90 research outputs found

    Fuzzy Analytic Hierarchy Process Evaluation Method in Assessing Corrosion Damage of Reinforced Concrete Bridges

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    Effective method used to deal with the corrosion damage condition of any concrete bridge superstructure will help decision makers of bridge management agencies to better choose repair material, and optimize repair method. Simplified corrosion index (SCI) is a very useful and simple index to characterize the actual corrosion damage condition of a reinforced concrete bridge superstructure. In this paper, SCI is calculated by combining the Corrosion Damage Index (CDI), Environment Change Factor (ECF) and Material Vulnerability Factor (MVF). The Analytic Hierarchy Process (AHP) method is applied to decide the weight factors of CDI, ECF and MVF. The Fuzzy-AHP evaluation method is used in this study to deal with the fuzzy problem of differentiating the different levels of corrosion indicators and to determine the appropriate weight factors. The asymmetric nearness degree method is applied to re-analyze the evaluation vector from Fuzzy-AHP method to calculate the corrosion damage level based on all corrosion indicators. A numerical example was presented to demonstrate the procedure and the benefits of the AHP method, and the proposed Fuzzy-AHP approach, along with the asymmetric nearness degree method, in dealing with the fuzzy nature of SCI calculation problem

    On the performance of an integrated communication and localization system: an analytical framework

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    Quantifying the performance bound of an integrated localization and communication (ILAC) system and the trade-off between communication and localization performance is critical. In this letter, we consider an ILAC system that can perform communication and localization via time-domain or frequency-domain resource allocation. We develop an analytical framework to derive the closed-form expression of the capacity loss versus localization Cramer-Rao lower bound (CRB) loss via time-domain and frequency-domain resource allocation. Simulation results validate the analytical model and demonstrate that frequency-domain resource allocation is preferable in scenarios with a smaller number of antennas at the next generation nodeB (gNB) and a larger distance between user equipment (UE) and gNB, while time-domain resource allocation is preferable in scenarios with a larger number of antennas and smaller distance between UE and the gNB.Comment: 5 pages, 3 figure

    Quasinormal modes of a black hole in the deformed Ho\v{r}ava-Lifshitz gravity

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    We study the quasinormal modes of the massless scalar perturbation in the background of a deformed black hole in the Ho\v{r}ava-Lifshitz gravity with coupling constant λ=1\lambda=1. Our results show that the quasinormal frequencies depend on the parameter in the Ho\v{r}ava-Lifshitz gravity and the behavior of the quasinormal modes is different from those in the Reissner-Norstr\"{om} and Einstein-Born-Infeld black hole spacetimes. The absolute value of imaginary parts is smaller and the scalar perturbations decay more slowly in the deformed Ho\v{r}ava-Lifshitz black hole spacetime. This information can help us understand more about the Ho\v{r}ava-Lifshitz gravity.Comment: 9 pages, 3 figures and 4 table

    Ooceraea hainingensis sp. nov.: A new Chinese Ooceraea (Hymenoptera, Formicidae, Dorylinae) species with a dealate queen, closely allied to the queenless clonal raider ant O. biroi

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    The clonal raider ant, Ooceraea biroi, is a queenless species that reproduces asexually, and these traits make it an attractive model system for laboratory research. However, it is unclear where on the ant phylogeny these traits evolved, partly because few closely related species have been described and studied. Here, we describe a new raider ant species, Ooceraea hainingensis sp. nov., from Zhejiang, China. This species is closely related to O. biroi but can be distinguished by the following features: 1) workers of O. hainingensis sp. nov. have an obvious promesonotal suture and a metanotal groove, whereas these characters are ambiguous in O. biroi; and 2) the subpetiolar process of O. hainingensis is prominent and anteroventrally directed like a thumb with sublinear posteroventral margin, while in O. biroi, it is anteroventrally directed but slightly backward-bent. Molecular phylogenetic analyses confirm that O. hainingensis is genetically distinct from O. biroi. Importantly, unlike O. biroi, O. hainingensis has a queen caste with wings and well-developed eyes. This suggests that the loss of the queen caste and transition to asexual reproduction by workers is specific to O. biroi and occurred after that species diverged from closely related congeneric species

    Greybody factor for a scalar field coupling to Einstein's tensor

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    We study the greybody factor and Hawking radiation for a scalar field coupling to Einstein's tensor in the background of Reissner-Nordstr\"om black hole in the low-energy approximation. We find that the presence of the coupling terms modifies the standard results in the greybody factor and Hawking radiation. Our results show that both the absorption probability and Hawking radiation increase with the coupling constant. Moreover, we also find that for the stronger coupling, the charge of black hole enhances the absorption probability and Hawking radiation of the scalar field, which is different from those of ones without coupling to Einstein's tensor in the black hole spacetime.Comment: 14 pages, 6 figures, Accepted by PL

    Long noncoding RNA NEAT1 (nuclear paraspeckle assembly transcript 1) is critical for phenotypic switching of vascular smooth muscle cells

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    In response to vascular injury, vascular smooth muscle cells (VSMCs) may switch from a contractile to a proliferative phenotype thereby contributing to neointima formation. Previous studies showed that the long noncoding RNA (lncRNA) NEAT1 is critical for paraspeckle formation and tumorigenesis by promoting cell proliferation and migration. However, the role of NEAT1 in VSMC phenotypic modulation is unknown. Herein we showed that NEAT1 expression was induced in VSMCs during phenotypic switching in vivo and in vitro. Silencing NEAT1 in VSMCs resulted in enhanced expression of SM-specific genes while attenuating VSMC proliferation and migration. Conversely, overexpression of NEAT1 in VSMCs had opposite effects. These in vitro findings were further supported by in vivo studies in which NEAT1 knockout mice exhibited significantly decreased neointima formation following vascular injury, due to attenuated VSMC proliferation. Mechanistic studies demonstrated that NEAT1 sequesters the key chromatin modifier WDR5 (WD Repeat Domain 5) from SM-specific gene loci, thereby initiating an epigenetic "off" state, resulting in down-regulation of SM-specific gene expression. Taken together, we demonstrated an unexpected role of the lncRNA NEAT1 in regulating phenotypic switching by repressing SM-contractile gene expression through an epigenetic regulatory mechanism. Our data suggest that NEAT1 is a therapeutic target for treating occlusive vascular diseases

    Extension of non-minimal derivative coupling theory and Hawking radiation in black-hole spacetime

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    We study the greybody factor and Hawking radiation with a non-minimal derivative coupling between the scalar field and the curvature in the background of the slowly rotating Kerr-Newman black hole. Our results show that both the absorption probability and luminosity of Hawking radiation of the scalar field increase with the coupling. Moreover, we also find that for the weak coupling η<ηc\eta<\eta_c, the absorption probability and luminosity of Hawking radiation decrease when the black hole's Hawking temperature decreases; while for stronger coupling η>ηc\eta>\eta_c, the absorption probability and luminosity of Hawking radiation increase on the contrary when the black hole's Hawking temperature decreases. This feature is similar to the Hawking radiation in a dd-dimensional static spherically-symmetric black hole surrounded by quintessence \cite{chensong}.Comment: 17 pages, 6 figures, 1 table, Title changed, Appendix changed, accepted by JHE
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