Search results for " Normal"
showing 10 items of 336 documents
Concrete thermal energy storage for linear Fresnel collectors: Exploiting the South Mediterranean’s solar potential for agri-food processes
2018
Abstract Italy is celebrated in the world for its agri-food industries while the process of production of pasta is highly energy demanding and requires both electrical and thermal energy simultaneously. Because most of the Italian factories producing pasta are located in the Southern part of the country, the direct use of thermal energy generated from the sun would be particularly profitable. In this study, the authors examine the possibility of generating by a Solar Industrial Process Heating plant the thermal energy required annually by an existing factory that produces durum wheat pasta located in Sicily (Italy). The hypothesized plant scheme consists of an array of Fresnel linear solar …
Non-Gaussian Distribution for Var Calculation
2003
Publisher Summary This chapter compares different approaches to computing Value-at-Risk (VaR) for heavy tailed return series. Each model has been submitted to a backtest analysis. The most representative asset returns of the Italian stock market and the exchange rates for the major currencies are used. The results obtained confirm that when the percentiles are below 5%, the hypothesis of normality of the conditional return distribution determines intervals of confidence whose forecast ability is low. In fact, it is observed that the return distributions are asymmetric and leptokurtic and the hypothesis of normality is usually rejected when subject to statistical test. Among the alternative …
Self-normalized and randomly centered spectral estimates
1996
We review some limit theory for the periodogram and for integrated versions of it and explain the use of random normalizing and centering techniques.
Two-stage adaptive designs with correlated test statistics.
2005
When performing a trial using an adaptive sequential design, it is usually assumed that the data for each stage come from different units; for example, patients. However, sometimes it is not possible to satisfy this condition or to check whether it is satisfied. In these cases, the test statistics and p-values of each stage may be dependent. In this paper we investigate the type I error of two-stage adaptive designs when the test statistics from the stages are assumed to be bivariate normal. Analytical considerations are performed under the restriction that the conditional error function is constant in the continuation region. We show that the decisions can become conservative as well as an…
Genetic Normalized Convolution
2011
Normalized convolution techniques operate on very few samples of a given digital signal and add missing information, trough spatial interpolation. From a practical viewpoint, they make use of data really available and approximate the assumed values of the missing information. The quality of the final result is generally better than that obtained by traditional filling methods as, for example, bilinear or bicubic interpolations. Usually, the position of the samples is assumed to be random and due to transmission errors of the signal. Vice versa, we want to apply normalized convolution to compress data. In this case, we need to arrange a higher density of samples in proximity of zones which c…
Phygital accessibility e next normal per il patrimonio architettonico
2021
In modi e finalità dell’uso dell’ambiente costruito, sia ordinario sia connotato da significati culturali, il COVID-19 ha accelerato cambiamenti già avviati e in cui il consolidamento della IV Rivoluzione Industriale continua a giocare un ruolo essenziale. Prefigurando gli scenari post pandemici, l’affermazione della dimensione Phygital spinge la digitalizzazione oltre l’immaterialità astratta e avulsa, cercando rinnovate connessioni e sinergie tra mondo fisico e mondo digitale collegate allo specifico luogo. Alla sfera Phygital si possono riferire i più recenti avanzamenti su accessibilità e inclusione nel patrimonio archi- tettonico: uscendo dal loop virtuale e facendo leva sulla concrete…
Kullback-Leibler distance as a measure of the information filtered from multivariate data
2007
We show that the Kullback-Leibler distance is a good measure of the statistical uncertainty of correlation matrices estimated by using a finite set of data. For correlation matrices of multivariate Gaussian variables we analytically determine the expected values of the Kullback-Leibler distance of a sample correlation matrix from a reference model and we show that the expected values are known also when the specific model is unknown. We propose to make use of the Kullback-Leibler distance to estimate the information extracted from a correlation matrix by correlation filtering procedures. We also show how to use this distance to measure the stability of filtering procedures with respect to s…
Contribution of the normal component to the thermal resistance of turbulent liquid helium
2015
Previous results for the velocity profile of the normal component of helium II in counterflow are used to evaluate the viscous contribution to the effective thermal resistance. It turns out that such a contribution becomes considerably higher than the usual Landau estimate, because in the presence of vortices, the velocity profile is appreciably different from the Poiseuille parabolic profile. Thus, a marked increase in the contribution of the normal component to the thermal resistance with respect to the viscous Landau estimate does not necessarily imply that the normal component is turbulent. Furthermore, we examine the influence of a possible slip flow along the walls when the radius of …
Isospin triplet A=14: search for states with enhanced radii
2020
Abstract This article is devoted to study of isobar-analogue states 1− in triplet A=14: 14C-14N-14O. Previously signs of neutron halo in the 1−, 6.09 MeV state of 14C were obtained by two independent groups. In this article we propose to study neighbouring nuclei 14N and 14O using the Modified diffraction model (MDM) method and the method of Asymptotic normalization coefficients (ANC). Methods were applied to experimental differential cross sections of 14C(α,α)14C scattering and reactions 13C(3He,d)14N and 14N(3He,t)14O. MDM and ANC gave practically similar within errors radii for the studied 1− states: the 6.09 MeV state in 14C – 2.7±0.1 fm, the 8.06 MeV state in 14N – 2.7 ± 0.1 fm, the 5.…
Wellentypen in Helium II-Schichten
1968
In liquid helium two wave modes are possible. Their properties may be analysed by solving the thermohydrodynamical equations under the condition that the tangential component of the normal fluid velocity is vanishing on the walls. In the present paper, these two types of wave propagation are determined for a plane-parallel capillary with the heat conduction and the thermal expansion being neglected and with the width of the capillary being much smaller than the penetration depth of a viscous wave. In particular, the dispersion relations of both, the so called fourth sound and an overdamped mode are calculated. (This overdamped mode may be called fifth wave mode.) The velocity fields can be …