检索结果-内蒙古大学图书馆

Correction of High-Order Lk Approximation for Subdiffusion

Journal of Scientific Computing 2022年第1期93卷 31-31页

作者： Shi, Jiankang Chen, Minghua Yan, Yubin Cao, Jianxiong School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex Systems Lanzhou University Lanzhou730000 China Department of Physical Mathematical and Engineering Faculty of Science and Engineering University of Chester Parkgate Road ChesterCh14BJ United Kingdom School of Sciences Lanzhou University of Technology Lanzhou730000 China

The subdiffusion equations with a Caputo fractional derivative of order α∈(0,1) arise in a wide variety of practical problems, which describe the transport processes, in the force-free limit, slower than Brownian diffusion. In this work, we derive the correction schemes of the Lagrange interpolation with degree k (k≤6) convolution quadrature, called Lk approximation, for the subdiffusion. The key step of designing correction algorithm is to calculate the explicit form of the coefficients of Lk approximation by the polylogarithm function or Bose-Einstein integral. To construct a τ8 approximation of Bose-Einstein integral, the desired (k+1-α)th-order convergence rate can be proved for the correction Lk scheme with nonsmooth data, which is higher than kth-order BDFk method in [Jin, Li, and Zhou, SIAM J. Sci. Comput., 39 (2017), A3129–A3152;Shi and Chen, J. Sci. Comput., (2020) 85:28]. The numerical experiments with spectral method are given to illustrate theoretical results. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2022. Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s);author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

关键词： Statistical mechanics

来源：评论

学校读者我要写书评

暂无评论

Influence of Asymmetric Pre-Whirl Stator Spacing on Unsteady Characteristics of Pump-Jet Propulsor

SSRN

引用

SSRN 2022年

作者： Li, Fuzheng Liu, Guanshan Huang, Qiao-Gao Sun, Guocang Pan, Guang Qin, Denghui Key Laboratory of Unmanned Underwater Vehicle School of Marine Science and Technology Northwestern Polytechnical University Xi’an710072 China CSSC Systems Engineerings Research Institute Beijing100000 China Wuhan Second Ship Design and Research Institute Wuhan430205 China State Key Laboratory of Turbulence and Complex Systems Department of Aeronautics and Astronautics College of Engineering Peking University Beijing100871 China

This work studies the effect of the asymmetric pre-whirl stator spacing on the hydrodynamic performance of a pump-jet propulsor (PJP). The PJP contains a 13-stator and 7-rotor. The stator count is altered in the upper and lower half, and the total count is held constant. Results show that the steady performance is independent of the stator non-uniformity at design conditions. While the unsteady fluctuation of the rotor force and flow field is deeply affected by this adjustment. The cause is that the different incident angles of each rotor resulted from various stator spacing. The larger the stator count on one side, the great the incident angle in the corresponding location. Eventually, the stator root vortices in the lower half, where stator count is relatively larger, are weakened, whereas the tip vortex shape and intensity are not affected by the stator non-uniformity. Most notably, the PJP with a slight change of stator arrangement, in which the difference between two half parts is one, does not cause a significant change in flow, and the thrust amplitude at specific frequency decreases by 40% compared to the uniform stator case. © 2022, The Authors. All rights reserved.

关键词： Stators

来源：评论

学校读者我要写书评

暂无评论

A Subspace-Based Non-Dominated Subset Selection Method

A Subspace-Based Non-Dominated Subset Selection Method

引用

Congress on Evolutionary Computation

作者： Qingshan Tan Changhe Li Sanyou Zeng Shengxiang Yang School of Automation China University of Geosciences Wuhan China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Engineering Research Center of Intelligent Technology for Geo-Exploration Ministry of Education Wuhan China School of Mechanical Engineering and Electronic Information China University of Geosciences Wuhan China School of Computer Science and Informatics De Montfort University Leicester United Kingdom

