197,715 research outputs found

    Tailorable infrared sensing device with strain layer superlattice structure

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    An infrared photodetector is formed of a heavily doped p-type Ge sub x Si sub 1-x/Si superlattice in which x is pre-established during manufacture in the range 0 to 100 percent. A custom-tailored photodetector that can differentiate among close wavelengths in the range of 2.7 to 50 microns is fabricated by appropriate selection of the alloy constituency value, x, to establish a specific wavelength at which photodetection cutoff will occur

    Diffusion semigroup on manifolds with time-dependent metrics

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    Let Lt:=Δt+ZtL_t:=\Delta_t +Z_t , t∈[0,Tc)t\in [0,T_c) on a differential manifold equipped with time-depending complete Riemannian metric (gt)t∈[0,Tc)(g_t)_{t\in [0,T_c)}, where Δt\Delta_t is the Laplacian induced by gtg_t and (Zt)t∈[0,Tc)(Z_t)_{t\in [0,T_c)} is a family of C1,1C^{1,1}-vector fields. We first present some explicit criteria for the non-explosion of the diffusion processes generated by LtL_t; then establish the derivative formula for the associated semigroup; and finally, present a number of equivalent semigroup inequalities for the curvature lower bound condition, which include the gradient inequalities, transportation-cost inequalities, Harnack inequalities and functional inequalities for the diffusion semigroup

    LO-Net: Deep Real-time Lidar Odometry

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    We present a novel deep convolutional network pipeline, LO-Net, for real-time lidar odometry estimation. Unlike most existing lidar odometry (LO) estimations that go through individually designed feature selection, feature matching, and pose estimation pipeline, LO-Net can be trained in an end-to-end manner. With a new mask-weighted geometric constraint loss, LO-Net can effectively learn feature representation for LO estimation, and can implicitly exploit the sequential dependencies and dynamics in the data. We also design a scan-to-map module, which uses the geometric and semantic information learned in LO-Net, to improve the estimation accuracy. Experiments on benchmark datasets demonstrate that LO-Net outperforms existing learning based approaches and has similar accuracy with the state-of-the-art geometry-based approach, LOAM
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