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  • Open Access


    Quality of Service Improvement with Optimal Software-Defined Networking Controller and Control Plane Clustering

    Jehad Ali, Byeong-hee Roh*

    CMC-Computers, Materials & Continua, Vol.67, No.1, pp. 849-875, 2021, DOI:10.32604/cmc.2021.014576

    Abstract The controller is indispensable in software-defined networking (SDN). With several features, controllers monitor the network and respond promptly to dynamic changes. Their performance affects the quality-of-service (QoS) in SDN. Every controller supports a set of features. However, the support of the features may be more prominent in one controller. Moreover, a single controller leads to performance, single-point-of-failure (SPOF), and scalability problems. To overcome this, a controller with an optimum feature set must be available for SDN. Furthermore, a cluster of optimum feature set controllers will overcome an SPOF and improve the QoS in SDN. Herein,… More >

  • Open Access


    SDN Controller Allocation and Assignment Based on Multicriterion Chaotic Salp Swarm Algorithm

    Suresh Krishnamoorthy1,*, Kumaratharan Narayanaswamy2

    Intelligent Automation & Soft Computing, Vol.27, No.1, pp. 89-102, 2021, DOI:10.32604/iasc.2021.013643

    Abstract Increase in demand for multimedia and quality services requires 5G networks to resolve issues such as slicing, allocation, forwarding, and control using techniques such as software-defined networking (SDN) and network function virtualization. In this study, the optimum number of SDN multi-controllers are implemented based on a multi-criterion advanced genetic algorithm that takes into consideration three key parameters: Switch controller latency, hopcount, and link utilization. Preprocessing is the first step, in which delay, delay paths, hopcount, and hoppaths are computed as an information matrix (Infomat). Randomization is the second step, and consists of initially placing controllers… More >

  • Open Access


    Imperfect Premise Matching Controller Design for Interval Type-2 Fuzzy Systems under Network Environments

    Zejian Zhang1, Dawei Wang2,*, Xiao-Zhi Gao3

    Intelligent Automation & Soft Computing, Vol.27, No.1, pp. 173-189, 2021, DOI:10.32604/iasc.2021.012805

    Abstract The interval type-2 fuzzy sets can describe nonlinear plants with uncertain parameters. It exists in nonlinearity. The parameter uncertainties extensively exist in the nonlinear practical Networked Control Systems (NCSs), and it is paramount to investigate the stabilization of the NCSs on account of the section type-2 fuzzy systems. Notice that most of the existing research work is only on account of the convention Parallel Distribution Compensation (PDC). For overcoming the weak point of the PDC and acquire certain guard stability conditions, the state tickling regulator under imperfect premise matching can be constructed to steady the… More >

  • Open Access


    Optimal Robust Control for Unstable Delay System

    Rihem Farkh1,2,*, Khaled A. Aljaloud1, Moufida Ksouri2, Faouzi Bouani2

    Computer Systems Science and Engineering, Vol.36, No.2, pp. 307-321, 2021, DOI:10.32604/csse.2021.014334

    Abstract Proportional-Integral-Derivative control system has been widely used in industrial applications. For uncertain and unstable systems, tuning controller parameters to satisfy the process requirements is very challenging. In general, the whole system’s performance strongly depends on the controller’s efficiency and hence the tuning process plays a key role in the system’s response. This paper presents a robust optimal Proportional-Integral-Derivative controller design methodology for the control of unstable delay system with parametric uncertainty using a combination of Kharitonov theorem and genetic algorithm optimization based approaches. In this study, the Generalized Kharitonov Theorem (GKT) for quasi-polynomials is employed… More >

  • Open Access


    Design of an Observer-Based Controller for T-S Fuzzy Time-Delay Systems under Imperfect Premise Matching

    Zejian Zhang1, Dawei Wang2,*, Peng Li1, Xiao-Zhi Gao3

    Intelligent Automation & Soft Computing, Vol.26, No.5, pp. 905-915, 2020, DOI:10.32604/iasc.2020.010123

    Abstract In this paper, the stabilization problem of an observer-based T-S fuzzy time-delay system under imperfect premise matching is studied, in which the T-S fuzzy observer model with time-delay and the fuzzy controller do not share the same membership functions. The objective is to design a state observer and unmatching fuzzy controller such that the closed-loop system with time-delay is asymptotically stable. A sufficient condition for the stabilization via observerbased state feedback under imperfect premise matching is presented, and an observer-based state feedback controller under imperfect premise is also constructed. The proposed control scheme is well More >

