326 research outputs found
How to Play Optimally for Regular Objectives?
This paper studies two-player zero-sum games played on graphs and makes contributions toward the following question: given an objective, how much memory is required to play optimally for that objective? We study regular objectives, where the goal of one of the two players is that eventually the sequence of colors along the play belongs to some regular language of finite words. We obtain different characterizations of the chromatic memory requirements for such objectives for both players, from which we derive complexity-theoretic statements: deciding whether there exist small memory structures sufficient to play optimally is NP-complete for both players. Some of our characterization results apply to a more general class of objectives: topologically closed and topologically open sets
Characterizing Omega-Regularity Through Finite-Memory Determinacy of Games on Infinite Graphs
We consider zero-sum games on infinite graphs, with objectives specified as sets of infinite words over some alphabet of colors. A well-studied class of objectives is the one of ?-regular objectives, due to its relation to many natural problems in theoretical computer science. We focus on the strategy complexity question: given an objective, how much memory does each player require to play as well as possible? A classical result is that finite-memory strategies suffice for both players when the objective is ?-regular. We show a reciprocal of that statement: when both players can play optimally with a chromatic finite-memory structure (i.e., whose updates can only observe colors) in all infinite game graphs, then the objective must be ?-regular. This provides a game-theoretic characterization of ?-regular objectives, and this characterization can help in obtaining memory bounds. Moreover, a by-product of our characterization is a new one-to-two-player lift: to show that chromatic finite-memory structures suffice to play optimally in two-player games on infinite graphs, it suffices to show it in the simpler case of one-player games on infinite graphs. We illustrate our results with the family of discounted-sum objectives, for which ?-regularity depends on the value of some parameters
Embrun – Réseau DCAN
Identifiant de l'opération archéologique : 8392 Date de l'opération : 2007 (SU) Inventeur(s) : Margarit Xavier (SRA) Des travaux de réseau consistant en creusement de tranchées ont été réalisés par la ville d’Embrun dans le secteur de l’ancienne Direction des camps de l’aéronavale (DCAN), entre la rue de Lattre-de-Tassigny, la porte du Traître et le parking Delaroche, sans que la consultation préalable, pourtant obligatoire, du service régional de l’Archéologie n’ait été faite. Cette zone, en..
How to Play Optimally for Regular Objectives?
This paper studies two-player zero-sum games played on graphs and makes
contributions toward the following question: given an objective, how much
memory is required to play optimally for that objective? We study regular
objectives, where the goal of one of the two players is that eventually the
sequence of colors along the play belongs to some regular language of finite
words. We obtain different characterizations of the chromatic memory
requirements for such objectives for both players, from which we derive
complexity-theoretic statements: deciding whether there exist small memory
structures sufficient to play optimally is NP-complete for both players. Some
of our characterization results apply to a more general class of objectives:
topologically closed and topologically open sets.Comment: Full version of ICALP 2023 conference paper. 28 pages, 8 figure
Decisiveness of Stochastic Systems and its Application to Hybrid Models (Full Version)
In [ABM07], Abdulla et al. introduced the concept of decisiveness, an
interesting tool for lifting good properties of finite Markov chains to
denumerable ones. Later, this concept was extended to more general stochastic
transition systems (STSs), allowing the design of various verification
algorithms for large classes of (infinite) STSs. We further improve the
understanding and utility of decisiveness in two ways. First, we provide a
general criterion for proving decisiveness of general STSs. This criterion,
which is very natural but whose proof is rather technical, (strictly)
generalizes all known criteria from the literature. Second, we focus on
stochastic hybrid systems (SHSs), a stochastic extension of hybrid systems. We
establish the decisiveness of a large class of SHSs and, under a few classical
hypotheses from mathematical logic, we show how to decide reachability problems
in this class, even though they are undecidable for general SHSs. This provides
a decidable stochastic extension of o-minimal hybrid systems.
[ABM07] Parosh A. Abdulla, Noomene Ben Henda, and Richard Mayr. 2007.
Decisive Markov Chains. Log. Methods Comput. Sci. 3, 4 (2007).Comment: Full version of GandALF 2020 paper (arXiv:2001.04347v2), updated
version of arXiv:2001.04347v1. 30 pages, 6 figure
Electrical variable transmission for hybrid off-highway vehicles
The push for less emissions has driven transportation
towards electrification. The electrical variable transmission
is a promising emerging component that has proven to be
successful in passenger vehicles and is being considered in
this paper for off-highway vehicles. By electromagnetically
coupling the internal combustion engine with the wheels, allowing
independent rotation, the engine is kept in its optimal
operating range. This paper benchmarks the electrical variable
transmission to one of the most successful hybrid topologies:
the Toyota hybrid system. Flanders Make’s Hybrid Electric
Drivetrain CoDesign framework is being used to ensure optimal
control decisions for both. Results show that the electrical
variable transmission may reduce fuel consumption by 30%
and total cost of ownership by 10%
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