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Adaptive Handover Decision Inspired By Biological Mechanism in Vehicle Ad-hoc Networks

Computers, Materials & Continua 2019年第9期61卷 1117-1128页

作者： Xuting Duan Jingyi Wei Daxin Tian Jianshan Zhou Haiying Xia Xin Li Kunxian Zheng Beijing Advanced Innovation Center for Big Data and Brain Computing Beijing100191China Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems&SafetyControl Beijing100191China School of Transportation Science and Engineering Beihang UniversityBeijing100191China Department of Engineering and Design University of SussexBrightonBN19RHUK Research Institute of Highway Ministry Transport Beijing100088China Department of Computer Science and Technology Tsinghua UniversityHaidian DistrictBeijing100088China

In vehicle ad-hoc networks(VANETs),the proliferation of wireless communication will give rise to the heterogeneous access environment where network selection becomes *** by the self-adaptive paradigm of cellular attractors,this paper regards an individual communication as a cell,so that we can apply the revised attractor selection model to induce each connected *** at improving the Quality of Service(QoS),we presented the bio-inspired handover decision-making *** addition,we employ the Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS)for any vehicle to choose an access *** paper proposes a novel framework where the bio-inspired mechanism is combined with *** a dynamic and random mobility environment,our method achieves the coordination of performance of heterogeneous networks by guaranteeing the efficient utilization and fair distribution of network resources in a global *** experimental results confirm that the proposed method performs better when compared with conventional schemes.

关键词： Revised attraction selection model TOPSIS VANETs QoS

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Multispectral airborne laser scanning point-clouds for land cover classification using convolutional neural networks 4

Multispectral airborne laser scanning point-clouds for land ...

引用

4th ISPRS Geospatial Week 2019

作者： Ma, L. Chen, Z. Li, Y. Zhang, D. Li, J. Chapman, M.A. Department of Geography and Environmental Management University of Waterloo WaterlooONN2L 3G1 Canada Department of Systems Design Engineering University of Waterloo WaterlooONN2L 3G1 Canada Fujian Key Laboratory of Sensing and Computing for Smart Cities School of Information Science and Engineering Xiamen University Xiamen Fujian361005 China Department of Civil Engineering Ryerson University TorontoONM5B 2K3 Canada

This paper presents an automated workflow for pixel-wise land cover (LC) classification from multispectral airborne laser scanning (ALS) data using deep learning methods. It mainly contains three procedures: data pre-processing, land cover classification, and accuracy assessment. First, a total of nine raster images with different information were generated from the pre-processed point clouds. These images were assembled into six input data combinations. Meanwhile, the labelled dataset was created using the orthophotos as the ground truth. Also, three deep learning networks were established. Then, each input data combination was used to train and validate each network, which developed eighteen LC classification models with different parameters to predict LC types for pixels. Finally, accuracy assessments and comparisons were done for the eighteen classification results to determine an optimal scheme. The proposed method was tested on six input datasets with three deep learning classification networks (i.e., 1D CNN, 2D CNN, and 3D CNN). The highest overall classification accuracy of 97.2% has been achieved using the proposed 3D CNN. The overall accuracy (OA) of the 2D and 3D CNNs was, on average, 8.4% higher than that of the 1D CNN. Although the OA of the 2D CNN was at most 0.3% lower than that of the 3D CNN, the runtime of the 3D CNN was five times longer than the 2D CNN. Thus, the 2D CNN was the best choice for the multispectral ALS LC classification when considering efficiency. The results demonstrated the proposed methods can successfully classify land covers from multispectral ALS data. © Authors 2019.

关键词： Data handling

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Discovery of a maximally charged Weyl point

arXiv

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arXiv 2022年

作者： Chen, Qiaolu Chen, Fujia Yan, Qinghui Zhang, Li Gao, Zhen Yang, Shengyuan A. Yu, Zhi-Ming Chen, Hongsheng Zhang, Baile Yang, Yihao Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang University Hangzhou310027 China International Joint Innovation Center Key Lab. of Advanced Micro Nano Electronic Devices & Smart Systems of Zhejiang The Electromagnetics Academy Zhejiang University Zhejiang University Haining314400 China Jinhua Institute of Zhejiang University Zhejiang University Jinhua321099 China Department of Electrical and Electronic Engineering Southern University of Science and Technology Shenzhen518055 China Research Laboratory for Quantum Materials Singapore University of Technology and Design 487372 Singapore School of Physics Beijing Institute of Technology Beijing100081 China Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems School of Physics Beijing Institute of Technology Beijing100081 China Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link 637371 Singapore Centre for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University 50 Nanyang Avenue 639798 Singapore

