检索结果-内蒙古大学图书馆

SSRN 2024年

作者： Li, Penghao Zhang, Bangji Zhang, Zheshuo Hu, Wen Zhang, Jie Dai, Di State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha China Intelligent Transportation System Research Center Hangzhou City University Hangzhou China School of Vehicle and Mobility Tsinghua University Beijing China College of Automotive and Mechanical Engineering Changsha University of Science and Technology Changsha China

The automatic installation of panels has become crucial in numerous industries scenarios. This paper proposed a trajectory planning method to addresses the position and posture adjustment of panel installation using redundant articulating cranes. Configuration space of the crane and rotation matrix are combined to investigate the strong coupling of the panel's position and posture. Moreover, the study combines the motion modes of the crane with the sequential analysis of redundant motion to assess energy consumption, incorporating energy efficiency as one of the planning objectives. Simultaneously, an intrinsic connection between the motion sequences within the C-space and safety considerations is analyzed. The installation experiment is performed with a real crane. The experimental results indicate that the proposed method achieves the function of installation of panels, which can make both the panel’s position and posture safely reach the predetermined state with less energy consume. © 2024, The Authors. All rights reserved.

关键词： Cranes

来源：评论

学校读者我要写书评

暂无评论

Automated Creation of Topological Structure Models of Parallel Mechanisms for Kinematic Performance Evaluation

Automated Creation of Topological Structure Models of Parall...

引用

International Conference on Advanced Robotics and Mechatronics (ICARM)

作者： Hongye Wu Ping Lin Yue Ma Bin Li Qi Liu Hongqing Li Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin China

Considering the diversity of topological structures of parallel mechanisms (PMs), this paper presents an approach for the automated generation of topological structure models based on CAD technology. In this method, joints and links are treated as fundamental elements in the skeleton model of a mechanical system, leading to the development of a library of fundamental components readily available to compose a variety of limbs and PMs. A connection graph and its data structure are then developed for describing, in a hierarchical manner, the assembly information among the fundamental components. Equipped with the knowledge and information mentioned above, the limbs and PMs can finally be assembled automatically by identifying and imposing the geometrical constraints that have been already embedded in the models. The merit of this method lies in that 3D schematic diagrams (termed topological structure models) of various limbs and PMs can be created in an illustrative manner by properly selecting a set of fundamental components and then setting their connections, leading to the digitalized and visible topological structure models that are readily for kinematic performance evaluation. Combined with the CAD-CAE integration technology for the mechanical structure design and static/dynamic performance evaluation, a digital design and simulation framework can be formulated for the rapid design of parallel robotic equipment.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Visualizing the dynamic progression of backward erosion piping in a Hele-Shaw cell

引用

Journal of Zhejiang University-science A(Applied Physics & Engineering) 2022年第11期23卷 945-954页

作者： Gang ZHENG Jing-bo TONG Tian-qi ZHANG Zi-wu WANG Xun LI Ji-qing ZHANG Chun-yu QI Hai-zuo ZHOU Yu DIAO MOE Key Laboratory of Coast Civil Structure Safety Tianjin UniversityTianjin 300072China School of Science Tianjin UniversityTianjin 300072China China Railway Design Corporation Tianjin 300308China National Engineering Laboratory for Digital Construction and Evaluation Technology of Urban Rail Transit Tianjin 300308China

With the utilization of underground space,backward erosion piping(BEP)has been observed in many underground structures(e.g.,shield tunnels)founded on sandy ***,due to invisibility,the geometry of the eroded pipe and its spatial evolution with time during the piping process was still not *** this study,we developed a Hele-Shaw cell to visualize the dynamic progression of *** imaging process technology,we obtained a typical process of BEP(the erosion process can be divided into a piping progression phase and a piping stabilization phase),quantitatively characterized the formation of erosion pipes,and compared the patterns of erosion(e.g.,the erosion area A and the maximum erosion radius R)that spontaneously develop under different fluxes of *** most interesting finding is that the sand grains in a thicker Hele-Shaw model are easier to dislodge,which is possibly due to the granular system in a thicker model having more degrees of freedom,reducing the stability of the sand grains.

