77 research outputs found

    Analysis of current and potential sensor network technologies and their incorporation as embedded structural system

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    This document provides a brief overview of the actual wireless ad hoc sensor networks technologies and standards available, especially in view of their possible implementation for shipping container protection and monitoring within the framework of the STEC Action aiming at analyzing possible technical solutions to improve the security of the millions of containers moving in and out of Europe. Examples of applications and research projects are reported from the literature to give insights on the possibility of implementation of wireless sensor networks in real world scenarios.JRC.G.5-European laboratory for structural assessmen

    Impact of Structural Damage on Network Accessibility Following a Disaster: the Case of the Seismically Damaged Port Au Prince Urban Road Network

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    The catastrophic seismic event that struck Haiti in January 2010 led to an unprecedented effort in collecting and providing geographical information in support of the humanitarian aid. Although most of the compiled datasets and generated maps try to provide specific and detailed information on the location of damage and road interruptions, little or no information was available in terms of accessibility of the urban space. Here we try to offer an alternative method in defining the urban aftermath damage, coupling graph theory and GIS-based spatial analysis to assess how the urban space accessibility decreases when the road network is damaged. We believe there could be important lessons to be learnt from this exercise in the event of the physical failure of critical elements of European infrastructure.JRC.DG.G.5-European laboratory for structural assessmen

    Robustness of Trans-European Gas Networks

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    Here we uncover the load and fault-tolerant backbones of the trans-European gas pipeline network. Combining topological data with information on inter-country flows, we estimate the global load of the network and its tolerance to failures. To do this, we apply two complementary methods generalized from the betweenness centrality and the maximum flow. We find that the gas pipeline network has grown to satisfy a dual-purpose: on one hand, the major pipelines are crossed by a large number of shortest paths thereby increasing the efficiency of the network; on the other hand, a non-operational pipeline causes only a minimal impact on network capacity, implying that the network is error-tolerant. These findings suggest that the trans-European gas pipeline network is robust, i.e., error tolerant to failures of high load links.Comment: 11 pages, 8 figures (minor changes

    GIS-based method to assess seismic vulnerability of interconnected infrastructure: A case of EU gas and electricity networks

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    Our study concerns the interconnected European Electricity and Gas transmission grid where we address two important issues of these interdependent critical infrastructures. First we assessed the response under seismic hazard for each independent network; then we analysed the increased vulnerability due to coupling between these two heterogeneous networks. We developed a probability reliability model that encompasses the spatial distribution of the network structures using a Geographic Information System (GIS). We applied the seismic risk assessment of individual network facilities and presented the results in the form of the system fragility curves of the (independent and dependant) networks in terms of various performance measures - connectivity loss, power loss, and impact on the population. We characterized the coupling behaviour between the two networks as a physical dependency: here the electricity grid, in part, depends on the gas network due to the generation capacity of gas-fired power plants. The dependence of one network on the other is modelled with an interoperability matrix, which is defined in terms of the strength of coupling; additionally we consider how the mechanical-structural fragility of the pipelines of the gas-source supply stream contributes to this dependence. In addition to network-wide assessment, damage was also evaluated at a local level by examining the performance status of each and every electricity distribution substation in the electricity grid. Finally, the comprehensive geographical distributions of performance loss at the European level can be visualized on a GIS tool; showing, as expected, that the highest direct damage in southeast Europe.JRC.DG.G.5-European laboratory for structural assessmen

    DBDsoft per la progettazione sismica. Un software innovativo per la progettazione sismica di strutture basato sul metodo diretto agli spostamenti (Direct Displacement Based Design)

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    La procedura di progettazione sismica basata sul metodo agli spostamenti (Direct Displacement Based Design - DDBD) è stata sviluppata molto per diversi sistemi strutturali e varie tipologie di materiali. Tuttavia, al momento, non sembrano esserci ancora applicazioni software che implementino tale approccio. E’ stato pertanto avviato un progetto di ricerca al EUCENTRE, finanziato dal Dipartimento della Protezione Civile, per lo sviluppo di un programma per computer denominato DBDSoft per la progettazione sismica di strutture basato sul metodo DDBD. Lo sviluppo del programma ha richiesto la risoluzione di diverse problematiche e un approccio innovativo rispetto ai tradizionali programmi di ingegneria. Nel presente articolo sono riportati alcuni cenni di teoria del metodo implementato e sono descritte le funzionalità del programma per la progettazione di edifici a telaio o con pareti in cemento armato. Lo sviluppo del presente programma ha richiesto la definizione di un nuovo approccio alla progettazione che consente l’assegnazione delle proporzioni di resistenza dei sistemi strutturali e la configurazione della posizione delle cerniere plastiche. Una volta definiti questi aspetti della struttura, il programma esegue analisi di equilibrio al fine di definire i valori delle forze di progetto, in linea con il metodo diretto DBD. I limiti dell’attuale versione del software sono discussi e sono identificate le aree di ricerca importanti per i futuri sviluppi del programma.JRC.G.5-European laboratory for structural assessmen

    Analysis of Intermittent Distributed Connectivity in Urban Areas

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    Analysis of hypothetical connectivity of wirelessly interconnected networks and infrastructures deployed over a one-square kilometre of the Brussels Metropolitan area is presented. Upper and lower margins of wireless transceiver range are considered with a view to characterise representative interconnectivity profiles. Graph and percolation analyses of intermittent connectivity and its implications for resilience and vulnerability of the network are discussed. Based on these findings the report presents a proposal for the dimensioning of connectivity profiles for generic areas based on intrinsic algebraic network properties.JRC.E.4-Safety and Security of Building

    Congestion dependencies in the European gas pipeline network during crises.

