检索结果-内蒙古大学图书馆

arXiv 2024年

作者： Cheng, Qing Guo, Jing Wang, Dong Department of Mathematics Tongji University Shanghai200092 China Key Laboratory of Intelligent Computing and Applications Tongji University Ministry of Education China School of Science and Engineering The Chinese University of Hong Kong Guangdong Shenzhen518172 China Shenzhen International Center for Industrial and Applied Mathematics Shenzhen Research Institute of Big Data Guangdong518172 China

In this paper, we consider numerical approximations for the optimal partition problem using Lagrange multipliers. By rewriting it into constrained gradient flows, three and four steps numerical schemes based on the Lagrange multiplier approach [16, 17] are proposed to solve the constrained gradient system. Numerical schemes proposed for the constrained gradient flows satisfy the nice properties of orthogonality-preserving, norm-preserving, positivity-preserving and energy dissipating. The proposed schemes are very efficient in which only linear Poisson equations are solved at each time step. Extensive numerical results in 2D and 3D for optimal partition problem are presented to validate the effectiveness and accuracy of the proposed numerical schemes. Copyright © 2024, The Authors. All rights reserved.

关键词： Lagrange multipliers

来源：评论

学校读者我要写书评

暂无评论

User Interaction Development for Radiotherapy Virtual Reality Training Application

User Interaction Development for Radiotherapy Virtual Realit...

引用

2023 IEEE International Conference on computing, ICOCO 2023

作者： Chan, Vei Siang Iglesias, Andres Mohamed, Farhan Salleh, Faezah M. Haron, Habibollah Jamaludin, Najwa Ayuni Galvez, Akemi Prada, Pedro J. Ruiz, Samuel You, Lihua Universiti Teknologi Malaysia Faculty of Computing Johor Bahru Malaysia Universidad de Cantabria Dept. of Applied Mathematics and Computational Sciences Santander Spain Toho University Faculty of Pharmaceutical Sciences Funabashi Japan Media and Game Innovation Center of Excellence Universiti Teknologi Malaysia Johor Bahru Malaysia Universiti Teknologi Malaysia Faculty of Science Johor Bahru Malaysia Hospital Universitario Marqués de Valdecilla Santander Spain National Center for Computer Animation Bournemouth University Poole United Kingdom

ISBN: (纸本)9798350302684

The advancement of virtual reality (VR) technology can enrich pedagogical approaches and information communication. In the oncology radiotherapy treatment, the medical practitioners revealed two main issues: the lack of training infrastructure and patient comprehension of the treatment process. Virtual simulation can assist in solving these complexities by offering an economical virtual embodiment of the medical facility. This study aims to improve the user interface and experience of VR training applications from previous work by conducting a domain expert intervention methodology. This paper discusses the main challenges and features of user interaction design for effective VR training systems and optimises the system based on feedback from domain experts. The authors anticipate that the key factors and design considerations proposed for this VR training application can benefit the development of related training systems in many other domains. © 2023 IEEE.

关键词： Virtual reality

来源：评论

学校读者我要写书评

暂无评论

IMPROVED DEEP LEARNING OF CHAOTIC DYNAMICAL SYSTEMS WITH MULTISTEP PENALTY LOSSES

arXiv

引用

arXiv 2024年

作者： Chakraborty, Dibyajyoti Chung, Seung Whan Chattopadhyay, Ashesh Maulik, Romit School of Information Sciences and Technology Pennsylvania State University University ParkPA16802 United States Center for Applied Scientific Computing Lawrence Livermore National Laboratory LivermoreCA94550 United States Department of Applied Mathematics University of California Santa Cruz 1156 High Street Santa CruzCA95064 United States

Predicting the long-term behavior of chaotic systems remains a formidable challenge due to their extreme sensitivity to initial conditions and the inherent limitations of traditional data-driven modeling approaches. This paper introduces a novel framework that addresses these challenges by leveraging the recently proposed multi-step penalty (MP) optimization technique. Our approach extends the applicability of MP optimization to a wide range of deep learning architectures, including Fourier Neural Operators and UNETs. By introducing penalized local discontinuities in the forecast trajectory, we effectively handle the non-convexity of loss landscapes commonly encountered in training neural networks for chaotic systems. We demonstrate the effectiveness of our method through its application to two challenging use-cases: the prediction of flow velocity evolution in two-dimensional turbulence and ocean dynamics using reanalysis data. Our results highlight the potential of this approach for accurate and stable long-term prediction of chaotic dynamics, paving the way for new advancements in data-driven modeling of complex natural phenomena. © 2024, CC BY-NC-SA.