The hypothetical Weyl particles in high-energy physics have been discovered in three-dimensional crystals as collective quasiparticle excitations near two-fold degenerate Weyl points1-5. Such momentum-space Weyl particles carry quantized chiral charges, which can be measured by counting the number of Fermi arcs emanating from the corresponding Weyl points. It is known that merging unit-charged Weyl particles can create new ones with more charges6. However, only very recently has it been realised that there is an upper limit - the maximal charge number that a two-fold Weyl point can host is four - achievable only in crystals without spin-orbit coupling7-9. Here, we report the experimental realisation of such a maximally charged Weyl point in a three-dimensional photonic crystal. The four charges support quadruple-helicoid Fermi arcs, forming an unprecedented topology of two non-contractible loops in the surface Brillouin zone. The helicoid Fermi arcs also exhibit the long-pursued type-II van Hove singularities that can reside at arbitrary momenta. This discovery reveals a type of maximally charged Weyl particles beyond conventional topological particles in crystals. Copyright © 2022, The Authors. All rights reserved.

关键词： Topology

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SLAM-BASED MULTI-SENSOR BACKPACK LIDAR systems IN GNSS-DENIED ENVIRONMENTS

SLAM-BASED MULTI-SENSOR BACKPACK LIDAR SYSTEMS IN GNSS-DENIE...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Dedong Zhang Zheng Gong Yiping Chen John Zelek Jonathan Li Department of Geography and Environmental Management University of Waterloo Waterloo Canada Department of Systems Design Engineering University of Waterloo Waterloo Canada Fujian Key Laboratory of Sensing and Computing for Smart Cities Xiamen University Xiamen China

The backpack LiDAR system is a highly efficient device for indoor positioning and navigation. With the use of multi-sensor interactions inside of the backpack, it can solve the problem of undetermined trajectories or locations in a GNSS-denied environment. This paper presents a multi-sensor-based backpack LiDAR system for mapping in GNSS-denied environments. With this device, we solve the problem of inaccurate positioning caused by the inability to receive GNSS signals in a small-sized lidar portable device, also reduces the cumulative error caused by the IMU module through the analysis of the vibration pattern. Through the demonstration of the results, the method is of great significance for 3D reconstruction of the indoor environment and object detection.

关键词： Laser radar Three-dimensional displays Vibrations Acceleration Legged locomotion Wavelet transforms Global navigation satellite system

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Mechanical Analysis and Performance Optimization for the Lunar Rover’s Vane-Telescopic Walking Wheel

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engineering 2020年第8期6卷 936-943页

作者： Lu Yang Bowen Cai Ronghui Zhang Kening Li Zixian Zhang Jiehao Lei Baichao Chen Rongben Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Guangdong Key Laboratory of Intelligent Transportation System School of Intelligent Systems EngineeringSun Yat-sen UniversityGuangzhou 510275China College of Transportation Jilin UniversityChangchun 130025China Department of Mechanical Science and Engineering Tokyo Institute of TechnologyTokyo 152-8550Japan Armour College of Engineering Illinois Institute of TechnologyChicagoIL 60616USA China Academy of Space Technology Beijing 100029China

It is well-known that optimizing the wheel system of lunar rovers is ***,this is a difficult task due to the complex terrain of the moon and limited resources onboard lunar *** this study,an experimental prototype was set up to analyze the existing mechanical design of a lunar rover and improve its ***,a new vane-telescopic walking wheel was proposed for the lunar rover with a positive and negative quadrangle suspension,considering the complex terrain of the ***,the performance was optimized under the limitations of preserving the slope passage and minimizing power *** was achieved via analysis of the wheel force during ***,the effectiveness of the proposed method was demonstrated by several simulation *** newly designed wheel can protrude on demand and reduce energy consumption;it can be used as a reference for lunar rover development engineering in China.

关键词： Intelligent vehicle Vane-telescopic walking wheel Performance optimization Vane spring Lunar rover

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Higher-order nodal points in two dimensions

arXiv

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arXiv 2021年

作者： Wu, Weikang Liu, Ying Yu, Zhi-Ming Zhao, Y.X. Gao, Weibo Yang, Shengyuan A. Research Laboratory for Quantum Materials Singapore University of Technology and Design Singapore487372 Singapore Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore School of Materials Science and Engineering Hebei University of Technology Tianjin300130 China Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems School of Physics Beijing Institute of Technology Beijing100081 China National Laboratory of Solid State Microstructures Department of Physics Nanjing University Nanjing210093 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210093 China

