The Comite Consultatif pour la Definition de la Seconde* (CCDS) created in March 1996 a Working Group on the expression of uncertainties in primary frequency standards. This paper presents the main topics included in the first report of the Working Group dated April 1997. This report gives a brief review of the conditions which led to the creation of the Working Group and a summary of the discu...

We give two direct proofs of Sobolev estimates for the positive part of Boltzmann's kernel. The rst deals with a cross section with separated variables; no derivative is needed in this case. The second is concerned with a general cross section having one derivative in the angular variable. R esum e. Nous donnons deux preuves directes des estimations de Sobolev pour la partie positive du noyau d...

Résumé La sécurité des Clouds est un aspect essentiel qui n’est pas forcément abordé selon le point de vue de l’utilisateur. En particulier, sur une plate-forme de type Infrastructure-as-a-Service (IaaS), il est actuellement impossible pour un utilisateur de certifier de manière fiable et sécurisée que l’environnement qu’il a déployé (typiquement sous forme d’une machine virtuelle) est toujours...

In an Arc Consistency (AC) algorithm, a residual support, or residue, is a support that has been stored during an execution of the procedure which determines if a value is supported by a constraint. The point is that a residue is not guaranteed to represent a lower bound of the smallest current support of a value. In this paper, we study the theoretical impact of exploiting residues with respec...

We introduce a new family of polyominos that are inscribed in a rectangle of given size for which we establish a number of exact formulas and generating functions. In particular, we study polyominos inscribed in a rectangle with minimum area and minimum area plus one. These results are then used for the enumeration of lattice trees inscribed in a rectangle with minimum area plus one. Résumé. No...

The relationship between current abundance and future recruitment to the stock is fundamental to managing fish populations. However, many different recruitment models are plausible and the data are insufficient to distinguish among them. Although nonparametric methods may be used to circumvent this problem, these are devoid of biological underpinnings. Here, we present a Bayesian nonparametric ...

The Severi degree is the degree of the Severi variety parametrizing plane curves of degree d with δ nodes. Recently, Göttsche and Shende gave two refinements of Severi degrees, polynomials in a variable q, which are conjecturally equal, for large d. At q = 1, one of the refinements, the relative Severi degree, specializes to the (non-relative) Severi degree. We give a combinatorial description ...

Résumé – Les méthodes classiques d’estimation dense de la vitesse (de type flot optique) s’appuient sur l’estimation des dérivées spatio-temporelles de l’image. Celles-ci sont difficiles à estimer dans le cas d’occlusion d’une partie des acquisitions. Les approches issues de l’assimilation de données s’appuient sur un modèle d’évolution temporelle, qui permet de répondre à ce problème des donné...

An analytical analysis has been presented to evaluate the performance of a solar-assisted va-pour absorption cooling system with flat-plate absorber plate. The lithium–bromide water cycle is used obsstain effect. parameters, namely plate efficiency, collector efficiency factor, heat removal etc. have deter-mined variation fluid inlet temperature. coefficient perfor-mance (COP), COP, refrigerati...