314 research outputs found

    DynaMod: Dynamische Analyse fĂŒr modellgetriebene Software-Modernisierung

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    Erfolgreiche Softwaresysteme leben lange. Gleichzeitig sind diese jedoch der enormen Geschwindigkeit der Fortentwicklung der technischen Komponenten und Plattformen unterworfen, so dass die Anwendungen technisch sehr schnell altern. Von dieser Alterung sind jedoch nicht nur Programmiertechniken betroffen, sondern auch die Softwarearchitekturen erodieren sehr schnell. Um dieser Alterung entgegenzuwirken, neue technologische Potentiale zu nutzen und auch auf zukĂŒnftige Anforderungen flexibel reagieren zu können, ist eine kontinuierliche Modernisierung von Softwaresystemen erforderlich. Bei der Neuentwicklung von Softwaresystemen hat sich mit der Modellgetriebenen Softwareentwicklung (Model-Driven Software Development, MDSD) ein Konzept etabliert, das eine elegante Lösung dieser Problematik bietet: Anstatt das System vollstĂ€ndig in einer technischen Programmiersprache zu entwickeln, werden fachliche Aspekte mittels geeigneter, abstrakter Modellierungssprachen dargestellt. Hierbei handelt es sich oftmals um sogenannte domĂ€nenspezifische Sprachen (Domain Specific Languages, DSLs), die speziell auf die betreffende AnwendungsdomĂ€ne zugeschnitten sind und dadurch eine knappe und prĂ€zise Formulierung der relevanten Sachverhalte ermöglichen. Die ÜberfĂŒhrung dieser abstrakten Modelle in technische Artefakte, beispielsweise Quellcode in einer Programmiersprache, wird automatisiert durch Codegeneratoren vorgenommen. Auf diese Weise ist es möglich, durch Anpassung der Generatoren die Implementierung der Modelle zu verĂ€ndern, ohne Modifikationen an den zugrundeliegenden Modellen vornehmen zu mĂŒssen. Im Gegensatz zu Neuentwicklungen stehen bei vielen Bestandssystemen keine derartigen Modelle zur VerfĂŒgung. Klassische AnsĂ€tze der Modernisierung von Bestandssystemen versuchen stattdessen, die im Quellcode unmittelbar codierten Strukturen des bestehenden Systems automatisiert in Quellcode des Neusystems zu ĂŒberfĂŒhren. Da durch diesen Ansatz eine Transformation auf sehr elementarer Ebene stattfindet, kann dieser Ansatz der zuvor erwĂ€hnten Erosion der Anwendungsarchitektur nicht begegnen. Zudem ist auch die Übertragung elementarer Strukturen zwischen Programmiersprachen nicht trivial; hĂ€ufig muss in der Zielsprache das originĂ€re Konstrukt mit zusĂ€tzlichem Aufwand simuliert werden. Dadurch kommt es zu einer AufblĂ€hung des Quellcodes, was der Wartbarkeit abtrĂ€glich ist. Zuletzt bleiben technologische Potentiale der Zielplattform hĂ€ufig ungenutzt, da das ursprĂŒngliche System letztlich strukturuell unverĂ€ndert ĂŒbertragen wird. Im DynaMod-Projekt wurde mit der modellgetriebenen Modernisierung (Model Driven Modernisation, MDM) ein neuer, innovativer Ansatz untersucht, Modelle aus bestehenden Softwaresystemen abzuleiten, die in einem MDSD-Prozess genutzt werden können und dem Bestandssystem auf diese Weise die zuvor beschriebene FlexibilitĂ€t der Implementierung verleiht. Zur Ableitung dieser Modelle werden nicht nur die statischen Strukturen des Softwaresystems betrachtet; ein besonderer Schwerpunkt ist die Nutzung dynamischer Analyseverfahren, d.h. der Untersuchung des Verhaltens des Softwaresystems zur Laufzeit. Diese dynamischen Analysen erlauben Einblick in die tatsĂ€chliche Nutzung des Systems durch die Nutzer und produziert somit Informationen, die zur Modernisierung eines Systems unabdingbar sind. Von besonderem Interesse ist eine gleichzeitige Betrachtung statisch und dynamisch gewonnener Informationen, eine sogenannte hybride Analyse. Hierbei entfaltet die Nutzung abstrakter Modelle eine besondere StĂ€rke, da die Modelle eine Plattform bieten, auf der die verschiedenen Daten zusammengefĂŒhrt werden können. Auch Daten aus anderen Quellen, beispielsweise Expertenwissen, können den Modellen hinzugefĂŒgt werden und fĂŒhren Wissen auf der Semantikebene hinzu, das automatisiert nicht erhoben werden kann. Auf diese Weise zeigen die Modelle ein strukturiertes und umfangreiches Bild der Anwendung, das als Grundlage fĂŒr eine Modernisierung dienen kann. Neben der eigentlichen Modernisierung lag ein weiterer Fokus auf der Nutzung der gewonnenen Analysedaten zum systematischen Testen der modernisierten Anwendung. Hier bestand das Ziel darin, Methoden zu entwickeln und zu erproben, die Tests zur PrĂŒfung funktionaler und nicht-funktionaler Eigenschaften der Anwendung aus den Analysedaten generieren können

    Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

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    The production of tt‟ , W+bb‟ and W+cc‟ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓΜ , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of tt‟t\overline{t}, W+bb‟W+b\overline{b} and W+cc‟W+c\overline{c} is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ±\pm 0.02 \mbox{fb}^{-1}. The WW bosons are reconstructed in the decays W→ℓΜW\rightarrow\ell\nu, where ℓ\ell denotes muon or electron, while the bb and cc quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

    Measurement of the J/ψ pair production cross-section in pp collisions at s=13 \sqrt{s}=13 TeV

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    The production cross-section of J/ψ pairs is measured using a data sample of pp collisions collected by the LHCb experiment at a centre-of-mass energy of s=13 \sqrt{s}=13 TeV, corresponding to an integrated luminosity of 279 ±11 pb−1^{−1}. The measurement is performed for J/ψ mesons with a transverse momentum of less than 10 GeV/c in the rapidity range 2.0 < y < 4.5. The production cross-section is measured to be 15.2 ± 1.0 ± 0.9 nb. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψ pair are measured and compared to theoretical predictions.The production cross-section of J/ψJ/\psi pairs is measured using a data sample of pppp collisions collected by the LHCb experiment at a centre-of-mass energy of s=13 TeV\sqrt{s} = 13 \,{\mathrm{TeV}}, corresponding to an integrated luminosity of 279±11 pb−1279 \pm 11 \,{\mathrm{pb^{-1}}}. The measurement is performed for J/ψJ/\psi mesons with a transverse momentum of less than 10 GeV/c10 \,{\mathrm{GeV}}/c in the rapidity range 2.0<y<4.52.0<y<4.5. The production cross-section is measured to be 15.2±1.0±0.9 nb15.2 \pm 1.0 \pm 0.9 \,{\mathrm{nb}}. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψJ/\psi pair are measured and compared to theoretical predictions

    Measurement of forward W→eÎœW\to e\nu production in pppp collisions at s=8 \sqrt{s}=8\,TeV

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    A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{align*} \begin{split} \sigma_{W^{+} \to e^{+}\nu_{e}}&=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb},\\ \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}&=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{split} \end{align*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{align*} \begin{split} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{split} \end{align*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{equation*} \sigma_{W^{+} \to e^{+}\nu_{e}}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb}, \end{equation*} \begin{equation*} \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{equation*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{equation*} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{equation*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W → eÎœ production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb−1^{−1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eÎœ, are measured to be σW+→e+Îœe=1124.4±2.1±21.5±11.2±13.0pb, {\sigma}_{W^{+}\to {e}^{+}{\nu}_e}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\kern0.5em \mathrm{p}\mathrm{b}, σW−→e−Μ‟e=809.0±1.9±18.1±7.0±9.4 pb, {\sigma}_{W^{-}\to {e}^{-}{\overline{\nu}}_e}=809.0\pm 1.9\pm 18.1\pm \kern0.5em 7.0\pm \kern0.5em 9.4\,\mathrm{p}\mathrm{b}, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination

