A plug-in technique in nonparametric regression with dependence

The problem addressed is that of smoothing parameter selection in kernel nonparametric regression in the fixed design regression model with dependent noise. An asymptotic expression of the optimum bandwidth parameter has been obtained in recent studies, where this takes the form h = C ₀ n ^?1/5. This paper proposes to use a plug-in methodology, in order to obtain an optimum estimation of the bandwidth parameter, through preliminary estimation of the unknown value of C ₀.     

Convergence de I estimateur a noyau de derivees de Radon-Nikodym generales dans le cas melangeant

In many situations, nonparametric inference in point-process theory consists in estimating a Radon-Nikodym derivative of a nonnegative measure p with respect to another nonnegative measure v, where p and v are intensities of point processes. We consider the case of a mixing andstrictly stationary sequence of point processes and establish convergence results for the kernel estimator.     

Bias-corrected confidence bands in nonparametric regression

Bias-corrected confidence bands for general nonparametric regression models are considered. We use local polynomial fitting to construct the confidence bands and combine the cross-validation method and the plug-in method to select the bandwidths. Related asymptotic results are obtained. Our simulations show that confidence bands constructed by local polynomial fitting have much better coverage than those constructed by using the Nadaraya–Watson estimator. The results are also applicable to nonparametric autoregressive time series models.     

A bivariate distribution with Lomax and geometric margins

We develop a stochastic model describing the joint distribution of $(X,N)$, where $N$ has a geometric distribution while $X$ is the sum of $N$ dependent, heavy-tail Pareto components. Models of this form arise in many applications, ranging from hydro-climatology to finance and insurance. We present fundamental properties of this vector, including marginal and conditional distributions, moments, representations, and parameter estimation. We also include an example from finance, illustrating modeling potential of this new bivariate distribution.     

从“hold住”看网络流行语中的汉英语码混用现象

随着网络的飞速发展,网络流行语也日益丰富,不但成为网上使用的交流常用语,而且也逐渐来到网下,成为人们频繁使用的社会流行语,网络流行语的影响必将越来越大。近年来,网络流行语更是引起了语言学界的诸多关注,成为语言学家的热门研究对象。从最近流行的"hold住"一词出发,着重探讨网络流行语中的汉英语码混用现象,并通过实例分析语码混用的类型特点和现实意义。在积极肯定网络流行语作为语言形式的新发展的同时,也指出其存在的缺陷以及使用中需要注意之处。     

A new role for Low German? Language insertion as bilingual practice in the process of language shift

This article analyzes language insertion as a bilingual communicative practice, applying a functional, speaker‐focused approach to the study of sociolinguistics and language contact. The article is based on a study of contact phenomena in a formerly diglossic region in Northern Germany, where the previously spoken language – Low German – is in the process of being replaced by the dominant standard variety, German. It examines regional publications in order to establish the linguistic techniques by which Low German elements are incorporated into the Standard German texts and the communicative purposes that they serve. The paper concludes that in the process of language shift an emblematic repertoire from Low German is created which can be applied into the dominant contact language, German, for specific communicative purposes. Ausgehend von einer funktionalen, sprecherzentrierten soziolinguistischen Herangehensweise werden im folgenden Artikel bilinguale Einfügungen als Form mehrsprachiger kommunikativer Praxis untersucht. Die Studie analysiert Kontaktphänomene in einer vormals diglossischen Region Norddeutschlands, in der die gesprochene Sprache Niederdeutsch zunehmend von der dominanten Kontaktsprache Deutsch ersetzt wird. Im Artikel werden regionale Publikationen untersucht, um die sprachlichen Techniken heraus zu arbeiten, mit denen niederdeutsche Elemente in den Text integriert werden und welche kommunikativen Funktionen mit ihnen verbunden sind. Der Artikel kommt zu dem Ergebnis, dass während eines Prozesses von fortschreitendem Sprachverlust ein emblematisches niederdeutsches Repertoire geschaffen wird, das für spezifische Funktionen in die dominante Kontaktsprache Deutsch eingefügt werden kann. [Standard German] In disse Artikel geiht dat um Insprengsels van en Spraak in en anner. De Autor hett unnersöcht un lett weten, dat in Noorddüütskland as en tweetalerge Kuntrei immer mehr de sproken Spraak Nedderdüütsk van de machterge Kuntaktspraak Hoogdüütsk bisieddrückt un oflööst word. Se hett Schrifftstücken ut de Gewesten unnersöcht un deit wiesen, up wat för Maneren nedderdüütske Insprengsels in hoogdüütske Texten inbunnen worden. Daarbi kummt vandag, dat en egenaardig nedderdüütsk Weeswark upkummt, dat bi besünner Gelegenheiden in dat Hoogdüütsk sien Stee kriegen kann. [Low German]     

φ-混合序列的强大数律和收敛速度

用一般方法证明了φ-混合序列的强大数律、强收敛速度和随机变量上确界的可积性。     

Functional Estimation of a Density Under a New Weak Dependence Condition

The purpose of this paper is to prove, through the analysis of the behaviour of a standard kernel density estimator, that the notion of weak dependence defined in a previous paper (cf. Doukhan & Louhichi, 1999) has sufficiently sharp properties to be used in various situations. More precisely we investigate the asymptotics of high order losses, asymptotic distributions and uniform almost sure behaviour of kernel density estimates. We prove that they are the same as for independent samples (with some restrictions for a.s. behaviours). Recall finally that this weak dependence condition extends on the previously defined ones such as mixing, association and it allows considerations of new classes such as weak shifts processes based on independent sequences as well as some non-mixing Markov processes.     

Modified maximum likelihood estimator for the mixing distribution in a finite mixture

Using the likelihood equations, a method based on the generalized inverse of matrices is proposed to derive closed-form estimates for the mixing proportions in a finite mixture, when the component distributions are known.     

粉煤灰对高强混凝土性能的影响

在泵送混凝土中掺入适量的粉煤灰,特别是与减水剂复合使用时,不仅经济效益显著,而且能改善混凝土的性能.研究了粉煤灰高强混凝土中粉煤灰的细度、掺量对混凝土流动性、可泵性及强度的影响,最后给出了煤灰在高强混凝土中的最优掺量,可为工程应用借鉴.