基于旋转变压器及TMS320F28035的伺服系统位置检测

为检测伺服系统位置信息,以旋转变压器作为位置传感器,设计了基于芯片AU6802N1的位置检测电路并在此基础上提出了一种仅利用TMS320F28035对旋转变压器转子位置直接解算的方法。该方法综合运用正弦峰值采样、CLA浮点数计算、误差校正等手段。实验表明,该方法在位置解算的速度和精度上可与AU6802N1芯片相比,节约了系统成本,具有一定的实用性。     

从汉译英合句法看翻译之普遍性特征——规范化

翻译普遍性是与语言系统差异和译者个人偏好无关的翻译本身所固有的特点。翻译语料库的建立为翻译普遍性研究奠定了一定的基础。目前有关翻译普遍性的研究主要集中在简略化、明晰化和规范化等方面,而且这些特点主要体现在译文的句法层面。从合句法的翻译策略出发,对汉译英过程中涉及合句法策略的情况进行了分类和总结,详细深入地研究了翻译普遍性之一——规范化在汉译英过程中的具体体现,对进一步深刻认识汉译英的本质具有一定的指导意义。     

川东安岳方言“X到”类词语浅析

安岳方言存在大量的＂X到＂类词语。从词性看,＂X到＂类词语可作副词与动词;从句法成分看,＂X到＂类词语可在句中充当谓语和状语;从使用频率看,＂X到＂类词语涉及人们的日常生活的各个方面。＂X＋到＂类词语在安岳方言中的语义丰富,口语色彩浓厚,使用广泛。本文从句法、语义和语用价值等角度来分析安岳方言中的＂X＋到＂类词语现象。     

Semiparametric inference for survival models with step process covariates

The authors consider Bayesian methods for fitting three semiparametric survival models, incorporating time‐dependent covariates that are step functions. In particular, these are models due to Cox [Cox ( 1972 ) Journal of the Royal Statistical Society, Series B, 34, 187–208], Prentice & Kalbfleisch and Cox & Oakes [Cox & Oakes ( 1984 ) Analysis of Survival Data, Chapman and Hall, London]. The model due to Prentice & Kalbfleisch [Prentice & Kalbfleisch ( 1979 ) Biometrics, 35, 25–39], which has seen very limited use, is given particular consideration. The prior for the baseline distribution in each model is taken to be a mixture of Polya trees and posterior inference is obtained through standard Markov chain Monte Carlo methods. They demonstrate the implementation and comparison of these three models on the celebrated Stanford heart transplant data and the study of the timing of cerebral edema diagnosis during emergency room treatment of diabetic ketoacidosis in children. An important feature of their overall discussion is the comparison of semi‐parametric families, and ultimate criterion based selection of a family within the context of a given data set. The Canadian Journal of Statistics 37: 60–79; © 2009 Statistical Society of Canada     

Log‐rank permutation tests for trend: saddlepoint p‐values and survival rate confidence intervals

Suppose p + 1 experimental groups correspond to increasing dose levels of a treatment and all groups are subject to right censoring. In such instances, permutation tests for trend can be performed based on statistics derived from the weighted log‐rank class. This article uses saddlepoint methods to determine the mid‐P‐values for such permutation tests for any test statistic in the weighted log‐rank class. Permutation simulations are replaced by analytical saddlepoint computations which provide extremely accurate mid‐P‐values that are exact for most practical purposes and almost always more accurate than normal approximations. The speed of mid‐P‐value computation allows for the inversion of such tests to determine confidence intervals for the percentage increase in mean (or median) survival time per unit increase in dosage. The Canadian Journal of Statistics 37: 5‐16; 2009 © 2009 Statistical Society of Canada     

Characterizations of exponentiality within the HNBUE class and related tests

A harmonic new better than used in expectation (HNBUE) variable is a random variable which is dominated by an exponential distribution in the convex stochastic order. We use a recently obtained condition on stochastic equality under convex domination to derive characterizations of the exponential distribution and bounds for HNBUE variables based on the mean values of the order statistics of the variable. We apply the results to generate discrepancy measures to test if a random variable is exponential against the alternative that is HNBUE, but not exponential.     

Moderate deviations for parameter estimation in some time inhomogeneous diffusions

We study moderate deviations for the maximum likelihood estimation of some inhomogeneous diffusions. The moderate deviation principle with explicit rate functions is obtained. Moreover, we apply our result to the parameter estimation in α$\alpha$-Wiener bridges.     

“后人口转变论”质疑——兼与于学军、李建民博士商榷

本文就于学军、李建民博士的“后人口转变论”提出了质疑 ;对“后人口转变论”一文进行了较详细的解剖和评论。现阶段中国人口是否进入了“后时代”,“后人口转变论”是否形成了对传统人口转变论的突破和超越 ,是否建构起了新的人口理论 ,本文对此作了回答     

On the role of families and kinship networks in pre-industrial agricultural societies: An analysis of the 1698 Slavonian census

This paper uses the 1698 Slavonian census to illuminate features of social organization and productive activity of an eastern European population under the New Feudalism of the 17th century. In particular we investigate the ability of community or kinship networks to provide substitutes for missing markets in securities and production factors. It is found that kinship networks increase the efficiency of agricultural production by facilitating the exchange of oxen. This confirms contemporary reports that draft animals were the critical constraint to the expansion of agricultural output. We also find that kinship networks fail to reduce the variability of output through mutual harvest insurance. Received: 03 November 1998/Accepted: 16 June 1999     

“稻-蛙”共作生态农业模式对稻田土壤氮素的影响

通过大田试验,研究了在＂稻-蛙＂共作生态农业模式下土壤中各种形态氮素的动态变化状况.试验结果表明,施肥后土壤中各种形态氮素含量达到最大值,随着时间逐渐增加,其含量均逐渐降低.与处理CK相比,在＂稻-蛙＂共作系统中,土壤中NH＋4-N浓度显著升高,可溶性有机氮含量显著降低,而NO-3-N浓度相当.