  • Open Access


    A Subsynchronous Oscillation Suppression Method Based on Self-Adaptive Auto Disturbance Rejection Proportional Integral Control of Voltage Source Converter Based Multi-Terminal Direct Current System with Doubly-Fed Induction Generator-Based Wind Farm Access

    Miaohong Su1, Haiying Dong1,2,*, Kaiqi Liu1, Weiwei Zou1

    Energy Engineering, Vol.117, No.6, pp. 439-452, 2020, DOI:10.32604/EE.2020.011805

    Abstract A subsynchronous oscillation suppression strategy based on self-adaptive auto disturbance rejection proportional integral controller is proposed for doublyfed induction generator-based wind farm integrated into grid through voltage source converter based multi-terminal direct current. In this strategy, the nonlinear PI controller is constructed by fal function to replace the traditional linear PI controller, and then the tracking differentiator is used to arrange the appropriate transition process in combination with the idea of active disturbance rejection control, and the self-adaptive auto disturbance rejection proportional integral controller is designed. By applying the controller to the inner loop of the… More >

  • Open Access


    Design of Nonlinear Uncertainty Controller for Grid-Tied Solar Photovoltaic System Using Sliding Mode Control

    D. Menaga1, M. Premkumar2, R. Sowmya1,*, S. Narasimman3

    Energy Engineering, Vol.117, No.6, pp. 481-495, 2020, DOI:10.32604/EE.2020.013282

    Abstract The proposed controller accompanies with different sliding surfaces. To understand maximum power point extraction as opposed to nonlinear uncertainties and unknown disturbance of a grid-connected photovoltaic system to various control inputs (ud, uq) is designed. To extract maximum power from a solar array and maintain unity power flow in a grid by controlling the voltage across the dclink capacitor (Vpvdc) and reactive current (iq). A multiple input-output with multiple uncertainty constraints have considered designing proposed sliding mode controllers to validated their robustness performance. An innovative controller verifies uncertain inputs, constant and changes in irradiances, and temperature of More >

  • Open Access


    Optimization of a Heat Exchanger Using an ARM Core Intelligent Algorithm

    Yajuan Jia, Juanjuan Wang*, Lisha Shang

    FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 871-882, 2020, DOI:10.32604/fdmp.2020.09957

    Abstract In order to optimize heat transfer in a heat exchanger using an ARM (advanced RISC machine) core intelligent computer algorithm, a new type of controller has been designed. The whole control structure of the heat exchange unit has been conceived on the basis of seven functional modules, including data processing and output, human-computer interaction, alarm, and data communication. The main controller and communication controller have been used in a combined fashion and a new MCU (micro control unit) system scheme has been proposed accordingly. A fuzzy controller has been designed by using a fuzzy control More >

  • Open Access


    Systematic Procedure for Optimal Controller Implementation Using Metaheuristic Algorithms

    Viorel Minzu*, Adrian Serbencu

    Intelligent Automation & Soft Computing, Vol.26, No.4, pp. 663-677, 2020, DOI:10.32604/iasc.2020.010101

    Abstract The idea for this work starts from the situation in which a metaheuristic-based algorithm has already been developed in order to solve an optimal control problem. This algorithm yields an offline "optimal" solution. On the other hand, the Receding Horizon Control (RHC) structure can be implemented if a process model is available. This work underlines some of the practical aspects of joining the RHC to an existing metaheuristic-based algorithm in order to obtain a closed-loop control structure that can be further used in real-time control. The result is a systematic procedure that integrates a given More >

  • Open Access


    Practical Application of Fractional Order Controllers to a Delay Thermal System

    Aymen Rhouma1,∗, Sami Hafsi2,†, Faouzi Bouani3

    Computer Systems Science and Engineering, Vol.34, No.5, pp. 305-313, 2019, DOI:10.32604/csse.2019.34.305

    Abstract This paper provides an application of Fractional Model Predictive Control (FMPC) and fractional-order Proportional Integral controller (P Iλ) on a thermal system with time delay.The first controller is based on Grünwald-Letnikov’s method to predict the future dynamic behavior of the system. This method consists in replacing the non-integer derivation operator of the adopted system representation by a discrete approximation. Therefore, this controller is developed on the basis of a fractional order model. However, the second controller is founded on an extended version of Hermite-Biehler theorem to determine the complete set stabilizing P Iλ parameters Experiment results onto More >

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