基于四阶累积量的CSPRIT算法     

沈怡平  侯朝焕  马晓川 《中国科学院研究生院学报》2007,24(3):325-330

分析了基于二阶统计的CSPRIT算法在空间相关高斯噪声环境中存在的问题，提出将四阶累积量与CSPRIT算法相结合，处理一维二元相移键控信号（BPSK）和多元幅移键控信号（MASK），实现信号到达角（DOA）的估计和波束形成器的构造。与基于二阶统计的CSPRIT算法相比，基于四阶累积量的改进算法能够有效抑制空间相关的高斯噪声，提高信号估计精度。计算机仿真验证了该算法的有效性。  相似文献   

A novel controller design and evaluation for networked control systems with time-variant delays     

Li Zhang  Fang Hua-Jing 《Journal of The Franklin Institute》2006,343(2):161-167

A new delayed state-variable model for networked control systems is presented, upon which a linear quadratic regulator (LQR) is designed. A method of delays-estimation online is also given. A fuzzy logic with LQR controller is addressed for the difficulty on implementation of LQR in networked control systems (NCSs) with time-variant delays. Simulation results prove that the novel controller can make the system stable and robustly preserve the performance in terms of time-variant delays.  相似文献   

用偏最小二乘法提取石头口门水库水色信息   总被引：1，自引：0，他引：1  

徐京萍  张柏  宋开山  王宗明  刘殿伟  段洪涛 《中国科学院研究生院学报》2007,24(6):814-849

水体的高光谱数据在提供大量信息的同时，其波段间存在很高的相关性，常规的统计方法反演水质参数不但不能充分利用这些信息，并且也不能很好的去相关，而偏最小二乘回归分析可以较好的解决这一问题。因此本研究通过利用高光谱仪在石头口门水库进行反射光谱测量和同步水质采样分析，建立了叶绿素a和悬浮物含量的偏最小二乘回归模型。结果表明：该模型能较好的利用高光谱数据信息，各光谱波段自变量在最终模型中的系数大小在一定程度上较符合叶绿素a和悬浮物的光谱吸收、散射特性；通过与常规的比值模型、一阶微分模型进行对比，偏最小二乘回归模型明显优于前两者，其各决定系数均高于0.7，因此估测效果较理想，可用于内陆二类水体的水色信息提取。  相似文献   

Estimation of 2-D ARMA model parameters by using equivalent AR approach     

Ayd?n K?z?lkaya 《Journal of The Franklin Institute》2005,342(1):39-67

In this paper, the problem of estimating the parameters of a two-dimensional autoregressive moving-average (2-D ARMA) model driven by an unobservable input noise is addressed. In order to solve this problem, the relation between the parameters of a 2-D ARMA model and their 2-D equivalent autoregressive (EAR) model parameters is investigated. Based on this relation, a new algorithm is proposed for determining the 2-D ARMA model parameters from the coefficients of the 2-D EAR model. This algorithm is a three-step approach. In the first step, the parameters of the 2-D EAR model that is approximately equivalent to the 2-D ARMA model are estimated by applying 2-D modified Yule-Walker (MYW) equation to the process under consideration. Then, the moving-average parameters of the 2-D ARMA model are obtained solving the linear equation set constituted by using the EAR coefficients acquired in the first step. Finally, the autoregressive parameters of the 2-D ARMA model are found by exploiting the values obtained in first and second steps. The performance of the proposed algorithm is compared with other 2-D ARMA parameter and spectral estimation algorithms available in the technical literature by means of three different criteria. As a result of this comparison, it is shown that the parameters and the corresponding power spectrums estimated by using the proposed algorithm are converged to the original parameters and the original power spectrums, respectively.  相似文献   

巴斯卡分布NB(r,p)中参数r的估计   总被引：1，自引：0，他引：1  

林金官 《科技通报》2002,18(6):484-489

巴斯卡分布NB（r,p)是重要的离散型分布之一，当r已知时，巴斯卡分布NB（r,p)中未知参数p(p∈（0，1））的估计是众所周知的。本文分别在p已知和未知的条件下，研究了参数r(r∈（1，2，…}）的估计，并得到了它们的渐近性质。  相似文献   

Robust estimator design with an emphasis balance between performance and robustness     

Hyeon-Cheol Lee  Don R. Halverson 《Journal of The Franklin Institute》2007,344(7):954-968

From a number of ML estimators (typically unbiased) of practical interest which include the variance for a Gaussian distribution, the standard deviation for a Laplace distribution, the variance for a Rayleigh distribution and a “spread parameter” for a Cauchy distribution, we design robust estimators according to an emphasis balance between normalized performance and normalized robustness. We measure performance with inverted MSE and robustness with a differential geometric approach.  相似文献   

A large-scale donor attempt to improve educational status of the poor and household income distribution: The experience of PEDC in Vietnam     

Roy A. Carr-Hill 《International Journal of Educational Development》2011

In 2003, donors combined together in Vietnam to support the provision of quality primary schooling for 226 disadvantaged districts (about a third of the country). US$160 million was invested in infrastructure, materials and training across the 226 districts. The programme has been commended by donors and received good press inside Vietnam. Comparison of achievement surveys in 2001 and 2007 showed, however, that there had been a decline in performance in the targeted districts. This article explores various hypotheses as to how this could have happened; and in particular the increasing amounts spent by better-off households on their children's education.  相似文献   

Student satisfaction with Canadian music programmes: the application of the American Customer Satisfaction Model in higher education     

Alexander Serenko 《Assessment & Evaluation in Higher Education》2011,36(3):281-299

The purpose of this project is to empirically investigate several antecedents and consequences of student satisfaction (SS) with Canadian university music programmes as well as to measure students’ level of programme satisfaction. For this, the American Customer Satisfaction Model was tested through a survey of 276 current Canadian music students. The results indicate that customer satisfaction is strongly affected by programme quality, is slightly impacted by its perceived value but is not influenced by prior student expectations. Satisfaction strongly increases programme loyalty and positive word‐of‐mouth, marginally raises tuition change loyalty, and slightly decreases complaining behaviour. Contrary to expectations, tuition‐related constructs play only a minor role in the model. Therefore, money is a marginal factor in the educational environment; this empirically demonstrates the flaws underlying the premises of the students‐as‐customers metaphor. The resulting satisfaction index may facilitate the comparison among institutions. It was also found that the level of SS with Canadian music programmes was somewhat lower than those with services in other industries.  相似文献   

利用线性规划方法建立回归方程     

邹自德 《广州广播电视大学学报》2011,11(6):103-105,112

本文利用最小一乘法建立线性回归模型,应用线性规划方法确定回归系数,从而建立线性回归方程。这样做有两方面好处,其一是提高了拟合精度;其二是有现成的计算机软件可用,从而使求解工作量大为减小。  相似文献   

金融危机企业资产负债表模型对我国的适用性检验-基于动态面板数据模型的分析          下载免费PDF全文

邢勇  谭本艳 《科研管理》2011,32(2):128-135

摘要：本文根据我国522家制造业上市公司2001-2007年的财务数据,建立动态面板数据模型,分析了Krugman(1999)提出的金融危机企业资产负债表模型对我国的适用性。研究结论认为,在企业存在货币错配的情况下,人民币汇率波动对企业的短期信贷能力有显著的影响,但对长期信贷能力的影响还不明显。而且,这种影响是动态的,人民币汇率波动的滞后1期值比当期值对企业信贷能力的影响更加明显。因而,金融危机企业资产负债表模型对我国具有适用性。    相似文献