Abstract. A large class of Feynman integrals, like e.g., two-point parameter integrals with at most one mass and containing local operator insertions, can be transformed to multi-sums over hypergeometric expressions. In this survey article we present a difference field approach for symbolic summation that enables one to simplify such definite nested sums to indefinite nested sums. In particular...

Model selection procedures often use a fixed penalty, such as Mallows’ Cp, to avoid choosing a model which fits a particular data set extremely well. These procedures are often devised to give an unbiased risk estimate when a particular chosen model is used to predict future responses. As a correction for not including the variability induced in model selection, generalized degrees of freedom i...

An approach for computing the correlations of species richness values obtained from nested and non-nested sampling schemes is described. The correlations obtained are used to construct species accumulation curves for the Carolina Vegetation Survey data set using the log Arrhenius, Gleason, and Arrhenius models. These models are then used to predict the richness at the 400 m2 scale, a value outs...

Conventional data models embodied by current database management systems (DBMS) do not provide satisfactory support for emerging applications. A major reason for this deficiency is the absense of concepts for complex object processing. In this paper, we explain the motivation and key properties of a new data model explicitly designed for the management of complex objects. Furthermore, the most ...

The correctness of nested transactions for multidatabases dif fers from that of at transactions in that for nested transactions the execution order of siblings at each related site should also be consistent In this paper we rst propose a simple but powerful theory for the se rializability of nested transactions in multidatabases and then a tech nique called Nested Tickets Method for Nested Tran...

Purpose This study aims to examine the ability of clean energy stocks provide cover for investors against market risks related climate change and disturbances in oil market. Design/methodology/approach The adopts feasible quasi generalized least squares technique estimate a predictive model based on Westerlund Narayan’s (2015) approach evaluating hedging effectiveness stocks. out-of-sample fore...

one of the main challenges facing the agriculture bank of iran regarding lending loans is the high probability of default by farmers. several factors could be involved in this issue and should be considered in order to control and reduce the risk in the failure of repayment. this study aimed to examine the factors affecting the repayment performance of agricultural loans in the city of maragheh...

A removahedron is a polytope obtained by deleting inequalities from the facet description of the classical permutahedron. Relevant examples range from the associahedra to the permutahedron itself, which raises the natural question to characterize which nestohedra can be realized as removahedra. In this note, we show that the nested complex of any connected building set closed under intersection...