2019年篮联世界杯广州赛区小组赛对中国队的启示     

崔曼峰  赵毅砥 《广州体育学院学报》2020,(1):82-85

2019年国际篮联篮球世界杯在中国圆满举行,广州作为分赛场,承接了西班牙、波多黎各、突尼斯以及伊朗四支代表队的小组比赛6场。通过对广州赛区四支队伍在小组赛中的表现技术进行分析,并对比中国队在本次赛事中的表现,发现中国男篮在备赛与参赛阶段,存在大赛目标不清晰,心理训练与细节训练不足,教练团队执教水平不稳定,篮球基本功不扎实等一系列问题,反映出我国篮球的发展正处于困境。系统地分析广州小组赛中四支队伍的赛况,并与中国队做出对比,有针对性地提出建议,为中国篮球的发展提供参考。  相似文献   

我国大学生高水平排球队空间分布特征及影响因素研究*     

马茂森    李毅钧  张〓兵  杨玲 《广州体育学院学报》2020,(5):78-84

利用核密度分析、巴雷托截取法和多元回归分析等方法，对我国大学生高水平排球队空间分布特征和影响因素进行分析。主要结论有：大学生高水平排球队的数量呈波动上升趋势；在规模结构上，大学生高水平排球队数量规模的省际分布呈现倒“金字塔”结构，而配比规模的省际分布呈现“金字塔”结构，且极不平衡；在空间格局上，具有显著的区域差异，表现出东部区域较多；在集聚特征上，大学生高水平排球队主要分布在直辖市和省会城市，主要集聚在京津翼地区和长江流域，其他地区比较分散；在空间竞技实力上，具有显著的区域不平衡性，呈现“南弱北强”的特征；影响大学生高水平排球队空间分布的主要因素有高校招生条件、本科院校数量、经济发展实力和体育发展水平。  相似文献   

Optimal synchronization controller design for complex dynamical networks with unknown system dynamics     

Ya-Wei Cao  Guang-Hong Yang  Xiao-Jian Li 《Journal of The Franklin Institute》2019,356(12):6071-6086

In this paper, the optimal synchronization controller design problem for complex dynamical networks with unknown system internal dynamics is studied. A necessary and sufficient condition on the existence of the optimal control minimizing a quadratic performance index is given. The optimal control law consists of a feedback control and a compensated feedforward control, and the feedback control gain can be obtained by solving the well-known Algebraic Riccati Equation (ARE). Especially, in the presence of unknown system dynamics, a novel adaptive iterative algorithm using the information of system states and inputs is proposed to solve the ARE to get the optimal feedback control gain. Finally, a simulation example shows the effectiveness of the theoretical results.  相似文献   

Intermittent control strategy for synchronization of fractional-order neural networks via piecewise Lyapunov function method     

Ying Yang  Yong He  Min Wu 《Journal of The Franklin Institute》2019,356(8):4648-4676

In this paper, the synchronization problem of fractional-order neural networks (FNNs) with chaotic dynamics is investigated via the intermittent control strategy. Two types of intermittent control methods, the aperiodic one and the periodic one, are applied to achieve the synchronization of the considered systems. Based on the dynamic characteristics of the intermittent control systems, the piecewise Lyapunov function method is employed to derive the synchronization criteria with less conservatism. The results under the aperiodically intermittent control show more generality than the ones via the periodically intermittent control. For each of the aperiodic and periodic cases, a simple controller design process is presented to show how to design the corresponding intermittent controller. Finally, two numerical examples are provided to demonstrate the effectiveness of the obtained theoretical results.  相似文献   

Super-twisting observer-based sliding mode control with fuzzy variable gains and its applications to fully-actuated hexarotors     

Ngo Phong Nguyen  Wonhee Kim  Jun Moon 《Journal of The Franklin Institute》2019,356(8):4270-4303

In this paper, we consider the super-twisting observer-based sliding mode control algorithm with fuzzy variable gains (STOSMC) for the fully-actuated hexarotor. Our hexarotor has full actuation due to six titled propellers that allows to control position and orientation (attitude) simultaneously, and resolves the singularity problem of the rotational matrix by using the quaternion modeling framework. We show that the proposed STOSMC for the hexarotor guarantees finite-time convergence of the estimation error and asymptotic stability of the hexarotor. In simulations, we demonstrate the nonsingularity and fully-actuated control performance of the hexarotor by considering extreme position and attitude control scenarios. Moreover, the simulation results show that the hexarotor achieves the fast and precise tracking performance to the desired position and the desired attitude and the chattering phenomenon is reduced compared with the fixed-gains observer-based super-twisting sliding mode control due to the fuzzy mechanism.  相似文献   

