a emph{signed graph} (or, in short, emph{sigraph}) $s=(s^u,sigma)$ consists of an underlying graph $s^u :=g=(v,e)$ and a function $sigma:e(s^u)longrightarrow {+,-}$, called the signature of $s$. a emph{marking} of $s$ is a function $mu:v(s)longrightarrow {+,-}$. the emph{canonical marking} of a signed graph $s$, denoted $mu_sigma$, is given as $$mu_sigma(v) := prod_{vwin e(s)}sigma(vw).$$the li...

Let n 1 be an integer. The hypercube Qn is the graph whose vertex set isf0;1gn, where two n-tuples are adjacent if they differ in precisely one coordinate. This graph has many applications in Computer sciences and other area of sciences. Inthe graph Qn, the layer Lk is the set of vertices with exactly k 1’s, namely, vertices ofweight k, 1 k n. The hyper-star graph B(n;k) is...

In the past years, many properties of the critical behavior of the largest connected components on the high-dimensional torus, such as their sizes and diameter, have been established. The order of magnitude of these quantities equals the one for percolation on the complete graph or Erdős-Rényi random graph, raising the question whether the scaling limits or the largest connected components, as ...

A. We study the Glauber dynamics for the Ising model on the complete graph, also known as the Curie-Weiss Model. For β < 1, we prove that the dynamics exhibits a cut-off: the distance to stationarity drops from near 1 to near 0 in a window of order n centered at [2(1 − β)]−1n log n. For β = 1, we prove that the mixing time is of order n3/2. For β > 1, we study metastability. In particula...

We analyse the time evolution of two open source Java projects: Eclipse and Netbeans, both developed following agile practices, though to a different extent. Our study is centered on quality analysis of the systems, measured as defects absence, and its relation with software metrics evolution. The two projects are described through a software graph in which nodes are represented by Java files a...

We consider activity-centered tasks in email, including the novel tasks of predicting future involvement of persons from the enterprise in an ongoing activity represented by a folder, and a novel task where we identify email messages that are related to a to-do item. We also evaluate the task of email foldering, and the inverse task, of tracking messages relevant to a folder associated with an ...

A. We study the Glauber dynamics for the Ising model on the complete graph, also known as the Curie-Weiss Model. For β < 1, we prove that the dynamics exhibits a cut-off: the distance to stationarity drops from near 1 to near 0 in a window of order n centered at [2(1 − β)]−1n log n. For β = 1, we prove that the mixing time is of order n3/2. For β > 1, we study metastability. In particula...

In the usual forms of homogeneity analysis (which are also known as multiple correspondence analysis or MCA) the size of a point set is defined as the size of the star plot of the set. The star plot is the graph defined by connecting all points in the set with their centroid, and the size is the total squared length of the edges. In order to prevent trivial solutions the configuration X is usua...