冲激噪声环境中LFM信号的特征参数估计

SαS稳定分布是一类非常重要的非高斯随机分布,具有这类分布的噪声称为冲激噪声。在冲激噪声情况下,α阶以上的矩均不存在,导致基于二阶矩的高斯模型算法性能下降,甚至不能正常工作。该文提出了一种在冲激噪声环境下线性调频信号特征参数估计的算法,通过分析冲激噪声的具体特点,给出了修正的低阶矩模糊函数,并结合Radon变换估计了冲激噪声环境下LFM信号的参数。该算法既可应用于冲激噪声下,又可应用于高斯噪声环境,故具有较好的鲁棒性。最后用计算机仿真验证了该算法的有效性。     

超深亚微米信号串扰分析

芯片设计进入深亚微米后,互连线效应(主要是信号串扰)对集成电路的影响越来越大。该文针对这种影响进行了分析,讨论了在不考虑耦合电容和考虑耦合电容的两种情况下噪声产生机理,建立了一个耦合电容分析模型,得出了噪声产生的原因,并提出了解决噪声的策略。根据设计实例并结合建立的模型,提出了实际芯片设计中有效地控制串扰的方法,取得了良好的效果。     

区域经济一体化对世界福利及多边贸易体制的影响

随着经济的全球化,在以GATT和WTO为代表的多边贸易自由化不断深化的同时,区域经济一体化组织层出不穷。而区域经济一体化对于世界福利和多边贸易是有利有弊的。因此,在政策制定上要扬长避短,既限制其不利的影响,同时又要积极发挥它的积极作用。     

音像业全球化趋势与我国音像业对外经贸策略的创新

在音像业全球化趋势下,尤其是随着加入WTO,我国音像业在对外经贸策略和规章方面存在的诸多问题日益暴露出来。因此,针对我国音像业对外经贸策略的不足,积极对音像业对外经贸策略进行创新,具有重要的理论价值和现实意义。     

归入权问题之研究

通过对归入权行使对象、行使主体、行使范围的论述 ,对《证券法》第 42条的修改提出了相关建议 :归入权行使对象应当扩大 ,行使主体不仅应包括董事会、监事会、股东 ,在一定条件下 ,证监会也可以作为行使主体。在计算归入权的收益上可采取最高卖价减最低买价法予以计算。     

Sampling Returns for Realized Variance Calculations: Tick Time or Transaction Time?

This article introduces a new model for transaction prices in the presence of market microstructure noise in order to study the properties of the price process on two different time scales, namely, transaction time where prices are sampled with every transaction and tick time where prices are sampled with every price change. Both sampling schemes have been used in the literature on realized variance, but a formal investigation into their properties has been lacking. Our empirical and theoretical results indicate that the return dynamics in transaction time are very different from those in tick time and the choice of sampling scheme can therefore have an important impact on the properties of realized variance. For RV we find that tick time sampling is superior to transaction time sampling in terms of mean-squared-error, especially when the level of noise, number of ticks, or the arrival frequency of efficient price moves is low. Importantly, we show that while the microstructure noise may appear close to IID in transaction time, in tick time it is highly dependent. As a result, bias correction procedures that rely on the noise being independent, can fail in tick time and are better implemented in transaction time.     

从分笔交易数据透视中国债券市场流动性

采用分笔交易数据,用相对买卖价差分析我国债券市场流动性,可以得出如下结论:各期限国债流动性差异不大,短期和长期国债流动性相对较好;国债买卖价差最小,可转债累计深度最大;债券市场流动性和波动性特征之间存在紧密的内在联系。     

证交所国债买断式回购交易的风险研究

国债买断式回购的推出衍生了抛补套利、循环融券卖空、债券组合交易、买断式回购组合交易这几种新的主要交易模式,丰富了投资者的交易手段,然而,这些新的交易模式将容易引发做空风险、流动性风险和更大的信用风险,在分析这些风险的基础上,提出了建立健全保证金制度、信用评估制度以及制定严格的交易规则等风险防范对策。     

Expected sample moments of concomitants of selected order statistics

In this paper, the task of determining expected values of sample moments, where the sample members have been selected based on noisy information, is considered. This task is a recurring problem in the theory of evolution strategies. Exact expressions for expected values of sums of products of concomitants of selected order statistics are derived. Then, using Edgeworth and Cornish-Fisher approximations, explicit results that depend on coefficients that can be determined numerically are obtained. While the results are exact only for normal populations, it is shown experimentally that including skewness and kurtosis in the calculations can yield greatly improved results for other distributions.     

视频在IP网络中传输的质量研究

利用MEPEG-4视频TRACE作为输入源,通过分析MPEG-4视频的帧特性,提出了一种针对视频质量的网络传输服务质量保证机制;搭建了视频传输的仿真系统,分析了视频在网络传输中的特性,利用PSNR作为视频质量的衡量标准,在有服务质量保证和无服务质量保证机制的两种网络环境下做了仿真并比较结果,证明了提出的方法能有效提高视频质量．