يعرض 1 - 10 نتائج من 281 نتيجة بحث عن '"D. Fouchez"', وقت الاستعلام: 1.25s تنقيح النتائج
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    دورية أكاديمية

    المصدر: The Astrophysical Journal, Vol 948, Iss 1, p 10 (2023)

    الوصف: We apply the color–magnitude intercept calibration method (CMAGIC) to the Nearby Supernova Factory SNe Ia spectrophotometric data set. The currently existing CMAGIC parameters are the slope and intercept of a straight line fit to the linear region in the color–magnitude diagram, which occurs over a span of approximately 30 days after maximum brightness. We define a new parameter, ω _XY , the size of the “bump” feature near maximum brightness for arbitrary filters X and Y . We find a significant correlation between the slope of the linear region, β _XY , in the CMAGIC diagram and ω _XY . These results may be used to our advantage, as they are less affected by extinction than parameters defined as a function of time. Additionally, ω _XY is computed independently of templates. We find that current empirical templates are successful at reproducing the features described in this work, particularly SALT3, which correctly exhibits the negative correlation between slope and “bump” size seen in our data. In 1D simulations, we show that the correlation between the size of the “bump” feature and β _XY can be understood as a result of chemical mixing due to large-scale Rayleigh–Taylor instabilities.

    وصف الملف: electronic resource

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    تقرير
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    المساهمون: Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-19-CE31-0023,DEEPDIP,Apprentissage profond pour les grands programmes d'imagerie(2019)

    المصدر: Astronomy and Astrophysics-A&A
    Astronomy and Astrophysics-A&A, 2022, 662, pp.A36. ⟨10.1051/0004-6361/202142751⟩

    الوصف: Deep Learning models have been increasingly exploited in astrophysical studies, yet such data-driven algorithms are prone to producing biased outputs detrimental for subsequent analyses. In this work, we investigate two major forms of biases, i.e., class-dependent residuals and mode collapse, in a case study of estimating photometric redshifts as a classification problem using Convolutional Neural Networks (CNNs) and galaxy images with spectroscopic redshifts. We focus on point estimates and propose a set of consecutive steps for resolving the two biases based on CNN models, involving representation learning with multi-channel outputs, balancing the training data and leveraging soft labels. The residuals can be viewed as a function of spectroscopic redshifts or photometric redshifts, and the biases with respect to these two definitions are incompatible and should be treated in a split way. We suggest that resolving biases in the spectroscopic space is a prerequisite for resolving biases in the photometric space. Experiments show that our methods possess a better capability in controlling biases compared to benchmark methods, and exhibit robustness under varying implementing and training conditions provided with high-quality data. Our methods have promises for future cosmological surveys that require a good constraint of biases, and may be applied to regression problems and other studies that make use of data-driven models. Nonetheless, the bias-variance trade-off and the demand on sufficient statistics suggest the need for developing better methodologies and optimizing data usage strategies.
    29 pages, 12+11 figures, 2+3 tables; accepted in Astronomy & Astrophysics

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    المساهمون: Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de Calcul de l'IN2P3 (CC-IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de physique des gaz et des plasmas (LPGP), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Institut de recherche en astrophysique et planétologie (IRAP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2020-....] (UGA [2020-....])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes [2020-....] (UGA [2020-....])

    المصدر: Monthly Notices of the Royal Astronomical Society
    Monthly Notices of the Royal Astronomical Society, 2021, 501 (3), pp.3272-3288. ⟨10.1093/mnras/staa3602⟩
    Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2021, 501 (3), pp.3272-3288. ⟨10.1093/mnras/staa3602⟩

    الوصف: Fink is a broker designed to enable science with large time-domain alert streams such as the one from the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). It exhibits traditional astronomy broker features such as automatised ingestion, annotation, selection and redistribution of promising alerts for transient science. It is also designed to go beyond traditional broker features by providing real-time transient classification which is continuously improved by using state-of-the-art Deep Learning and Adaptive Learning techniques. These evolving added values will enable more accurate scientific output from LSST photometric data for diverse science cases while also leading to a higher incidence of new discoveries which shall accompany the evolution of the survey. In this paper we introduce Fink, its science motivation, architecture and current status including first science verification cases using the Zwicky Transient Facility alert stream.
    Comment: accepted in MNRAS

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    المساهمون: Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Nearby Supernova factory, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

    المصدر: Astronomy and Astrophysics-A&A
    Astronomy and Astrophysics-A&A, 2020, 636, pp.A46. ⟨10.1051/0004-6361/201834954⟩
    Astronomy and astrophysics 636, A46-(2020). doi:10.1051/0004-6361/201834954
    Astron.Astrophys.
    Astron.Astrophys., 2020, 636, pp.A46. ⟨10.1051/0004-6361/201834954⟩
    Astronomy & Astrophysics

