2,458 research outputs found
A Compositional Semantics for Stochastic Reo Connectors
In this paper we present a compositional semantics for the channel-based
coordination language Reo which enables the analysis of quality of service
(QoS) properties of service compositions. For this purpose, we annotate Reo
channels with stochastic delay rates and explicitly model data-arrival rates at
the boundary of a connector, to capture its interaction with the services that
comprise its environment. We propose Stochastic Reo automata as an extension of
Reo automata, in order to compositionally derive a QoS-aware semantics for Reo.
We further present a translation of Stochastic Reo automata to Continuous-Time
Markov Chains (CTMCs). This translation enables us to use third-party CTMC
verification tools to do an end-to-end performance analysis of service
compositions.Comment: In Proceedings FOCLASA 2010, arXiv:1007.499
Nonlinear Analysis of an Improved Swing Equation
In this paper, we investigate the properties of an improved swing equation
model for synchronous generators. This model is derived by omitting the main
simplifying assumption of the conventional swing equation, and requires a novel
analysis for the stability and frequency regulation. We consider two scenarios.
First we study the case that a synchronous generator is connected to a constant
load. Second, we inspect the case of the single machine connected to an
infinite bus. Simulations verify the results
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