• Title/Summary/Keyword: Complex adaptive system

Search Result 253, Processing Time 0.026 seconds

PCA-based neuro-fuzzy model for system identification of smart structures

  • Mohammadzadeh, Soroush;Kim, Yeesock;Ahn, Jaehun
    • Smart Structures and Systems
    • /
    • v.15 no.4
    • /
    • pp.1139-1158
    • /
    • 2015
  • This paper proposes an efficient system identification method for modeling nonlinear behavior of civil structures. This method is developed by integrating three different methodologies: principal component analysis (PCA), artificial neural networks, and fuzzy logic theory, hence named PANFIS (PCA-based adaptive neuro-fuzzy inference system). To evaluate this model, a 3-story building equipped with a magnetorheological (MR) damper subjected to a variety of earthquakes is investigated. To train the input-output function of the PANFIS model, an artificial earthquake is generated that contains a variety of characteristics of recorded earthquakes. The trained model is also validated using the1940 El-Centro, Kobe, Northridge, and Hachinohe earthquakes. The adaptive neuro-fuzzy inference system (ANFIS) is used as a baseline. It is demonstrated from the training and validation processes that the proposed PANFIS model is effective in modeling complex behavior of the smart building. It is also shown that the proposed PANFIS produces similar performance with the benchmark ANFIS model with significant reduction of computational loads.

Development of an Adaptive Neuro-Fuzzy Techniques based PD-Model for the Insulation Condition Monitoring and Diagnosis

  • Kim, Y.J.;Lim, J.S.;Park, D.H.;Cho, K.B.
    • Electrical & Electronic Materials
    • /
    • v.11 no.11
    • /
    • pp.1-8
    • /
    • 1998
  • This paper presents an arificial neuro-fuzzy technique based prtial discharge (PD) pattern classifier to power system application. This may require a complicated analysis method employ -ing an experts system due to very complex progressing discharge form under exter-nal stress. After referring briefly to the developments of artificical neural network based PD measurements, the paper outlines how the introduction of new emerging technology has resulted in the design of a number of PD diagnostic systems for practical applicaton of residual lifetime prediction. The appropriate PD data base structure and selection of learning data size of PD pattern based on fractal dimentsional and 3-D PD-normalization, extraction of relevant characteristic fea-ture of PD recognition are discussed. Some practical aspects encountered with unknown stress in the neuro-fuzzy techniques based real time PD recognition are also addressed.

  • PDF

The Emerging Role of Natural Killer Cells in Innate and Adaptive Immunity

  • Kim, Eun-Mi;Ko, Chang-Bo;Myung, Pyung-Keun;Cho, Daeho;Choi, Inpyo;Kang, Hyung-Sik
    • IMMUNE NETWORK
    • /
    • v.4 no.4
    • /
    • pp.205-215
    • /
    • 2004
  • In the early host defense system, effector function of natural killer (NK) cells results in natural killing against target cells such as microbe-infected, malignant, and certain allogenic cells without prior stimulation. NK cell cytotoxicity is selectively regulated by homeostatic prevalence between a repertoire of both activating and inhibitory receptors, and the discrimination of untransformed cells is achieved by recognition of major histocompatibility complex (MHC) class I alleles through inhibitory signals. Although it is well known that the bipotential T/NK progenitors are derived from the common precusor, functional mechanisms in terms of the development of NK cells remain to be further investigated. NK cells are mainly involved in innate immunity, but recent studies have been reported that they also play a critical role in adaptive immune responses through interaction with dendritic cells (DC). This interaction will provide effector functions and development of NK cells, and elucidation of its precise mechanism may lead to therapeutic strategies for effective treatment of several immune diseases.

Complex Process Control using the Adaptive Neural Fuzzy Inference System

  • Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.351-351
    • /
    • 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.

  • PDF

A Study of Adaptive Load Torque Observer and Robust Precision Position Control of BLDD Motor (직접 구동용 BLDC 전동기의 정밀 Robust 위치제어 및 적응형 외란 관측기 연구)

  • 고종선;윤성구
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.4 no.2
    • /
    • pp.138-143
    • /
    • 1999
  • A new control method for the precision robust position control of a brushless DC(BLDC) motor for direct drive m motor(BLDDM) system using the asymptotically stable adaptive load torque observer is presented. A precision position c control is obtained for the BLDD motor system appro성mately linearized using the fieldlongrightarroworientation method. Many of t these motor systems have BLDD motor to obtain no backlashes. On the other hand, it has disadvantages such as the h high cost and more complex controller caused by the nonlinear characteristics. And the load torque disturbance is d directly affected to a motor shaft. To r밍ect this problem, stability analysis is calTied out using Lyapunov stability t theorem. Using this results, the stability is proved and load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent CUlTent having the fast response.

