A simple channel estimator for space-time coded OFDM systems in rapid fading channels     

单淑伟  罗汉文  宋文涛 《浙江大学学报(A卷英文版)》2004,5(1):45-49

A simple channel estimator for space-time coded orthogonal frequency division multiplexing (OFDM) systems in rapid fading channels is proposed. The channels at the training bauds are estimated using the EM (expectation-maximization) algorithm, while the channels at the data bauds are estimated based on the method for modelling the time-varying channel as the linear combination of several time-invariant "Doppler channels". Computer simulations showed that this estimator outperforms the decision-directed tracking in rapid fading channels and that the performance of this method can be improved by iteration.  相似文献   

基于遗传算法的阵列相位误差校正     

刘颖 《天津工程师范学院学报》2007,17(3):26-28,32

针对声纳水听器阵列比较突出的相位误差,研究了一种基于遗传算法的阵列校正方法。该方法利用无相位误差时阵列协方差矩阵具有Toeplitz结构的特性构造代价函数,并以此作为遗传算法中进化个体的适应度函数,由算法搜索的最优个体得到阵元相位误差的估值。计算机仿真结果表明,该方法可以明显地减小阵列相位误差对MUSIC算法DOA估计结果的影响。  相似文献   

《体育(与健康)课程标准》实施后的评价     

苏煜  薛端萍 《沈阳教育学院学报》2006,8(3):143-145

通过文献资料法，研究《体育（与健康）课程标准》实施中，学术界对其方方面的评价。分析了《体育（与健康）课程标准》的可行性，并通过发现的问题，进一点提出完善《体育（与健康）课程标准》的操作性建议。  相似文献   

多变量系统的结构辩识和参数估计     

刘轩黄 《江西电力职业技术学院学报》2001,14(4):1-9

将单输入 单输出 (SISO)系统的递推辩识算法推广到多变量的情形 ,这种最小二乘类型的算法结构简洁且可同时给出具有良好数值性质的模型结构和参数辩识。证明了多变量输入 输出差分方程模型与其对应的标准状态空间模型可以经变换而由一种模型得到另一种模型。该算法与对应的最小二乘递推算法比较更易于理解和实现  相似文献   

Bayesian Regularized Multivariate Generalized Latent Variable Models     

Xiang-Nan Feng  Xin-Yuan Song 《Structural equation modeling》2017,24(3):341-358

We consider a multivariate generalized latent variable model to investigate the effects of observable and latent explanatory variables on multiple responses of interest. Various types of correlated responses, such as continuous, count, ordinal, and nominal variables, are considered in the regression. A generalized confirmatory factor analysis model that is capable of managing mixed-type data is proposed to characterize latent variables via correlated observed indicators. In addressing the complicated structure of the proposed model, we introduce continuous underlying measurements to provide a unified model framework for mixed-type data. We develop a multivariate version of the Bayesian adaptive least absolute shrinkage and selection operator procedure, which is implemented with a Markov chain Monte Carlo (MCMC) algorithm in a full Bayesian context, to simultaneously conduct estimation and model selection. The empirical performance of the proposed methodology is demonstrated through a simulation study. An application of the proposed method to a study of adolescent substance abuse based on the National Longitudinal Survey of Youth is presented.  相似文献   

基于指数分布预测问题的研究     

林穗华 《南宁师范高等专科学校学报》2007,24(4):135-137

本文主要运用贝叶斯统计的理论与方法,对截尾寿命试验根据其早期结果预测下一个失效时间,并对指数分布情形下的失效时间,进行了详细的讨论,得出其下一个失效时间的点估计与区间估计,并进行随机模拟。  相似文献   

基于2PLM项目参数估计的病态矩阵控制     

周明元  方光伟 《宜春学院学报》2004,26(6):49-52

病态矩阵是IRT理论中项目参数估计必然面对的问题．本文以2PLM参数估计为例．推导出参数估计迭代公式，系统阐述了三种病态控制方法的原理及在编程中数据处理的技巧。  相似文献   

Using the United States Census Data to Introduce Differential Equations     

Jean Marie Linhart 《PRIMUS》2019,29(7):702-711

Abstract

This article describes a method for using the United States Census data to open a differential equations course. The question of finding a model for the United States population data gives students a first experience with creating a model using differential equations, and also understanding derivatives, what they mean, and how to calculate them in the context of real data. This model-building start motivates further exploration in many of the standard differential equations topics: the method of separation of variables, slope fields, autonomous equations, equilibria, and stability.  相似文献   

变系数回归模型的参数估计   总被引：2，自引：0，他引：2  

欧阳光 《湘南学院学报》2005,26(2):15-19,22

讨论了变系数回归模型中变系数的加权最小二乘估计和变系数的加权可估函数的线性估计的最优性;推广了Gauss-Markov定理;并且构造出参数σ2的估计量.  相似文献   

谈如何利用联想解题     

杨秀芹 《漯河职业技术学院学报》2004,3(4):43-45

在基础教育中，如何通过对知识的联想来采集信息，解决问题是一种提高教学的有效途径。  相似文献