All Outputs (22)

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.

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.

A model-based extension to HiP-HOPS for dynamic fault propagation studies (2017)
Journal Article
Kabir, S., Papadopoulos, Y., Walker, M., Parker, D., Aizpurua, J. I., Lampe, J., & Rüde, E. (2017). A model-based extension to HiP-HOPS for dynamic fault propagation studies. Lecture notes in computer science, 10437 LNCS, 163-178. https://doi.org/10.1007/978-3-319-64119-5_11

HiP-HOPS is a model-based approach for assessing the dependability of safety-critical systems. The method combines models, logic, probabilities and nature-inspired algorithms to provide advanced capabilities for design optimisation, requirement alloc... Read More about A model-based extension to HiP-HOPS for dynamic fault propagation studies.

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.

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.

Automating allocation of development assurance levels: An extension to HiP-HOPS (2015)
Journal Article
Sorokos, I., Papadopoulos, Y., Azevedo, L., Parker, D., & Walker, M. (2015). Automating allocation of development assurance levels: An extension to HiP-HOPS. IFAC Proceedings Volumes/ International Federation of Automatic Control, 48(7), 9-14. https://doi.org/10.1016/j.ifacol.2015.06.466

Controlling the allocation of safety requirements across a system's architecture from the early stages of development is an aspiration embodied in numerous major safety standards. Manual approaches of applying this process in practice are ineffective... Read More about Automating allocation of development assurance levels: An extension to HiP-HOPS.

A safety analysis approach to clinical workflows : application and evaluation (2014)
Journal Article
Gordon, N., Kabir, S., Sharvia, S., Walker, M., & Al-Qora’n, L. (in press). A safety analysis approach to clinical workflows : application and evaluation. International Journal of Advanced Computer Science and Applications, 4(3), 82-91. https://doi.org/10.14569/SpecialIssue.2014.040310

Clinical workflows are safety critical workflows as they have the potential to cause harm or death to patients. Their safety needs to be considered as early as possible in the development process. Effective safety analysis methods are required to ens... Read More about A safety analysis approach to clinical workflows : application and evaluation.

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.

Exploring the impact of different cost heuristics in the allocation of safety integrity levels (2014)
Journal Article
Azevedo, L. S., Parker, D., Papadopoulos, Y., Walker, M., Sorokos, I., & Araújo, R. E. (2014). Exploring the impact of different cost heuristics in the allocation of safety integrity levels. Lecture notes in computer science, 8822, 70-81. https://doi.org/10.1007/978-3-319-12214-4_6

Contemporary safety standards prescribe processes in which system safety requirements, captured early and expressed in the form of Safety Integrity Levels (SILs), are iteratively allocated to architectural elements. Different SILs reflect different r... Read More about Exploring the impact of different cost heuristics in the allocation of safety integrity levels.

Quantification of temporal fault trees based on fuzzy set theory (2014)
Journal Article
Kabir, S., Edifor, E., Walker, M., & Gordon, N. (2014). Quantification of temporal fault trees based on fuzzy set theory. Advances in Intelligent Systems and Computing, 286, 255-264. https://doi.org/10.1007/978-3-319-07013-1_24

© Springer International Publishing Switzerland 2014. Fault tree analysis (FTA) has been modified in different ways to make it capable of performing quantitative and qualitative safety analysis with temporal gates, thereby overcoming its limitation i... Read More about Quantification of temporal fault trees based on fuzzy set theory.

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.

Assisted assignment of automotive safety requirements (2013)
Journal Article
Azevedo, L. D. S., Parker, D., Walker, M., Papadopoulos, Y., & Araújo, R. E. (2014). Assisted assignment of automotive safety requirements. IEEE Software, 31(1), 62-68. https://doi.org/10.1109/ms.2013.118

ISO 26262, a functional-safety standard, uses Automotive Safety Integrity Levels (ASILs) to assign safety requirements to automotive-system elements. System designers initially assign ASILs to system-level hazards and then allocate them to elements o... Read More about Assisted assignment of automotive safety requirements.

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.

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.

Engineering failure analysis and design optimisation with HiP-HOPS (2010)
Journal Article
Papadopoulos, Y., Walker, M., Parker, D., Rüde, E., Hamann, R., Uhlig, A., …Lien, R. (2011). Engineering failure analysis and design optimisation with HiP-HOPS. Engineering Failure Analysis, 18(2), 590-608. https://doi.org/10.1016/j.engfailanal.2010.09.025

The scale and complexity of computer-based safety critical systems, like those used in the transport and manufacturing industries, pose significant challenges for failure analysis. Over the last decade, research has focused on automating this task. I... Read More about Engineering failure analysis and design optimisation with HiP-HOPS.

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.