3,597 research outputs found

    Real-time single image and video super-resolution using an efficient sub-pixel convolutional neural network

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    Recently, several models based on deep neural networks have achieved great success in terms of both reconstruction accuracy and computational performance for single image super-resolution. In these methods, the low resolution (LR) input image is upscaled to the high resolution (HR) space using a single filter, commonly bicubic interpolation, before reconstruction. This means that the super-resolution (SR) operation is performed in HR space. We demonstrate that this is sub-optimal and adds computational complexity. In this paper, we present the first convolutional neural network (CNN) capable of real-time SR of 1080p videos on a single K2 GPU. To achieve this, we propose a novel CNN architecture where the feature maps are extracted in the LR space. In addition, we introduce an efficient sub-pixel convolution layer which learns an array of upscaling filters to upscale the final LR feature maps into the HR output. By doing so, we effectively replace the handcrafted bicubic filter in the SR pipeline with more complex upscaling filters specifically trained for each feature map, whilst also reducing the computational complexity of the overall SR operation. We evaluate the proposed approach using images and videos from publicly available datasets and show that it performs significantly better (+0.15dB on Images and +0.39dB on Videos) and is an order of magnitude faster than previous CNN-based methods

    Real-time single image and video super-resolution using an efficient sub-pixel convolutional neural network

    Get PDF
    Recently, several models based on deep neural networks have achieved great success in terms of both reconstruction accuracy and computational performance for single image super-resolution. In these methods, the low resolution (LR) input image is upscaled to the high resolution (HR) space using a single filter, commonly bicubic interpolation, before reconstruction. This means that the super-resolution (SR) operation is performed in HR space. We demonstrate that this is sub-optimal and adds computational complexity. In this paper, we present the first convolutional neural network (CNN) capable of real-time SR of 1080p videos on a single K2 GPU. To achieve this, we propose a novel CNN architecture where the feature maps are extracted in the LR space. In addition, we introduce an efficient sub-pixel convolution layer which learns an array of upscaling filters to upscale the final LR feature maps into the HR output. By doing so, we effectively replace the handcrafted bicubic filter in the SR pipeline with more complex upscaling filters specifically trained for each feature map, whilst also reducing the computational complexity of the overall SR operation. We evaluate the proposed approach using images and videos from publicly available datasets and show that it performs significantly better (+0.15dB on Images and +0.39dB on Videos) and is an order of magnitude faster than previous CNN-based methods

    Identities for hyperelliptic P-functions of genus one, two and three in covariant form

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    We give a covariant treatment of the quadratic differential identities satisfied by the P-functions on the Jacobian of smooth hyperelliptic curves of genera 1, 2 and 3

    Measurement of the quenching factor of Na recoils in NaI(Tl)

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    Measurements of the quenching factor for sodium recoils in a 5 cm diameter NaI(Tl) crystal at room temperature have been made at a dedicated neutron facility at the University of Sheffield. The crystal has been exposed to 2.45 MeV mono-energetic neutrons generated by a Sodern GENIE 16 neutron generator, yielding nuclear recoils of energies between 10 and 100 keVnr. A cylindrical BC501A detector has been used to tag neutrons that scatter off sodium nuclei in the crystal. Cuts on pulse shape and time of flight have been performed on pulses recorded by an Acqiris DC265 digitiser with a 2 ns sampling time. Measured quenching factors of Na nuclei range from 19% to 26% in good agreement with other experiments, and a value of 25.2 \pm 6.4% has been determined for 10 keV sodium recoils. From pulse shape analysis, the mean times of pulses from electron and nuclear recoils have been compared down to 2 keVee. The experimental results are compared to those predicted by Lindhard theory, simulated by the SRIM Monte Carlo code, and a preliminary curve calculated by Prof. Akira Hitachi.Comment: 21 pages, 13 figure

    Interaction Between Hot Carrier Aging and PBTI Degradation in nMOSFETs: Characterization, Modelling and Lifetime Prediction

