164 research outputs found
Vanishing of the anomalous Hall effect and enhanced carrier mobility in the spin-gapless ferromagnetic Mn2CoGa1-xAlx alloys
Spin gapless semiconductor (SGS) has attracted long attention since its
theoretical prediction, while concrete experimental hints are still lack in the
relevant Heusler alloys. Here in this work, by preparing the series alloys of
Mn2CoGa1-xAlx (x=0, 0.25, 0.5, 0.75 and 1), we identified the vanishing of
anomalous Hall effect in the ferromagnetic Mn2CoGa (or x=0.25) alloy in a wide
temperature interval, accompanying with growing contribution from the ordinary
Hall effect. As a result, comparatively low carrier density (1020 cm-3) and
high carrier mobility (150 cm2/Vs) are obtained in Mn2CoGa (or x=0.25) alloy in
the temperature range of 10-200K. These also lead to a large dip in the related
magnetoresistance at low fields. While in high Al content, despite the
magnetization behavior is not altered significantly, the Hall resistivity is
instead dominated by the anomalous one, just analogous to that widely reported
in Mn2CoAl. The distinct electrical transport behavior of x=0 and x=0.75 (or 1)
is presently understood by their possible different scattering mechanism of the
anomalous Hall effect due to the differences in atomic order and conductivity.
Our work can expand the existing understanding of the SGS properties and offer
a better SGS candidate with higher carrier mobility that can facilitate the
application in the spin-injected related devices
Robustness-Guided Image Synthesis for Data-Free Quantization
Quantization has emerged as a promising direction for model compression.
Recently, data-free quantization has been widely studied as a promising method
to avoid privacy concerns, which synthesizes images as an alternative to real
training data. Existing methods use classification loss to ensure the
reliability of the synthesized images. Unfortunately, even if these images are
well-classified by the pre-trained model, they still suffer from low semantics
and homogenization issues. Intuitively, these low-semantic images are sensitive
to perturbations, and the pre-trained model tends to have inconsistent output
when the generator synthesizes an image with poor semantics. To this end, we
propose Robustness-Guided Image Synthesis (RIS), a simple but effective method
to enrich the semantics of synthetic images and improve image diversity,
further boosting the performance of downstream data-free compression tasks.
Concretely, we first introduce perturbations on input and model weight, then
define the inconsistency metrics at feature and prediction levels before and
after perturbations. On the basis of inconsistency on two levels, we design a
robustness optimization objective to enhance the semantics of synthetic images.
Moreover, we also make our approach diversity-aware by forcing the generator to
synthesize images with small correlations in the label space. With RIS, we
achieve state-of-the-art performance for various settings on data-free
quantization and can be extended to other data-free compression tasks.Comment: Accepted at AAAI 202
The linkages between stomatal physiological traits and rapid expansion of exotic mangrove species (Laguncularia racemosa) in new territories
The fast-growing exotic mangrove species (Laguncularia racemosa) has been widely introduced in new territories such as China to restore mangrove ecosystems. However, the invasiveness, as well as the mechanisms for the rapid expansion after the introduction are still not well studied. Here, we try to reveal possible micro-mechanisms for the fast expansion of L. racemosa, using the data on leaf stomata straits, gas-exchange parameters, stable isotope ratios, carbon-nitrogen allocation from L. racemosa and the adjacent native mangroves (Avicennia marina, Aegiceras corniculatum, Bruguiera gymnorhiza, Kandelia obovata) in Hainan Island, China. We found that the higher density but smaller size stoma of L. racemosa enhanced stomatal conductance and shorten the diffusion path of carbon dioxide, thereby increasing the photosynthetic rate. Moreover, the higher stomatal density of L. racemosa exerts a significant positive effect on transpiration, which thus accelerated the water transport and nutrient uptake to meet the advanced need for nutrients and water for fast-growing. The evidence from leaf δ13C and carbon-nitrogen allocation further proved that L. racemosa has a lower intrinsic water use efficiency but a higher rate of photosynthesis than native mangrove species. Our results suggest that stomatal morphological and physiological traits could strongly influence the growth of L. racemosa compared to the adjacent native mangroves, which provides a new perspective for the fast expansion of exotic mangrove species in China. These findings also suggest that L. racemosa has an invasive potential in native mangrove habitats, thereby the mangrove reforestation projects by introducing L. racemosa should be treated with caution
Milestones in Autonomous Driving and Intelligent Vehicles Part II: Perception and Planning
Growing interest in autonomous driving (AD) and intelligent vehicles (IVs) is
fueled by their promise for enhanced safety, efficiency, and economic benefits.
