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光的衍射的理论分析及Mathematica仿真模拟 被引量:7
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作者 陈学文 罗源源 +1 位作者 张家伟 姚雪 《西南师范大学学报(自然科学版)》 CAS 北大核心 2018年第11期156-161,共6页
首先利用旋转矢量从理论上推出了光的多缝干涉的光强分布公式,并将狭缝数N→!,从而得到光的单缝衍射光强分布,进而在多缝干涉和单缝衍射的基础上得到了光栅衍射光强分布.此外,将Mathematica仿真模拟应用到光的衍射课堂教学中.基于Mathem... 首先利用旋转矢量从理论上推出了光的多缝干涉的光强分布公式,并将狭缝数N→!,从而得到光的单缝衍射光强分布,进而在多缝干涉和单缝衍射的基础上得到了光栅衍射光强分布.此外,将Mathematica仿真模拟应用到光的衍射课堂教学中.基于Mathematica软件的交互功能,利用Mathematica的Manipulate命令对单缝夫琅禾费衍射和光栅衍射做了仿真模拟,获得了相应的可以调节各参数(如波长、狭缝宽度、光栅常数等)的动态图形.这对学生建立清晰的物理图像,更好地理解光的衍射的物理规律有很好的促进作用. 展开更多
关键词 光的衍射 旋转矢量 MATHEMATICA 虚拟仿真
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Mathematical Model of the Spread of the Coronavirus Disease 2019 (COVID-19) in Burkina Faso
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作者 Aboudramane Guiro Blaise Koné Stanislas Ouaro 《Applied Mathematics》 2020年第11期1204-1218,共15页
In this paper, we develop a mathematical model of the COVID-19 pandemic in Burkina Faso. We use real data from Burkina Faso National Health Commission against COVID-19 to predict the dynamic of the disease and also th... In this paper, we develop a mathematical model of the COVID-19 pandemic in Burkina Faso. We use real data from Burkina Faso National Health Commission against COVID-19 to predict the dynamic of the disease and also the cumulative number of reported cases. We use public policies in model in order to reduce the contact rate, this allows to show how the reduction of the daily report of infectious cases goes, so we would like to draw the attention of decision makers for a rapid treatment of reported cases. 展开更多
关键词 COVID-19 STATISTICS Data Exposed Person Reported and Unreported Cases Mathematical Model Public Policies Basic Reproduction Number Prediction
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MathWorks推出与机器人操作系统(ROS)完整集成的Robotics System Toolbox
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《微型机与应用》 2015年第9期70-70,共1页
Math Works近日推出Robotics System Toolbox(机器人系统工具箱),这个新产品是Release 2015a的组成部分。、通过即用型算法和用于开发自动移动机器人应用程序的硬件连接性,Robotics System Toolbox提供了常用的机器人算法,以及MAT... Math Works近日推出Robotics System Toolbox(机器人系统工具箱),这个新产品是Release 2015a的组成部分。、通过即用型算法和用于开发自动移动机器人应用程序的硬件连接性,Robotics System Toolbox提供了常用的机器人算法,以及MATLAB和Simulink与机器人操作系统(ROS)之间的接口和集成。现在,机器人研究人员和工程师们可以在单个统一的设计环境中开发机器人算法,在支持ROS的机器人和机器人仿真器(如Gazebo和V—REP)上测试和部署机器人算法。它通过减少从MATLAB程序转换到ROS程序所需的手动修改时间,留出了更多的时间来测试和调试算法。 展开更多
关键词 TOOLBOX 机器人系统 MATH 操作系统 集成 Simulink MATLAB Release
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A mathematical perspective on the determination of coastal peopling nuclei
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作者 Claude Gauthier Ahcène Brahmi Ghislain Vautour 《Natural Science》 2013年第1期15-21,共7页
Two versions of a mathematical model are proposed for the process underlying the choice of settlement sites of past, present and future populations along the world coastline. The model is primarily based on the geomet... Two versions of a mathematical model are proposed for the process underlying the choice of settlement sites of past, present and future populations along the world coastline. The model is primarily based on the geometry of coastline at the scale of the map representing the region under study. It can be used to determine sites of human occupation for archaeological interest, as well as to plan future movements of present coastal populations due to the current sea level rise. Two examples related to history are presented: the first applies to the coastal peopling of the Mediterranean region, and the second to the settlement of Acadians in North-East of the Canadian province of New Brunswick in the second half of the 18th century. 展开更多
