4G手机无线接入系统设计及实现

用射频微波电路集成技术设计第4代(4G)手机无线接入系统．从分布参数概念出发，主要在smith圆图上进行电路设计．由微带线进行电路的实现，电路将各功能单元集成在微带基板上，具有体积小、重量轻、可靠性高、与手机其他电路易于共形等特点．运用网络转移参量矩阵理论进行了系统响应预估，结果表明所设计的无线接入系统满足4G移动终端的性能要求．     

具有剩余寿命且排队空间有限的M/G/1排队模型非负解的存在唯一性

研究了以剩余寿命作为增补变量,排队空间有限的M/G/1排队模型,利用泛函分析中线性算子半群的积分半群理论讨论了该模型的瞬态解的存在唯一性问题。     

空铁联运网络的模型构建与算法设计

针对空铁联运网络具体联运路径的设计问题,借鉴枢纽航线网络p-枢纽中位问题的研究思想,将非枢纽城市间可以直航考虑进去,以联运网络总成本最低为目标函数,构建了允许直航的空铁联运网络混合整数规划模型,并设计了基于遍历搜索的最短路算法来求解模型.最后选取样本城市对模型和算法进行算例分析,给出了不同参数组合下的最优目标值和具体联运路径,设计了中国14个城市的空铁联运网络.算例结果表明联运总成本大小和联运路径的数目与枢纽数目m、折扣系数ρ紧密相关:m越大,ρ越小,联运总成本越小,联运路径数目越多;反之亦然.     

Characterizing STEM Teacher Education: Affordances and Constraints of Explicit STEM Preparation for Elementary Teachers

Although science, technology, engineering, and mathematics (STEM) education sits at the center of a national conversation, comparatively little attention has been given to growing need for STEM teacher preparation, particularly at the elementary level. This study analyzes the outcomes of a novel, preservice STEM teacher education model. Building on both general and STEM‐specific teacher preparation principles, this program combined two traditional mathematics and science methods courses into one STEM block. Analysis compared preservice teachers in the traditional courses with those enrolled in the STEM block, investigating STEM teaching efficacy, reported and exhibited pedagogical practices, and STEM literacies using a pre‐post survey as well as analysis of lesson planning products. Linear regression models indicated that substantial growth was seen in both approaches but STEM block preservice teachers reported significantly greater gains in STEM teaching efficacy as compared with traditional‐route teachers. Lesson planning artifacts also demonstrated increased facilitation of STEM literacies, with specific attention to content integration, engineering and design, and arts inclusion. Technology and computational thinking emerged as areas for further growth and clarification in STEM teacher education models. Findings contribute to a growing research base on developing the STEM teacher workforce.     

146号初等元胞自动机的演化语言的复杂性

Symbolic dynamics of cellular automata is introduced by coarse-graining the temporal evolution orbits. Evolution languages are defined. By using the theory of formal languages and automata, the complexity of evolution languages of the elementary cellular automaton of rule 146 is studied and it is proved that its width 1-evolution language is regular, but for every n ≥ 2 its width n-evolution language is not context-free but context-sensitive. Also, the same results hold for the equivalent （under conjugation） elementary cellular automaton of rule 182.     

“后配额时代”中国纺织品服装出口预测

本文利用单整自回归移动平均模型,依据2000年1月至2004年12月中国纺织品服装出口额数据,对2005年和2006年中国纺织品服装出口走势进行预测分析。     

Local Power Properties of Kernel Based Goodness of Fit Tests

If (X_i, i ) is a strictly stationary process with marginal density function f, we are interested in testing the hypothesis H₀: {f=f₀}, where f₀ is given. We consider different test statistics based on integrated quadratic forms measuring the proximity between f_n, a kernel estimator of f, and f₀, or between f_n and its expected value computed under H₀. We study the asymptotic local power properties of the testing procedures under local alternatives. This study generalizes to the multidimensional case in a context of dependence the corresponding one made by P. J. Bickel and M. Rosenblatt in 1973 (Ann. Statist.1, 1071–1095).     

对于金融资产漂移函数估计的双域组合方法(英文)

Time-domain state-domain methods are common approaches in modern financial analysis.Economic conditions vary time,drift function depends on time and price level for a given state variable.In this paper,to consistently estimate the bivariate drift function,our purpose a new dynamic integrated estimator by combing time-and state-domain methods for estimating drift function.And we establish its asymptotic properties and illustrates it outperforms some old ones by simulations.     

插值多项式在一重积分Wiener空间下的同时逼近平均误差

本文在加权L_p范数逼近意义下确定了基于第一类Chebyshev 结点组的Lagrange 插值多项式列在一重积分Wiener 空间下同时逼近平均误差的渐近阶. 结果显示在L_p范数逼近意义下Lagrange 插值多项式列的平均误差弱等价于相应的最佳逼近多项式列的平均误差. 同时, 当2≤p≤4 时,Lagrange 插值多项式列导数逼近的平均误差弱等价于相应的导数最佳逼近多项式列的平均误差. 作为对比, 本文也确定了相应的Hermite-Fejér 插值多项式列在一重积分Wiener空间下逼近的平均误差的渐近阶.     

基于ARIMA与神经网络集成的GDP时间序列预测研究

本文深入分析了单整自回归移动平均(ARIMA)模型与神经网络(NN)模型的预测特性和优劣,并在此基础上建立了由ARIMA模型和NN模型集成的GDP时间序列预测模型与算法。其基本思想是充分发挥两种模型在线性空间和非线性空间的预测优势,据此将GDP时间序列的数据结构分解为线性自相关主体和非线性残差两部分,首先用ARIMA模型预测序列的线性主体,然后用NN模型对其非线性残差进行估计,最终集成为整个序列的预测结果。仿真实验表明:集成模型的预测准确率显著高于单一模型的预测准确率,从而证实了集成模型用于GDP预测的有效性。