基于协调论的矿区可持续发展研究

将矿区视为由资源、环境、安全、经济与社会所构成的复杂非线性系统,讨论其特征,以协调论为基础,建立矿区协调熵度量模型,以某典型矿区为例进行实证分析,进一步提出矿区的可持续发展对策。     

基于位置伺服系统的速度环滑模变结构控制器研究

本文应用状态反馈线性化方法对电枢反应非线性进行线性化处理,通过适当的非线性状态变换和输入变换,将速度非线性控制系统综合问题转化为线性系统的综合问题,并采用对系统参数变化及外界扰动具有较强鲁棒性的滑模变结构控制方法,实现了直流电机速度的跟踪控制。     

非线性兴波数值方法在三体船球首设计中的应用

为减小三体船阻力,在三体船中体上加球首,采用考虑升沉和纵倾影响的三体船非线性兴波阻力及航行姿态预报数值方法,对加装设计球首的2种典型侧体布局三体船阻力进行理论计算,并开展模型试验研究;表明非线性兴波阻力数值方法能够较好地反映三体船兴波阻力特性,加球首可有效减少三体船中高航速的兴波阻力。     

表面肌电信号分析评价肌肉疲劳的有效性和敏感性

目的:测定和分析应用表面肌电信号分析指标评价肌肉疲劳的有效性和敏感性,方法:选取健康无专业运动男、女大学生各10名,进行3个膝关节角度(90°、60°和30°)×3个运动负荷(40％MVC、60％MVC和80％ MVC)共9次静力性等长疲劳实验,同步记录sEMG信号并进行线性和非线性信号处理.结果:sEMG信号分析指标表现出单调性变化,且采样序列线性拟合具有显著性.膝关节角度、运动负荷和性别对各指标的变化率有显著影响.结论:应用非线性分析指标评价肌肉疲劳具有很好的敏感性.     

重剑运动员弓步刺动作协调性的非线性动力学特征

采用视频动作解析法,研究重剑运动员在不同速度、不同情境下弓步刺动作肘膝关节角度变化的运动学特征.结果显示:不同速度要求下,重剑运动员弓步刺动作协调性存在非线性动力学特征;不同情境下,重剑运动员弓步刺动作协调性可能存在非线性动力学特征;高、低水平重剑运动员在平时训练时的弓步刺动作协调模式相似;比赛情境时,高水平重剑运动员的弓步刺动作协调性显著好于低水平重剑运动员.     

Direction-Based Adaptive Switching Filter for Removing High-Density Impulse Noise

A direction-based adaptive switching(DBAS) filter is presented for the removal of high-density impulse noise in images. The extrema detection and 28-directional detection are employed to discriminate the pixels as noisy or noise-free. If a pixel is classified as noisy, it will be replaced by a median or a mean value within an adaptive filter window with respect to different noise densities. Simulation results show that the miss-detection ratio and false-alarm ratio are both very low even at noise level as high as 90%. At the same time, better results are obtained in terms of the qualitative and quantitative measures. The peak signal-to-noise ratios increase by nearly 1 dB compared with other existing algorithms. In addition, the computation time is around 10 s for test images with resolutions of 512×512since the proposed approach has low complexity.     

Robust Adaptive Control Design for Rotorcraft Unmanned Aerial Vehicles Based on Sliding Mode Approach

This paper presents a nonlinear robust control design method for a generic rotorcraft unmanned aerial vehicle（RUAV）. The control objective is to let the RUAV track some pre-defined time-varying position and headingtrajectories. The proposed controller employs feedback linearization process to realize the dynamic decoupling controland applies adaptive sliding mode control to compensate for the parametric uncertainties and external disturbances.The global asymptotical stability is proved via stability analysis. Compared with the cascaded controller, the proposedcontroller demonstrates a superior tracking performance and robustness through numerical simulation in the presenceof parametric uncertainties and unknown disturbances.     

一类高阶非线性微分方程周期解的存在性

运用Mawhin连续性定理,研究一类高阶非线性微分方程(φp(x(t)-cx(t-r)(m)(m))+∑i=1mfi(x)(i-1)(t x(i)(t)+g(t,x(t))=e(t),获得了其周期解存在性新的充分条件.     

一个解非线性互补问题的非精确 Jacobian 光滑化方法

基于光滑互补函数,将非线性互补问题等价转化光滑方程组问题,构造了一个新的求解该光滑方程组的非精确 Jacobian 光滑化方法,该算法克服牛顿法解大规模互补问题的不便,并证明了该算法具有全局收敛性,在一定的假设条件下具有局部二次收敛性。     

一类非线性三阶两点边值问题的三重正解

根据非线性项函数的增长与相应积分方程的特性构造了高度函数,利用高度函数的积分给出了一类非线性三阶两点边值问题解的先验界及三个正解的存在性。