1,855 research outputs found

    A New Method for Figuring the Number of Hidden Layer Nodes in BP Algorithm

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    In the field of artificial neural network, BP neural network is a multi-layer feed-forward neural network. Because it is difficult to figure the number of hidden layer nodes in a BP neural network, the theoretical basis and the existing methods for BP network hidden layer nodes are studied. Then based on traditional empirical formulas, we propose a new approach to rapidly figure the quantity of hidden layer nodes in two-layer network. That is, with the assistance of experience formulas, the horizon of unit number in hidden layer can be confirmed and its optimal value will be found in this horizon. Finally, a new formula for figuring the quantity of hidden layer codes is obtained through fitting input dimension, output dimension and the optimal value of hidden layer codes. Under some given input dimension and output dimension, efficiency and precision of BP algorithm may be improved by applying the proposed formula

    (E)-N′-(5-Bromo-2-hy­droxy­benzyl­idene)-3-methyl­benzohydrazide

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    In the title mol­ecule, C15H13BrN2O2, an intra­molecular O—H⋯N hydrogen bond influences the mol­ecular conformation; the two benzene rings form a dihedral angle of 13.6 (3)°. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains along the a axis and weak inter­molecular C—H⋯O hydrogen bonds further link these chains into layers parallel to the ac plane

    On the Momentum Dependence of the Flavor Structure of the Nucleon Sea

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    Difference between the uˉ\bar u and dˉ\bar d sea quark distributions in the proton was first observed in the violation of the Gottfried sum rule in deep-inelastic scattering (DIS) experiments. The parton momentum fraction xx dependence of this difference has been measured over the region 0.02<x<0.350.02 < x < 0.35 from Drell-Yan and semi-inclusive DIS experiments. The Drell-Yan data suggested a possible sign-change for dˉ(x)uˉ(x)\bar d(x)-\bar u(x) near x0.3x \sim 0.3, which has not yet been explained by existing theoretical models. We present an independent evidence for the dˉ(x)uˉ(x)\bar d(x)-\bar u(x) sign-change at x0.3x \sim 0.3 from an analysis of the DIS data. We further discuss the xx-dependence of dˉ(x)uˉ(x)\bar d(x)-\bar u(x) in the context of meson cloud model and the lattice QCD formulation.Comment: 5 pages, 5 figures, final versio

    Topological phase transition in a narrow bandgap semiconductor nanolayer

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    Narrow bandgap semiconductor nanostructures have been explored for realization of topological superconducting quantum devices in which Majorana states can be created and employed for constructing topological qubits. However, a prerequisite to achieve the topological phase transition in these nanostructures is application of a magnetic field, which could complicate the technology development towards topological quantum computing. Here we demonstrate that a topological phase transition can be achieved in a narrow bandgap semiconductor nanolayer under application of a perpendicular electric field. Based on full band structure calculations, it is shown that the topological phase transition occurs at an electric-field induced band inversion and is accompanied by a sharp change of the Z2\mathbb{Z}_{2} invariant at the critical field. We also demonstrate that the nontrivial topological phase is manifested by the quantum spin Hall edge states in a band-inverted nanolayer Hall-bar structure. We present the phase diagram of the nanolayer in the space of layer thickness and electric field strength, and discuss the optimal conditions to achieve a large topological bandgap in the electric-field induced topological phase of a semiconductor nanolayer.Comment: 6 pages, 5 figure

    Effectiveness of influenza vaccination in patients with end-stage renal disease receiving hemodialysis: a population-based study.

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    BackgroundLittle is known on the effectiveness of influenza vaccine in ESRD patients. This study compared the incidence of hospitalization, morbidity, and mortality in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) between cohorts with and without influenza vaccination.MethodsWe used the insurance claims data from 1998 to 2009 in Taiwan to determine the incidence of these events within one year after influenza vaccination in the vaccine (N = 831) and the non-vaccine (N = 3187) cohorts. The vaccine cohort to the non-vaccine cohort incidence rate ratio and hazard ratio (HR) of morbidities and mortality were measured.ResultsThe age-specific analysis showed that the elderly in the vaccine cohort had lower hospitalization rate (100.8 vs. 133.9 per 100 person-years), contributing to an overall HR of 0.81 (95% confidence interval (CI) 0.72-0.90). The vaccine cohort also had an adjusted HR of 0.85 [95% CI 0.75-0.96] for heart disease. The corresponding incidence of pneumonia and influenza was 22.4 versus 17.2 per 100 person-years, but with an adjusted HR of 0.80 (95% CI 0.64-1.02). The vaccine cohort had lowered risks than the non-vaccine cohort for intensive care unit (ICU) admission (adjusted HR 0.20, 95% CI 0.12-0.33) and mortality (adjusted HR 0.50, 95% CI 0.41-0.60). The time-dependent Cox model revealed an overall adjusted HR for mortality of 0.30 (95% CI 0.26-0.35) after counting vaccination for multi-years.ConclusionsESRD patients with HD receiving the influenza vaccination could have reduced risks of pneumonia/influenza and other morbidities, ICU stay, hospitalization and death, particularly for the elderly