关键词 MATHEMATICAL MODELING COASTAL
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A Mathematical Model of COVID-19: Analysis and Identification of Parameters for Better Decision Making
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作者 Ouaténi Diallo Yaya Kone +2 位作者 Chata Sanogo Jérô me Pousin 《Applied Mathematics》 2022年第2期205-214,共10页
Since the onset of the COVID-19 epidemic, the world has been impressed by two things: The number of people infected and the number of deaths. Here, we propose a mathematical model of the spread of this disease, analyz... Since the onset of the COVID-19 epidemic, the world has been impressed by two things: The number of people infected and the number of deaths. Here, we propose a mathematical model of the spread of this disease, analyze this model mathematically and determine one or more dominant factors in the propagation of the COVID-19 epidemic. We consider the S-E-I-R epidemic model in the form of ordinary differential equations, in a population structured in susceptibles S, exposed E as caregivers, travelers and assistants at public events, infected I and recovered R classes. Here we decompose the recovered class into two classes: The deaths class D and the class of those who are truly healed H. After the model construction, we have calculated the basic reproduction number R<sub>0</sub>, which is a function of certain number of parameters like the size of the exposed class E. In our paper, the mathematical analysis, which consists in searching the equilibrium points and studying their stability, is done. The work identifies some parameters on which one can act to control the spread of the disease. The numerical simulations are done and they illustrate our theoretical analysis. 展开更多
关键词 COVID-19 Mathematical Model R0 SPREAD Control Parameters Malian Data
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Mathematical Model of Dynamics of Micropolar Orthotropic Elastic Thin Bars with Free Fields of Displacements and Rotations
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作者 Sargsyan Samvel Margaryan Lilit 《Journal of Mechanics Engineering and Automation》 2012年第2期110-118,共9页
In the present paper, initial-boundary value problem of plane stress state of micropolar theory of elasticity is considered for orthotropic material in the domain of thin rectangle. General hypotheses are formulated, ... In the present paper, initial-boundary value problem of plane stress state of micropolar theory of elasticity is considered for orthotropic material in the domain of thin rectangle. General hypotheses are formulated, which are the qualitative results of the asymptotic method of integration of the stated initial-boundary value problem. On the basis of the accepted hypotheses general applied one-dimensional models of dynamics of bending deformation of micropolar orthotropic elastic thin bars with free fields of displacements and rotations are constructed with and without consideration of shear deformations. With the help of the constructed models different dynamic problems of micropolar bars can be studied. Here concrete problems of free and forced vibrations of hinged supported micropolar orthotropic elastic thin bar are studied. Numerical analysis is done and specific features of dynamic characteristics of micropolar material are revealed. Particularly, it is shown that there is a frequency of vibrations of the micropolar bar that does not depend on bar sizes. 展开更多
关键词 DYNAMICS MICROPOLAR ORTHOTROPIC mathematical model free and forced vibrations.
