1,135 research outputs found
Model Extraction Warning in MLaaS Paradigm
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
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
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
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
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
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
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
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
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
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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