检索结果-内蒙古大学图书馆

Point Cloud Classification Using Content-Based Transformer via Clustering in Feature Space

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 231-239页

作者： Yahui Liu Bin Tian Yisheng Lv Lingxi Li Fei-Yue Wang the State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190 the School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100190 IEEE the Transportation and Autonomous Systems Institute(TASI)and the Department of Electrical and Computer Engineering Purdue School of Engineering and TechnologyIndiana University-Purdue University Indianapolis(IUPUI)Indianapolis 46202 USA

Recently, there have been some attempts of Transformer in 3D point cloud classification. In order to reduce computations, most existing methods focus on local spatial attention,but ignore their content and fail to establish relationships between distant but relevant points. To overcome the limitation of local spatial attention, we propose a point content-based Transformer architecture, called PointConT for short. It exploits the locality of points in the feature space(content-based), which clusters the sampled points with similar features into the same class and computes the self-attention within each class, thus enabling an effective trade-off between capturing long-range dependencies and computational complexity. We further introduce an inception feature aggregator for point cloud classification, which uses parallel structures to aggregate high-frequency and low-frequency information in each branch separately. Extensive experiments show that our PointConT model achieves a remarkable performance on point cloud shape classification. Especially, our method exhibits 90.3% Top-1 accuracy on the hardest setting of ScanObjectN N. Source code of this paper is available at https://***/yahuiliu99/PointC onT.

关键词： Content-based Transformer deep learning feature aggregator local attention point cloud classification

来源：评论

学校读者我要写书评

暂无评论

A novel insight of degradation ibuprofen in aqueous by catalytic ozonation with supported catalyst:Supports effect on ozone mass transfer

引用

Journal of Environmental Sciences 2024年第11期145卷 216-231页

作者： Zizheng Huangfu Wei Ju Yunhan Jia Ruijun Ren Zhenbei Wang Chen Li Xiaomeng Shang Yujie Li Hongnan Liu YuWang Hao Zheng Fei Qi Amir Ikhlaq Jolanta Kumirska Ewa Maria Siedlecka Beijing Key Laboratory for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Beijing Forestry University Science Co. Ltd.Beijing 100083China Institute of Environment Engineering and Research University of Engineering and TechnologyLahore 54890Pakistan Department of Environmental Analysis Faculty of ChemistryUniversity of GdanskWita Stwosza 6380-308Poland

Catalytic ozonation is an effective wastewater purification ***,the low ozone mass transfer in packed bubble columns leads to low ozone utilization efficiency(OUE),poor organic degradation performance,and high energy ***,there is an urgent need to develop efficient supported catalysts that can enhancemass transfer and ***,the reaction mechanism of the support on ozone mass transfer remains unclear,which hinders the development of catalytic ozonation *** this study,lava rocks(LR)-supported catalysts,specifically CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR,were proposed for catalytic ozonation of IBP degradation due to their superior catalytic activity,stability,and high *** of CuMn_(2)O_(4)@LR or MnO_(2)–Co_(3)O_(4)@LR increased IBP removal efficiency from 85%to 91%or 88%,and reduced energy consumption from 2.86 to 2.14 kWh/m^(3)or 2.60 kWh/m^(3),*** improvement was attributed to LRsupported catalysts enhancing mass transfer and promoting O3 decomposition to generate•OH and•O_(2)^(−),leading to IBP ***,this study investigated the effects of ozone dose,supporter sizes,and catalyst components on ozone-liquid mass *** results revealed that the size of the supporter influenced stacked porosity and consequently affected ozone mass ***-sized LR(kLa=0.172 min^(−1))exhibited better mass transfer compared to smaller-sized *** on these findings,it was concluded that both CuMn_(2)O_(4)@LR and MnO_(2)–Co_(3)O_(4)@LR are potential catalysts for catalytic ozonation in residual IBP degradation of pharmaceutical wastewater,and LR showed good credibility as a catalyst *** the effects of supporters and active components on ozone mass transfer provides a fundamental principle for designing supported catalysts in catalytic ozonation applications.

