一类特殊的Sturm—Liouville问题第一特征值的估计

为了更精确地研究Sturm—Liouville问题第一特征值，本文主要讨论一类特殊的Sturm—Liouville问题第一特征值关于势函数的依赖性。应用变分原理，估计了此类特殊的研Sturm-Liouville问题第一特征值在不同参数值下的界限，并证明出其中的一些界限是可以达到的，为Sturm-Liouville问题第一特征值的逼近提供了更好的理论基础。     

制约现代汉语并列结构变动语序的因素

现代汉语并列结构无论是一般语序还是变动语序,都有其制约因素,从三方面来讨论制约并列结构变动语序的因素:凸显因素、语境因素和语音因素。     

Mini-research Experience in Simple Linear Regression

Within the undergraduate mathematics curriculum, the topic of simple least-squares linear regression is often first encountered in multi-variable calculus where the line of best fit is obtained by using partial derivatives to find the slope and y-intercept of the line that minimizes the residual sum of squares. A markedly different approach from linear algebra, which could also be introduced in multi-variable calculus, obtains the regression line by vector projection. The latter viewpoint offers elegant proof of the equation relating the total, explained and unexplained variations. Consideration of data with the same regression line and correlation opens the door for a “mini-research experience” (MRE). A sequel MRE gives rise to an open Research Experience for Undergraduates topic to analyze reflection sequences and a fundamental connection between complex analysis and regression analysis. A few general guidelines and basic goals for MREs are included for those whose main interest is in undergraduate research.     

Banach空间中各阶Bessel序列之间的包含关系

在Banach空间中 ,给出了各阶Bessel序列之间的包含关系     

基于Fibonacci数列的一种推广

介绍了经典的递推关系——Fibonacci数列的问题由来和数列描述，并以实际应用为背景，将此问题中的条件进一步一般化，得到新的序列，且对该序列的表达式，前后项比值等进行了一定的讨论。     

一种无回溯Web服务动态组合方法

可以把Web服务描述为一个关系,把Web服务的组合过程描述为关系间的运算．据此阐述了Web服务组合的关系模型,给出了相关定义,分析了一种用于消除合成语义冲突的领域级本体,给出了一种输入闭包的优化过程;通过建立服务组合序列,描述了Web服务组合方法,该方法简化Web服务的合成,具有无回溯、易于优化和易于实现的优点．     

析王蒙《蝴蝶》的“三合一”叙事结构

作为中国当代文学的泰斗级人物,王蒙的作品一直受到文艺工作者的重视。研究者往往从其作品的时代语境、作家的特殊际遇及其作品的时代意义入手,忽略了王蒙作品中叙事的生发策略与上述几要素之间的微妙关联。就此而言,文章的叙事研究对把握王蒙作品的整体内涵是必要而有意义的。     

循序渐进 因材施教

教学要有"序",这是一条传统的、也是基本的教学原则.就中学语文教学而言,作文教学如此,阅读教学更应如此.因为有了"序",方能循序而渐进、因材施教,收到良好的教学效果.     

用数字化定量分析物理课堂教学

文章用信息技术对物理课堂教学进行了教学行为的分类分析,得到了一系列可视化的数据。之后采用S-T分析数据,挖掘的关联算法,用一系列的数据分析出了教师课堂教学的教学风格,提问策略。最后根据分析出来的数据给出了相关的评价和建议。     

Time-domain training sequences design for MIMO OFDM channel estimation

This paper describes a Least Squares （LS） channel estimation scheme for MIMO OFDM systems based on time-domain training sequence. We first compute the minimum mean square error （MSE） of the LS channel estimation, and then derive the optimal criteria of the training sequence with respect to the minimum MSE. It is shown that optimal time-domain training sequence should satisfy two criteria. First, the autocorrelation of the sequence transmitted from the same antenna is an impulse function in a region longer than the channel maximum delay. Second, the cross-correlation between sequences transmitted from different antennas is zero in this region. Simulation results show that the estimator using optimal time-domain training sequences has better performance than that using optimal frequency training sequence at low signal-to-noise ratio （SNR）. To reduce the training overhead, a suboptimal training sequence is also proposed. Comparing with optimal training sequence, it has low computation complexity and high transmission efficiency at the expense of little performance degradation.