Bayesian prediction of order statistics with fixed and random sample sizes based on k-record values from Pareto distribution

In this paper, the two-parameter Pareto distribution is considered and the problem of prediction of order statistics from a future sample and that of its geometric mean are discussed. The Bayesian approach is applied to construct predictors based on observed k-record values for the cases when the future sample size is fixed and when it is random. Several Bayesian prediction intervals are derived. Finally, the results of a simulation study and a numerical example are presented for illustrating all the inferential procedures developed here.     

Wiki-worthy: collective judgment of candidate notability

The use of socio-technical data to predict elections is a growing research area. We argue that election prediction research suffers from under-specified theoretical models that do not properly distinguish between ‘poll-like’ and ‘prediction market-like’ mechanisms understand findings. More specifically, we argue that, in systems with strong norms and reputational feedback mechanisms, individuals have market-like incentives to bias content creation toward candidates they expect will win. We provide evidence for the merits of this approach using the creation of Wikipedia pages for candidates in the 2010 US and UK national legislative elections. We find that Wikipedia editors are more likely to create Wikipedia pages for challengers who have a better chance of defeating their incumbent opponent and that the timing of these page creations coincides with periods when collective expectations for the candidate's success are relatively high.     

人口预测工作存在问题分析

通过探讨规划编制过程中人口预测工作的现状,指出了当前人口预测工作中存在的问题,并从指导思想、相关概念、数据来源、分析工作、预测方法等各方面分别加以分析。同时指出,规划师应当以严谨的态度去进行人口预测,才能提高规划的合理性,使得城市适应未来经济社会的飞速发展。     

基于EMD与DVG的非线性时间序列预测模型及其应用研究

针对具有非线性和不稳定性的时间序列,提出一种结合经验模态分解(EMD)、有向可见图(DVG)网络的动态预测模型。利用经验模态分解将原时间序列分解为多个固有模态函数(IMF),然后对分解后的高频和低频IMF利用快速傅里叶变换得到各自的周期;依据每个周期,从原时间序列的尾部截取长短不一的子序列,然后采用有向可见图算法转换为多个有向网络,利用随机游走在每个有向网络中寻找与时间序列最后一个节点相似的节点;最后,依据平行线法,预测时间序列的下一个数值。原油价格的时间序列是一类典型的具有非线性和不稳定性的序列,利用此模型对WTI原油每日价格进行实证分析。研究结果表明,此模型不但可以有效地预测时间序列的变化趋势,而且具有较高的预测精度。     

Conditional moving linear regression: Modeling the recruitment process for ALLHAT

Effective recruitment is a prerequisite for successful execution of a clinical trial. ALLHAT, a large hypertension treatment trial (N = 42,418), provided an opportunity to evaluate adaptive modeling of recruitment processes using conditional moving linear regression. Our statistical modeling of recruitment, comparing Brownian and fractional Brownian motion, indicates that fractional Brownian motion combined with moving linear regression is better than classic Brownian motion in terms of higher conditional probability of achieving a global recruitment goal in 4-week ahead projections. Further research is needed to evaluate how recruitment modeling can assist clinical trialists in planning and executing clinical trials.     

Prediction intervals in exponential families

A method for obtaining prediction intervals for an outcome of a future experiment is presented. The method uses hypothesis testing as a tool to derive prediction intervals and assumes that the probability distributions of informative and future experiments are one parameter exponential families. Asymptotic similar mean coverage prediction intervals are derived using the score test as a test statistics. Examples are presented and asymptotic prediction limits are compared with the prediction limits given in the literature.     

词语语义加工中N400影响因素研究述评

作为语义加工大脑指标的N400成分受多种因素的影响。研究者从词类、词频、拼写相似性、语义关联、词语具体性、语境以及词汇隐喻等方面对词语语义加工中影响N400成分的因素进行了大量的研究。然而，这些研究对词语的出现条件进行了严格的限制：对词语列表中的词语的考察脱离了语境的制约，对完形填空中词语出现概率的考察受到句法结构的制约。本文对这些影响N400成分的因素进行了评述，建议该领域的研究重点可以倾向于脱离句法结构的条件限制，考察不同结构中词语或词语组合的语义加工过程，倾向于词语语义加工的跨语言渗透，并提出在词汇学习或教学中遴选词语的策略和语境制约的作用。     

基于测井资料的低孔低渗储层产能预测研究

针对低孔低渗储层产能预测模型受敏感因素影响大，主次因素在低产情况下区别不明显，产能预测评价相对较困难等实际问题，以准噶尔盆地夏子街地区夏77井、夏79井为例，开展低孔低渗储层产能预测的前期试验研究，对多个产能预测模型及其适用条件进行了对比分析，从Darcy模型、Jones（1976）模型、Vogel/Harrison（1968）模型、裂缝模型中进行优选和调试。通过分析产能预测模型结果与测试结果在产量上的相关性，表明基于测井资料的预测结果与试油测试结果相当吻合，从而确认产能预测模型结果的可靠性。