Non-parametric estimation of the long-range dependence exponent for Gaussian processes

We consider a class of long-range-dependent Gaussian processes defined in a semiparametric framework. We propose a new estimator of the long-range dependence parameter, based on the integration of the periodogram in two windows. We show that it is asymptotically Gaussian and calculate the rate of convergence. We optimise parameters defining the window function for the minimum mean-square-error criterion. In a Monte-Carlo study, we compare the proposed estimator with previously studied estimators.     

论我国货币政策传导机制中的障碍

通过对近年来我国出现的通货紧缩现象的分析 ,可以看到中央银行所采取的稳健的货币政策的内容及其执行状况。经济的不景气不是由于货币供应量不足而是在于货币政策的传导机制的不畅。我们应找出传导机制不畅的原因 ,并提出相应的对策     

用PowerPoint设计MCAI课件

通过分析各种课件开发工具的特点,介绍了使用PowerPoint制作课件的一般过程.从课件模板、模型的选择和课件内容的设计、创意的实现等四个方面进行了阐述,并具体给出了几个制作技巧.     

我国丝绸出口贸易的经济分析

我国丝绸出口贸易的 "显示"比较优势指数呈逐年下降的趋势,但其数值一直保持在17以上,说明我国的丝绸出口与其他出口商品相比仍具有很大的竞争优势;我国丝绸出口的相对价格弹性系数为-0.3825,属于低弹性的商品.降低丝绸出口价格,不但无益于丝绸出口量的增加,反而会引起出口创汇额的明显下降,引起丝绸"出口贫困"现象的产生.稳定我国丝绸出口价格,是我国蚕丝业和丝绸贸易稳定发展的正确选择.     

Regularization with Maximum Entropy and Quantum Electrodynamics: The Merg(E) Estimators

It is well-known that under fairly conditions linear regression becomes a powerful statistical tool. In practice, however, some of these conditions are usually not satisfied and regression models become ill-posed, implying that the application of traditional estimation methods may lead to non-unique or highly unstable solutions. Addressing this issue, in this paper a new class of maximum entropy estimators suitable for dealing with ill-posed models, namely for the estimation of regression models with small samples sizes affected by collinearity and outliers, is introduced. The performance of the new estimators is illustrated through several simulation studies.     

Dopamine Genes and Pathological Gambling in Discordant Sib-Pairs

Pathological gambling (PG) is an impulse control disorder that has been considered as a behavioral addiction. Recent studies have suggested the involvement of the dopaminergic system in addictions and impulse control disorders and associations of dopamine receptor genes (DRD1, DRD2, and DRD4) and PG have been reported. In the present study, 140 sib-pairs discordant for the diagnosis of PG (70 males and 70 females on each group) were recruited through the Gambling Outpatient Unit at the Institute of Psychiatry, University of Sao Paulo and were assessed by trained psychiatrists. A family-based association design was chosen to prevent population stratification. All subjects were genotyped for dopamine receptor genes (DRD1 -800 T/C, DRD2 TaqIA RFLP, DRD3 Ser9Gly, DRD4 48bp exon III VNTR, DRD5 (CA) repeat) and the dopamine transporter gene (SCL6A3 40 bp VNTR). Our results suggest the association of PG with DRD1 -800 T/C allele T (P = .03).     

Gender differences in the relationship between intimate partner violence victimization and the perception of dating situations among college students

Although the prevalence and severity of dating violence among college students is well known, the relationship between past victimization and perceptions of future dating situations has not been examined. Using both qualitative and quantitative research methods, this study investigated gender differences in the relationship between intimate partner violence victimization and the perceptions of dating situations. The study found that the more psychological, physical, or sexual violence that was experienced by females, the more likely they perceived dating situations as inappropriate. Males, on the other hand, were more likely to report aggressive behaviors in dating situations only if victimized by sexual violence. Implications for professionals working with college students or community prevention programs are discussed.     

Rurality and Income Inequality in the United States, 1975–2015

Recent events have focused attention on the perceived widening of the economic divide between urban and rural areas, and on the continued rise of national income inequality. We demonstrate that, in fact, the average income gap between urban (metropolitan) and rural (nonmetropolitan) households has not risen over the past 40 years, and makes virtually no contribution to national income inequality. Rising national inequality is driven by rising inequality within both urban and rural America, not by an urban/rural divergence. As is well known, the growing dispersion of household money income is partly driven by rising wage inequality, particularly in urban areas. Less well recognized is the role played by other income sources. We show that a decline in the progressivity of the distribution of social security payments and cash transfers, and an increase in the regressivity of the distribution of retirement incomes, have jointly made a comparably large contribution to rising income inequality. At the same time, the share of income from self-employment has declined, particularly in rural America, and because self-employment income is very unequally distributed, its diminution has retarded the growth of rural inequality. In 2014–15, however, rural inequality increased, cutting the urban/rural inequality gap in half.     

Changement technologique et emploi au Brésil,en Colombie et au Mexique: quels sont les travailleurs les plus affectés?

L'analyse, axée sur les tâches, de la structure de l'emploi urbain du Brésil, de la Colombie et du Mexique montre que celui-ci a nettement diminué entre 2002 et 2015 dans des professions semi-qualifiées et augmenté dans les professions faiblement et fortement qualifiées. La décomposition des résultats suggère que le déclin de l'emploi des secrétaires et des sténographes s'explique entièrement par les changements intrabranche (hypothèse de «routinisation»), tandis que dans la conduite des machines et l'artisanat l'explication tient aux changements interbranches. Sous l'angle sociodémographique, le changement technologique affecte négativement les femmes, mais il profite aux travailleurs plus jeunes et plus instruits.