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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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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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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
关键词 正交各向异性材料 动力学问题 数学模型 自由场 酒吧 弹性薄板 旋转 位移
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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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A Procedure for Trisecting an Acute Angle (Method 2)
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作者 Lyndon O. Barton 《Advances in Pure Mathematics》 2024年第4期204-213,共10页
This paper presents an alternate graphical procedure (Method 2), to that presented in earlier publications entitled, “A Procedure for Trisecting an Acute Angle” and “A Key to Solving the Angle Trisection Problem”.... This paper presents an alternate graphical procedure (Method 2), to that presented in earlier publications entitled, “A Procedure for Trisecting an Acute Angle” and “A Key to Solving the Angle Trisection Problem”. The procedure, when applied to the 30˚ and 60˚ angles that have been “proven” to be nottrisectable and the 45˚ benchmark angle that is known to be trisectable, in each case produced a construction having an identical angular relationship with Archimedes’ Construction, as in Section 2 on THEORY of this paper, where the required trisection angle was found to be one-third of its respective angle (i.e. DE’MA = 1/3 DE’CG). For example, the trisection angle for the 30˚, 45˚ and 60˚ angles were 10.00000˚, 15.00000˚, and 20.00000˚, respectively, and Section 5 on PROOF in this paper. Therefore, based on this identical angular relationship and the numerical results (i.e. to five decimal places), which represent the highest degree of accuracy and precision attainable by The Geometer’s Sketch Pad software, one can only conclude that not only the geometric requirements for arriving at an exact trisection of the 30˚ and 60˚ angle (which have been “proven” to be not-trisectable) have been met, but also, the construction is valid for any arbitrary acute angle, despite theoretical proofs to the contrary by Wantzel, Dudley, and others. 展开更多
关键词 Archimedes’ Construction College Geometry College Mathematics Angle Trisection Famous Problems in Mathematics Mechanism Analysis Geometer’s Sketch Pad
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一类Stancu型的Szász-Mirakjan-Durrmeyer算子的逼近性质研究
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作者 连博勇 蔡清波 《高校应用数学学报(A辑)》 北大核心 2024年第2期211-217,共7页
该文介绍了一类Stancu型的Szász-Mirakjan-Durrmeyer算子,计算了该算子的一阶到四阶矩.然后用连续模和K-泛函等工具,讨论了该算子的逼近性质,还研究了算子对Lipschitz函数类的估计.最后建立了该算子的Voronvskaya型渐近展开式.所... 该文介绍了一类Stancu型的Szász-Mirakjan-Durrmeyer算子,计算了该算子的一阶到四阶矩.然后用连续模和K-泛函等工具,讨论了该算子的逼近性质,还研究了算子对Lipschitz函数类的估计.最后建立了该算子的Voronvskaya型渐近展开式.所得定理扩展了Aslan(2022)的结果. 展开更多
