658 research outputs found

    Heterogeneous Face Recognition with CNNs

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    International audienceHeterogeneous face recognition aims to recognize faces across different sensor modalities. Typically, gallery images are normal visible spectrum images, and probe images are infrared images or sketches. Recently significant improvements in visible spectrum face recognition have been obtained by CNNs learned from very large training datasets. In this paper, we are interested in the question to what extent the features from a CNN pre-trained on visible spectrum face images can be used to perform heterogeneous face recognition. We explore different metric learning strategies to reduce the discrepancies between the different modalities. Experimental results show that we can use CNNs trained on visible spectrum images to obtain results that are on par or improve over the state-of-the-art for heterogeneous recognition with near-infrared images and sketches

    Dynamics of Line-Driven Winds from Disks in Cataclysmic Variables. I. Solution Topology and Wind Geometry

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    We analyze the dynamics of 2-D stationary, line-driven winds from accretion disks in cataclysmic variable stars. The driving force is that of line radiation pressure, in the formalism developed by Castor, Abbott & Klein for O stars. Our main assumption is that wind helical streamlines lie on straight cones. We find that the Euler equation for the disk wind has two eigenvalues, the mass loss rate and the flow tilt angle with the disk. Both are calculated self-consistently. The wind is characterized by two distinct regions, an outer wind launched beyond four white dwarf radii from the rotation axis, and an inner wind launched within this radius. The inner wind is very steep, up to 80 degrees with the disk plane, while the outer wind has a typical tilt of 60 degrees. In both cases the ray dispersion is small. We, therefore, confirm the bi-conical geometry of disk winds as suggested by observations and kinematical modeling. The wind collimation angle appears to be robust and depends only on the disk temperature stratification. The flow critical points lie high above the disk for the inner wind, but close to the disk photosphere for the outer wind. Comparison with existing kinematical and dynamical models is provided. Mass loss rates from the disk as well as wind velocity laws are discussed in a subsequent paper.Comment: 21 pages, 10 Postscript figures; available also from http://www.pa.uky.edu/~shlosman/publ.html. Astrophysical Journal, submitte

    Fusion of Intra- and Inter-modality Algorithms for Face-Sketch Recognition

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    All solutions of the localization equations for N=2 quantum black hole entropy

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    We find the most general bosonic solution to the localization equations describing the contributions to the quantum entropy of supersymmetric black holes in four-dimensional N=2 supergravity coupled to n_v vector multiplets. This requires the analysis of the BPS equations of the corresponding off-shell supergravity (including fluctuations of the auxiliary fields) with AdS2 \times S2 attractor boundary conditions. Our work completes and extends the results of arXiv:1012.0265 that were obtained for the vector multiplet sector, to include the fluctuations of all the fields of the off-shell supergravity. We find that, when the auxiliary SU(2) gauge field strength vanishes, the most general supersymmetric configuration preserving four supercharges is labelled by n_v+1 real parameters corresponding to the excitations of the conformal mode of the graviton and the scalars of the n_v vector multiplets. In the general case, the localization manifold is labelled by an additional SU(2) triplet of one-forms and a scalar function.Comment: 27 page

    BézierSketch: A Generative Model for Scalable Vector Sketches

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    The study of neural generative models of human sketches is a fascinating contemporary modeling problem due to the links between sketch image generation and the human drawing process. The landmark SketchRNN provided breakthrough by sequentially generating sketches as a sequence of waypoints. However this leads to low-resolution image generation, and failure to model long sketches. In this paper we present B\'ezierSketch, a novel generative model for fully vector sketches that are automatically scalable and high-resolution. To this end, we first introduce a novel inverse graphics approach to stroke embedding that trains an encoder to embed each stroke to its best fit B\'ezier curve. This enables us to treat sketches as short sequences of paramaterized strokes and thus train a recurrent sketch generator with greater capacity for longer sketches, while producing scalable high-resolution results. We report qualitative and quantitative results on the Quick, Draw! benchmark.Comment: Accepted as poster at ECCV 202

    de Sitter Supersymmetry Revisited

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    We present the basic N=1\mathcal{N} =1 superconformal field theories in four-dimensional de Sitter space-time, namely the non-abelian super Yang-Mills theory and the chiral multiplet theory with gauge interactions or cubic superpotential. These theories have eight supercharges and are invariant under the full SO(4,2)SO(4,2) group of conformal symmetries, which includes the de Sitter isometry group SO(4,1)SO(4,1) as a subgroup. The theories are ghost-free and the anti-commutator α{Qα,Qα}\sum_\alpha\{Q_\alpha, Q^{\alpha\dagger}\} is positive. SUSY Ward identities uniquely select the Bunch-Davies vacuum state. This vacuum state is invariant under superconformal transformations, despite the fact that de Sitter space has non-zero Hawking temperature. The N=1\mathcal{N}=1 theories are classically invariant under the SU(2,21)SU(2,2|1) superconformal group, but this symmetry is broken by radiative corrections. However, no such difficulty is expected in the N=4\mathcal{N}=4 theory, which is presented in appendix B.Comment: 21 pages, 2 figure

