25,704 research outputs found
Dependability checking with StoCharts: Is train radio reliable enough for trains?
Performance, dependability and quality of service (QoS) are prime aspects of the UML modelling domain. To capture these aspects effectively in the design phase, we have recently proposed STOCHARTS, a conservative extension of UML statechart diagrams. In this paper, we apply the STOCHART formalism to a safety critical design problem. We model a part of the European Train Control System specification, focusing on the risks of wireless communication failures in future high-speed cross-European trains. Stochastic model checking with the model checker PROVER enables us to derive constraints under which the central quality requirements are satisfied by the STOCHART model. The paper illustrates the flexibility and maturity of STOCHARTS to model real problems in safety critical system design
A comparative reliability analysis of ETCS train radio communications
StoCharts have been proposed as a UML statechart extension for performance and dependability evaluation, and were applied in the context of train radio reliability assessment to show the principal tractability of realistic cases with this approach. In this paper, we extend on this bare feasibility result in two important directions. First, we sketch the cornerstones of a mechanizable translation of StoCharts to MoDeST. The latter is a process algebra-based formalism supported by the Motor/Mƶbius tool tandem. Second, we exploit this translation for a detailed analysis of the train radio case study
Hadron masses from dynamical, non-perturbatively O(a) improved Wilson fermions
We present results on light hadron masses from simulations of full QCD and
report on experiences in running such simulations on a Hitachi SR8000-F1
supercomputer.Comment: Lattice 2000 (Spectrum), 4 pages, 6 eps figure
Effects of liquid and vapor cesium on structural materials
Literature survey on corrosive effects of liquid and vapor cesium on structural materials, and compatibility of cesium as working fluid for Rankine cycle space power plan
From StoCharts to MoDeST: a comparative reliability analysis of train radio communications
StoCharts have been proposed as a UML statechart extension for performance and dependability evaluation, and have been applied in the context of train radio reliability assessment to show the principal tractability of realistic cases with this approach. In this paper, we extend on this bare feasibility result in two important directions. First, we sketch the cornerstones of a mechanizable translation of StoCharts to MoDeST. The latter is a process algebra-based formalism supported by the Motor/Mƶbius tool tandem. Second, we exploit this translation for a detailed analysis of the train radio case study
Finite volume corrections to the binding energy of the X(3872)
The quark mass dependence of hadrons is an important input for lattice
calculations. We investigate the light quark mass dependence of the binding
energy of the X(3872) in a finite box to next-to-leading order in an effective
field theory for the X(3872) with perturbative pions (XEFT). At this order, the
quark mass dependence is determined by a quark mass-dependent contact
interaction in addition to the one-pion exchange. While there is only a
moderate sensitivity to the light quark masses in the region up to twice their
physical value, the finite volume effects are significant already at box length
as large as 20 fm.Comment: 23 pages, 9 figures, REVTe
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