| 1. |
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| 2. |
- Bernardi, S., et al.
(författare)
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Enabling the usage of UML in the verification of railway systems : The DAM-rail approach
- 2013
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Ingår i: Reliability Engineering & System Safety. - : Elsevier. - 0951-8320 .- 1879-0836. ; 120, s. 112-126
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Tidskriftsartikel (refereegranskat)abstract
- The need for integration of model-based verification into industrial processes has produced several attempts to define Model-Driven solutions implementing a unifying approach to system development. A recent trend is to implement tool chains supporting the developer both in the design phase and V&V activities. In this Model-Driven context, specific domains require proper modelling approaches, especially for what concerns RAM (Reliability, Availability, Maintainability) analysis and fulfillment of international standards. This paper specifically addresses the definition of a Model-Driven approach for the evaluation of RAM attributes in railway applications to automatically generate formal models. For this aim we extend the MARTE-DAM UML profile with concepts related to maintenance aspects and service degradation, and show that the MARTE-DAM framework can be successfully specialized for the railway domain. Model transformations are then defined to generate Repairable Fault Tree and Bayesian Network models from MARTE-DAM specifications. The whole process is applied to the railway domain in two different availability studies. © 2013 Elsevier Ltd.
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| 3. |
- Casola, V., et al.
(författare)
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Securing freight trains for hazardous material transportation : A WSN-based monitoring system
- 2012
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Ingår i: International Defense and Homeland Security Simulation Workshop, DHSS 2012, Held at the International Multidisciplinary Modeling and Simulation Multiconference, I3M 2012. - : Caltek s.r.l.. ; , s. 52-59
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Konferensbidrag (refereegranskat)abstract
- In recent years the interest in monitoring infrastructures has spread in many application domains, even because of the number of natural disasters and terrorist attacks. This important activity can be seen in the general context of critical infrastructure protection such as the freight train meant for hazardous materials transportation. The design of these systems must answer to several issues: low-cost, easiness of installation, interoperability of information sources, security mechanisms. The use of wireless sensor networks emerged in this field as a compliant solution to these issues. In this paper we will present a monitoring system that uses heterogeneous WSN to monitor a freight train transporting hazardous materials. The sensors interact through a security platform in order to share different information. We illustrate some details on the architecture and the software application to prove the feasibility of such system on a real scenario by discussing most significant results about measurement parameters and networks performance. Copyright© (2012) by CAL-TEK S.r.l.
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| 4. |
- De Benedictis, A., et al.
(författare)
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Digital Twins for Anomaly Detection in the Industrial Internet of Things : Conceptual Architecture and Proof-of-Concept
- 2023
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Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE Computer Society. - 1551-3203 .- 1941-0050. ; 19:12, s. 11553-11563
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Tidskriftsartikel (refereegranskat)abstract
- Modern cyber-physical systems based on the industrial Internet of Things (IIoT) can be highly distributed and heterogeneous, and that increases the risk of failures due to misbehavior of interconnected components, or other interaction anomalies. In this article, we introduce a conceptual architecture for IIoT anomaly detection based on the paradigms of digital twins (DT) and autonomic computing (AC), and we test it through a proof-of-concept of industrial relevance. The architecture is derived from the current state-of-the-art in DT research and leverages on the MAPE-K feedback loop of AC in order to monitor, analyze, plan, and execute appropriate reconfiguration or mitigation strategies based on the detected deviation from prescriptive behavior stored as shared knowledge. We demonstrate the approach and discuss results by using a reference operational scenario of adequate complexity and criticality within the European Railway Traffic Management System.