  • PDF

Stabilization Control of Nonlinear System Using Adaptive Neuro-Fuzzy Controller (적응 뉴로-퍼지 제어기를 이용한 비선형 시스템의 안정화 제어)

  • Lee, In-Yong;Tack, Han-Ho;Lee, Sang-Bae;Park, Boo-Gue
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.5 no.4
    • /
    • pp.730-737
    • /
    • 2001
  • In this paper, an stabilization control method using adaptive neuro-fuzzy controller(ANFC) is proposed for modeling of nonlinear complex systems. The proposed adaptive neuro-fuzzy controller implements system structure and parameter identification using the intelligent schemes together with optimization theory, linguistic fuzzy implication rules, and neural networks from input and output data of processes. The results show that the proposed method can produce the intelligence model with higher accuracy than other works achieved previously.

  • PDF

The Framework for Adaptive ERP Systems Using the Ontology Model of a Manufacturing Supply Chain (제조업 공급망 온톨로지 기반 적응형 ERP 모듈 시스템 프레임워크)

  • Oh, Yeonggwang;Han, Hweeyoung;Shin, Dongmin;Kim, Dongchul;Kim, Namhun
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.41 no.4
    • /
    • pp.344-351
    • /
    • 2015
  • Recently, an ERP (Enterprise resource Planning) system has been becoming an essential S/W tool for companies to manage their business processes and manufacturing resources. As the information exchange becomes more complex, not only corporate companies but also small- and mid- sized enterprises (SMEs) are required to build an ERP system. However, for small- and middle- sized companies, the adoption of ERP systems becomes challenging due to high cost and long installation time of the system. This paper presents a novel concept of an adaptive ERP system incorporating the ontology structure of the business supply chain information. The proposed ERP installation methodology is illustrated with an example of a door-trim manufacturing company in the automotive supply chain.

Development of Neural Network Controller for Maximum Power Point Tracking of PV System (PV 시스템의 최대전력점 추적을 위한 신경회로망 제어기 개발)

  • Ko, Jae-Sub;Choi, Jung-Sik;Jung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.1
    • /
    • pp.41-48
    • /
    • 2009
  • This paper presents an Neural Network(NN) controller for Maximum Power Point Tracking (MPPT) of PV supplied DC motor. A variation of solar irradiation is most important factor in the MPPT of PV system. That is nonlinear, aperiodic and complicated. NN was widely used due to easily solving a complex math problem. Proposed photovoltaic system consists of NN, DC-DC converter, DC motor and load(cf, pump). NN algorithm apply to DC-DC converter through an Adaptive control of Neural Network, calculates Converter-Chopping ratio using an Adaptive control of NN. The results of an Adaptive control of NN compared with the results of Converter-Chopping ratio which are calculated mathematical modeling and evaluate the proposed algorithm. The experimental data show that an adequacy of the algorithm was established through the compared data.

A many-objective optimization WSN energy balance model

  • Wu, Di;Geng, Shaojin;Cai, Xingjuan;Zhang, Guoyou;Xue, Fei
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.14 no.2
    • /
    • pp.514-537
    • /
    • 2020
  • Wireless sensor network (WSN) is a distributed network composed of many sensory nodes. It is precisely due to the clustering unevenness and cluster head election randomness that the energy consumption of WSN is excessive. Therefore, a many-objective optimization WSN energy balance model is proposed for the first time in the clustering stage of LEACH protocol. The four objective is considered that the cluster distance, the sink node distance, the overall energy consumption of the network and the network energy consumption balance to select the cluster head, which to better balance the energy consumption of the WSN network and extend the network lifetime. A many-objective optimization algorithm to optimize the model (LEACH-ABF) is designed, which combines adaptive balanced function strategy with penalty-based boundary selection intersection strategy to optimize the clustering method of LEACH. The experimental results show that LEACH-ABF can balance network energy consumption effectively and extend the network lifetime when compared with other algorithms.

Performance Analysis of Co-Existence of DS-CDMA and TDMA System by Using Complex Multirate Filter Bank in Land Mobile Channel (육상 이동통신 채널에서 복소 다중비율 필터뱅크를 채용한 DS-CDMA/TDMA 공존 시스템의 성능 분석)

  • 우병훈;강희조
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.11 no.1
    • /
    • pp.1-7
    • /
    • 2000
  • In this paper, we proposed a complex multirate filter bank(CMRFB) based adaptive notch filtering technique to solve the co-existence narrowband interference problem of DS-CDMA and TDMA systems. We have discussed error performance of co-existence of DS-CDMA and TDMA system by using complex multirate filter bank in land mobile channel and computer simulation results show that the proposed scheme can eliminate the narrowband interference(TDMA signals) effectively.

  • PDF