Opinion formation with upper and lower bounds

We investigate the opinion formation with upper and lower bounds. We formulate the binary exchange of opinions between two individuals, and effects of the self-thinking and political party using the relativistic Boltzmann-Vlasov type equation with the randomly perturbed motion. The convergent form of the distribution function is determined by the balance between the cooling rate via the binary exchange of opinions between two individuals and the concentration of opinions by the political party, and heating rate via the self-thinking.Comment: We revised in April 201

SimGrid: a Sustained Effort for the Versatile Simulation of Large Scale Distributed Systems

In this paper we present Simgrid, a toolkit for the versatile simulation of large scale distributed systems, whose development effort has been sustained for the last fifteen years. Over this time period SimGrid has evolved from a one-laboratory project in the U.S. into a scientific instrument developed by an international collaboration. The keys to making this evolution possible have been securing of funding, improving the quality of the software, and increasing the user base. In this paper we describe how we have been able to make advances on all three fronts, on which we plan to intensify our efforts over the upcoming years.Comment: 4 pages, submission to WSSSPE'1

A similarity-based community detection method with multiple prototype representation

Communities are of great importance for understanding graph structures in social networks. Some existing community detection algorithms use a single prototype to represent each group. In real applications, this may not adequately model the different types of communities and hence limits the clustering performance on social networks. To address this problem, a Similarity-based Multi-Prototype (SMP) community detection approach is proposed in this paper. In SMP, vertices in each community carry various weights to describe their degree of representativeness. This mechanism enables each community to be represented by more than one node. The centrality of nodes is used to calculate prototype weights, while similarity is utilized to guide us to partitioning the graph. Experimental results on computer generated and real-world networks clearly show that SMP performs well for detecting communities. Moreover, the method could provide richer information for the inner structure of the detected communities with the help of prototype weights compared with the existing community detection models

Non-unique ergodicity, observers' topology and the dual algebraic lamination for R\R-trees

We continue in this article the study of laminations dual to very small actions of a free group F on R-trees. We prove that this lamination determines completely the combinatorial structure of the R-tree (the so-called observers' topology). On the contrary the metric is not determined by the lamination, and an R-tree may be equipped with different metrics which have the same observers' topology.Comment: to appear in the Illinois Journal of Mat