保图像细节的DWAWMTMF算法

提出双窗自适应加权中值-截尾均值滤波算法。根据信号结构特征设计出自适应计算滤波参数的方法,该方法在抑制加性混合噪声和保图像细节等方面有优良的性能,综合性能优于3LH+、DWMTMF、ACWM。     

试论英语教学中的“情感过滤”

“情感过滤”和“输入”是影响外语习得的两大重要因素。该文首先论述了“情感过滤”对外语习得和学习的作用机制 ,然后分析了引起“情感过滤”的四大情感因素 ,并提出怎样减少或消除学习者的“情感过滤”来提高英语教学质量的方法。     

Prediction and forecasting in linear models with measurement error

We consider measurement error models within the time series unobserved component framework. A variable of interest is observed with some measurement error and modelled as an unobserved component. The forecast and the prediction of this variable given the observed values is given by the Kalman filter and smoother along with their conditional variances. By expressing the forecasts and predictions as weighted averages of the observed values, we investigate the effect of estimation error in the measurement and observation noise variances. We also develop corrected standard errors for prediction and forecasting accounting for the fact that the measurement and observation error variances are estimated by the same sample that is used for forecasting and prediction purposes. We apply the theory to the Yellowstone grizzly bears and US index of production datasets.     

Bayesian Analysis of an Unobserved-Component Time Series Model of GDP With Markov-Switching and Time-Varying Growths

We propose an unobserved-component time series model of gross domestic product that includes Markov switching as an unobserved component. In addition to a trend component, the model has two time-varying drift components. One drift represents the expected rate of growth during recession; the other drift represents the expected rate during expansion. Estimates indicate a substantial decline in the latter annual rate for the United States from 6.4% in 1950 to 3.6% by 1990. We have employed weak priors based on prewar data. The estimation makes use of the Gibbs sampler and the Metropolis algorithm.     

Estimation of an Asymmetric Stochastic Volatility Model for Asset Returns

A stochastic volatility model may be estimated by a quasi-maximum likelihood procedure by transforming to a linear state-space form. The method is extended to handle correlation between the two disturbances in the model and applied to data on stock returns     

Evaluating Efficiency-Equality Tradeoffs for Mobile Source Control Strategies in an Urban Area

In environmental risk management, there are often interests in maximizing public health benefits (efficiency) and addressing inequality in the distribution of health outcomes. However, both dimensions are not generally considered within a single analytical framework. In this study, we estimate both total population health benefits and changes in quantitative indicators of health inequality for a number of alternative spatial distributions of diesel particulate filter retrofits across half of an urban bus fleet in Boston, Massachusetts. We focus on the impact of emissions controls on primary fine particulate matter (PM_2.5) emissions, modeling the effect on PM_2.5 concentrations and premature mortality. Given spatial heterogeneity in baseline mortality rates, we apply the Atkinson index and other inequality indicators to quantify changes in the distribution of mortality risk. Across the different spatial distributions of control strategies, the public health benefits varied by more than a factor of two, related to factors such as mileage driven per day, population density near roadways, and baseline mortality rates in exposed populations. Changes in health inequality indicators varied across control strategies, with the subset of optimal strategies considering both efficiency and equality generally robust across different parametric assumptions and inequality indicators. Our analysis demonstrates the viability of formal analytical approaches to jointly address both efficiency and equality in risk assessment, providing a tool for decisionmakers who wish to consider both issues.     

高等学校岗位绩效工资实施策略研究

在非线性条件下，扩展Kalman滤波(EKF)的应用最为广泛。但是，由于它采用了Taylor展开的线性变换来近似非线性模型，因而存在计算量大、实时性差、估计精度低等缺点。粒子滤波(PF)用一些带有权值的随机样本(粒子)来表示所需要的后验概率密度，并通过这些粒子的加权来估计目标运动的状态，从而得到基于物理模型的近似最优数值解，具有精度高、收敛速度快等特点。通过仿真实验将PF与EKF的性能进行了对比，并且研究了噪声协方差与粒子数对PF的影响。PF与EKF的对比实验结果表明，在强非线性条件下，PF比EKF跟踪精     

时滞交联系统的H_∞滤波设计

基于T-S模糊模型方法,针对一类时滞交联系统,提出了一种集中H∞滤波设计新方案.通过构造新的模糊线积分李雅普诺夫泛函,给出了整体滤波误差系统时滞相关的集中H∞滤波设计LMI条件,降低了性能指标的保守性.最后通过仿真例子说明了所提方法的有效性和优越性.     

计算机网络安全与防火墙技术

计算机网络的不断发展,加快了我国企业和全社会信息化的脚步,同时网络安全问题已成为信息时代人类共同面临的挑战,网络安全问题也日益突出。全面分析了目前计算机网络安全问题,探讨了网络安全策略,通过主要的防火墙技术来分析如何提高网络安全性能,从而保证网络的安全。     

光热反射实验中微弱信号的测量

介绍了用激光光热反射方法测量表面下物体热物性的实验原理.分析了实验中噪声的主要来源,运用带通滤光片结合差分探测的方式降低激光器产生的噪声.锁相放大技术对被测信号进行窄带放大,锁相放大器结合示波器输出了被测信号的周期变化部分,实现了光热法测量中微弱信号的测量.