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Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River

Journal of Ocean University of China 2024年第1期23卷 99-108页

作者： ZHANG Han BURNETT CWilliam ZHANG Xiaojie ZHAO Shibin YANG Disong NAN Haiming YU Zhigang XU Bochao Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of EducationOcean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahasseeFL 32306USA North China Sea Environmental Monitoring Center State Oceanic AdministrationKey Laboratory of Ecological Prewarning and Protection of Bohai SeaMNRQingdao 266033China Shandong Provincial Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266033China

Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and *** analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year *** showed that medium silt(16–32µm)was the main *** expected,the activity of each radionuclide decreased with an increase of particle *** examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different *** results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed *** high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream *** occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.

关键词： the Yellow River suspended particulate matter size-fractions radionuclides sediment sources water elutriator

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Soft ionic-hydrogel electrodes for electroencephalography signal recording

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Science China(Technological Sciences) 2021年第2期64卷 273-282页

作者： SHENG XinJun QIN Zhun XU HaiPeng SHU XiaoKang GU GuoYing ZHU XiangYang Robotics Institute School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Wet gel electrodes have been widely used for electroencephalography(EEG) signal recording, which generally causes skin abrasion and longer preparation time. In this paper, we present soft ionic-hydrogel based electrodes to overcome such *** order to conveniently measure the EEG signals, we design the claw-like and patch-like structures for robust connection between metal(Ag/Ag Cl) electrodes and skin scalps. Next, we experimentally show that the soft ionic-hydrogel based electrodes have similar performance with the conventional wet gel electrodes in terms of the short-circuit noise, electrical impedance, and skin-electrode contact impedance on unprepared human skin, significantly better than dry electrodes and water-based *** further perform the EEG measurements and steady-state visual evoked potentials(SSVEP) experiments with five subjects to verify the effectiveness of the soft ionic-hydrogel based electrodes. The experimental results demonstrate that our developed soft ionic-hydrogel electrodes can record high-quality EEG signals in a fast and clean way, being a compelling option for EEG-based brain-computer interfaces.

关键词： brain-computer interface EEG electrodes ionic hydrogel soft materials

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A Sensorless Speed Control of High-Speed BLDC Motor Using Variable Slope SMO

A Sensorless Speed Control of High-Speed BLDC Motor Using Va...

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作者： Ok, Sangjae Xu, Zhenyao Lee, Dong-Hee Department of Mechatronics Engineering Kyungsung University Busan48434 Korea Republic of State Key Laboratory of Robotics Shenyang Institute of Automation The Chinese Academy of Sciences Shenyang110016 China

Low-power and high-speed BLDC(Brushless DC) motor is widely used in vacuum cleaners. This paper presents a sensorless speed control scheme for a high-speed BLDC motor of a hand-stick vacuum cleaner using a variable slope sliding mode observer(SMO). The SMO using the signum function is very effective for the sensorless estimation of the BLDC motor. However, the chattering effect on the slide surface from the signum function decreases the sensorless performance in the wide speed range. The sigmoid function instead of the signum function can reduce the chattering effect. However, the convergence is inversely proportional to the reduced chattering effect. In order to reduce the chattering effect and keep the proper convergence performance, the proposed method uses a variable acceleration slope of the sigmoid function. In the low-speed range, the acceleration slope of SMO is decreased to reduce the chattering. And, it is increased to improve the convergence in the high-speed region. The acceleration slope of the sigmoid function is designed as a function of the estimated speed to keep the constant convergence with reduced chattering in the sensorless speed and position estimation. In order to verify the proposed sensorless control scheme, 115 krpm speed 540W BLDC motor for a vacuum cleaner is tested with various SMO methods. In the experimental results, the proposed method shows better sensorless speed control performance in the wide speed range. © 2023 IEEE.