While previous surveys have captured progress in this field, a comprehensive
and forward-looking summary is needed. Our work fills this gap through three
distinct articles. The first part, a "Survey of Surveys" (SoS), outlines the
history, surveys, ethics, and future directions of AD and IV technologies. The
second part, "Milestones in Autonomous Driving and Intelligent Vehicles Part I:
Control, Computing System Design, Communication, HD Map, Testing, and Human
Behaviors" delves into the development of control, computing system,
communication, HD map, testing, and human behaviors in IVs. This part, the
third part, reviews perception and planning in the context of IVs. Aiming to
provide a comprehensive overview of the latest advancements in AD and IVs, this
work caters to both newcomers and seasoned researchers. By integrating the SoS
and Part I, we offer unique insights and strive to serve as a bridge between
past achievements and future possibilities in this dynamic field.Comment: 17pages, 6figures. IEEE Transactions on Systems, Man, and
Cybernetics: System
Motion Planning for Autonomous Driving: The State of the Art and Future Perspectives
Thanks to the augmented convenience, safety advantages, and potential
commercial value, Intelligent vehicles (IVs) have attracted wide attention
throughout the world. Although a few autonomous driving unicorns assert that
IVs will be commercially deployable by 2025, their implementation is still
restricted to small-scale validation due to various issues, among which precise
computation of control commands or trajectories by planning methods remains a
prerequisite for IVs. This paper aims to review state-of-the-art planning
methods, including pipeline planning and end-to-end planning methods. In terms
of pipeline methods, a survey of selecting algorithms is provided along with a
discussion of the expansion and optimization mechanisms, whereas in end-to-end
methods, the training approaches and verification scenarios of driving tasks
are points of concern. Experimental platforms are reviewed to facilitate
readers in selecting suitable training and validation methods. Finally, the
current challenges and future directions are discussed. The side-by-side
comparison presented in this survey not only helps to gain insights into the
strengths and limitations of the reviewed methods but also assists with
system-level design choices.Comment: 20 pages, 14 figures and 5 table
Comprehensive epigenetic landscape of rheumatoid arthritis fibroblast-like synoviocytes.
Epigenetics contributes to the pathogenesis of immune-mediated diseases like rheumatoid arthritis (RA). Here we show the first comprehensive epigenomic characterization of RA fibroblast-like synoviocytes (FLS), including histone modifications (H3K27ac, H3K4me1, H3K4me3, H3K36me3, H3K27me3, and H3K9me3), open chromatin, RNA expression and whole-genome DNA methylation. To address complex multidimensional relationship and reveal epigenetic regulation of RA, we perform integrative analyses using a novel unbiased method to identify genomic regions with similar profiles. Epigenomically similar regions exist in RA cells and are associated with active enhancers and promoters and specific transcription factor binding motifs. Differentially marked genes are enriched for immunological and unexpected pathways, with "Huntington's Disease Signaling" identified as particularly prominent. We validate the relevance of this pathway to RA by showing that Huntingtin-interacting protein-1 regulates FLS invasion into matrix. This work establishes a high-resolution epigenomic landscape of RA and demonstrates the potential for integrative analyses to identify unanticipated therapeutic targets
UniSeg: A Unified Multi-Modal LiDAR Segmentation Network and the OpenPCSeg Codebase
Point-, voxel-, and range-views are three representative forms of point
clouds. All of them have accurate 3D measurements but lack color and texture
information. RGB images are a natural complement to these point cloud views and
fully utilizing the comprehensive information of them benefits more robust
perceptions. In this paper, we present a unified multi-modal LiDAR segmentation
network, termed UniSeg, which leverages the information of RGB images and three
views of the point cloud, and accomplishes semantic segmentation and panoptic
segmentation simultaneously. Specifically, we first design the Learnable
cross-Modal Association (LMA) module to automatically fuse voxel-view and
range-view features with image features, which fully utilize the rich semantic
information of images and are robust to calibration errors. Then, the enhanced
voxel-view and range-view features are transformed to the point space,where
three views of point cloud features are further fused adaptively by the
Learnable cross-View Association module (LVA). Notably, UniSeg achieves
promising results in three public benchmarks, i.e., SemanticKITTI, nuScenes,
and Waymo Open Dataset (WOD); it ranks 1st on two challenges of two benchmarks,
including the LiDAR semantic segmentation challenge of nuScenes and panoptic
segmentation challenges of SemanticKITTI. Besides, we construct the OpenPCSeg
codebase, which is the largest and most comprehensive outdoor LiDAR
segmentation codebase. It contains most of the popular outdoor LiDAR
segmentation algorithms and provides reproducible implementations. The
OpenPCSeg codebase will be made publicly available at
https://github.com/PJLab-ADG/PCSeg.Comment: ICCV 2023; 21 pages; 9 figures; 18 tables; Code at
https://github.com/PJLab-ADG/PCSe
- …