关于半正定矩阵Hadamard积的矩阵不等式

半正定矩阵与正定矩阵在不等式的研究上有相当大的区别,将正定矩阵推广至半正定矩阵,需要用Moore Penrose 逆来代替一般的逆.利用分块矩阵和Schur补得到了关于半正定矩阵Moore-Penrose逆的Hadamard积的几个偏序不等式.     

奇异值分解求线性最小二乘解的理论分析

最小二乘问题在数据拟合、参数估计和控制理论等方面有着广泛的作用.本文将利用奇异值分解给出了线性方程Ax=b 的最小二乘解的通解表达式以及广义逆的表达式,并对最小线性二乘问题的条件数进行了论证,指出了当矩阵A 为方阵时怎样估算该方程组的是否是病态的方法.     

反叛?僭越?——明代宗室"谋逆"、"不轨"问题辨析

反叛与僭越是两类不同性质的问题。反叛,是图谋危害皇帝权力及皇帝人身的行为,它是通过策划杀害或废黜在位皇帝,实现自立或另立,是对皇权的颠覆,僭越主要反映为超越礼制与等级界限,具体表现为行为的侵权。明文献对明宗室“谋逆”、“不轨”、僭越行为的定罪混淆,不仅是一个史观问题,而且一直影响到我们对这一问题的认识。     

Measurement of boiling heat transfer coefficient in liquid nitrogen bath by inverse heat conduction method

Inverse heat conduction method （IHCM） is one of the most effective approaches to obtaining the boiling heat transfer coefficient from measured results. This paper focuses on its application in cryogenic boiling heat transfer. Experiments were conducted on the heat transfer of a stainless steel block in a liquid nitrogen bath, with the assumption of a 1D conduction condition to realize fast acquisition of the temperature of the test points inside the block. With the inverse-heat conduction theory and the explicit finite difference model, a solving program was developed to calculate the heat flux and the boiling heat transfer coefficient of a stainless steel block in liquid nitrogen bath based on the temperature acquisition data. Considering the oscillating data and some unsmooth transition points in the inverse-heat-conduction calculation result of the heat-transfer coefficient, a two-step data-fitting procedure was proposed to obtain the expression for the boiling heat transfer coefficients. The coefficient was then verified for accuracy by a comparison between the simulation results using this expression and the verifying experimental results of a stainless steel block. The maximum error with a revised segment fitting is around 6%, which verifies the feasibility of using IHCM to measure the boiling heat transfer coefficient in liquid nitrogen bath.     

A novel posture alignment system for aircraft wing assembly

A novel 6-degree of freedom （DOF） posture alignment system, based on 3-DOF positioners, is presented for the assembly of aircraft wings. Each positioner is connected with the wing through a rotational and adsorptive half-ball shaped end-effector, and the positioners together with the wing are considered as a 3-PPPS （P denotes a prismatic joint and S denotes a spherical joint） redundantly actuated parallel mechanism. The kinematic model of this system is established and a trajectory planning method is introduced. A complete analysis of inverse dynamics is carried out with the Newton-Euler algorithm, which is used to find the desired actuating torque in the design and path planning phase. Simulation analysis of the displacement and actuating torque of each joint of the positioners based on inverse kinematics and dynamics is conducted, and the results show that the system is feasible for the posture alignment of aircraft wings.     

军事课：提高大学生逆商的利器

大学军事课在提高大学生逆商方面有着重要的作用。军事技能训练可以提升大学生自我控制意志力、责任感和持续性;军事理论学习可以促使其理解逆境,认识逆境并转化逆境。     

基于逆滤波法的图像复原技术研究

主要研究对已损坏了的图像恢复.它是利用退化现象的某种先验知识(退化模型),按退化的逆过程重建图像的技术.其退化模型是原始图像经过算子,或系统经退化因素作用之后和噪声叠加,形成退化后的图像,即实际得到的图像.利用逆滤波法复原的原理,通过已知复原图像和噪声,采用退化函数,经过反傅里叶变换,求出原始图象.同时以Visual C++6.0与Matlab为开发工具.实验表明本算法具有良好的性能,能有效抑制和清除干扰对测试结果的影响,具有算法简单可靠等优点,使图像质量得到改善.     

逆商培养:大学生创业有效执行力提升的着力点

培养逆商是提升大学生创业有效执行力的关键.在大学生创业观的树立中、在大学生创业教育模式构建中、在大学生创业教育课程设计与教学中、在大学生创业教育模拟实训和实践中突出逆商培养,能提升大学生创业有效执行力.     

基于基序及其时序关系的多变量数据流分类研究

多变量数据流精确分类问题是当前数据挖掘与信息领域的热点和难点,引起国内外越来越多研究群体的关注,但以往的研究大多依赖于从单个流中提取特征并进行分类,没有考虑数据流内以及数据流间特征的相互依赖关系.基于此,借鉴生物信息学中基序查找的方法,提出了长期频率和逆文档频率的分类方法,该方法主要是将每个输入流都转化为符号序列来描述信号变化特征,并将符号分为长度不同的块,以便更有效地提取基序;通过计算基序的频率、长期频率与逆文档频率的权重,用以衡量不同输入多变量数据流的基序之间的时序关系,并利用了基序与时序关系实现了对多变量数据流的分类,从而确保了多变量数据流分类的准确性,仿真实验的结果也证明该方法的有效性.     

贵金属到了低价区域

正大顺之后有大逆,大逆之后有大顺。天道轮回,皆如此。祸福总是相依而存,自2008年金融海啸之后,市场萎靡颓废,历经5年图治,全球经济渐有起色,十八届三中全会,中国改革进取,国内金融市场进入全新的开放时代,当此关键拐点和转折关口,生于敏感毁于迟钝与生于忧患死于安乐同样是我们必须铭记的竞争法则。本周,国家统计局公布的数据显示,2013年12月,中国居民消费价格指数(CPI)环比上涨0.3%,同比上涨