Search results for "Mathematic"

Measuring galaxy segregation with the mark connection function

2010

(abridged) The clustering properties of galaxies belonging to different luminosity ranges or having different morphological types are different. These characteristics or `marks' permit to understand the galaxy catalogs that carry all this information as realizations of marked point processes. Many attempts have been presented to quantify the dependence of the clustering of galaxies on their inner properties. The present paper summarizes methods on spatial marked statistics used in cosmology to disentangle luminosity, colour or morphological segregation and introduces a new one in this context, the mark connection function. The methods used here are the partial correlation functions, includi…

Recursive estimators 1

1991

In this paper, we present first the recursive estimation of parameters of linear regression models and we show the link between a matrix of projection and a matrix of gain. Two cases are examined : constant parameters and parameters changing over time. In the second part the recursion formulae for the two stage least squares are given.

Des capacités de choix aux probabilités de choix (un théorème de conversion)

1992

Une partie importante de la théorie des choix discrets concerne les développements du modèle de Luce 1959]. Cette place privilégiée provient sans nul doute de l’extrême élégance de PAxiome du Choix qui permet d’une part, d’introduire une sorte de rationalité imparfaite du comportement en autorisant la construction de probabilités de choix et d’autre part, de décrire un processus de choix qui semble raisonnablement réaliste : en effet, il est suggéré que l’agent faisant face à un ensemble fini d’actions, choisit dans un premier temps un sous-ensemble, puis finalement, à l ’intérieur de ce sous-ensemble, une action. Il existe de nombreuses versions de ce modèle ( Yellot [1977], Strauss [1980]…

Creating an image of people with disabilities in formal education. Analysis of the textbooks used in the chosen European countries

2016

Creating an image of people with disabilities in formal education is an important element of educating young people into a full and unbiased understanding of the needs and reality of these people. Consequently, it is an element of creating a social climate around people with disabilities and influencing state policy in this area. Therefore, I find it extremely important to analyse and compare ideas worked out in different countries in order to correctly assess our own situation and find inspiring and applicable solutions. In the text, I focused on one component of the system of formal education, i.e. selected textbooks used in Poland and Sweden in which I highlighted their disability-relate…

On a stochastic SIR model

2007

We consider a stochastic SIR system and we prove the existence, uniqueness and positivity of solution. Moreover the existence of an invariant measure under a suitable condition on the coefficients is studied.

Stability of stochastic nonlinear systems with state-dependent switching

2013

In this paper, the problem of stability on stochastic systems with state-dependent switching is investigated. To analyze properties of the switched system by means of Itô’s formula and Dynkin’s formula, it is critical to show switching instants being stopping times. When the given active-region set can be replaced by its interior, the local solution of the switched system is constructed by defining a series of stopping times as switching instants, and the criteria on global existence and stability of solution are presented by Lyapunov approach. For the case where the active-region set can not be replaced by its interior, the switched systems do not necessarily have solutions, thereby quasi-…

Mathematical Methods for Research Excellence : Book of Abstracts

2022

I poligoni stellati: origini storiche ed implicazioni didattiche

2019

The genesis of mathematical concepts in the evolutionary line of human thought in the long story and the genesis in individual optics possess evident analogies. Starting from this assumption, we describe an activity presented to 15-year-old students; the aim was to consolidate fundamental concepts of Euclidean geometry related to regular polygons. The experimentation has used a didactic approach based on the historical evolution of the formal definition of regular star polygon through the centuries. The activity and the results obtained in terms of internalization of the concepts in the students are showed.

Comment renouveler la stratégie marketing ? Quand le cinéma peut inspirer les stratèges.

2006

Certains succes cinematographiques deviennent de veritables phenomenes de societe. Leur analyse offre de multiples pistes de reflexion concernant de nouvelles options de mise en relation de l'offre avec le marche.

Intelligence stratégique et dissimulation dans les outils de géovisualisation en ligne

2014

Interactive geovisualization portals, set up on the Internet after the iconic Google Maps, are highly regarded by the public. They provide the ability to see from above the surface of our planet, and more specifically the French territory in the case of Geoportail. Yet it is forbidden to approach too close to certain objects: on national territory, some 150 sites are in fact hidden by the IGN. This paper question the relevance and efficiency of this operation imposed on the main body of production and dissemination of spatial information in France, in comparison with the means used by other countries.