We discuss various higher-order discretization methods for diffusion terms in residual-distribution methods. Categorizing methods into two types: node-based (Galerkin methods) and cell-based (residual-distribution methods), we begin with the description of the basic low-order methods. We then consider two different approaches to extend these methods to higher-order: reconstruction and higher-or...

In this work we analyze and compare two recent variational models for image denoising and improve their reconstructions by applying a Bregman iteration strategy. One of the standard techniques in image denoising, the ROF-model (cf. Rudin et al. in Physica D 60:259–268, 1992), is well known for recovering sharp edges of a signal or image, but also for producing staircase-like artifacts. In order...

This work shows how the probability density function (PDF) of the turbulent velocity fluctuation can be estimated from the deconvolution of ensemble averaged cross-correlation and auto-correlation functions of PIV recordings. Once the PDF is known, the mean displacement, the Reynolds stresses as well as higher order moments can reliable be estimated. The approach was tested on synthetic PIV ima...

Many researches attempt to improve the efficiency of the usual quasi-Newton (QN) methods by accelerating the performance of the algorithm without causing more storage demand. They aim to employ more available information from the function values and gradient to approximate the curvature of the objective function. In this paper we derive a new QN method of this type using a fourth order tensor m...

Soundness and adequacy theorems are presented for the expressive power of higher-order initial algebra specifications with respect to the arithmetical and analytical hierarchies. These results demonstrate that higher-order initial algebra semantics substantially extends the power of both first-order initial and first-order final algebra semantics. It thus provides a unifying framework for all t...

The determination of the mean survival time t ~i.e., inverse reaction rate! associated with diffusion-controlled reactions among static traps is a problem of long-standing interest, dating back to the classical work of Smoluchkowski. For the broad class of model particulateand digitized-based models considered here, we find a universal curve for the mean survival time t for a wide range of poro...

For at least partially ordered three-way tables, it is well known how to arithmetically decompose Pearson’s X2 P statistic into informative components that enable a close scrutiny of the data. Similarly well-known are smooth models for two-way tables from which score tests for homogeneity and independence can be derived. From these models, both the components of Pearson’s X2 P and information a...

We analyze the general structure of soft scalar masses emerging in superstring models involving anomalous U(1) symmetries, with the aim of characterizing more systematically the circumstances under which they can happen to be flavor universal. We consider both heterotic orbifold and intersecting brane models, possibly with several anomalous and non-anomalous spontaneously broken U(1) symmetries...

Previously, the weight parameter of the finite mixture of regression models has been assumed to be invariant of the characteristics of the observations under study. Recently, it has been shown that the weight parameter of the finite mixture of negative binomial (NB) models can be dependent upon the attributes of the sites. Since the selection of the functional form for weight parameter has a si...