Organizational justice and management trustworthiness during organizational Change: Interactions of Benevolence,Integrity, and managerial approaches     

Yu Cui  Hao Jiao 《Information processing & management》2019,56(4):1526-1542

Trust and justice play an important role in the process of organizational change to build dynamic capabilities for sustainable competitive advantage. This study investigated the interaction effects of management's benevolence trustworthiness and integrity trustworthiness on employees’ perception of procedural justice during innovation or organizational change. Both the scenario and the field study showed that the patterns of the interaction effects of these two components of trustworthiness are further influenced in a complementary manner by different innovation approaches. The study indicated that the relationships between benevolence trustworthiness and integrity trustworthiness are far more complex than expected and thus need more research efforts.  相似文献   

Moment matching model reduction for negative imaginary systems     

Lanlin Yu  Junlin Xiong 《Journal of The Franklin Institute》2019,356(4):2274-2293

In this paper, moment matching model reduction problem for negative imaginary systems is considered. For a given negative imaginary system with poles at the origin, our goal is to find a reduced-order negative imaginary system such that a prescribed number of the moments and the poles at the origin are preserved. Firstly, the original negative imaginary system is split into an asymptotically stable subsystem, a lossless negative imaginary subsystem and an average subsystem. Then, moment matching model reduction is implemented on the asymptotically stable subsystem and the lossless negative imaginary subsystem. The resulting reduced-order system preserves the negative imaginary structure and the poles at the origin. Also, the proposed model reduction method is extended to the positive real systems. Numerical examples demonstrate the effectiveness of the proposed model reduction method.  相似文献   

Linear output-feedback-based semi-global stabilization for switched nonlinear time-delay systems     

Zhenhua Li  Lijun Long  Jun Zhao 《Journal of The Franklin Institute》2019,356(13):7224-7245

This paper focuses on the problem of semi-global output-feedback stabilization for a class of switched nonlinear time-delay systems in strict-feedback form. A switched state observer is first constructed, then switched linear output-feedback controllers for individual subsystems are designed. By skillfully constructing multiple Lyapunov–Krasovskii functionals and successfully solving several troublesome obstacles, such as time-varying delay and switching signals and nonlinearity in the design procedure, the switched linear output-feedback controllers designed can render the resulting closed-loop switched system semi-globally stabilizable under a class of switching signals with average dwell time. Furthermore, under some milder conditions on nonlinearities, the semi-global output-feedback stabilization problem for switched nonlinear time-delay systems is also studied. Simulation studies on two examples, which include a continuous stirred tank reactor, are carried out to demonstrate the effectiveness of the proposed approach.  相似文献   

Multi-lagged-input iterative dynamic linearization based data-driven adaptive iterative learning control     

Na Lin  Ronghu Chi  Biao Huang  Zhongsheng Hou 《Journal of The Franklin Institute》2019,356(1):457-473

This article presents a multi-lagged-input based data-driven adaptive iterative learning control (M-DDAILC) method for nonlinear multiple-input-multiple-output (MIMO) systems by virtue of multi-lagged-input iterative dynamic linearization (IDL). The original nonlinear and non-affine MIMO system is equivalently transformed into a linear input-output incremental counterpart without loss of dynamics. The proposed learning law utilizes the desired trajectory to cancel the influence from iteration-by-iteration variations, as well as additional multi-lagged inputs to improve control performance. The developed iterative estimation law is more effective and also makes estimation of the unknown parameters easier because the dynamics for each parameter to represent are decreased by dividing the system into multiple components in the multi-lagged-input IDL formulation. Moreover, the proposed M-DDAILC does not need an explicit and accurate model. It is proved to be iteratively convergent with rigorous analysis. Both a numerical example and a practical application to a permanent magnet linear motor are provided to verify the validity and applicability of the proposed method.  相似文献   

Dynamics of a stochastic multigroup SIQR epidemic model with standard incidence rates     

Qun Liu  Daqing Jiang  Tasawar Hayat  Ahmed Alsaedi 《Journal of The Franklin Institute》2019,356(5):2960-2993

In this paper, we consider a stochastic multigroup SIQR epidemic model with standard incidence rates. By using the stochastic Lyapunov function method, we establish sufficient conditions for the existence of a stationary distribution of the positive solutions to the model. Then we establish sufficient conditions for extinction of the diseases. A stationary distribution means that all the individuals can be coexistent and persistent in the long term. Finally, some examples and numerical simulations are introduced to illustrate our theoretical results.  相似文献