635 research outputs found

    Development of a decision support system through modelling of critical infrastructure interdependencies : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Emergency Management at Massey University, Wellington, New Zealand

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    Critical Infrastructure (CI) networks provide functional services to support the wellbeing of a community. Although it is possible to obtain detailed information about individual CI and their components, the interdependencies between different CI networks are often implicit, hidden or not well understood by experts. In the event of a hazard, failures of one or more CI networks and their components can disrupt the functionality and consequently affect the supply of services. Understanding the extent of disruption and quantification of the resulting consequences is important to assist various stakeholders' decision-making processes to complete their tasks successfully. A comprehensive review of the literature shows that a Decision Support System (DSS) integrated with appropriate modelling and simulation techniques is a useful tool for CI network providers and relevant emergency management personnel to understand the network recovery process of a region following a hazard event. However, the majority of existing DSSs focus on risk assessment or stakeholders' involvement without addressing the overall CI interdependency modelling process. Furthermore, these DSSs are primarily developed for data visualization or CI representation but not specifically to help decision-makers by providing them with a variety of customizable decision options that are practically viable. To address these limitations, a Knowledge-centred Decision Support System (KCDSS) has been developed in this study with the following aims: 1) To develop a computer-based DSS using efficient CI network recovery modelling algorithms, 2) To create a knowledge-base of various recovery options relevant to specific CI damage scenarios so that the decision-makers can test and verify several ‘what-if’ scenarios using a variety of control variables, and 3) To bridge the gap between hazard and socio-economic modelling tools through a multidisciplinary and integrated natural hazard impact assessment. Driven by the design science research strategy, this study proposes an integrated impact assessment framework using an iterative design process as its first research outcome. This framework has been developed as a conceptual artefact using a topology network-based approach by adopting the shortest path tree method. The second research outcome, a computer-based KCDSS, provides a convenient and efficient platform for enhanced decision making through a knowledge-base consisting of real-life recovery strategies. These strategies have been identified from the respective decision-makers of the CI network providers through the Critical Decision Method (CDM), a Cognitive Task Analysis (CTA) method for requirement elicitation. The capabilities of the KCDSS are demonstrated through electricity, potable water, and road networks in the Wellington region of Aotearoa New Zealand. The network performance has been analysed independently and with interdependencies to generate outage of services spatially and temporally. The outcomes of this study provide a range of theoretical and practical contributions. Firstly, the topology network-based analysis of CI interdependencies will allow a group of users to build different models, make and test assumptions, and try out different damage scenarios for CI network components. Secondly, the step-by-step process of knowledge elicitation, knowledge representation and knowledge modelling of CI network recovery tasks will provide a guideline for improved interactions between researchers and decision-makers in this field. Thirdly, the KCDSS can be used to test the variations in outage and restoration time estimates of CI networks due to the potential uncertainty related to the damage modelling of CI network components. The outcomes of this study also have significant practical implications by utilizing the KCDSS as an interface to integrate and add additional capabilities to the hazard and socio-economic modelling tools. Finally, the variety of ‘what-if’ scenarios embedded in the KCDSS would allow the CI network providers to identify vulnerabilities in their networks and to examine various post-disaster recovery options for CI reinstatement projects

    Towards Intelligent Distribution Systems: Solutions for Congestion Forecast and Dynamic State Estimation Based Protection