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| 5. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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DETECT : A novel framework for the detection of attacks to critical infrastructures
- 2009
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Ingår i: Safety, Reliability and Risk Analysis. - : Taylor & Francis. - 9780415485135 ; , s. 105-112
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Konferensbidrag (refereegranskat)abstract
- Critical Infrastructure Protection (CIP) against potential threats has become a major issue in modern society. CIP involves a set of multidisciplinary activities and requires the adoption of proper protection mechanisms, usually supervised by centralized monitoring systems. This paper presents the motivation, the working principles and the software architecture of DETECT (DEcision Triggering Event Composer & Tracker), a new framework aimed at the automatic and early detection of threats against critical infrastructures. The framework is based on the fact that non trivial attack scenarios are made up by a set of basic steps which have to be executed in a predictable sequence (with possible variants). Such scenarios are identified during Vulnerability Assessment which is a fundamental phase of the Risk Analysis for critical infrastructures. DETECT operates by performing a model-based logical, spatial and temporal correlation of basic events detected by the sensorial subsystem (possibly including intelligent video-surveillance, wireless sensor networks, etc.). In order to achieve this aim, DETECT is based on a detection engine which is able to reason about heterogeneous data, implementing a centralized application of "data fusion". The framework can be interfaced with or integrated in existing monitoring systems as a decision support tool or even to automatically trigger adequate countermeasures.
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| 6. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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Evaluating the Hazardous Failure Rate of majority voting computer architectures by means of Bayesian Network models
- 2007
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Ingår i: Proceedings of the European Safety and Reliability Conference 2007, ESREL 2007 - Risk, Reliability and Societal Safety. - 0415447860 - 9780415447867 ; , s. 1715-1721
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Konferensbidrag (refereegranskat)abstract
- Safety-critical control systems are usually based on majority voters. In order to assess the compliance of these architectures with international safety standards, the probability of the occurrence of unsafe events should be evaluated by developing and analyzing proper formal models. In this paper we demonstrate that a Bayesian Network (BN) model can be used to evaluate the Mean Time Between Hazardous Events (MTBHE) of voting architectures. The proposed modeling approach is applied to a "2 out of 2" ("2002") voter consisting of independent computing units. The results obtained from the analysis of the BN model of the "2002" voter can be easily extended to evaluate the hazardous failure rate of more complex voting architectures (e.g. Triple Modular Redundant architectures, based on a 2003 voting). Within this context, BNs have several advantages over other traditional approaches (e.g. Petri Nets or Markov Chains): the model can be directly derived from the analysis of the flow-chart describing the dynamic of hazardous failures and its evaluation is much more efficient, as BN solving algorithms are non state-based; moreover, sensitivity analyses can be automatically performed by using the available user friendly BN tools . Finally, the proposed BN model is quite general and can be easily adapted and/or extended to suit specific computing architectures and fault models. © 2007 Taylor & Francis Group.
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| 7. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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Modeling of railway logics for reverse enginering, verification and refactoring
- 2011
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Ingår i: International Journal of Safety and Security Engineering. - : WITPress. - 2041-9031 .- 2041-904X. ; 1:1, s. 77-94
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Tidskriftsartikel (refereegranskat)abstract
- Model-based approaches are widespread both in functional and non-functional verification activities of critical computer-based systems. Reverse engineering can also be used to support checks for correctness of system implementation against its requirements. In this paper, we show how a model-based technique, using the Unified Modeling Language (UML), suits the reverse engineering of complex control logics. UML is usually exploited to drive the development of software systems, using an object-oriented and bottom-up approach; however, it can be also used to model legacy non-object-oriented logic processes featuring a clear distinction between data structures and related operations. Our case-study consists in the most important component of the European Railway Traffic Management System/European Train Control System: the Radio Block Center (RBC). The model we obtained from the logic code of the RBC significantly facilitated both structural and behavioral analyses, giving a valuable contribution to the static verification and refactoring of the software under test. © 2011 WIT Press.
