11 research outputs found

    LEO-satellite-assisted UAV: joint trajectory and data collection for Internet of Remote Things in 6G aerial access networks

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    As the sixth generation (6G) network is under research, and one important issue is the aerial access network and terrestrial-space integration. The Internet of Remote Things (IoRT) sensors can access the unmanned aerial vehicles (UAVs) in the air, and low Earth orbit (LEO) satellite networks in the space help to provide lower transmission delay for delay-sensitive IoRT data. Therefore, in this article, we consider the LEO satellite-assisted UAV data collection for the IoRT sensors. Specifically, a UAV collects the data from the IoRT sensors, then two transmission modes for the collected data back to Earth: 1) the delay-tolerant data leveraging the carry-store mode of UAVs to Earth and 2) the delay-sensitive data utilizing the UAV-satellite network transmission to Earth. Considering the limited payloads of UAVs, we focus on minimizing the total energy cost (trajectory and transmission) of UAVs while satisfying the IoRT demands. Due to the intractability of direct solution, we deal with the problem using the Dantzig-Wolfe decomposition and design the column generation-based algorithms to efficiently solve the problem. Moreover, we present a heuristic algorithm for the subproblem to further reduce the complexity of large-scale networks. Finally, numerical results verify the efficiency of the proposed algorithms and the advantage of LEO satellite-assisted UAV trajectory design combined with the data transmission is also analyzed.This work was supported in part by the Natural Science Foundation of China under Grant U19B2025, Grant 61725103, Grant 61701363, and Grant 61931005; and in part by the Doctoral Students' Short-Term Study Abroad Scholarship Fund of Xidian University

    Routing Recovery for UAV Networks with Deliberate Attacks: A Reinforcement Learning based Approach

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    The unmanned aerial vehicle (UAV) network is popular these years due to its various applications. In the UAV network, routing is significantly affected by the distributed network topology, leading to the issue that UAVs are vulnerable to deliberate damage. Hence, this paper focuses on the routing plan and recovery for UAV networks with attacks. In detail, a deliberate attack model based on the importance of nodes is designed to represent enemy attacks. Then, a node importance ranking mechanism is presented, considering the degree of nodes and link importance. However, it is intractable to handle the routing problem by traditional methods for UAV networks, since link connections change with the UAV availability. Hence, an intelligent algorithm based on reinforcement learning is proposed to recover the routing path when UAVs are attacked. Simulations are conducted and numerical results verify the proposed mechanism performs better than other referred methods.Comment: IEEE GLOBECOM 2023, 6 pages, 4 figure

    A bifunctional MnxCo3-xO4-decorated separator for efficient Li-LiI-O2 batteries : A novel strategy to promote redox coupling and inhibit redox shuttling

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    Although redox mediator (RM) strategy can decrease the overpotential in Li-O2 batteries by tuning the electrochemical formation/degradation of Li2O2 from the circumscribed surface pathway to the solution one, the redox shuttling causes an unexpected RM degradation and a continuous deterioration of Li anode, finally leading to a poor cyclability. This work presents the first report detailing the development of a novel MnxCo3-xO4-decorated separator for Li-LiI-O2 batteries. Benefiting from the promotion effect of MnxCo3-xO4 nanocages on I−/I3− and I3−/I2 redox coupling, the cell with as-prepared separator maintains a low charge potential of ~3.3 V till the death of cell cycling. In addition, as-prepared separator can efficiently restrain the redox shuttling, leading to an obvious improvement on cycling stability for the cell. Moreover, the contributions of LiI to the battery performance and the operation mechanism are systematically investigated. These results present a promising progress in the development of multi-functional separator materials for RM-involved Li-O2 batteries and the new design of hybrid energy storage device.Title in Web of Science: A bifunctional MnxCo3-xO4-decorated separator for efficient Li-LiI-O-2 batteries: A novel strategy to promote redox coupling and inhibit redox shuttling</p

    Elevated expression of hsa_circ_0000479 in neutrophils correlates with features of systemic lupus erythematosus

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    AbstractObjective Accumulating evidence suggests that differentially expressed circular RNAs (circRNAs) play critical roles in immune cells of systemic lupus erythematosus (SLE) patients. Hsa_circ_0000479 has been studied in the field of cancer and infection, whereas seldom studied in autoimmune diseases. The aim of this study was to investigate the role and clinical value of neutrophil hsa_circ_0000479 in SLE.Methods The expression levels of hsa_circ_0000479 in both healthy individuals and SLE patients’ neutrophils were detected by qPCR and compared with those in peripheral blood mononuclear cells (PBMCs) . In addition, the correlation of hsa_circ_0000479 levels in neutrophils with the clinical and immunological features of SLE patients was also analysed.Results The expression levels of hsa_circ_0000479 in the patients with SLE were significantly higher in neutrophils than that of PBMCs, and also significantly higher than that in healthy controls (HCs). Moreover, the expression levels of hsa_circ_0000479 in neutrophils were negatively associated with absolute neutrophil count and complement 3 (C3), whereas positively correlated with anti-dsDNA and anti-nucleosome antibodies in SLE. In addition, SLE patients with higher levels of hsa_circ_0000479 demonstrated more several clinical manifestations, including Raynaud’s phenomenon, alopecia and leucopenia.Conclusions Hsa_circ_0000479 is up-regulated in neutrophils of SLE patients, and is also associated with several important laboratory indicators and clinical manifestations, suggesting that hsa_circ_0000479 in neutrophils was one of probable factors involved in the pathogenesis of SLE with potential clinical value
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