期刊文献+
共找到2,191篇文章
< 1 2 110 >
每页显示 20 50 100
一类Stancu型的Szász-Mirakjan-Durrmeyer算子的逼近性质研究
1
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
下载PDF
光的衍射的理论分析及Mathematica仿真模拟 被引量:6
2
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
下载PDF
循环噪声作用下周期调制双稳系统的驻留时间分布函数
3
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
下载PDF
基于改进YOLOv8算法的实时细粒度植物病害检测
4
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
下载PDF
分数阶Logistic模型的差分解与环境容纳量反演
5
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
下载PDF
A Procedure for Trisecting an Acute Angle (Method 2)
6
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
下载PDF
Adjustments for Kurtosis and Continuity on the Prentice Test
7
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
下载PDF
基于天牛须搜索算法的UWSN聚簇路由协议
8
作者 常欣睿 《科学技术创新》 2024年第10期74-77,共4页
本研究针对水下无线传感器网络(UWSN)中存在的诸如高端到端延迟、链路质量不佳、路由空洞问题以及节点的移动性等挑战,提出了一种新的路由协议-基于天牛须搜索算法的聚簇路由协议(Beetle Antennae Search Algorithm clustered routing p... 本研究针对水下无线传感器网络(UWSN)中存在的诸如高端到端延迟、链路质量不佳、路由空洞问题以及节点的移动性等挑战,提出了一种新的路由协议-基于天牛须搜索算法的聚簇路由协议(Beetle Antennae Search Algorithm clustered routing protocol,BASC)。首先初始化一定数量的簇头节点,再根据适应度函数进行簇头择优,进而形成最佳的簇头节点集进行数据传输。采用ns-2软件对BASC协议与DUCS协议进行对比仿真实验测试,结果表明:BASC协议总能耗比DUCS协议降低26%,数据传递率提高约17%。实验证明,BASC协议有效提高了网络可靠性、减少了网络时延与能耗。提高了UWSN的整体通信性能。 展开更多
关键词 水下传感器网络 路由算法 能耗 多路径路由
下载PDF
Fermat and Pythagoras Divisors for a New Explicit Proof of Fermat’s Theorem:a4 + b4 = c4. Part I
9
作者 Prosper Kouadio Kimou François Emmanuel Tanoé Kouassi Vincent Kouakou 《Advances in Pure Mathematics》 2024年第4期303-319,共17页
In this paper we prove in a new way, the well known result, that Fermat’s equation a<sup>4</sup> + b<sup>4</sup> = c<sup>4</sup>, is not solvable in ℕ , when abc≠0 . To show this ... In this paper we prove in a new way, the well known result, that Fermat’s equation a<sup>4</sup> + b<sup>4</sup> = c<sup>4</sup>, is not solvable in ℕ , when abc≠0 . To show this result, it suffices to prove that: ( F 0 ): a 1 4 + ( 2 s b 1 ) 4 = c 1 4 , is not solvable in ℕ , (where a 1 , b 1 , c 1 ∈2ℕ+1 , pairwise primes, with necessarly 2≤s∈ℕ ). The key idea of our proof is to show that if (F<sub>0</sub>) holds, then there exist α 2 , β 2 , γ 2 ∈2ℕ+1 , such that ( F 1 ): α 2 4 + ( 2 s−1 β 2 ) 4 = γ 2 4 , holds too. From where, one conclude that it is not possible, because if we choose the quantity 2 ≤ s, as minimal in value among all the solutions of ( F 0 ) , then ( α 2 ,2 s−1 β 2 , γ 2 ) is also a solution of Fermat’s type, but with 2≤s−1<s , witch is absurd. To reach such a result, we suppose first that (F<sub>0</sub>) is solvable in ( a 1 ,2 s b 1 , c 1 ) , s ≥ 2 like above;afterwards, proceeding with “Pythagorician divisors”, we creat the notions of “Fermat’s b-absolute divisors”: ( d b , d ′ b ) which it uses hereafter. Then to conclude our proof, we establish the following main theorem: there is an equivalence between (i) and (ii): (i) (F<sub>0</sub>): a 1 4 + ( 2 s b 1 ) 4 = c 1 4 , is solvable in ℕ , with 2≤s∈ℕ , ( a 1 , b 1 , c 1 )∈ ( 2ℕ+1 ) 3 , coprime in pairs. (ii) ∃( a 1 , b 1 , c 1 )∈ ( 2ℕ+1 ) 3 , coprime in pairs, for wich: ∃( b ′ 2 , b 2 , b ″ 2 )∈ ( 2ℕ+1 ) 3 coprime in pairs, and 2≤s∈ℕ , checking b 1 = b ′ 2 b 2 b ″ 2 , and such that for notations: S=s−λ( s−1 ) , with λ∈{ 0,1 } defined by c 1 − a 1 2 ≡λ( mod2 ) , d b =gcd( 2 s b 1 , c 1 − a 1 )= 2 S b 2 and d ′ b = 2 s−S b ′ 2 = 2 s B 2 d b , where ( 2 s B 2 ) 2 =gcd( b 1 2 , c 1 2 − a 1 2 ) , the following system is checked: { c 1 − a 1 = d b 4 2 2+λ = 2 2−λ ( 2 S−1 b 2 ) 4 c 1 + a 1 = 2 1+λ d ′ b 4 = 2 1+λ ( 2 s−S b ′ 2 ) 4 c 1 2 + a 1 2 =2 b ″ 2 4;and this system implies: ( b 1−λ,2 4 ) 2 + ( 2 4s−3 b λ,2 4 ) 2 = ( b ″ 2 2 ) 2;where: ( b 1−λ,2 , b λ,2 , b ″ 2 )={ ( b ′ 2 , b 2 , b ″ 2 )  if λ=0 ( b 2 , b ′ 2 , b ″ 2 )  if λ=1;From where, it is quite easy to conclude, following the method explained above, and which thus closes, part I, of this article. . 展开更多