Environmental selection is an important process in multi-objective evolutionary algorithms (MOEAs). As the evolution progresses, the number of non-dominated solutions increases. This paper is focused on selecting a subset from excess non-dominated solutions for evolutionary or the final output. However, traditional selection methods in classical MOEAs encounter difficulties when dealing with candidate solutions that possess irregular topologies. Although the distance-based subset selection methods are not sensitive to the topologies of the candidate points, they have significant room for reducing computational complexity. In order to address the above issues, a subspace selection method is proposed in this paper. It partitions the objective space into multiple subspaces that have comparable volumes and shapes. The maximal minimum distance of each solution is considered to ensure that the sparsest solution is always chosen first. To save computational costs, only the solutions in the neighboring subspaces are taken into account. The experimental results demonstrate that the proposed subspace selection method outperforms classical selection methods in solving problems with various shapes of the Pareto front.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Stochastic Event-triggered Variational Bayesian Filtering

arXiv

引用

arXiv 2022年

作者： Lv, Xiaoxu Duan, Peihu Duan, Zhisheng Chen, Guanrong Shi, Ling The State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering Science College of Engineering Peking University Beijing100871 China Department of Electrical Engineering City University of Hong Kong Hong Kong Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong

This paper proposes an event-triggered variational Bayesian filter for remote state estimation with unknown and time-varying noise covariances. After presetting multiple nominal process noise covariances and an initial measurement noise covariance, a variational Bayesian method and a fixed-point iteration method are utilized to jointly estimate the posterior state vector and the unknown noise covariances under a stochastic event-triggered mechanism. The proposed algorithm ensures low communication loads and excellent estimation performances for a wide range of unknown noise covariances. Finally, the performance of the proposed algorithm is demonstrated by tracking simulations of a vehicle. Copyright © 2022, The Authors. All rights reserved.

关键词： Kalman filters

来源：评论

学校读者我要写书评

暂无评论

Applying Predictive Machine Learning Algorithms to Petroleum Refining Processes as Part of Intelligent Automation

Applying Predictive Machine Learning Algorithms to Petroleum...

引用

Annual Siberian Russian Workshop on Electron Devices and Materials (EDM)

作者： Ivan S. Nekrasov Vadim S. Tynchenko Vladimir B. Bukhtoyarov Vera A. Kachaeva Kirill A. Bashmur Aleksandra E. Sinitskaya Laboratory of Biofuel Composition Siberian Federal Univercity Krasnoyarsk Russian Federation dept. of Technological Machines and Equipment of Oil and Gas Complex Siberian Federal Univercity Krasnoyarsk Russian Federation Information-Control Systems Department Institute of Computer Science and Telecommunications Reshetnev Siberian State University of Science and Technology Krasnoyarsk Russian Federation

ISBN: (数字)9781665498043

ISBN: (纸本)9781665498050

Intelligent automation is a term that can be applied to the more complex field of workflow automation, consisting of robotic workplace automation, robotic process automation, machine learning, and artificial intelligence. Depending on the type of business, companies often use one or more types of automation to improve efficiency or effectiveness. As you move from process-driven automation to more flexible data-driven automation, additional costs arise in the form of training datasets, technical development, infrastructure, and expertise. But the potential benefits in terms of new ideas and financial development can increase significantly. The development of mechanized oil production in recent years has been accompanied by significant achievements in the field of digitalization. Machine learning, as an important element of digitalization, can successfully solve many production problems. The paper describes the application of some machine learning algorithms for solving the problem of classifying and predicting failures of hydrocracking process equipment that occur during oil refining and diesel fuel production. The application of random forest, principal component analysis and hyperparameter tuning methods is considered. The effectiveness of their application is compared.

关键词： Radio frequency Intelligent automation Machine learning algorithms Biological system modeling Oils Refining Production

来源：评论

学校读者我要写书评

暂无评论

Privacy-Preserving Brain-Computer Interfaces: A Systematic Review

arXiv

引用

arXiv 2024年

作者： Xia, Kun Duch, Wlodzislaw Sun, Yu Xu, Kedi Fang, Weili Luo, Hanbin Zhang, Yi Sang, Dong Xu, Xiaodong Wang, Fei-Yue Wu, Dongrui The Ministry of Education Key Laboratory of Image Processing and Intelligent Control School of Artificial Intelligence and Automation Huazhong University of Science and Technology Wuhan430074 China Zhejiang Lab Hangzhou311121 China The Department of Informatics School of Physics Astronomy and Informatics Neurocognitive Laboratory Center for Modern Interdisciplinary Technologies Nicolaus Copernicus University Torun Poland The Ministry of Education Key Laboratory for Biomedical Engineering Zhejiang University Hangzhou China The Zhejiang University School of Medicine National Clinical Research Center for Child Health Hangzhou China Department of Biomedical Engineering Zhejiang University Hangzhou China The School of Civil and Hydraulic Engineering Huazhong University of Science and Technology Wuhan430074 China The College of Public Administration Huazhong University of Science and Technology Wuhan430074 China The NetsUnion Clearing Corporation Beijing100045 China The State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing100049 China

