A Technique for Extracting Sub-source Similarities from Information Sources Having Different Formats

In this paper we propose a semi-automatic technique for deriving the similarity degree between two portions of heterogeneous information sources (hereafter, sub-sources). The proposed technique consists in two phases: the first one selects the most promising pairs of sub-sources, whereas the second one computes the similarity degree relative to each promising pair. We show that the detection of sub-source similarities is a special case (and a very interesting one, for semi-structured information sources) of the more general problem of Scheme Match. In addition, we present a real example case to clarify the proposed technique, a set of experiments we have conducted to verify the quality of its results, a discussion about its computational complexity and its classification in the context of related literature. Finally, we discuss some possible applications which can benefit by derived similarities.     

Optimisation of a vehicle energy absorbing steel component with experimental validation

The paper deals with the optimisation of a tapered tubular steel component to be used as an energy-absorbing device in the front structure of a vehicle body. Aim of the optimisation problem is the minimisation of a load uniformity parameter evaluated as the ratio between the maximum and the average crushing loads. The optimisation problem takes into account two design variables describing a tapered geometrical configuration, the diameter of the component at one of its bounds and the tapering length. Two improved geometrical configurations have been found and have been experimentally tested to verify the numerical results with impact velocities up to 10 m/s.     

3D simulation as training tool in container terminals: The TRAINPORTS simulator

Modeling & Simulation (M&S) provides one of the best solutions for personnel and managers training in complex environments. In this article, the authors present an advanced High Level Architecture (HLA) federation of simulators (TRAINPORTS, TRAINing in marine PORTs by using Simulation), that recreates in a three-dimensional virtual environment the most important transshipment terminal of the South Mediterranean area, the Gioia Tauro container terminal. The TRAINPORTS federation includes four different federates (Straddle Carrier, Quay Crane, Forklift and Truck) and offers an advanced tool for marine port operators’ training providing the sensation of being in a real container terminal environment. The TRAINPORTS federation is part of an innovative family of simulators (called ST_VP, Simulation Team Virtual Port). This article presents the TRAINPORTS architecture, describes the federates/federation development process and discusses the simulators operation modes and verification and validation issues.     

Almost sure exponential convergence to consensus of random gossip algorithms

In this paper, we provide a proof of almost sure exponential convergence to consensus for a general class of ergodic edge selection processes. The proof is based on the multiplicative ergodic theorem of Oseledec and also applies to continuous time gossip algorithms. An example of exponential convergence in a non ergodic case is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

The online Prize-Collecting Traveling Salesman Problem

We study the online version of the Prize-Collecting Traveling Salesman Problem (PCTSP), a generalization of the Traveling Salesman Problem (TSP). In the TSP, the salesman has to visit a set of cities while minimizing the length of the overall tour. In the PCTSP, each city has a given weight and penalty, and the goal is to collect a given quota of the weights of the cities while minimizing the length of the tour plus the penalties of the cities not in the tour. In the online version, cities are disclosed over time. We give a 7/3-competitive algorithm for the problem, which compares with a lower bound of 2 on the competitive ratio of any deterministic algorithm. We also show how our approach can be combined with an approximation algorithm in order to obtain an O(1)-competitive algorithm that runs in polynomial time.     

The effect of an innovative atmospheric plasma jet treatment on physical and mechanical properties of wool fabrics

This work concerns the study of some important physical and mechanical properties of a wool fabric treated with a roll-to-roll atmospheric plasma jet equipment. The plasma pilot unit, based on a post-discharge technology, was equipped with an innovative plasma-to-fabric contactor, which promotes a relevant penetration of plasma through the fabric structure and geometrically defines the atmosphere. Wool fabrics were processed at three different velocities (1, 3 and 6 m/min); the other process variables were kept constant. Tensile strength, elongation at break, surface thickness, wettability and air permeability increased after the plasma treatment, while several low-stress mechanical properties, strictly related to the handle, were not modified. SEM analysis was also carried out to better interpret the above macroscopic results.     

Structure–property relationships in BaTiO3–BiFeO3–BiYbO3 ceramics

Ba_1?xBi_xTi_1?xYb_x/2Fe_x/2O₃ ceramics were fabricated by the solid state reaction method. X-ray diffraction analyses show 0 ≤ x ≤ 0.04 ceramics to have an average crystal structure described by the non-centrosymmetric tetragonal P4 mm space group, whereas x ≥ 0.08 ceramics are consistent with a centrosymmetric cubic perovskite (space group Pm-3 m). Coexistence of both tetragonal and cubic symmetries is observed for x = 0.06. Raman spectroscopy analysis corroborate a change in average structure with increasing x, but also show the local crystal symmetry for x ≥ 0.08 ceramics to deviate from the idealized cubic perovskite structure. Dielectric data show a ferroelectric-to-relaxor crossover, which occurs in conjunction with the change in both the average and local crystal symmetry as indicated by X-ray and Raman data. For x ≥ 0.08, ceramics exhibit relaxor behavior, which is also accompanied by a shift of the permittivity maxima towards higher temperatures with increasing x.