Outputs (34)

Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations (2023)
Journal Article
Aslansefat, K., Hashemian, M., Walker, M., Akram, M. N., Sorokos, I., & Papadopoulos, Y. (2023). Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations. IEEE Software, https://doi.org/10.1109/MS.2023.3321282

Machine learning is currently undergoing an explosion in capability, popularity, and sophistication. However, one of the major barriers to widespread acceptance of machine learning (ML) is trustworthiness: most ML models operate as black boxes, their... Read More about Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations.

Towards Improving Confidence in Autonomous Vehicle Software: A Study on Traffic Sign Recognition Systems (2021)
Journal Article
Aslansefat, K., Kabir, S., Abdullatif, A., Vasudevan Nair, V., & Papadopoulos, Y. (in press). Towards Improving Confidence in Autonomous Vehicle Software: A Study on Traffic Sign Recognition Systems. Computer,

The application of artificial intelligence (AI) and data-driven decision-making systems in autonomous vehicles is growing rapidly. As autonomous vehicles operate in dynamic environments, the risk that they can face an unknown observation is relativel... Read More about Towards Improving Confidence in Autonomous Vehicle Software: A Study on Traffic Sign Recognition Systems.

Computational Intelligence for Safety Assurance of Cooperative Systems of Systems (2020)
Journal Article
Kabir, S., & Papadopoulos, Y. (2020). Computational Intelligence for Safety Assurance of Cooperative Systems of Systems. Computer, 53(12), 24-34. https://doi.org/10.1109/MC.2020.3014604

Cooperative systems of systems (CSoSs) form a new technological frontier for their enormous economic and societal potentials in various domains. This article presents a novel framework for dynamic safety assurance of CSoSs that integrates design time... Read More about Computational Intelligence for Safety Assurance of Cooperative Systems of Systems.

A Hybrid Modular Approach for Dynamic Fault Tree Analysis (2020)
Journal Article
Kabir, S., Aslansefat, K., Sorokos, I., Papadopoulos, Y., & Konur, S. (2020). A Hybrid Modular Approach for Dynamic Fault Tree Analysis. IEEE Access, 8, 97175-97188. https://doi.org/10.1109/ACCESS.2020.2996643

Over the years, several approaches have been developed for the quantitative analysis of dynamic fault trees (DFTs). These approaches have strong theoretical and mathematical foundations; however, they appear to suffer from the state-space explosion a... Read More about A Hybrid Modular Approach for Dynamic Fault Tree Analysis.

Dynamic reliability assessment of flare systems by combining fault tree analysis and Bayesian networks (2019)
Journal Article
Kabir, S., Taleb-Berrouane, M., & Papadopoulos, Y. (in press). Dynamic reliability assessment of flare systems by combining fault tree analysis and Bayesian networks. Energy Sources, Part A, https://doi.org/10.1080/15567036.2019.1670287

Flaring is a combustion process commonly used in the oil and gas industry to dispose flammable waste gases. Flare flameout occurs when these gases escape unburnt from the flare tip causing the discharge of flammable and/or toxic vapor clouds. The tox... Read More about Dynamic reliability assessment of flare systems by combining fault tree analysis and Bayesian networks.

Safety + AI: A novel approach to update safety models using artificial intelligence (2019)
Journal Article
Gheraibia, Y., Kabir, S., Aslansefat, K., Sorokos, I., & Papadopoulos, Y. (2019). Safety + AI: A novel approach to update safety models using artificial intelligence. IEEE Access, 7, 135855-135869. https://doi.org/10.1109/ACCESS.2019.2941566

Safety-critical systems are becoming larger and more complex to obtain a higher level of functionality. Hence, modeling and evaluation of these systems can be a difficult and error-prone task. Among existing safety models, Fault Tree Analysis (FTA) i... Read More about Safety + AI: A novel approach to update safety models using artificial intelligence.

Variability management in safety-critical systems design and dependability analysis (2019)
Journal Article
de Oliveira, A. L., Braga, R., Masiero, P., Parker, D., Papadopoulos, Y., Habli, I., & Kelly, T. (2019). Variability management in safety-critical systems design and dependability analysis. Journal of software : evolution and process, 31(8), Article e2202. https://doi.org/10.1002/smr.2202

Safety-critical systems are of paramount importance for many application domains, where safety properties are a key driver to engineer critical aspects and avoid system failures. For the benefits of large-scale reuse, software product lines (SPL) hav... Read More about Variability management in safety-critical systems design and dependability analysis.