关键词： Prediction models

来源：评论

学校读者我要写书评

暂无评论

Paired 2-Disjoint Path Covers of Burnt Pancake Graphs with Faulty Elements

SSRN

引用

SSRN 2024年

作者： Li, Pingshan Chen, Congzhen Liu, Xianglin Xiangtan University China School of Mathematics and Computational Science Xiangtan University Hunan Xiangtan411105 China Key Laboratory of Intelligent Computing & Information Processing of Education China Key Laboratory for Computation and Simulation in Science and Engineering China National Center for Applied Mathematics in Hunan China Guangxi Vocational University of Agriculture Guangxi Nanning530007 China

It is a key issue in parallel processing to find $k$-disjoint paths in the underlying graph of an interconnected network such that these disjoint paths pass through all vertices of the network, this is known as paired $k$-disjoint path cover problems or unpaired $k$-disjoint path cover problems. In 2024, Dvo\v{r}\'{a}k and Gu (Theoretical Computer Science, $986 (2024) 114327$) showed that there exist two disjoint paths whose vertices partition the vertex of the burnt pancake graph even if it contains at most $n-4$ faulty elements (vertices or edges) and they proposed an open problem: is it possible to improve the upper bound $n-4$ to $n-3$? In this paper, we provide a positive answer to this problem. © 2024, The Authors. All rights reserved.

关键词： Hamiltonians

来源：评论

学校读者我要写书评

暂无评论

A C0-continuous nonconforming virtual element method for linear strain gradient elasticity

arXiv

引用

arXiv 2024年

作者： Huang, Jianguo Yu, Yue School of Mathematical Sciences MOE-LSC Shanghai Jiao Tong University Shanghai200240 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education National Center for Applied Mathematics in Hunan School of Mathematics and Computational Science Xiangtan University Hunan Xiangtan411105 China

A robust C0-continuous nonconforming virtual element method (VEM) is developed for a boundary value problem arising from strain gradient elasticity in two dimensions, with the family of polygonal meshes satisfying a very general geometric assumption given in Brezzi et al. (2009) and Chen and Huang (2018). The stability condition of the VEMs is derived by establishing Korn-type inequalities and inverse inequalities. Some crucial commutative relations for locking-free analysis as in elastic problems are derived. The sharp and uniform error estimates with respect to both the microscopic parameter and the Lamé coefficient are achieved in the lowest-order case, which is also verified by numerical *** Codes 65N12, 65N15, 65N22, 65N30 © 2024, CC BY-NC-ND.

关键词： Boundary value problems

来源：评论

学校读者我要写书评

暂无评论

SCALABLE AND LOCALISED MODEL ORDER REDUCTION applied TO COMPOSITE AERO-STRUCTURES 20

SCALABLE AND LOCALISED MODEL ORDER REDUCTION APPLIED TO COMP...

引用

20th European Conference on Composite Materials: Composites Meet Sustainability, ECCM 2022

作者： Bénézech, Jean Seelinger, Linus Bastian, Peter Dodwell, Tim Butler, Richard Scheichl, Robert Material and Structure Research Centre University of Bath Bath United Kingdom Institute for Applied Mathematics Heidelberg University Heidelberg Germany Interdisciplinary Center for Scientific Computing Heidelberg University Heidelberg Germany Institute of Data Science and Ai University of Exeter Exeter United Kingdom Alan Turing Institute The British Library London United Kingdom

ISBN: (纸本)9782970161400

Due to the interaction of structural meso-scale and geometric macro-scale features, composite aero-structures are inherently multi-scale in nature. In addition, complex manufacturing processes lead to the appearance of defects at multiple scales. These defects bring extra dimensions to the multi-scale problem which discourage the use of a scale separation hypothesis. Despite the growing knowledge of the types of composite characteristic defects, for large scale aerostructures, their location and exact geometry remain unknown or are only observable with difficulty. Hence, a large-scale uncertainty quantification (UQ) problem must be solved. The primary challenge is the cost of the associated numerical simulation. Therefore, to tackle this problem, an efficient multiscale generalized finite element (FE) method has been developed within the open-source software package DUNE (https://***/). Thanks to its modularity, our method has been integrated into an Offline/Online framework allowing a very efficient exploration of defects in of the material parameters. ©2022 Bénézech et al.

关键词： Defects

来源：评论

学校读者我要写书评

暂无评论

Strong Current in Carbon Nanoconductors: Mechanical and Magnetic Stability

SSRN

引用

SSRN 2024年

作者： Brandbyge, Mads Leitherer, Susanne Papior, Nick Department of Chemistry University of Copenhagen CopenhagenDK-2100 Denmark DTU Computing Center Department of Applied Mathematics and Computer Science Technical University of Denmark Kongens LyngbyDK-2800 Denmark Department of Physics Technical University of Denmark Kongens LyngbyDK-2800 Denmark

Carbon nanoconductors are known to have extraordinary mechanical strength and interestingmagnetic properties. Moreover, nanoconductors based on one- or two-dimensional carbon allotropesdisplay a very high current-carrying capacity and ballistic transport. Here, we employa recent, simple approach based on density functional theory to analyze the impact of strongcurrent on the mechanical and magnetic properties of carbon nanoconductors. We find that theinfluence of the current itself on the bond-strength of carbon in general is remarkably low comparedto e.g. typical metals. This is demonstrated for carbon chains, carbon nanotubes, grapheneand polyacetylene. We can trace this to the strong binding and electronic bandstructure. On theother hand, we find that the current significanly change the magnetic properties. In particular, wefind that currents in graphene zig-zag edge states quench the magnetism. © 2024, The Authors. All rights reserved.

