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Samy Abbes

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

7 papers

1 author row

I&C Journal 2017 Journal Article

Synchronization of Bernoulli sequences on shared letters

Samy Abbes

The topic of this paper is the distributed and incremental generation of long executions of concurrent systems, uniformly or more generally with weights associated to elementary actions. Synchronizing sequences of letters on alphabets sharing letters are known to produce a trace in the concurrency theoretic sense, i. e. , a labeled partially ordered set. We study the probabilistic aspects by considering the synchronization of Bernoulli sequences of letters, under the light of Bernoulli and uniform measures recently introduced for trace monoids. We introduce two algorithms that produce random traces, using only local random primitives. We thoroughly study some specific examples, the path model and the ring model, both of arbitrary size. For these models, we show how to generate any Bernoulli distributed random traces, which includes the case of uniform generation.

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TCS Journal 2014 Journal Article

Application of branching cells to QoS aware service orchestrations

Albert Benveniste
Claude Jard
Samy Abbes

By allowing service calls to be guarded by contexts, Asymmetric Event Structures (AES for short) and contextual nets are a convenient framework to model composite Web services or service orchestrations. We equip AES with QoS domains as a framework to capture a number of QoS metrics and their combination. We use the resulting model to formalize QoS-based late service binding in composite services. When subject to QoS-based late service binding, composite services may be non-monotonic with respect to QoS, meaning that strictly improving the QoS of a service may strictly decrease the end-to-end QoS of the composite service, an embarrassing feature for QoS-aware management; we study this issue. Branching cells of AES play a central role in this study.

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TCS Journal 2014 Journal Article

Branching cells for asymmetric event structures

Samy Abbes

This paper introduces branching cells as elementary units of independent choices in the model of Asymmetric Event Structures (AES), extending a previous work on branching cells for Prime Event Structures. Branching cells consist of subAES of the surrounding AES. Their maximal configurations are shown to tile any maximal configuration of the surrounding AES in a dynamic way. Branching cells for AES are developed in order to allow the analysis of an optimization procedure in the context of QoS management of web services, presented in a companion paper. Other applications of branching cells include the ability to add a probabilistic layer to AES in a natural fashion where concurrency meets probabilistic independence of choices in distinct and parallel branching cells.

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TCS Journal 2014 Journal Article

Foreword in honor of Glynn Winskel

Albert Benveniste
Claude Jard
Samy Abbes

A foreword to the contributed papers on Branching cells for asymmetric event structures and Application of branching cells to QoS aware service orchestrations.

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TCS Journal 2008 Journal Article

True-concurrency probabilistic models: Markov nets and a law of large numbers

Samy Abbes
Albert Benveniste

We introduce the model of Markov nets, a probabilistic extension of safe Petri nets under the true-concurrency semantics—this means that traces, not firing sequences, are given a probability. This model builds upon our previous work on probabilistic event structures. We use the notion of a branching cell for event structures, and show that the latter provides an adequate conception of local state for nets. We prove a Law of Large Numbers (LLN) for Markov nets, which constitutes the main contribution of the paper. This LLN allows for the characterization, in a quantitative way, of the asymptotic behavior of Markov nets.

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TCS Journal 2006 Journal Article

Projective topology on bifinite domains and applications

Samy Abbes
Klaus Keimel

We revisit extension results from continuous valuations to Radon measures for bifinite domains. In the framework of bifinite domains, the Prokhorov theorem (existence of projective limits of Radon measures) appears as a natural tool, and helps building a bridge between Measure theory and Domain theory. The study we present also fills a gap in the literature concerning the coincidence between projective and Lawson topology for bifinite domains. Motivated by probabilistic considerations, we study the extension of measures in order to define Borel measures on the space of maximal elements of a bifinite domain.

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I&C Journal 2006 Journal Article

True-concurrency probabilistic models

Samy Abbes
Albert Benveniste

This paper is devoted to probabilistic models for concurrent systems under their true-concurrency semantics. Here we address probabilistic event structures. We consider a new class of event structures, called locally finite, that extend confusion-free event structure. In locally finite event structures, maximal configurations can be tiled with branching cells: branching cells are minimal and finite sub-structures capturing the choices performed while scanning a maximal configuration. The probabilistic event structures that we introduce have the property that “concurrent processes are independent in the probabilistic sense. ”

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