作者机构：
[Xie, Shujing; Wang, Minghua; Zhu, Ziyan; Wang, Yan] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Wang, Y ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词：
geographic routing;link detection and repair;node collaborative scheduling;energy optimization
摘要：
Energy efficiency and data reliability are important indicators to measure network performance in wireless sensor networks. In existing research schemes of routing protocols, the impact of node coverage on the network is often ignored, and the possibility that multiple sensor nodes may sense the same spatial point is not taken into account, which results in a waste of network resources, especially in large-scale networks. Apart from that, the blindness of geographic routing in data transmission has been troubling researchers, which means that the nodes are unable to determine the validity of data transmission. In order to solve the above problems, this paper innovatively combines the routing protocol with the coverage control technique and proposes the node collaborative scheduling algorithm, which fully considers the correlation characteristics between sensor nodes to reduce the number of active working nodes and the number of packets generated, to further reduce energy consumption and network delay and improve packet delivery rate. In order to solve the problem of unreliability of geographic routing, a highly reliable link detection and repair scheme is proposed to check the communication link status and repair the invalid link, which can greatly improve the packet delivery rate and throughput of the network, and has good robustness. A large number of experiments demonstrate the effectiveness and superiority of our proposed scheme and algorithm.
摘要：
An improved metallized polyethylene terephthalate (PET) substrate prepared by catechol (CA) and tetraethylenepentamine (TEPA) composites modification with electroless deposition (ELD) copper layer is presented. Through the polymerization of CA with TEPA, amino and imino groups were generated to adsorb the activated particles required for metallization. To achieve the practical application of this method, different catalytic approaches were validated. Under different catalytic conditions, the catalytic effect of UV light was most pronounced, reaching almost four times than that in darkness. The resulting solid copper layers exhibited highly reliable electrical properties, including a low resistivity of 2.73 mu omega cm, tightly spaced crystalline particles and excellent mechanical properties. The fabricated metallized PET substrates were verified for use in flexible circuit boards, demonstrating the compatibility of the proposed CA-TEPA composites modification method with the PET substrates. This method provides an effective approach to the metallization of the PET substrates, which has a widespread application in manufacturing of flexible electronics such as film capacitors.
摘要：
This article presents a novel online adaptive method for estimating the process and measurement noise covariance matrices in Kalman filters (KFs) to address the challenge of varying noise characteristics in practical applications. Specifically, the proposed method decomposes the noise covariance matrix into an element distribution matrix and a noise intensity and employs an improved Sage filter to estimate the element distribution matrix. Additionally, a calibration and correction method is introduced to accurately determine and adaptively correct the online bias of the noise intensity. The unbiasedness and convergence of the proposed method are mathematically proven under the condition that the system is detectable. Moreover, this method is applied to multiobject tracking (MOT) based on KFs and light detection and ranging (LiDAR), and it is evaluated on the KITTI dataset and the official KITTI server. The experimental results demonstrate that the proposed method achieves significantly improved MOT performance based on KFs and outperforms other LiDAR-based methods on the KITTI leaderboard. This method provides a new approach for enhancing the performance of KFs and assisting with MOT, and it has practical feasibility for real-world applications.
作者机构：
[Zhang, Yang; Wu, Weichang; Huang, Youta; Qiu, Weibao; Zhang, Zhiqiang] Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 508055 China;[Zhang, Yang; Wu, Weichang; Huang, Youta; Qiu, Weibao; Zhang, Zhiqiang] The Key Laboratory of Biomedical Imaging Science and System, Chinese Academy of Sciences, Shenzhen 518055, China;[Huang, Youta] National-Reginoal Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory of Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen 518060, China;[Huang, Youta] Shenzhen Key Laboratory of Ultrasound Imaging and Therapy, Shenzhen 518055, China;[Zhang, Yang] School of Electrical Engineering, University of South China, Hengyang, China
通讯机构：
[Qiu, Weibao; Zhang, Zhiqiang] S;[Yu, Yanyan] N;National-Reginoal Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory of Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen 518060, China<&wdkj&>Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 508055 China<&wdkj&>The Key Laboratory of Biomedical Imaging Science and System, Chinese Academy of Sciences, Shenzhen 518055, China<&wdkj&>Shenzhen Key Laboratory of Ultrasound Imaging and Therapy, Shenzhen 518055, China
关键词：
Acoustic droplet ejection;Annular array transducer;Fast liquid transfer
摘要：
Acoustic droplet ejection (ADE) has become the preferred method for liquid transfer in a variety of applications including synthetic biology, genotyping and drug discovery. Comparing with traditional pipetting techniques, the accuracy and data reproducibility of ADE based liquid transfer are improved, waste and cost are reduced, and cross-contamination is eliminated. The key component in the ADE system is the ultrasound transducer, which is responsible for generating focused ultrasound beam for droplet ejection. However, current ADE systems commonly utilize a single-element focused transducer with a fixed focal length that require mechanical movement to focus on the liquid surface, resulting in reduced liquid transfer efficiency. In this study, we first present a high-frequency annular array transducer for the ADE technology, which enables rapid and dynamic axial focusing to the liquid surface without mechanically moving the transducer, thereby accelerating liquid transfer. Experimental results show that the proposed 10MHz, 5-element annular array transducer has good dynamic axial focusing ability, and can achieve accurate and stable droplet ejection of nanoliter volume at the designed focal length of 26-32mm. Our results highlight the potential of the annular array transducer in advancing ADE system for rapid liquid transfer. This technology is expected to be useful in a variety of applications where precise and high-throughput liquid transfer is crucial.
