2,427 research outputs found
Infrastructure network vulnerability
The work presented in this paper aims to propose a methodology of analyzing infrastructure network vulnerability in the field of prevention or reduction of the natural disaster consequences. After a state of the art on vulnerability models in the academic literature, the various vulnerability factors are classified and discussed. Eventually, a general model of vulnerability analysis including societal parameters is presented
Using Space Syntax For Estimation Of Potential Disaster Indirect Economic Losses
The study of applicable network measures shows that Normalised Angular Choice can be used as criteria for selecting alternatives for minimizing indirect costs caused by road network damages. At the same time, this methodology cannot be used for monetizing indirect costs or identifying losses in different economic sectors. The study approach does not contradict the main theoretical approaches and it gives new opportunities for research on disasters recovery
A methodology to improve the assessment of vulnerability on the maritime supply chain of energy
International audienceThe globalization of trade is due to the transportation possibilities and the standardization (containerization of freight). The dependency of the economy to the sea and to the merchant navy has increase this last decade. This process forms a worldwide maritime network between the different locations of production and consumption. This network, representing between 80 % and 90% of world traffic is a major economic concern, including freight distribution, raw materials or energy. Rodrigue demonstrates[1] the economic dependency of energy is increasing in the industrialized countries (North America, Europe, East Asia). The inter-regional trade of oil was 31 million bbl/day in 2002 and is expected to grow up to 57 bbl/day in 2030 [2]. Most of the international traffic use a maritime way, where may occur disruptions. For example, the Suez crisis (1956-1957) caused a closure of the canal, reducing the throughput capacity of transportation. This disruption cost a 2 millions of barrels lost per day. This article focuses on vulnerability of the energy supply, and proposes a methodology to formalize and assess the vulnerability of the network by taking into account the spatial structure of maritime territories
Potentialities of Complex Network Theory Tools for Urban Drainage Networks Analysis
Urban drainage networks (UDNs) represent important infrastructures to protect and maintain community health and safety. For these reasons, technicians and researcher are focusing more and more on topics related to vulnerability, resilience and monitoring for controlling illicit intrusions, contaminant and pathogenic spread. In the last years the complex network theory (CNT) is attracting attention as a new, useful and structured approach to analyze urban systems. The aim of this work is to evaluate potentialities of CNT approaches for UDNs vulnerability assessment and monitoring system planning. Limits and potentialities of applicability of CNT tools to UDNs are first provided evaluating the performances of standard centrality metrics. Then, it is proposed the use of tailored metrics embedding prior information, as intrinsic relevance of each node and pipe flow direction, which derive from the Horton's hierarchy and geometric data (pipe slope), respectively, without performing hydraulic simulations. The analysis is applied on two schematic literature networks of different complexity and to a real case-study. The results suggest that vulnerability/resilience, monitoring design, contaminant and pathogenic spreads can be effectively analyzed using tailored metrics. Therefore, the proposed approach represents a complementary tool respect the more complex and computationally expensive methodologies and it is particular useful for large complex networks
Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems
Critical infrastructure systems must be both robust and resilient in order to
ensure the functioning of society. To improve the performance of such systems,
we often use risk and vulnerability analysis to find and address system
weaknesses. A critical component of such analyses is the ability to accurately
determine the negative consequences of various types of failures in the system.
Numerous mathematical and simulation models exist which can be used to this
end. However, there are relatively few studies comparing the implications of
using different modeling approaches in the context of comprehensive risk
analysis of critical infrastructures. Thus in this paper, we suggest a
classification of these models, which span from simple topologically-oriented
models to advanced physical flow-based models. Here, we focus on electric power
systems and present a study aimed at understanding the tradeoffs between
simplicity and fidelity in models used in the context of risk analysis.
Specifically, the purpose of this paper is to compare performances measures
achieved with a spectrum of approaches typically used for risk and
vulnerability analysis of electric power systems and evaluate if more
simplified topological measures can be combined using statistical methods to be
used as a surrogate for physical flow models. The results of our work provide
guidance as to appropriate models or combination of models to use when
analyzing large-scale critical infrastructure systems, where simulation times
quickly become insurmountable when using more advanced models, severely
limiting the extent of analyses that can be performed
Utility-service provision as an example of a complex system
Utilityâservice provision is a process in which products are transformed by appropriate devices into services satisfying human needs and wants. Utility products required for these transformations are usually delivered to households via separate infrastructures, i.e., real-world networks such as, e.g., electricity grids and water distribution systems. owever, provision of utility products in appropriate quantities does not itself guarantee hat the required services will be delivered because the needs satisfaction task requires not only utility products but also fully functional devices. Utility infrastructures form complex networks and have been analyzed as such using complex network theory. However, little research has been conducted to date on integration of utilities and associated services
within one complex network. This paper attempts to fill this gap in knowledge by modelling utilityâservice provision within a household with a hypergraph in which products and services are represented with nodes whilst devices are hyperedges
spanning between them. Since devices usually connect more than two nodes, a
standard graph would not suffice to describe utilityâservice provision problem
and therefore a hypergraph was chosen as a more appropriate representation
of the system. This paper first aims to investigate the properties of hypergraphs,
such as cardinality of nodes, betweenness, degree distribution, etc. Additionally,
it shows how these properties can be used while solving and optimizing utilityâ
service provision problem, i.e., constructing a so-called transformation graph. The
transformation graph is a standard graph in which nodes represent the devices,
storages for products, and services, while edges represent the product or service
carriers. Construction of different transformation graphs to a defined utilityâ
service provision problem is presented in the paper to show how the methodology
is applied to generate possible solutions to provision of services to households
under given local conditions, requirements and constraints
Power Grid Network Evolutions for Local Energy Trading
The shift towards an energy Grid dominated by prosumers (consumers and
producers of energy) will inevitably have repercussions on the distribution
infrastructure. Today it is a hierarchical one designed to deliver energy from
large scale facilities to end-users. Tomorrow it will be a capillary
infrastructure at the medium and Low Voltage levels that will support local
energy trading among prosumers. In our previous work, we analyzed the Dutch
Power Grid and made an initial analysis of the economic impact topological
properties have on decentralized energy trading. In this paper, we go one step
further and investigate how different networks topologies and growth models
facilitate the emergence of a decentralized market. In particular, we show how
the connectivity plays an important role in improving the properties of
reliability and path-cost reduction. From the economic point of view, we
estimate how the topological evolutions facilitate local electricity
distribution, taking into account the main cost ingredient required for
increasing network connectivity, i.e., the price of cabling
Vulnerability analysis in complex networks under a flood risk reduction point of view
The measurement and mapping of transportation network vulnerability to natural hazards constitute subjects of global interest for a sustainable development agenda and as means of adaptation to climate change. During a flood, some elements of a transportation network can be affected, causing the loss of lives. Furthermore, impacts include damage to vehicles, streets/roads, and other logistics services - sometimes with severe economic consequences. The Network Science approach may offer a valuable perspective considering one type of vulnerability related to network-type critical infrastructures: the topological vulnerability. The topological vulnerability index associated with an element is defined as reducing the networkâs average efficiency due to removing the set of edges related to that element. In this paper, we present the results of a systematic literature overview and a case study applying the topological vulnerability index for the highways in Santa Catarina (Brazil). We produce a map considering that index and areas susceptible to urban floods and landslides. Risk knowledge, combining hazard and vulnerability, is the first pillar of an Early Warning System and represents an important tool for stakeholders of the transportation sector in a disaster risk reduction agenda.Peer Reviewe
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