关键词： Catalytic ozonation Lava rocks Overall volumetric mass transfer coefficient Supported catalyst

来源：评论

学校读者我要写书评

暂无评论

Tunable vortex radiation source driven by free electrons

引用

Optics Letters 2025年第10期50卷 3333-3336页

作者： Li, Sirui Li, Tianyi Sun, Jingbo Wen, Yongzheng Zhou, Ji State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Beijing100084 China State Key Laboratory of Nuclear Physics and Technology Institute of Heavy Ion Physics School of Physics Peking University Beijing100871 China

In this Letter, we propose a scheme to generate tunable vortex radiation through the interaction of free electrons with a dual-layer metasurface. The metasurface combines a field-enhancement layer with a phase-modulation layer to produce enhanced Smith–Purcell radiation (SPR) while enabling gradient phase control. This configuration efficiently converts the free-electron evanescent field into a coherent vortex beam. Simulation results indicate that the proposed structure generates coherent radiation with approximately 4.5 times the intensity of conventional vortex radiation under identical electron-beam conditions. The frequency and direction of the vortex radiation can be tuned by varying the electron velocity. Moreover, the structure enables coherent vortex radiation generation with a small number of electrons, including low-velocity electrons, without requiring strong focusing magnetic fields or periodic electron bunching. This work establishes an innovative approach for developing compact, efficient, and tunable vortex radiation sources based on free electrons. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Particle beam bunching

来源：评论

学校读者我要写书评

暂无评论

Digital CEOs in Digital Enterprises:Automating,Augmenting,and Parallel in Metaverse/CPSS/TAOs

引用

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 820-823页

作者： Juanjuan Li Rui Qin Sangtian Guan Xiao Xue Peng Zhu Fei-Yue Wang with State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China the College of Intelligence and Computing Tianjin UniversityTianjin 300072China School of Economics and Management Nanjing University of Science and TechnologyNanjing 210094China the State Key Laboratory for Management and Control of Complex Systems Chinese Academy of SciencesBeijing 100190 Faculty of Innovation Engineering Macao University of Science and TechnologyMacao 999078China

BIG models or foundation models are rapidly emerging as a key force in advancing intelligent societies[1]–[3]Their significance stems not only from their exceptional ability to process complex data and simulate advan... 详细信息

关键词： exceptional Auto advancing

来源：评论

学校读者我要写书评

暂无评论

Superior high-temperature wear resistance of an Ir-Ta-Ni-Nb bulk metallic glass

引用

Journal of Materials Science & technology 2023年第27期158卷 121-132页

作者： Fei Sun Shengtao Deng Jianan Fu Jiahua Zhu Dandan Liang Pengfei Wang Hang Zhao Feng Gong Jiang Ma Yanhui Liu Jun Shen Shenzhen Key Laboratory of High Performance Nontraditional Manufacturing College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Cross-scale Manufacturing Mechanics Southern University of Science and Technology Shenzhen 518055China Shanghai Engineering Research Center of Physical Vapor Deposition(PVD)Superhard Coating and Equipment Shanghai Institute of TechnologyShanghai 201418China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Wear resistance is a critical consideration in engineering *** this study,we demonstrated an Ir-Ta-Ni-Nb bulk metallic glass(BMG)with outstanding high-temperature wear resistance and revealed its promising applications in extreme *** wear behavior and mechanism were systemati-cally investigated from room temperature(RT)to 750℃.The results show that the wear rate increases from∼2.65×10^(-6)mm^(3)N^(-1)m^(-1)to∼10.56×10^(-6)mm^(3)N^(-1)m^(-1)in the temperature span RT to 400℃,following abrasive wear and flash temperature-induced oxidative wear during the ***,at the higher temperature of 600℃,further heating due to frictional heat leads to a softening of the wear surface,resulting in a maximum wear rate of∼20.99×10^(-6)mm^(3)N^(-1)m^(-1)under softness-driven abrasive wear as well as oxidative ***,the wear resistance at an even higher temperature of 750℃shows a paradoxical improvement of∼7.08×10^(-6)mm^(3)N^(-1)m^(-1),which is attributed to the formation of an oxide layer with a thickness of several microns,avoiding violent wear of *** re-sults demonstrate the unreported outstanding high-temperature wear resistance of the Ir-Ta-Ni-Nb BMG,especially its excellent capability to resist wear at 750℃,leading to the promising applications of BMG in the fields of aerospace,metallurgy,and nuclear industries.

