Search results for "Smooth"
showing 10 items of 710 documents
Exploiting Numerical Behaviors in SPH.
2010
Smoothed Particle Hydrodynamics is a meshless particle method able to evaluate unknown field functions and relative differential operators. This evaluation is done by performing an integral representation based on a suitable smoothing kernel function which, in the discrete formulation, involves a set of particles scattered in the problem domain. Two fundamental aspects strongly characterizing the development of the method are the smoothing kernel function and the particle distribution. Their choice could lead to the so-called particle inconsistency problem causing a loose of accuracy in the approximation; several corrective strategies can be adopted to overcome this problem. This paper focu…
The effects of metoclopramide on acetylcholine release and on smooth muscle response in the isolated guinea-pig ileum
1982
The effects of metoclopramide on smooth muscle contraction and on release of acetylcholine were studied in the guinea-pig myenteric plexus longitudinal muscle preparation. Acetylcholine was determined either as endogenous acetylcholine, or as labelled transmitter from strips preloaded with 3H-choline. Metoclopramide caused an increase in resting tension of longitudinal muscle as well as an increase in resting output of either endogenous or labelled acetylcholine. Tetrodotoxin abolished the metoclopramide-evoked increase in transmitter release. The increase in smooth muscle tension was clearly related to the increase in resting output. The effects of metoclopramide on both longitudinal muscl…
An order-adaptive compact approximation Taylor method for systems of conservation laws
2021
Abstract We present a new family of high-order shock-capturing finite difference numerical methods for systems of conservation laws. These methods, called Adaptive Compact Approximation Taylor (ACAT) schemes, use centered ( 2 p + 1 ) -point stencils, where p may take values in { 1 , 2 , … , P } according to a new family of smoothness indicators in the stencils. The methods are based on a combination of a robust first order scheme and the Compact Approximate Taylor (CAT) methods of order 2p-order, p = 1 , 2 , … , P so that they are first order accurate near discontinuities and have order 2p in smooth regions, where ( 2 p + 1 ) is the size of the biggest stencil in which large gradients are n…
The appraisal smoothing in the real estate indeces
2013
The appraisal smoothing is the phenomenon in which the valuation of a property, based on the judgments of appraisers (expertise) rather than on the collection of market data, is influenced by previous valuations performed by the same expert. The most obvious consequence of the exercise of expertise is the tendency to generate in the time a smoothing in the estimated value. This is the first experimental application of the appraisal smoothing theory in Italy. The general spread of real estate valuations, based on prices and average prices refer to a single commercial parameter (usually the surface), generates the natural suspicion that the smoothing effect could be widely disseminated and th…
Some Numerical Remarks on a Meshless Approximation Method
2016
In this paper we consider sources of enhancement for the Smoothed Particle Hydrodynamics method in approximating a function and its derivatives. It is well known that the standard formulation is usually poor when scattered data distribution is considered or when the approximation near the boundary occurs. In this paper studies on the accuracy are provided and assessed with gridded and scattered data distribution in the problem domain. The improvements of the method are addressed and supporting numerical experiments are included.
Color Correction for Image Stitching by Monotone Cubic Spline Interpolation
2015
This paper proposes a novel color correction scheme for image stitching where the color map transfer is modelled by a monotone Hermite cubic spline and smoothly propagated into the target image. A three-segments monotone cubic spline minimizing color distribution statistics and gradient differences with respect to both the source and target images is used. While the spline model can handle non-linear color maps, the minimization over the gradient differences limits strong alterations on the image structure. Adaptive heuristics are introduced to reduce the minimization search space and thus computational time. Experimental comparisons with respect to the state-of-the-art linear mapping model…
Noise Filtering Using Edge-Driven Adaptive Anisotropic Diffusion
2008
This paper presents a method aimed to noise removal in MRI (Magnetic Resonance Imaging). We propose an improvement of Perona and Malik's anisotropic diffusion filter. In our schema, the diffusion equation of the filter has been modified to take into account the edges direction, This allows the filter to blur uniform areas, while it better preserves the edges. Both quantitative and qualitative evaluation is presented and the results are compared with other methods.