Visible to the public Biblio

Filters: Author is Karsai, G.  [Clear All Filters]
2019-01-21
Hasan, S., Ghafouri, A., Dubey, A., Karsai, G., Koutsoukos, X..  2018.  Vulnerability analysis of power systems based on cyber-attack and defense models. 2018 IEEE Power Energy Society Innovative Smart Grid Technologies Conference (ISGT). :1–5.

Reliable operation of power systems is a primary challenge for the system operators. With the advancement in technology and grid automation, power systems are becoming more vulnerable to cyber-attacks. The main goal of adversaries is to take advantage of these vulnerabilities and destabilize the system. This paper describes a game-theoretic approach to attacker / defender modeling in power systems. In our models, the attacker can strategically identify the subset of substations that maximize damage when compromised. However, the defender can identify the critical subset of substations to protect in order to minimize the damage when an attacker launches a cyber-attack. The algorithms for these models are applied to the standard IEEE-14, 39, and 57 bus examples to identify the critical set of substations given an attacker and a defender budget.

2018-05-09
Hasan, S., Ghafouri, A., Dubey, A., Karsai, G., Koutsoukos, X..  2017.  Heuristics-based approach for identifying critical N \#x2014; k contingencies in power systems. 2017 Resilience Week (RWS). :191–197.

Reliable operation of electrical power systems in the presence of multiple critical N - k contingencies is an important challenge for the system operators. Identifying all the possible N - k critical contingencies to design effective mitigation strategies is computationally infeasible due to the combinatorial explosion of the search space. This paper describes two heuristic algorithms based on the iterative pruning of the candidate contingency set to effectively and efficiently identify all the critical N - k contingencies resulting in system failure. These algorithms are applied to the standard IEEE-14 bus system, IEEE-39 bus system, and IEEE-57 bus system to identify multiple critical N - k contingencies. The algorithms are able to capture all the possible critical N - k contingencies (where 1 ≤ k ≤ 9) without missing any dangerous contingency.

2015-11-12
Emfinger, W., Karsai, G..  2015.  Modeling Network Medium Access Protocols for Network Quality of Service Analysis. Real-Time Distributed Computing (ISORC), 2015 IEEE 18th International Symposium on. :292-295.

Design-time analysis and verification of distributed real-time embedded systems necessitates the modeling of the time-varying performance of the network and comparing that to application requirements. Earlier work has shown how to build a system network model that abstracted away the network's physical medium and protocols which govern its access and multiplexing. In this work we show how to apply a network medium channel access protocol, such as Time-Division Multiple Access (TDMA), to our network analysis methods and use the results to show that the abstracted model without the explicit model of the protocol is valid.