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GLOBAL BIFURCATION AND CHAOS IN A VAN DER POL-DUFFING-MATHIUE SYSTEM WITH A SINGLE-WELL POTENTIAL OSCILLATOR 被引量:1
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作者 Xu, J Wang, C +1 位作者 Chen, YS Lu, QS 《Acta Mechanica Solida Sinica》 SCIE EI 1997年第3期262-275,共14页
The global bifurcation and chaos are investigated in this paper for a van der Pol-Duffing-Mathieu system with a single-well potential oscillator by means of nonlinear dynamics. The autonomous system corresponding to t... The global bifurcation and chaos are investigated in this paper for a van der Pol-Duffing-Mathieu system with a single-well potential oscillator by means of nonlinear dynamics. The autonomous system corresponding to the system under discussion is analytically studied to draw all global bifurcation diagrams in every parameter space. These diagrams are called basic bifurcation ones. Then fixing parameter in every space and taking the parametrically excited amplitude as a bifurcation parameter, we can observe how to evolve from a basic bifurcation diagram to a chaos pattern in terms of numerical methods. The results are sufficient to show that the system has distinct dynamic behavior. Finally, the properties of the basins of attraction are observed and the appearance of fractal basin boundaries heralding the onset of a loss of structural integrity is noted in order to consider how to control the extent and the rate of the erosion in the next paper. 展开更多
关键词 global bifurcation CHAOS nonlinear vibration basin FRACTAL
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Applying a Mathematical Model to the Performance of a Female Monofin Swimmer 被引量:1
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作者 Elisée Gouba Balira Ousmane Konfe +2 位作者 Ousseynou Nakoulima Blaise Some Olivier Hue 《Applied Mathematics》 2013年第12期1673-1681,共9页
This study sought to determine the best method to quantify training based on heart rate data. It proposes a modification of Banister’s original performance model to improve the accuracy of predicted performance. The ... This study sought to determine the best method to quantify training based on heart rate data. It proposes a modification of Banister’s original performance model to improve the accuracy of predicted performance. The new formulation introduces a variable that accounts for changes in the subject’s initial performance as a result of the quantity of training. The two systems models were applied to a well-trained female monofin swimmer over a 24-week training period. Each model comprised a set of parameters unique to the individual and was estimated by fitting model-predicted performance to measured performance. We used the Alienor method associated to Optimization-Preserving Operators to identify these parameters. The quantification method based on training intensity zones gave a better estimation of predicted performance in both models. Using the new model in sports in which performance is generally predicted (running, swimming) will help us to define its real interest. 展开更多
关键词 TRAINING Quantification Banister’s MODEL
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SIEMENS AUTOMATION和MATHWORKS在仿真与基于模型的设计方面展开协作
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《微型机与应用》 2015年第1期96-96,共1页
MathWorks近日宣布,与Siemens Automation Systems拓展关系,使客户能够更加方便地利用基于模型的设计来开发和实施复杂的控制算法。控制工程师们现在可以从Simulink生成代码,然后将其部署到SiemensSIMATICS7模块化PLC控制器和SIMATIC... MathWorks近日宣布,与Siemens Automation Systems拓展关系,使客户能够更加方便地利用基于模型的设计来开发和实施复杂的控制算法。控制工程师们现在可以从Simulink生成代码,然后将其部署到SiemensSIMATICS7模块化PLC控制器和SIMATICWinACRTX软件控制器。因此,在PLC硬件上执行进一步验证前,可以使用仿真来设计和测试高级控制策略以证明概念的可行性。为了支持这一集成,SiemensAutomationSystems还加入了MathWorksConnectionsProgram。 展开更多
关键词 AUTOMATION 基于模型 SIEMENS 设计 仿真 AUTOMATION PLC控制器 SIMULINK
