检索结果-内蒙古大学图书馆

arXiv 2022年

作者： Wang, Guangming Feng, Zhiheng Jiang, Chaokang Wang, Hesheng Department of Automation Key Laboratory of System Control and Information Processing of Ministry of Education Key Laboratory of Marine Intelligent Equipment and System of Ministry of Education Shanghai Engineering Research Center of Intelligent Control and Management Shanghai Jiao Tong University Shanghai200240 China Engineering Research Center of Intelligent Control for Underground Space Ministry of Education School of Information and Control Engineering Advanced Robotics Research Center China University of Mining and Technology Xuzhou221116 China

Scene flow represents the 3D motion of each point in the scene, which explicitly describes the distance and the direction of each point’s movement. Scene flow estimation is used in various applications such as autonomous driving fields, activity recognition, and virtual reality fields. As it is challenging to annotate scene flow with ground truth for real-world data, this leaves no real-world dataset available to provide a large amount of data with ground truth for scene flow estimation. Therefore, many works use synthesized data to pre-train their network and real-world LiDAR data to finetune. Unlike the previous unsupervised learning of scene flow in point clouds, we propose to use odometry information to assist the unsupervised learning of scene flow and use real-world LiDAR data to train our network. Supervised odometry provides more accurate shared cost volume for scene flow. In addition, the proposed network has mask-weighted warp layers to get a more accurate predicted point cloud. The warp operation means applying an estimated pose transformation or scene flow to a source point cloud to obtain a predicted point cloud and is the key to refining scene flow from coarse to fine. When performing warp operations, the points in different states use different weights for the pose transformation and scene flow transformation. We classify the states of points as static, dynamic, and occluded, where the static masks are used to divide static and dynamic points, and the occlusion masks are used to divide occluded points. The mask-weighted warp layer indicates that static masks and occlusion masks are used as weights when performing warp operations. Our designs are proved to be effective in ablation experiments. The experiment results show the promising prospect of an odometry-assisted unsupervised learning method for 3D scene flow in real-world data. Copyright © 2022, The Authors. All rights reserved.

关键词： Deep learning

来源：评论

学校读者我要写书评

暂无评论

Parametric Study on SUV-e-bike Collision for Safety Test & Evaluation Regulations

Parametric Study on SUV-e-bike Collision for Safety Test & E...

引用

2021中国汽车工程学会年会暨展览会

作者： Liu Yu Wan Xinming Xu Wei Shi Liangliang Bai Zhonghao State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University State Key Laboratory of Vehicle NVH and Safety Technology China Automotive Engineering Research Institute Co. Ltd.

To explore the kinematics and injury response of the rider's head after the collision with the vehicle,and to determine the test and evaluation boundary for its *** accident involving an e-bike was reconstructed based on an automatic operation framework,then the reliability of the reconstruction model was verified from comparisons of rider's kinematics,the rest position of three participants,and injury with accident ***,a total of 1296 parametric cases were performed by the automatic operation framework,which was based on the validated model with a full factorial experimental design according to the collision boundary such as velocity,position,and angle from ***,a data set with 1005 valid cases were used to discuss the distribution patterns of the head's kinematics and injury response when colliding with the vehicle such as initial impacting time,linear and angular velocity,WAD,and also for head injury criteria(HIC).The results show that WAD is positively correlated with the size of the rider and vehicle *** head contact points on the vehicle are located before WAD2100,and WAD1100-1600 should be considered significant for riders' protection.92 % of the head impacting linear velocity are lower than 50 km/h,78 % is less than 40 km/*** collision angle of50-70° accounts for 62%,and the average angle of 5,50,95 are 57°,61°,62° *** subsystem impactor,within test area of WAD1000 ～2100 and with impacting velocity of 40 km/h and angle of 650 in current pedestrian protection regulation,seems to be applicable to the boundary of test and evaluation for SUV to e-bike riders.82% of cases with head initial collision time are less than 140 ms,and head injuries of e-bike riders mainly come from ground *** a preliminary exploration,distribution patterns of rider's kinematics and injury response in this article will provide data and theoretical support for formulation and revision of evaluation regulations an

关键词： e-bike rider parametrization kinematics and injury response test & evaluation regulations

来源：评论

学校读者我要写书评

暂无评论

Self-Supervised Plant Phenotyping by Combining Domain Adaptation with 3D Plant Model Simulations: Application to Wheat Leaf Counting at Seedling Stage

