17 research outputs found

    Wheel maintenance in rolling stock:safety challenges in the defect detection process

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    The proper and timely maintenance of railway rolling stock is essential for the safety of railway operations. Inaccurate inspection can lead to inadequate repair of defects and to great safety challenges in respect to the entire railway system. The detection and repair of any defect, such as cracks, in the wheels prior to a failure can significantly reduce train derailments and improved operational performance. This paper examines the wheel maintenance process in maintenance depots in the Netherlands on the basis of literature review, observations and interviews. First, it highlights various detection methods, including the risks of the incorrect detection of a flawed wheel profile. This paper introduces a flowchart as a concise illustration of the maintenance process; that is, both the detection and treatment of defects. With this in hand, the authors, as well as anyone involved in maintenance, are able to identify the points where the process is vulnerable and may be prone to incidents/accidents. Based on this procedure, improvements to the current wheel maintenance process can be proposed. The method that the flowchart is based on is also presented herein, along with the findings obtained throughout its step

    NDM-515: AN ORIGINAL MODEL OF INFRASTRUCTURE SYSTEM RESILIENCE

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    Infrastructure systems of transportation, water supply, telecommunications, power supply, etc. are not isolated but highly interconnected and mutually coupled. Infrastructure interdependences can increase system vulnerability and produce cascading failures at the regional or national scales. Taking the advantage of network theory structure analysis, this paper models street, water supply network, power grid and information infrastructure as network layers that are integrated into a multilayer network. The infrastructure interdependences are detailed using five basic dependence patterns of network fundamental elements. Definitions of dynamic cascading failures and recovery mechanisms of infrastructure systems are also established. The main focus of the paper is introduction of a new infrastructure network resilience measure capable of addressing infrastructure system as well as network component (layer) interdependences. The new measure is based on infrastructure network performance, proactive infrastructure network resistance capacity and reactive infrastructure network recovery capacity. With three resilience features and corresponding network properties develops paper, this the of dynamic space new quantitative measure -time resilience and a resilience simulation model resilience and network properties three dimensions of use for infrastructure network assessments. The resilience model is applicable to any type of infrastructure and its application can improve the infrastructure planning, design and maintenance decision making

    Full Paper: Digital Resilience in Critical Infrastructures: A Systematic Literature Review

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    In times of disruptive events, effective response by organizations, critical systems, and society is paramount. The response process involves pre-event preparation, impact absorption, and system restoration, which together represent the concept of resilience. Critical infrastructures (CI) are essential to the functioning of society and require a high level of resilience to ensure that they can withstand and quickly recover from disruptive events. With the incorporation of Information Systems (IS) into CI, there is a need to study Digital Resilience to identify potential risks and develop strategies to mitigate them effectively. In this research, we conducted a Systematic Literature Review on Digital Resilience to understand its scope, and classified articles based on their scope, resilience dimensions, and phases they address, as well as interdependence between systems. We aim to contribute to the scientific understanding of Digital Resilience by analyzing existing gaps and proposing possible future research directions. This study provides an overview of the current state-of-the-art, the types of research conducted, and the resulting artifacts. Additionally, it introduces a new area of focus within the field of resilience: Digital Resilience

    A novel "resilience viewpoint" to aid in engineering resilience in systems of systems (SoS)

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    Designing evolutionary systems to meet stakeholder expectations on safety, reliability and overall resilience is of great importance in an age of interconnectivity and high dependency systems. With incidents and disruptions becoming more frequent in recent years, the requirement for systems to demonstrate high levels of resilience given the economic, political and temporal dimensions of complexity, resilience is of great significance today. Systemic resilience is of high importance at the global level. Therefore, the role of the system engineer and architect is becoming more demanding due to the need to consider requirements from a broader range of stakeholders and to implement them into early conceptual designs. The early modeling process of all systems is common ground for most engineering projects, creating an architecture to both understand a system and to design future iterations by applying model-based processes has become the norm. With the concept of systems-ofsystems (SoS) becoming common language across multiple engineering domains, model-based systems engineering techniques are evolving hand-in-hand to provide a paradigm to better analyse current and future SoS. The intrinsic characteristics of the constituent systems that make up the SoS make the challenge of designing and maintaining the reliability and resilience of a systems extremely difficult. This paper proposes a novel viewpoint, within an architecture framework (based around DoDAF, MoDAF and UPDM) to aid systems architects explore and design resilient SoS. This is known as the Resilience Viewpoint. Much of the research in the area is focussed on critical infrastructure (CI), looking at telecommunication networks, electric grid, supply networks etc, and little has been done on a generalizable tool for SoS architecture analysis, especially using existing modeling languages. Here, the application of the ‘Resilience Viewpoint’ is demonstrated using a case study from an integrated water supply system of systems, to portray its potential analytical capabilities

