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本文从《中国保险年鉴》和中国保监局广东省监管局网站获取广东省(不含深圳)财产保险业统计数据,应用移动平均值法和适应性预期法对赔付率进行平滑;鉴于赔付率数据能够较好拟合差分自回归移动平均模型,采用小波降噪去除白噪声的方法,平滑赔付率数据。三种方法中,小波降噪平滑后的数据与原数据误差最小,平滑效果最好。三种平滑方法均能够抵消巨额未决赔款拉低总产出的影响,较好地平滑了财产保险业的总产出。 相似文献
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介绍了新兴的独立分量分析技术的基本概念和原理,以及具有代表性的算法,即FastICA算法、EASI算法、非线性PCA算法和基于自然梯度的最大似然估计算法。通过降噪仿真实验,并采用均方误差作为降噪的性能指数,对这些算法与传统的自适应信号处理算法进行比较。所得实验结果表明,独立分量分析算法在降噪上的效果优于自适应信号处理算法。因此在降噪上具有较大的应用价值。 相似文献
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小波阈值去噪方法被广泛地用在信号去噪中,但它主要是针对白噪声或者宽带噪声,对于脉冲噪声就得不到降噪的效果。该文提出了小波域的中值滤波器去噪方法,在Lee的局部滤波器基础上设计了小波域的中值滤波器,它能在有效去除白噪声的同时较好地去除脉冲噪声。 相似文献
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针对常用的滤波去噪方法都受到使用条件的限制,实际资料的滤波去噪不能达到良好效果,S变换时变滤波克服了传统滤波去噪方法滤波因子不能随时间、频率变化而变化的缺陷。将地震资料用S变换方法变换到时频域,对不同时间内不同频率的噪声部分充零,再将去噪后的地震数据利用S反变换到时间域,以获得所需要的有效信号。通过理论计算分析和实例计算表明,S变换时变滤波能够有效去除不同时段、不同频率的噪声。该方法具有一定的可行性。 相似文献
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基于稀疏分解的图像去噪 总被引:1,自引:0,他引:1
基于稀疏分解的图像去噪处理是将被噪声污染的图像分解成图像的稀疏成分和其他成分。稀疏成分对应于图像中的有用信息,其他成分对应于图像中的噪声。由图像的稀疏成分重建图像,可达到去除图像噪声的目的。实验结果表明基于稀疏分解的图像去噪处理具有一定的效果。 相似文献
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In this article, a novel hybrid method to forecast stock price is proposed. This hybrid method is based on wavelet transform, wavelet denoising, linear models (autoregressive integrated moving average (ARIMA) model and exponential smoothing (ES) model), and nonlinear models (BP Neural Network and RBF Neural Network). The wavelet transform provides a set of better-behaved constitutive series than stock series for prediction. Wavelet denoising is used to eliminate some slight random fluctuations of stock series. ARIMA model and ES model are used to forecast the linear component of denoised stock series, and then BP Neural Network and RBF Neural Network are developed as tools for nonlinear pattern recognition to correct the estimation error of the prediction of linear models. The proposed method is examined in the stock market of Shanghai and Shenzhen and the results are compared with some of the most recent stock price forecast methods. The results show that the proposed hybrid method can provide a considerable improvement for the forecasting accuracy. Meanwhile, this proposed method can also be applied to analysis and forecast reliability of products or systems and improve the accuracy of reliability engineering. 相似文献
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张天瑜 《华南农业大学学报(社会科学版)》2011,(1)
图像在采集、获取以及传输的过程中,往往要受到噪声的污染,形成噪声图像。图像去噪是图像处理领域中的一个重要环节。为了对含有高斯白噪声的图像进行去噪,在Donoho提出的小波阈值去噪算法的基础上,提出一种基于维纳滤波的小波图像去噪算法,利用维纳滤波后剩下的信号来计算噪声的标准方差。仿真结果表明,与Donoho提出的鲁棒中值算法相比,该算法能够有效地抑制高斯白噪声,更好地保留图像的边缘细节。 相似文献
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We propose a class of methods for graphon estimation based on exploiting connections with nonparametric regression. The idea is to construct an ordering of the nodes in the network, similar in spirit to Chan & Airoldi (2014). However, rather than considering orderings based only on the empirical degree as in Chan & Airoldi (2014), we use the nearest-neighbour algorithm which is an approximative solution to the travelling salesman problem. This algorithm in turn can handle general distances between the nodes, allowing us to incorporate rich information from the network. Once an ordering is constructed, we formulate a two-dimensional-grid graph-denoising problem that we solve through fused-lasso regularization. For particular choices of the metric , we show that the corresponding two-step estimator can attain competitive rates when the true model is the stochastic block model, and when the underlying graphon is piecewise Hölder or has bounded variation. 相似文献
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