2,060 research outputs found

    3-D Seismic Response Analysis for Zipingpu Concrete Faced Rockfill Dam

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    Zipingpu concrete faced rockfill dam is located at upstream of Min River in Yangtze River drainage basin. It is the main body of Zipingpu hinge who governs irrigating, water supplying, generating electricity, preventing flood and so on. The dam is 156 meters high and 663.8 meters long. And the normal water level is 148 meters high. Investigations indicate the peak ground accelerations is 0.26g and the characteristic period of the ground is 0.17 second. Three-dimensional seismic response analysis was carried out for this dam. Improved equivalent visco-elastic model was adopted in FEM analysis. And the method of equal node force was used in residual deformation analysis. In the analysis, the foundation was supposed to be a rigid body. Time histories of the response accelerations, stresses and displacements as well as their distributions were obtained. The residual deformation induced by the input earthquake excitation was also evaluated. The analysis is of much benefit to understanding of the performance of the dam to a strong earthquake

    Static and Dynamic Response Analysis of a High Rock-Fill Dam with a Clay Core

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    Stress strain analysis based on Biot’s consolidation theory is performed for Nuozhadu dam, which is a high rock-fill clay-core dam located in the Langcangjiang River in Yunnan province, China. Attention is mainly focused on arching effect and possibility of hydraulic fracturing of the core. Equivalent linear approach is employed to evaluate the seismic response of the dam under design earthquakes, and two empirical formulas relating residual shear and volumetric strain to cyclic stress and strain history are proposed to evaluate the permanent deformation. It is found that: 1) the modulus ratio of the clay in the core to rockfills around is the main factor controlling the severity of arching effect, 2) hydraulic fracture would not occur according to the criterion of effective stress, and 3) the permanent deformation that is likely to occur is acceptable under the condition of design earthquakes

    Metric-based Few-shot Classification in Remote Sensing Image

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    Target recognition based on deep learning relies on a large quantity of samples, but in some specific remote sensing scenes, the samples are very rare. Currently, few-shot learning can obtain high-performance target classification models using only a few samples, but most researches are based on the natural scene. Therefore, this paper proposes a metric-based few-shot classification technology in remote sensing. First, we constructed a dataset (RSD-FSC) for few-shot classification in remote sensing, which contained 21 classes typical target sample slices of remote sensing images. Second, based on metric learning, a k-nearest neighbor classification network is proposed, to find multiple training samples similar to the testing target, and then the similarity between the testing target and multiple similar samples is calculated to classify the testing target. Finally, the 5-way 1-shot, 5-way 5-shot and 5-way 10-shot experiments are conducted to improve the generalization of the model on few-shot classification tasks. The experimental results show that for the newly emerged classes few-shot samples, when the number of training samples is 1, 5 and 10, the average accuracy of target recognition can reach 59.134%, 82.553% and 87.796%, respectively. It demonstrates that our proposed method can resolve fewshot classification in remote sensing image and perform better than other few-shot classification methods

    Flavor Violating Higgs Couplings in Minimal Flavor Violation

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    Motivated by the rencent LHC data on the lepton-flavor violating (LFV) decays h→ℓ1ℓ2h\to \ell_1 \ell_2 and Bs,d→ℓ1ℓ2B_{s,d}\to \ell_1 \ell_2, we study the Higgs-mediated flavor-changing neutral current (FCNC) interactions in the effective field theory (EFT) approach without and with the minimal flavor violation (MFV) hypothesis, and concentrate on the later. After considering the BB and KK physics data, the various LFV processes, and the LHC Higgs data, severe constraints on the Higgs FCNC couplings are derived, which are dominated by the LHC Higgs data, the Bs−BˉsB_s - \bar B_s mixing, and the μ→eγ\mu \to e \gamma decay. In the general case and the MFV framework, allowed ranges of various observables are obtained, such as B(Bs→ℓ1ℓ2)\mathcal B (B_s\to \ell_1 \ell_2), B(h→ℓ1ℓ2)\mathcal B (h\to \ell_1 \ell_2), B(h→q1q2)\mathcal B (h\to q_1 q_2), and the branching ratio of μ→e\mu \to e conversion in Al. Future prospects of searching for the Higgs FCNC interactions at the low-energy experiments and the LHC are discussed.Comment: 26 pages, 5 figures, minor errors corrected, figures slightly changed, comments and references adde
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