    Measurement of the B0s→Ό+Ό− Branching Fraction and Effective Lifetime and Search for B0→Ό+Ό− Decays

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    A search for the rare decays Bs0→Ό+ÎŒ- and B0→Ό+ÎŒ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4  fb-1. An excess of Bs0→Ό+ÎŒ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→Ό+ÎŒ-)=(3.0±0.6-0.2+0.3)×10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→Ό+ÎŒ- effective lifetime, τ(Bs0→Ό+ÎŒ-)=2.04±0.44±0.05  ps, is reported. No significant excess of B0→Ό+ÎŒ- decays is found, and a 95% confidence level upper limit, B(B0→Ό+ÎŒ-)<3.4×10-10, is determined. All results are in agreement with the standard model expectations.A search for the rare decays Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- and B0→Ό+Ό−B^0\to\mu^+\mu^- is performed at the LHCb experiment using data collected in pppp collisions corresponding to a total integrated luminosity of 4.4 fb−1^{-1}. An excess of Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→Ό+Ό−)=(3.0±0.6−0.2+0.3)×10−9{\cal B}(B^0_s\to\mu^+\mu^-)=\left(3.0\pm 0.6^{+0.3}_{-0.2}\right)\times 10^{-9}, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→Ό+Ό−B^0_s\to\mu^+\mu^- effective lifetime, τ(Bs0→Ό+Ό−)=2.04±0.44±0.05\tau(B^0_s\to\mu^+\mu^-)=2.04\pm 0.44\pm 0.05 ps, is reported. No significant excess of B0→Ό+Ό−B^0\to\mu^+\mu^- decays is found and a 95 % confidence level upper limit, B(B0→Ό+Ό−)<3.4×10−10{\cal B}(B^0\to\mu^+\mu^-)<3.4\times 10^{-10}, is determined. All results are in agreement with the Standard Model expectations

    Measurements of prompt charm production cross-sections in pp collisions at s=5 \sqrt{s}=5 TeV

