Quantum Borcherds-Bozec algebras via semi-derived Ringel-Hall algebras II: braid group actions

Based on the realization of quantum Borcherds-Bozec algebra $\widetilde{\mathbf{U}}$ and quantum generalized Kac-Moody algebra ${}^B\widetilde{\mathbf{U}}$ via semi-derived Ringel-Hall algebra of a quiver with loops, we deduce the braid group actions of $\widetilde{\mathbf{U}}$ introduced by Fan and Tong recently and establish braid group actions for ${}^B\widetilde{\mathbf{U}}$ by applying the BGP reflection functors to semi-derived Ringel-Hall algebras.Comment: 18 pages, minor changes, accepted by Bulletin of the London Mathematical Society. arXiv admin note: substantial text overlap with arXiv:2107.0316

Light-LOAM: A Lightweight LiDAR Odometry and Mapping based on Graph-Matching

Simultaneous Localization and Mapping (SLAM) plays an important role in robot autonomy. Reliability and efficiency are the two most valued features for applying SLAM in robot applications. In this paper, we consider achieving a reliable LiDAR-based SLAM function in computation-limited platforms, such as quadrotor UAVs based on graph-based point cloud association. First, contrary to most works selecting salient features for point cloud registration, we propose a non-conspicuous feature selection strategy for reliability and robustness purposes. Then a two-stage correspondence selection method is used to register the point cloud, which includes a KD-tree-based coarse matching followed by a graph-based matching method that uses geometric consistency to vote out incorrect correspondences. Additionally, we propose an odometry approach where the weight optimizations are guided by vote results from the aforementioned geometric consistency graph. In this way, the optimization of LiDAR odometry rapidly converges and evaluates a fairly accurate transformation resulting in the back-end module efficiently finishing the mapping task. Finally, we evaluate our proposed framework on the KITTI odometry dataset and real-world environments. Experiments show that our SLAM system achieves a comparative level or higher level of accuracy with more balanced computation efficiency compared with the mainstream LiDAR-based SLAM solutions

Synthesis and electrochemical performances of MoS2/C fibers as anode material for lithium-ion battery

The electronspinning method is used to synthesize MoS2/C composite. The MoS2/C composite takes on the morphology of nano-fibers with diameters between 50 and 150 nm. Electrochemical tests demonstrated that MoS2/C nanofibers have a high reversible discharge capacity (650 mA h g-1) and outstanding rate performances. The MoS2/C nanofibers are promising anode material for lithium ion battery

Allelopathic effects of euhalophyte Salicornia bigelovii on marine alga Skeletonema costatum

Harmful algal bloom (HAB), caused by intense eutrophication, are threatening the biodiversity and ecological function of marine ecosystems. We studied the potential allelopathy of Salicornia bigelovii, a euhalophyte, to inhibit the growth of Skeletonema costatum, a marine bloom forming diatom. Experiments were done in 3 culture systems (alga +euhalophyte co-culture, monoculture of marine alga, monoculture of euhalophyte) to determine the allelopathic effect of S. bigelovii against S. costatum. Lower nutrient removal rate by S. bigelovii was observed in co-culture system compared to monoculture system. The chlorophyll a and cell density of S. costatum in co-culture system were much lower than in alga monoculture system. Moreover, the aqueous extract from S. bigelovii roots showed dose-dependent inhibition against the algal growth and the half maximal inhibitory concentration (IC(50)) of root extract was 10.37 g FW L(-1). Therefore, rather than nutrient competition, allelopathy was accounted for the growth inhibition of S. costatum by S. bigelovii. Our finding implies that S. bigelovii, as a euhalophyte, may play an active role in HAB prevention