关键词 Szász-Mirakjan-Durrmeyer算子 K-泛函 连续模 Voronvskaya型渐近展开公式
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循环噪声作用下周期调制双稳系统的驻留时间分布函数
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作者 吴亚珍 孙中奎 《西北工业大学学报》 EI CAS CSCD 北大核心 2024年第1期165-172,共8页
提出了一种计算循环噪声作用下周期调制双稳系统驻留时间分布函数的理论方法。基于具有分段逃逸速率的两态模型理论,建立粒子逃逸的瞬时速率方程,推导得出驻留时间分布函数的递归表达式。基于此,分别计算信号振幅与循环噪声强度比值较... 提出了一种计算循环噪声作用下周期调制双稳系统驻留时间分布函数的理论方法。基于具有分段逃逸速率的两态模型理论,建立粒子逃逸的瞬时速率方程,推导得出驻留时间分布函数的递归表达式。基于此,分别计算信号振幅与循环噪声强度比值较大和较小2种不同情形下驻留时间分布函数的解析表达式。并且,从理论和数值模拟两方面分别阐明了循环噪声对驻留时间分布函数结构的影响。研究结果表明:驻留时间分布函数呈现指数衰减且在循环滞后时间处出现骤然下降趋势,且随着噪声强度和相关强度的增大驻留时间分布函数衰减速度变快,说明循环噪声能够加速粒子在势阱间的跃迁。此外,在周期信号的调制下,驻留时间分布函数在信号半周期的奇数倍处出现一系列峰值,这预示着系统发生了随机共振现象。 展开更多
关键词 循环噪声 周期调制双稳系统 驻留时间分布函数 随机共振
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基于改进YOLOv8算法的实时细粒度植物病害检测
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作者 薛霞 刘鹏 周文 《中国农机化学报》 北大核心 2024年第5期188-194,共7页
为解决现有识别方法在植物病害检测中遇到的密集分布、不规则形态、多尺度目标类别、纹理相似性等障碍,提出一种高性能的实时细粒度植物病害检测框架。首先,在YOLOv8主干网络和颈部设计两个新的残差块,增强特征提取和降低计算成本;其次... 为解决现有识别方法在植物病害检测中遇到的密集分布、不规则形态、多尺度目标类别、纹理相似性等障碍,提出一种高性能的实时细粒度植物病害检测框架。首先,在YOLOv8主干网络和颈部设计两个新的残差块,增强特征提取和降低计算成本;其次,引入DenseNet层,并使用Hard-Swish函数作为主要激活函数,以提高模型的准确性;最后,设计PANet网络,用于保留细粒度的局部信息和改善特征融合。在不同的复杂环境下,对番茄植株的四种不同病害进行检测。试验结果表明,所提改进模型在检测准确性和速度上均优于现有模型的检测模型。当检测速度为71.23 FPS时,所提改进模型精确度为92.58%,召回率为97.59%,F_(1)分数为93.64%。为精准农业自动化提供有效的技术手段。 展开更多
关键词 植物病害检测 改进YOLOv8 实时目标检测 深度神经网络 残差网络
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一类区间时滞忆阻神经网络的稳定性控制
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作者 赵一飞 曹梦亭 +2 位作者 褚佳奕 崔铠亭 章联生 《北京石油化工学院学报》 2024年第2期60-68,共9页
鉴于忆阻神经网络(memristive neural network,MNN)的数学模型是一种右端不连续的微分方程,经典的微分方程理论不再适用。借助微分包含理论和Filippov解的框架,将这一神经网络系统转化为通常的神经网络系统,并建立了时滞一次函数形式的... 鉴于忆阻神经网络(memristive neural network,MNN)的数学模型是一种右端不连续的微分方程,经典的微分方程理论不再适用。借助微分包含理论和Filippov解的框架,将这一神经网络系统转化为通常的神经网络系统,并建立了时滞一次函数形式的新型李雅普诺夫-克拉索夫斯基泛函(Lyapunov-Krasovskii functional,LKF),运用积分不等式和倒数凸组合不等式估计其导数,得到了该系统渐近稳定的充分条件并以线性矩阵不等式(linear matrix inequalities,LMIs)形式给出,便于用MATLAB软件验证。数值仿真结果表明,所得到结论正确且可实现。 展开更多
关键词 忆阻神经网络 全局渐进稳定 时变时滞 线性矩阵不等式
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分数阶Logistic模型的差分解与环境容纳量反演
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作者 李怡璇 贾现正 李功胜 《郑州大学学报(理学版)》 CAS 北大核心 2024年第2期87-94,共8页
对于具有空间依赖环境容纳量的分数阶Logistic非线性增长模型,通过变量替换建立有限差分格式,在环境容纳量适当大的条件下,利用谱估计方法证明差分格式的稳定性和收敛性。进而考虑一个利用内点观测数据重建环境容纳量的反问题,应用同伦... 对于具有空间依赖环境容纳量的分数阶Logistic非线性增长模型,通过变量替换建立有限差分格式,在环境容纳量适当大的条件下,利用谱估计方法证明差分格式的稳定性和收敛性。进而考虑一个利用内点观测数据重建环境容纳量的反问题,应用同伦正则化算法进行数据随机扰动下的数值反演,计算结果表明反演重建解随着扰动水平的减小逐步逼近真解。 展开更多
关键词 分数阶Logistic模型 环境容纳量 有限差分格式 稳定性与收敛性 反问题 数值反演
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A Key to Solving the Angle Trisection Problem
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作者 Lyndon O. Barton 《Advances in Pure Mathematics》 2023年第9期625-634,共10页