关键词： Backward erosion piping(BEP) Dynamic progression Hele-Shaw cell Visualize Imaging processing technology

来源：评论

学校读者我要写书评

暂无评论

Enhanced Adaptive Disturbance Observer for Sensorless Control of PMSM With Multi-harmonics Suppression Characteristics

引用

IEEE Journal of Emerging and Selected Topics in Power Electronics 2025年

作者： Qin, Qinghai Yi, Xinqiang Yu, Zhongjun Yu, Haitao Fang, Shuhua Southeast University School of Electrical Engineering Nanjing210096 China Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan430033 China East Lake Laboratory Wuhan430202 China

The inverter nonlinearity and spatial flux harmonics inevitably result in the back electromotive force (BEMF) harmonics in permanent magnet synchronous motor (PMSM), which deteriorates the performance of the model-based sensorless control. To settle the problem, this article proposes an enhanced adaptive disturbance observer by reconstructing the observer structure based on the pre-designed enhanced complex coefficient filter (ECCF). An ECCF with specific harmonic filtering capability based on conventional complex coefficient filter and multi-frequency suppression module is pre-constructed. Based on the reverse design method, the structure of the conventional disturbance observer is reconstructed into the desired ECCF structure. Multi-harmonics can be suppressed without cascading additional filtering networks after the conventional BEMF observers. The sensorless control algorithm studied is verified by the comparative experiments on a 1 kW PMSM platform. © 2013 IEEE.

关键词： Sensorless control

来源：评论

学校读者我要写书评

暂无评论

Anti-Fatigue Nanomechanics in the Pre-Cracked Graphene-Copper Artificial Nacre Under Cyclic Tension

SSRN

引用

SSRN 2023年

作者： Liu, Xiaoyi Xu, Yunfei Shi, Jinchun Zhu, YinBo Zhang, Sen Wu, HengAn Mechanics+X Laboratory Chengdu Development Center of Science and Technology China Academy of Engineering Physics Chengdu610200 China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Hefei230027 China

The fatigue performance of pre-cracked graphene-copper artificial nacre (GrCu nacre) under cyclic tensile loading is investigated using theoretical analysis and molecular dynamics (MD) simulations. Mechanical models are proposed to describe the fatigue performance of GrCu nacre, which agree well with MD simulations. Compared with nanocomposites consisting of large graphene sheets, graphene fragments cannot improve the ultimate strength of GrCu nacre, but significantly improve its fatigue limit. This anti-fatigue effect is dominated by the graphene-copper interfaces with van der Waals interactions, which can be adjusted by tailoring the architectural parameters of GrCu nacre. The ultimate strength of nacre decreases as the volume fraction of graphene increases. The fatigue limit of GrCu nacre decreases as the length of graphene fragments increases, and can be approximately described by a quadratic function of interlayer repeat spacing. An anomalous weakening effect occurs when the in-plane distance between graphene fragments is less than 2 nm, while this effect can be ignored when it is higher than 2 nm. The fatigue ratio of common metals is ~0.4, whereas that of GrCu nacre is generally higher than 0.9. These underlying mechanisms and theoretical models can improve the fundamental understanding of the fatigue performance of composites with incoherent interfaces, as well as the bottom-up design of graphene-metal nanocomposites. © 2023, The Authors. All rights reserved.

关键词： Molecular dynamics

来源：评论

学校读者我要写书评

暂无评论

Bandwidth-Efficient Two-Server ORAMs with O(1) Client Storage

arXiv

引用

arXiv 2025年

作者： Wang, Wei Zhang, Xianglong Xu, Peng Chen, Rongmao Yang, Laurence Tianruo School of Computer Science and Technology Huazhong University of Science and Technology Wuhan430074 China Hubei Key Laboratory of Distributed System Security School of Cyber Science and Engineering Huazhong University of Science and Technology Wuhan430074 China Jinyinhu Laboratory Wuhan430040 China School of Computer National University of Defense Technology Changsha410073 China School of Computer and Artificial Intelligence Zhengzhou University Zhengzhou450001 China Department of Computer Science St. Francis Xavier University AntigonishNSB2G 2W5 Canada