Model transformation for analyzing dependability of AADL model by using HiP-HOPS (2019)
Journal Article
Mian, Z., Bottaci, L., Papadopoulos, Y., & Mahmud, N. (2019). Model transformation for analyzing dependability of AADL model by using HiP-HOPS. Journal of Systems and Software, 151, 258-282. https://doi.org/10.1016/j.jss.2019.02.019

The Architecture Analysis and Design Language (AADL) has emerged as a potential future standard in aerospace, automobile and avionics industries for model-based development of dependability-critical systems. As AADL is relatively new, some existing a... Read More about Model transformation for analyzing dependability of AADL model by using HiP-HOPS.

Explicit Modelling and Treatment of Repair in Prediction of Dependability (2018)
Journal Article
Aizpurua, J. I., Papadopoulos, Y., & Merle, G. (2018). Explicit Modelling and Treatment of Repair in Prediction of Dependability. IEEE Transactions on Dependable and Secure Computing, 17(6), 1147-1162. https://doi.org/10.1109/TDSC.2018.2857810

In engineering practice, multiple repair actions are considered carefully by designers, and their success or failure defines further control actions and the evolution of the system state. Such treatment is not fully supported by the current state-of-... Read More about Explicit Modelling and Treatment of Repair in Prediction of Dependability.

A review of applications of fuzzy sets to safety and reliability engineering (2018)
Journal Article
Kabir, S., & Papadopoulos, Y. (2018). A review of applications of fuzzy sets to safety and reliability engineering. International Journal of Approximate Reasoning, 100, 29-55. https://doi.org/10.1016/j.ijar.2018.05.005

Safety and reliability are rigorously assessed during the design of dependable systems. Probabilistic risk assessment (PRA) processes are comprehensive, structured and logical methods widely used for this purpose. PRA approaches include, but not limi... Read More about A review of applications of fuzzy sets to safety and reliability engineering.

Timaeus: A digital art studio inspired by antiquity (2018)
Journal Article
Torrao, L., Papadopoulos, Y., & Mckie, D. (2018). Timaeus: A digital art studio inspired by antiquity. Generative art science and technology hard journal,

This project was motivated as an exploration of the capabilities provided by new digital media for creativity, art creation and art therapy. In the ancient Greek world, téchnē, the word for art, used to refer to both art and technology. The expressio... Read More about Timaeus: A digital art studio inspired by antiquity.

Model-based assessment of energy-efficiency, dependability, and cost-effectiveness of waste heat recovery systems onboard ship (2018)
Journal Article
Lampe, J., Rüde, E., Papadopoulos, Y., & Kabir, S. (2018). Model-based assessment of energy-efficiency, dependability, and cost-effectiveness of waste heat recovery systems onboard ship. Ocean engineering, 157, 234-250. https://doi.org/10.1016/j.oceaneng.2018.03.062

Technological systems are not merely designed with a narrow function in mind. Good designs typically aim at reducing operational costs, e.g. through achieving high energy efficiency and improved dependability (i.e. reliability, availability and maint... Read More about Model-based assessment of energy-efficiency, dependability, and cost-effectiveness of waste heat recovery systems onboard ship.

Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks (2018)
Journal Article
Papadopoulos, Y., Walker, M., & Kabir, S. (2018). Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks. Safety science, 105, 55-70. https://doi.org/10.1016/j.ssci.2018.02.001

© 2018 Elsevier Ltd Dynamic systems exhibit time-dependent behaviours and complex functional dependencies amongst their components. Therefore, to capture the full system failure behaviour, it is not enough to simply determine the consequences of diff... Read More about Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks.

Improved dynamic dependability assessment through integration with prognostics (2017)
Journal Article
Aizpurua, J. I., Catterson, V. M., Papadopoulos, Y., Chiacchio, F., & Manno, G. (2017). Improved dynamic dependability assessment through integration with prognostics. IEEE Transactions on Reliability, 66(3), 893-913. https://doi.org/10.1109/tr.2017.2693821

The use of average data for dependability assessments results in a outdated system-level dependability estimation which can lead to incorrect design decisions. With increasing availability of online data, there is room to improve traditional dependab... Read More about Improved dynamic dependability assessment through integration with prognostics.

