Real-time traffic control in railway systems

Despite the constantly increasing demand of passengers and goods transport in Europe, the share of railway traffic is decreasing. One major reason appears to be congestion, which in turn results in frequent delays and in a general unreliability of the system. This fact has triggered the study of efficient ways to manage railway traffic, both off-line and real-time, by means of optimization and mathematical programming techniques. And yet, to our knowledge, there are only a few fully automated real-time traffic control systems which are actually in operation in the European railway system; in most cases such systems only control very simple lines and actually they only support the activity of human dispatchers. We describe here two recent optimization based applications to real-time traffic control which have actually been put into operation in the Italian railways. One such system has been able to fully control the trains in the terminal stations of Milano metro system. The other one will be fully operative by the end of 2012, when it will control the trains on several Italian single-track railways. Both systems heavily rely on mixed integer programming techniques to elaborate good quality timetables in real time

Towards Global Neural Network Abstractions with Locally-Exact Reconstruction

Neural networks are a powerful class of non-linear functions. However, their black-box nature makes it difficult to explain their behaviour and certify their safety. Abstraction techniques address this challenge by transforming the neural network into a simpler, over-approximated function. Unfortunately, existing abstraction techniques are slack, which limits their applicability to small local regions of the input domain. In this paper, we propose Global Interval Neural Network Abstractions with Center-Exact Reconstruction (GINNACER). Our novel abstraction technique produces sound over-approximation bounds over the whole input domain while guaranteeing exact reconstructions for any given local input. Our experiments show that GINNACER is several orders of magnitude tighter than state-of-the-art global abstraction techniques, while being competitive with local ones.Comment: Under submission to the Neural Networks Journal (revised version). Sections 2, 4.7, 5.4, Appendix A and B have been adde

La narrativa quechua contemporánea en Perú como sistema : el inmenso caleidoscopio de la literatura latinoamericana.

El libro en cuestión da cuenta, crítica y detalladamente, de una cartografía de escrituras quechuas que inician en 1970 y que, por años, fueron invisibilizadas en el sistema literario latinoamericano. El estudioso moche emprende la tarea que Antonio Cornejo Polar (1989), en “Apéndice: La literatura peruana como totalidad contradictoria” propone como ineludible: pensar a la multiplicidad del escenario escriturario en Latinoamérica como una totalidad contradictoria. Para entender las producciones literarias que representan al plano social y cultural de nuestro continente se debe atender a los dinamismos que subyacen en el sistema. Estamos ante un movimiento y el libro de Espino Relucé es un fuerte e innovador aporte para ello

Vespa velutina Lepeletier (Hymenoptera Vespidae): a first assessment two years after its arrival in Italy

Vespa velutina nigrithorax is an invasive alien social wasp species known as harmful for its effective prey pressure on Apis mellifera. The aim of this work was to assess the presence of V. v. nigrithorax two years after the first capture in North West Italy, to evaluate its relative abundance and dominance in the social wasp communities sampled by means of bait-traps, and to describe some biological and nesting activity. V. v. nigrithorax was trapped or observed in 4 localities in Piedmont and in 10 localities in Liguria, from 20 m a.s.l. up to 1100 m a.s.l. Five embryo and eight developed nests were counted in eight different localities. V. v. nigrithorax was a subdominant species in the social wasp community trapped at Giardini Hanbury (Liguria). At present, V. v. nigrithorax is spreading in North West of Italy at a rate of 10-20 Km per year and measures for its spatial containment should be urgently implemented