    The impact of a ten-week physical exercise program on health-related quality of life in patients with inflammatory bowel disease: A prospective randomized controlled trial

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    BACKGROUND Improving health-related quality of life is a primary target of therapy for patients with inflammatory bowel disease. Physical activity has been demonstrated to improve health-related quality of life in several patient populations with chronic disease. There are very few studies investigating the effects of physical activity on health-related quality of life in inflammatory bowel disease. The primary purpose of this study is to investigate the effects of 10 weeks of moderate physical activity on health-related quality of life in patients with inflammatory bowel disease. METHODS Thirty patients with mild to moderate IBD (Crohn's Disease Activity Index (CDAI) \textless220 or Rachmilewitz Index (RI) \textless11) were randomized 1:1 to either supervised moderate-intensity running thrice a week for 10 weeks or a control group who were not prescribed any exercise. Health-related quality of life, symptoms, and inflammation were assessed at baseline and after 10 weeks. RESULTS Participants were 41 ± 14 years (73% female), had a body mass index of 22.8 ± 4.1 kg/m(2), and an average CDAI or RI of 66.8 ± 42.4 and 3.6 ± 3.1. No adverse events occurred during the 10-week training period. Health-related quality of life, reported as IBDQ total score, improved 19% in the intervention group and 8% in the control group. Scores for the IBDQ social sub-scale were significantly improved in the intervention group compared with controls (\textgreekDIBDQsocial = 6.27 ± 5.46 vs. 1.87 ± 4.76, p = 0.023). CONCLUSION Patients suffering from moderately active IBD are capable of performing symptom-free regular endurance exercise. Our data support the assumption that PA is feasible in IBD patients. PA may furthermore improve quality of life through improvements in social well-being, and may, therefore, be a useful adjunct to IBD therapy

    Ferredoxin:NADP(H) Oxidoreductase Abundance and Location Influences Redox Poise and Stress Tolerance

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    In linear photosynthetic electron transport, ferredoxin:NADP(H) oxidoreductase (FNR) transfers electrons from ferredoxin (Fd) to NADP(+). Both NADPH and reduced Fd (Fd(red)) are required for reductive assimilation and light/dark activation/deactivation of enzymes. FNR is therefore a hub, connecting photosynthetic electron transport to chloroplast redox metabolism. A correlation between FNR content and tolerance to oxidative stress is well established, although the precise mechanism remains unclear. We investigated the impact of altered FNR content and localization on electron transport and superoxide radical evolution in isolated thylakoids, and probed resulting changes in redox homeostasis, expression of oxidative stress markers, and tolerance to high light in planta. Our data indicate that the ratio of Fd(red) to FNR is critical, with either too much or too little FNR potentially leading to increased superoxide production, and perception of oxidative stress at the level of gene transcription. In FNR overexpressing plants, which show more NADP(H) and glutathione pools, improved tolerance to high-light stress indicates that disturbance of chloroplast redox poise and increased free radical generation may help “prime” the plant and induce protective mechanisms. In fnr1 knock-outs, the NADP(H) and glutathione pools are more oxidized relative to the wild type, and the photoprotective effect is absent despite perception of oxidative stress at the level of gene transcription

    Hydrodynamic Models of Line-Driven Accretion Disk Winds III: Local Ionization Equilibrium

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    We present time-dependent numerical hydrodynamic models of line-driven accretion disk winds in cataclysmic variable systems and calculate wind mass-loss rates and terminal velocities. The models are 2.5-dimensional, include an energy balance condition with radiative heating and cooling processes, and includes local ionization equilibrium introducing time dependence and spatial dependence on the line radiation force parameters. The radiation field is assumed to originate in an optically thick accretion disk. Wind ion populations are calculated under the asumption that local ionization equilibrium is determined by photoionization and radiative recombination, similar to a photoionized nebula. We find a steady wind flowing from the accretion disk. Radiative heating tends to maintain the temperature in the higher density wind regions near the disk surface, rather than cooling adiabatically. For a disk luminosity Ldisk = Lsun, white dwarf mass Mwd = 0.6 Msun, and white dwarf radii Rwd = 0.01 Rsun, we obtain a wind mass-loss rate of dMwind/dt =4E-12 Msun/yr, and a terminal velocity of ~ 3000 km/s. These results confirm the general velocity and density tructures found in our earlier constant ionization equilibrium adiabatic CV wind models. Further we establish here 2.5D numerical models that can be extended to QSO/AGN winds where the local ionization equilibrium will play a crucial role in the overall dynamics.Comment: 43 pages, 12 figures, to be published in The Astrophysical Journa
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