Supporting group maintenance through prognostics-enhanced dynamic dependability prediction (2017)
Journal Article
Papadopoulos, Y., Aizpurua, J. I., Catterson, V. M., Chiacchio, F., D'Urso, D., Papadopoulos, Y., …D'Urso, D. (2017). Supporting group maintenance through prognostics-enhanced dynamic dependability prediction. Reliability Engineering and System Safety, 168, 171-188. https://doi.org/10.1016/j.ress.2017.04.005

Condition-based maintenance strategies adapt maintenance planning through the integration of online condition monitoring of assets. The accuracy and cost-effectiveness of these strategies can be improved by integrating prognostics predictions and gro... Read More about Supporting group maintenance through prognostics-enhanced dynamic dependability prediction.

On cost-effective reuse of components in the design of complex reconfigurable systems (2017)
Journal Article
Aizpurua, J. I., Papadopoulos, Y., Muxika, E., Chiacchio, F., & Manno, G. (2017). On cost-effective reuse of components in the design of complex reconfigurable systems. Quality and Reliability Engineering International, 33(7), 1387-1406. https://doi.org/10.1002/qre.2112

Design strategies that benefit from the reuse of system components can reduce costs while maintaining or increasing dependability—we use the term dependability to tie together reliability and availability. D3H2 (aDaptive Dependable Design for systems... Read More about On cost-effective reuse of components in the design of complex reconfigurable systems.

Fuzzy temporal fault tree analysis of dynamic systems (2016)
Journal Article
Kabir, S., Papadopoulos, Y., Walker, M., Rüde, E., & Securius, P. (2016). Fuzzy temporal fault tree analysis of dynamic systems. International Journal of Approximate Reasoning, 77, 20-37. https://doi.org/10.1016/j.ijar.2016.05.006

Fault tree analysis (FTA) is a powerful technique that is widely used for evaluating system safety and reliability. It can be used to assess the effects of combinations of failures on system behaviour but is unable to capture sequence dependent dynam... Read More about Fuzzy temporal fault tree analysis of dynamic systems.

A synthesis of logic and bio-inspired techniques in the design of dependable systems (2016)
Journal Article
Papadopoulos, Y., Walker, M., Parker, D., Sharvia, S., Bottaci, L., Kabir, S., …Sorokos, I. (2016). A synthesis of logic and bio-inspired techniques in the design of dependable systems. Annual Reviews in Control, 41, 170-182. https://doi.org/10.1016/j.arcontrol.2016.04.008

Much of the development of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, can be attributed to the application of advances in formal logic and its application to fault forecast... Read More about A synthesis of logic and bio-inspired techniques in the design of dependable systems.

Application of the D3H2 methodology for the cost-effective design of dependable systems (2016)
Journal Article
Aizpurua, J. I., Muxika, E., Papadopoulos, Y., Chiacchio, F., & Manno, G. (2016). Application of the D3H2 methodology for the cost-effective design of dependable systems. Safety, 2(2), Article 9. https://doi.org/10.3390/safety2020009

The use of dedicated components as a means of achieving desirable levels of fault tolerance in a system may result in high costs. A cost effective way of restoring failed functions is to use heterogeneous redundancies: components that, besides perfor... Read More about Application of the D3H2 methodology for the cost-effective design of dependable systems.

Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets (2015)
Journal Article
Kabir, S., Papadopoulos, Y., & Walker, M. (2015). Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets. IFAC Proceedings Volumes/ International Federation of Automatic Control, 48(21), 458-463. https://doi.org/10.1016/j.ifacol.2015.09.569

© 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Using classical combinatorial fault trees, analysts are able to assess the effects of combinations of failures on system behaviour but are unab... Read More about Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets.

A synthesis of logic and biology in the design of dependable systems (2015)
Journal Article
Papadopoulos, Y. (2015). A synthesis of logic and biology in the design of dependable systems. IFAC Proceedings Volumes/ International Federation of Automatic Control, 28(7), 1-8. https://doi.org/10.1016/j.ifacol.2015.06.465

The technologies of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, have advanced in recent years. Much of this development can be attributed to the application of advances in f... Read More about A synthesis of logic and biology in the design of dependable systems.

