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  • Open Access

    ARTICLE

    Model Predictive Control for High-speed Train with Automatic Trajectory Configuration and Tractive Force Optimization

    Yonghua Zhou1 , Xun Yang1 , Chao Mi1

    CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.6, pp. 415-437, 2013, DOI:10.3970/cmes.2013.090.415

    Abstract High-speed train transportation is organized in a way of globally centralized planning and locally autonomous adjustment with the real-time known positions, speeds and other state information of trains. The hierarchical integration architecture composed of top, middle and bottom levels is proposed based on model predictive control (MPC) for the real-time scheduling and control. The middle-level trajectory configuration and tractive force setpoints play a critical role in fulfilling the top-level scheduling commands and guaranteeing the controllability of bottomlevel train operations. In the middle-level MPC-based train operation planning, the continuous cellular automaton model of train movements is proposed to dynamically configure the… More >

  • Open Access

    ARTICLE

    Numerical solution of nonlinear fractional integral differential equations by using the second kind Chebyshev wavelets

    Yiming Chen1, Lu Sun1, Xuan Li1, Xiaohong Fu1

    CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.5, pp. 359-378, 2013, DOI:10.3970/cmes.2013.090.359

    Abstract By using the differential operator matrix and the product operation matrix of the second kind Chebyshev wavelets, a class of nonlinear fractional integral-differential equations is transformed into nonlinear algebraic equations, which makes the solution process and calculation more simple. At the same time, the maximum absolute error is obtained through error analysis. It also can be used under the condition that no exact solution exists. Numerical examples verify the validity of the proposed method. More >

  • Open Access

    ARTICLE

    Numerical Solution of Space-Time Fractional Convection-Diffusion Equations with Variable Coefficients Using Haar Wavelets

    Jinxia Wei1, Yiming Chen1, Baofeng Li2, Mingxu Yi1

    CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.6, pp. 481-495, 2012, DOI:10.3970/cmes.2012.089.481

    Abstract In this paper, we present a computational method for solving a class of space-time fractional convection-diffusion equations with variable coefficients which is based on the Haar wavelets operational matrix of fractional order differentiation. Haar wavelets method is used because its computation is sample as it converts the original problem into Sylvester equation. Error analysis is given that shows efficiency of the method. Finally, a numerical example shows the implementation and accuracy of the approach. More >

  • Open Access

    ARTICLE

    Haar Wavelet Operational Matrix Method for Solving Fractional Partial Differential Equations

    Mingxu Yi1, Yiming Chen1

    CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.3, pp. 229-244, 2012, DOI:10.3970/cmes.2012.088.229

    Abstract In this paper, Haar wavelet operational matrix method is proposed to solve a class of fractional partial differential equations. We derive the Haar wavelet operational matrix of fractional order integration. Meanwhile, the Haar wavelet operational matrix of fractional order differentiation is obtained. The operational matrix of fractional order differentiation is utilized to reduce the initial equation to a Sylvester equation. Some numerical examples are included to demonstrate the validity and applicability of the approach. More >

  • Open Access

    ARTICLE

    A Compensation Controller Based on a Nonlinear Wavelet Neural Network for Continuous Material Processing Operations

    Chen Shen1,*, Youping Chen1, Bing Chen1, Jingming Xie1

    CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 379-397, 2019, DOI:10.32604/cmc.2019.04883

    Abstract Continuous material processing operations like printing and textiles manufacturing are conducted under highly variable conditions due to changes in the environment and/or in the materials being processed. As such, the processing parameters require robust real-time adjustment appropriate to the conditions of a nonlinear system. This paper addresses this issue by presenting a hybrid feedforward-feedback nonlinear model predictive controller for continuous material processing operations. The adaptive feedback control strategy of the controller augments the standard feedforward control to ensure improved robustness and compensation for environmental disturbances and/or parameter uncertainties. Thus, the controller can reduce the need for manual adjustments. The controller… More >

  • Open Access

    ARTICLE

    Bus Priority Control for Dynamic Exclusive Bus Lane

    Zhibo Gao1,2, Kejun Long1,2,*, Chaoqun Li2, Wei Wu1,2, Lee. D. Han3

    CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 345-361, 2019, DOI:10.32604/cmc.2019.06235