    Technology-related disasters:a survey towards disaster-resilient software defined networks

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    Resilience against disaster scenarios is essential to network operators, not only because of the potential economic impact of a disaster but also because communication networks form the basis of crisis management. COST RECODIS aims at studying measures, rules, techniques and prediction mechanisms for different disaster scenarios. This paper gives an overview of different solutions in the context of technology-related disasters. After a general overview, the paper focuses on resilient Software Defined Networks

    A Data-Analytics Approach for Enterprise Resilience

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    © 2001-2011 IEEE. Enterprise resilience plays an important role to prevent business services from disruptions caused by human-induced disasters such as failed change implementations and software bugs. Traditional expert-centric approach has difficulty to maintain continued critical business functions because the disasters can often only be handled after their occurrence. This paper introduces a data-analytics approach, which leverages system monitoring data for the enterprise resilience. With the power of data mining and machine learning techniques, we build an intelligent business analytics system to detect the potential disruptions proactively, and to assist the operational team for enterprise resilience enhancement. We demonstrate the effectiveness of our approach on a real enterprise system monitoring dataset in simulation

    Towards the design of resilient waste-to-energy systems using Bayesian networks

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    The concept of resilience has emerged from various domains to address how systems, people and organizations can handle uncertainty. This paper presents a method to improve the resilience of an engineering system by maximizing the system economic lifecycle value, as measured by Net Present Value, under uncertainty. The method is applied to a Waste-to-Energy system based in Singapore and the impact of combining robust and flexible design strategies to improve resilience are discussed. Robust strategies involve optimizing the initial capacity of the system while Bayesian Networks are implemented to choose the flexible expansion strategy that should be deployed given the current observations of demand uncertainties. The Bayesian Network shows promise and should be considered further where decisions are more complex. Resilience is further assessed by varying the volatility of the stochastic demand in the simulation. Increasing volatility generally made the system perform worse since not all demand could be converted to revenue due to capacity constraints. Flexibility shows increased value compared to a fixed design. However, when the system is allowed to upgrade too often, the costs of implementation negates the revenue increase. The better design is to have a high initial capacity, such that there is less restriction on the demand with two or three expansions.</jats:p

    Network science based quantification of resilience demonstrated on the Indian Railways Network

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    The structure, interdependence, and fragility of systems ranging from power grids and transportation to ecology, climate, biology and even human communities and the Internet, have been examined through network science. While the response to perturbations has been quantified, recovery strategies for perturbed networks have usually been either discussed conceptually or through anecdotal case studies. Here we develop a network science-based quantitative methods framework for measuring, comparing and interpreting hazard responses and as well as recovery strategies. The framework, motivated by the recently proposed temporal resilience paradigm, is demonstrated with the Indian Railways Network. The methods are demonstrated through the resilience of the network to natural or human-induced hazards and electric grid failure. Simulations inspired by the 2004 Indian Ocean Tsunami and the 2012 North Indian blackout as well as a cyber-physical attack scenario. Multiple metrics are used to generate various recovery strategies, which are simply sequences in which system components should be recovered after a disruption. Quantitative evaluation of recovery strategies suggests that faster and more resource-effective recovery is possible through network centrality measures. Case studies based on two historical events, specifically the 2004 Indian Ocean tsunami and the 2012 North Indian blackout, and a simulated cyber-physical attack scenario, provides means for interpreting the relative performance of various recovery strategies. Quantitative evaluation of recovery strategies suggests that faster and more resource-effective restoration is possible through network centrality measures, even though the specific strategy may be different for sub-networks or for the partial recovery

    Reframing Resilience: Equitable Access to Essential Services

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156467/2/risa13492.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156467/1/risa13492_am.pd
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