关键词： Sensorless control

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ATTENTION-AWARE LAPAROSCOPIC IMAGE DESMOKING NETWORK WITH LIGHTNESS EMBEDDING AND HYBRID GUIDED EMBEDDING

arXiv

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arXiv 2024年

作者： Liu, Ziteng Zhu, Jiahua Liu, Bainan Liu, Hao Gao, Wenpeng Fu, Yili School of Life Science and Technology Harbin Institute of Technology Harbin150080 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150080 China State Key Laboratory of Robotics Shenyang Institute of Automation Shenyang110016 China

This paper presents a novel method of smoke removal from the laparoscopic images. Due to the heterogeneous nature of surgical smoke, a two-stage network is proposed to estimate the smoke distribution and reconstruct a clear, smoke-free surgical scene. The utilization of the lightness channel plays a pivotal role in providing vital information pertaining to smoke density. The reconstruction of smoke-free image is guided by a hybrid embedding, which combines the estimated smoke mask with the initial image. Experimental results demonstrate that the proposed method boasts a Peak Signal to Noise Ratio that is 2.79% higher than the state-of-the-art methods, while also exhibits a remarkable 38.2% reduction in run-time. Overall, the proposed method offers comparable or even superior performance in terms of both smoke removal quality and computational efficiency when compared to existing state-of-the-art methods. This work will be publicly available on http://***/wpgao. Copyright © 2024, The Authors. All rights reserved.

关键词： Smoke

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SoSpider:A bio-inspired multimodal untethered soft hexapod robot for planetary lava tube exploration

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Science China(Technological Sciences) 2023年第11期66卷 3090-3106页

作者： NIU LiZhou DING Liang ZHANG ShengJie YANG HuaiGuang GAO HaiBo DENG ZongQuan LIU GuangJun HOSSAIN Mokarram State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150001China Department of Aerospace Engineering Ryerson UniversityToronto ON M5B 2K3Canada Zienkiewicz Institute for Modelling Data and AISwansea UniversitySwansea SA18ENUnited Kingdom

Soft robots have tremendous potential for applications in various fields,owing to their safety and flexibility embedded at the material *** robots,especially bio-inspired soft legged robots,have become one of the most active fields of current research in robotics thanks to their superior mobility and ability to face complex ***,it is arduous to establish a dynamic simulation model for soft robots,owing to their hyper-redundant degrees of freedom,hyper-elasticity,and nonlinearity of their soft *** this study,we designed,simulated,and fabricated a hexapod robot that achieves walking,crawling,pronking,and rolling with wheeled legs plus a soft body capable of shape change.A robot prototype was fabricated using 3D printing technology and soft silicone pneumatic ***,battery power,and control boards were integrated into the body of the robot for untethered *** have explored the capabilities of the robot in different conditions,especially in scenarios that simulate lunar and Martian environments,demonstrating the motion performance of the *** results have shown promising potentials of the developed robot for future applications in planetary lava tube *** experimental and simulation results also show good agreements that indicate the potential predictive roles of simulation tools for soft robot design,planning,and control.

关键词： multimodal soft robot pneumatic simulation planetary exploration

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CASKA-CRT: Chinese Remainder Theorem Empowered Certificateless Aggregate Signcryption Scheme with key Agreement in IoVs

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-16页

作者： Hou, Yingzhe Cao, Yue Xiong, Hu Sun, Zhili Mumtaz, Shahid Tian, Daxin School of Cyber Science and Engineering Wuhan University Wuhan China School of Information and Software Engineering University of Electronic Science and Technology of China Chengdu China Institute of Communication Systems University of Surrey Guildford U.K Department of Applied Informatics Silesian University of Technology Akademicka Gliwice Poland State Key Laboratory of Vehicle-Infrastructure Integrated ITS the State Key Laboratory of Intelligent Transportation System and the School of Transportation Science and Engineering Beihang University Beijing China

