373 research outputs found

    Nonlinear Dynamic Analysis of Cracked Beam on Elastic Foundation Subjected to Moving Mass

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    This paper presents a finite element algorithm for nonlinear dynamic analysis of cracked beams on an elastic foundation subjected to moving mass. Quantity surveying with parameters of varied cracks, foundation and loads shows their influence levels on the nonlinear dynamic response of the beams. The findings of the paper are the basis for the analysis, evaluation, and diagnosis of damages of beam structures on the elastic foundation subjected to moving loads, in which the common defects of the beams such as cracks are considered in order to improve the system's operational efficiency in a wide range of engineering applications

    (g-2)_{e, mu} and decays e_b--> e_a\gamma in a SU(4)_L x U(1)_X model with inverse seesaw neutrinos

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    We will show that the 3-4-1 model with heavy right-handed neutrinos can explain the recent experimental data of (g-2)_{e, mu} anomalies of charged leptons and neutrino oscillations through the inverse seesaw mechanism. In addition, the model can predict large lepton flavor violating decay rates mu --> e gamma and tau --> mu gamma, e gamma up to the recent experimental sensitivitiesComment: 28 pages, 8 figure

    Superpixel-based segmentation of muscle fibers in multi-channel microscopy

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    Background Confetti fluorescence and other multi-color genetic labelling strategies are useful for observing stem cell regeneration and for other problems of cell lineage tracing. One difficulty of such strategies is segmenting the cell boundaries, which is a very different problem from segmenting color images from the real world. This paper addresses the difficulties and presents a superpixel-based framework for segmentation of regenerated muscle fibers in mice. Results We propose to integrate an edge detector into a superpixel algorithm and customize the method for multi-channel images. The enhanced superpixel method outperforms the original and another advanced superpixel algorithm in terms of both boundary recall and under-segmentation error. Our framework was applied to cross-section and lateral section images of regenerated muscle fibers from confetti-fluorescent mice. Compared with “ground-truth” segmentations, our framework yielded median Dice similarity coefficients of 0.92 and higher. Conclusion Our segmentation framework is flexible and provides very good segmentations of multi-color muscle fibers. We anticipate our methods will be useful for segmenting a variety of tissues in confetti fluorecent mice and in mice with similar multi-color labels.National University of Singapore (Duke-NUS SRP Phase 2 Research Block Grant)Singapore. National Research Foundation (CREATE programme)Singapore-MIT Alliance for Research and Technology (SMART

    Temperature-dependent photoluminescence of ZnO layers grown on 6H-SiC substrates

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    Temperature-dependent photoluminescence(PL) of ZnO layers grown on 6H-SiC substrates has been described. The PLspectra were dominated by free exciton (FX) emission throughout the whole temperature range, which reflects shallow nonradiative centers in high crystalline ZnO layers. The temperature-dependent exciton peak energy as well as intensity quenching due to overlapping of FX and D⁰X (donor-bound exciton) bands has been addressed with an inclusion of donor-bound exciton-like defects. The D⁰Xlinewidth of ∌8 meV exhibited the thermal activation energy of ∌16 meV, closely consistent with the exciton-defect binding energy. This particular bound-exciton peak suggests that it dissociates into a FX and a neutral-donor-bound-like defects pair complex with the increase of temperature.This work was supported in part by the Special Postdoctoral Research Fellowship Program, Photodynamics Research Center, The Institute of Physical and Chemical Research, Japan

    Application of AHP algorithm on power distribution of load shedding in island microgrid

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    This paper proposes a method of load shedding in a microgrid system operated in an Island Mode, which is disconnected with the main power grid and balanced loss of the electrical power. This proposed method calculates the minimum value of the shed power with reference to renewable energy sources such as wind power generator, solar energy and the ability to control the frequency of the generator to restore the frequency to the allowable range and reduce the amount of load that needs to be shed. Computing the load importance factor (LIF) using AHP algorithm supports to determine the order of which load to be shed. The damaged outcome of load shedding, thus, will be noticeably reduced. The experimental results of this proposed method is demonstrated by simulating on IEEE 16-Bus microgrid system with six power sources

    Single Z' production at CLIC based on e^- gamma collisions

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    We analyze the potential of CLIC based on e- gamma collisions to search for new Zâ€ČZ' gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed (RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can be observed at the CLIC, and the cross sections in the model with RH neutrinos are bigger than those in the minimal one.Comment: 11 pages, 4 figures, To appear in JET

    When can we reconstruct the ancestral state? Beyond Brownian motion

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    Reconstructing the ancestral state of a group of species helps answer many important questions in evolutionary biology. Therefore, it is crucial to understand when we can estimate the ancestral state accurately. Previous works provide a necessary and sufficient condition, called the big bang condition, for the existence of an accurate reconstruction method under discrete trait evolution models and the Brownian motion model. In this paper, we extend this result to a wide range of continuous trait evolution models. In particular, we consider a general setting where continuous traits evolve along the tree according to stochastic processes that satisfy some regularity conditions. We verify these conditions for popular continuous trait evolution models including Ornstein-Uhlenbeck, reflected Brownian Motion, and Cox-Ingersoll-Ross

    Co-infection of human parvovirus B19 with Plasmodium falciparum contributes to malaria disease severity in Gabonese patients

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    Background: High seroprevalence of parvovirus B19 (B19V) coinfection with Plasmodium falciparum has been previously reported. However, the impact of B19V-infection on the clinical course of malaria is still elusive. In this study, we investigated the prevalence and clinical significance of B19V co-infection in Gabonese children with malaria. Methods: B19V prevalence was analyzed in serum samples of 197 Gabonese children with P. falciparum malaria and 85 healthy controls using polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and direct DNA-sequencing. Results: B19V was detected in 29/282 (10.28%) of Gabonese children. B19V was observed more frequently in P. falciparum malaria patients (14.21%) in comparison to healthy individuals (1.17%) (

    Quartic Gauge Boson Couplings and Tree Unitarity in the SU(3)_C X SU(3)_L X U(1)_N Models

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    The quartic gauge boson couplings in the SU(3)C⊗SU(3)L⊗U(1)N{SU(3)}_C \otimes {SU(3)}_L \otimes {U(1)}_N models are presented. We find that the couplings of four {\it differrent} gauge bosons may have unusual Lorentz structure and the couplings sastify the tree unitarity requirement at high energy limit.Comment: 13 pages, Latex, axodraw.st
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