引用

Plant Phenomics 2023年第2期5卷 226-238页

作者： Yinglun Li Xiaohai Zhan Shouyang Liu Hao Lu Ruibo Jiang Wei Guo Scott Chapman Yufeng Ge Benoit de Solan Yanfeng Ding Frédéric Baret Plant Phenomics Research Centre Academy for Advanced Interdisciplinary StudiesJiangsu Collaborative Innovation Center for Modern Crop ProductionNanjing Agricultural UniversityNanjingChina Key Laboratory of Image Processing and Intelligent Control School of Artificial Intelligence and AutomationHuazhong University of Science and TechnologyWuhanChina Graduate School of Agricultural and Life Sciences The University of Tokyo1-1-1 Midori-choNishitokyo CityTokyoJapan School of Agriculture and Food Sciences The University of QueenslandSt.LuciaQueensland 4072Australia Department of Biological Systems Engineering University of Nebraska-LincolnLincolnNebraska 68583United States INRAE Avignon UniversitéUMR EMMAHUMT CAPTE228route de l’aérodrome-CS 4050984914 Avignon Cedex 9France ARVALIS Institut du Végétal 3 Rue Joseph et Marie Hackin75116 ParisFrance

The number of leaves at a given time is important to characterize plant growth and *** this work,we developed a high-throughput method to count the number of leaves by detecting leaf tips in RGB *** digital plant phenotyping platform was used to simulate a large and diverse dataset of RGB images and corresponding leaf tip labels of wheat plants at seedling stages(150,000 images with over 2 million labels).The realism of the images was then improved using domain adaptation methods before training deep learning *** results demonstrate the efficiency of the proposed method evaluated on a diverse test dataset,collecting measurements from 5 countries obtained under different environments,growth stages,and lighting conditions with different cameras(450 images with over 2,162 labels).Among the 6 combinations of deep learning models and domain adaptation techniques,the Faster-RCNN model with cycle-consistent generative adversarial network adaptation technique provided the best performance(R^(2)=0.94,root mean square error=8.7).Complementary studies show that it is essential to simulate images with sufficient realism(background,leaf texture,and lighting conditions)before applying domain adaptation ***,the spatial resolution should be better than 0.6 mm per pixel to identify leaf *** method is claimed to be self-supervised since no manual labeling is required for model *** self-supervised phenotyping approach developed here offers great potential for addressing a wide range of plant phenotyping *** trained networks are available at https://***/YinglunLi/Wheat-leaf-tip-detection.

关键词： Wheat seedling Plant

来源：评论

学校读者我要写书评

暂无评论

Effect of PEO ceramic coating on AZ91D magnesium alloy under laser-assisted irradiation on the in-situ growth and corrosion resistance of MgAl-LDH film

引用

Journal of Alloys and Compounds 2025年 1029卷

作者： Wu, Guolong Li, Lin Zhu, Lebin Yin, Yanyi Wang, Ye Wen, Chen Su, Lei Lei, Liming Yao, Jianhua College of Mechanical Engineering Zhejiang University of Technology Hangzhou310014 China Ministry of Education/Zhejiang Provincial Key Laboratory of Special Equipment Manufacturing and Advanced Processing Technology China Institute of Laser Advanced Manufacturing Zhejiang University of Technology Hangzhou310014 China Beijing Spacecrafts Manufacturing Factory Co. Ltd. Beijing100094 China Taihan Laboratory Chengdu610213 China

Mg-Al layer double hydroxide (MgAl-LDH) film was prepared in-situ on laser-assisted plasma electrolytic oxidation (Laser/PEO) ceramic coating of AZ91D magnesium alloy containing endogenous cation sources (Mg and Al) to further enhance the corrosion protection. Laser-assisted irradiation significantly improved the specific surface area as well as the endogenous Al elemental content and distribution of the PEO ceramic coating, which greatly facilitated the in-situ rapid and dense growth of the LDH film on the PEO ceramic coating. The Laser/PEO-LDH composite coating exhibited best corrosion protection ability, which was attributed to the synergistic effect between the higher percentage of spinel MgAl2O4 and the denser LDH film. © 2025 Elsevier B.V.

关键词： Corrosion resistant coatings

来源：评论

学校读者我要写书评

暂无评论

Generating Bell states and Werner states of two qubits via optical field

arXiv

引用

arXiv 2024年

作者： Jiang, Dengkui Zhai, Cuilu Song, Yaju Peng, Zhaohui Yuan, Jibing Tang, Shiqing Lu, Wangjun Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal University Changsha410081 China Department of Maths and Physics Hunan Institute of Engineering Xiangtan411104 China College of Physics and Electronic Engineering Hengyang Normal University Hengyang421002 China Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials Department of Physics Hunan University of Science and Technology Xiangtan411201 China

In this paper, we investigate how the evolution of the states of two qubits initially in a direct product state can be controlled by the optical field in a Tavis-Cummings (TC) model. For the two qubits initially in the direct product state, we find that their matrix elements at any moment can be modulated by the coefficients of the optical field initial states in the number state space. We propose a method for preparing an X-type state of two qubits. Subsequently, for descriptive convenience, we divide the Bell states of the two qubits into two kinds in the paper. When both qubits are initially in the ground state, we find that the two qubits can be controlled to produce the first type of Bell state by the superposition state optical field that is initially in the next-nearest-neighbor number state and that the production of any of the first type of Bell states can be controlled by controlling the phase between the two next-nearest-neighbor number states. When one of the two qubits is in the ground state, and the other is in the excited state, we can control the two qubits to produce the second type of Bell state by the single-photon number state optical field. Finally, we study the generation of Werner states by controlling two qubits initially, both in the ground state, using an optical field. © 2024, CC BY.