    الوصف: Type Ia Supernovae (SNe Ia) are widely used to measure the expansion of the Universe. Improving distance measurements of SNe Ia is one technique to better constrain the acceleration of expansion and determine its physical nature. This document develops a new SNe Ia spectral energy distribution (SED) model, called the SUpernova Generator And Reconstructor (SUGAR), which improves the spectral description of SNe Ia, and consequently could improve the distance measurements. This model is constructed from SNe Ia spectral properties and spectrophotometric data from The Nearby Supernova Factory collaboration. In a first step, a PCA-like method is used on spectral features measured at maximum light, which allows us to extract the intrinsic properties of SNe Ia. Next, the intrinsic properties are used to extract the average extinction curve. Third, an interpolation using Gaussian Processes facilitates using data taken at different epochs during the lifetime of a SN Ia and then projecting the data on a fixed time grid. Finally, the three steps are combined to build the SED model as a function of time and wavelength. This is the SUGAR model. The main advancement in SUGAR is the addition of two additional parameters to characterize SNe Ia variability. The first is tied to the properties of SNe Ia ejecta velocity, the second is correlated with their calcium lines. The addition of these parameters, as well as the high quality the Nearby Supernova Factory data, makes SUGAR an accurate and efficient model for describing the spectra of normal SNe Ia as they brighten and fade. The performance of this model makes it an excellent SED model for experiments like ZTF, LSST or WFIRST.
    25 pages, 27 figures

    وصف الملف: application/pdf

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    دورية أكاديمية

    المؤلفون: S. Schael, R. Barate, R. Brunelière, I. De Bonis, D. Decamp, C. Goy, S. Jézéquel, J. -P. Lees, F. Martin, E. Merle, M. -N. Minard, B. Pietrzyk, B. Trocmé, S. Bravo, M. P. Casado, M. Chmeissani, J. M. Crespo, E. Fernandez, M. Fernandez-Bosman, Ll. Garrido, M. Martinez, A. Pacheco, H. Ruiz, A. Colaleo, D. Creanza, N. De Filippis, M. de Palma, G. Iaselli, G. Maggi, M. Maggi, S. Nuzzo, A. Ranieri, G. Raso, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, A. Tricomi, G. Zito, X. Huang, J. Lin, Q. Ouyang, T. Wang, Y. Xie, R. Xu, S. Xue, J. Zhang, L. Zhang, W. Zhao, D. Abbaneo, T. Barklow, O. Buchmüller, M. Cattaneo, B. Clerbaux, H. Drevermann, R. W. Forty, M. Frank, F. Gianotti, J. B. Hansen, J. Harvey, D. E. Hutchcroft, P. Janot, B. Jost, M. Kado, P. Mato, A. Moutoussi, F. Ranjard, L. Rolandi, D. Schlatter, F. Teubert, A. Valassi, I. Videau, F. Badaud, S. Dessagne, A. Falvard, D. Fayolle, P. Gay, J. Jousset, B. Michel, S. Monteil, D. Pallin, J. M. Pascolo, P. Perret, J. D. Hansen, J. R. Hansen, P. H. Hansen, A. C. Kraan, B. S. Nilsson, A. Kyriakis, C. Markou, E. Simopoulou, A. Vayaki, K. Zachariadou, A. Blondel, J. -C. Brient, F. Machefert, A. Rougé, H. Videau, V. Ciulli, E. Focardi, G. Parrini, A. Antonelli, M. Antonelli, G. Bencivenni, F. Bossi, G. Capon, F. Cerutti, V. Chiarella, P. Laurelli, G. Mannocchi, G. P. Murtas, L. Passalacqua, J. Kennedy, J. G. Lynch, P. Negus, V. O’Shea, A. S. Thompson, S. Wasserbaech, R. Cavanaugh, S. Dhamotharan, C. Geweniger, P. Hanke, V. Hepp, E. E. Kluge, A. Putzer, H. Stenzel, K. Tittel, M. Wunsch, R. Beuselinck, W. Cameron, G. Davies, P. J. Dornan, M. Girone, N. Marinelli, J. Nowell, S. A. Rutherford, J. K. Sedgbeer, J. C. Thompson, R. White, V. M. Ghete, P. Girtler, E. Kneringer, D. Kuhn, G. Rudolph, E. Bouhova-Thacker, C. K. Bowdery, D. P. Clarke, G. Ellis, A. J. Finch, F. Foster, G. Hughes, R. W. L. Jones, M. R. Pearson, N. A. Robertson, T. Sloan, M. Smizanska, O. van der Aa, C. Delaere, G. Leibenguth, V. Lemaitre, U. Blumenschein, F. Hölldorfer, K. Jakobs, F. Kayser, A. -S. Müller, B. Renk, H. -G. Sander, S. Schmeling, H. Wachsmuth, C. Zeitnitz, T. Ziegler, A. Bonissent, P. Coyle, C. Curtil, A. Ealet, D. Fouchez, P. Payre, A. Tilquin, F. Ragusa, A. David, H. Dietl, G. Ganis, K. Hüttmann, G. Lütjens, W. Männer, H. -G. Moser, R. Settles, M. Villegas, G. Wolf, J. Beacham, K. Cranmer, I. Yavin, J. Boucrot, O. Callot, M. Davier, L. Duflot, J. -F. Grivaz, Ph. Heusse, A. Jacholkowska, L. Serin, J. -J. Veillet, P. Azzurri, G. Bagliesi, T. Boccali, L. Foà, A. Giammanco, A. Giassi, F. Ligabue, A. Messineo, F. Palla, G. Sanguinetti, A. Sciabà, G. Sguazzoni, P. Spagnolo, R. Tenchini, A. Venturi, P. G. Verdini, O. Awunor, G. A. Blair, G. Cowan, A. Garcia-Bellido, M. G. Green, T. Medcalf, A. Misiejuk, J. A. Strong, P. Teixeira-Dias, R. W. Clifft, T. R. Edgecock, P. R. Norton, I. R. Tomalin, J. J. Ward, B. Bloch-Devaux, D. Boumediene, P. Colas, B. Fabbro, E. Lançon, M. -C. Lemaire, E. Locci, P. Perez, J. Rander, B. Tuchming, B. Vallage, A. M. Litke, G. Taylor, C. N. Booth, S. Cartwright, F. Combley, P. N. Hodgson, M. Lehto, L. F. Thompson, A. Böhrer, S. Brandt, C. Grupen, J. Hess, A. Ngac, G. Prange, C. Borean, G. Giannini, H. He, J. Putz, J. Rothberg, S. R. Armstrong, K. Berkelman, D. P. S. Ferguson, Y. Gao, S. González, O. J. Hayes, H. Hu, S. Jin, J. Kile, P. A. McNamaraIII, J. Nielsen, Y. B. Pan, J. H. von Wimmersperg-Toeller, W. Wiedenmann, J. Wu, Sau Lan Wu, X. Wu, G. Zobernig, G. Dissertori

