We consider approximations of a smooth convex body by inscribed and circumscribed convex polytopes as the number of vertices, resp. facets tends to innnity. The measure of deviation used is the diierence of the mean width of the convex body and the approximating polytopes. The following results are obtained. (i) An asymptotic formula for best approximation. (ii) Upper and lower estimates for st...

The eYcacy of individual components of an online course on positive course outcome was examined via stepwise multiple regression analysis. Outcome was measured as the student’s total score on all exams given during the course. The predictors were page hits, discussion posts, and discussion reads. The vast majority of the variance of outcome was accounted for by total page hits. Participation in...

Inflation risk is of high relevance in non-life insurers’ long-tail business and can have a major impact on claims reserving. In this paper, we empirically study claims inflation with focus on automobile liability insurance based on a data set provided by a large German non-life insurance company. The aim is to obtain empirical insight regarding the drivers of claims inflation risk and its impa...

We illustrate how a comparatively new technique, a Tabu search variable selection model [Drezner, Marcoulides and Salhi (1999)], can be applied efficiently within finance when the researcher must select a subset of variables from among the whole set of explanatory variables under consideration. Several types of problems in finance, including corporate and personal bankruptcy prediction, mortgag...

This study identifies and assesses the controls on hydraulic erosion of cohesive riverbanks on a 600-m reach of an urban ephemeral stream with active bank erosion. We examined hydraulic bank erosion by separating estimated bank shear stress into four properties: magnitude, duration, event peak, and variability. The values of these independent variables were used as a bank erosion context at thr...

Fast Parallel Kriging-Based Stepwise Uncertainty Reduction With Application to the Identification of an Excursion Set Clément Chevalier, David Ginsbourger, Julien Bect, Emmanuel Vazquez, Victor Picheny & Yann Richet a Institute of Mathematical Statistics and Actuarial Science University of Bern CH-3012 Bern, Switzerland (; ) b Department of Signal Processing & Electronic Systems Supelec, Gif-su...

To safely evolve a software product line, it is important to have a notion of product line refinement that assures behavior preservation of the original product line products. So in this article we present a language independent theory of product line refinement, establishing refinement properties that justify stepwise and compositional product line evolution.Moreover, we instantiate our theory...

The stepwise hydrogenation of the C=C bond and C=O group of acrolein on Au3 and Au5 model systems is investigated using the density functional theory(DFT) PW91 functional. Our results show that the C=C hydrogenation is more favorable than that of C=O bond on Au3 with the barriers of the rate-determining step being 0.35 and 0.62 eV respectively. On the other hand, the C=O reduction is preferred ...

From winter 2009 to spring 2010, due to decreasing precipitation and high temperature, Southwest China experienced the worst meteorological drought in 60 years. The drought has impacted large areas of Guizhou, Yunnan, Guangxi and Sichuan provinces. In this paper, climate data (precipitation and temperature) and SPOT VGT Normalized Difference Vegetation Index (NDVI) data were combined with land ...

Transition systems are a basic semantic model for formal description , speciication, and analysis of concurrent and distributed systems. In order to describe and analyze aspects of reliability, such as the likelihood of trace and failure, this model has been extended in various ways to handle probabilistic behavior. To use these models for specii-cation and stepwise development of systems, it i...