关键词 Factorisation in Greatest Common Divisor Pythagoras Equation Pythagorician Triplets Fermat's Equations Pythagorician Divisors Fermat's Divisors Diophantine Equations of Degree 2 4-Integral Closure of in
下载PDF
The Relation between Mental Workload and Face Temperature in Flight Simulation
10
作者 Amin Bonyad Hamdi Ben Abdessalem Claude Frasson 《Journal of Behavioral and Brain Science》 2024年第2期64-92,共29页
In this research, we study the relationship between mental workload and facial temperature of aircraft participants during a simulated takeoff flight. We conducted experiments to comprehend the correlation between wor... In this research, we study the relationship between mental workload and facial temperature of aircraft participants during a simulated takeoff flight. We conducted experiments to comprehend the correlation between work and facial temperature within the flight simulator. The experiment involved a group of 10 participants who played the role of pilots in a simulated A-320 flight. Six different flying scenarios were designed to simulate normal and emergency situations on airplane takeoff that would occur in different levels of mental workload for the participants. The measurements were workload assessment, face temperatures, and heart rate monitoring. Throughout the experiments, we collected a total of 120 instances of takeoffs, together with over 10 hours of time-series data including heart rate, workload, and face thermal images and temperatures. Comparative analysis of EEG data and thermal image types, revealed intriguing findings. The results indicate a notable inverse relationship between workload and facial muscle temperatures, as well as facial landmark points. The results of this study contribute to a deeper understanding of the physiological effects of workload, as well as practical implications for aviation safety and performance. 展开更多
关键词 Mental Workload EEG Thermal Images Flight Simulation AVIATION Face Temperature
下载PDF
Fuzzy Henstock-Kurzweil Triple Integral on a Type 1 Quasi-Fuzzy Parallelepipedal Domain
11
作者 Kumwimba Seya Didier Kasongo Ntambwe Dany +2 位作者 Panga Lutanda Grégoire Mayuke Katshongo Jean Paul Lunda Ngoy Jean Pierre 《Journal of Applied Mathematics and Physics》 2024年第3期897-911,共15页
In this article, we propose by using the Hausdorff distance Simpson’s rule for the triple integral of a fuzzy-valued function and the error bound of this method, one of the variables of which is fuzzy. In addition, t... In this article, we propose by using the Hausdorff distance Simpson’s rule for the triple integral of a fuzzy-valued function and the error bound of this method, one of the variables of which is fuzzy. In addition, thin δ-fine partitions are introduced. The integration domain is a quasi-fuzzy parallelipiped. A numerical example is presented in order to show the application and the significance of the method. 展开更多
关键词 Fuzzy-Valued Function Hausdorff Distance Quasi-Fuzzy Parallelipiped Henstock Integral
下载PDF
The Dual of the Two-Variable Exponent Amalgam Spaces (Lq(),lp())(Ω)
12
作者 Sambourou Massinanke Sékou Coulibaly Mamadou Traore 《Journal of Applied Mathematics and Physics》 2024年第2期383-431,共49页
