检索结果-内蒙古大学图书馆

Phase-matching-free second-harmonic generation in an ultrahigh-order standing-wave field

Physical Review Applied 2024年第5期22卷 L051001-L051001页

作者： Qiheng Wei Hongrui Shan Hailang Dai Xianfeng Chen Institute of Fluid Physics China Academy of Engineering Physics Mianyang Sichuan 621900 China Research Center of Precision Sensing and Control Institute of Automation Chinese Academy of Sciences Beijing 100190 China Luoyang Institute for Robot and Intelligent Equipment Luoyang 471000 China Collaborative Innovation Center of Light Manipulations and Applications School of Physics and Electronics Shandong Normal University Jinan 250358 China

In nonlinear wavelength conversion processes, maintaining phase matching is crucial to ensuring the conservation of photon momentum. Consequently, the requirement for phase matching limits the effectiveness of all parametric nonlinear optical processes. Techniques such as quasi-phase-matching, birefringent phase matching, and higher-order-mode phase matching have been developed to address this limitation. However, these methods necessitate specific beam arrangements and precise dispersion engineering, and are typically narrowband. In this study, we demonstrate that a submillimeter metal-clad waveguide can bypass the phase-matching requirement for on-chip nonlinear wavelength conversion by exciting an ultrahigh-order standing-wave field at nonspecial matching incident angles. Additionally, efficient second-harmonic generation is observed within the submillimeter waveguide across a broad range of pump wavelengths (from visible to infrared). The results indicate that the ultrahigh-order standing-wave field mitigates traditional phase-matching constraints, facilitating nonlinear interactions and the miniaturization of nonlinear devices.

关键词： Frequency conversion Integrated optics Nonlinear waves Waveguides Optical second-harmonic generation

来源：评论

学校读者我要写书评

暂无评论

A policy gradient algorithm integrating long and short-term rewards for soft continuum arm control

引用

Science China(Technological Sciences) 2022年第10期65卷 2409-2419页

作者： DONG Xiang ZHANG Jing CHENG Long XU WenJun SU Hang MEI Tao School of Electrical Engineering and Automation Anhui UniversityHefei 230601China State Key Laboratory for Control and Management of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China Robotics Research Center Peng Cheng LaboratoryShenzhen 518055China

The soft continuum arm has extensive application in industrial production and human life due to its superior safety and flexibility. Reinforcement learning is a powerful technique for solving soft arm continuous control problems, which can learn an effective control policy with an unknown system model. However, it is often affected by the high sample complexity and requires huge amounts of data to train, which limits its effectiveness in soft arm control. An improved policy gradient method, policy gradient integrating long and short-term rewards denoted as PGLS, is proposed in this paper to overcome this issue. The shortterm rewards provide more dynamic-aware exploration directions for policy learning and improve the exploration efficiency of the algorithm. PGLS can be integrated into current policy gradient algorithms, such as deep deterministic policy gradient(DDPG). The overall control framework is realized and demonstrated in a dynamics simulation environment. Simulation results show that this approach can effectively control the soft arm to reach and track the targets. Compared with DDPG and other model-free reinforcement learning algorithms, the proposed PGLS algorithm has a great improvement in convergence speed and performance. In addition, a fluid-driven soft manipulator is designed and fabricated in this paper, which can verify the proposed PGLS algorithm in real experiments in the future.

关键词： soft arm control Cosserat rod deep reinforcement learning policy gradient algorithm high sample complexity

来源：评论

学校读者我要写书评

暂无评论

Boosting Explore-Exploit Behavior for Navigating Vehicle by Maintaining Informative Topological Frontier

IEEE Transactions on Intelligent Vehicles

引用

IEEE Transactions on Intelligent Vehicles 2024年 1-11页

作者： Liu, Qiming Cui, Xinru Liu, Zhe Wang, Hesheng Department of Automation Shanghai Jiao Tong University Shanghai China MoE Key Lab of Artificial Intelligence AI Institute Shanghai Jiao Tong University Shanghai China 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 Shanghai China