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    Production cross-sections of prompt charm mesons are measured using data from pppp collisions at the LHC at a centre-of-mass energy of 5 5\,TeV. The data sample corresponds to an integrated luminosity of 8.60±0.33 8.60\pm0.33\,pb−1^{-1} collected by the LHCb experiment. The production cross-sections of D0D^0, D+D^+, Ds+D_s^+, and D∗+D^{*+} mesons are measured in bins of charm meson transverse momentum, pTp_{\text{T}}, and rapidity, yy. They cover the rapidity range 2.0<y<4.52.0 < y < 4.5 and transverse momentum ranges 0<pT<10 GeV/c0 < p_{\text{T}} < 10\, \text{GeV}/c for D0D^0 and D+D^+ and 1<pT<10 GeV/c1 < p_{\text{T}} < 10\, \text{GeV}/c for Ds+D_s^+ and D∗+D^{*+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1<pT<8 GeV/c1 < p_{\text{T}} < 8\, \text{GeV}/c are determined to be \begin{equation*} \sigma(pp\rightarrow D^0 X) = 1190 \pm 3 \pm 64\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D^+ X) = 456 \pm 3 \pm 34\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D_s^+ X) = 195 \pm 4 \pm 19\,\mu\text{b} \end{equation*} \begin{equation*} \sigma(pp\rightarrow D^{*+} X)= 467 \pm 6 \pm 40\,\mu\text{b} \end{equation*} where the uncertainties are statistical and systematic, respectively.Production cross-sections of prompt charm mesons are measured using data from pp collisions at the LHC at a centre-of-mass energy of 5 TeV. The data sample corresponds to an integrated luminosity of 8.60 ± 0.33 pb−1^{−1} collected by the LHCb experiment. The production cross-sections of D0^{0}, D+^{+}, Ds+_{s}^{+} , and D∗+^{∗+} mesons are measured in bins of charm meson transverse momentum, pT_{T}, and rapidity, y. They cover the rapidity range 2.0 < y < 4.5 and transverse momentum ranges 0 < pT_{T} < 10 GeV/c for D0^{0} and D+^{+} and 1 < pT_{T} < 10 GeV/c for Ds+_{s}^{+} and D∗+^{∗+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1 < pT_{T} < 8 GeV/c are determined to be σ(pp→D0X)=1004±3±54ÎŒb,σ(pp→D+X)=402±2±30ÎŒb,σ(pp→Ds+X)=170±4±16ÎŒb,σ(pp→D∗+X)=421±5±36ÎŒb, \begin{array}{l}\sigma \left( pp\to {D}^0X\right)=1004\pm 3\pm 54\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}^{+}X\right)=402\pm 2\pm 30\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}_s^{+}X\right)=170\pm 4\pm 16\mu \mathrm{b},\\ {}\sigma \left( pp\to {D}^{\ast +}X\right)=421\pm 5\pm 36\mu \mathrm{b},\end{array} where the uncertainties are statistical and systematic, respectively.Production cross-sections of prompt charm mesons are measured using data from pppp collisions at the LHC at a centre-of-mass energy of 5 5\,TeV. The data sample corresponds to an integrated luminosity of 8.60±0.33 8.60\pm0.33\,pb−1^{-1} collected by the LHCb experiment. The production cross-sections of D0D^0, D+D^+, Ds+D_s^+, and D∗+D^{*+} mesons are measured in bins of charm meson transverse momentum, pTp_{\text{T}}, and rapidity, yy. They cover the rapidity range 2.0<y<4.52.0<y<4.5 and transverse momentum ranges 0<pT<10 GeV/c0 < p_{\text{T}} < 10\, \text{GeV}/c for D0D^0 and D+D^+ and 1<pT<10 GeV/c1 < p_{\text{T}} < 10\, \text{GeV}/c for Ds+D_s^+ and D∗+D^{*+} mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1<pT<8 GeV/c1 < p_{\text{T}} < 8\, \text{GeV}/c are determined to be \sigma(pp\rightarrow D^0 X) = 1004 \pm 3 \pm 54\,\mu\text{b} \sigma(pp\rightarrow D^+ X) = 402 \pm 2 \pm 30\,\mu\text{b} \sigma(pp\rightarrow D_s^+ X) = 170 \pm 4 \pm 16\,\mu\text{b} \sigma(pp\rightarrow D^{*+} X)= 421 \pm 5 \pm 36\,\mu\text{b} where the uncertainties are statistical and systematic, respectively

    Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

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    Flow harmonic coefficients, v n , which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV . The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features

    A stochastic version of Zeeman's market model

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    A Stochastic Version of Zeeman's Market Model

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    In a heterogenous agents framework, we study a randomized version of Zeeman's market model with fundamental and momentum traders. Using methods from random dynamical systems theory, we examine convergence properties of invariant measures which correspond to market equilibria. It turns out that due to a stochastic stabilisation effect the market stays stable up to some critical value of speculative activity. If this threshold is surpassed, sudden trend reversals are possible without being induced by some exogenous shock.

    Bifurcation of One-Dimensional Stochastic Differential Equation

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    We consider families of random dynamical systems induced by parametrized one dimensional stochastic differential equations. We give necessary and sufficient conditions on the invariant measures of the associated Markov semigroups which ensure a stochastic bifurcation. This leads to sufficient conditions on drift and diffusion coefficients for a stochastic pitchfork and transcritical bifurcation of the family of random dynamical systems
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