关键词： Ground state

来源：评论

学校读者我要写书评

暂无评论

Research on the Bonding Properties of Vitrified Bonds with Porous Diamonds and the Grinding Performance of Porous Diamond Abrasive Tools

Research Square

引用

Research Square 2021年

作者： Li, Jianwei Fang, Wenjun Wan, Long Liu, Xiaopan Hu, Weida Cao, Dan Han, Kai Li, Yingying Yan, Yonggao Hunan University College of Materials Science and Engineering China Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body China Hunan University of Technology Liling ceramic institute China Shangqiu Institute of Technology China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology China

Ordinary diamond presents the disadvantages of poor self-sharpening and concentrated grinding stress when it is used as an abrasive. Moreover, this kind of diamond cannot be well wetted by the vitrified bond, resulting in a lower holding force of the binder to the abrasives (i.e., the diamond is easy to detach from the binder matrix during grinding). These comprehensive factors not only reduce the surface quality of the processed workpiece, but also hinder the processing efficiency. In order to solve these problems, a new type of porous diamond with high self-sharpening properties was prepared using a thermochemical corrosion method in this study. Our results showed a great improvement in pore volume and specifisurface area of the porous diamond compared with ordinary diamond abrasive particles, and the holding force and wettability of vitrified bond to the porous diamond abrasive particles were also improved. Compared with ordinary diamond abrasive tools, porous diamond abrasive tools showed a 29.6% increase in grinding efficiency, a 15.5% decreased in grinding ratio, a 27.5% reduction in workpiece surface roughness, and the scratches on the silicon wafer surface were reduced and refined. © 2021, CC BY.

关键词： Grinding (machining)

来源：评论

学校读者我要写书评

暂无评论

Design and Implementation of Subsynchronous Damping controller for HVDC 4

Design and Implementation of Subsynchronous Damping Controll...

引用

2019 4th International Seminar on Computer technology, Mechanical and Electrical Engineering, ISCME 2019

作者： Wenpei, Zhu Aimin, An Yifan, Xu Yingyin, Zhao College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou730050 China Key Laboratory of Gansu Advanced Control for Industrial Processes Lanzhou730050 China

The interaction between High Voltage Direct Current (HVDC) transmission lines and turbogenerator units will cause the damage of the generator shafting and the electrical system by exchanging energy at one or more lower synchronous frequencies, resulting in the damage or even breakage of the generator shafting, seriously affecting the safe operation of the power system. To solve this problem, the Supplementary Subsynchronous Damping controller (SSDC) is an effective method to suppress the secondary synchronous oscillation of turbogenerator units connected to rectifier side caused by HVDC. This paper combines the first standard model parameters of IEEE subsynchronous oscillation with CIGRE HVDC transmission system, and builds a HVDC transmission test system for Subsynchronous Oscillations(SSO) research in PSCAD. Based on signal test method, a narrow band SSDC is designed, and the damping in each synchronization frequency band is greatly increased. When the proportional coefficient is appropriate, the electrical damping is positive. The effectiveness of the designed SSDC is also verified by time domain simulation. © 2020 IOP Publishing Ltd. All rights reserved.

关键词： Damping

来源：评论

学校读者我要写书评

暂无评论

Observation of Copropagating Chiral Zero Modes in Magnetic Photonic Crystals

引用

Physical Review Letters 2025年第3期134卷 033802-033802页

作者： Zhongfu Li Shaojie Ma Shuwei Li Oubo You Yachao Liu Qingdong Yang Yuanjiang Xiang Peiheng Zhou Shuang Zhang New Cornerstone Science Laboratory Department of Physics The University of Hong Kong Hong Kong 999077 China Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing Department of Optical Science and Engineering School of Information Science and Technology Fudan University Shanghai 200433 China National Engineering Research Center of Electromagnetic Radiation Control Materials Key Laboratory of Multi-spectral Absorbing Materials and Structures of Ministry of Education University of Electronic Science and Technology of China Chengdu China College of Electronics and Information Engineering Shenzhen University 518060 Shenzhen China School of Physics and Electronics Hunan University Changsha 410082 China Materials Innovation Institute for Life Sciences and Energy (MILES) HKU-SIRI 518000 Shenzhen China

