Asymptotic distribution of martingale estimators for a class of epidemic models

This article is a contribution to the asymptotic inference on the parameters of a quite general class of stochastic models for the spread of epidemics developing in closed populations. Various epidemic models are contained within our framework, for instance, a stochastic version of the Kermack and McKendrick model and the SIS epidemic model. Each model belonging to this class, which consists in a family of discrete-time stochastic process, contains certain parameters to be estimated by means of martingale estimators. Some particular cases defined by means of Markov chains are included in our setting. The main aim of this work is to prove consistency and asymptotic normality of these estimators. Some hypothesis tests based on the main results are also shown.     

Particle predictive control

This work explores the use of sequential and batch Monte Carlo techniques to solve the nonlinear model predictive control (NMPC) problem with stochastic system dynamics and noisy state observations. This is done by treating the state inference and control optimisation problems jointly as a single artificial inference problem on an augmented state-control space. The methodology is demonstrated on the benchmark car-up-the-hill problem as well as an advanced F-16 aircraft terrain following problem.     

Nonparametric location-scale models for censored successive survival times

Let (T₁,T₂) be gap times corresponding to two consecutive events, which are observed subject to (univariate) random right-censoring. The censoring variable corresponding to the second gap time T₂ will in general depend on this gap time. Suppose the vector (T₁,T₂) satisfies the nonparametric location-scale regression model T₂=m(T₁)+σ(T₁)?, where the functions m and σ are ‘smooth’, and ? is independent of T₁. The aim of this paper is twofold. First, we propose a nonparametric estimator of the distribution of the error variable under this model. This problem differs from others considered in the recent related literature in that the censoring acts not only on the response but also on the covariate, having no obvious solution. On the basis of the idea of transfer of tail information (Van Keilegom and Akritas, 1999), we then use the proposed estimator of the error distribution to introduce nonparametric estimators for important targets such as: (a) the conditional distribution of T₂ given T₁; (b) the bivariate distribution of the gap times; and (c) the so-called transition probabilities. The asymptotic properties of these estimators are obtained. We also illustrate through simulations, that the new estimators based on the location-scale model may behave much better than existing ones.     

Dynamic survival models with spatial frailty

In many survival studies, covariates effects are time-varying and there is presence of spatial effects. Dynamic models can be used to cope with the variations of the effects and spatial components are introduced to handle spatial variation. This paper proposes a methodology to simultaneously introduce these components into the model. A number of specifications for the spatial components are considered. Estimation is performed via a Bayesian approach through Markov chain Monte Carlo methods. Models are compared to assess relevance of their components. Analysis of a real data set is performed, showing the relevance of both time-varying covariate effects and spatial components. Extensions to the methodology are proposed along with concluding remarks.     

论“宁波帮”精神财富的巨大意义

邓小平同志20年前发表的关于"宁波帮"的重要指示,既是对"宁波帮"支援家乡现代化建设的伟大号召,同时还包含着更深刻的内容"宁波帮"在经济建设方面的丰富经验,对于市场经济规律的熟悉,以及由此体现出来的深厚的人文精神的积淀.认真继承发扬他们的精神财富,对于进一步理解和落实科学发展观,加快宁波的社会主义建设,具有十分重要的意义.     

高师体育教学改革的对策

本文对深化高师体育教育教学改革,优化课程结构和教学过程,全面推进素质教育的策略与对策,进行了全面阐述,对推动高师体育教育教学改革、全面推进素质教育工作具有指导作用.     

日语的“时”的语法范畴

“时”是重要的语法范畴之一。传统的日本学校语法只是研究助动词た ,有其不科学性的表现。尤其是相对时间的研究和从句时间的研究还很不彻底。从不同的语言环境 ,即句子的不同类型着眼来分析日语的时间表现 ,不失为新的研究方式之一。     

与时俱进开拓创新努力做好新时期关心下一代工作

在学校党委的领导下,发挥离退休老同志的育人作用,做好青年学生的思想政治工作,全面提高综合素质,是高校关心下一代工作的重要内容。文章就发挥好离退休人员的育人职能、加强自身建设、探索有效载体等方面,阐述了新时期,如何做好高校关心下一代工作。