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| 8. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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Modeling system reliability aspects of ERTMS/ETCS by fault trees and Bayesian networks
- 2006
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Ingår i: Safety and Reliability for Managing Risk. - London : Taylor & Francis. - 0415416205 - 9780415416207 ; , s. 2675-2683
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Konferensbidrag (refereegranskat)abstract
- Critical control systems require proper techniques to predict their failure rate since early design stages, in order to fulfil dependability requirements and minimize development costs. Bayesian Networks have been shown to be suitable to model system reliability aspects, extending the modeling power of Fault Trees and featuring a better solving efficiency with respect to Petri Nets. In this paper we exploit the Fault Tree and Bayesian Network formalisms in order to perform a hardware reliability analysis of a complex real world case study: the European Railway Traffic Management System/European Train Control System (ERTMS/ETCS). ERTMS/ETCS is a recent standard specification aimed at improving interoperability, performances and dependability of modern railways. An implementation of ERTMS/ETCS is a distributed heterogeneous system with strict reliability requirements. Starting from such requirements and from a reference hardware architecture, we studied system reliability by instantiating models with realistic parameters and performing a series of sensitivity analyses in order to highlight design trade-offs. By evaluating and integrating sub-models using a compositional approach we both obtained several interesting results and showed the effectiveness of a combined use of Fault Trees and Bayesian Networks in dealing with system reliability analyses of train control systems.
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| 9. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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Modelling system reliability aspects of ERTMS/ETCS by fault trees and Bayesian networks
- 2006
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Ingår i: Safety and Reliability for Managing Risk: proceedings of the 15th European Safety and Reliability Conference (ESREL 2006). - 9780415416207 ; , s. 2675-2683
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Konferensbidrag (refereegranskat)abstract
- ERTMS/ETCS is a recent standard specification aimed at improving interoperability, performances and dependability of modern railways. An implementation of ERTMS/ETCS is a distributed heterogeneous system with strict availability requirements. On the basis of such requirements and of the hypothesised system reference architecture, we studied structural availability by instantiating models with realistic reliability parameters and performing a series of sensitivity analyses in order to highlight design trade-offs. By evaluating and integrating sub-models using a compositional approach we both obtained several interesting results and showed the effectiveness of a combined use of Fault Trees and Bayesian Networks in dealing with structural reliability analyses of train control systems.
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| 10. |
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| 11. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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Multiformalism techniques for critical infrastructure modeling
- 2010
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Ingår i: International Journal of System of Systems Engineering. - 1748-0671 .- 1748-068X. ; 2:1, s. 19-37
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes an approach to use multiformalism techniques for critical infrastructure modelling. To this aim, the state of the art of related works on the subject is surveyed and a general scheme for intra and inter infrastructure models is described. Multiformalism approaches allow modellers to adapt the choice of formal languages to the nature, complexity and abstraction layer of the subsystems to be modelled. Another advantage is the possibility of reusing existing dependability models and solvers. Complexity and heterogeneity are managed through modularity, and composition allows for representing structural or functional dependencies. An example model based on a railway infrastructure is used to illustrate the concepts introduced by the paper. Copyright © 2010 Inderscience Enterprises Ltd.
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| 12. |
- Singh, Prasannjeet, et al.
(författare)
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Using log analytics and process mining to enable self-healing in the Internet of Things
- 2022
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Ingår i: Environment Systems and Decisions. - : Springer. - 2194-5403 .- 2194-5411. ; 42:2, s. 234-250
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Tidskriftsartikel (refereegranskat)abstract
- The Internet of Things (IoT) is rapidly developing in diverse and critical applications such as environmental sensing and industrial control systems. IoT devices can be very heterogeneous in terms of hardware and software architectures, communication protocols, and/or manufacturers. Therefore, when those devices are connected together to build a complex system, detecting and fixing any anomalies can be very challenging. In this paper, we explore a relatively novel technique known as Process Mining, which—in combination with log-file analytics and machine learning—can support early diagnosis, prognosis, and subsequent automated repair to improve the resilience of IoT devices within possibly complex cyber-physical systems. Issues addressed in this paper include generation of consistent Event Logs and definition of a roadmap toward effective Process Discovery and Conformance Checking to support Self-Healing in IoT.
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