Computational and model-theoretic properties of logical languages constitute a central field of research in logic-based knowledge representation. Datalog is a very popular formalism, a de-facto standard for expressing and querying knowledge. Diverse results exist regarding the expressivity of Datalog and its extension by input negation (semipositive Datalog) and/or a linear order (orderinvarian...

We present a simple unified algorithmic process which uses either LexBFS or MCS on a chordal graph to generate the minimal separators and the maximal cliques in linear time in a single pass.

In this paper we establish a relationship between the asymptotic form of conditional boundary crossing probabilities and first passage time densities for diffusion processes. We show that, under the assumption that the conditional probability that our diffusion (Xs, s ≥ 0) doesn’t cross an upper boundary g(·) prior to time t given that Xt = z behaves as (a+ o(1))(g(t)− z) as z ↑ g(t), there exi...

After introducing the concept of commutativity for continuous-time linear time-varying systems, the related literature and the results obtained so far are presented. For a simple introduction of the commutativity of discrete-time linear time-varying systems, the problem is formulated for first-order systems. Finally, explicit necessary and sufficient conditions for the commutativity of first-or...

We present a linear time algorithm for unit interval graph recognition. The algorithm is simple and based on Breadth-First Search. It is also direct | it does not rst recognize the graph as an interval graph. Given a graph G, the algorithm produces an ordering of the vertices of the graph whenever G is a unit interval graph. This order corresponds to the order of the intervals of some unit inte...

We present analytical expressions for the time-dependent and stationary probability distributions corresponding to a stochastically perturbed onedimensional flow with critical points, in two physically relevant situations: delayed evolution, in which the flow alternates with a quiescent state in which the variate remains frozen at its current value for random intervals of time; and interrupted ...

We test how ownership breadth predicts stock returns. Using holdings data on a representative Shanghai Stock Exchange investor sample from 1996 to 2007, we find that cross-sectionally, high breadth change quintile stocks underperform low breadth change quintile stocks by 22 percent per year, a result driven by retail investor ownership breadth. This is consistent with breadth increases primaril...

When does a diffusing particle reach its target for the first time? This first-passage time (FPT) problem is central to the kinetics of molecular reactions in chemistry and molecular biology. Here, we explain the behavior of smooth FPT densities, for which all moments are finite, and demonstrate universal yet generally non-Poissonian long-time asymptotics for a broad variety of transport proces...

In recent years, several real-time or near real-time object detectors have been developed. However these object detectors are typically designed for first-person view images where the subject is large in the image and do not directly apply well to detecting vehicles in aerial imagery. Though some detectors have been developed for aerial imagery, these are either slow or do not handle multi-scal...

ions of Time Series Data Using CBR G. Leonardi (*), A. Bottrighi, S. Montani and L. Portinale (*) Universitá di Pavia, Pavia (Italy) Universitá del Piemonte Orientale, Alessandria (Italy) Abstract. In the haemodialysis domain, we are implementing a caseIn the haemodialysis domain, we are implementing a casebased architecture aimed at configuring Temporal Abstractions (TA) to be applied to time ...