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arXiv 2021年

作者： Gao, Xiangyu Li, Jianzhong Miao, Dongjing Department of Computer Science and Technology Harbin Institute of Technology Harbin China Faculty of Computer Science and Control Engineering Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

With the rapid popularization of big data, the dichotomy between tractable and intractable problems in big data computing has been shifted. Sublinear time, rather than polynomial time, has recently been regarded as the new standard of tractability in big data computing. This change brings the demand for new methodologies in computational complexity theory in the context of big data. Based on the prior work for sublinear-time complexity classes [9], this paper focuses on sublineartime reductions specialized for problems in big data computing. First, the pseudo-sublinear-time reduction is proposed and the complexity classes P and PsT are proved to be closed under it. To establish PsT-intractability for certain problems in P, we find the first problem in P \ PsT. Using the pseudo-sublinear-time reduction, we prove that the nearest edge query is in PsT but the algebraic equation root problem is not. Then, the pseudopolylog-time reduction is introduced and the complexity class PsPL is proved to be closed under it. The PsT-completeness under it is regarded as an evidence that some problems can not be solved in polylogarithmic time after a polynomial-time preprocessing, unless PsT = PsPL. We prove that all PsT-complete problems are also P-complete, which gives a further direction for identifying PsT-complete problems. Copyright © 2021, The Authors. All rights reserved.

关键词： Big data

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Bi-Directional Human-Robot Handover Using a Novel Supernumerary Robotic System

Bi-Directional Human-Robot Handover Using a Novel Supernumer...

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IEEE Workshop on Advanced Robotics and its Social Impacts, ARSO

作者： Yuwei Du Xin Zhang Mattia Leonori Pietro Balatti Jing Jin Qiang Wang Arash Ajoudani Department of Control Science and Engineering School of Astronautics Harbin Institute of Technology Heilongjiang China Human-Robot Interfaces and Interaction (HRI2) Lab Istituto Italiano di Tecnologia Genova Italy State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang China

Cooperative human-robot systems are the key technology to improve efficiency in agile production. In this work, a novel on-shoulder supernumerary robotic limb (SRL) is developed for human-robot collaboration. The SRL system is mainly composed of a 6-degree-of-freedom (DoF) lightweight robotic arm and a wearable and adjustable base, which allows different users to regulate the arm installation position to fit their physical dimensions and expand their workspace. As the SRL is close to the human head, nullspace-based collision avoidance is designed to achieve safe motion planning. Meanwhile, a Kalman filter is designed to actively predict human hand position and yield anticipatory motion control of our SRL in handover tasks. Furthermore, we conduct a bi-directional handover case study to verify the capability of the SRL system and the effectiveness of the proposed collaborative handover. The result shows that our control method can guarantee intuitive and natural handover behavior.

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An Optimization Method for Multi-loop Transient Performance Suitable for Multi-module Expansion

An Optimization Method for Multi-loop Transient Performance ...

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International Conference on Electrical Machines and Systems (ICEMS)

作者： Yi Zhang Donglai Zhang Yunhan Fan Qian Wan Qing Liu Shaolin Wang Power Electronics and Motion Control Research Center Harbin Institute of Technology (Shenzhen) Shenzhen China Unit 61655 the People’s Liberation Army Chongqing China Department of Aerospace Power Shenzhen Aerospace New Power Technology Co. Ltd Shenzhen China Beijing institute of Spacecraft System Engineering China Academy of Space Technology Beijing China

With the increase of power utilization rate of renewable energy systems and the profound studies of DC microgrids, DC distribution systems are getting more attention. To improve the quality of DC bus, it is necessary to consider the voltage fluctuations caused by loop switching such as battery management and maximum power output in the system. An optimization method is proposed to accelerate the switching process of multiple control loops, especially for multi-module expansion, which can improve the performance of dynamic response The proposed method just requires the addition of a few devices to the circuit structure and realizes nonlinear control, with which the conditional intervention only happens during transient processes without affecting the steady-state loop design. Compared with traditional methods, this method can achieve power expansion of the system as well as a quick response under load step or bus voltage overshoot.

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Fuzzy-Model-Based Robust control of Markov Jump Nonlinear Systems With Incomplete Transition Probabilities and Uncertain Packet Dropouts

Research Square

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Research Square 2021年

作者： Xu, Zeyuan Er, Meng Joo Department of Control Science and Engineering Harbin Institute of Technology Harbin150001 China School of Marine Electrical Engineering Dalian Maritime University Dalian116026 China