关键词： High-temperature alloy Superior wear resistance Wear mechanisms Bulk metallic glass

来源：评论

学校读者我要写书评

暂无评论

Tracking control in Presence of Obstacles and Uncertainties for Bioinspired Spherical Underwater Robots

引用

Journal of Bionic engineering 2023年第1期20卷 323-337页

作者： Chunying Li Shuxiang Guo Jian Guo Graduate School of Engineering Kagawa UniversityTakamatsuKagawa761-0396Japan Key Laboratory of Convergence Medical Engineering System and Healthcare Technology the Ministry of Industry and Information TechnologySchool of Life Science and TechnologyBeijing Institute of TechnologyBeijing100081China Tianjin Key Laboratory for Control Theory and Applications in Complicated Systems and Intelligent Robot Laboratory Tianjin University of TechnologyBinshui Xidao Extension 391Tianjin300384China

During marine missions,AUVs are susceptible to external disturbances,such as obstacles,ocean currents,etc.,which can easily cause mission failure or *** this paper,considering the strong nonlinearities,external disturbances and obstacles,the kinematic and dynamic model of bioinspired Spherical Underwater Robot(SUR)was ***,the waypoints-based trajectory tracking with obstacles and uncertainties was proposed for SUR to guarantee its safety and ***,the Lyapunov theory was adopted to verify the stability and the Slide Mode control(SMC)method is used to verify the robustness of the control *** addition,a series of simulations were conducted to evaluate the effectiveness of proposed control *** tests,including path-following,static and moving obstacle avoidance were performed which verified the feasibility,robustness and effectiveness of the designed control ***,a series of experiments in real environment were performed to verify the performance of the control *** simulation and experimental results of the study supplied clues to the improvement of the path following capability and multi-obstacle avoidance of AUVs.

关键词： Path following Obstacle avoidance Bioinspired.Spherical underwater robot(SUR) Lyapunov theory

来源：评论

学校读者我要写书评

暂无评论

Effects of external parameters on plasma characteristics and uniformity in a dual cylindrical inductively coupled plasma

引用

Plasma Science and technology 2024年第12期26卷 63-74页

作者： Pengyu WANG Siyu XING Daoman HAN Yuru ZHANG Yong LI Cheng ZHOU Fei GAO Younian WANG Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China Lab of Advanced Space Propulsion and Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology Beijing Institute of Control EngineeringBeijing 100190People’s Republic of China

The dual cylindrical inductively coupled plasma source,compared to the conventional structure of inductively coupled plasma source,can significantly improve the uniformity of *** has an enhanced potential for application in processes,such as etching and ashing.A uniform plasma can be obtained by allowing the remote plasma from the upper chamber modulate the main plasma generated in the lower *** this study,a fluid model was employed to investigate a dual cylindrical inductively coupled Ar/O_(2)*** effects of external parameters on electron density,electron temperature,O atomic density,and plasma uniformity in the main chamber were studied,and the reasons were *** results of this study show that remote power can control the plasma uniformity and increase the plasma density in the main *** the remote power increased,plasma uniformity improved initially and then *** main power affected the plasma density at the edge of the main chamber and can modulate the plasma density in the main *** gas pressure affected both the uniformity and density of the *** the gas pressure increased,the plasma uniformity deteriorated,but the free radical density improved.

关键词： dual inductively coupled plasma remote plasma plasma uniformity fluid model

来源：评论

学校读者我要写书评

暂无评论

A PREA and OODA Computing Framework of Unmanned Systems to Perform Complex Tasks

IEEE Transactions on Intelligent Vehicles

引用

IEEE Transactions on Intelligent Vehicles 2024年 1-18页

作者： Yang, Dongsheng Yu, Lei Zhang, Yi Zhu, Fenghua Li, Qiang Cui, Huachao Ma, Qiongmin Fan, Lili Tian, Yonglin Jinan University Guangzhou China Intelligent Science & Technology Academy Limited of CASIC Beijing China State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of Automation Chinese Academy of Sciences Beijing China State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China 28th Research Institute of China Electronics Technology Group Corporation Nanjing China National Key Laboratory for Complex Systems Simulation National University of Defense Technology Changsha China School of Information and Electronics Beijing Institute of Technology Beijing China