    A genome-wide synthetic dosage lethality screen reveals multiple pathways that require the functioning of ubiquitin-binding proteins Rad23 and Dsk2

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    <p>Abstract</p> <p>Background</p> <p>Ubiquitin regulates a myriad of important cellular processes through covalent attachment to its substrates. A classic role for ubiquitin is to flag proteins for destruction by the proteasome. Recent studies indicate that ubiquitin-binding proteins (e.g. Rad23, Dsk2, Rpn10) play a pivotal role in transferring ubiquitylated proteins to the proteasome. However, the specific role of these ubiquitin receptors remains poorly defined. A key to unraveling the functions of these ubiquitin receptors is to identify their cellular substrates and biological circuits they are involved in. Although many strategies have been developed for substrate isolation, the identification of physiological targets of proteolytic pathways has proven to be quite challenging.</p> <p>Results</p> <p>Using a genome-wide functional screen, we have identified 11 yeast genes that cause slower growth upon their overexpression in cells lacking two ubiquitin-binding proteins Rad23 and Dsk2. Our results suggest that proper functioning of Rad23 and Dsk2 is required for efficient pheromone response, transcription, amino acid metabolism, and DNA damage response. Two proteins identified by the screen are shown to be proteolytic substrates of Dsk2, validating the large scale synthetic dosage lethality screen as a new strategy for identifying substrates of a specific degradation pathway.</p> <p>Conclusion</p> <p>In conclusion, as proof-of-concept, we show that a synthetic dosage lethality screen, which is based on the toxicity induced by gene overexpression, offers an effective, complementary method to elucidating biological functions of proteolytic pathways.</p

    Deep Learning the Effects of Photon Sensors on the Event Reconstruction Performance in an Antineutrino Detector

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    We provide a fast approach incorporating the usage of deep learning for evaluating the effects of photon sensors in an antineutrino detector on the event reconstruction performance therein. This work is an attempt to harness the power of deep learning for detector designing and upgrade planning. Using the Daya Bay detector as a benchmark case and the vertex reconstruction performance as the objective for the deep neural network, we find that the photomultiplier tubes (PMTs) have different relative importance to the vertex reconstruction. More importantly, the vertex position resolutions for the Daya Bay detector follow approximately a multi-exponential relationship with respect to the number of PMTs and hence, the coverage. This could also assist in deciding on the merits of installing additional PMTs for future detector plans. The approach could easily be used with other objectives in place of vertex reconstruction

    Electrically-controllable RKKY interaction in semiconductor quantum wires

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    We demonstrate in theory that it is possible to all-electrically manipulate the RKKY interaction in a quasi-one-dimensional electron gas embedded in a semiconductor heterostructure, in the presence of Rashba and Dresselhaus spin-orbit interaction. In an undoped semiconductor quantum wire where intermediate excitations are gapped, the interaction becomes the short-ranged Bloembergen-Rowland super-exchange interaction. Owing to the interplay of different types of spin-orbit interaction, the interaction can be controlled to realize various spin models, e.g., isotropic and anisotropic Heisenberg-like models, Ising-like models with additional Dzyaloshinsky-Moriya terms, by tuning the external electric field and designing the crystallographic directions. Such controllable interaction forms a basis for quantum computing with localized spins and quantum matters in spin lattices.Comment: 5 pages, 1 figur

    Muon anomalous magnetic dipole moment in the μν\mu\nuSSM

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    Recently, the Muon g-2 experiment at Fermilab has measured the muon anomalous magnetic dipole moment (MDM), which reported that the new experimental average increases the tension between experiment and the standard model (SM) prediction to 4.2 standard deviations, after combination with the previous Brookhaven National Laboratory (BNL) E821 measurement. In this work, we reanalyse the muon anomalous MDM at two-loop level in the μ\mu from ν\nu Supersymmetric Standard Model (μν\mu\nuSSM) combined with the updated experimental average. The μν\mu\nuSSM can explain the current tension between the experimental measurement and the SM theoretical prediction for the muon anomalous MDM, constrained by the 125 GeV Higgs boson mass and decays, the rare decay BˉXsγ\bar{B}\rightarrow X_s\gamma and so on.Comment: 14 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:2002.04370, arXiv:2011.0428
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