二阶非线性微分方程的周期边值问题

本文考虑一个二阶非线性微分方程，它是作为卫星绕着椭圆轨道作周期运动的模型而提出的。我们用初等方法证明了奇周期解的存在性，并且扩大了过去文献中给出的参数范围。     

固相振荡燃烧化学模型系统的混沌控制

对固相振荡燃烧模型所研究的化学现象进行了非线性动力学分析,将线性反馈控制方法应用到化学反应模型中。通过数值仿真,系统的相图、状态历程图、全局分岔图均表明：不断的调整控制参数,该方法能将此系统控制到稳定的周期轨道。     

“专升本”自动化专业运动控制课程教学改革初探

针对"专转本"自动化专业学生特点,结合运动控制课程自身特点及目的,提出了课程内容改革,详细列举了几种教学方法改革,包括:布置开放性课题课程大作业并课堂讨论,采用部分英文PPT讲课,播放专业视频等方法。实践证明,这些教学改革有利于因材施教,培养应用性人才,取得了比较好的教学效果。     

一种高效的分层自动鉴别模糊长度方法

提出了基于图像微分和自相关函数的分层自动鉴别模糊长度方法。通过对水平运动模糊图像或任意角度旋转至水平方向的运动模糊图像先按大小分为不同的层次,再对各层图像计算水平方向的微分,计算水平方向的自相关函数值,得到的结果把各列相加,绘制相应的鉴别曲线,从鉴别曲线中寻找一对最小值的距离用于计算该层次图像的模糊长度估计值,最后选取一组相近的长度估计值求其平均值作为整幅图像的模糊长度。实验表明,自动鉴别方法执行效率更好,精度更高。     

带干扰的双复合Poisson-Geometric风险模型的破产概率

考虑一类推广了的双复合Poisson-Geometric风险模型,假设理赔次数与保费的到达服从Poisson-Geometric分布,且带有Brown运动,运用鞅分析方法和全概率公式分别得出破产概率的表达式.     

Bifurcation of periodic motion of rigid rotor system supported by angular contact ball bearings

Rotor systems supported by angular contact ball bearings are complicated due to nonlinear Hertzian contact force. In this paper, nonlinear bearing forces of ball bearing under five-dimensional loads are given, and 5-DOF dynamic equations of a rigid rotor ball bearing system are established. Continuation-shooting algorithm for periodic solutions of the nonlinear non-autonomous dynamic system and Floquet multipliers of the system are used. Furthermore, the bifurcation and stability of the periodic motion of the system in different parametric domains are also studied. Results show that the bifurcation and stability of period-1 motion vary with structural parameters and operating parameters of the rigid rotor ball bearing system. Avoidance of unbalanced force and bending moment, appropriate initial contact angle, axial load and damping factor help enhance the unstable rotating speed of period-1 motion.     

江苏方言与彝语支位移事件的背景语序轨层

背景语序类型在位移事件研究中未得到足够重视。对语序变化丰富、兼具OV/VO混合特征的江苏等地方言和彝语支等藏缅语的考察,有助于我们更好理解背景的语序类型特征。从本文构建的轨层结构来看,动作发生处所和存在处所居VP层之外,经由、方向、源点、自移终点和致移终点居VP层之内,处在处所、滞留终点和滞留处所可居外亦可居内。     

关于具有摩擦力的园周运动的讨论

本文简单清楚地对具有摩擦力的园周运动的一个特例进行了讨论,并介绍两种应用数字技巧求解速度和克服摩擦力作功的方法,有助于学生们对此概念的理解和掌握。     

匀速运动点电荷电场的一种计算方法

这篇文章用场所在空间的相对论效应给出了匀速运动点电荷的电场强度。     

The influence of a gesture-based learning approach on preschoolers’ learning performance,motor skills,and motion behaviors

This study developed a gesture-based learning approach to build a virtual interactive learning environment for preschoolers by combining a gesture-based computing device and a game-based learning model. Using sequential analysis, this study investigated how this approach influenced children’s learning performance, motor skills, and motion behaviors. A quasi-experiment was conducted with 142 kindergarten-level-3 preschoolers. The results showed that the gesture-based learning approach improved the students’ learning performance and motor skills compared with the traditional activity-based learning approach. The main learning pattern showed that the preschoolers controlled their body motion behaviors and movements to learning cognitive knowledge, which achieving a flow state that improved preschoolers’ learning performance and motor skills. In addition, the main motion pattern showed that the preschoolers interacted with the game by coordinating their body movement with the projected human skeleton’s movement, which improved their motor skills.