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Automated classification technique for edge-on galaxies based on mathematical treatment of brightness data
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作者 Mohamed Eassa Ibrahim Mohamed Selim +1 位作者 Walid Dabour Passent Elkafrawy 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第10期231-238,共8页
Classification of edge-on galaxies is important to astronomical studies due to our Milky Way galaxy being an edge-on galaxy.Edge-on galaxies pose a problem to classification due to their less overall brightness levels... Classification of edge-on galaxies is important to astronomical studies due to our Milky Way galaxy being an edge-on galaxy.Edge-on galaxies pose a problem to classification due to their less overall brightness levels and smaller numbers of pixels.In the current work,a novel technique for the classification of edge-on galaxies has been developed.This technique is based on the mathematical treatment of galaxy brightness data from their images.A special treatment for galaxies’brightness data is developed to enhance faint galaxies and eliminate adverse effects of high brightness backgrounds as well as adverse effects of background bright stars.A novel slimness weighting factor is developed to classify edge-on galaxies based on their slimness.The technique has the capacity to be optimized for different catalogs with different brightness levels.In the current work,the developed technique is optimized for the EFIGI catalog and is trained using a set of 1800 galaxies from this catalog.Upon classification of the full set of 4458 galaxies from the EFIGI catalog,an accuracy of 97.5% has been achieved,with an average processing time of about 0.26 seconds per galaxy on an average laptop. 展开更多
关键词 techniques:image processing methods:data analysis galaxies:formation
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Erratum to “Manifolds with Bakry-Emery Ricci Curvature Bounded Below”, Advances in Pure Mathematics, Vol. 6 (2016), 754-764
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作者 Issa Allassane Kaboye Bazanfaré Mahaman 《Advances in Pure Mathematics》 2017年第11期647-648,共2页
The original online version of this article (Issa Allassane Kaboye, Bazanfaré Mahaman (2016) Manifolds with Bakry-Emery Ricci Curvature bounded below 6, 754-764. http://dx.doi.org/10.4236/apm.2016.611061 unfortun... The original online version of this article (Issa Allassane Kaboye, Bazanfaré Mahaman (2016) Manifolds with Bakry-Emery Ricci Curvature bounded below 6, 754-764. http://dx.doi.org/10.4236/apm.2016.611061 unfortunately contains a mistake. The author wishes to correct the errors. 展开更多
关键词 Erratum
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Exploring Zika's dynamics:A scoping review journey from epidemic to equations through mathematical modelling
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作者 Jhoana P.Romero-Leiton Elda K.E.Laison +4 位作者 Rowin Alfaro E.Jane Parmley Julien Arino Kamal R.Acharya Bouchra Nasri 《Infectious Disease Modelling》 2025年第2期536-558,共23页
Zika virus(ZIKV)infection,along with the concurrent circulation of other arboviruses,presents a great public health challenge,reminding the utilization of mathematical modelling as a crucial tool for explaining its in... Zika virus(ZIKV)infection,along with the concurrent circulation of other arboviruses,presents a great public health challenge,reminding the utilization of mathematical modelling as a crucial tool for explaining its intricate dynamics and interactions with co-circulating pathogens.Through a scoping review,we aimed to discern current mathematical models investigating ZIKV dynamics,focusing on its interplay with other pathogens,and to identify underlying assumptions and deficiencies supporting attention,particularly regarding