略论虞翻易学

作为东汉三国时期的易学大家,虞翻承于荀爽的传统,以卦变说解《易》,其中蕴含着阴阳变易的辩证思想,而且取代了京房、《易纬》的阴阳灾异之说。除卦变说外,之正说、旁通说、互体说、半象说、卦气说、纳甲说、反对说、成既济定说等共同构成了虞翻易学的象数易学体系。这个体系是在吸收以往成果基础上的集大成总结和发展,对后世易学产生了很大的影响。虞翻易学在一定程度上使得象数形式与义理内容的矛盾更加激化,将象数易学引向了极其复杂的道路,但在其体系中又可见以道家思想解《易》的基本走势,并在客观上启发了王弼易学。     

油气田边远地区天然气资源的综合利用研究

油气田边远地区天然气资源包括油田放空天然气(主要是油田伴生气)和低产气井天然气,它们均因气量小,就地无用户和远离输气管网等原因长期未得到开发利用,不仅极大地浪费了资源,而且严重地污染了油田地区的大气。综述了国内外可用于油气田边远地区天然气资源开发利用的净化技术和综合利用技术,认为利用这部分天然气资源应依据气质、气量和市场需求选用合理的净化技术及利用技术,最后对吐哈油田边远地区天然气资源的综合利用进行了研究。     

音乐形态、写作方式与词体的定型——兼及李白《菩萨蛮》辨伪

词律的起源是词体发生问题的核心与重点。还原词发生初期词乐配合的原初状态,可发现“词的文本形态来源于音乐形态”这一传统观点有失允当。词的写作方式有依乐填辞、依辞写辞两种,这不但是乐工辞与文人辞的分野,也代表了词体发展的两个阶段。词获得稳定的文体形态是在文人辞阶段,高度趋向一致的词律是在文人的重复性、摹拟性写作中形成的,在这一过程中,文人的群体活动、知识结构起到了关键性作用。循此思路,结合唐宋间韵部分合、相叶的特点,说明《菩萨蛮》（平林漠漠烟如织）非李白作品,其制辞时代为宋代。     

Evaluating the Use of Spatial Covariance Structures in the Analysis of Cardiovascular Imaging Data

This article investigates the choice of working covariance structures in the analysis of spatially correlated observations motivated by cardiac imaging data. Through Monte Carlo simulations, we found that the choice of covariance structure affects the efficiency of the estimator and power of the test. Choosing the popular unstructured working covariance structure results in an over-inflated Type I error possibly due to a sample size not large enough relative to the number of parameters being estimated. With regard to model fit indices, Bayesian Information Criterion outperforms Akaike Information Criterion in choosing the correct covariance structure used to generate data.     

Robust Smoothed Rank Estimation Methods for Accelerated Failure Time Model Allowing Clusters

Smoothed Gehan rank estimation methods are widely used in accelerated failure time (AFT) models with/without clusters. However, most methods are sensitive to outliers in the covariates. In order to solve this problem, we propose robust approaches based on the smoothed Gehan rank estimation methods for the AFT model, allowing for clusters by employing two different weight functions. Simulation studies show that the proposed methods outperform existing smoothed rank estimation methods regarding their biases and standard deviations when there are outliers in the covariates. The proposed methods are also applied to a real dataset from the “Major cardiovascular interventions” study.     

Intraday Serial Correlation,Volatility, and Jump: Evidence from China's Stock Market

In this article, we investigate the relationships among intraday serial correlation, jump-robust volatility, positive and negative jumps based on Shanghai composite index high frequency data. We implement variance ratio test to quantify intraday serial correlation. We also measure the continuous part of realized volatility using jump-robust MedRV estimator and disentangle positive and negative jumps using Realized Downside Risk Measure and Realized Upside Potential Measure proposed by Bi et al., (2013 Bi, T., Zhang, B., Wu, H. (2013). Measuring downside risk using high frequency data–realized downside risk measure. Communications in Statistics–Simulation and Computation 42(4):741–754.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). We find that intraday serial correlation are positively correlated with jump-robust volatility and negatively correlated with negative jumps which confirm the LeBaron effect.     

Symmetrical Design of Experiment in Global Sensitivity Analysis Based on ANOVA High-dimensional Model Representation

This article reviews symmetrical global sensitivity analysis based on the analysis of variance of high-dimensional model representation. To overcome the computational difficulties and explore the use of symmetrical design of experiment (SDOE), two methods are presented. If the form of the objective function f is known, we use SDOE to estimate the symmetrical global sensitivity indices instead of Monte Carlo or quasi-Monte Carlo simulation. Otherwise, we use the observed values of the experiment to do symmetrical global sensitivity analysis. These methods are easy to implement and can reduce the computational cost. An example is given by symmetrical design of experiment.     

A Seemingly Unrelated Nonparametric Additive Model with Autoregressive Errors

This article considers a nonparametric additive seemingly unrelated regression model with autoregressive errors, and develops estimation and inference procedures for this model. Our proposed method first estimates the unknown functions by combining polynomial spline series approximations with least squares, and then uses the fitted residuals together with the smoothly clipped absolute deviation (SCAD) penalty to identify the error structure and estimate the unknown autoregressive coefficients. Based on the polynomial spline series estimator and the fitted error structure, a two-stage local polynomial improved estimator for the unknown functions of the mean is further developed. Our procedure applies a prewhitening transformation of the dependent variable, and also takes into account the contemporaneous correlations across equations. We show that the resulting estimator possesses an oracle property, and is asymptotically more efficient than estimators that neglect the autocorrelation and/or contemporaneous correlations of errors. We investigate the small sample properties of the proposed procedure in a simulation study.     

大班额下幼儿园集体教学活动的优化

目前大班额已经成为我国基础教育十分普遍的现象。而幼儿园的大班额集体教学活动存在诸多问题,如教师占主导地位,与幼儿交流较少;投放材料不充足,活动开展容易受限;活动缺乏客观评价,教育效果不明显。针对上述问题,提出了具体的优化措施,以促进幼儿的身心发展。