4,694 research outputs found

    clcNet: Improving the Efficiency of Convolutional Neural Network using Channel Local Convolutions

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    Depthwise convolution and grouped convolution has been successfully applied to improve the efficiency of convolutional neural network (CNN). We suggest that these models can be considered as special cases of a generalized convolution operation, named channel local convolution(CLC), where an output channel is computed using a subset of the input channels. This definition entails computation dependency relations between input and output channels, which can be represented by a channel dependency graph(CDG). By modifying the CDG of grouped convolution, a new CLC kernel named interlaced grouped convolution (IGC) is created. Stacking IGC and GC kernels results in a convolution block (named CLC Block) for approximating regular convolution. By resorting to the CDG as an analysis tool, we derive the rule for setting the meta-parameters of IGC and GC and the framework for minimizing the computational cost. A new CNN model named clcNet is then constructed using CLC blocks, which shows significantly higher computational efficiency and fewer parameters compared to state-of-the-art networks, when being tested using the ImageNet-1K dataset. Source code is available at https://github.com/dqzhang17/clcnet.torch

    Simple non-Abelian extensions of the standard model gauge group and the diboson excesses at the LHC

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    The ATLAS collaboration reported excesses at around 2 TeV in the di-boson production decaying into hadronic final states. We consider the possibility of explaining the excesses with extra gauge bosons in two simple non-Abelian extensions of the Standard Model. One is the so-called G(221)G(221) models with a symmetry structure of SU(2)1SU(2)2U(1)XSU(2)_1\otimes SU(2)_2\otimes U(1)_X and the other is the G(331)G(331) models with an extended symmetry of SU(3)CSU(3)LU(1)XSU(3)_C\otimes SU(3)_L\otimes U(1)_X. The WW' and ZZ' bosons emerge after the electroweak symmetry is spontaneously broken. Two patterns of symmetry breaking in the G(221)G(221) models are considered in this work: one is SU(2)LSU(2)2U(1)XSU(2)LU(1)YSU(2)_L\otimes SU(2)_2 \otimes U(1)_X \to SU(2)_L\otimes U(1)_Y, the other is SU(2)1SU(2)2U(1)YSU(2)LU(1)YSU(2)_1\otimes SU(2)_2 \otimes U(1)_Y \to SU(2)_L\otimes U(1)_Y. The symmetry breaking of the G(331)G(331) model is SU(3)LU(1)XSU(2)LU(1)YSU(3)_L\otimes U(1)_X \to SU(2)_L \otimes U(1)_Y. We perform a global analysis of WW^\prime and ZZ^\prime phenomenology in ten new physics models, including all the channels of W/ZW^\prime/Z^\prime decay. Our study shows that the leptonic mode and the dijet mode of W/ZW^\prime/Z^\prime decays impose a very stringent bound on the parameter space in several new physics models. Such tight bounds provide a useful guide for building new physics models to address on the diboson anomalies. We also note that the Left-Right and Lepton-Phobic models can explain the 3.4σ3.4\sigma WZWZ excess if the 2.6σ2.6\sigma deviation in the W+WW^+W^- pair around 2~TeV were confirmed to be a fluctuation of the SM backgrounds.Comment: Publish version; title changed as suggested by journal Edito

    Resolving the Degeneracy in Single Higgs Production with Higgs Pair Production

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    The Higgs boson production can be affected by several anomalous couplings, e.g. ctc_t and cgc_g anomalous couplings. Precise measurement of gghgg\to h production yields two degenerate parameter spaces of ctc_t and cgc_g; one parameter space exhibits the SM limit while the other does not. Such a degeneracy could be resolved by Higgs boson pair production. In this work we adapt the strategy suggested by the ATLAS collaboration to explore the potential of distinguishing the degeneracy at the 14 TeV LHC. If the ctc_t anomalous coupling is induced only by the operator HHQˉLH~tRH^\dag H \bar Q_L \tilde{H} t_R, then the non-SM-like band could be excluded with an integrated luminosity of 235 fb1\sim 235~{\rm fb}^{-1}. Making use of the fact that the Higgs boson pair is mainly produced through an ss-wave scattering, we propose an analytical function to describe the fraction of signal events surviving a series of experimental cuts for a given invariant mass of Higgs boson pair. The function is model independent and can be applied to estimate the discovery potential of various NP models

