180 research outputs found

    Few-shot Text Classification with Dual Contrastive Consistency

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    In this paper, we explore how to utilize pre-trained language model to perform few-shot text classification where only a few annotated examples are given for each class. Since using traditional cross-entropy loss to fine-tune language model under this scenario causes serious overfitting and leads to sub-optimal generalization of model, we adopt supervised contrastive learning on few labeled data and consistency-regularization on vast unlabeled data. Moreover, we propose a novel contrastive consistency to further boost model performance and refine sentence representation. After conducting extensive experiments on four datasets, we demonstrate that our model (FTCC) can outperform state-of-the-art methods and has better robustness.Comment: 8 pages, 2 figures, under revie

    USING COMPUTED TOMOGRAPHY SCANNING TECHNOLOGY TO EXTRACT VIRTUAL WOOD CORES, DERIVE WOOD DENSITY RADIAL PATTERNS, AND TEST HYPOTHESIS ABOUT DIRECTION, CORE SIZE, AND YEAR OF GROWTH

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    Computed tomography (CT) scanning technology was used to collect millions of three-dimensional data called “CT numbers”, on two sets of white spruce (Picea glauca [Moench] Voss) wood disks. Data collected were then converted to wood density estimates using a calibration equation for wood. Virtual wood cores with three different sizes (i.e., 1 voxel – the smallest volumetric unit on which a CT number was computed, 5 mm and 12 mm in diameter) were extracted from pith to bark and in four orthogonal directions. This made it possible to test the effects of core direction and size on the wood density estimates obtained. The average values as well as the radial patterns of wood density as estimated from CT scanning data were found to be typical of the values and patterns reported for the white spruce tree species in the literature, especially in relation to cambial age as the experimental trees were of different ages. In conclusion, wood science application of CT scanning technology allows extracting data subsets in 3D to perform density estimation, pattern analysis and hypothesis testing, and the results are valuable complements to those obtained with other technologies such as X-ray densitometry

    Clinical Observation of Erlotinib in the Treatment of Advanced Non-small Cell Lung Cancer: A Report of 92 Eases

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    Background and objective Erlotinib, a selective inhibitor of epidermal growth factor receptor tyrosine kinase, has been approved effective in local advanced or metastatic non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the efficacy and safety of erlotinib for the treatment of advanced NSCLC. Methods Ninety-two patients with advanced NSCLC who had failed or not tolerated or refused chemotherapy received 150 mg oral doses of erlotinib once daily until the disease progression or intolerable toxicity. Results Among the 92 NSCLC patients, 2 patient got complete response (2.2%), 22 partial response (23.9%), 48 stable disease (52.2%) and 20 progressive disease (21.7%). The overall response rate and the disease controlled rate of erlotinib was 26.1% (24/92) and 78.3% (72/92), respectively. The response rate of erlotinib were significantly higher in rash and ECOG 0-1 than no rash and ECOG ≄ 2. The disease controlled rate of erlotinib was significantly higher in female and non-smokers than male and smokers (P < 0.05). The response rate of erlotinib did not show significant differences within pathological type or previous treatment. The most common side effects were rash and diarrhea with 84.8% and 31.5%, respectively, but usually were mild. Conclusion Erlotinib is effective and safe in the treatment of advanced NSCLC patients

    Synchrotron X-ray microtomography and multifractal analysis for the characterization of pore structure and distribution in softwood pellet biochar

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    Biochar pores in the micrometer range (1–100 ”m) derive from cellular structures of the plant biomass subjected to pyrolysis or can be the result of mechanical processing, such as pelleting. In this study, synchrotron X-ray microtomography was used to investigate the internal pore structure of softwood pellet biochar produced by slow pyrolysis at 550 and 700 °C. The microtomographic data sets consisted of 2025 images of 2560 × 2560 voxels with a voxel side length of 0.87 ”m. The three-dimensional reconstructions revealed that pelleting and pyrolysis significantly altered the pore structures of the wood feedstock, creating a network of connected pores between fragments that resembled the wood morphology. While higher pyrolysis temperature increased the specific surface area (as determined by BET nitrogen adsorption), it did not affect the total observed porosity. Multifractal analysis was applied to assess the characteristics of the frequency distribution of pores along each of the three dimensions of reconstructed images of five softwood pellet biochar samples. The resulting singularity and RĂ©nyi spectra (generalized dimensions) indicated that the distribution of porosity had monofractal scaling behavior, was homogeneous within the analyzed volumes and consistent between replicate samples. Moreover, the pore distributions were isotropic (direction-independent), which is in strong contrast with the anisotropic pore structure of wood. As pores at the scale analyzed in this study are relevant, for example, for the supply of plant accessible water and habitable space for microorganisms, our findings combined with the ability to reproduce biochar with such pore distribution offer substantial advantages in various biochar applications.</p

    Experimental Study of Cohesive Embankment Dam Breach Formation due to Overtopping

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    The recurrent floods in recent decades have imposed a challenge of embankment dam breaching, which needs great attention through improved design methods that are based on risk approach, the evacuation plans for people at risk, etc. In this study, based on the small-scale model tests a series of experiments were conducted to determine the breaching process of cohesive embankment dam using a simplified physical based breach model due to overtopping; the breach process observed during tests in the laboratory and the results from analyzed parameters are described. Five dam models, three of which were constructed with homogenous clay soil while two were sandy-clay mixture tested. The heights of the embankments dam were 0.45 m, and the widths at the crest were 0.20 m. The data from these examinations indicated that headcut erosion played an important role in the process of breach development. Initiation of erosion, flow shear erosion, sidewall bottom erosion, and distinct soil mechanical slope mass failure from the headcut vertically and laterally were all observed during these tests. In this physical based experimental model, the initial scouring position calculated by applying a hydraulic method, the broad crested weir formula used for breaching flow discharge and flow velocity computed based on breach flow discharge. The stability of the side slope failures was estimated by comparing the resisting and deriving force. Further, using data from laboratory experiments, the calculated peak breach discharge, breach characteristics times, breach widths, and breach flow velocity generally agreed well with the measured data and also the knowledge acquired from observed breach process at several stages. Finally, the accuracy of model was checked by root-mean-square-error
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