Search results for "error"
showing 10 items of 1643 documents
Bayesian PDF reweighting meets the Hessian methods
2016
Volume: 273 New data coming from the LHC experiments have a potential to extend the current knowledge of parton distribution functions (PDFs). As a short cut to the cumbersome and time consuming task of performing a new PDF fit, re weighting methods have been proposed. In this talk, we introduce the so-called Hessian re-weighting, valid for PDF fits that carried out a Hessian error analysis, and compare it with the better-known Bayesian methods. We determine the existence of an agreement between the two approaches, and illustrate this using the inclusive jet production at the LHC. Peer reviewed
PDF reweighting in the Hessian matrix approach
2014
We introduce the Hessian reweighting of parton distribution functions (PDFs). Similarly to the better-known Bayesian methods, its purpose is to address the compatibility of new data and the quantitative modifications they induce within an existing set of PDFs. By construction, the method discussed here applies to the PDF fits that carried out a Hessian error analysis using a non-zero tolerance $\Delta\chi^2$. The principle is validated by considering a simple, transparent example. We are also able to establish an agreement with the Bayesian technique provided that the tolerance criterion is appropriately accounted for and that a purely exponential Bayesian likelihood is assumed. As a practi…
Experimental Sentinel-2 LAI estimation using parametric, non-parametric and physical retrieval methods – A comparison
2015
Abstract Given the forthcoming availability of Sentinel-2 (S2) images, this paper provides a systematic comparison of retrieval accuracy and processing speed of a multitude of parametric, non-parametric and physically-based retrieval methods using simulated S2 data. An experimental field dataset (SPARC), collected at the agricultural site of Barrax (Spain), was used to evaluate different retrieval methods on their ability to estimate leaf area index (LAI). With regard to parametric methods, all possible band combinations for several two-band and three-band index formulations and a linear regression fitting function have been evaluated. From a set of over ten thousand indices evaluated, the …
A heuristic model-based approach for compensating wind effects in ski jumping.
2021
Wind influences the jump length in ski jumping, which raises questions about the fairness. To counteract the wind problem, the International Ski Federation has introduced a wind compensation system in 2009: time-averaged wind velocity components tangential to the landing slope are obtained from several sites along the landing slope, and these data are used in a linear statistical model for estimating the jump length effect of wind. This is considered in the total score of the ski jump. However, it has been shown that the jump length effect estimates can be inaccurate and misleading. The present manuscript introduces an alternative mathematical wind compensation approach that is based on an …
Entanglement in continuous-variable systems: recent advances and current perspectives
2007
We review the theory of continuous-variable entanglement with special emphasis on foundational aspects, conceptual structures, and mathematical methods. Much attention is devoted to the discussion of separability criteria and entanglement properties of Gaussian states, for their great practical relevance in applications to quantum optics and quantum information, as well as for the very clean framework that they allow for the study of the structure of nonlocal correlations. We give a self-contained introduction to phase-space and symplectic methods in the study of Gaussian states of infinite-dimensional bosonic systems. We review the most important results on the separability and distillabil…
Multi-boson block factorization of fermions
2017
The numerical computations of many quantities of theoretical and phenomenological interest are plagued by statistical errors which increase exponentially with the distance of the sources in the relevant correlators. Notable examples are baryon masses and matrix elements, the hadronic vacuum polarization and the light-by-light scattering contributions to the muon g-2, and the form factors of semileptonic B decays. Reliable and precise determinations of these quantities are very difficult if not impractical with state-of-the-art standard Monte Carlo integration schemes. I will review a recent proposal for factorizing the fermion determinant in lattice QCD that leads to a local action in the g…
CHEESE HARDNESS ASSESSMENT BY EXPERTS AND UNTRAINED JUDGES
2001
Although expert assessment of food characteristics is recognized as a key step in product development, the use of consumer based measurements is sometimes recommended as an equivalent to the experts. From cognitive psychology, support of the role of perceptual learning is found in some instances, although this could not be relevant in others. To address this point performance analysis of experts and untrained panelists in cheese texture evaluation was carried out. Neither the untrained panelists nor the experts were familiar with either the scales or the kind of cheese. The same Cheddar cheese was given to 44 untrained subjects in three trials to assess hardness. The results showed that the…
The Holocaust and the birth of Israel in British, Swedish and Finnish press discourse, 1947–1948
2009
This article examines the way in which the Holocaust was linked to the process of the birth of Israel between 1947 and 1948 in the mainstream British, Swedish and Finnish press. By utilising a framework of comparative cultural history, this essay seeks to understand why different countries responded to the suffering of the Jews during the Second World War in such diverse ways. This essay also seeks to question the popular belief that the two events were intimately linked, and that the link was recognised in a straightforward manner. Hence, the study argues that although the press coverage sometimes managed to establish the connection between the two events, more typically the news was domes…
Terrorist Masculinities: Political Masculinity between Fiction, Facts, and Their Mediation
2018
This essay proposes that terrorism manifests itself in a relation that encompasses masculinity as well as the media. The origin of this relationship is the joint performativity of gender and acts of terror. This makes terrorism an instrument of social and political change. But in order to legitimize themselves, terrorism as well as masculinity require authorization by a phantasmagorical power. Drawing on the dominance of males among terrorists, this essay will look at an early depiction of terrorism in Conrad’s The Secret Agent, a contemporary representation in Sahota’s novel Ours Are the Streets and terrorism’s real manifestation in the Paris carnage of November 2015. It will show that in…
Errors d?edició : dels manuscrits als diccionaris. Exemples de textos mèdics medievals (Hipòcrates, Arnau de Vilanova, Bernat de Gordon, misser Joan)
2017
The commonly used Catalan lexicons (DCVB, DECLC, the vocabulary of Lluis Faraudo de Saint-Germain) collect words and give them meaning from ancient editions of texts. Lexicographers’ performance had its own logic: they used the documentary sources they had at their disposal when they set up to write their works. The advances in philological research (new critical editions, new sources of information) allow us to refine results and detect errors that occurred in old editions and went into dictionaries. Wrong lexemes were included, as well as incorrect or insufficient definitions. This article offers examples of it, out of four medical works. On the one hand, the Catalan translations of the R…