25,761 research outputs found
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Stochastic modelling of the effects of interdependencies between critical infrastructure
An approach to Quantitative Interdependency Analysis, in the context of Large Complex Critical Infrastructures, is presented in this paper. A Discrete stateâspace, Continuousâtime, Stochastic Process models the operation of critical infrastructure, taking interdependencies into account. Of primary interest are the implications of both model detail (that is, level of model abstraction) and model parameterisation for the study of dependencies. Both of these factors are observed to affect the distribution of cascadeâsizes within and across infrastructure
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Current capabilities, requirements and a proposed strategy for interdependency analysis in the UK
The UK government recently commissioned a research study to identify the state-of-the-art in Critical Infrastructure modelling and analysis, and the government/industry requirements for such tools and services. This study (Cetifs) concluded with a strategy aiming to bridge the gaps between the capabilities and requirements, which would establish interdependency analysis as a commercially viable service in the near future. This paper presents the findings of this study that was carried out by CSR, City University London, Adelard LLP, a safety/security consultancy and Cranfield University, defense academy of the UK
Australian commercial-critical infrastructure management protection
Secure management of Australia\u27s commercial critical infrastructure presents ongoing challenges to owners and the government. Although managed via a high-level information sharing collaboration of government and business, critical infrastructure protection is further complicated by the lack of a lower-level scalable model exhibiting its various levels, sectors and sub-sectors. This research builds on the work of Marasea (2003) to establish a descriptive critical infrastructure model and also considers the influence and proposed modelling of critical infrastructure dependency inter-relationships.<br /
Characterizing the Role of Power Grids in Internet Resilience
Among critical infrastructures, power grids and communication infrastructure
are identified as uniquely critical since they enable the operation of all
other sectors. Due to their vital role, the research community has undertaken
extensive efforts to understand the complex dynamics and resilience
characteristics of these infrastructures, albeit independently. However, power
and communication infrastructures are also interconnected, and the nature of
the Internet's dependence on power grids is poorly understood.
In this paper, we take the first step toward characterizing the role of power
grids in Internet resilience by analyzing the overlap of global power and
Internet infrastructures. We investigate the impact of power grid failures on
Internet availability and find that nearly of the public Internet
infrastructure components are concentrated in a few () power grid failure
zones. More importantly, power grid dependencies severely limit the number of
disjoint availability zones of cloud providers. When dependency on grids
serving data center locations is taken into account, the number of isolated AWS
Availability Zones reduces from 87 to 19. Building upon our findings, we
develop NetWattZap, an Internet resilience analysis tool that generates power
grid dependency-aware deployment suggestions for Internet infrastructure and
application components, which can also take into account a wide variety of user
requirements
Model Based Development of Quality-Aware Software Services
Modelling languages and development frameworks give support for functional and structural description of software architectures. But quality-aware applications require languages which allow expressing QoS as a first-class concept during architecture design and service composition, and to extend existing tools and infrastructures adding support for modelling, evaluating, managing and monitoring QoS aspects. In addition to its functional behaviour and internal structure, the developer of each service must consider the fulfilment of its quality requirements. If the service is flexible, the output quality depends both on input quality and available resources (e.g., amounts of CPU execution time and memory). From the software engineering point of view, modelling of quality-aware requirements and architectures require modelling support for the description of quality concepts, support for the analysis of quality properties (e.g. model checking and consistencies of quality constraints, assembly of quality), tool support for the transition from quality requirements to quality-aware architectures, and from quality-aware architecture to service run-time infrastructures. Quality management in run-time service infrastructures must give support for handling quality concepts dynamically. QoS-aware modeling frameworks and QoS-aware runtime management infrastructures require a common evolution to get their integration
Enhancing Infrastructure Resilience Under Conditions of Incomplete Knowledge of Interdependencies
Todayâs infrastructures â such as road, rail, gas, electricity and ICT â are highly interdependent, and may best be viewed
as multi-infrastructure systems. A key challenge in seeking to enhance the resilience of multi-infrastructure systems in
practice relates to the fact that many interdependencies may be unknown to the operators of these infrastructures.
How can we foster infrastructure resilience lacking complete knowledge of interdependencies? In addressing this
question, we conceptualize the situation of a hypothetical infrastructure operator faced with incomplete knowledge of
the interdependencies to which his infrastructure is exposed. Using a computer model which explicitly represents failure
propagations and cascades within a multi-infrastructure system, we seek to identify robust investment strategies on the part
of the operator to enhance infrastructure resilience.
Our results show that a strategy of constructing redundant interdependencies may be the most robust option for a
financially constrained infrastructure operator. These results are specific to the infrastructure configuration tested. However,
the developed model may be tailored to the conditions of real-world infrastructure operators faced with a similar dilemma,
ultimately helping to foster resilient infrastructures in an uncertain world
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