3,103 research outputs found

    Non-Functional Properties in Service Selection

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    Service selection is an important step of the service composition process. Multiple services functionally equivalent might be offered by different providers but characterized by different non functional properties such as Quality of Service (QoS) values (e.g. execution price, success rate) and transactional properties (e.g. compensatable or not). Since the QoS of the selected services has an impact on the QoS of the produced composite service, the best set of services to be selected is the set that maximize the QoS of the composite service. In the literature, many approaches have been proposed for the QoS-aware service selection problem which has been formalized as an optimization problem. The talk will first overview some optimization techniques and their application to the service selection problem and next present a service selection approach based not only according to their functional requirements but also to their transactional properties.Universidad de Málaga. Campus de Excelencia Internacional Andalucí

    Multi-party Contract Management for Microservices

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    This paper discusses the necessary steps and means for ensuring the successful deployment and execution of software components referred to as microservices on top of platforms referred to as Internet of Things (IoT) devices, clouds, and edges. These steps and means are packaged into formal documents known in the literature as contracts. Because of the multi-dimensional nature of deploying and executing microservices, contracts are specialized into discovery, deployment, and collaboration types, capturing each specific aspect of the completion of these contracts. This completion is associated with a set of Quality-of-Service (QoS) parameters that are monitored allowing to identify potential deviations between what has been agreed upon and what has really happened. To demonstrate the technical doability of contracts, a system is implemented using different datasets that support experiments related to assessing the impact of the number of microservices and platforms on the performance o f the system

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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