2,919 research outputs found

    Deep Laplacian Pyramid Networks for Fast and Accurate Super-Resolution

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    Convolutional neural networks have recently demonstrated high-quality reconstruction for single-image super-resolution. In this paper, we propose the Laplacian Pyramid Super-Resolution Network (LapSRN) to progressively reconstruct the sub-band residuals of high-resolution images. At each pyramid level, our model takes coarse-resolution feature maps as input, predicts the high-frequency residuals, and uses transposed convolutions for upsampling to the finer level. Our method does not require the bicubic interpolation as the pre-processing step and thus dramatically reduces the computational complexity. We train the proposed LapSRN with deep supervision using a robust Charbonnier loss function and achieve high-quality reconstruction. Furthermore, our network generates multi-scale predictions in one feed-forward pass through the progressive reconstruction, thereby facilitates resource-aware applications. Extensive quantitative and qualitative evaluations on benchmark datasets show that the proposed algorithm performs favorably against the state-of-the-art methods in terms of speed and accuracy.Comment: This work is accepted in CVPR 2017. The code and datasets are available on http://vllab.ucmerced.edu/wlai24/LapSRN

    Burn-In Aging Behavior and Analytical Modeling of Wavelength-Division Multiplexing Semiconductor Lasers: Is the Swift Burn-In Feasible for Long-Term Reliability Assurance?

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    Effective and economical burn-in screening is important for technology development and manufacture of semiconductor lasers. We study the burn-in degradation behavior of wavelength-division multiplexing semiconductor lasers to determine the feasibility of short burn-in. The burn-in is characterized by the sublinear model and correlated with long-term reliability

    TeV Scale Phenomenology of e+eμ+μe^+e^- \to\mu^+ \mu^- Scattering in the Noncommutative Standard Model with Hybrid Gauge Transformation

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    The hybrid gauge transformation and its nontrivial phenomenological implications are investigated using the noncommutative gauge theory with the Seiberg-Witten map expanded scenario. Particularly, the e+eμ+μe^+e^- \to\mu^+ \mu^- process is studied with a generalized noncommutative standard model (NCSM) including massive neutrinos and neutrino-photon interaction. In this model, the hybrid gauge transformation in the lepton sector is naturally introduced through the requirement of gauge invariance of the seesaw neutrino mass term. It is shown that in the NCSM without hybrid gauge transformation the noncommutative correction to the scattering amplitude of the e+eμ+μe^+e^- \to\mu^+ \mu^- process appears only as a phase factor, predicting no new physical deviation in the cross section. However, when the hybrid feature is considered, the noncommutative effect appears in the single channel process. The cross section and angular distribution are analyzed in the laboratory frame including Earth's rotation. It is proposed that pair production of muons in the upcoming TeV International Linear Collider (ILC) can provide an ideal opportunity for exploring not only the NC space-time, but also the mathematical structure of the corresponding gauge theory.Comment: 22 pages, 8 figure

    Selenium derivatization of nucleic acids for crystallography

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    The high-resolution structure of the DNA (5′-GTGTACA-C-3′) with the selenium derivatization at the 2′-position of T2 was determined via MAD and SAD phasing. The selenium-derivatized structure (1.28 Å resolution) with the 2′-Se modification in the minor groove is isomorphorous to the native structure (2.0 Å). To directly compare with the conventional bromine derivatization, we incorporated bromine into the 5-postion of T4, determined the bromine-derivatized DNA structure at 1.5 Å resolution, and found that the local backbone torsion angles and solvent hydration patterns were altered in the structure with the Br incorporation in the major groove. Furthermore, while the native and Br-derivatized DNAs needed over a week to form reasonable-size crystals, we observed that the Se-derivatized DNAs grew crystals overnight with high-diffraction quality, suggesting that the Se derivatization facilitated the crystal formation. In addition, the Se-derivatized DNA sequences crystallized under a broader range of buffer conditions, and generally had a faster crystal growth rate. Our experimental results indicate that the selenium derivatization of DNAs may facilitate the determination of nucleic acid X-ray crystal structures in phasing and high-quality crystal growth. In addition, our results suggest that the Se derivatization can be an alternative to the conventional Br derivatization

    Selection and Mid-infrared Spectroscopy of Ultraluminous Star-Forming Galaxies at z~2

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    Starting from a sample of 24 \micron\ sources in the Extended Groth Strip, we use 3.6 to 8 \micron\ color criteria to select ultraluminous infrared galaxies (ULIRGs) at z2z\sim2. Spectroscopy from 20-38 \micron\ of 14 objects verifies their nature and gives their redshifts. Multi-wavelength data for these objects imply stellar masses >1011{>}10^{11} \Msun\ and star formation rates \ge410 \Msun yr1^{-1}. Four objects of this sample observed at 1.6 \micron\ (rest-frame visible) with {\it HST}/WFC3 show diverse morphologies, suggesting that multiple formation processes create ULIRGs. Four of the 14 objects show signs of active galactic nuclei, but the luminosity appears to be dominated by star formation in all cases.Comment: 33 pages, 13 figures, accepted by Ap
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