Wiener amalgam spaces are a class of function spaces where the function’s local and global behavior can be easily distinguished. These spaces are ex-tensively used in Harmonic analysis that originated in the work of ... Wiener amalgam spaces are a class of function spaces where the function’s local and global behavior can be easily distinguished. These spaces are ex-tensively used in Harmonic analysis that originated in the work of Wiener. In this paper: we first introduce a two-variable exponent amalgam space (L<sup>q</sup><sup>()</sup>,l<sup>p</sup><sup>()</sup>)(Ω). Secondly, we investigate some basic properties of these spaces, and finally, we study their dual. 展开更多
关键词 Amalgam Spaces Variable Exponent Lebesgue Spaces Dual of a Vector Space
下载PDF
New Fusion Approach of Spatial and Channel Attention for Semantic Segmentation of Very High Spatial Resolution Remote Sensing Images
13
作者 Armand Kodjo Atiampo Gokou Hervé Fabrice Diédié 《Open Journal of Applied Sciences》 2024年第2期288-319,共32页
The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requ... The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requires considering spatial local context and long-term dependencies. To address this problem, the proposed approach is inspired by the MAC-UNet network which is an extension of U-Net, densely connected combined with channel attention. The advantages of this solution are as follows: 4) The new model introduces a new attention called propagate attention to build an attention-based encoder. 2) The fusion of multi-scale information is achieved by a weighted linear combination of the attentions whose coefficients are learned during the training phase. 3) Introducing in the decoder, the Spatial-Channel-Global-Local block which is an attention layer that uniquely combines channel attention and spatial attention locally and globally. The performances of the model are evaluated on 2 datasets WHDLD and DLRSD and show results of mean intersection over union (mIoU) index in progress between 1.54% and 10.47% for DLRSD and between 1.04% and 4.37% for WHDLD compared with the most efficient algorithms with attention mechanisms like MAU-Net and transformers like TMNet. 展开更多
关键词 Spatial-Channel Attention Super-Token Segmentation Self-Attention Vision Transformer
下载PDF
GLOBAL BIFURCATION AND CHAOS IN A VAN DER POL-DUFFING-MATHIUE SYSTEM WITH A SINGLE-WELL POTENTIAL OSCILLATOR 被引量:1
14
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
下载PDF
Mathematical Model of the Spread of the Coronavirus Disease 2019 (COVID-19) in Burkina Faso
15
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
下载PDF
Applying a Mathematical Model to the Performance of a Female Monofin Swimmer 被引量:1
16
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
下载PDF
MathWorks推出与机器人操作系统(ROS)完整集成的Robotics System Toolbox
17
《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
下载PDF
SIEMENS AUTOMATION和MATHWORKS在仿真与基于模型的设计方面展开协作
18
《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
下载PDF
基于微积分理论的玉米收获机作业效率优化 被引量:1
19
作者 程凤林 崔红芳 《农机化研究》 北大核心 2023年第5期201-205,共5页
为提升玉米收获机的作业效率,提出以微积分控制理论为优化主导,针对其核心结构与作业控制展开应用性研究。以通用型玉米收获机的主要作业流程为依据,结合整机作业过程特点,搭建用于收获机各环节的微积分控制优化模型,针对机体的核心结... 为提升玉米收获机的作业效率,提出以微积分控制理论为优化主导,针对其核心结构与作业控制展开应用性研究。以通用型玉米收获机的主要作业流程为依据,结合整机作业过程特点,搭建用于收获机各环节的微积分控制优化模型,针对机体的核心结构及执行部件进行相适应性设计,给出微积分算法下的导向控制执行系统与干扰控制系统设计,并展开针对性的收获作业试验。试验结果表明:基于微积分理论的玉米收获机结构与控制设计,收获含杂率与籽粒破碎率明显降低,系统运行准确、平稳,整机的作业效率相对可提升9.26%,对于我国类似农用收获机械的持续创新有重要的参考价值。 展开更多
关键词 玉米收获机 作业效率 微积分控制 籽粒破损率 精准化
下载PDF
A mathematical perspective on the determination of coastal peopling nuclei
20
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
下载PDF
上一页 1 2 110 下一页 到第
使用帮助 返回顶部