Topological singularities, such as Weyl points (WPs) and Dirac points, can give rise to unidirectional propagation channels known as chiral zero modes (CZMs) when subject to a magnetic field. CZMs, as distinct zeroth Landau levels (bulk modes) with high degeneracy, are responsible for intriguing phenomena like the chiral anomaly in quantum systems. The propagation direction of each CZM is determined by both the applied magnetic field and the topological charge of the singularity point. While counterpropagating CZMs have been observed in 2D and 3D systems, the realization of copropagating CZMs has remained elusive. Here, we present the first experimental observation of copropagating CZMs in magnetic photonic crystals hosting a single pair of ideal Weyl points. By manipulating the crystal’s structural configuration and applying a uniform bias magnetic field, we spatially alter the locations of the WPs, creating pseudo-magnetic fields of opposite directions for different WPs. This arrangement results in a pair of CZMs that possess the same group velocity and copropagate. Our work opens up new possibilities for the topological manipulation of wave propagation and may lead to advancements in optical waveguides, switches, and various other applications.

关键词： Wave propagation

来源：评论

学校读者我要写书评

暂无评论

High-temperature oxidation and thermal shock resistance of laser-assisted PEO ceramic coatings on Ti6Al4V alloy

引用

Ceramics International 2025年

作者： Wu, Guolong Yin, Yanyi Wang, Rui Li, Lin Wang, Ye Wen, Chen Su, Lei Lei, Liming Yao, Jianhua College of Mechanical Engineering Zhejiang University of Technology Hangzhou310014 China Ministry of Education/Zhejiang Provincial Key Laboratory of Special Equipment Manufacturing and Advanced Processing Technology China Institute of Laser Advanced Manufacturing Zhejiang University of Technology Hangzhou310014 China Beijing Spacecrafts Manufacturing Factory Co. Ltd. Beijing100094 China Taihang Laboratory Chengdu610200 China

The oxidation and thermal shock resistance of the Ti6Al4V alloy is suboptimal when the service temperature exceeds 500 °C. In this study, plasma electrolytic oxidation (PEO) coatings and laser-assisted PEO (LPEO) coatings were prepared in NaAlO2-based electrolyte and employed to enhance the high-temperature performance of the Ti6Al4V alloy. SEM, EDS, XPS, and XRD systematically analyzed the microstructure and chemical composition of the coatings. Meanwhile, isothermal oxidation and thermal shock tests investigated the high-temperature resistance of each coated Ti6Al4V sample at 600 °C. The results showed that both PEO and LPEO coatings were characterized by a porous structure and contained Al2TiO5, rutile TiO2 and a small amount of anatase TiO2. The porosity of the LPEO coating gradually decreases with increasing laser irradiation energy, while the coating thickness and Al2TiO5 phase content gradually increase. After 100 h of oxidation at 600 °C, the mass gains of the bare and PEO coated samples were 1.581 mg cm−2 and 0.628 mg cm−2, with reaction rate constants (K) of 1.56 × 10−2 and 5.10 × 10−3, respectively. In contrast, the mass gain of the LPEO-60 coated sample prepared by 60 W laser irradiation was significantly lower, which was only 0.211 mg cm−2, and the K value was reduced to 5.77 × 10−4. Moreover, thermal shock tests showed that the reduction of microstructural defects and the increase of the low coefficient of thermal expansion Al2TiO5 phase content of the LPEO coatings are the main reasons for the excellent thermal shock resistance of the coatings. This strategy and research results are expected to be significant in optimizing PEO coatings and developing protective coatings for titanium alloys with enhanced high-temperature resistance. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Ceramic coatings

来源：评论

学校读者我要写书评

暂无评论

Thermal-Economic Optimization and Working Fluid Selection of Subcritical Organic Rankine System for Low-Temperature Waste Heat Recovery

SSRN

引用

SSRN 2022年

作者： Zhang, Chao Li, Yongwang Fu, Wencheng Zhiting, Tong Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

In the present study, multi-objective optimization is conducted to search for the best operating condition for a subcritical organic Rankine system with the trade-off between system exergy efficiency and dynamic payback period (PBP). A 150°C wastewater heat source is employed as a typical low-temperature heat source. Five decision variables are considered: turbine inlet temperature and pressure, pinch point temperature differences in evaporator and condenser, and condensing temperature. The multi-objective genetic algorithm combined with the backpropagation neural network method is employed as the optimization approach. In addition, the improved Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is developed to gain the optimal Pareto front solution for either working fluid and find the optimal working fluid among the candidates investigated. The results show that working fluid R236fa is the optimal solution, despite the minimum PBP for working fluid R123 and the maximum system exergy efficiency for working fluid R1234ze. Under the optimal working condition for working fluid R236fa, the system exergy efficiency and the PBP are 0.465 and 7.377 years, respectively. © 2022, The Authors. All rights reserved.

关键词： Multiobjective optimization

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：