PSAM 16 - Paper Overview

PSAM 16 Conference Paper Overview

Welcome to the PSAM 16 Conference paper and speaker overview page.

Lead Author: Behrooz Ashrafi Co-author(s): Masoud Naseri, masoud.naseri@uit.no

Resilience of a transportation network: Importance of vulnerable nodes
Modern societies rely on critical infrastructures (CIs) for their daily functions. Transportation infrastructure (TI) is one of the most crucial of CIs which is essential for a functioning modern society. Along with the normal usage and importance of TIs, most CI sectors are dependent on TI to function effectively; Also, in case of a crisis (natural or man-made) TIs are essential for post-crisis recovery. Resilience engineering is gradually moving towards becoming one of the major tools in CI management. Resilience can be defined as the ability of a system to resist disruptions and adapt to them and in case of a failure recover from them quickly. Resilience concept can be divided into four elements, robustness/redundancy, rapidity, resourcefulness, and adaptability. Although these elements are intertwined, they can be assessed separately. TI assessment has been tackled with different modelling approaches in the available literatures. One of the most common approaches that has been used in these studies is network theory that has proven to be an effective tool for modelling and analyzing transportation networks (TNs) due to its flexibility and simplicity when concerning the large number of connections (roads) between elements in a TN. In network theoretical approaches cities or intersections are denoted by nodes. and links are denoted by edges that connect such nodes. A variety of different metrics is being utilized for modelling TNs. These metrics have two main types, generic or functional. Generic metrics describe the network structure (e.g., degree centrality, betweenness centrality, connectivity, etc.). Functional metrics describe the attributes of a TN (e.g., length of path, travel time, traffic flow, reliability of each path, population density of nodes/cities, network topology, etc.). Most of the available literature on TN assessment have neglected the importance of vulnerable nodes (VN), which have fewer outgoing edges relative to the other nodes. These VNs are essential in resilience assessment of a TN. In case of an emergency, the probability of VNs isolation (separation from the network) is high. The isolation of nodes, in turn cuts of traffic flow in and out of the isolated node, which can be disastrous for the population of that node. This paper presents a framework for assessing the resilience of TNs while focusing on the robustness/redundancy aspect of resilience. This framework uses network theory and takes into account the concept of independent pathways (i.e., a set of all the pathways connecting each node-pair that do not share any identical edge), network topology, redundancies in the network, traffic flow, reliabilities of edges, vulnerabilities in nodes and the importance of the hub nodes (also critical nodes). This paper argues that in resilience assessment for transportation networks, vulnerability of nodes is crucial and needs to be considered with extra emphasis when analyzing the network. In this framework a score system is also developed for comparing different failure scenarios (edge failure combinations) to discover the most critical elements (nodes and edges) in the network. The scoring system is employed for the whole network and the individual nodes.

Resilience of a transportation network: Importance of vulnerable nodes

Modern societies rely on critical infrastructures (CIs) for their daily functions. Transportation infrastructure (TI) is one of the most crucial of CIs which is essential for a functioning modern society. Along with the normal usage and importance of TIs, most CI sectors are dependent on TI to function effectively; Also, in case of a crisis (natural or man-made) TIs are essential for post-crisis recovery. Resilience engineering is gradually moving towards becoming one of the major tools in CI management. Resilience can be defined as the ability of a system to resist disruptions and adapt to them and in case of a failure recover from them quickly. Resilience concept can be divided into four elements, robustness/redundancy, rapidity, resourcefulness, and adaptability. Although these elements are intertwined, they can be assessed separately. TI assessment has been tackled with different modelling approaches in the available literatures. One of the most common approaches that has been used in these studies is network theory that has proven to be an effective tool for modelling and analyzing transportation networks (TNs) due to its flexibility and simplicity when concerning the large number of connections (roads) between elements in a TN. In network theoretical approaches cities or intersections are denoted by nodes. and links are denoted by edges that connect such nodes. A variety of different metrics is being utilized for modelling TNs. These metrics have two main types, generic or functional. Generic metrics describe the network structure (e.g., degree centrality, betweenness centrality, connectivity, etc.). Functional metrics describe the attributes of a TN (e.g., length of path, travel time, traffic flow, reliability of each path, population density of nodes/cities, network topology, etc.). Most of the available literature on TN assessment have neglected the importance of vulnerable nodes (VN), which have fewer outgoing edges relative to the other nodes. These VNs are essential in resilience assessment of a TN. In case of an emergency, the probability of VNs isolation (separation from the network) is high. The isolation of nodes, in turn cuts of traffic flow in and out of the isolated node, which can be disastrous for the population of that node. This paper presents a framework for assessing the resilience of TNs while focusing on the robustness/redundancy aspect of resilience. This framework uses network theory and takes into account the concept of independent pathways (i.e., a set of all the pathways connecting each node-pair that do not share any identical edge), network topology, redundancies in the network, traffic flow, reliabilities of edges, vulnerabilities in nodes and the importance of the hub nodes (also critical nodes). This paper argues that in resilience assessment for transportation networks, vulnerability of nodes is crucial and needs to be considered with extra emphasis when analyzing the network. In this framework a score system is also developed for comparing different failure scenarios (edge failure combinations) to discover the most critical elements (nodes and edges) in the network. The scoring system is employed for the whole network and the individual nodes.

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Author and Presentation Info

Lead Author Name: Behrooz Ashrafi (behrooz.ashrafi@uit.no)

Bio:

Country: Norway
Company: UiT, The arctic university of Norway
Job Title: PhD Student

PSAM 16 Conference Paper Overview

Welcome to the PSAM 16 Conference paper and speaker overview page.

Paper BE107 Preview

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