10,474 research outputs found

    Platform as a service gateway for the Fog of Things

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    Internet of Things (IoT), one of the key research topics in recent years, together with concepts from Fog Computing, brings rapid advancements in Smart City, Monitoring Systems, industrial control, transportation and other fields. These applications require a reconfigurable sensor architecture that can span multiple scenarios, devices and use cases that allow storage, networking and computational resources to be efficiently used on the edge of the network. There are a number of platforms and gateway architectures that have been proposed to manage these components and enable application deployment. These approaches lack horizontal integration between multiple providers as well as higher order functionalities like load balancing and clustering. This is partly due to the strongly coupled nature of the deployed applications, a lack of abstraction of device communication layers as well as a lock-in for communication protocols. This is a major obstacle for the development of a protocol agnostic application environment that allows for single application to be migrated and to work with multiple peripheral devices with varying protocols from different local gateways. This research looks at existing platforms and their shortcomings as well as proposes a messaging based modular gateway platform that enables clustering of gateways and the abstraction of peripheral communication protocols. This allows applications to send and receive messages regardless of their location and destination device protocol, creating a more uniform development environment. Furthermore, it results in a more streamlined application development and testing while providing more efficient use of the gateways resources. Our evaluation of a prototype for the system shows the need for the migration of resources and the QoS advantages of such a system. The presented use-case scenarios show that clustering can prove to be an advantage in certain use-cases as well as the deployment of a larger testing and control environment through the platform

    Chiral Quark Model with Configuration Mixing

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    The implications of one gluon exchange generated configuration mixing in the Chiral Quark Model (χ\chiQMgcm_{gcm}) with SU(3) and axial U(1) symmetry breakings are discussed in the context of proton flavor and spin structure as well as the hyperon β\beta-decay parameters. We find that χ\chiQMgcm_{gcm} with SU(3) symmetry breaking is able to give a satisfactory unified fit for spin and quark distribution functions, with the symmetry breaking parameters α=.4\alpha=.4, β=.7\beta=.7 and the mixing angle ϕ=20o\phi=20^o, both for NMC and the most recent E866 data. In particular, the agreement with data, in the case of GA/GV,Δ8G_A/G_V, \Delta_8, F, D, fsf_s and f3/f8f_3/f_8, is quite striking.Comment: 16 pages, LaTex, Table and Appendix adde

    Some properties of the newly observed X(1835) state at BES

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    Recently the BES collaboration has announced observation of a resonant state in the π+π−η′\pi^+\pi^- \eta' spectrum in J/ψ→γπ+π−η′J/\psi \to \gamma \pi^+\pi^-\eta' decay. Fitting the data with a 0−+0^{-+} state, the mass is determined to be 1833.7 MeV with 7.7σ7.7\sigma statistic significance. This state is consistent with the one extracted from previously reported ppˉp \bar p threshold enhancement data in J/ψ→γppˉJ/\psi \to \gamma p \bar p. We study the properties of this state using QCD anomaly and QCD sum rules assuming X(1835) to be a pseudoscalar and show that it is consistent with data. We find that this state has a sizeable matrix element leading to branching ratios of (2.61∼7.37)×10−3(2.61\sim 7.37)\times 10^{-3} and (2.21∼10.61)×10−2(2.21\sim 10.61)\times 10^{-2} for J/ψ→γGpJ/\psi \to \gamma G_p and for Gp→π+π−η′G_p \to \pi^+\pi^- \eta', respectively. Combining the calculated branching ratio of J/ψ→γGpJ/\psi \to \gamma G_p and data on threshold enhancement in J/ψ→γppˉJ/\psi \to \gamma p \bar p, we determine the coupling for Gp−p−pˉG_p- p-\bar p interaction. We finally study branching ratios of other J/ψ→γ+threemesonsJ/\psi \to \gamma + {three mesons} decay modes. We find that J/ψ→γGp→γ(π+π−η,KKπ0)J/\psi \to \gamma G_p \to \gamma (\pi^+\pi^- \eta, K K \pi^0) can provide useful tests for the mechanism proposed.Comment: 13 pages, 3 figures. The final version to appear at EPJ

    Observational Constraints on Teleparallel Dark Energy

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    We use data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), and Cosmic Microwave Background (CMB) observations to constrain the recently proposed teleparallel dark energy scenario based on the teleparallel equivalent of General Relativity, in which one adds a canonical scalar field, allowing also for a nonminimal coupling with gravity. Using the power-law, the exponential and the inverse hyperbolic cosine potential ansatzes, we show that the scenario is compatible with observations. In particular, the data favor a nonminimal coupling, and although the scalar field is canonical the model can describe both the quintessence and phantom regimes.Comment: 19 pages, 6 figures, version accepted by JCA

    Operator entanglement of two-qubit joint unitary operations revisited: Schmidt number approach

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    Operator entanglement of two-qubit joint unitary operations is revisited. Schmidt number is an important attribute of a two-qubit unitary operation, and may have connection with the entanglement measure of the unitary operator. We found the entanglement measure of two-qubit unitary operators is classified by the Schmidt number of the unitary operators. The exact relation between the operator entanglement and the parameters of the unitary operator is clarified too.Comment: To appear in the Brazilian Journal of Physic

    SU(4) Chiral Quark Model with Configuration Mixing

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    Chiral quark model with configuration mixing and broken SU(3)\times U(1) symmetry has been extended to include the contribution from c\bar c fluctuations by considering broken SU(4) instead of SU(3). The implications of such a model have been studied for quark flavor and spin distribution functions corresponding to E866 and the NMC data. The predicted parameters regarding the charm spin distribution functions, for example, \Delta c, \frac{\Delta c}{{\Delta \Sigma}}, \frac{\Delta c}{c} as well as the charm quark distribution functions, for example, \bar c, \frac{2\bar c}{(\bar u+\bar d)}, \frac{2 \bar c}{(u+d)} and \frac{(c+ \bar c)}{\sum (q+\bar q)} are in agreement with other similar calculations. Specifically, we find \Delta c=-0.009, \frac{\Delta c}{{\Delta \Sigma}}=-0.02, \bar c=0.03 and \frac{(c+ \bar c)}{\sum (q+\bar q)}=0.02 for the \chiQM parameters a=0.1, \alpha=0.4, \beta=0.7, \zeta_{E866}=-1-2 \beta, \zeta_{NMC}=-2-2 \beta and \gamma=0.3, the latter appears due to the extension of SU(3) to SU(4).Comment: 10 RevTeX pages. Accepted for publication in Phys. Rev.
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