72 research outputs found
Hysteretic Behavior Simulation Based on Pyramid Neural Network:Principle, Network Architecture, Case Study and Explanation
An accurate and efficient simulation of the hysteretic behavior of materials
and components is essential for structural analysis. The surrogate model based
on neural networks shows significant potential in balancing efficiency and
accuracy. However, its serial information flow and prediction based on
single-level features adversely affect the network performance. Therefore, a
weighted stacked pyramid neural network architecture is proposed herein. This
network establishes a pyramid architecture by introducing multi-level shortcuts
to integrate features directly in the output module. In addition, a weighted
stacked strategy is proposed to enhance the conventional feature fusion method.
Subsequently, the redesigned architectures are compared with other commonly
used network architectures. Results show that the redesigned architectures
outperform the alternatives in 87.5% of cases. Meanwhile, the long and
short-term memory abilities of different basic network architectures are
analyzed through a specially designed experiment, which could provide valuable
suggestions for network selection.Comment: 41 pages, 14 figure
The contribution and FIP bias of three types of materials inside ICMEs associated with different flare intensities
The studies on the origination and generation mechanisms of ICME materials
are crucial for understanding the connection between CMEs and flares. The
materials inside ICMEs can be classified into three types, coming from corona
directly (corona-materials), heated by magnetic reconnection in corona
(heated-corona-materials), and generated by chromospheric evaporation
(chromospheric-evaporation-materials). Here, the contribution and First
Ionization Potential (FIP) bias of three types of materials inside ICMEs
associated with different flare intensities are analyzed and compared. We find
that the speeds and scales of near-Earth ICMEs both increase with flare
intensities. The proportions of heated-corona-materials are nearly constant
with flare intensities. The contributions of corona-materials
(chromospheric-evaporation-materials) are significantly decreased (increased)
with flare intensities. More than two-thirds of materials are
chromospheric-evaporation-materials for ICMEs associated with strong flares.
The FIP bias of corona-materials and heated-corona-materials is almost the
same. The FIP bias of chromospheric-evaporation-materials is significantly
higher than that of corona-materials and heated-corona-materials, and it is
increased with flare intensities. The above characteristics of FIP bias can be
explained reasonably by the origination and generation mechanisms of three
types of ICME materials. The present study demonstrates that the origination
and generation mechanisms of ICME materials are significantly influenced by
flare intensities. The reasons for the elevation of FIP bias, if ICMEs are
regarded as a whole, are that the FIP bias of
chromospheric-evaporation-materials is much higher, and the
chromospheric-evaporation-materials contributed significantly to the ICMEs
which associated with strong flares.Comment: 12 pages, 3 figures, accepted for publication in Ap
Two jasmonic acid carboxyl methyltransferases in Gossypium hirsutum involved in MeJA biosynthesis may contribute to plant defense
Jasmonic acid (JA) and methyl jasmonate (MeJA), the crucial plant hormones, can induce the emission of plant volatiles and regulate the behavioral responses of insect pests or their natural enemies. In this study, two jasmonic acid carboxyl methyltransferases (JMTs), GhJMT1 and GhJMT2, involved in MeJA biosynthesis in Gossypium. hirsutum were identified and further functionally confirmed. In vitro, recombinant GhJMT1 and GhJMT2 were both responsible for the conversion of JA to MeJA. Quantitative real-time PCR (qPCR) measurement indicated that GhJMT1 and GhJMT2 were obviously up-regulated in leaves and stems of G. hirsutum after being treated with MeJA. In gas chromatography-mass spectrometry (GC-MS) analysis, MeJA treatment significantly induced plant volatiles emission such as (E)-β-ocimene, (Z)-3-hexenyl acetate, linalool and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), which play vital roles in direct and indirect plant defenses. Moreover, antennae of parasitoid wasps Microplitis mediator showed electrophysiological responses to MeJA, β-ocimene, (Z)-3-hexenyl acetate and linalool at a dose dependent manner, while our previous research revealed that DMNT excites electrophysiological responses and behavioral tendencies. These findings provide a better understanding of MeJA biosynthesis and defense regulation in upland cotton, which lay a foundation to JA and MeJA employment in agricultural pest control
Polynomial Smooth Twin Support Vector Machines
Smoothing functions can transform the unsmooth twin support vector machines (TWSVM) into smooth ones, and thus better classification results can be obtained. It has been one of the key problems to seek a better smoothing function in this field for a long time. In this paper, a novel version for smooth TWSVM, termed polynomial smooth twin support vector machines (PSTWSVM), is proposed. In PSTWSVM, using the series expansion, a new class of polynomial smoothing is proposed, and then their important properties are discussed. It is shown that the approximation accuracy and smoothness rank of polynomial functions can be as high as required. Subsequently, the polynomial functions are adopted to convert the original constrained quadratic programming problems of TWSVM into unconstrained minimization problems, and then are solved by the well-known Newton-Armijo algorithm. The effectiveness of the proposed method is demonstrated via experiments on synthetic and real-word benchmark datasets
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