Data-Driven Fault Tree Modeling for Reliability Assessment of Cyber-Physical Systems

Author(s):  
Sanja Lazarova-Molnar ◽  
Parisa Niloofar ◽  
Gabor Kevin Barta
Author(s):  
Vladimir Hahanov ◽  
Volodymyr Miz ◽  
Eugenia Litvinova ◽  
Alexander Mishchenko ◽  
Dmitry Shcherbin

2017 ◽  
Vol 148 ◽  
pp. 257-279 ◽  
Author(s):  
Mischa Schmidt ◽  
M. Victoria Moreno ◽  
Anett Schülke ◽  
Karel Macek ◽  
Karel Mařík ◽  
...  

Author(s):  
Qinxue Li ◽  
Bugong Xu ◽  
Shanbin Li ◽  
Yonggui Liu ◽  
Xuhuan Xie

Owing to the deep integration of the information and communication technologies, power cyber-physical systems (CPSs) have become smart but are vulnerable to cyber attacks. To correctly assess the vulnerability of power CPSs and further study feasible countermeasures, we verify that a data-driven target attack on a nonlinear Granger causality graph (NGCG) can be constructed successfully, even if adversaries cannot acquire the configuration information of the systems. A NGCG is a unified framework for the processing and analysis of nonlinear measurement data or datasets and can be used to evaluate the significance of power nodes or lines. In addition, an algorithm including data-driven parameter estimation, noise removal and data reconstruction based on symplectic geometry is introduced to make the NGCG a parameter-free and noise-tolerant method. In particular, three new indexes on the weight analysis of the NGCG are defined to quantitatively evaluate the significance of power nodes or lines. Finally, several case studies of a nonlinear simulation model and power systems in detail verify the effectiveness and superiority of the proposed data-driven target attack. The results show the proposed target attack can select the key attack targets more accurately and lead to physical system collapse with the least number of attack steps.


Safety ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 26 ◽  
Author(s):  
Victor Bolbot ◽  
Gerasimos Theotokatos ◽  
Evangelos Boulougouris ◽  
George Psarros ◽  
Rainer Hamann

Cyber-Physical Systems (CPSs) represent a systems category developed and promoted in the maritime industry to automate functions and system operations. In this study, a novel Combinatorial Approach for Safety Analysis is presented, which addresses the traditional safety methods’ limitations by integrating System Theoretic Process Analysis (STPA), Events Sequence Identification (ETI) and Fault Tree Analysis (FTA). The developed method results in the development of a detailed Fault Tree that captures the effects of both the physical components/subsystems and the software functions’ failures. The quantitative step of the method employs the components’ failure rates to calculate the top event failure rate along with importance metrics for identifying the most critical components/functions. This method is implemented for an exhaust gas open loop scrubber system safety analysis to estimate its failure rate and identify critical failures considering the baseline system configuration as well as various alternatives with advanced functions for monitoring and diagnostics. The results demonstrate that configurations with SOx sensor continuous monitoring or scrubber unit failure diagnosis/prognosis lead to significantly lower failure rate. Based on the analysis results, the advantages/disadvantages of the novel method are also discussed. This study also provides insights for better safety analysis of the CPSs.


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