSO) and bacterial foraging optimization algorithm (BFO). The advantages of BA, GSO and BFO are inherited in the multi-objective coupling algorithm (MBGF), which is tested on ZDT and SCH benchmarks, the results are shown the MBGF is superior. Then the multi-objective coupling algorithm is applied in the multi-objective LEACH protocol, experimental results show that the multi-objective LEACH protocol can greatly reduce the energy consumption of the node and prolong the network life cycle.

DS/SS 이동 통신에서 반복적 최소 자승 역전파 신경망을 이용한 적응 상관기 (Performance of Adaptive Correlator using Recursive Least Square Backpropagation Neural Network in DS/SS Mobile Communication Systems)

  • 정우열;김환용
    • 한국음향학회지
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    • 제15권2호
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    • pp.79-84
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    • 1996
  • 본 논문은 CDMA 이동 통신 시스템에서 직접 순차 확산 스펙트럼의 협대역 간섭 신호를 억압하기 위해 다계층 퍼셉트론을 기본으로 한 역전파 신경망을 이용하여 적응 상관기 모델을 제시하였다. 적응 상관기 구조는 빠른 수렴 율과 보다 좋은 성능을 제공하기 위해 역전파된 에러를 가진 반복적 최소 자승 역전파 알고리즘을 도입하였다. 컴퓨터 시뮬레이션 결과는 동일 채널 간섭과 협대역 간섭을 고려한 신호 잡음비와 전송 전력비에 대해 직접 순차 확산 스펙트럼 적응 횡단선 필터의 비트 에러율보다 역전파 신경망을 이용한 적응 상관기의 비트 에러율이 개선됨을 보였고, 특히 간섭 대 신호비가 5dB인 곳에서 역전파 신경망을 이용한 적응 상관기가 적응 횡단선 필터의 비트 에러율보다 약 $10^{-1}$ 정도 감소되었다.

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