Search Our Scientific Publications & Authors

Acta Inform 2021 20;58(5):497-528. Epub 2020 Feb 20.

State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing, China.

The possible interactions between a controller and its environment can naturally be modelled as the arena of a two-player game, and adding an appropriate winning condition permits to specify desirable behavior. The classical model here is the positional game, where both players can (fully or partially) observe the current position in the game graph, which in turn is indicative of their mutual current states. In practice, neither sensing and actuating the environment through physical devices nor data forwarding to and from the controller and signal processing in the controller are instantaneous. Read More

Acta Inform 2020 6;57(1):223-244. Epub 2019 Dec 6.

1University of California, Berkeley, USA.

We present a sound and automated approach to synthesizing safe, digital controllers for physical plants represented as time-invariant models. Models are linear differential equations with inputs, evolving over a continuous state space. The synthesis precisely accounts for the effects of finite-precision arithmetic introduced by the controller. Read More

Acta Inform 2020 7;57(1):137-163. Epub 2019 Dec 7.

Reactive Systems Group, Saarland University, Saarbrücken, Germany.

We study the reactive synthesis problem for hyperproperties given as formulas of the temporal logic HyperLTL. Hyperproperties generalize trace properties, i.e. Read More

Acta Inform 2020 5;57(1):37-79. Epub 2019 Dec 5.

2University of Leicester, Leicester, UK.

Reactive synthesis for the GR(1) fragment of LTL has been implemented and studied in many works. In this work we present and evaluate a list of heuristics to potentially reduce running times for GR(1) synthesis and related algorithms. The list includes several heuristics for controlled predecessor computation and BDDs, early detection of fixed-points and unrealizability, fixed-point recycling, and several heuristics for unrealizable core computations. Read More

Acta Inform 2019 22;56(7):585-617. Epub 2019 Feb 22.

Radboud University, Toernooiveld 212, Nijmegen, The Netherlands.

Turi and Plotkin introduced an elegant approach to structural operational semantics based on universal coalgebra, parametric in the type of syntax and the type of behaviour. Their framework includes abstract GSOS, a categorical generalisation of the classical GSOS rule format, as well as its categorical dual, coGSOS. Both formats are well behaved, in the sense that each specification has a unique model on which behavioural equivalence is a congruence. Read More

Acta Inform 2017 25;54(4):343-378. Epub 2016 Jan 25.

Reykjavík University, Reykjavík, Iceland.

We present an extension of the actor model with real-time, including deadlines associated with messages, and explicit application-level scheduling policies, e.g.,"earliest deadline first" which can be associated with individual actors. Read More

Acta Inform 2017 24;54(3):271-341. Epub 2016 Dec 24.

3Imperial College London, London, UK.

For higher-order (process) languages, characterising contextual equivalence is a long-standing issue. In the setting of a higher-order -calculus with , we develop , a typed bisimilarity which fully characterises contextual equivalence. To our knowledge, ours is the first characterisation of its kind. Read More