A two-dimensional (2D) topological semimetal is characterized by the nodal points in its low-energy band structure. While the linear nodal points have been extensively studied, especially in the context of graphene, the realm beyond linear nodal points remains largely unexplored. Here, we explore the possibility of higher-order nodal points, i.e., points with higher-order energy dispersions, in 2D systems. We perform an exhaustive search over all 80 layer groups both with and without spin-orbit coupling (SOC), and reveal all possible higher-order nodal points. We show that they can be classified into two categories: the quadratic nodal point (QNP) and the cubic nodal point (CNP). All the 2D higher-order nodal points have twofold degeneracy, and the order of dispersion cannot be higher than three. QNPs only exist in the absence of SOC, whereas CNPs only exist in the presence of SOC. Particularly, the CNPs represent a new topological state not known before. We show that they feature nontrivial topological charges, leading to extensive topological edge bands. Our work completely settles the problem of higher-order nodal points, discovers novel topological states in 2D, and provides detailed guidance to realize these states. Possible material candidates and experimental signatures are discussed. Copyright © 2021, The Authors. All rights reserved.

关键词： Dispersions

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design of A Multi-Functional Soft Ankle Exoskeleton for Foot-Drop Prevention, Propulsion Assistance, and Inversion/Eversion Stabilization

Design of A Multi-Functional Soft Ankle Exoskeleton for Foot...

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IEEE/RAS-EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob)

作者： Haisheng Xia Junghan Kwon Prabhat Pathak Jooeun Ahn Peter B. Shull Yong-Lae Park State Key Laboratory of Mechanical Systems and Vibration School of Mechanical Engineering Shanghai Jiao Tong University Shanghai China Department of Mechanical Engineering Soft Robotics Research Center (SRRC) the Institute of Advanced Machines and Design (IAMD) Seoul National University Seoul South Korea Department of Physical Education Seoul National University Seoul South Korea

ISBN: (数字)9781728159072

ISBN: (纸本)9781728159089

Stroke often results in hemiplegia, which greatly affects the walking ability of the patients. We propose a multi-functional portable ankle exoskeleton for use in preventing foot-drops, assisting propulsion, and stabilizing inversion/eversion during walking to help gait rehabilitation of stroke patients. The portable ankle exoskeleton was fabricated by 3D printing a soft/rigid hybrid structure. The device was able to prevent foot-drop and assist propulsion with a bi-directional cable-driven actuation system. It also showed a capability of stabilizing inversion/eversion motions using a counter-electromotive force of two small, lightweight gear motors. The device was controlled by a microcontroller based on real-time feedback from one inertial measurement unit and a customized force sensitive resistor. The device is fully untethered with all the components integrated on-board, with a total weight of less than 1 kg. Five healthy subjects performed over-ground walking tests with the proposed ankle exoskeleton for three different walking situations (normal walking, walking with simulated foot-drop, and walking on an uneven terrain) and three walking conditions (without the exoskeleton, with the exoskeleton powered off, and with the exoskeleton powered on). From the test results, we confirmed the feasibility of the proposed ankle exoskeleton for foot-drop prevention, propulsion assistance, and inversion/eversion stabilization. The ankle exoskeleton showed a potential for wearable gait rehabilitation for stroke patients with high mobility and portability.

关键词： Legged locomotion Exoskeletons Propulsion Robots DC motors Stroke (medical condition) Connectors

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Potential Function Based Fully Distributed Finite-Time Event-Triggered Consensus for Multi-Agent systems over Directed Graphs

Potential Function Based Fully Distributed Finite-Time Event...

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IEEE Conference on Decision and Control

作者： Changkun Du Haikuo Liu Yougang Bian Changbin Yu Beijing Advanced Innovation Center for Intelligent Robots and Systems School of Mechatronical Engineering Beijing Institute of Technology Beijing China School of Mechatronical Engineering Beijing Institute of Technology Beijing China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University Changsha China Optus-Curtin Center of Excellence in Artificial Intelligence Curtin University Perth WA Australia

ISBN: (数字)9781728174471

ISBN: (纸本)9781728174488

This paper proposes a novel approach for distributed finite-time event-triggered consensus control of multi-agent systems over directed graphs. In the proposed approach, a potential function is introduced in the control protocol design and a dynamic external variable with a finite-time convergence rate is involved in the construction of triggering thresholds. By using the proposed approach, finite-time consensus can be achieved in a fully distributed manner and the Zeno behavior is ruled out in the framework of finite-time event-triggered consensus. The proposed approach does not need global information and only a directed spanning tree is required for the underlying communication graph. Additionally, the requirement on continuous communication for controller updates or triggering detection is removed. Finally, an example is given to show the feasibility of the proposed approach.

