In this paper, we analyze statistical properties of a communication network constructed from the records of a mobile phone company. The network consists of 2.5 million customers that have placed 810 million communications (phone calls and text messages) over a period of 6 months and for whom we have geographical home localization information. It is shown… (More)
We analyze linkage strategies for a set I of webpages for which the webmaster wants to maximize the sum of Google's PageRank scores. The webmaster can only choose the hyperlinks starting from the webpages of I and has no control on the hyperlinks from other webpages. We provide an optimal linkage strategy under some reasonable assumptions.
The paper introduces a novel algorithm derived from the PageRank algorithm of Brin and Page. The PageRank algorithm interprets an hyperlink from page a to page b as being a positive vote from a to b. Starting from this interpretation , it attributes a rank to each page. However, it does not offer the possibility to take into account negative votes. The… (More)
The paper introduces a novel iterative method that assigns a reputation to n + m items: n raters and m objects. Each rater evaluates a subset of objects leading to a n × m rating matrix with a certain sparsity pattern. From this rating matrix we give a nonlinear formula to define the reputation of raters and objects. We also provide an iterative algorithm… (More)
We introduce the definition of Social Leader that gives a local centrality measure for each node in a graph. A node u is a Social Leader if the number of cycles of length 3 passing through u is greater than the corresponding number for its neighbors. This concept is used to visualize large graphs, identify in-fluent agents in social networks (word of mouth… (More)
We present the combinatorial 2-player game clobber and its 1-player version solitaire clobber. We present some old and recent results on both games.