Oblivious RAM (ORAM) allows a client to securely retrieve elements from outsourced servers without leakage about the accessed elements or their virtual addresses. Two-server ORAM, designed for secure two-party RAM computation, stores data across two non-colluding servers. However, many two-server ORAM schemes suffer from excessive local storage or high bandwidth costs. To serve lightweight clients, it is crucial for ORAM to achieve concretely efficient bandwidth while maintaining O(1) local storage. Hence, this paper presents two new client-friendly two-server ORAM schemes that achieve practical logarithmic bandwidth under O(1) local storage, while incurring linear symmetric key computations. The core design features a hierarchical structure and a pairwise-area setting for the elements and their tags. Accordingly, we specify efficient read-only and write-only private information retrieval (PIR) algorithms in our schemes to ensure obliviousness in accessing two areas respectively, so as to avoid the necessity of costly shuffle techniques in previous works. We empirically evaluate our schemes against LO13 (TCC’13), AFN17 (PKC’17), and KM19 (PKC’19) in terms of both bandwidth and time cost. The results demonstrate that our schemes reduce bandwidth by approximately 2 ∼ 4× compared to LO13, and by 16 ∼ 64× compared to AFN17 and KM19. For a database of size 214 blocks, our schemes are over 64× faster than KM19, while achieving similar performance to LO13 and AFN17 in the WAN setting, with a latency of around 1 second. Copyright © 2025, The Authors. All rights reserved.

关键词： Virtual addresses

来源：评论

学校读者我要写书评

暂无评论

Anomaly Detection for Stochastic Networked Cyber-Physical systems: A Statistical Approach

Anomaly Detection for Stochastic Networked Cyber-Physical Sy...

引用

International Conference on Control and Automation (ICCA)

作者： Yamin Yan Minyue Fu Maria M. Seron School of Electrical and Electronic Engineering Nanyang Technological University Singapore Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and Technology School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China School of Engineering The University of Newcastle Callaghan NSW Australia

ISBN: (数字)9798350354409

ISBN: (纸本)9798350354416

In this paper, we investigate the anomaly detection problem within stochastic networked cyber-physical systems. We introduce an anomaly detection scheme centered on estimator design employing a statistical approach. Specifically, we extend the statistical method recently developed for single systems to networked control scenarios. Additionally, we analyse the detection of several representative anomalies through this statistical approach. We then apply our anomaly detection strategy to a power network system exposed to such anomalies. Our findings demonstrate that the proposed design effectively detects these anomalies, which simpler methods relying solely on residual assessment with a threshold fail to identify.

关键词： Analytical models Automation Statistical analysis Stochastic processes Cyber-physical systems Control systems Anomaly detection

来源：评论

学校读者我要写书评

暂无评论

Chern Number Tunable Quantum Anomalous Hall Effect in Compensated Antiferromagnets

arXiv

引用

arXiv 2024年

作者： Liang, Wenhao An, Jiaqi Li, Zeyu Ren, Yafei Qiao, Zhenhua Niu, Qian International Centre for Quantum Design of Functional Materials CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics Department of Physics University of Science and Technology of China Anhui Hefei230026 China Department of Physics and Astronomy University of Delaware NewarkDE19716 United States Hefei National Laboratory University of Science and Technology of China Hefei230088 China

We propose to realize the quantum anomalous Hall effect (QAHE) in two-dimensional compensated antiferromagnets without net spin magnetization. We consider antiferromagnetic MnBi2Te4 as a concrete example. By breaking the parity-time (PT) symmetry of even-layer MnBi2Te4, we find that the system can host the QAHE with a nonzero Chern number. We show that by controlling the antiferromagnetic spin configuration, for example, down/up/up/down that breaks PT symmetry, tetralayer MnBi2Te4 can host a Chern number C = −1. Such spin configuration can be stabilized by pinning the spin orientations of the surfaces. Furthermore, via tuning the on-site orbital energy and vertical electric fields, we find rich QAHE phases with tunable Chern number of |C| = 1, 2, 3. In addition, we reveal that the edge states are layer-selective and primarily locate at the boundaries of the bottom and top layers. Our work not only proposes a scheme to realize Chern number tunable QAHE in antiferromagnets without net spin magnetization, but also provides a platform for layer-selective dissipationless transport devices. Copyright © 2024, The Authors. All rights reserved.

