4,263 research outputs found

    Semi-Supervised Learning for Neural Machine Translation

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    While end-to-end neural machine translation (NMT) has made remarkable progress recently, NMT systems only rely on parallel corpora for parameter estimation. Since parallel corpora are usually limited in quantity, quality, and coverage, especially for low-resource languages, it is appealing to exploit monolingual corpora to improve NMT. We propose a semi-supervised approach for training NMT models on the concatenation of labeled (parallel corpora) and unlabeled (monolingual corpora) data. The central idea is to reconstruct the monolingual corpora using an autoencoder, in which the source-to-target and target-to-source translation models serve as the encoder and decoder, respectively. Our approach can not only exploit the monolingual corpora of the target language, but also of the source language. Experiments on the Chinese-English dataset show that our approach achieves significant improvements over state-of-the-art SMT and NMT systems.Comment: Corrected a typ

    Effect of BFRP Grid on Crack Propagation of Reinforced Concrete Beam with Thick-Cover Concrete

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    For the purpose of solving the problem of large crack width in concrete beam with thick cover, BFRP grid is added to the concrete cover to control the crack development and to improve the distribution status of cracks. In this paper, the bending tests under four-point loading are adopted to investigate cracking properties of reinforced concrete beams with thick cover, in which BFRP grid is added. During test cracking load, crack width and the number of crack were recorded, which will be analysed later. Test results show that crack development of reinforced concrete beam with thick cover can be effectively controlled, and the number of cracks was increased appearing tiny and dense cracks in structure, meanwhile maximum crack width was decreased, which can meet the requirements of engineering for crack control. In addition, BFRP grid has no effect on the cracking load of the structure and can slightly increase the ultimate bearing capacity

    Unifying ultrafast demagnetization and intrinsic Gilbert damping in Co/Ni bilayers with electronic relaxation near the Fermi surface

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    The ability to controllably manipulate the laser-induced ultrafast magnetic dynamics is a prerequisite for future high speed spintronic devices. The optimization of devices requires the controllability of the ultrafast demagnetization time, , and intrinsic Gilbert damping, . In previous attempts to establish the relationship between and , the rare-earth doping of a permalloy film with two different demagnetization mechanism is not a suitable candidate. Here, we choose Co/Ni bilayers to investigate the relations between and by means of time-resolved magneto-optical Kerr effect (TRMOKE) via adjusting the thickness of the Ni layers, and obtain an approximately proportional relation between these two parameters. The remarkable agreement between TRMOKE experiment and the prediction of breathing Fermi-surface model confirms that a large Elliott-Yafet spin-mixing parameter is relevant to the strong spin-orbital coupling at the Co/Ni interface. More importantly, a proportional relation between and in such metallic films or heterostructures with electronic relaxation near Fermi surface suggests the local spin-flip scattering domains the mechanism of ultrafast demagnetization, otherwise the spin-current mechanism domains. It is an effective method to distinguish the dominant contributions to ultrafast magnetic quenching in metallic heterostructures by investigating both the ultrafast demagnetization time and Gilbert damping simultaneously. Our work can open a novel avenue to manipulate the magnitude and efficiency of Terahertz emission in metallic heterostructures such as the perpendicular magnetic anisotropic Ta/Pt/Co/Ni/Pt/Ta multilayers, and then it has an immediate implication of the design of high frequency spintronic devices

    Calculation analysis of yaw bearings with a hardened raceway

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    The yaw bearing is a key support structure of wind turbines and is often exposed to substantial complex loads that cause damage and fatigue failure. Raceway surfaces accommodate high contact stress and require a hardening treatment. The hardened depth has a great influence on both the carrying capacity and fatigue life. We establish a whole finite element model of a yaw bearing and use non-linear springs instead of a ball to obtain the maximum contact load. The results of a strain gauge experiment and an empirical formula are compared to verify the spring model results. A local finite element model of a ball and raceway with different hardened depths is established to analyse the stress distribution and fatigue life. The raceway is divided into a hardened layer, transition layer, and core layer. An indentation experiment verifies the raceway model with different layers. The stress results are compared with Hertz contact theory, and the fatigue life results are compared with yaw bearing fatigue life theory. The influence of different hardened depths on the stress and lifetime of yaw bearings is analysed

    Cloning and selection of reference genes for gene expression studies in Ananas comosus

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    Full length mRNA sequences of Ac-β-actin and Ac-gapdh, and partial mRNA sequences of Ac-18SrRNA and Ac-ubiquitin were cloned from pineapple in this study. The four genes were tested as housekeeping genes in three experimental sets. GeNorm and NormFinder analysis revealed that β-actin was the most appropriate reference gene for qPCR analysis of callus under induction conditions and in different tissue types, meanwhile, 18SrRNA was the most stable reference gene during organ development. Gapdh was the most unstable gene in all tested experimental sets. Transcript level analysis result of AcSERK1 in stressed callus normalized by β-actin and 18SrRNA further confirmed that reference genes selected in this study were suitable for transcript level analysis of pineapple. The expression pattern of AcSERK1 during somatic embryogenesis normalized by β-actin coincided with the cytological features of calluses during somatic embryogenesis. These results will enable more accurate and reliable normalization of qPCR results for transcription analysis in pineapple. Keywords: Reference genes, qPCR, pineapple, geNorm, NormFinder African Journal of Biotechnology Vol. 11(29), pp. 7424-7433, 10 April, 201

    Insights into long noncoding RNAs of naked mole rat (Heterocephalus glaber) and their potential association with cancer resistance

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    Additional file 4: Table S3. Differential expressed lncRNAs identified in naked mole rat (Heterocephalus glaber) genome
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