Characterization based on convex conditional mean function

This paper addresses the problem of characterizing a distribution by means of a convex conditional mean function. The characterization is proved, under mild conditions, by means of showing the uniqueness of the solution of a certain non-linear differential equation.     

Analysis of heat wave effects on health by using generalized additive model and bootstrap-based model selection

Summary.  It is known that high summer temperature may lead to worsening health conditions among fragile individuals within exposed populations. It is also argued that multiday patterns of high temperature—heat waves—may have relevant effects on health. We discuss the possible measures of intensities of heat waves to be included in a generalized additive model explaining the number of hospital admissions that occurred during summer months in Milan. The issue of variable selection is central to the analysis: a computational method is discussed which may help in assessing the robustness of the model selection method. Eventually, we obtain evidence supporting the relevance of heat waves in driving adverse health episodes.     

Bayesian regression with multivariate linear splines

We present a Bayesian analysis of a piecewise linear model constructed by using basis functions which generalizes the univariate linear spline to higher dimensions. Prior distributions are adopted on both the number and the locations of the splines, which leads to a model averaging approach to prediction with predictive distributions that take into account model uncertainty. Conditioning on the data produces a Bayes local linear model with distributions on both predictions and local linear parameters. The method is spatially adaptive and covariate selection is achieved by using splines of lower dimension than the data.     

Two-stage time minimizing assignment problem

This paper deals with the optimal selection of m out of n facilities to first perform m   given primary jobs in Stage-I followed by the remaining (n-m)$(n-m)$ facilities performing optimally the (n-m)$(n-m)$ secondary jobs in Stage-II. It is assumed that in both the stages facilities perform in parallel. The aim of the proposed study is to find that set of m   facilities performing the primary jobs in Stage-I for which the sum of the overall completion times of jobs in Stage-I and the corresponding optimal completion time of the secondary jobs in Stage-II by the remaining (n-m)$(n-m)$ facilities is the minimum. The developed solution methodology involves solving the standard time minimizing and cost minimizing assignment problems alternately after forbidding some facility-job pairings and suggests a polynomially bound algorithm. This proposed algorithm has been implemented and tested on a variety of test problems and its performance is found to be quite satisfactory.     

非线性思维漫谈

线性思维与非线性思维是思维的两种表现形式。意识到非线性思维的存在并对它进行诠释,理清它与线性思维的不同,对非线性思维产生的生理基础,对在科学研究和文艺创作中的存在形式进行探讨,并指出了研究非线性思维的前景和意义。     

FDI对我国各地区经济增长的非线性效应分析

本文运用面板平滑转换(PSTR)模型研究国外直接投资(FDI)对我国各地区经济增长的非线性效应。选取了FDI及影响FDI的市场规模、基础设施、产业结构等8个变量作为解释变量构建单因素和多因素PSTR模型。结果表明我国经济增长与FDI之间存在着平滑转换机制效应;FDI对经济增长的影响是非线性的;FDI是我国各地区经济增长的充分条件,但不是必要条件。