基于"兴趣-科研-探索"的船舶与海洋工程流体力学启发式教学模式初探

针对船舶与海洋工程流体力学课程的教学特点,提出一种"兴趣–科研–探索"的启发式教学模式。该教学模式以"兴趣驱动"为牵引,以"科研应用"为抓手,以"探索未知"为导向,最大限度地调动学生的主动学习能力和发散思维潜力。以空泡现象为例,将该模式与船舶与海洋工程流体力学知识点相结合,激发学生对于知识点的好奇和兴趣,加深学生对于知识点的掌握和应用,启发学生对于知识点的理解和想象,旨在为该课程教学探索一种新模式。     

控制一类磁性刚体航天器的混沌姿态运动

本文研究一类磁性航天器的混沌姿态运动及其控制,建立了在近地球赤道面圆轨道上运动受万有引力矩、磁力矩作用磁性刚体航天器姿态运动的动力学方程。采用时间历程、Poincare截面、Lyapunov指数和功率谱对系统的动力学行为进行数值识别,结果表明随着磁场参数的增大系统动力学行为由准周期环面破裂而出现混沌。利用输入－输出反馈精确线性化的方法将航天器的混沌姿态控制运动控制为姿态静止和按给定的周期规律运动,数值结果表明该控制方法的有效性。     

英瑞科学家研制成增强激光器效率新方法

~~英瑞科学家研制成增强激光器效率新方法@汪道友~~     

一类带有未知控制方向的非线性系统的适应镇定问题

The adaptive stabilization problem of nonlinear systems are studied. For a class of uncertain nonlinear systems with unknown control direction, we proposed a robust adaptive backstepping scheme withσ-modification by introducing Nussbaum function and Backstep- ping methods, and proved that all the signals of the closed-loop systems are bounded.     

一类非最小相位随机系统的离散自适应滑动模态控制

This paper presents the discrete adaptive sliding mode control of input-output non-minimum phase system in the presence of the stochastic disturbance. The non-minimum phase system can be transformed into a minimum phase system by a operator. According to the minimum phase system, the controller and the adaptive algorithm we designed ensures the stability of system and holds that the mean-square deviation from the sliding surface is minimized.     

Photo-thermal Shot Noise in End Mirrors of LIGO due to Correlation of Power Fluctuation

The effect of input power fluctuation on photo-thermal shot noise in the end mirrors of a laser interferometer gravitational-wave observatory （LIGO） is analysed according to the statistical optics, which is a supplement of Braginsky＇s research. The laser light folding in LIGO increases a correlation of input power fluctuation in the photo-thermal shot noise. This part of noise has spectral density proportional to -2 in low frequency bands, and -4 in high frequency bands. It is not a white noise and may affect the processing about data of interferometers. To obtain an advanced LIGO, photo-thermal shot noise in end mirrors due to correlation of input power fluctuation is up to Braginsky＇s photo-thermal noise in the frequency range 1-100 Hz.     

一种新的支持向量分类方法及其在粮食安全预警系统中的应用

本文提出了支持向量分类的一种新方法，它和标准的支持向量分类方法不同：标准的支持向量分类方法要求每一个输入点（模式）都确切地属于某一类，在本文中我们只要求输入点以某种概率属于某一类。同时，我们把这种方法应用于粮食安全预警问题中。     

老山奥运会自行车馆在多维多点输入下的响应分析和可靠度分析

考虑地震动两个水平分量和一个竖向分量,同时考虑了地震动场的空间相关性,用时程分析法对老山奥运会自行车场馆进行了多维多点输入和多维一致输入下的动力响应分析,考查了两种输入方法下结构响应的差异以及视波速对这种差异的影响.另一方面,本文在快速多点输入反应谱法的基础上,对老山奥运会自行车场馆进行了多维多点输入和多维一致输入下的构件层面上的抗震可靠度分析,考查了两种输入方法下危险杆件在结构分布、数量等方面的差异以及危险杆件随视波速的变化关系.得出以下结论:采用地震动的多点输入法,导致整个结构的内力分布更加均匀;两种输入方法下,杆件内力可靠指标明显降低的杆件有相当一部分位于支承附近区域;会产生一定数量的"一致输入下安全而多点输入下危险"的杆件,且它们大多分布于支承区域附近.     

强地震作用下核电站控制棒下落时间分析

提出了核电站控制棒及驱动系统的力学模型及控制下落时间的计算方法,用显式差分格式计算各构件水平动力反应,并 二维和多点激励,计算结果表明,本文方法的计算结果与实验结果吻合得较好。     

Adaptive synchronization of Chua＇s system with uncertain inputs

The synchronization of Chua's system, whose inputs include an unknown constant parameter, is studied in this paper. A constructive method is applied to designing an adaptive controller, in which only one variable information of the master system is needed. With the action of control signals, the parameter of the slave system will approach the corresponding unknown parameter in the master system. At the same time, the synchronization errors will also converge to zero asymptotically. Numerical simulations show that the proposed theoretical approach is very effective.