    المساهمون: Schael, S., Barate, R., Brunelière, R., De Bonis, I., Decamp, D., Goy, C., Jézéquel, S., Lees, J. -P., Martin, F., Merle, E., Minard, M. -N., Pietrzyk, B., Trocmé, B., Bravo, S., Casado, M. P., Chmeissani, M., Crespo, J. M., Fernandez, E., Fernandez-Bosman, M., Garrido, Ll., Martinez, M., Pacheco, A., Ruiz, H., Colaleo, A., Creanza, D., De Filippis, N., de Palma, M., Iaselli, G., Maggi, G., Maggi, M., Nuzzo, S., Ranieri, A., Raso, G., Ruggieri, F., Selvaggi, G., Silvestris, L., Tempesta, P., Tricomi, A., Zito, G., Huang, X., Lin, J., Ouyang, Q., Wang, T., Xie, Y., Xu, R., Xue, S., Zhang, J., Zhang, L., Zhao, W., Abbaneo, D., Barklow, T., Buchmüller, O., Cattaneo, M., Clerbaux, B., Drevermann, H., Forty, R. W., Frank, M., Gianotti, F., Hansen, J. B., Harvey, J., Hutchcroft, D. E., Janot, P., Jost, B., Kado, M., Mato, P., Moutoussi, A., Ranjard, F., Rolandi, L., Schlatter, D., Teubert, F., Valassi, A., Videau, I., Badaud, F., Dessagne, S., Falvard, A., Fayolle, D., Gay, P., Jousset, J., Michel, B., Monteil, S., Pallin, D., Pascolo, J. M., Perret, P., Hansen, J. D., Hansen, J. R., Hansen, P. H., Kraan, A. C., Nilsson, B. S., Kyriakis, A., Markou, C., Simopoulou, E., Vayaki, A., Zachariadou, K., Blondel, A., Brient, J. -C., Machefert, F., Rougé, A., Videau, H., Ciulli, V., Focardi, E.

    مصطلحات موضوعية: e plus -e- Experiments

    الوصف: A search for the production and non-standard decay of a Higgs boson, h, into four taus through intermediate pseudoscalars, a, is conducted on 683 pb(-1) of data collected by the ALEPH experiment at centre-of-mass energies from 183 to 209 GeV. No excess of events above background is observed, and exclusion limits are placed on the combined production cross section times branching ratio, xi(2) = sigma(e(+)e(-)-> Zh)/sigma SM(e+e--> Zh) x B(h -> aa) x B(a -> tau(+)tau(-))(2.) For m(h) < 107 GeV / c(2) and 4 < m(a) 10 GeV / c(2) , xi(2) > 1 is excluded at the 95% confidence level.

    وصف الملف: STAMPA

    العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:000278250000059; issue:5; numberofpages:19; journal:JOURNAL OF HIGH ENERGY PHYSICS; http://hdl.handle.net/11589/2772Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-77954967668

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    دورية أكاديمية

    المساهمون: The Pennsylvania State University CiteSeerX Archives

    الوصف: We use three years of data from the Supernova Legacy Survey (SNLS) to study the general properties of core-collapse and type Ia supernovae. This is the first such study using the “rolling search ” technique which guarantees well-sampled SNLS light curves and good efficiency for supernovae brighter than i ′ ∼ 24. Using host photometric redshifts, we measure the supernova absolute magnitude distribution down to luminosities 4.5 mag fainter than normal SNIa. Using spectroscopy and light-curve fitting to discriminate against

    وصف الملف: application/pdf