no code implementations • 16 Apr 2024 • Rui Yan, Gabriel Santos, Gethin Norman, David Parker, Marta Kwiatkowska
For the partially-informed agent, we propose a continual resolving approach which uses lower bounds, pre-computed offline with heuristic search value iteration (HSVI), instead of opponent counterfactual values.
no code implementations • 14 Mar 2024 • Tomáš Brázdil, Krishnendu Chatterjee, Martin Chmelik, Vojtěch Forejt, Jan Křetínský, Marta Kwiatkowska, Tobias Meggendorfer, David Parker, Mateusz Ujma
The presented framework focuses on probabilistic reachability, which is a core problem in verification, and is instantiated in two distinct scenarios.
no code implementations • 17 Oct 2023 • Rui Yan, Gabriel Santos, Gethin Norman, David Parker, Marta Kwiatkowska
Stochastic games are a well established model for multi-agent sequential decision making under uncertainty.
no code implementations • 19 Sep 2023 • Shili Sheng, David Parker, Lu Feng
POMDP online planning algorithms such as Partially Observable Monte-Carlo Planning (POMCP) can solve very large POMDPs with the goal of maximizing the expected return.
1 code implementation • 12 Sep 2023 • Daniel Fentham, David Parker, Mark Ryan
When deploying classifiers in the real world, users expect them to respond to inputs appropriately.
no code implementations • 5 Aug 2023 • David Parker
Probabilistic model checking is a technique for formal automated reasoning about software or hardware systems that operate in the context of uncertainty or stochasticity.
no code implementations • 30 Jun 2023 • Rui Yan, Gabriel Santos, Gethin Norman, David Parker, Marta Kwiatkowska
This requires functions over continuous-state beliefs, for which we propose a novel piecewise linear and convex representation (P-PWLC) in terms of polyhedra covering the continuous-state space and value vectors, and extend Bellman backups to this representation.
1 code implementation • 4 Jan 2023 • Thom Badings, Licio Romao, Alessandro Abate, David Parker, Hasan A. Poonawala, Marielle Stoelinga, Nils Jansen
This iMDP is, with a user-specified confidence probability, robust against uncertainty in the transition probabilities, and the tightness of the probability intervals can be controlled through the number of samples.
1 code implementation • 31 May 2022 • Marnix Suilen, Thiago D. Simão, David Parker, Nils Jansen
Markov decision processes (MDPs) are formal models commonly used in sequential decision-making.
no code implementations • 13 Feb 2022 • Rui Yan, Gabriel Santos, Gethin Norman, David Parker, Marta Kwiatkowska
Second, we introduce two novel representations for the value functions and strategies, constant-piecewise-linear (CON-PWL) and constant-piecewise-constant (CON-PWC) respectively, and propose Minimax-action-free PI by extending a recent PI method based on alternating player choices for finite state spaces to Borel state spaces, which does not require normal-form games to be solved.
1 code implementation • 10 Jan 2022 • Edoardo Bacci, David Parker
Deep reinforcement learning is an increasingly popular technique for synthesising policies to control an agent's interaction with its environment.
no code implementations • 25 Oct 2021 • Thom S. Badings, Alessandro Abate, Nils Jansen, David Parker, Hasan A. Poonawala, Marielle Stoelinga
We use state-of-the-art verification techniques to provide guarantees on the iMDP, and compute a controller for which these guarantees carry over to the autonomous system.
no code implementations • 10 May 2021 • Shenghui Chen, Kayla Boggess, David Parker, Lu Feng
Complex real-world applications of cyber-physical systems give rise to the need for multi-objective controller synthesis, which concerns the problem of computing an optimal controller subject to multiple (possibly conflicting) criteria.
no code implementations • 4 Mar 2021 • Feng Ye, Zachary Morgan, Wei Tian, Songxue Chi, XiaoPing Wang, Michael E. Manley, David Parker, Mojammel A. Khan, J. F. Mitchell, Randy Fishman
Despite the $J_{{\rm eff}}=1/2$ moments, the spin Hamiltonian is denominated by a large in-plane anisotropy $K_z \sim -1$ meV.
Strongly Correlated Electrons Materials Science
no code implementations • 14 May 2020 • Edoardo Bacci, David Parker
Deep reinforcement learning has been successfully applied to many control tasks, but the application of such agents in safety-critical scenarios has been limited due to safety concerns.
no code implementations • 7 Mar 2018 • Fatma Faruq, Bruno Lacerda, Nick Hawes, David Parker
We propose novel techniques for task allocation and planning in multi-robot systems operating in uncertain environments.
no code implementations • 21 Jun 2015 • Gethin Norman, David Parker, Xueyi Zou
We then propose techniques to either verify that such a property holds or to synthesise a controller for the model which makes it true.
Logic in Computer Science Systems and Control