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Despite of its many shortcomings, Pearson’s rho is often used as an association measure for stock returns. A conditional version of Spearman’s rho is suggested as an alternative measure of association. This approach is purely nonparametric and avoids any kind of model misspecification. We derive hypothesis tests for the conditional rank-correlation coefficients particularly arising in bull and bear markets and study their finite-sample performance by Monte Carlo simulation. Further, the daily returns...
To validate pollution data, subject-matter experts in Airpl (an organization
that maintains a network of air pollution monitoring stations in western
France) daily perform visual examinations of the data and check their
consistency. In this paper, we describe these visual examinations and
propose a formalization for this problem. The examinations consist
in comparisons of so-called shorth intervals so we build a statistical
test that compares such intervals in a nonparametric regression model.
This...
To validate pollution data, subject-matter experts in Airpl (an organization that maintains a network of air pollution monitoring stations in western France) daily perform visual examinations of the data and check their consistency. In this paper, we describe these visual examinations and propose a formalization for this problem. The examinations consist in comparisons of so-called shorth intervals so we build a statistical test that compares such intervals in a nonparametric regression model. This...
Frente a la visión antigua de controlar la calidad mediante la inspección final, o la clásica del control estadístico del proceso, la forma que actualmente podríamos denominar moderna, y desde luego la más económica de asegurar la calidad, consiste en diseñar productos tales que sus prestaciones se mantengan en el nivel deseado aunque éstos no se hayan fabricado en las condiciones más adecuadas, o se hayan elaborado con materias primas que no reúnan las condiciones óptimas, o bien que sean utilizados...
This paper describes a modification of the kriging method for working with the square root transformation of a spatial random process. We have developed this method for the situation where the spatial process observed is not supposed to be stationary but the assumption is that its square root is a second order stationary spatial random process. Consequently this method is developed for estimating the integral of the process observed and finally some application of the method is given to data from...
Patients with acute myeloblastic leukemia (AML) are divided according to the French
American British (FAB) classification into eight subgroups (M0 to M7) on the basis of their degree
of maturation/differentiation. However, even if immunophenotypical characterization by flow cytometry
is routinely used to distinguish between AML and acute lymphoblastic leukemia (ALL), it
is not yet well established for the identification within the AML subgroups. Here we show that certain
subgroups of AML can be...
The motivation for this paper arises out of the authors experiences in modelling real decision makers where the decisions show not only a continuous response to a continuously changing environment but also sudden or discontinuous changes. The theoretical basis involves a parametric characterisation of the environment, a decision makers perception of it in terms of a twice differentiable Distribution Function and a bounded Loss Function. Under a specified minimizing dynamic, the resultant Expected...
Different kinds of renewal equations repeatedly arise in connection
with renewal risk models and variations. It is often appropriate to
utilize bounds instead of the general solution to the renewal
equation due to the inherent complexity. For this reason, as a first
approach to construction of bounds we employ a general Lundberg-type
methodology. Second, we focus specifically on exponential bounds
which have the advantageous feature of being closely connected to
the asymptotic behavior (for large...
L’objectif de cet article est d’illustrer la nature multi-échelle de quelques systèmes naturels en sciences de l’univers. Nous nous intéressons tout d’abord à l’onde circumpolaire Antarctique, une des manifestations les plus marquantes de la variabilité australe. Sa variabilité est analysée à partir de relevés de stations de météorologie côtières du continent Antarctique, fournissant des données de température depuis 1955. Grâce à une « décomposition modale empirique » (DME) couplée à une analyse...
Short-term prediction of solar flare activity using multiple regression methods was considered. The variables describing active regions the given day were used to predict the flare activity on the next day. Two groups of observational data covering the years 1988 and 1989 were dealt with. Some variants of the distance-based regression as proposed by Cuadras and Arenas (1990) appeared to be superior to the ordinary least squares method by describing more accurately the data sets under consideration....
On montre comment les outils classiquement utilisés pour parler de concentration d'une mesure par rapport à une autre, considérée comme référence, permettent d'introduire la notion de distorsion entre deux mesures, dans laquelle ces dernières jouent des rôles symétriques. Ceci permet de résoudre divers problèmes posés par l'étude des inégalités : évolutions paradoxales de deux sous-populations complémentaires, évaluation de la contribution de chaque modalité à la distorsion ou à son évolution.
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