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91.
对中国乒乓球队优秀女子左手横板运动员的技战术分析 总被引：1，自引：0，他引：1
对我国优秀乒乓球运动员王楠和郭跃在各大比赛中的技战术运用情况进行分析,旨在为中国乒乓球运动员在今后的训练中提供参考依据。 相似文献
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93.
《Journal of The Franklin Institute》2022,359(12):6503-6522
This paper focuses on the dynamic event-based recursive filtering problem for a class of time-varying networked systems under the encoding-decoding mechanism. For the purpose of saving energy consumption, a dynamic event-triggered protocol is applied to determine whether the measurement of the sensor is transmitted or not. In the transmission process of the measurement, a dynamic-quantization-based encoding-decoding mechanism is introduced to encrypt the transmitted measurement. In specific, the measurement outputs are first encoded into codewords which are then transmitted from the encoder to the decoder. After received by the decoder, the codewords are first decoded and then sent to the filter. A bounded uncertainty is introduced to characterize the difference between the original measurement and the decoded measurement. This paper is devoted to developing a recursive filtering algorithm for the considered system such that a minimal upper bound on the filtering error covariance is derived through appropriately designing filter gain. Moreover, the mean-square exponential boundedness of the filtering error is analyzed. Finally, the efficiency and superiority of the proposed algorithm are verified through two simulation examples. 相似文献
94.
《Journal of The Franklin Institute》2022,359(14):7438-7457
This article investigates the adaptive regulation problem of uncertain delayed nonlinear systems. Remarkably, the systems have multiple delays in systems’ states and the input, and the nonlinear terms as a whole can belong to one of four different growing conditions. By introducing the dynamic-gain-based transformations, we obtain the new dynamic systems. By using homogeneous domination method, adaptive regulation strategy and by flexibly selecting the dynamic gain, two unified adaptive control methods are presented such that the obtained systems are globally asymptotic stable. Simulation results verify the effectiveness of the methods of this paper. 相似文献
95.
《Journal of The Franklin Institute》2022,359(12):6336-6360
In this paper, for multiple Euler–Lagrange systems embodying external disturbances and unknown uncertainties, the problems of collision-avoiding formation (CAF) are investigated. With regard to Euler–Lagrange systems under healthy actuator condition and under actuator failures, two distributed collision-avoiding formation (DCAF) control laws are proposed. In one case, which the systems are under healthy actuator condition, firstly, a robust continuous term with adaptive variable gain is utilized to reduce the influence of external disturbances under unknown range. In addition, in order to handle the uncertainties of dynamical systems and collision avoidance, both the estimations for uncertain terms and repulsive potential functions are established in design of algorithms. For the other case, the systems under actuator failures, by utilizing the Lyapunov function and relevant adaptive updating laws, the effects subjected to partial loss of actuator effectiveness can be eliminated. Eventually, two distributed algorithms are proposed to achieve the expected formation configuration with no collision occurred. Numerical simulations are conducted to illustrate the validities of the presented control methodologies. 相似文献
96.
Wentao Bai Fan Guo Lei Chen Kuangrong Hao Biao Huang 《Journal of The Franklin Institute》2021,358(8):4546-4570
In traditional system identification methods, it is often assumed that the output data are corrupted by Gaussian white noise which is independent and identically distributed (i.i.d.). However, this assumption may lead to poor robustness since the noise characteristic often varies throughout the sampling process. In this work, output measurements affected by switching Gaussian noise are considered. In addition, a Markov chain model is utilized to describe the multi-mode behavior of the noises. Meanwhile, the collected data are usually incomplete in practice. Taking these circumstances into account, a new algorithm for Gaussian process regression (GPR) with switching noise mode and missing data is introduced. The parameters of the model are estimated by expectation maximization (EM) algorithm via conjugate gradient (CG) method. Two numerical examples along with a continuous stirred tank reactor simulation are employed to verify the effectiveness of the proposed algorithm. The superior performance is demonstrated by comparing the proposed algorithm with other existing relevant methods. 相似文献
97.
《Journal of The Franklin Institute》2021,358(17):9135-9157
The probabilistic-constrained tracking control issue is investigated for a class of time-varying nonlinear stochastic systems with sensor saturation, deception attacks and limited bandwidth in an unified framework. The saturation of sensors is quantified by a sector-bound-based function satisfying certain conditions, and the random deception attacks are considered and modeled by a random indicator variable. To gain more efficient utilization of communication channels, a Round-Robin (RR) protocol is utilized to orchestrate the transmission order of measurements. The main purposes of this study aim to plan an observer-based tracking controller to achieve the following goals: (1) the related performance indicators of the estimation error is less than given bound at each time step; and (2) the violation probability of the tracking error confined in a predefined scope is supposed to be higher than a prescribed scalar and the area is minimized at each instant. In order to reach these requirements, a group of recursive linear matrix inequalities (RLMIs) are developed to estimate the state and design the tracking controller at the same time. Finally, two simulation examples are exploited to illustrate the availability and flexibility of the proposed scheme. 相似文献
98.
2004年以后,大学校园体育文化研究与建设成为中国大学体育的重要内容之一。文章在调查分析当前中国大学校园体育文化建设存在的问题与不足,探究学生的感受基础上,认为中国大学校园体育文化发展中的问题归因于传统教育文化、高等教育体制和社会变革引起的文化多元化。要改变现状,需要从学校、国家层面改变体育文化观念,制定政策并建立评估体系,加强大学生文化内涵探究和中外校园体育文化的比较研究。 相似文献
99.
黑龙江省普通高校乒乓球选修课开展现状及对策研究 总被引：1，自引：0，他引：1
殷晓丽 《哈尔滨体育学院学报》2010,(6):84-85
采用文献资料法、专家访谈法、调查问卷法、数理统计法对黑龙江省部分高校的乒乓球选修课开展情况进行了调查和研究。通过研究提出了改善乒乓球选修课开展现状的对策和建议，以期为乒乓球选修课教学提供参考。 相似文献
100.
贾智丰 《哈尔滨体育学院学报》2010,28(1):87-89
近几年,随着我国足球职业化改革的不断深入,培养足球后备人才的中坚力量——少年足球也在不断的发展。但时至今日各足球俱乐部、学校的足球教练员的训练能力和水平参差不齐。此文采用文献资料、访问调查、问卷调查等研究方法对大连市的足球教练员的现状和能力水平进行研究,通过研究提出了提高教练员水平的的建议和对策。 相似文献