Lei Song

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In this paper we present a probabilistic broadcast calculus for mobile and wireless networks whose connections are unreliable. In our calculus, broad-casted messages can be lost with a certain probability, and due to mobility the connection probabilities may change. If a network broadcasts a message from a location, it will evolve to a network distribution(More)
Probabilistic automata (PA) [20] have been successfully applied in the formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on PCTL [11] and its extension PCTL * [4]. Various behav-ioral equivalences are proposed for PAs, as a(More)
In optical wavelength-division multiplexing (WDM) networks, the progress in new technologies is paving the road towards dynamic optical transport networks in which leasable circuits can be set up and released on a short-term basis while providing huge capacities to bandwidth-hungry applications. Since interruption of a high-speed optical connection means a(More)
Telecommunications service providers (SP) should place survivability expectations by guaranteeing maximal allowed system downtime for service-level agreement (SLA)-differentiated services. Furthermore, SPs should continuously focus on utilizing network resources effectively, by considering the bounded network capacity and the growth of future data traffic.(More)
This paper presents a formal characterisation of safety and liveness properties for fully probabilistic systems. As for the classical setting, it is established that any (probabilistic tree) property is equivalent to a conjunction of a safety and liveness property. A simple algorithm is provided to obtain such a property decomposition for flat probabilistic(More)
The following full text is a preprint version which may differ from the publisher's version. Abstract. The spectrum of branching-time relations for probabilistic systems has been investigated thoroughly by Baier, Hermanns, Katoen and Wolf (2003, 2005), including weak simulation for systems involving substochastic distributions. Weak simulation was proven to(More)
We introduce a continuous time stochastic broadcast calculus for mobile and wireless networks. The mobility between nodes in a network is mod-eled by a stochastic mobility function which allows to change part of a network topology depending on an exponentially distributed delay and a network topology constraint. We allow continuous time stochastic behavior(More)
We previously demonstrated that a significant proportion of interphotoreceptor retinoid-binding protein (IRBP)-specific uveitogenic T cells in the C57BL/6 mouse and Lewis rat express CD8. The aims of this study were to determine whether some of the IRBP-specific T cells in the B10RIII mouse also express CD8 and whether CD8 and CD4 IRBP-specific T cells in(More)