Search results for " Opera"

Non-perturbative renormalisation of left left four-fermion operators with Neuberger fermions

2006

We outline a general strategy for the non-perturbative renormalisation of composite operators in discretisations based on Neuberger fermions, via a matching to results obtained with Wilson-type fermions. As an application, we consider the renormalisation of the four-quark operators entering the Delta S=1 and Delta S=2 effective Hamiltonians. Our results are an essential ingredient for the determination of the low-energy constants governing non-leptonic kaon decays.

Radiative decays in charmonium beyond the p/m approximation

2020

We analyze the theoretical description of radiative decays in charmonium. We use an elementary emission decay model to build the most general electromagnetic transition operator. We show that accurate results for the widths can be obtained from a simple quark potential model reasonably fitting the spectroscopy if the complete form of the operator is used instead of its standard p/m approximation and the experimental masses are properly implemented in the calculation.

Representations and derivations of quasi ∗-algebras induced by local modifications of states

2009

Abstract The relationship between the GNS representations associated to states on a quasi ∗-algebra, which are local modifications of each other (in a sense which we will discuss) is examined. The role of local modifications on the spatiality of the corresponding induced derivations describing the dynamics of a given quantum system with infinite degrees of freedom is discussed.

A quasiconformal composition problem for the Q-spaces

2017

Given a quasiconformal mapping $f:\mathbb R^n\to\mathbb R^n$ with $n\ge2$, we show that (un-)boundedness of the composition operator ${\bf C}_f$ on the spaces $Q_{\alpha}(\mathbb R^n)$ depends on the index $\alpha$ and the degeneracy set of the Jacobian $J_f$. We establish sharp results in terms of the index $\alpha$ and the local/global self-similar Minkowski dimension of the degeneracy set of $J_f$. This gives a solution to [Problem 8.4, 3] and also reveals a completely new phenomenon, which is totally different from the known results for Sobolev, BMO, Triebel-Lizorkin and Besov spaces. Consequently, Tukia-V\"ais\"al\"a's quasiconformal extension $f:\mathbb R^n\to\mathbb R^n$ of an arbitr…

A prospective study on an innovative online forum for peer reviewing of surgical science

2017

Background Peer review is important to the scientific process. However, the present system has been criticised and accused of bias, lack of transparency, failure to detect significant breakthrough and error. At the British Journal of Surgery (BJS), after surveying authors' and reviewers' opinions on peer review, we piloted an open online forum with the aim of improving the peer review process. Methods In December 2014, a web-based survey assessing attitudes towards open online review was sent to reviewers with a BJS account in Scholar One. From April to June 2015, authors were invited to allow their manuscripts to undergo online peer review in addition to the standard peer review process. T…

How to Become a Pediatric Surgeon?

2020

As the title of this chapter already suggests, in this chapter the path of how become a pediatric surgeon is described and important question on this issue are answered. These questions are all dealing with the process and the structure of pediatric surgery training and the requirements which are necessary to become a pediatric surgeon. In preparation of this book chapter, we performed an online survey about the organization and structure of pediatric surgery training around the world. The survey was sent to all official national admissions departments and organizations of pediatric surgery. Thus, data from 28 different countries were compiled. They serve as the basis of some of the questio…

Statistical performance of a multiclass bulk production queueing system

2004

Abstract In this paper, we discuss how to statistically analyze a make-to-stock production system the behaviour of which depends on a multiclass bulk queueing system. The performance of the system is evaluated in terms of the different demands of products, processing times and, mainly, through the finished product inventory and other related measures that quantify the queueing effects in the system. A numerical example which illustrates the applicability of the results in an inventory scenario is also discussed.

Implementation of Universal Digital Architecture using 3D-NoC for Mobile Terminal

2014

International Conference on Control, Decision and Information Technologies (CoDIT), Ecole Natl Ingenieurs Metz, Metz, FRANCE, NOV 03-05, 2014; International audience; The need to integrate multiple wireless communication protocols into a single low-cost flexible hardware platform is prompted by the increasing number of emerging communication protocols and applications in modern embedded systems. So the current challenge is to design of new digital architectures, in addition to its ability to take over of many functions. In this paper we have identified similarities between the despreader units in Rake receiver and the processor element in FFT-SDF (Fast Fourier Transform-Single path Delay Fe…

Eigenvectors of k–ψ-contractive wedge operators

AbstractWe present new boundary conditions under which the fixed point index of a strict-ψ-contractive wedge operator is zero. Then we investigate eigenvalues and corresponding eigenvectors of k–ψ-contractive wedge operators.

Temperature-dependent angular resolved UV-photoemission spectroscopy from CeNi2Ge2

2001

Abstract Pronounced temperature effects in angular resolved ultraviolet photoelectron spectroscopy from the (001) surface of the ternary heavy fermion compound CeNi 2 Ge 2 are presented. The measurements were performed on atomically clean and well-ordered thin films grown on a W(110) substrate. A strongly enhanced intensity at the Fermi edge ( ϵ F ) is observed at low-temperatures if the spectra are excited by means of HeI light ( hν =21.2 eV). In addition, the work function is dramatically increased with temperature, exhibiting an unusually high positive temperature coefficient of about 0.65 meV/K. The observed temperature dependency suggests a strong redistribution of the states near the …