38 citations · 208 across the 29 of their papers we have counts for
32 papers
Cross-entropy optimization with prioritized constraints
Francisco Roldan Sanchez, Pau de las Heras Molins, David Fridovich-Keil +1
When constraints conflict, an optimizer must determine which requirements to preserve and which to relax. On the one hand, a priority ordering specifies which requirements take pre…
Cascaded consensus splitting for multi-branch contingency games
Bastien Lechardoy, Pau de las Heras Molins, Thibault Lahire +4
Contingency games enable agents to anticipate and plan for other agents' hypothetical intents by constructing trajectories with a shared prefix and intent-dependent branches. While…
Controllability in preference-conditioned multi-objective reinforcement learning
Pau de las Heras Molins, Beyazit Yalcinkaya, Lasse Peters +2
Multi-objective reinforcement learning (MORL) allows a user to express preference over outcomes in terms of the relative importance of the objectives, but standard metrics cannot c…
Breaking Exponential Complexity in Games of Ordered Preference: A Tractable Reformulation
Dong Ho Lee, Jingqi Li, Lasse Peters +2
Games of ordered preference (GOOPs) model multi-player equilibrium problems in which each player maintains a distinct hierarchy of strictly prioritized objectives. Existing approac…
Compositional shield synthesis for safe reinforcement learning in partial observability
Steven Carr, Georgios Bakirtzis, Ufuk Topcu
Agents controlled by the output of reinforcement learning (RL) algorithms often transition to unsafe states, particularly in uncertain and partially observable environments. Partia…
Approximate solutions to games of ordered preference
Pau de las Heras Molins, Eric Roy-Almonacid, Dong Ho Lee +3
Autonomous vehicles must balance ranked objectives, such as minimizing travel time, ensuring safety, and coordinating with traffic. Games of ordered preference effectively model th…
Navigating the sociotechnical labyrinth: Dynamic certification for responsible embodied AI
Georgios Bakirtzis, Andrea Aler Tubella, Andreas Theodorou +2
Sociotechnical requirements shape the governance of artificially intelligent (AI) systems. In an era where embodied AI technologies are rapidly reshaping various facets of contempo…
Reduce, Reuse, Recycle: Categories for Compositional Reinforcement Learning
Georgios Bakirtzis, Michail Savvas, Ruihan Zhao +2
In reinforcement learning, conducting task composition by forming cohesive, executable sequences from multiple tasks remains challenging. However, the ability to (de)compose tasks…
Negotiating Control: Neurosymbolic Variable Autonomy
Georgios Bakirtzis, Manolis Chiou, Andreas Theodorou
Variable autonomy equips a system, such as a robot, with mixed initiatives such that it can adjust its independence level based on the task's complexity and the surrounding environ…
On the complexity of sabotage games for network security
Dhananjay Raju, Georgios Bakirtzis, Ufuk Topcu
Securing dynamic networks against adversarial actions is challenging because of the need to anticipate and counter strategic disruptions by adversarial entities within complex netw…
Formal Methods for Autonomous Systems
Tichakorn Wongpiromsarn, Mahsa Ghasemi, Murat Cubuktepe +6
Formal methods refer to rigorous, mathematical approaches to system development and have played a key role in establishing the correctness of safety-critical systems. The main buil…
Sensor Placement for Online Fault Diagnosis
Dhananjay Raju, Georgios Bakirtzis, Ufuk Topcu
Fault diagnosis is the problem of determining a set of faulty system components that explain discrepancies between observed and expected behavior. Due to the intrinsic relation bet…
Functional requirements decomposition in set-based design
Minghui Sun, Zhaoyang Chen, Georgios Bakirtzis +2
Designing systems is typically uncertain and ambiguous at early stages. Set-based design supports alternative exploration and gradual uncertainty reduction during the early lifecyc…
Categorical semantics of compositional reinforcement learning
Georgios Bakirtzis, Michail Savvas, Ufuk Topcu
Compositional knowledge representations in reinforcement learning (RL) facilitate modular, interpretable, and safe task specifications. However, generating compositional models req…
STPA-driven Multilevel Runtime Monitoring for In-time Hazard Detection
Smitha Gautham, Georgios Bakirtzis, Alexander Will +2
Runtime verification or runtime monitoring equips safety-critical cyber-physical systems to augment design assurance measures and ensure operational safety and security. Cyber-phys…
AlgebraicSystems: Compositional Verification for Autonomous System Design
Georgios Bakirtzis, Ufuk Topcu
Autonomous systems require the management of several model views to assure properties such as safety and security among others. A crucial issue in autonomous systems design assuran…
Dynamic Certification for Autonomous Systems
Georgios Bakirtzis, Steven Carr, David Danks +1
Autonomous systems are often deployed in complex sociotechnical environments, such as public roads, where they must behave safely and securely. Unlike many traditionally engineered…
Compositional Cyber-Physical Systems Theory
Georgios Bakirtzis
This dissertation builds a compositional cyber-physical systems theory to develop concrete semantics relating the above diverse views necessary for safety and security assurance. I…
Compositional Thinking in Cyberphysical Systems Theory
Georgios Bakirtzis, Eswaran Subrahmanian, Cody H. Fleming
Engineering safe and secure cyber-physical systems requires system engineers to develop and maintain a number of model views, both dynamic and static, which can be seen as algebras…
Yoneda Hacking: The Algebra of Attacker Actions
Georgios Bakirtzis, Fabrizio Genovese, Cody H. Fleming
Our work focuses on modeling the security of systems from their component-level designs. Towards this goal, we develop a categorical formalism to model attacker actions. Equipping…
Compositional Cyber-Physical Systems Modeling
Georgios Bakirtzis, Christina Vasilakopoulou, Cody H. Fleming
Assuring the correct behavior of cyber-physical systems requires significant modeling effort, particularly during early stages of the engineering and design process when a system i…
Cyberphysical Security Through Resiliency: A Systems-centric Approach
Cody Fleming, Carl Elks, Georgios Bakirtzis +4
Cyber-physical systems (CPS) are often defended in the same manner as information technology (IT) systems -- by using perimeter security. Multiple factors make such defenses insuff…
Categorical Semantics of Cyber-Physical Systems Theory
Georgios Bakirtzis, Cody H. Fleming, Christina Vasilakopoulou
Cyber-physical systems require the construction and management of various models to assure their correct, safe, and secure operation. These various models are necessary because of…
An Ontological Metamodel for Cyber-Physical System Safety, Security, and Resilience Coengineering
Georgios Bakirtzis, Tim Sherburne, Stephen Adams +3
System complexity has become ubiquitous in the design, assessment, and implementation of practical and useful cyber-physical systems. This increased complexity is impacting the man…