关键词： Density functional theory

来源：评论

学校读者我要写书评

暂无评论

Lattice Boltzmann Simulation of Magnetic Field Effect on Electrically Conducting Fluid at Inclined Angles in Rayleigh-Bénard Convection

引用

Energy Engineering 2021年第1期118卷 15-36页

作者： T.Ahmed S.Hassan M.F.Hasan M.M.Molla M.A.Taher S.C.Saha Department of Mathematics and Physics North South UniversityDhaka1229Bangladesh Center for Applied Scientific Computing(CASC) North South UniversityDhaka1229Bangladesh Department of Engineering&Physical Sciences La Trobe UniversityMelbourneVIC 3086Australia Department of Mathematics Dhaka University of Science and TechnologyGazipurBangladesh School of Mechanical and Mechatronic Engineering University of Technology SydneyUltimoAustralia

The magneto-hydrodynamics(MHD)effect is studied at different inclined angles in Rayleigh-Bénard(RB)convection inside a rectangular enclosure using the lattice Boltzmann method(LBM).The enclosure is filled with electrically conducting fluids of different *** characteristics are defined by Prandtl number,*** considered Pr values for this study are 10 and *** influence of other dimensionless parameters Rayleigh numbers Ra=10^(3);10^(4);10^(5);10^(6) and Hartmann numbers Ha=0,10,25,50,100,on fluid flow and heat transfer,are also investigated considering different inclined anglesφof magnetic field by analyzing computed local Nusselt numbers and average Nusselt *** results of the study show the undoubted prediction capability of LBM for the current *** simulated results demonstrate that the augmentation in heat transfer is directly related to Ra values,but it is opposite while observing the characteristics of Ha ***,it is also found thatφhas a significant impact on heat transfer for different ***,isotherms are found to be always parallel to the horizontal axis at Ra=10^(3) as conduction overcomes the convection in the heat transfer,but this behaviour is not seen at Ra=10^(4) when Ha>***,at Ra=10^(6),oscillatory instability appears but LBM is still able to provide a complete map of this predicted beha*** appropriate validation with previous numerical studies demonstrates the accuracy of the present approach.

关键词： Average rate of heat transfer Hartmann number lattice Boltzmann method magnetic field effect Rayleigh-Bernard convection

来源：评论

学校读者我要写书评

暂无评论

Strong current in carbon nanoconductors: Mechanical and magnetic stability

arXiv

引用

arXiv 2024年

作者： Leitherer, Susanne Papior, Nick R. Brandbyge, Mads Department of Chemistry University of Copenhagen CopenhagenDK-2100 Denmark DTU Computing Center Department of Applied Mathematics and Computer Science Technical University of Denmark Kongens LyngbyDK-2800 Denmark Department of Physics Technical University of Denmark Kongens LyngbyDK-2800 Denmark

Carbon nanoconductors are known to have extraordinary mechanical strength and interesting magnetic properties. Moreover, nanoconductors based on one- or two-dimensional carbon allotropes display a very high current-carrying capacity and ballistic transport. Here, we employ a recent, simple approach based on density functional theory to analyze the impact of strong current on the mechanical and magnetic properties of carbon nanoconductors. We find that the influence of the current itself on the bond-strength of carbon in general is remarkably low compared to e.g. typical metals. This is demonstrated for carbon chains, carbon nanotubes, graphene and polyacetylene. We can trace this to the strong binding and electronic bandstructure. On the other hand, we find that the current significanly change the magnetic properties. In particular, we find that currents in graphene zig-zag edge states quench the magnetism. © 2024, CC BY.

关键词： Magnetic properties

来源：评论

学校读者我要写书评

暂无评论

Boundary layer challenges: A comparative analysis of two efficient meshless approaches

引用

Partial Differential Equations in applied mathematics 2024年 10卷

作者： Alshammari, Abdulrahman Obaid Khan, Muhammad Nawaz Ahmad, Imtiaz Department of Mathematics College of Science Jouf University Sakaka 72388 Saudi Arabia Mathematics in Applied Sciences and Engineering Research Group Scientific Research Center Al-Ayen University Nasiriyah 64001 Iraq Institute of Informatics and Computing in Energy (IICE) Universiti Tenaga Nasional Kajang Selangor Malaysia

This article presents two meshless computational techniques: the radial basis function (RBF) method and the polynomial method, for numerically analyzing boundary layer problems, with a specific focus on singularly perturbed two-point boundary value problems. Both of these suggested meshless methods offer an advantage over globally supported meshless techniques, as they involve approximating derivatives by employing a constrained set of nodes located in the neighborhood of each collocation node. As a result, they demand significantly reduced computational effort compared to the globally supported collocation method. To assess the accuracy of these methods, we employ the maximum error norm, and the results are presented in the form of tables and graphs. The simulation results demonstrate that both approaches exhibit robust performance in addressing the investigated boundary layer problems. © 2024 The Author(s)

关键词： Boundary layer problems Meshless computational techniques Polynomial method Radial basis function method

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：