Sufficient conditions for a digraph to admit a (1,=l)-identifying code

A (1, = `)-identifying code in a digraph D is a subset C of vertices of D such that all distinct subsets of vertices of cardinality at most ` have distinct closed in-neighbourhoods within C. In this paper, we give some sufficient conditions for a digraph of minimum in-degree d - = 1 to admit a (1, = `)- identifying code for ` ¿ {d -, d- + 1}. As a corollary, we obtain the result by Laihonen that states that a graph of minimum degree d = 2 and girth at least 7 admits a (1, = d)-identifying code. Moreover, we prove that every 1-in-regular digraph has a (1, = 2)-identifying code if and only if the girth of the digraph is at least 5. We also characterize all the 2-in-regular digraphs admitting a (1, = `)-identifying code for ` ¿ {2, 3}.Peer ReviewedPostprint (author's final draft

Differentiations in structures of employees' resources: a comparison of eight European countries

Using data from the European Community Household Panel (ECHP), the research presented in this paper analyses structures of employees’ incomes, how they differ across countries, how they are related to socio-economics characteristics of employees, and how they have evolved over the last decade. Section 1 reviews the main recent research in different disciplines related to the study of the linkages between employment and social protection. It highlights the relevance of analysing the structure of income, arguing that instituted forms of resources flows matter in the definition of employment status and social rights. The main hypothesis is that the nature of resources could be related to processes of labour market segmentation and social differentiation and used as an analyser of changes in employment and social rights.Section 2 presents the dataset and methodology used in the analysis of employees’ structure of income. The use of the European Household Panel (ECHP) enabled to compare data for eight European countries and between two dates in the 1990s referring to income structure and socio-economic characteristics of employees. Section 3 presents the main results of the cross-sectional analysis of income structure. It displays classification of countries and examine differentiations across social groups. It proposes some elements to interpret national configurations of employees’ income structure in relation with trends over labour markets and social policies in the different countries.income ; employment ; European comparison ; labour market ; social policies

Saint-Martin-d’Ardèche – Abri du Maras

Code INSEE de la commune : 07268Lien Atlas (MCC) :http://atlas.patrimoines.culture.fr/atlas/trunk/index.php?ap_theme=DOM_2.01.02&ap_bbox=4.544;44.292;4.600;44.323 La campagne 2013 a porté principalement sur deux secteurs du site : La partie est, au niveau des carrés J-O et des bandes 6, 7 et 8. La partie ouest (carrés E-F/7-8), dans le secteur d’une dalle de 4 m² qui avait été préservée. Celle-ci a été éliminée. Par ailleurs, plusieurs dosimètres ont été placés le long de la coupe principale ..

Il sito di Guado San Nicola

Il sito paleolitico di Guado San Nicola prende il nome dall’omonima località posta nelle immediate vicinanze della frazione di Sant’Eusanio, a qualche chilometro a nord-ovest del centro abitato di Monteroduni, in provincia di Isernia. Il giacimento, oggetto di scavi sistematici dal 2008, si trova a 250 m s.l.m., sulla sinistra idrografica del fiume Volturno

Problems to put students in a role close to a mathematical researcher

In this workshop, we present a model of problem that we call Research Situation for the Classroom (RSC). The aim of a RSC is to put students in a role close to a mathematical researcher in order to make them work on mathematical thinking/skills. A RSC has some characteristics : the problem is close to a research one, the statement is an easy understandable question, school knowledge are elementary, there is no end, a solved question postponed to new questions... The most important characteristic of a RSC is that students can manage their research by fixing themselves some variable of the problem. So, a RSC is completely different from a problem that students usually do in France. For short : there is no final answer, students can try to resolve their own questions : a RSC is a large open field where many sub-problems exist; the goal for the students is not to apply a technique: the goal is, as for a researcher, to search. These type of situations are particularly interesting to develop problem solving skills and mathematical thinking. They can also let students discover that mathematics are “alive” and “realistic”. This workshop will be split into two parts. First, we propose to put people in the situation of solving a RSC to make them discover practically what is it. After, we present the model of a RSC and some results of our experimentations