Interval type-2 fuzzy Markov jump systems (IT2FMJSs) have received much attention because they can better describe complex nonlinear systems with uncertainties and stochastic system mode switching. Over the past decade, many excellent results of fuzzy MJSs (FMJSs) have been reported. However, the transition probabilities which govern the dynamic behaviour of MJSs have been assumed to be completely known, limiting real-world applications of existing results. Different from the previous studies, transition probabilities between system modes switching are partly unknown, and packet dropouts of data transmission are uncertain in this study. The main contributions of this work are: (1) To analyze stochastic stability and reduce conservatism, a novel Lyapunov function which both depends on system mode and fuzzy basis function is constructed;(2) The existence of a mode-dependent and fuzzy-basis-dependent state-feedback controller is investigated;(3) The closed-loop system is stochastically stable with a desired H∞ performance, thereby addressing the problem of incomplete transition probabilities and uncertain packet dropouts. An illustrative example of a robot arm is used to demonstrate the effectiveness and practicality of the proposed approach. By virtue of the proposed approach, the effects of incomplete transition probabilities and uncertain packet dropouts on IT2FMJSs are alleviated. © 2021, CC BY.

关键词： Stochastic systems

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Spectral asymmetry effect in terahertz generation by two-color ionizing femtosecond pulses

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Physical Review A 2025年第2期111卷 023508-023508页

作者： Zhiwen Zhang Vasily A. Kostin Alexander A. Silaev Zefu Liu Shixiang Wang Chenhui Lu Zhengquan Fan Yi Liu Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology Shanghai 200093 China Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences Nizhny Novgorod 603950 Russia Department of Control Theory Lobachevsky State University of Nizhny Novgorod Nizhny Novgorod 603022 Russia Department of Electrodynamics Lobachevsky State University of Nizhny Novgorod Nizhny Novgorod 603022 Russia School of Mechanical and Automotive Engineering Shanghai University of Engineering Science Shanghai 201620 China CAS Center for Excellence in Ultra-Intense Laser Science Shanghai 201800 China

Ultrabroadband intense terahertz (THz) radiation generated by two-color femtosecond pulses is a promising tool for applications in many areas involving linear and nonlinear terahertz spectroscopy and light-matter interactions. The essential challenge is to understand and control the THz spectrum in order to optimize it for specific applications. Here we study the frequency-dependent modulation of the THz spectrum with the relative phase between the second-harmonic and fundamental-field components of the linearly polarized femtosecond pulse. Analytical consideration reveals the physical reason for the suppression of the spectral modulation, which is local (induced by the local ionization dynamics and electron motion and not related to propagation effects such as phase slippage) and coherent (associated only with the phase-dependent coherent THz waveforms). The spectral modulation is sensitive to the frequency detuning, both its absolute value and the sign. Having this asymmetric dependence on the detuning, the suppressed modulation can be observed even in commensurate two-color pulses with the effect enhanced additionally by the ionization blueshift. The theoretical findings are confirmed by the experiment, where we employed chirped two-color pulses with a variable time delay between their components, effectively enabling a scan over the detuning. The obtained results show that not only the THz yield but also the spectral shape can be effectively controlled by the relative phase and may be very sensitive to a small frequency detuning arising naturally during two-color pulse propagation.

关键词： Terahertz spectroscopy

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A Small-Gain Approach for Three-Dimensional Integrated Guidance and control in Pursuit-Evasion Games

A Small-Gain Approach for Three-Dimensional Integrated Guida...

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第32届中国控制与决策会议

作者： Han Yan Mingzhe Hou Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control Engineering Center for Control Theory and Guidance Technology Harbin Institute of Technology

A three-dimensional（3 D） integrated guidance and control（IGC） design approach for pursuit-evasion game is proposed by using small-gain theorem in this *** 3 D IGC model is formulated by combining nonlinear pursuer（missile） dynamics with nonlinear dynamics describing pursuit-evasion ***-gain theorem and input-to-state stability（ISS） theory are iteratively utilized to design virtual controls（desired attack angle,sideslip angle and attitude angular rates）,and eventually an IGC law is *** is proven that,with the proposed IGC law,the stability of the overall system can be guaranteed,and the line-of-sight（LOS） rate converges into a small neighborhood of zero as *** algorithm is also tested by using computer simulations against a maneuvering evader.

关键词： Integrated guidance and control Small-gain theorem Input-to-state stability Robustness

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3D visual tracking framework with deep learning for asteroid exploration

arXiv

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arXiv 2021年

作者： Zhou, Dong Sun, Guanghui Hong, Xiaopeng The Department of Control Science and Engineering Harbin Institute of Technology Harbin150001 China The Faculty of Electronic and Information Engineering Xi'an Jiaotong University Xi'an710049 China

3D visual tracking is significant to deep space exploration programs, which can guarantee spacecraft to flexibly approach the target. In this paper, we focus on the studied accurate and real-time method for 3D tracking. Considering the fact that there are almost no public dataset for this topic, A new large-scale 3D asteroid tracking dataset is presented, including binocular video sequences, depth maps, and point clouds of diverse asteroids with various shapes and textures. Benefitting from the power and convenience of simulation platform, all the 2D and 3D annotations are automatically generated. Meanwhile, we propose a deep-learning based 3D tracking framework, named as Track3D, which involves 2D monocular tracker and a novel light-weight amodal axis-aligned bounding-box network, A3BoxNet. The evaluation results demonstrate that Track3D achieves state-of-the-art 3D tracking performance in both accuracy and precision, comparing to a baseline algorithm. Moreover, our framework has great generalization ability to 2D monocular tracking performance. © 2021, CC BY-NC-SA.