This paper describes the methodology (or approach) that was key to the solution of the angle trisection problem published earlier in article entitled, “A Procedure For Trisecting An Acute Angle.” It was an approach ... This paper describes the methodology (or approach) that was key to the solution of the angle trisection problem published earlier in article entitled, “A Procedure For Trisecting An Acute Angle.” It was an approach that required first, designing a working model of a trisector mechanism, second, studying the motion of key elements of the mechanism and third, applying the fundamental principles of kinematics to arrive at the desired results. In presenting these results, since there was no requirement to provide a detailed analysis of the final construction, this information was not included. However, now that the publication is out, it is considered appropriate as well as instructive to explain more fully the mechanism analysis of the trisector in graphical detail, as covered in Section 3 of this paper, that formed the basis of the long sought solution to the age-old Angle Trisection Problem. 展开更多
关键词 Archimedes’ Construction College Geometry College Mathematics Angle Trisection Trisector Famous Problems in Mathematics History of Mathematics Mechanism Analysis KINEMATICS Geometer’s Sketch Pad
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停车场车位识别算法研究
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作者 韩瑞东 杨攀 《运城学院学报》 2024年第3期31-36,共6页
随着城市化进程的加快和汽车保有量的迅猛增长,停车难问题日益严重,迫切需要高效的智能停车管理系统。基于此,提出了一种停车场车位识别算法,旨在自动检测和识别停车场中的空闲车位,提供实时车位信息,提高停车效率。首先,对停车场摄像... 随着城市化进程的加快和汽车保有量的迅猛增长,停车难问题日益严重,迫切需要高效的智能停车管理系统。基于此,提出了一种停车场车位识别算法,旨在自动检测和识别停车场中的空闲车位,提供实时车位信息,提高停车效率。首先,对停车场摄像头采集到的图像进行预处理,过滤掉多余背景信息;其次,利用霍夫变换检测停车区域的边界线,准确定位车位位置;最后,利用卷积神经网络对车位进行分类和识别(是否空闲),并进行可视化操作。实验结果表明,该算法具有较高的识别准确率,能够有效地识别空闲车位,具有一定的实用价值。 展开更多
关键词 图像预处理 霍夫变换 卷积神经网络 车位识别
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Adjustments for Kurtosis and Continuity on the Prentice Test
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作者 Lily Gebhart John Kolassa 《Advances in Pure Mathematics》 2024年第2期101-117,共17页
The test of Prentice [1] is a non-parametric statistical test for the two-way analysis of variance using ranks. The null distribution of this test typically is approximated using the Chi-square distribution. However, ... The test of Prentice [1] is a non-parametric statistical test for the two-way analysis of variance using ranks. The null distribution of this test typically is approximated using the Chi-square distribution. However, the exact null distribution deviates from the Chi-square approximation in certain cases commonly found in applications of the test, motivating adjustments to the distribution. This manuscript presents adjustments to this null distribution correcting for continuity, multivariate skewness, and multivariate kurtosis. The effects of alternative scoring methods as non-polynomial functions of rank sums are also presented as a broader application of the approximation. 展开更多
关键词 Friedman Test Prentice Test Edgeworth Approximation
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