摘要：
Energy is still one of the most important problems in wireless sensor network (WSN). With the application of wireless charging vehicle (WCV), wireless charging technology can be used to solve the energy problem of WSN. In the wireless rechargeable sensor network (WRSN), how to reasonably deploy the WCV has become a problem in planning. The existing studies only consider the impact of independent coverage contribution of a single node on the charging path planning, but do not consider the redundant coverage area that may occur when a single node works independently, resulting in a small or even zero coverage contribution of some nodes. This paper propose Improved Soft-k-Means Clustering Charging Based on Node Collaborative Scheduling (ISKCC-NCS) to keep the coverage quality of WSN. At first, this algorithm uses Improved Soft-k-Means to cluster WRSN, and realizes confident information coverage through collaborative sensing between adjacent nodes. The second, we evaluate the coverage contribution of each node to be charged and calculate the priority of the node. The third, we form new charging path by inserting and deleting tasks. At last, a carrier charging vehicle (CCV) is used to carry several micro charging vehicle (MCV) to each cluster to charge the sensor node. Through a large number of simulation experiments, it is found that compared with other algorithms, ISKCC-NCS can significantly enhance the coverage rate and monitoring stability of the WSN.
期刊：
Renewable & Sustainable Energy Reviews,2022年165:112558 ISSN：1364-0321
通讯作者：
Chen, M.;Wang, M.
作者机构：
[Lin, Meng; Chen, Ming; Yu, Yang; Wang, Haijiang; Zou, Jiexin; Xing, Shuang; Zaman, Shahid] Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China.;[Zhao, Chen] Shenzhen Polytech, Res Inst New Energy Vehicle Technol, Shenzhen 518055, Peoples R China.;[Gong, Hongwei] CNOOC EnerTech Drilling & Prod Co, Shenzhen Branch, Shenzhen 518055, Peoples R China.;[Wang, Yajun] Univ South China, Sch Elect Engn, Hengyang 421200, Peoples R China.;[Wang, Min] China Univ Petr East China, Coll New Energy, Qingdao 266580, Peoples R China.
通讯机构：
[Ming Chen] D;[Min Wang] C;Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, China<&wdkj&>College of New Energy, China University of Petroleum (East China), Qingdao 266580, China
关键词：
Forced-convection;Fuel cell;Heat and water management;Open-cathode;Temperature
摘要：
Forced-convection open-cathode proton exchange membrane fuel cells (FCOC-PEMFCs) can directly use ambient air to supply oxygen and provide cooling without a complex air supply subsystem, have drawn tremendous attention. However, inefficient heat and water management are challenging in FCOC-PEMFCs. This paper aims to provide the general idea and current idea from component level to system level for the design of heat and water management of FCOC-PEMFCs. The water-heat-electric characteristics of FCOC-PEMFCs, the influence of operating conditions, the flow channel design at the single-cell level, the application of novel heat dissipation enhancement methods at the stack level, the design of the cooling subsystem, and temperature control strategy are deeply analyzed. Besides, the key findings, challenges, and future work are put forward. The future work mainly includes the enhancing the environmental adaptability and stability of the stack, avoiding flooding and dehydration, combining passive and active methods to enhance heat and water management ability, developing efficient temperature control strategies based on a large number of experimental data and machine learning technology, and diagnostic technology applicable for FCOC-PEMFC. The provided information is anticipated to accelerate the commercialization of portable fuel cells.