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    The electrical distribution systems are undergoing drastic changes such as increasing penetration level of distributed renewable energy sources, energy storage, electrification of energy-efficient loads such as heat pumps and electric vehicles, etc., since the last decade, and more changes are expected in the future. These changes pose challenges for the distribution system operators such as increased level of network congestions, voltage variations, as well as protection settings and coordination, etc. These will require the development of new paradigms to operate distribution systems securely, safely, and economically while hosting a large amount of renewable energy sources.First, the thesis proposed a comprehensive assessment framework to assess the distribution system operator’s future-readiness and support them in determining the current status of their network infrastructures, business models, and policies and thus to identify areas for required developments. The analysis for the future-readiness of the three distribution system operators (from France, The Netherlands, and Sweden) using the proposed assessment framework has shown that presently the distribution system operators have a rather small penetration of renewable energy sources in their grids, however, which is expected to increase in the future. The distribution system operators would need investments in flexibilities, novel forecasting techniques, advanced grid control as well as improved protection schemes. The need for the development of new business models for customers and changes in the policy and regulations are also suggested by the analysis. Second, the thesis developed a congestion forecast tool that would support the distribution system operators to forecast and visualize network overloading and voltage variations issues for multiple forecasting horizons ranging from close-to-real time to day-ahead. The tool is based on a probabilistic power flow that incorporates forecasts of production from solar photovoltaic and electricity demand combined with load models along with the consideration of different operating modes of solar photovoltaic inverters to enhance the accuracy. The congestion forecast tool can be integrated into the existing distribution management systems of distribution system operators via an open cross-platform using Codex Smart Edge technology of Atos Worldgrid. The congestion forecast tool has been used in a case study for two real distribution systems (7-bus feeder and 141-bus system). It was demonstrated in the case study that the tool can predict the congestion in the networks with various prediction horizons. The congestion forecast tool would support distribution system operators by forecasting the network congestion and setting up a congestion management plan.Finally, the dynamic state estimation based protection scheme supported by advanced measurement technologies developed within EU project UNITED-GRID has been implemented and validated experimentally at Chalmers power system laboratory. This dynamic state estimation based protection scheme has a strong advantage over the traditional protection scheme as it does not require any relay settings and coordination which can overcome the protection challenges arising in distribution grids with a large amount of renewable energy sources. The results from the validation of the dynamic state estimation based protection scheme at Chalmers laboratory have shown that the fault detection using this scheme has worked properly as expected for an application of the line protection

    The organisational precursors to human automation interaction issues in safety-critical domains: the case of an automated alarm system from the air traffic management domain

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    Much has been written about the side effects of automation in complex safety-critical domains, such as air traffic management, aviation, nuclear power generation, and healthcare. Here, human factors and safety researchers have long acknowledged that the potential of automation to increase cost-effectiveness, quality of service and safety, is accompanied by undesired side effects or issues in human automation interaction (HAI). Such HAI issues may introduce the potential for increased confusion, uncertainty, and frustration amongst sharp end operators, i.e. the users of automation. These conditions may result in operators to refuse to use the automation, in impaired ability of operators to control the hazardous processes for which they are responsible, and in new, unintended paths to safety failure. The present thesis develops a qualitative framework of the organisational precursors to HAI issues (OPHAII) that can be found in safety-critical domains. Organisational precursors denote those organisational and managerial conditions that, although distant in time and space from the operational environment, may actually influence the quality of HAI found there. Such precursors have been extensively investigated by organisational safety (OS) scholars in relation to the occurrence of accidents and disasters—although not HAI issues. Thus, the framework’s development is motivated by the intent to explore the theoretical gap lying at the intersection between the OS area and the current perspectives on the problem—the human computer interaction (HCI) and the system lifecycle ones. While considering HAI issues as a design problem or a failure in human factors integration and/or safety assurance respectively, both perspectives, in fact, ignore, the organisational roots of the problem. The OPHAII framework was incrementally developed based on three qualitative studies: two successive, historical, case studies coupled with a third corroboratory expert study. The first two studies explored the organisational precursors to a known HAI issue: the nuisance alert problem relative to an automated alarm system from the air traffic management domain. In particular, the first case study investigated retrospectively the organisational response to the nuisance alert problem in the context of the alarm’s implementation and improvement in the US between 1977 and 2006. The second case study has a more contemporary focus, and examined at the organisational response to the same problem within two European Air Navigation Service Providers between 1990 and 2010. The first two studies produced a preliminary version of the framework. The third study corroborated and refined this version by subjecting it to the criticism from a panel of 11 subject matter experts. The resulting framework identifies three classes of organisational precursors: (i) the organisational assumptions driving automation adoption and improvement; (2) the availability of specific organisational capabilities for handling HAI issues; and (3) the control of implementation quality at the boundary between the service provider and the software manufacturer. These precursors advance current understanding of the organisational factors involved in the (successful and problematic) handling of HAI issues within safety-critical service provider organisations. Its dimensions support the view that HAI issues can be seen as and organisational phenomenon—an organisational problem that can be the target of analysis and improvements complementary to those identified by the HCI and the system lifecycle perspectives