关键词： Symmetric matrices Directed graphs Convergence Vehicle dynamics Protocols Linear matrix inequalities Two dimensional displays

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Description of collective magnetization processes with machine learning models

arXiv

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arXiv 2022年

作者： Kornell, Alexander Exl, Lukas Breth, Leoni Fischbacher, Johann Kovacs, Alexander Oezelt, Harald Gusenbauer, Markus Yano, Masao Sakuma, Noritsugu Kinoshita, Akihito Shoji, Tetsuya Kato, Akira Mauser, Norbert J. Schrefl, Thomas Christian Doppler Laboratory for Magnet Design Through Physics Informed Machine Learning Viktor Kaplan-Straße 2E Wiener Neustadt2700 Austria Department for Integrated Sensor Systems Danube University Krems Viktor Kaplan-Straße 2E Wiener Neustadt2700 Austria Research Platform MMM Mathematics-Magnetism-Materials c/o Fak. Mathematik University of Vienna Oskar-Morgenstern-Platz 1 Vienna1090 Austria Wolfgang Pauli Institute c/o Fak. Mathematik University of Vienna Oskar-Morgenstern-Platz 1 Vienna1090 Austria Advanced Materials Engineering Div. Toyota Motor Corporation 1200 Mishuku Susono Shizuoka410-1193 Japan

This work introduces a latent space method to calculate the demagnetization reversal process of multigrain permanent magnets. The algorithm consists of two deep learning models based on neural networks. The embedded Stoner-Wohlfarth method is used as a reduced order model for computing samples to train and test the machine learning approach. The work is a proof of concept of the method since the used microstructures are simple and the only varying parameters are the magnetic anisotropy axes of the hard magnetic grains. A convolutional autoencoder is used for nonlinear dimensionality reduction, in order to reduce the required amount of training samples for predicting the hysteresis loops. We enriched the loss function with physical information about the underlying problem which increases the accuracy of the machine learning approach. A deep learning regressor is operating in the latent space of the autoencoder. The predictor takes a series of previously encoded magnetization states and outputs the next magnetization state along the hysteresis curve. To predict the complete demagnetization loop, we apply a recursive learning scheme. © 2022, CC BY.

关键词： Demagnetization

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EEG microstates: Functional significance and short-term test-retest reliability

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Neuroimage: Reports 2022年第2期2卷 100089-100089页

作者： Antonova, Elena Holding, Martin Suen, Ho Chak Sumich, Alex Maex, Reinoud Nehaniv, Chrystopher Division of Psychology Department of Life Sciences College of Health Medicine and Life Sciences & Centre for Cognitive Neuroscience Brunel University London Kingston Lane Uxbridge UB8 3PH United Kingdom Department of Psychology Institute of Psychiatry Psychology & Neuroscience King's College London De Crespigny Park London SE5 8AF United Kingdom Department of Psychology School of Social Sciences Nottingham Trent University 50 Shakespeare Street Nottingham NG1 4FQ United Kingdom Royal Society Wolfson Biocomputation Research Laboratory Centre for Computer Science and Informatics Research University of Hertfordshire College Lane Hatfield AL10 9AB United Kingdom Departments of Systems Design Engineering and Electrical & Computer Engineering University of Waterloo 200 University Avenue W Waterloo N2L 3G1 ON Canada

EEG microstates, reflecting discrete topographical organization of the EEG signal power, may have clinical relevance;however, their functional significance and test-retest reliability remain unclear. To investigate the functional significance of the canonical EEG microstate classes and their pairwise transitions, and to establish their within-session test-retest reliability, we recorded 36-channel EEGs in 20 healthy volunteers during three eyes-closed conditions: mind-wandering, verbalization (silently repeating the word ‘square’ every 2 s), and visualization (visualizing a square every 2 s). Each condition lasted 3 min and the sequence of three conditions was repeated four times (two runs of two sequence repetitions). The participants' alertness and their sense of effort during the experiment were rated using visual-analogue scales. The EEG data were 2–20 Hz bandpass-filtered and analysed into the four canonical microstate classes: A, B, C, and D. EEG microstate classes C and D were persistently more dominant than classes A and B in all conditions. Of the first-order microstate parameters, average microstate duration was most reliable. The duration of class D microstate was longer during mind-wandering (106.8 ms) than verbalization (102.2 ms) or visualization (99.8 ms), with a concomitantly higher coverage (36.4% vs. 34.7% and 35.2%), but otherwise there was no clear association of the four microstate classes to particular mental states. The test-retest reliability was higher at the beginning of each run, together with higher average alpha power and subjective ratings of alertness. Only the transitions between classes C and D (from C to D in particular) were significantly higher than what would be expected from the respective microstates' occurrences. The transition probabilities, however, did not distinguish between conditions, and their test-retest reliability was overall lower than that of the first-order parameters such as duration and coverage. Further studies

关键词： Biomarkers EEG microstates Mind-wandering Neuroimaging Resting-state EEG Resting-state networks

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