Model transformation for multi-objective architecture optimisation of dependable systems (2015)
Journal Article
Mian, Z., Bottaci, L., Papadopoulos, Y., Sharvia, S., & Mahmud, N. (2015). Model transformation for multi-objective architecture optimisation of dependable systems. Advances in Intelligent Systems and Computing, 307, 91-110. https://doi.org/10.1007/978-3-319-08964-5_6

The promise of model-based engineering is that by use of an integrated and coherent system model both functional and non-functional requirements may be analysed, implemented and tested in a rigorous and cost-effective manner. An important part of mod... Read More about Model transformation for multi-objective architecture optimisation of dependable systems.

An approach to safety analysis of clinical workflows (2014)
Journal Article
Al-Qora'n, L., Gordon, N., Sharvia, S., Walker, M., & Papadopoulos, Y. (2014). An approach to safety analysis of clinical workflows. Athens Journal of Health, 1(3), 201-216. https://doi.org/10.30958/ajh.1-3-4

A clinical workflow considers the information and processes that are involved in providing a clinical service. They are safety critical since even minor faults have the potential to propagate and consequently cause harm to a patient, or even for a pa... Read More about An approach to safety analysis of clinical workflows.

Enhancing the EAST-ADL error model with HiP-HOPS semantics (2014)
Journal Article
Sharvia, S., Papadopoulos, Y., Chen, D., Walker, M., Yuan, W., & Lönn, H. (2014). Enhancing the EAST-ADL error model with HiP-HOPS semantics. Athens journal of technology & engineering, 1(2), 119-136

EAST-ADL is a domain-specific modelling language for the engineering of automotive embedded systems. The language has abstractions that enable engineers to capture a variety of information about design in the course of the lifecycle — from requiremen... Read More about Enhancing the EAST-ADL error model with HiP-HOPS semantics.

Automatic optimisation of system architectures using EAST-ADL (2013)
Journal Article
Walker, M., Reiser, M., Tucci-Piergiovanni, S., Papadopoulos, Y., Lönn, H., Mraidha, C., …Servat, D. (2013). Automatic optimisation of system architectures using EAST-ADL. Journal of Systems and Software, 86(10), 2467-2487. https://doi.org/10.1016/j.jss.2013.04.001

There are many challenges which face designers of complex system architectures, particularly safety-critical or real-time systems. The introduction of Architecture Description Languages (ADLs) has helped to meet these challenges by consolidating info... Read More about Automatic optimisation of system architectures using EAST-ADL.

Compositional synthesis of temporal fault trees from state machines (2012)
Journal Article
Papadopoulos, Y., Walker, M., & Mahmud, N. (2012). Compositional synthesis of temporal fault trees from state machines. Performance Evaluation Review, 39(4), 79-88. https://doi.org/10.1145/2185395.2185444

Dependability analysis of a dynamic system which is embedded with several complex interrelated components raises two main problems. First, it is difficult to represent in a single coherent and complete picture how the system and its constituent parts... Read More about Compositional synthesis of temporal fault trees from state machines.

Integrated safety and architecture modeling for automotive embedded systems (2011)
Journal Article
Chen, D., Johansson, R., Lönn, H., Blom, H., Walker, M., Papadopoulos, Y., …Sandberg, A. (2011). Integrated safety and architecture modeling for automotive embedded systems. Elektrotechnik und Informationstechnik : E & I, 128(6), 196-202. https://doi.org/10.1007/s00502-011-0007-7

EAST-ADL is an architecture description language (ADL) for model-based development of automotive embedded systems. The formalization of domain-specific engineering information and methodology brings a potential for a wide range of benefits for inform... Read More about Integrated safety and architecture modeling for automotive embedded systems.

An approach to optimization of fault tolerant architectures using HiP-HOPS (2011)
Journal Article
Adachi, M., Papadopoulos, Y., Sharvia, S., Parker, D., & Tohdo, T. (2011). An approach to optimization of fault tolerant architectures using HiP-HOPS. Software: Practice and Experience, 41(11), 1303-1327. https://doi.org/10.1002/spe.1044

New processes for the design of dependable systems must address both cost and dependability concerns. They should also maximize the potential for automation to address the problem of increasing technological complexity and the potentially immense des... Read More about An approach to optimization of fault tolerant architectures using HiP-HOPS.