A brain-computer interface (BCI) establishes a direct communication pathway between the human brain and a computer. It has been widely used in medical diagnosis, rehabilitation, education, entertainment, etc. Most research so far focuses on making BCIs more accurate and reliable, but much less attention has been paid to their privacy. Developing a commercial BCI system usually requires close collaborations among multiple organizations, e.g., hospitals, universities, and/or companies. Input data in BCIs, e.g., electroencephalogram (EEG), contain rich privacy information, and the developed machine learning model is usually proprietary. Data and model transmission among different parties may incur significant privacy threats, and hence privacy protection in BCIs must be considered. Unfortunately, there does not exist any contemporary and comprehensive review on privacy-preserving BCIs. This paper fills this gap, by describing potential privacy threats and protection strategies in BCIs. It also points out several challenges and future research directions in developing privacy-preserving BCIs. © 2024, CC BY.

关键词： Differential privacy

来源：评论

学校读者我要写书评

暂无评论

A Novel Visual Perception Framework for Unmanned Aerial Vehicles: Challenges and Approaches

A Novel Visual Perception Framework for Unmanned Aerial Vehi...

引用

Chinese Automation Congress (CAC)

作者： Xuan Li Haibin Duan Hong Mo Fei-Yue Wang Peng Cheng Laboratory Shenzhen China The State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical Engineering Beihang University Beijing China The School of Electrical and Information Engineering Changsha University of Science and Technology Changsha China The State Key Laboratory for Management and Control of Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781665426480

Change detection (CD) is an important preprocessing process in visual perception. Due to the difficulties of collection and labeling images in water scnens, the design and validation of the change detection algorithm is more difficult than expected. In this paper, we present a novel visual perception framework based on parallel vision for unmanned aerial vehicle (UAV). The visual perception framework consists of artificial scenes, computational experiments and parallel execution. In artificial scenes, we construct a water scene and automatically generated pixel-level image annotation. Next, computational experiments are carried out on different domain dataset. The experiment results show that: 1) mixed images effectively improve the performance of change detection model; 2) domain shift problems still greatly affect the algorithm performance.

关键词： Automation Change detection algorithms Computational modeling Image annotation Autonomous aerial vehicles Labeling Detection algorithms

来源：评论

学校读者我要写书评

暂无评论

Learning to Manipulate Tools Using Deep Reinforcement Learning and Anchor Information

Learning to Manipulate Tools Using Deep Reinforcement Learni...

引用

IEEE International Conference on Robotics and Biomimetics

作者： Junhang Wei Shaowei Cui Peng Hao Shuo Wang School of Future Technology University of Chinese Academy of Sciences Beijing China State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing China University of Chinese Academy of Sciences Beijing China Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences Shanghai China

ISBN: (纸本)9781665481106

Endowing robots with tool manipulation skills helps them accomplish challenging tasks. While robots manipulate tools to achieve goals, the alignment of tools and targets is a noise-sensitive and contact-rich task. However, it is difficult to access the accurate pose of the tool and the target. When there is unknown noise in the observations, reinforcement learning can't be sure to perform well. In this paper, we define the easier-to-obtain accurate task-related information as anchor information and introduce a tool manipulation method based on reinforcement learning and anchor information, which can perform well when the observations include unknown noise. To evaluate the method, we build a simulated environment ToolGym, which includes four different kinds of tools and different noise sampling functions for each tool. Finally, we compare our method with baseline methods to show the effectiveness of the proposed method.