关键词： Asteroids

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Adaptive Faster Fixed-Time Nonsingular Terminal Sliding Mode control for Manipulator Systems

Adaptive Faster Fixed-Time Nonsingular Terminal Sliding Mode...

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Chinese Automation Congress (CAC)

作者： Kunpeng Zhang Zhuang Liu Ruiqi Xu Dongling Yu Deshan Kong Qichao Guan Yue Zhao Yichun Power Supply Company State Grid Heilongjiang Electric Power Company Limited Yichun P. R. China Department of Control Science and Engineering Harbin Institute of Technology Harbin P. R. China

In this paper, a controller which can achieve fixed-time convergence is studied for manipulator systems. Firstly, an adaptive neural network (ANN) is used to estimate the unknown parts and external disturbances of the system. Secondly, a piecewise sliding mode variable is used to realize the nonsingular control of the terminal sliding mode. Then, in order to improve the tracking speed of the manipulator system, a faster fixed-time control algorithm is designed, and the tracking error can converge within a faster fixed-time. Finally, the practicability of the proposed algorithm is verified by simulation.

关键词： Adaptation models Uncertainty Adaptive systems Automation Simulation Neural networks Manipulators

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Fast Single Tracking Location Shear Wave Elasticity Imaging

Fast Single Tracking Location Shear Wave Elasticity Imaging

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IEEE Instrumentation and Measurement technology Conference

作者： Yang Xiao Jing Jin Yue Zhao Yu Yuan Yi Shen Naizhang Feng Control Theory and Engineering Harbin Institute of Technology Harbin P.R. China

ISBN: (数字)9781728144603

ISBN: (纸本)9781728144610

Single tracking location shear wave elasticity imaging (STL-SWEI) has been proven to have the capability to eliminate the speckle bias due to its unique push-tracking mode. However, compared to multiple tracking location shear wave elasticity imaging (MTL-SWEI), STL-SWEI requires more acoustic excitation and push-track sequences, and thus has a lower frame rate. In this work, a new approach named fast single tracking location shear wave elasticity imaging (FSTL-SWEI) is presented. FSTL utilizes spatially modulated ultrasound radiation force (SMURF) applying a special acoustic intensity pattern to generate lateral sinusoidal distributed (LSD) shear waves. It infers shear wave speed (SWS) distribution using the instantaneous phase of the shear wave motion signals obtained by the Hilbert-Huang Transform. Able to map the elasticity of the region of interest (ROI) in only one push-track sequence, it can achieve a frame rate comparative to MTL-SWEI. To validate the performance of this method, a finite element model (FEM) was established to simulate breast tissue with an inclusion. The simulation results show that FSTL can well distinguish the inclusion from the background.

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Cellulose-based materials in environmental protection: A scientometric and visual analysis review

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Science of the Total Environment 2024年 929卷 172576页

作者： Jing, Liandong Shi, Tianyu Chang, Yulung Meng, Xingliang He, Shuai Xu, Hang Yang, Shengtao Liu, Jia Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission Institute of Qinghai-Tibet Plateau School of Chemistry and Environment Southwest Minzu University Chengdu610041 China Department of Chemistry National Sun Yat-sen University Kaohsiung80424 Taiwan Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore117543 Singapore School of Material Science & Chemical Engineering Harbin University of Science and Technology Harbin China

As sustainable materials, cellulose-based materials have attracted significant attention in the field of environmental protection, resulting in the publication of numerous academic papers. However, there is a scarcity of literature that involving scientometric analysis within this specific domain. This review aims to address this gap and highlight recent research in this field by utilizing scientometric analysis and a historical review. As a result, 21 highly cited articles and 10 mostly productive journals were selected out. The scientometric analysis reveals that recent studies were objectively clustered into five interconnected main themes: extraction of cellulose from raw materials and its degradation, adsorption of pollutants using cellulose-based materials, cellulose-acetate-based membrane materials, nanocellulose-based materials, and other cellulose-based materials such as carboxymethyl cellulose and bacterial cellulose for environmental protection. Analyzing the distribution of author keywords and thoroughly examining relevant literature, the research focuses within these five themes were summarized. In the future, the development of eco-friendly and cost-effective methods for extracting and preparing cellulose and its derivatives, particularly nanocellulose-based materials, remains an enduring pursuit. Additionally, machine learning techniques holds promise for the advancement and application of cellulose-based materials. Furthermore, there is potential to expand the research and application scope of cellulose-based materials for environmental protection. © 2024

关键词： Environmental protection

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