Target search in unknown environments places high demands not only on an autonomous vehicle's ability to perceive and interpret target cues, but also on its conscious of collecting these cues by active exploration. While existing navigation methods have successfully built target-driven policies by maintaining memory of explored areas, there has been a lack of focus on facilitating target-aware exploration-the informative frontier information at unexplored yet visible areas is often overlooked. In this paper, we introduce a novel topology-based memory structure, Frontier-enhanced Topological Memory (FTM), and a Hierarchical Topology Encoding and Extraction (HTEE) module, fostering the autonomous vehicle's awareness of both environmental exploration and target approach. Specifically, FTM innovatively incorporates informative ghost nodes on traditional topological map to represent unexplored yet visible regions. We leverage an online-trained implicit scene representation to estimate the positions and generate features of these ghost nodes. The HTEE then employs implicit graph convolutions and attention mechanisms to extract cognitive information from FTM, taking into account the hierarchical memory structure, target cues, and current state. Our design bolsters cognitive navigation decisions. The experiments in the high-fidelity environments, including performance tests, visualizations, and interpretability experiments, validate the effectiveness of our approach in enhancing the vehicle's exploratory behavior. The improved exploration awareness for target cue collection, in turn, enhances the success rate and path efficiency of target search. Furthermore, we demonstrate the adaptability of our algorithm in real-world physical environments. IEEE

关键词： Data mining

来源：评论

学校读者我要写书评

暂无评论

Instance Segmentation of Ice-Covered Transmission Line in Unmanned Aerial Vehicle Images 5

Instance Segmentation of Ice-Covered Transmission Line in Un...

引用

5th International Seminar on Artificial Intelligence, Networking and Information Technology, AINIT 2024

作者： Pan, Nianyi Sun, Jiacheng Zhou, Xinghong Li, Xiaomao School of Computer Engineering and Science Shanghai University Shanghai China School of Future Technology Shanghai University Shanghai China Research Institute of Usv Engineering School of Mechatronic Engineering and Automation Shanghai University Shanghai China

ISBN: (纸本)9798350385557

Unmanned aerial vehicle (UAV) detection of ice-covered transmission lines (ITL) is a crucial task for winter power grid maintenance. Instance segmentation offers robustness in handling complex scene variations in UAV images while providing instance-level information. However, the quality of instance segmentation heavily relies on precise pixel-level annotations, while predictions from low-cost annotations tend to be coarse. Therefore, this paper proposes a soft label mask optimization (SLMO) method to achieve high-quality segmentation results of ITL with only coarse annotations. Furthermore, to alleviate loss of feature details during multi-scale feature fusion, a pixel shuffle module (PSM) is introduced to replace the conventional interpolation sampling method. Combining these methods, this paper proposes a SLMO Network (SLMONet) based on the efficient SparseInst framework. Extensive experiments on our ITL datasets validate the effectiveness of SLMONet in segmenting ITL. © 2024 IEEE.

关键词： Electric lines

来源：评论

学校读者我要写书评

暂无评论

Adaptive Extended State Observer-Based Tracking control for PMSM Drive Systems With Uncertainties and Disturbances

Adaptive Extended State Observer-Based Tracking Control for ...

引用

2023 IEEE International Conference on Real-Time Computing and Robotics, RCAR 2023

作者： Zhang, Zhongjin Liu, Zhitai Li, Peng Cheng, Wei Lin, Weiyang Harbin Institute of Technology Research Institute of Intelligent Control and Systems Harbin150001 China Harbin Institute of Technology Shenzhen School of Mechanical Engineering and Automation Shenzhen518055 China Devol Advanced Automation Inc Shenzhen518101 China

ISBN: (纸本)9798350327182

With the aim of improving the robust tracking performance of permanent magnet synchronous motor (PMSM) drive systems, an indirect adaptive robust control strategy based on adaptive extended state observer (AESO) is developed in this paper. Firstly, the parameter estimation process is separated from the controller design, and the indirect adaptive law driven by the system input and output is adopted to guarantee the convergence and accuracy of parameter estimation. Secondly, an AESO is established to estimate the unmodeled characteristics and disturbances in the system, and the performance of disturbance estimation and compensation is improved by dynamically adjusting the observer gain. Finally, an adaptive tracking controller is synthesized using the backstepping method, and its stability is proven using Lyapunov analysis. Simulation results demonstrate the effective performance improvement of the synthesized controller for tracking control. © 2023 IEEE.

