43 research outputs found
Compositional nonblocking verification with always enabled events and selfloop-only events
This paper proposes to improve compositional nonblocking verification through the use of always enabled and selfloop-only events. Compositional verification involves abstraction to simplify parts of a system during verification. Normally, this abstraction is based on the set of events not used in the remainder of the system, i.e., in the part of the system not being simplified. Here, it is proposed to exploit more knowledge about the system and abstract events even though they are used in the remainder of the system. Abstraction rules from previous work are generalised, and experimental results demonstrate the applicability of the resulting algorithm to verify several industrial-scale discrete event system models, while achieving better state-space reduction than before
Beam Energy Dependence of Jet-Quenching Effects in Au plus Au Collisions at root s(NN)=7.7, 11.5, 14.5, 19.6, 27, 39, and 62.4 GeV
We report measurements of the nuclear modification factor, , for charged hadrons as well as identified , , and for Au+Au collision energies of = 7.7, 11.5, 14.5, 19.6, 27, 39, and 62.4 GeV. We observe a clear high- net suppression in central collisions at 62.4 GeV for charged hadrons which evolves smoothly to a large net enhancement at lower energies. This trend is driven by the evolution of the pion spectra, but is also very similar for the kaon spectra. While the magnitude of the proton at high does depend on collision energy, neither the proton nor the anti-proton at high exhibit net suppression at any energy. A study of how the binary collision scaled high- yield evolves with centrality reveals a non-monotonic shape that is consistent with the idea that jet-quenching is increasing faster than the combined phenomena that lead to enhancement.We report measurements of the nuclear modification factor RCP for charged hadrons as well as identified π+(-), K+(-), and p(p¯) for Au+Au collision energies of sNN=7.7, 11.5, 14.5, 19.6, 27, 39, and 62.4 GeV. We observe a clear high-pT net suppression in central collisions at 62.4 GeV for charged hadrons which evolves smoothly to a large net enhancement at lower energies. This trend is driven by the evolution of the pion spectra but is also very similar for the kaon spectra. While the magnitude of the proton RCP at high pT does depend on the collision energy, neither the proton nor the antiproton RCP at high pT exhibit net suppression at any energy. A study of how the binary collision-scaled high-pT yield evolves with centrality reveals a nonmonotonic shape that is consistent with the idea that jet quenching is increasing faster than the combined phenomena that lead to enhancement
Fault Diagnosis in Finite-State Automata and Timed Discrete-Event Systems
In this paper, we propose a framework for fault diagnosis in discreteevent systems. In this approach, the system and the diagnoser (the fault detection system) do not have to be initialized at the same time. Furthermore, no information about the state or even the condition (failure status) of the system before the initiation of diagnosis is required. First, a state-based approach for on-line passive fault diagnosis in finitestate automata is presented. The design of the fault detection system, in the worst case, has exponential time complexity. A model reduction scheme with polynomial time complexity is introduced to reduce the computational complexity of the design. Next we consider the use of timing information to improve the accuracy of diagnosis. Instead of directly extending our framework to timed discrete-event systems, we take an alternative apporach which leads to significant reduction in on-line computing power requirements and, in many cases, in the size of the diagnoser at t..