679 research outputs found
Determinants of Polarized Sales Distribution in E-market: C2C Mobile Phone Market Scenario of China
The factors influencing huge divisions of wealth in society are widely studied by researchers. However, with the rapid development of the Internet, whether polarization or equalization of market shares exists in e-market among sellers springing up online, and how e-commerce affects its formation is still unknown to us. With a seller sample retrieved from Taobao, our study examines the polarization phenomenon and explores the determinants of its formation in the context of online markets. The descriptive analysis suggests a polarized phenomenon exists in e-commerce. Then this study applies quantile regression approach to investigate the factors that influence the formation of polarization in C2C mobile phone market. The results indicate that, a polarized sales distribution is existed; reputation and negative ratio play more important roles, while the number of items has a lower influence gradually. The empirical results can help us find the reason of polarization in C2C e-market
Guest editorial: WWWJ special issue of the 21th international Conference on Web Information Systems Engineering (WISE 2020)
Delay-induced multiple stochastic resonances on scale-free neuronal networks
We study the effects of periodic subthreshold pacemaker activity and
time-delayed coupling on stochastic resonance over scale-free neuronal
networks. As the two extreme options, we introduce the pacemaker respectively
to the neuron with the highest degree and to one of the neurons with the lowest
degree within the network, but we also consider the case when all neurons are
exposed to the periodic forcing. In the absence of delay, we show that an
intermediate intensity of noise is able to optimally assist the pacemaker in
imposing its rhythm on the whole ensemble, irrespective to its placing, thus
providing evidences for stochastic resonance on the scale-free neuronal
networks. Interestingly thereby, if the forcing in form of a periodic pulse
train is introduced to all neurons forming the network, the stochastic
resonance decreases as compared to the case when only a single neuron is paced.
Moreover, we show that finite delays in coupling can significantly affect the
stochastic resonance on scale-free neuronal networks. In particular,
appropriately tuned delays can induce multiple stochastic resonances
independently of the placing of the pacemaker, but they can also altogether
destroy stochastic resonance. Delay-induced multiple stochastic resonances
manifest as well-expressed maxima of the correlation measure, appearing at
every multiple of the pacemaker period. We argue that fine-tuned delays and
locally active pacemakers are vital for assuring optimal conditions for
stochastic resonance on complex neuronal networks.Comment: 7 two-column pages, 5 figures; accepted for publication in Chao
Optimization problems for general simple population with n-impulsive harvest
AbstractIn this paper, n-impulsive harvest problems of general simple population are discussed by models with Dirac function. The optimal impulsive harvest policies to protect the renewable resource better are obtained under conditions of fixed quantity per impulsive harvest. Then, a concept of the sequence for Ϝ-optimal harvest moments for general simple population is presented which is beneficial to protect resource better and sustainable development. Finally, we apply the conclusions to some special models
Knockdown of LncRNA SBF2-AS1 Inhibited Gastric Cancer Tumorigenesis via the Wnt/LRP5 Signaling Pathway
This investigation aimed to uncover the impact of a long noncoding RNA, SET-binding factor 2 antisense RNA1 (SBF2-AS1) on the malignant progression of gastric cancer (GC) and to further explore its underlying mechanism. SBF2-AS1 expression was quantified by qRT-PCR in GC cell lines and GC tissues. In vitro loss-of-function studies of SBF2-AS1, accompanied by flow cytometry, CCK-8, and cell invasion tests, were applied to elucidate the impact of SBF2-AS1 on the tumor progression of GC cells. Finally, Western blotting and a luciferase assay were used to detect WNT/LRP5 signaling pathway activation. SBF2-AS1 was aberrantly expressed in GC cell lines (p<0.05) and GC tissues (p<0.05). Cell invasive and proliferative capabilities were inhibited via SBF2-AS1 knockdown, resulting in apoptosis of NCI-N87 and MKN74 cells. Additionally, online database analysis uncovered a positive correlation between SBF2-AS1 and the Wnt/LRP5 signaling pathway (p<0.05). SBF2-AS1 knockdown blocked the Wnt/LRP5 signaling pathway, whereas the effects of SBF2-AS1 knockdown on the malignant genotype of MKN74 as well as NCI-N87 cells were partially restored by triggering the Wnt/ LRP5 signaling pathway. High expression of SBF2-AS1 was found in GC, the malignant progression of which was repressed via SBF2-AS1 knockdown by inhibiting the Wnt/LRP5 signaling pathway
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