280 research outputs found
Falconer distance problem on Riemannian manifolds with constant sectional curvature
For even, we prove that on a -dimensional Riemannian manifold with
constant sectional curvature, the distance set of a Borel set has positive
Lebesgue measure if the Hausdorff dimension of is greater than Comment: 18 page
Microlocal decoupling inequalities and the distance problem on Riemannian manifolds
We study the generalization of the Falconer distance problem to the
Riemannian setting. In particular, we extend the result of
Guth-Iosevich-Ou-Wang for the distance set in the plane to general Riemannian
surfaces. Key new ingredients include a family of refined microlocal decoupling
inequalities, which are related to the work of Beltran-Hickman-Sogge on
Wolff-type inequalities, and an analog of Orponen's radial projection lemma
which has proved quite useful in recent work on distance sets.Comment: 36 pages, 2 figures, Referee's suggestions incorporate
Improved local smoothing estimate for the wave equation in higher dimensions
In this paper, we establish the sharp -broad estimate for a class of phase
functions satisfying the homogeneous convex conditions. As an application, we
obtain improved local smoothing estimates for the half-wave operator in
dimensions . As a byproduct, we also generalize the restriction
estimates of Ou--Wang to a broader class of phase functions.Comment: 32 pages, 3 figures, Referees' suggestions incorporated. To appear in
J. Func. Ana
Visualization of out-of-plane spin generation in mirror symmetry broken Co
Generating out-of-plane spins in sputtered materials holds immense potential
for achieving field-free spin-orbit torque switching in practical applications
and mass production. In this work, we present the detection of out-of-plane
spins from single-layer ferromagnetic Co layers, which are visualized through
helicity-dependent photomapping techniques. Our experiments have shown that
out-of-plane spin generation is dependent on the magnetization direction,
current density, and Co thickness. Our findings indicate that amorphous
sputtered Co can be a promising candidate as an out-of-plane spin source
material for industrial massive production.Comment: 5 figure
Boundary-semantic collaborative guidance network with dual-stream feedback mechanism for salient object detection in optical remote sensing imagery
With the increasing application of deep learning in various domains, salient
object detection in optical remote sensing images (ORSI-SOD) has attracted
significant attention. However, most existing ORSI-SOD methods predominantly
rely on local information from low-level features to infer salient boundary
cues and supervise them using boundary ground truth, but fail to sufficiently
optimize and protect the local information, and almost all approaches ignore
the potential advantages offered by the last layer of the decoder to maintain
the integrity of saliency maps. To address these issues, we propose a novel
method named boundary-semantic collaborative guidance network (BSCGNet) with
dual-stream feedback mechanism. First, we propose a boundary protection
calibration (BPC) module, which effectively reduces the loss of edge position
information during forward propagation and suppresses noise in low-level
features without relying on boundary ground truth. Second, based on the BPC
module, a dual feature feedback complementary (DFFC) module is proposed, which
aggregates boundary-semantic dual features and provides effective feedback to
coordinate features across different layers, thereby enhancing cross-scale
knowledge communication. Finally, to obtain more complete saliency maps, we
consider the uniqueness of the last layer of the decoder for the first time and
propose the adaptive feedback refinement (AFR) module, which further refines
feature representation and eliminates differences between features through a
unique feedback mechanism. Extensive experiments on three benchmark datasets
demonstrate that BSCGNet exhibits distinct advantages in challenging scenarios
and outperforms the 17 state-of-the-art (SOTA) approaches proposed in recent
years. Codes and results have been released on GitHub:
https://github.com/YUHsss/BSCGNet.Comment: Accepted by TGR
Estimation of flow direction in meandering compound channels
YesThe flow in the main channel of a meandering compound channel does not occur in the ridge direction because of the effect of the upstream floodplain flows. This study proposes a model for estimating the flow direction in the depth-averaged two-dimensional domain (depth-averaged flow angles) between the entrance and the apex sections. Detailed velocity measurements were performed in the region between the meander entrance section and apex section in a large-scale meandering compound channel. The vertical size of the secondary current cell is highly related to the depth-averaged flow angle; thus, the means of the local flow angles above the secondary current cell and within the cell are separately discussed. The experimental measurements indicate that the mean local flow angle above the cell is equal to the section angle, whereas the mean local flow angle within the cell is equal to zero. The proposed model is validated using published data from five sources. Good agreement is obtained between the predictions and measurements, indicating that the proposed model can accurately estimate the depth-averaged flow direction in the meandering compound channels. Finally, the limitations and application ranges of the model are discussed.National Key Research and Development Program of China (No. 2016YFC0402302), the National Natural Science Foundation of China (Nos. 51539007 and 51609160
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