    Context-Aware Single-Shot Detector

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    SSD is one of the state-of-the-art object detection algorithms, and it combines high detection accuracy with real-time speed. However, it is widely recognized that SSD is less accurate in detecting small objects compared to large objects, because it ignores the context from outside the proposal boxes. In this paper, we present CSSD--a shorthand for context-aware single-shot multibox object detector. CSSD is built on top of SSD, with additional layers modeling multi-scale contexts. We describe two variants of CSSD, which differ in their context layers, using dilated convolution layers (DiCSSD) and deconvolution layers (DeCSSD) respectively. The experimental results show that the multi-scale context modeling significantly improves the detection accuracy. In addition, we study the relationship between effective receptive fields (ERFs) and the theoretical receptive fields (TRFs), particularly on a VGGNet. The empirical results further strengthen our conclusion that SSD coupled with context layers achieves better detection results especially for small objects (+3.2%AP@0.5+3.2\% {\rm AP}_{@0.5} on MS-COCO compared to the newest SSD), while maintaining comparable runtime performance

    Overexpression of an isoform of AML1 in acute leukemia and its potential role in leukemogenesis

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    AML1/RUNX1 is a critical transcription factor in hematopoietic cell differentiation and proliferation. From the _AML1_ gene, at least three isoforms, _AML1a_, _AML1b_ and _AML1c_, are produced through alternative splicing. AML1a interferes with the function of AML1b/1c, which are often called AML1. In the current study, we found a higher expression level of _AML1a_ in ALL patients in comparison to the controls. Additionally, AML1a represses transcription from promotor of macrophage-colony simulating factor receptor (M-CSFR) mediated by AML1b, indicating that AML1a antagonized the effect of AML1b. In order to investigate the role of _AML1a_ in hematopoiesis and leukemogenesis _in vivo_, bone marrow mononuclear cells (BMMNCs) from mice were transduced with AML1a and transplanted into lethally irradiated mice, which develop lymphoblastic leukemia after transplantation. Taken together, these results indicate that overexpression of AML1a may be an important contributing factor to leukemogenesis

    Rapid analysis of the bioactive components in Saxifraga stolonifera, an edible and medicinal herb with anti-tumor effects, by HPLC-DAD, ESI/MSn

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    Saxifraga stolonifera is an edible and herbaceous plant, which has been demonstrated to have anti-tumor effects in vivo and in vitro. The aim of this paper is to determine the main bioactive components inS. stolonifera, and their distribution in different parts of S. stolonifera and in S. stolonifera that was cultivated in different places in China using a high-performance liquid chromatography-diode array detector and electrospray ionization/ion trap mass spectrometry (HPLC-DAD-ESI/MSn). Four main components were identified and three were quantified. The contents of gallic acid, protocatechuic acid and bergenin had significant differences not only between the roots and stems-leaves of the plant, but also among different cultivated varieties of S. stolonifera. The experiment showed that the method used here exhibited good repeatability and recovery. Therefore, the results provide reliable data for research and development in the future on the level and distribution of the three bioactive components of S. stolonifera

    Continuous variable entanglement measurement without phase locking

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    A new simple entanglement measurement method is proposed for the bright EPR beams generated from a non-degenerate optical parametric amplifier operating at deamplification. Due to the output signal and idler modes are frequency degenerate and in phase, the needed phase shift of interference for the measurement of the correlated phase quadratures and anti-correlated amplitude quadratures can be accomplished by a quarter-wave plate and a half wave plate without separating the signal and idler beam. Therefore, phase locking and local oscillators are avoided.Comment: 8 pages,3 figure

    Dark Energy and Fate of the Universe

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    We explore the ultimate fate of the Universe by using a divergence-free parametrization for dark energy w(z)=w0+wa(ln(2+z)1+zln2)w(z)=w_0+w_a({\ln (2+z)\over 1+z}-\ln2). Unlike the CPL parametrization, this parametrization has well behaved, bounded behavior for both high redshifts and negative redshifts, and thus can genuinely cover many theoretical dark energy models. After constraining the parameter space of this parametrization by using the current cosmological observations, we find that, at the 95.4% confidence level, our Universe can still exist at least 16.7 Gyr before it ends in a big rip. Moreover, for the phantom energy dominated Universe, we find that a gravitationally bound system will be destroyed at a time tP21+3w(1)/[6π1+w(1)]t \simeq P\sqrt{2|1+3w(-1)|}/[6\pi |1+w(-1)|], where PP is the period of a circular orbit around this system, before the big rip.Comment: 5 pages, 3 figures; typos corrected, publication version, Sci China-Phys Mech Astron, doi: 10.1007/s11433-012-4748-
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