16,181 research outputs found

    Real-Time Remaining Useful Life Prediction of Cutting Tools Using Sparse Augmented Lagrangian Analysis and Gaussian Process Regression

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    Remaining useful life (RUL) of cutting tools is concerned with cutting tool operational status prediction and damage prognosis. Most RUL prediction methods utilized different features collected from different sensors to predict the life of the tool. To increase the prediction accuracy, it is often necessary to mount a great deal of sensors on the machine in order to collect more types of signals, which can heavily increase the cost in industrial applications. To deal with this issue, this study, for the first time, proposed a new feature network dictionary, which can enlarge the number of candidate features under limited sensor conditions, and the developed dictionary can potentially contain as much useful information as possible. This process can replace the installation of more sensors and incorporate more information. Then, the sparse augmented Lagrangian (SAL) feature selection method is proposed to reduce the number of candidate features and select the most significant features. Finally, the selected features are input to the Gaussian Process Regression (GPR) model for the RUL estimation. Extensive experiments demonstrate that our proposed RUL estimation framework output performs traditional methods, especially for the cost savings for on-line RUL estimation

    Combined fit to BaBar and Belle data on e+e- to pi+pi- psi(2S)

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    A combined fit is performed to the BaBar and Belle measurements of the e+e- to pi+pi-psi(2S) cross sections for center-of-mass energy between threshold and 5.5 GeV. The resonant parameters of the Y(4360) and Y(4660) are determined. The mass is 4355^{+9}_{-10}\pm 9 MeV/c^2 and the width is 103^{+17}_{-15}\pm 11 MeV/c^2 for the Y(4360), and the mass is 4661^{+9}_{-8}\pm 6 MeV/c^2 and the width is 42^{+17}_{-12}\pm 6 MeV/c^2 for the Y(4660). The production of the Y(4260) in pi+pi-psi(2S) mode is found to be at 2\sigma level, and B(Y(4260) to pi+pi-psi(2S))\Gamma_{e+e-} is found to be less than 4.3 eV/c^2 at the 90% confidence level, or equal to 7.4^{+2.1}_{-1.7} eV/c^2 depending on it interferes with the Y(4360) constructively or destructively. These information will shed light on the understanding of the nature of the Y states observed in initial state radiation processes.Comment: 8 pages, 4 figure

    Large-time Behavior of Solutions to the Inflow Problem of Full Compressible Navier-Stokes Equations

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    Large-time behavior of solutions to the inflow problem of full compressible Navier-Stokes equations is investigated on the half line R+=(0,+∞)R^+ =(0,+\infty). The wave structure which contains four waves: the transonic(or degenerate) boundary layer solution, 1-rarefaction wave, viscous 2-contact wave and 3-rarefaction wave to the inflow problem is described and the asymptotic stability of the superposition of the above four wave patterns to the inflow problem of full compressible Navier-Stokes equations is proven under some smallness conditions. The proof is given by the elementary energy analysis based on the underlying wave structure. The main points in the proof are the degeneracies of the transonic boundary layer solution and the wave interactions in the superposition wave.Comment: 27 page
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