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    Conflicts, geo-political crises, terrorist attacks, or natural disasters can turn large parts of energy distribution networks off-line, creating unexpected congestion in the remaining infrastructure. Given the importance of the security of natural gas supply, we need models that enable the management of network congestion, especially during crises. We develop a decentralized model of congestion control to explore the effects of removing supply or transit countries from the network. Recently, in R. Carvalho et. al. PLoS ONE, Vol. 9, no. 3, 2014, we evaluated how cooperation between countries helps to mitigate the effect of crises. Here, we extend our previous results by exploring the structure of downstream and upstream congestion dependencies between countries

    From Complex Networks to Time Series Analysis and Viceversa: Application to Metabolic Networks

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    In this work we present a simple and fast approach to generate network structures based on time series recurrence plots and viceversa. In addition, we discuss the application of the different analysis techniques developed in both fields, i.e. complex networks and time series analysis. Concerning the transformation from time series to networks, we propose a deterministic growth procedure which produces a new types of complex network structures that have some interesting features. This simple and fast approach is able to generate deterministic network structures based on time series recurrence plots. The generated networks contain several properties of the original time series. In this case, networks generated from chaotic attractors display interesting features from the point of view of robustness which could help in designing systems with high tolerance against errors and transfer of information. Chaotic networks based on the Lorenz attractor show that they are highly tolerant against attacks and they have a high ability for the transfer of information or on the contrary they are able to transmit infections faster. It is still necessary to investigate if such chaotic networks exist already in natural or man-made systems or, if possible, to construct such networks and test their properties. On the other hand, the transformation from networks to time series presents some problems concerning the selection of the initial time or in our case the initial node and the way in which the nodes are visited. If a network has been generated following a certain growth law it seems logical to choose the first node as the origin and then proceed following the network growth pattern. However, the situation is not so clear for example with metabolic networks, where it is difficult to select which is the first metabolite. Similar concerns would apply to other types of biological networks. In this case several alternatives could be considered, e.g. ordering using the number of connections. However, we have still to find if there are some invariant/preserved properties in the generated time series from the same network. We have found that rescaled range analysis does not preserve the fractal structure in the time series. In any case, if time series parameters would be invariant against the initial node selection, then they could be used to analyze the networks that have generated said time series. Our future work will continue along these lines.JRC.I.6-Systems toxicolog

    A JRC FIWARE Testbed for SMART Buildings and Infrastructures: Implementation of the FIWARE platform for performance testing and heterogeneous sensor nodes

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    The present work reports on the activities for the implementation of a SMART City testbed based on the EC supported open source platform FIWARE. The system architecture complies with the EC JRC network IT security constraints and oered the performance testing and the analysis of the challenges for the integration of commercial devices, with the integration of the wireless sensor network system in use at the JRC E.4 Unit for the monitoring of structures during experimental tests. The implemented testbed will provide support for future works and developments of larger systems and integration with heterogeneous Internet of Things (IoT) devices, numerous communication protocols and big data analysis.JRC.E.4-Safety and Security of Building

    Hide and seek between Andromeda's halo, disk, and giant stream

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    Photometry in B, V (down to V ~ 26 mag) is presented for two 23' x 23' fields of the Andromeda galaxy (M31) that were observed with the blue channel camera of the Large Binocular Telescope during the Science Demonstration Time. Each field covers an area of about 5.1kpc x 5.1kpc at the distance of M31 ((m-M)o ~ 24.4 mag), sampling, respectively, a northeast region close to the M31 giant stream (field S2), and an eastern portion of the halo in the direction of the galaxy minor axis (field H1). The stream field spans a region that includes Andromeda's disk and the giant stream, and this is reflected in the complexity of the color magnitude diagram of the field. One corner of the halo field also includes a portion of the giant stream. Even though these demonstration time data were obtained under non-optimal observing conditions the B photometry, acquired in time-series mode, allowed us to identify 274 variable stars (among which 96 are bona fide and 31 are candidate RR Lyrae stars, 71 are Cepheids, and 16 are binary systems) by applying the image subtraction technique to selected portions of the observed fields. Differential flux light curves were obtained for the vast majority of these variables. Our sample includes mainly pulsating stars which populate the instability strip from the Classical Cepheids down to the RR Lyrae stars, thus tracing the different stellar generations in these regions of M31 down to the horizontal branch of the oldest (t ~ 10 Gyr) component.Comment: 59 pages, 26 figures, 12 tables, ApJ in pres
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