关键词： controllers

来源：评论

学校读者我要写书评

暂无评论

Discriminatively Constrained Semi-Supervised Multi-View Nonnegative Matrix Factorization with Graph Regularization

引用

Big Data Mining and Analytics 2024年第1期7卷 55-74页

作者： Guosheng Cui Ye Li Jianzhong Li Jianping Fan Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China Joint Engineering Research Center for Health Big Data Intelligent Analysis Technology Shenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China School of Computer Science and Control Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Nonnegative Matrix Factorization(NMF)is one of the most popular feature learning technologies in the field of machine learning and pattern *** has been widely used and studied in the multi-view clustering tasks because of its *** study proposes a general semi-supervised multi-view nonnegative matrix factorization *** algorithm incorporates discriminative and geometric information on data to learn a better-fused representation,and adopts a feature normalizing strategy to align the different *** specific implementations of this algorithm are developed to validate the effectiveness of the proposed framework:Graph regularization based Discriminatively Constrained Multi-View Nonnegative Matrix Factorization(GDCMVNMF)and Extended Multi-View Constrained Nonnegative Matrix Factorization(ExMVCNMF).The intrinsic connection between these two specific implementations is discussed,and the optimization based on multiply update rules is *** on six datasets show that the effectiveness of GDCMVNMF and ExMVCNMF outperforms several representative unsupervised and semi-supervised multi-view NMF approaches.

关键词： multi-view semi-supervised clustering discriminative information geometric information feature normalizing strategy

来源：评论

学校读者我要写书评

暂无评论

Digital Educational Resources in Industrial Radiography 7

Digital Educational Resources in Industrial Radiography

引用

7th International Conference on Information Technologies in engineering Education, Inforino 2024

作者： Kuvshinnikov, Vladimir Kovshov, Evgeny Korchagin, Valery JSC 'Research and Development Institute of Construction Technology - Atomstroy' Research Laboratory of Digital Computer Systems and Automation Moscow Russia Dmitry Mendeleev University of Chemical Technology of Russia Disruptive Engineering School of Chemical Engineering and Machinery Moscow Russia

ISBN: (纸本)9798350371369

Nowadays, the technological level of production is an important factor for all areas of modern economic development and life quality improvement. Neither in the informational, nor in the industrial sphere it is possible to produce in-demand, modern, and therefore high-tech and complex products without the establishment of an appropriate system of quality examination at multiple stages of production. This article deals with the problem of forming a comprehensive educational environment with the use of heterogeneous educational resources in the training of specialists in the radiation type of nondestructive testing. The purpose of the research and development is to address the shortcomings of classroom, remote digital learning, and laboratory practice listed in the article by developing a solution based on virtual reality technologies. The purpose stated lies in the pursuit of intensive solutions to the existing problems. Extensive development paths are not effective in improving the efficiency of training and checking students' knowledge in the context of the rapidly growing demand for nondestructive testing specialists. The concept of a digital twin as an educational resource is considered. The structural approach to the formation of complex educational resources both at the level of organization and at the level of digital product is presented. The structure of interrelationships between data in the formation of a digital twin of a radiographic image is presented. The results of the radiographic image simulation and its quality verification are shown. © 2024 IEEE.

关键词： Nondestructive examination

来源：评论

学校读者我要写书评

暂无评论

3D Modeling for a Flexible Detector in VR Radiography Simulator 7

3D Modeling for a Flexible Detector in VR Radiography Simula...

