58 research outputs found

    critical infrastructure disruption scenarios analyses via simulation

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    The ultimate target of Modelling and Simulation (M&S) activities in the field of CIP is to provide Models, Methodologies and tools to help in the analysis of different crisis' scenarios and, subsequently, in crisis management decision making. A CIs' disruptions scenario is simply a sequence of random events following a well-defined chronological order. Generally, each identified scenario produces a set of consequences which is a function of: the initiating event, the concerned CIs and the geo-organizational context of the disrupted CIs. Formal sciences represent the reality of our surrounding world. But formal sciences are imperfect and what we call "reality" is the projection of the inaccessible "Reality" on our world. This projection is the only reality we are talking about in formal sciences. Subsequently, formal sciences construct objects in which small parts of the sensible reality are grasped and formalized. These objects can be called "models". We are limiting our interest here to formal sciences and engineering activities that cover both conceptual and phenomenological modelling processes. Models are first validated before being admitted in the construction of a global model of the sensible reality. Regarding our focus on crisis scenarios modelling, simulation and analysis (MS&A), engineers' ambition is to simulate not only independent isolated phenomenon but also interacting multi-physic multi-scale phenomenon

    Simulation of growth of Ni-Zr interfacial amorphous regions under nonequilibrium conditions

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    We have simulated the response of an interfacial amorphous region formed between nickel and zirconium lattices upon temperature increase or the application of uniaxial load by means of molecular-dynamics simulation of a model system based on an n-body potential. The behavior of the amorphous region has been investigated as a function of the load intensity and duration. The system reacts upon uniaxial load application with the growth of the amorphous interface. This has been related to the structural change occurring in the glassy region in the form of a density variation consequent to the introduction of excess free volume. These findings are qualitatively consistent with the current hypothesis invoked to explain diffusion and growth of interfacial amorphous regions formed upon load application on bulk diffusion couples

    Advanced services for critical infrastructures protection

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    In this paper an overview of the first results of FP7 CIPRNet project is presented. Particularly, we demonstrate CIPRNet services for critical infrastructure protection (CIP) stakeholders. The role of the proposed services is to support decisions in the CIP domain. Moreover, those services are expected to serve as the underpinnings for the European Infrastructures Simulation and Analysis Centre (EISAC) which, similarly to the US NISAC, should provide operational services on CIP, for the benefits of CI operators, stakeholders and the Public Authorities committed to CIP

    Molecular-dynamics calculations of thermodynamic properties of metastable alloys

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    In order to improve our current understanding of the microscopic structure of metastable alloys of immiscible elements such as Ag-Cu and Co-Cu, the Helmholtz free energy of several microstructures based on an fcc unit cell has been calculated and compared with that of a reference state. The microstructures considered for the free energy calculations at fixed volume are (1) a structure formed by alternating layers of fixed thickness of metal 1 and metal 2 separated by coherent interfaces; (2) an atomically disordered solid solution; (3) a structure comprising a random distribution of elemental cubic grains separated by coherent interfaces. Numerical results show that the Helmholtz free energy of structure (3) decreases with increasing grain size and that its value calculated for a sufficiently large grain size approaches the free energy of structure (1). Further molecular-dynamics simulations for the Ag-Cu system have allowed the calculation of the enthalpy at the equilibrium volume of several microstructures including some of those listed above. A comparison of the calculated values of the enthalpy with the heat release observed experimentally allows the advancement of an hypothesis concerning the reaction path and the structure of the equiatomic Ag-Cu alloy obtained by ball milling

    Towards A Decision Support System For Consequence Analysis Of Flooding On Critical Infrastructure

