异构P2P网络的分布式查询协议

从P2P网络节点的异构性出发,考虑了节点物理位置,提出了一种分层的混合路由查询协议。该协议利用时间戳在局部实现了节点逻辑位置和物理位置的统一,并引入超级节点解决了节点负载失衡和性能瓶颈的问题。在仿真平台P2PSim上的性能测试表明,该协议在大规模P2P网络中优于Kademlia、Chord、Tapestry。     

《蝴蝶君》对性别和种族的解构

美籍华裔剧作家黄哲伦的作品《蝴蝶君》自问世以来广受关注,剧中通过性别角色的转换和种族关系的颠覆来阐述解构主义思想,表达了要求东西方平等相待的愿望。     

开拓毕业设计教学改革思路 培养高质量技术人才

本文结合计算机科学与技术专业多年来毕业设计教学改革的探索与实践,总结了相关的教改工作经验,并针对存在的问题提出了解决对策,开拓了深化改革的思路,对如何适应新形势,培养高质量有用技术人才有重要指导意义.     

On quantile residuals in beta regression

Beta regression is often used to model the relationship between a dependent variable that assumes values on the open interval (0, 1) and a set of predictor variables. An important challenge in beta regression is to find residuals whose distribution is well approximated by the standard normal distribution. Two previous works compared residuals in beta regression, but the authors did not include the quantile residual. Using Monte Carlo simulation techniques, this article studies the behavior of certain residuals in beta regression in several scenarios. Overall, the results suggest that the distribution of the quantile residual is better approximated by the standard normal distribution than that of the other residuals in most scenarios. Three applications illustrate the effectiveness of the quantile residual.     

Non-parametric Estimation of the Residual Distribution

Consider a heteroscedastic regression model Y = m ( X ) +σ( X )ε, where the functions m and σ are smooth, and ε is independent of X . An estimator of the distribution of ε based on non-parametric regression residuals is proposed and its weak convergence is obtained. Applications to prediction intervals and goodness-of-fit tests are discussed.     

Deletion residuals in the detection of heterogeneity of variances in linear regression

The heterogeneity of error variance often causes a huge interpretive problem in linear regression analysis. Before taking any remedial measures we first need to detect this problem. A large number of diagnostic plots are now available in the literature for detecting heteroscedasticity of error variances. Among them the ‘residuals’ and ‘fits’ (R–F) plot is very popular and commonly used. In the R–F plot residuals are plotted against the fitted responses, where both these components are obtained using the ordinary least squares (OLS) method. It is now evident that the OLS fits and residuals suffer a huge setback in the presence of unusual observations and hence the R–F plot may not exhibit the real scenario. The deletion residuals based on a data set free from all unusual cases should estimate the true errors in a better way than the OLS residuals. In this paper we propose ‘deletion residuals’ and the ‘deletion fits’ (DR–DF) plot for the detection of the heterogeneity of error variances in a linear regression model to get a more convincing and reliable graphical display. Examples show that this plot locates unusual observations more clearly than the R–F plot. The advantage of using deletion residuals in the detection of heteroscedasticity of error variance is investigated through Monte Carlo simulations under a variety of situations.     

分布式并行服务器中的高性能通信研究

基于快速以太局网中分布式并行服务器通信特点和对网络协议栈的分析,设计并实现了一种分布式操作系统传输协议。该协议在维持通用编程接口的同时,精简网络协议栈底层的冗余操作,减少操作系统干预和协议自维护开销。在8个节点的服务器系统上的测试结果表明,分布式操作系统传输协议获得比用户数据报协议更小的往返延迟和系统开销,应用环境下有约20%的增益,能有力地支持系统扩展和大并发访问服务。     

Do greater amounts of FDI cause higher pollution levels? Evidence from OECD countries

Using an ARDL model for a panel of 15 OECD countries, this work analyses the impact that FDI, both jointly and by sector, has on CO₂ emissions. The findings reveal that these countries are yielding to the pressure on the trade sector. Unexpectedly, gross fixed capital formation shrink pollution, excluding in the mining sector. With findings supporting the Pollution Haven Hypothesis, policymakers must pay attention to FDI inflows, ensuring that FDI place high importance on the transfer of green technologies to improve the efficiency. These goals could be achieved through an increase in the stringency of environmental laws within the host countries, especially the ones related to FDI.     

经济增长由投资拉动转向消费拉动的现实选择——基于税收政策效应的实证分析

消费是影响和决定国民收入的重要因素,如何实现经济增长由投资拉动向消费拉动的转变,是当前经济形势下迫切需要解决的问题。通过引入虚拟变量,从税收政策视角建立消费函数计量模型,对影响中国居民消费行为的因素进行了量化和深入分析,并基于模型的分析结果给出了政策界面。     

Continuous outcomes stochastically mismeasured as discrete random variables: a maximum likelihood approach

In an economic model of retirement behavior, a continuous dependent variable was required; the variable could only be estimated discretely with error, however. Parameter estimates using this dependent variable and ordinary least squares regression are inefficient. In th is paper, we develop a maximum likelihood procedure which adjusts for this heteroscedasticity.