引用

7th International Conference on Information Technologies in engineering Education, Inforino 2024

作者： Kuvshinnikov, Vladimir Kovshov, Evgeny Korchagin, Valery Institute of Construction Technology - Atomstroy Research Laboratory of Digital Computer Systems and Automation JSC 'Research and Development' Moscow Russia Dmitry Mendeleev University of Chemical Technology of Russia Disruptive Engineering School of Chemical Engineering and Machinery Moscow Russia

ISBN: (纸本)9798350371369

Digital simulators based on virtual reality expand the range of educational opportunities and improve the quality of learning in various areas of knowledge through deeper "immersion"in the learning process. Attention to the details of the modeled process plays an important role. One of the tasks of interactive simulators is to provide an opportunity to see the relationship between the user's actions and the obtained qualitative and quantitative parameters and quality attributes of the simulated process result. Considered the issue of curved shape detectors application relevance in the practice of penetrating radiation evaluation in general and in industrial radiography in particular. The prerequisites for the creation of flexible (bendable) form of digital radiographic detectors and the features of two generations of practically implemented devices are analyzed. Development of a flexible detector digital twin is considered, models and algorithms for its realization in a virtual reality environment are proposed, and the main results of computational and laboratory experiments as well as the obtained radiographic images are presented. The main task of virtual reality technologies within the qualified technical specialists training programs is the development of their professional skills and the formation of stable behavior patterns that ensure strict compliance with the rules and requirements of industrial safety, thereby ensuring the high quality of the end product. © 2024 IEEE.

关键词： Virtual reality

来源：评论

学校读者我要写书评

暂无评论

Modelling information warfare dynamics to counter propaganda using a nonlinear differential equation with a PINN-based learning approach

引用

International Journal of Information Technology (Singapore) 2024年第3期16卷 1527-1538页

作者： Pandey, Rashmikiran Pandey, Mrinal Nazarov, Alexey Nikolaevich Department of Radio Engineering and Cybernetics Moscow Institute of Physics and Technology Moscow Russian Federation Federal Research Center Computer Science and Control Russian Academy of Science Moscow Russian Federation

The widespread dissemination of misinformation and propaganda has become a crucial issue in societal conversations. This study presents an innovative framework to counter propaganda within information warfare using a modified logistic differential equation integrated with a Physics-Informed Neural Network (PINN). Employing the LIAR dataset, which reflects real-world political discourse, our model captures the intricate dynamics of propaganda. The novel approach effectively estimates underlying dynamics and unknown parameters, yielding superior accuracy (97.32%) compared to benchmark models. A parameter sensitivity analysis reveals the significant impact of the spread rate parameter, shedding light on aggressive propaganda dissemination. This research paves the way for robust methods in combating propaganda, demonstrating the effectiveness and superiority of the proposed PINN-based model over established benchmark models. © 2023, The Author(s), under exclusive licence to Bharati Vidyapeeth's institute of computer Applications and Management.

关键词： Information warfare Nonlinear differential equations PINN Propaganda Random forest classifier TF-IDF

来源：评论

学校读者我要写书评

暂无评论

Technological Machines Diagnostics of Grain Processing Enterprises as the Object of automation

Technological Machines Diagnostics of Grain Processing Enter...

引用

2023 International Conference Automatics and Informatics, ICAI 2023

作者： Kalandarov, Palvan I. Ubaydullayeva, Shakhnoza R. Nikolov, Nikola N. Hayitov, Aziz Sharifov, Husen 'Tashkent Institute of Irrigation and Agricultural Mechanization Engineers' National Research University Department 'Automation and Control of Technology Process in Production' Tashkent Uzbekistan Technical University of Varna Faculty of Computer Science and Automation Department of Automation Varna Bulgaria Bukhara Institute of Natural Resource Management of the National Research University 'Tashkent Institute of Irrigation and Agricultural Mechanization Institute' Tashkent Uzbekistan

ISBN: (纸本)9798350312911

The article gives the basic concepts of reliability, performance, durability, considers the issues of changing the technical state of the machine during operation. The models under consideration have the ability to introduce various perturbations in order to simulate physical defects, and numerical simulation on a computer made it possible to obtain solutions in the form of temporary realizations of oscillations for different states of the simulation object. The cooperative use of the full-scale method and mathematical modeling made it possible to reduce the volume of full-scale experiments and apply statistical methods of analysis in the problem of classifying the technical condition by constructing mathematical models of the probability of failure and uptime during their operating time. The content of the main types of machine states is revealed, considerable attention is paid to the issues of identifying and influencing failures and the causes of failures in the machine, the reasons for the loss of performance during operation. © 2023 IEEE.

关键词： Deterioration

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：