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    Modelling of the interaction between Hot Carrier Aging (HCA) and Positive Bias Temperature Instability (PBTI) has been considered as one of the main challenges in nanoscale CMOS circuit design. Previous works were mainly based on separate HCA and PBTI instead of Interacted HCA-PBTI Degradation (IHPD). The key advance of this work is to develop a methodology that enables accurate modelling of IHPD through understanding the charging/discharging and generation kinetics of different types of defects during the interaction between HCA and PBTI. It is found that degradation during alternating HCA and PBTI stress cannot be modelled by independent HCI/PBTI. Different stress sequence, i.e. HCA-PBTI-HCA and PBTI-HCA-PBTI, lead to completely different degradation kinetics. Based on the Cyclic Anti-neutralization Model (CAM), for the first time, IHPD has been accurately modelled for both short and long channel devices. Complex degradation mechanisms and kinetics can be well explained by our model. Our results show that device lifetime can be underestimated by one decade without considering interaction

    Solvent-Free Synthesis of Quaternary Oxazolidine-2-thione β3-Amino Ester Analogs

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    A solvent-free organocatalyzed intermolecular cyclization reaction starting from β-substituted γ-hydroxy-α,β-unsaturated esters and aryl isothiocyanates proceeds via an aza-Michael addition to provide previously unknown quaternary oxazolidine-2-thione β3 amino ester analogs. A panel of diversely-substituted esters was investigated, including β,γ-disubstituted examples which provided the target molecules with very high cis diastereoselectivity

    Comparability of surrogate and self-reported information on melanoma risk factors.

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    Surrogate reports by patients about their relatives, and vice versa, are potentially of great use in studies of the genetic and environmental causes of the familial aggregation of cancer. To assess the quality of such information in a family study of melanoma aetiology in Queensland, Australia, the authors compared surrogate reports with self-reports of standard melanoma risk factors obtained by mailed self-administered questionnaire. There was moderate agreement between surrogate reports provided by the cases and relatives' self-reports for questions on ability to tan (polychoric correlation coefficient (pc) = 0.60), skin colour (pc = 0.57), average propensity to burn (pc = 0.56), and hair colour at age 21 (kappa coefficient = 0.55), although relatives in the extreme risk factor categories were misclassified by surrogates at least half of the time. Agreement was lower for questions on degree of moliness (pc = 0.45), tendency to acute sunburn (pc = 0.42), and number of episodes of painful sunburn (pc = 0.23). The quality of relatives' surrogate reports about cases was similar to that of cases' surrogate reports about relatives. Cases who reported a family history of melanoma provided better surrogate information than did cases who indicated no family history, and female cases provided better surrogate reports than did males. Cases were better able to report for their parents and children than for their siblings. The authors conclude that when the use of surrogate reports of melanoma risk factors is unavoidable, results should be interpreted cautiously in the light of potentially high rates of misclassification. In particular, surrogate reports appear to be a comparatively poor measure of self-assessment of number of moles, the strongest known phenotypic indicator of melanoma risk, and may bias comparisons between families with and without a history of melanoma

    The Inner Rings of Beta Pictoris

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    We present Keck images of the dust disk around Beta Pictoris at 17.9 microns that reveal new structure in its morphology. Within 1" (19 AU) of the star, the long axis of the dust emission is rotated by more than 10 degrees with respect to that of the overall disk. This angular offset is more pronounced than the warp detected at 3.5" by HST, and in the opposite direction. By contrast, the long axis of the emission contours at ~ 1.5" from the star is aligned with the HST warp. Emission peaks between 1.5" and 4" from the star hint at the presence of rings similar to those observed in the outer disk at ~ 25" with HST/STIS. A deconvolved image strongly suggests that the newly detected features arise from a system of four non-coplanar rings. Bayesian estimates based on the primary image lead to ring radii of 14+/-1 AU, 28+/-3 AU, 52+/-2 AU and 82+/-2 AU, with orbital inclinations that alternate in orientation relative to the overall disk and decrease in magnitude with increasing radius. We believe these new results make a strong case for the existence of a nascent planetary system around Beta Pic.Comment: 5 pages, 2 figures, PDF format. Published in ApJL, December 20,200
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