    The New Decade of Construction Contracts: Technological and Climate Considerations for Owners, Designers, and Builders

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    In the next decade, the construction industry faces two intertwined risks: implementation of new technologies and the impacts of climate change. Those overlapping risks will present both practical and legal issues for design professionals, developers, builders, legislators, and the public at large. Although the average participant in the construction industry may not think twice about the emergence or adoption of new technologies, or the effect of climate change on the completed project, those issues present nuanced legal implications. Construction projects and their contracts must adapt. While companies seek to implement new technologies, provide sustainable products, optimize project systems, and maximize productivity, those companies should also be aware of the risks they might face. Such considerations are especially important where the human environment and legal landscape are continuously changing

    Tackling the Challenges of Information Security Incident Reporting: A Decentralized Approach

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    Information security incident under-reporting is unambiguously a business problem, as identified by a variety of sources, such as ENISA (2012), Symantec (2016), Newman (2018) and more. This research project identified the underlying issues that cause this problem and proposed a solution, in the form of an innovative artefact, which confronts a number of these issues. This research project was conducted according to the requirements of the Design Science Research Methodology (DSRM) by Peffers et al (2007). The research question set at the beginning of this research project, probed the feasible formation of an incident reporting solution, which would increase the motivational level of users towards the reporting of incidents, by utilizing the positive features offered by existing solutions, on one hand, but also by providing added value to the users, on the other. The comprehensive literature review chapter set the stage, and identified the reasons for incident underreporting, while also evaluating the existing solutions and determining their advantages and disadvantages. The objectives of the proposed artefact were then set, and the artefact was designed and developed. The output of this development endeavour is “IRDA”, the first decentralized incident reporting application (DApp), built on “Quorum”, a permissioned blockchain implementation of Ethereum. Its effectiveness was demonstrated, when six organizations accepted to use the developed artefact and performed a series of pre-defined actions, in order to confirm the platform’s intended functionality. The platform was also evaluated using Venable et al’s (2012) evaluation framework for DSR projects. This research project contributes to knowledge in various ways. It investigates blockchain and incident reporting, two domains which have not been extensively examined and the available literature is rather limited. Furthermore, it also identifies, compares, and evaluates the conventional, reporting platforms, available, up to date. In line with previous findings (e.g Humphrey, 2017), it also confirms the lack of standard taxonomies for information security incidents. This work also contributes by creating a functional, practical artefact in the blockchain domain, a domain where, according to Taylor et al (2019), most studies are either experimental proposals, or theoretical concepts, with limited practicality in solving real-world problems. Through the evaluation activity, and by conducting a series of non-parametric significance tests, it also suggests that IRDA can potentially increase the motivational level of users towards the reporting of incidents. This thesis describes an original attempt in utilizing the newly emergent blockchain technology, and its inherent characteristics, for addressing those concerns which actively contribute to the business problem. To the best of the researcher’s knowledge, there is currently no other solution offering similar benefits to users/organizations for incident reporting purposes. Through the accomplishment of this project’s pre-set objectives, the developed artefact provides a positive answer to the research question. The artefact, featuring increased anonymity, availability, immutability and transparency levels, as well as an overall lower cost, has the potential to increase the motivational level of organizations towards the reporting of incidents, thus improving the currently dismaying statistics of incident under-reporting. The structure of this document follows the flow of activities described in the DSRM by Peffers et al (2007), while also borrowing some elements out of the nominal structure of an empirical research process, including the literature review chapter, the description of the selected research methodology, as well as the “discussion and conclusion” chapter
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