1,135 research outputs found

    Model Extraction Warning in MLaaS Paradigm

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    Cloud vendors are increasingly offering machine learning services as part of their platform and services portfolios. These services enable the deployment of machine learning models on the cloud that are offered on a pay-per-query basis to application developers and end users. However recent work has shown that the hosted models are susceptible to extraction attacks. Adversaries may launch queries to steal the model and compromise future query payments or privacy of the training data. In this work, we present a cloud-based extraction monitor that can quantify the extraction status of models by observing the query and response streams of both individual and colluding adversarial users. We present a novel technique that uses information gain to measure the model learning rate by users with increasing number of queries. Additionally, we present an alternate technique that maintains intelligent query summaries to measure the learning rate relative to the coverage of the input feature space in the presence of collusion. Both these approaches have low computational overhead and can easily be offered as services to model owners to warn them of possible extraction attacks from adversaries. We present performance results for these approaches for decision tree models deployed on BigML MLaaS platform, using open source datasets and different adversarial attack strategies

    Flat Currents in the Classical AdS_5 x S^5 Pure Spinor Superstring

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    It is proven that the classical pure spinor superstring in an AdS_5 x S^5 background has a flat current depending on a continuous parameter. This generalizes the recent result of Bena, et al. for the classical Green-Schwarz superstring.Comment: 10 pages, 1 figure, harvma

    Conformal Invariance of the Pure Spinor Superstring in a Curved Background

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    It is shown that the pure spinor formulation of the heterotic superstring in a generic gravitational and super Yang-Mills background has vanishing one-loop beta functions.Comment: Reference adde

    One Loop Conformal Invariance of the Superstring in an AdS_5 x S^5 Background

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    It is proven that the pure spinor superstring in an AdS_5 x S^5 background remains conformally invariant at one loop level in the sigma model perturbation theory.Comment: 14 pages harvma

    A semi-lagrangian scheme for hamilton-jacobi-bellman equations on networks

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    We present a semi-Lagrangian scheme for the approximation of a class of Hamilton- Jacobi-Bellman (HJB) equations on networks. The scheme is explicit, consistent, and stable for large time steps. We prove a convergence result and two error estimates. For an HJB equation with space-independent Hamiltonian, we obtain a first order error estimate. In the general case, we provide, under a hyperbolic CFL condition, a convergence estimate of order one half. The theoretical results are discussed and validated in a numerical tests section

    Covariant N=2 heterotic string in four dimensions

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    We construct a covariant formulation of the heterotic superstring on K3 times T^2 with manifest N=2 supersymmetry. We show how projective superspace appears naturally in the hybrid formulation giving a (partially) geometric interpretation of the harmonic parameter. The low-energy effective action for this theory is given by a non-standard form of N=2 supergravity which is intimately related to the N=1 old-minimal formulation. This formalism can be used to derive new descriptions of interacting projective superspace field theories using Berkovits' open string field theory and the the heterotic Berkovits-Okawa-Zwiebach construction.Comment: 11+3 page

    A new genus and species of Planopinae (Xenarthra: Tardigrada) from the Miocene of Santa Cruz Province, Argentina

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    Prepoplanops boleadorensis, a new genus and species of Planopinae (Xenarthra, Tardigrada), is described herein. The new taxon is based on a nearly complete specimen recovered from the Cerro Boleadoras Formation (Miocene, RĂ­o Zeballos Group), in northwestern Santa Cruz Province, Argentina. The shape and length of the predentary region of the skull and the length of the diastema of Prepoplanops boleadorensis differ from those present in the species of Planops. The posterolateral opening of the mandibular canal and the position of the posterior margin of the mandibular symphysis differ from those of species of Prepotherium. In addition, Prepoplanops boleadorensis differs from Planops martini in the size of the humeral tuberosities, the development of the deltoid crest, the position of the distal margin of the humeral trochlea, the shape and position of the olecranon, the development of the femoral epicondyles, and the shape of the medial margins of the patellar trochlea and medial condyle. On the other hand, it differs from Prepotherium potens in the shape of the medial margin of the medial condyle. The recognition of Prepoplanops boleadorensis increases the diversity of Planopinae for the Miocene of Patagonia, Argentina.Fil: Carlini, Alfredo Armando. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn PaleontologĂ­a Vertebrados; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Brandoni, Diego. Provincia de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Universidad AutĂłnoma de Entre RĂ­os. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - Santa Fe. Centro de Investigaciones CientĂ­ficas y Transferencia de TecnologĂ­a a la ProducciĂłn; ArgentinaFil: Dal Molin, Carlos N.. SecretarĂ­a de Industria y MinerĂ­a. Servicio GeolĂłgico Minero Argentino; Argentin

    On the Non-renormalization of the AdS Radius

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    We show that the relation between the 't Hooft coupling and the radius of AdS is not renormalized at one-loop in the sigma model perturbation theory. We prove this by computing the quantum effective action for the superstring on AdS_5 x S^5 and showing that it does not receive any finite alpha' corrections. We also show that the central charge of the interacting worldsheet conformal field theory vanishes at one-loop.Comment: 13 pages, harvmac. v2: refs added, version to be published on JHE

    Plunging ranula in children: case report and literature review

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    Few cases of plunging ranulas (PRs) occur during childhood and the lesions are frequently misdiagnosed. Here, a PR in a child is reported along with a literature review. A seven-year-old female complaining of swelling in the midline neck, left-submandibular region, was evaluated. No oral cavity or major salivary glands abnormalities were detected. On palpation a soft, painless, and fluid-containing mass was observed. The suspicion PR was performed by ultrasound. The diagnosis was confirmed with a histopathological examination. The lesion was removed with a cervical approach, without recurrence. PR is an uncommon condition in children under 10 years of age. Differential diagnosis depends on clinical examination and ultrasonography. A computed tomography-scan and magnetic resonance imaging can be performed if the diagnosis remains uncertain. In pediatrics, the key to success of the treatment may rely on the radical excision of the cyst and sublingual gland, via an intraoral or submandibular approach

    Hybrid Formalism, Supersymmetry Reduction, and Ramond-Ramond Fluxes

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    The supersymmetric hybrid formalism for Type II strings is used to study partial supersymmetry breaking in four and three dimensions. We use worldsheet techniques to derive effects of internal Ramond-Ramond fluxes such as torsions, superpotentials and warping.Comment: Harvmac. No figure
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