    Abstract One problem with the existing dynamic exclusive bus lane strategies is that bus signal priority strategies with multi-phase priority request at intersections are not adequately considered. The principle of bus signal priority level was designed based on the isolated multi-phase structure principle consideration of the bus signal priority, and a new priority approach for the dynamic exclusive bus lane was proposed. Two types of priority strategies, green extension and red truncation, were proposed for current phase and next phase buses, respectively. The control parameters including minimum green time, green extension time, maximum green time and bus arrival time are calculated.… More >

  • Open Access

    ARTICLE

    Analysis and Improvement of an Efficient Controlled Quantum Secure Direct Communication and Authentication Protocol

    Jifeng Zhong1,*, Zhihao Liu2,3,*, Juan Xu4

    CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 621-633, 2018, DOI:10.32604/cmc.2018.03706

    Abstract The controlled quantum secure direct communication (CQSDC) with authentication protocol based on four particle cluster states via quantum one-time pad and local unitary operations is cryptanalyzed. It is found that there are some serious security issues in this protocol. An eavesdropper (Eve) can eavesdrop on some information of the identity strings of the receiver and the controller without being detected by the selective-CNOT-operation (SCNO) attack. By the same attack, Eve can also steal some information of the secret message that the sender transmits. In addition, the receiver can take the same kind of attack to eavesdrop on some information of… More >

  • Open Access

    ARTICLE

    Research on Operation of UAVs in Non-isolated Airspace

    Zhaoyue Zhang1, *, Jing Zhang2, Peng Wang1, Lei Chen3

    CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 151-166, 2018, DOI:10.32604/cmc.2018.02890

    Abstract In order to explore the safe operation of UAVs in non-segregated airspace, a collision risk model for cylindrical UAVs based on conflict areas was constructed and the risk of conflict between manned and unmanned aerial vehicles was researched. According to the results of risk analysis, a strategy for solving the conflict of aircraft is proposed, and the risk assessment experiment of unmanned aerial vehicle (UAV) in non-isolated airspace conflict is carried out. The results show that under the experimental conditions, large unmanned aerial vehicles equipped with ADS-B, TCAS and other airborne sensing systems will indeed interfere with other aircraft in… More >

  • Open Access

    ARTICLE

    Research on Trust Model in Container-Based Cloud Service

    Xiaolan Xie1,2, Tianwei Yuan1,*, Xiao Zhou3, Xiaochun Cheng4

    CMC-Computers, Materials & Continua, Vol.56, No.2, pp. 273-283, 2018, DOI: 10.3970/cmc.2018.03587

    Abstract Container virtual technology aims to provide program independence and resource sharing. The container enables flexible cloud service. Compared with traditional virtualization, traditional virtual machines have difficulty in resource and expense requirements. The container technology has the advantages of smaller size, faster migration, lower resource overhead, and higher utilization. Within container-based cloud environment, services can adopt multi-target nodes. This paper reports research results to improve the traditional trust model with consideration of cooperation effects. Cooperation trust means that in a container-based cloud environment, services can be divided into multiple containers for different container nodes. When multiple target nodes work for one… More >

  • Open Access

    ARTICLE

    Improved GNSS Cooperation Positioning Algorithm for Indoor Localization

    Taoyun Zhou1,2, Baowang Lian1, Siqing Yang2,*, Yi Zhang1, Yangyang Liu1,3

    CMC-Computers, Materials & Continua, Vol.56, No.2, pp. 225-245, 2018, DOI: 10.3970/cmc.2018.02671

    Abstract For situations such as indoor and underground parking lots in which satellite signals are obstructed, GNSS cooperative positioning can be used to achieve high-precision positioning with the assistance of cooperative nodes. Here we study the cooperative positioning of two static nodes, node 1 is placed on the roof of the building and the satellite observation is ideal, node 2 is placed on the indoor windowsill where the occlusion situation is more serious, we mainly study how to locate node 2 with the assistance of node 1. Firstly, the two cooperative nodes are located with pseudo-range single point positioning, and the… More >

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