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．     

高Si/C高强度铸铁中C、Si、Si/C的作用及其选择

本文叙述了高Si/C高强度灰铸铁中碳、硅元素存在的形式及其对结晶过程的影响。试验表明,当碳当量一定时,随着Si/C的升高,初生奥氏体枝晶数量增多并且细化和强化,从而构成了强度的基础。该铸铁的强度模式应为“初生奥氏+共晶团”。本文对E型石墨存在的必然性和合理性也进行了讨论。     

Generalized Leverage and its Applications

The generalized leverage of an estimator is defined in regression models as a measure of the importance of individual observations. We derive a simple but powerful result, developing an explicit expression for leverage in a general M -estimation problem, of which the maximum likelihood problems are special cases. A variety of applications are considered, most notably to the exponential family non-linear models. The relationship between leverage and local influence is also discussed. Numerical examples are given to illustrate our results     

基于《巴塞尔Ⅲ最终方案》的弹性杠杆率监管研究

弹性资本充足率监管加刚性杠杆率监管存在机理性缺陷。弹性资本充足率监管会影响刚性杠杆率监管的效果,刚性杠杆率监管也不能体现杠杆累积在时间维度和空间维度风险的变化。若引入弹性杠杆率缓冲,刚性杠杆率监管加弹性资本充足率监管的机理性缺陷就可以避免。因此,有必要实施弹性杠杆率监管,杠杆率的弹性化程度与银行的系统重要性程度相对应。     

Notes on Interval Estimation of Odds Ratio in Matched Pairs under Stratified Sampling

We develop four asymptotic interval estimators and one exact interval estimator for the odds ratio (OR) under stratified random sampling with matched pairs. We apply Monte Carlo simulation to evaluate the performance of these five interval estimators. We note that the conditional score test-based interval estimator with a monotonic transformation and the interval estimator based on the Mantel–Haenszel (MH) type point estimator with the logarithmic transformation are generally preferable to the others considered here. We also note that the conditional exact confidence interval can be of use when the total number of matched pairs with discordant responses is small.     

New results on the likelihood ratio and score tests for the von Mises distribution

In this paper, we derive Bartlett and Bartlett-type corrections [G.M. Cordeiro and S.L.P. Ferrari 1991, A modified score test statistic having chi-squared distribution to order n ^?1 , Biometrika 78 (1991), pp. 573–582] to improve the likelihood ratio and Rao's score statistics for testing the mean parameter and the concentration parameter in the von Mises distribution. Simple formulae are suggested for the corrections valid for small and large values of the concentration parameter that do not depend on the modified Bessel functions and can be useful in practical applications.     

Influence Diagnostics on Testing Linear Hypothesis in Linear Models with Correlated Errors

To assess the influence of observations on the parameter estimates, case deletion diagnostics are commonly used in linear regression models. For linear models with correlated errors we study the influence of observations on testing a linear hypothesis using single and multiple case deletions. The change in likelihood ratio test and F test theoretically is derived and it is shown these tests to be completely determined by two proposed generalized externally studentized residuals. An illustrative example of a real data set is also reported.     

血栓弹力图在PCI术后患者抗血小板治疗中的应用研究

目的:研究血栓弹力图在经皮冠状动脉介入治疗(PCI)患者中,使用血栓弹力图所测定的血小板抑制率的波动及临床疗效作用。方法:选取我院2012年1月份至2013年12月份收治的200例冠心病PCI治疗患者,应用血栓弹力图分析仪测定其二磷酸腺苷(ADP)途径诱导的血小板抑制率数据,根据抑制率差异分为3组,抑制率70%的为合格组,抑制率30%的为不合格组,入选不合格组再次分为2组,1组保持常规剂量治疗不变,另一组为大剂量治疗组。结果:随访半年的记录,记录一般情况及严重心脏不良事件发生情况。结果:随访的6个月中,共发生不良事件28例,其中合格组10例(9.6%),常规治疗组11例(22.4%),大剂量治疗组7例(14.9%),3组中不良事件发生率比常规治疗组大于大剂量治疗组,大剂量治疗组大于合格组,统计学上有明显差异(P0.05)。结论:血栓弹力图在PCI患者抗血小板治疗中应用具有一定的指导意义。     

关于优化齐齐哈尔历史文化资源的思考

历史文化资源是城市特有文化形态的依托和我体。能否挖掘、保护、梳理好历史文化资源，关系到城市优秀历史文化的继承与弘扬，关涉到城市未来的发展与走向。历史文化资源，不但要挖掘、整理、保护，更要优化。优化历史文化资源，就是在文明的大背景下，系统梳理历史文化资源，理清历史发展脉络，理清文明发展足迹，理清优秀历史文化传统，进而树立鲜明的城市文化形象，增强城市文化软实力。     

Confidence intervals for the mean of a normal distribution with restricted parameter space

For a normal distribution with known variance, the standard confidence interval of the location parameter is derived from the classical Neyman procedure. When the parameter space is known to be restricted, the standard confidence interval is arguably unsatisfactory. Recent articles have addressed this problem and proposed confidence intervals for the mean of a normal distribution where the parameter space is not less than zero. In this article, we propose a new confidence interval, rp interval, and derive the Bayesian credible interval and likelihood ratio interval for general restricted parameter space. We compare these intervals with the standard interval and the minimax interval. Simulation studies are undertaken to assess the performances of these confidence intervals.