A C2 computing framework for unmanned systems to perform complex tasks is proposed using methods of system of systems engineering, which is formed by combining the macro-scale command and control (C2) process mechanism model (PREA loop) and micro-scale C2 process mechanism model (OODA loop). Guided by PREA loop and OODA loop, the computing framework is divided into four steps and three kinds of transformations. The four steps are design, construction, operation monitoring, and assessment. The three transformations are tactical feedback, campaign feedback, and strategic feedback. A C2 organization model of joint landing combat force is established against the background of a typical complex task of joint landing operation, and the C2 computing framework based on the PREA &OODA is used to implement the C2 activities of the joint landing combat force. The influence of the computing framework on the performance of unmanned systems under different task conditions is verified, including task coordination load, task efficiency and sensitivity of unmanned systems response. Authors

关键词： Feedback

来源：评论

学校读者我要写书评

暂无评论

Numerical investigation on unsteady characteristics of ducted fans in ground effect

引用

Chinese Journal of Aeronautics 2023年第9期36卷 79-95页

作者： Yiwei LUO Tianfu AI Yuhang HE Bin XU Yuping QIAN Yangjun ZHANG State Key Laboratory of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China Vehicle Research Center School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ducted fans are widely used in various applications of Unmanned Aerial Vehicles(UAVs)due to the high efficiency,low noise and high *** unsteady characteristics of ducted fans flying near the ground are significant,which may bring stability *** this paper,the sliding mesh technology is applied and the Unsteady Reynolds Averaged Navier-Stokes(URANS)method is adopted to evaluate the influence of ground on the aerodynamic performance of ducted *** time-averaged results show that the ground leads to the decrease of duct thrust,the increase of rotor thrust and the decrease of total *** transient results show that there exist small-scale stall cells with circumferential movements in ground *** stall cells start to appear at the blade root when the height is 0.8 rotor radius distance,and arise at both the blade root and tip when the height drops to *** is found that the unsteady cells rotate between blade passages with an approximate relative speed of 30%-80%of the fan speed,and lead to thrust fluctuations up to 37%of the total *** results are essential to the flight control design of the ducted fan flying vehicle,to ensure its stability in ground effect.

关键词： Computational fluid dynamics Ducted fan Ground effect Thrust fluctuations UAV

来源：评论

学校读者我要写书评

暂无评论

Aerodynamic/control integrated optimization method for unpowered high-speed vehicle configuration design

引用

Chinese Journal of Aeronautics 2024年第7期37卷 153-167页

作者： Xin PAN Linlin WANG Li LI Lulu JIANG Gang CHEN State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China Shannxi Key Laboratory for Environment and Control of Flight Vehicle School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China Beijing Institute of Space Long March Vehicle Beijing 100076China AVIC Xi’an Aeronautics Computing Technique Research Institute Xi’an 710068China

The unpowered high-speed vehicle experiences a significant coupling between the disciplines of aerodynamics and control due to its characteristics of high flight speed and extensive maneuverability within large *** conventional aircraft conceptual design process follows a sequential design approach,and there is an artificial separation between the disciplines of aerodynamics and control,neglecting the coupling effects arising from their *** a result,this design process often requires extensive iterations over long periods when applied to high-speed vehicles,and may not be able to effectively achieve the desired design *** enhance the overall performance and design efficiency of high-speed vehicles,this study integrates the concept of Active control technology(ACT)from modern aircraft into the philosophy of aerodynamic/control integrated *** integrated optimization strategies,with differences in coupling granularity,have been ***,these strategies are put into action on a biconical vehicle that operates at Mach *** results reveal that the comprehensive performance of the synthesis optimal model derived from the aerodynamic/control integrated optimization strategy is improved by 31.76%and 28.29%respectively compared to the base model under high-speed conditions,demonstrating the feasibility and effectiveness of the method and optimization strategies ***,in comparison to the single-stage strategy,the multi-stage strategy takes into deeper consideration the impact of control *** a result,the control performance of the synthesis opti-mal model derived from the multi-stage strategy improves by 13.99%,whereas the single-stage strategy only achieves a 5.79%*** method enables a fruitful interaction between aerodynamic configuration design and control system design,leading to enhanced overall performance and design ***,it improves the controllability of high-sp

关键词： Aerodynamic/control Integrated Optimization MDO High-speed vehicle Shape Optimization controllability

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：