the epidemiological attributes characterizing Zika outbreaks.Following the PRISMA-Sc guidelines,a systematic search across PubMed,Web of Science,and MathSciNet provided 137 pertinent studies from an initial pool of 2446 papers,showing a diversity of modelling approaches,predominantly centered on vector-host compartmental models,with a notable concentration on the epidemiological landscapes of Colombia and Brazil during the 2015–2016 Zika epidemic.While modelling studies have been important in explaining Zika transmission dynamics and their intersections with diseases such as Dengue,Chikungunya,and COVID-19 so far,future Zika models should prioritize robust data integration and rigorous validation against diverse datasets to improve the accuracy and reliability of epidemic prediction.In addition,models could benefit from adaptable frameworks incorporating human behavior,environmental factors,and stochastic parameters,with an emphasis on open-access tools to foster transparency and research collaboration. 展开更多
关键词 Zika virus Mathematical modelling ARBOVIRUSES EPIDEMIOLOGY Public health
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Mathematical modeling of contact tracing and stability analysis to inform its impact on disease outbreaks;an application to COVID-19
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作者 Mohamed Ladib Aziz Ouhinou Abdul-Aziz Yakubu 《Infectious Disease Modelling》 CSCD 2024年第2期329-353,共25页
We develop a mathematical model to investigate the effect of contact tracing on containing epidemic outbreaks and slowing down the spread of transmissible diseases.We propose a discrete-time epidemic model structured ... We develop a mathematical model to investigate the effect of contact tracing on containing epidemic outbreaks and slowing down the spread of transmissible diseases.We propose a discrete-time epidemic model structured by disease-age which includes general features of contact tracing.The model is fitted to data reported for the early spread of COVID-19 in South Korea,Brazil,and Venezuela.The calibrated values for the contact tracing parameters reflect the order pattern observed in its performance intensity within the three countries.Using the fitted values,we estimate the effective reproduction number R_(e)and investigate its responses to varied control scenarios of contact tracing.Alongside the positivity of solutions,and a stability analysis of the disease-free equilibrium are provided. 展开更多
关键词 Mathematical modeling Infectious diseases Discrete systems Disease-age structured populations Contact tracing Effective reproduction number COVID-19
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SOME MATHEMATICAL MODELS AND MATHEMATICAL ANALYSIS ABOUT RAYLEIGH-TAYLOR INSTABILITY
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作者 Boling Guo Binqiang Xie 《Annals of Applied Mathematics》 2019年第1期1-46,共46页
In this paper we will review some mathematical models and mathematical analysis about Rayleigh-Taylor instability.
关键词 MATHEMATICAL MODELS MATHEMATICAL analysis RAYLEIGH-TAYLOR INSTABILITY
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A mathematical model for unsteady mixed flows in closed water pipes
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作者 BOURDARIAS Christian ERSOY Mehmet GERBI Stéphane 《Science China Mathematics》 SCIE 2012年第2期221-244,共24页
We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes.In the case of free surface incompressible flows,the FS-model is formally obtained,using formal ... We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes.In the case of free surface incompressible flows,the FS-model is formally obtained,using formal asymptotic analysis,which is an extension to more classical shallow water models.In the same way,when the pipe is full,we propose the P-model,which describes the evolution of a compressible inviscid flow,close to gas dynamics equations in a nozzle.In order to cope with the transition between a free surface state and a pressured(i.e.,compressible) state,we propose a mixed model,the PFS-model,taking into account changes of section and slope variation. 展开更多