关键词： Electric fields

来源：评论

学校读者我要写书评

暂无评论

Exploring GitHub Topics: Unveiling Their Content and Potential

Exploring GitHub Topics: Unveiling Their Content and Potenti...

引用

Software Services Engineering (SSE) IEEE International Conference on

作者： Jiaqi Zhang Yanchun Sun Yuqi Zhou Jiawei Wu Huizhen Jiang Gang Huang Key Laboratory of High Confidence Software Technologies Ministry of Education School of Computer Science Peking University Beijing P.R. China School of Software and Microelectronics Peking University Beijing P.R. China National Key Laboratory of Data Space Technology and System

ISBN: (数字)9798350368512

ISBN: (纸本)9798350368529

N owadays, software service design is increasingly oriented toward addressing human needs, aiming to extract users' needs and behavioral patterns from open-source data. GitHub's massive open-source repositories have emerged as a crucial data source for software service researchers seeking to extract valuable insights and develop software services tailored for developers. Both GitHub and researchers are making efforts to help researchers and developers better utilize GitHub data. In 2017, GitHub launched “topics”, enabling developers to assign keywords to repositories. This feature fosters linkages between repositories, aiding in their discovery by other developers. For software development, topics offer two significant values. First, topics provide researchers with new insights to better mine GitHub data and provide enhanced support for developers. Second, developers utilizing topics to annotate their repositories may enhance their visibility and engagement within the community, potentially bolstering their repository's popularity. Despite the increasing number of topics, no research has systematically analyzed their content and potential value. Therefore, we conduct the first empirical study on topics, providing valuable conclusions for future researchers and developers. We conduct a case study encompassing 900 repositories to analyze the information explicitly presented in the topic content, and three experiments to verify whether topics have the potential to be used as repository features and user features in GitHub-related studies. Furthermore, we delve into the correlation between topics and repository popularity, by analyzing the number of stars repositories received. Our findings cover the composition of topic content, the potential value of topics for GitHub-related research, and the impact of topics on repository popularity.

关键词： Couplings Correlation Soft sensors Stars Focusing Feature extraction Behavioral sciences

来源：评论

学校读者我要写书评

暂无评论

Modeling, simulation and experiment of an origami robot with a coupled bar-hinge mechanism

Modeling, simulation and experiment of an origami robot with...

引用

Fully Actuated system Theory and Applications (CFASTA), Conference on

作者： Junpeng Mai Hanzhao Shao Shaojie Liu Yuanzhuo Zhang Liangming Chen Huijuan Feng School of System Design and Intelligent Manufacturing and Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology Shenzhen P. R. China Department of Electronic and Electrical Engineering Southern University of Science and Technology Shenzhen P. R. China Department of Mechnical and Energy Engineering Southern University of Science and Technology Shenzhen P. R. China

ISBN: (数字)9798350373691

ISBN: (纸本)9798350373707

This paper aims to analyze the motion behavior of an origami robot with a coupled bar-hinge mechanism. By disassembling the planar six-hinge mechanism into two planar four-hinge mechanisms with coupled motion, this paper derives the kinematics of the planar six-hinge mechanism based on the algebraic differential kinematics of the planar four-hinge motions. The rotational angle change and the moving step length of the origami robot are further calculated. Finally, the theoretical motion model is verified with the motion simulation data of the planar six-hinge mechanism origami robot in SolidWorks and the experimental data of the physical model. This verification proves the feasibility of the theoretical analysis, simulation model, and physical model.

关键词： Solid modeling Analytical models Prototypes Kinematics Three-dimensional printing Mathematical models Data models

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：