To enhance the privacy of messages in Internet of Vehicles (IoVs), it is critical to preserve the communication security between Road Side Unit (RSU) and numerous vehicles. The primitive of signcryption is introduced to guarantee the confidentiality, integrity and unforgeability of transmitted messages. Nevertheless, the existing signcryption schemes fail to achieve a balance between security and efficiency. In this paper, we construct a Chinese remainder theorem (CRT) empowered certificateless aggregate signcryption scheme with key agreement (CASKA-CRT). As the vehicle joins and leaves dynamically, the proposed scheme can ensure the dynamic security via one modulo division operation. Besides, the certificateless aggregate signcryption and key agreement mechanisms are embedded. The former idea can both address the certificate management and key escrow problems, while the latter technology can create authentication as a premise of secure communication. Based on this construction, the hash-to-group operation and bilinear pairing are avoided, to realize a faster verification with the increased number of messages. Moreover, the security of proposed scheme is proved under the random oracle model. Finally, the performance analysis demonstrates the advantage of CASKA-CRT in terms of security and reliability over related works. IEEE

关键词： Public key cryptography

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Design and Control of Continuous Jumping Gaits for Humanoid Robots Based on Motion Function and Reinforcement Learning

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Procedia Computer Science 2024年 250卷 51-57页

作者： Zida Zhao Shilong Sun Haodong Huang Qingbin Gao Wenfu Xu State Key Laboratory of Robotics and System (HIT) Harbin Institute of Technology Harbin Heilongjiang China School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen 518055 China

Continuous jumping of humanoid robots is a challenging problem that requires appropriate gait and force control for the robot to achieve. Reinforcement learning (RL) has been applied to the motion control of humanoid robots and has achieved significant progress. However, traditional RL control methods primarily rely on designing reward signals to generate human-like movements, and it requires developing complex reward signals for continuous jumping, resulting in limited actions and suboptimal jumping performance. To address this issue, we have designed motion functions for humanoid continuous jumping and incorporated them into the RL framework to obtain desired human-like continuous jumping actions. Furthermore, two different jumping gaits are designed to investigate the jumping effects produced by different jumping functions: bent-knee jumping (BJ) and straight-knee jumping (SJ). BJ is a typical jumping style where the legs flex during the jumping process to accumulate energy, enabling higher explosive power. SJ is more suitable for tasks requiring quick responses, as the legs remain upright during the jump, providing faster reaction speed. The performance in continuous jumping tasks has been evaluated by comparing the effects of training with different jumping functions. This research has particular guidance for improving the jumping ability of robots and enhancing the stability and efficiency of humanoid continuous jumping.

关键词： Continuous jumping gaits Humanoid robots Motion function Reinforcement learning

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Enhancing interaction performance of soft pneumatic-networks grippers by skeleton topology optimization

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Science China(Technological Sciences) 2021年第12期64卷 2709-2717页

作者： CHEN ShiTong WANG YuSheng LI DeChen CHEN FeiFei ZHU XiangYang Robotics Institute School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

The inherent compliance of soft materials imbues robots,generally referred to as soft robots,with particular advantages in producing adaptive and safe ***,the mainstream design paradigms of soft robots have been focused on pursuing large free motions only,usually at the expense of greatly decreased stiffness,leading to limited capability of withstanding external loads in interactive *** is a pressing need to incorporate the interaction specifications at the design stage to embody soft robots with not only proper deformability but equally importantly,considerable stiffness to perform complex tasks in practical ***,inspired by the dexterity of human hands,we propose a computational design framework for soft grippers with a focus on improving their interaction performance in power grasping or precision grasping *** design paradigm rests on attaching a relatively stiffer skeleton layer to the parametric pneumatic networks based actuator which is widely used due to the geometric advantage,and the skeleton layout is designed for customized interaction conditions by a level set based topology optimization *** expected,the optimized skeleton layouts exhibit specified structural features highly relevant to the predefined concentrated loads for precision grip or distributed loads for power grip,which physically implies the compromise between deformability and *** the interaction forces are difficult to measure in situ,we devise power and precision grasping scenarios and evaluate the critical actuation pressure of the object’s falling *** experiments qualitatively demonstrate the superiority of each specified *** work represents an initial step toward the rational design for interaction in soft robots.