关键词 SHALLOW water equations UNSTEADY MIXED FLOWS free surface FLOWS pressurized FLOWS curvilinear transformation ASYMPTOTIC analysis
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THE APPLICATION OF RANDOM MATRICES IN MATHEMATICAL PHYSICS
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作者 Boling Guo Fangfang Li 《Annals of Applied Mathematics》 2017年第3期221-238,共18页
In this paper, we introduce the application of random matrices in mathe- matical physics including Riemann-Hilbert problem, nuclear physics, big data, image processing, compressed sensing and so on. We start with the ... In this paper, we introduce the application of random matrices in mathe- matical physics including Riemann-Hilbert problem, nuclear physics, big data, image processing, compressed sensing and so on. We start with the Riemann- Hilbert problem and state the relation between the probability distribution of nontrivial zeros and the eigenvalues of the random matrices. Through the random matrices theory, we derive the distribution of Neutron width and prob- ability density between energy levels. In addition, the application of random matrices in quantum chromo dynamics and two dimensional Einstein gravity equations is also present in this paper. 展开更多
关键词 random matrices Riemann Hypothesis Riemann-Hilbert prob-lem nuclear physics
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基于FACNNCN的高分遥感影像场景分类方法
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作者 张婧 杨宇浩 +2 位作者 曹峰 张超 李德玉 《数据采集与处理》 北大核心 2025年第6期1637-1649,共13页
高分遥感影像场景分类旨在对复杂的地表场景影像进行精确认知,对于高分遥感影像的理解和信息提取具有重要的意义。本文提出了一种高分遥感影像场景方法,该方法基于特征聚合卷积神经网络(Feature aggregated convolution neural network,... 高分遥感影像场景分类旨在对复杂的地表场景影像进行精确认知,对于高分遥感影像的理解和信息提取具有重要的意义。本文提出了一种高分遥感影像场景方法,该方法基于特征聚合卷积神经网络(Feature aggregated convolution neural network,FACNN)和向量胶囊网络(Capsule network,CapsNet),即FACNNCN网络。通过增加聚合特征提升场景分类中影像特征的区分力和鲁棒性,并基于向量胶囊网络表征场景影像中地物与场景的空间关系,有效弥补了当前基于卷积神经网络的高分遥感影像场景分类方法中普遍存在的场景影像特征提取不充分、地物空间特征欠考虑的不足。本文提出的方法在2个公共高分遥感影像场景分类数据集(UC Merced Land⁃Use和NWPU⁃RESISC45)上进行了测试,实验结果表明该方法的分类精度优于相关的对比方法。 展开更多
关键词 高分遥感影像 场景分类 特征聚合 卷积神经网络 胶囊网络
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多模态视觉语言表征学习模型及其对抗样本攻防技术综述
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作者 曾诚 葛云洁 +1 位作者 赵令辰 王骞 《计算机研究与发展》 北大核心 2025年第9期2208-2232,共25页
随着计算机视觉、自然语言处理与深度学习技术的快速发展,多模态视觉语言表征学习模型在图像描述、文本生成图像、视觉问答等任务中展现出了卓越的性能,已成为当前学术界与工业界共同关注的研究热点.然而,这类模型的多模态特性和复杂性... 随着计算机视觉、自然语言处理与深度学习技术的快速发展,多模态视觉语言表征学习模型在图像描述、文本生成图像、视觉问答等任务中展现出了卓越的性能,已成为当前学术界与工业界共同关注的研究热点.然而,这类模型的多模态特性和复杂性为攻击者提供了更加多样的攻击途径,攻击者可以通过对抗样本引导模型输出错误的、有害的或虚假的内容,使该类模型面临的安全威胁日益严峻.系统地梳理了多模态视觉语言模型的研究现状,同时,对近年来出现的针对该类模型的对抗样本攻击方法及其防御策略进行了分类总结,详细归纳了相关研究的基本原理、实施方法与研究结论.在此基础上,对多模态视觉语言表征学习的安全研究现状与未来方向进行了探讨,并展望了视觉语言表征学习技术在未来结合可解释性技术的应用前景. 展开更多
关键词 表征学习 视觉语言学习 对抗性攻击 对抗性防御 网络空间安全
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面向单目可见光环境的自适应双手重建网络
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作者 廖国琼 黄龙杰 +2 位作者 李清新 辜勇 李海波 《图学学报》 北大核心 2025年第4期837-846,共10页
准确重建双手手部网格对于自然的人机交互体验来说是一个至关重要的过程,但由于双手的遮挡、户外收集双手交互数据集的复杂性和复杂的光照环境干扰等因素导致双手手部重建任务仍极具挑战性。目前已有的工作大多是在环境干扰比较小的实... 准确重建双手手部网格对于自然的人机交互体验来说是一个至关重要的过程,但由于双手的遮挡、户外收集双手交互数据集的复杂性和复杂的光照环境干扰等因素导致双手手部重建任务仍极具挑战性。目前已有的工作大多是在环境干扰比较小的实验室等场景下取得的的良好效果,而在复杂的光照场景中的重建效果仍不佳。为了解决上述问题,提出一种面向单目可见光环境的自适应手部重建网络。通过引入单手检测框和使用2D复杂光照场景数据集进行弱监督等策略使得模型得以对复杂光照场景产生泛化性;设计的双手特征交互器得以有效建立左右手特征的远距离依赖关系,缓解了单手检测框缺乏双手交互信息的问题;针对如何有效融合交互特征与单手特征的问题,设计了自适应融合的策略,增强了模型的鲁棒性。实验结果表明,在包含多个复杂光照场景的HIC数据集中取得了最佳的效果。 展开更多
关键词 复杂光照场景 手部网格 双手交互 弱监督 特征融合
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