Capture and reuse of composable failure patterns (2010)
Journal Article
Wolforth, I., Walker, M., Papadopoulos, Y., & Grunske, L. (2010). Capture and reuse of composable failure patterns. International Journal of Critical Computer-Based Systems, 1(1/2/3), 128-147. https://doi.org/10.1504/IJCCBS.2010.031710

Emerging safety analysis techniques use composition of failure models or fault simulation in formal models of a system to determine relationships between the causes and effects of failure. Most recent work has focused on developing system modelling a... Read More about Capture and reuse of composable failure patterns.

Generalizable safety annotations for specification of failure patterns (2010)
Journal Article
Papadopoulos, Y., Walker, M., Grunske, L., & Wolforth, I. (2010). Generalizable safety annotations for specification of failure patterns. Software: Practice and Experience, 40(5), 453-483. https://doi.org/10.1002/spe.966

Components in programmable systems often exhibit patterns of failure that are independent of function or system context. In this paper, we show that it is possible to capture, and reuse where appropriate, such patterns for the purposes of system safe... Read More about Generalizable safety annotations for specification of failure patterns.

Qualitative temporal analysis: Towards a full implementation of the Fault Tree Handbook (2009)
Journal Article
Papadopoulos, Y., & Walker, M. (2009). Qualitative temporal analysis: Towards a full implementation of the Fault Tree Handbook. Control engineering practice, 17(10), 1115-1125. https://doi.org/10.1016/j.conengprac.2008.10.003

The Fault tree handbook has become the de facto standard for fault tree analysis (FTA), defining the notation and mathematical foundation of this widely used safety analysis technique. The Handbook recognises that classical combinatorial fault trees... Read More about Qualitative temporal analysis: Towards a full implementation of the Fault Tree Handbook.

Semi-automatic FMEA supporting complex systems with combinations and sequences of failures (2009)
Journal Article
Walker, M., Papadopoulos, Y., Parker, D., Lönn, H., Törngren, M., Chen, D., …Sandberg, A. (2009). Semi-automatic FMEA supporting complex systems with combinations and sequences of failures. SAE International Journal of Passenger Cars - Mechanical Systems, 2(1), 791-802. https://doi.org/10.4271/2009-01-0738

Failure Modes and Effects Analysis (FMEA) is a well established safety analysis technique used for the assessment of safety critical engineering systems in the automotive industry. Although FMEA has been shown to be useful, the analysis is typically... Read More about Semi-automatic FMEA supporting complex systems with combinations and sequences of failures.

Multi-objective optimization of dependability attributes using an asynchronous heterogeneous hierarchical parallel genetic algorithm (2008)
Journal Article
Wenhua, Z., Papadopoulos, Y., & Parker, D. (2008). Multi-objective optimization of dependability attributes using an asynchronous heterogeneous hierarchical parallel genetic algorithm. IFAC Proceedings Volumes/ International Federation of Automatic Control, 41(3), 199-204. https://doi.org/10.3182/20081205-2-cl-4009.00036

The optimal satisfaction of dependability attributes and cost, in the design of engineering systems, is a hard multi-objective optimization problem which requires automated algorithms that can effectively search large design spaces. In this paper, a... Read More about Multi-objective optimization of dependability attributes using an asynchronous heterogeneous hierarchical parallel genetic algorithm.

Synthesis and analysis of temporal fault trees with PANDORA: the time of Priority AND gates (2007)
Journal Article
Walker, M., & Papadopoulos, Y. (2008). Synthesis and analysis of temporal fault trees with PANDORA: the time of Priority AND gates. Nonlinear Analysis: Hybrid Systems, 2(2), 368-382. https://doi.org/10.1016/j.nahs.2006.05.003

Classical Fault Tree Analysis (FTA) can determine the effects of combinations of failure events on a system but cannot capture the significance of the temporal order of events, which may be critical. In this paper, we propose an extension based on fo... Read More about Synthesis and analysis of temporal fault trees with PANDORA: the time of Priority AND gates.