关键词： soft robotics interaction grippers topology optimization

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Energy Stable Nodal DG Methods for Maxwell’s Equations of Mixed-Order Form in Nonlinear Optical Media

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Communications on Applied Mathematics and Computation 2024年第1期6卷 30-63页

作者： Maohui Lyu Vrushali A.Bokil Yingda Cheng Fengyan Li State Key Laboratory of Scientific and Engineering Computing(LSEC) Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing100190China Department of Mathematics College of ScienceOregon State UniversityCorvallisOR97331USA Department of Mathematics Michigan State UniversityEast LansingMI48824USA Department of Computational Mathematics Science and EngineeringMichigan State UniversityEast LansingMI48824USA Department of Mathematical Sciences Rensselaer Polytechnic InstituteTroyNY12180USA

In this work,we develop energy stable numerical methods to simulate electromagnetic waves propagating in optical media where the media responses include the linear Lorentz dispersion,the instantaneous nonlinear cubic Kerr response,and the nonlinear delayed Raman molecular vibrational *** the first-order PDE-ODE governing equations considered previously in Bokil et al.(J Comput Phys 350:420–452,2017)and Lyu et al.(J Sci Comput 89:1–42,2021),a model of mixed-order form is adopted here that consists of the first-order PDE part for Maxwell’s equations coupled with the second-order ODE part(i.e.,the auxiliary differential equations)modeling the linear and nonlinear dispersion in the *** main contribution is a new numerical strategy to treat the Kerr and Raman nonlinearities to achieve provable energy stability property within a second-order temporal discretization.A nodal discontinuous Galerkin(DG)method is further applied in space for efficiently handling nonlinear terms at the algebraic level,while preserving the energy stability and achieving high-order *** with d_(E)as the number of the components of the electric field,only a d_(E)×d_(E)nonlinear algebraic system needs to be solved at each interpolation node,and more importantly,all these small nonlinear systems are completely decoupled over one time step,rendering very high parallel *** evaluate the proposed schemes by comparing them with the methods in Bokil et al.(2017)and Lyu et al.(2021)(implemented in nodal form)regarding the accuracy,computational efficiency,and energy stability,by a parallel scalability study,and also through the simulations of the soliton-like wave propagation in one dimension,as well as the spatial-soliton propagation and two-beam interactions modeled by the two-dimensional transverse electric(TE)mode of the equations.

关键词： Maxwell’s equations Kerr and Raman Discontinuous Galerkin method Energy stability

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An artificial neural network chip based on two-dimensional semiconductor

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Science Bulletin 2022年第3期67卷 270-277页

作者： Shunli Ma Tianxiang Wu Xinyu Chen Yin Wang Hongwei Tang Yuting Yao Yan Wang Ziyang Zhu Jianan Deng Jing Wan Ye Lu Zhengzong Sun Zihan Xu Antoine Riaud Chenjian Wu David Wei Zhang Yang Chai Peng Zhou Junyan Ren Wenzhong Bao State Key Laboratory of ASIC and System School of MicroelectronicsFudan UniversityShanghai 200433China State Key Laboratory of ASIC and System School of Information Science and TechnologyFudan UniversityShanghai 200433China Shenzhen Sixcarbon Technology Shenzhen 518106China School of Electronic and Information Engineering Soochow UniversitySuzhou 215006China Department of Applied Physics The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Recently,research on two-dimensional(2D)semiconductors has begun to translate from the fundamen-tal investigation into rudimentary functional *** this work,we unveil the first functional MoS2 artificial neural network(ANN)chip,including multiply-and-accumulate(MAC),memory and activation function *** MoS2 ANN chip is realized through fabricating 818 field-effect transistors(FETs)on a wafer-scale and high-homogeneity MoS2 film,with a gate-last process to realize top gate structured FETs.A 62-level simulation program with integrated circuit emphasis(SPICE)model is utilized to design and optimize our analog ANN *** demonstrate a practical application,a tactile digit sensing recognition was demonstrated based on our ANN *** training,the digit recognition rate exceeds 97%.Our work not only demonstrates the protentional of 2D semiconductors in wafer-scale inte-grated circuits,but also paves the way for its future application in AI computation.

关键词： MoS_(2) Two-dimensional(2D)FETs Artificial neural network(ANN) Multiply-and-accumulate(MAC) Circuits

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