关键词： Deep learning Biomimetics Reinforcement learning Grasping Fasteners End effectors Task analysis

来源：评论

学校读者我要写书评

暂无评论

Advances in coatings on biodegradable magnesium alloys

引用

Journal of Magnesium and Alloys 2020年第1期8卷 42-65页

作者： Zheng-Zheng Yin Wei-Chen Qi Rong-Chang Zeng Xiao-Bo Chen Chang-Dong Gu Shao-Kang Guan Yu-Feng Zheng Corrosion Laboratory for Light Metals College of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266590China Department of Orthopaedics and Traumatology Li KaShing Faculty of MedicineThe University of Hong KongHong Kong 999077China School of Engineering RMIT UniversityCarltonVIC 3053Australia School of Materials Science and Engineering State Key Laboratory of Silicon MaterialsZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450002China State Key Laboratory for Turbulence and Complex Systems and Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China

The clinic applications of bioabsorbable magnesium(Mg)and its alloys have been significantly restricted owing to their poor corrosion *** elemental alloying,surface modification and functionality is a major approach to increasing corrosion resistance for magnesium *** article reviews the cutting-edge advances and progress of biodegradable surface coatings upon Mg alloys over the last decades,aims to build up a knowledge framework of surface modification on biodegradable Mg alloys.A considerable number of conversion,deposition,mechanical and functional coatings and their preparation methods are *** emphasis has been placed on the composition of chemical conversion and deposited coatings to overcome the disadvantages of adhesion,corrosion resistance and biocompatibility of a single coating for biomedical *** issues have been addressed on the integration of the structural and functional factors of the composite coatings.

关键词： Magnesium alloy Biomaterial Corrosion resistance Coating Biodegradability

来源：评论

学校读者我要写书评

暂无评论

Structural insights into human Pol III transcription initiation in action

引用

Nature 2025年 1-8页

作者： Wang, Qianmin Ren, Yulei Jin, Qianwei Chen, Xizi Xu, Yanhui Fudan University Shanghai Cancer Center Institutes of Biomedical Sciences New Cornerstone Science Laboratory State Key Laboratory of Genetics and Development of Complex Phenotypes Department of Biochemistry and Biophysics School of Life Sciences Shanghai Key Laboratory of Radiation Oncology and Shanghai Key Laboratory of Medical Epigenetics Shanghai Medical College of Fudan University Shanghai China Sycamore Research Institute of Life Sciences Shanghai China Greater Bay Area Institute of Precision Medicine (Guangzhou) Fudan University Guangzhou China The International Co-laboratory of Medical Epigenetics and Metabolism Ministry of Science and Technology China Department of Systems Biology for Medicine School of Basic Medical Sciences Shanghai Medical College of Fudan University Shanghai China

RNA polymerase III (Pol III) transcribes highly demanded RNAs grouped into three types of classical promoters, including type 1 (5S rRNA), type 2 (tRNA) and type 3 (short non-coding RNAs, such as U6, 7SK and RNase H1) promoters^{1, 2, 3, 4, 5, 6–7}. While structures of the Pol III preinitiation complex (PIC)^{8, 9, 10–11} and elongation complex (EC)^{12, 13, 14, 15–16} have been determined, the mechanism underlying the transition from initiation to elongation remains unclear. Here we reconstituted seven human Pol III transcribing complexes (TC4, TC5, TC6, TC8, TC10, TC12 and TC13) halted on U6 promoters with nascent RNAs of 4–13 nucleotides. Cryo-electron microscopy structures captured initially transcribing complexes (ITCs;TC4 and TC5) and ECs (TC6–13). Together with KMnO₄ footprinting, the data reveal extensive modular rearrangements: the transcription bubble expands from PIC to TC5, followed by general transcription factor (GTF) dissociation and abrupt bubble collapse from TC5 to TC6, marking the ITC–EC transition. In TC5, SNAPc and TFIIIB remain bound to the promoter and Pol III, while the RNA–DNA hybrid adopts a tilted conformation with template DNA blocked by BRF2, a TFIIIB subunit. Hybrid forward translocation during ITC–EC transition triggers BRF2-finger retraction, GTF release and transcription-bubble collapse. Pol III then escapes the promoter while GTFs stay bound upstream, potentially enabling reinitiation. These findings reveal molecular insights into Pol III dynamics and reinitiation mechanisms on type 3 promoters of highly demanded small RNAs, with the earliest documented initiation–elongation transition for an RNA polymerase. © The Author(s), under exclusive licence to Springer Nature Limited 2025.

关键词：

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：