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    The flooding of the rivers Danube and Elbe caused: dozens of deaths; damaged bridges, streets, dams, railway lines and houses; outages of electrical power, drinking water supply, fixed and mobile telecommunication, water level gauges and purification plants; and crop shortfall. The analysis of the events and emergency response actions exposed flaws in preparedness and the understanding of emergency responders of the need to protect critical infrastructure. For instance, water level gauges failed, flood models for extreme amounts of water were flawed, emergency call numbers became unreachable and first responders could not communicate. As a consequence, protection and evacuation measures could not be planned properly, and the recovery and restoration process took long. The project Critical Infrastructure Preparedness and Resiliance Research Network develops a decision support system (DSS). Within this decision support critical infrastructure simulators are linked with simulators of external threats for critical infrastructure. Analysis tools supply real-time or near real-time data for consequence analysis for different courses of action. This provides the Emergency Manager with a comprehensive assessment of the behaviour of critical infrastructure under severe perturbations (produced by the loss of one or more elements in one or more Infrastructures). In the study area at the Rhine in the Dutch-German border area different dike rings with different safety levels are present. In case of high water, emergency managers have different options to manage the flood, for instance one dik ring can be flooded to prevent dike breaks further downstream. We show cascading effects of different flooding scenarios on power grids, telecommunications and drinking water infrastructure, logistics and transport

    Modeling Resilience in Electrical Distribution Networks

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    Electrical distribution networks deliver a fundamental service to citizens. However, they are still highly vulnerable to natural hazards as well as to cyberattacks; therefore, additional commitment and investments are needed to foster their resilience. Toward that, this paper presents and proposes the use of a complex simulation model, called reconfiguration simulator (RecSIM), enabling to evaluate the effectiveness of resilience enhancement strategies for electric distribution networks and the required resources to implement them. The focus is, in particular, on one specific attribute of resilience, namely, the readiness, i.e., the promptness and efficiency to recover the service functionality after a crisis event by managing and deploying the available resources rapidly and effectively. RecSIM allows estimating how and to what extent technological, topological, and management issues might improve electrical distribution networks’ functionality after the occurrence of accidental faults, accounting for interdependency issues and reconfiguration possibilities. The viability of implementing RecSIM on a real and large urban network is showcased in the paper with reference to the study case of the electrical distribution network (EDN) of Rome city

    Integrating Resilience in Time-based Dependency Analysis: A Large-Scale Case Study for Urban Critical Infrastructures

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    As critical systems shall withstand different types of perturbations affecting their functionalities and their service level, resilience is a very important requirement. Especially in an urban critical infrastructures where the occurrence of natural events may influence the state of other dependent infrastructures from various different sectors, the overall resilience of such infrastructures against large scale failures is even more important. When a perturbation occurs in a system, the quality (level) of the service provided by the affected system will be reduced and a recovery phase will be triggered to restore the system to its normal operation level. According to the implemented recovery controls, the restoration phase may follow a different growth model. This paper extends a previous time-based dependency risk analysis methodology by integrating and assessing the effect of recovery controls. The main goal is to dynamically assess the evolution of recovery over time, in order to identify how the expected recovery plans will eventually affect the overall risk of the critical paths. The proposed recovery-aware time-based dependency analysis methodology was integrated into the CIPCast Decision Support System that enables risk forecast due to natural events to identify vulnerable and disrupted assets (e.g., electric substations, telecommunication components) and measure the expected risk paths. Thus, CIPCast can be valuable to Critical Infrastructure Operators and other Emergency Managers involved in a crisis assessment to evaluate the effect of natural and anthropic threats affecting critical assets and plan proper countermeasures to reduce the overall risk of degradation of services. The proposed methodology is evaluated in a real scenario, which utilizes several infrastructures and Points of Interest of the city of Rome

    A comprehensive system for semantic spatiotemporal assessment of risk in urban areas

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    AbstractRisk assessment of urban areas aims at limiting the impact of harmful events by increasing awareness of their possible consequences. Qualitative risk assessment allows to figure out possible risk situations and to prioritize them, whereas quantitative risk assessment is devoted to measuring risks from data, in order to improve preparedness in case of crisis situations. We propose an automatic approach to comprehensive risk assessment. This leverages on a semantic and spatiotemporal representation of knowledge of the urban area and relies on a software system including: a knowledge base; two components for quantitative and qualitative risk assessments, respectively; and a WebGIS interface. The knowledge base consists of the TERMINUS domain ontology, to represent urban knowledge, and of a geo‐referenced database, including geographical, environmental and urban data as well as temporal data related to the levels of operation of city services. CIPcast DSS is the component devoted to quantitative risk assessment, and WS‐CREAM is the component supporting qualitative risk assessment based on computational creativity techniques. Two case studies concerning the city of Rome (Italy) show how this approach can be used in a real scenario for crisis preparedness. Finally, we discuss issues related to plausibility of risks and objectivity of their assessment
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