期刊文献+
共找到971篇文章
< 1 2 49 >
每页显示 20 50 100
ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO LINEAR MATRIX MOMENT FUNCTION ALS:THEORY AND APPLICATIONS 被引量:5
1
作者 L.Jódar E.Defez E.Ponsoda 《Analysis in Theory and Applications》 1996年第1期96-115,共20页
In this paper orthogonal matrix polynomials with respect to a right matrix moment functional an introduced. Basic results, important examples and applications to the approximation of matrix integrals are studied. Erro... In this paper orthogonal matrix polynomials with respect to a right matrix moment functional an introduced. Basic results, important examples and applications to the approximation of matrix integrals are studied. Error bounds for the proposed matrix quadrature rules are given. 展开更多
关键词 ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO LINEAR MATRIX moment function ALS 艺人 APPI
在线阅读 下载PDF
ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO A CONJUGATE BILINEAR MATRIX MOMENT FUNCTIONAL: BASIC THEORY 被引量:1
2
作者 Lucas Jodar and Emilio Defez (Polytechnical University of Valencia, Spain) 《Analysis in Theory and Applications》 1997年第1期66-79,共14页
In this paper basic results for a theory of orthogonal matrix polynomials with respect to a conjugate bilinear matrix moment functional are proposed. Properties of orthogonal matrix polynomial sequences including a th... In this paper basic results for a theory of orthogonal matrix polynomials with respect to a conjugate bilinear matrix moment functional are proposed. Properties of orthogonal matrix polynomial sequences including a three term matrix relationship are given. Positive definite conjugate bilinear matrix moment functionals are introduced and a characterization of positive definiteness in terms of a block Haenkel moment matrix is established. For each positive definite conjugate bilinear matrix moment functional an associated matrix inner product is defined. 展开更多
关键词 ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO A CONJUGATE BILINEAR MATRIX moment functionAL
在线阅读 下载PDF
Basis Sets Dependency in Constructing Spectroscopy-Accuracy Ab Initio Global Electric Dipole Moment Functions
3
作者 Yu Zhai Hui Li 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第1期52-57,I0062,共7页
Recently,more attention have been paid on the construction of dipole moment functions(DMF)using theoretical methods.However,the computational methods to construct DMFs are not validated as much as those for potential ... Recently,more attention have been paid on the construction of dipole moment functions(DMF)using theoretical methods.However,the computational methods to construct DMFs are not validated as much as those for potential energy surfaces do.In this letter,using Ar…He as an example,we tested how spectroscopyaccuracy DMFs can be constructed using ab initio methods.We especially focused on the basis set dependency in this scenario,i.e.,the convergence of DMF with the sizes of basis sets,basis set superposition error,and mid-bond functions.We also tested the explicitly correlated method,which converges with smaller basis sets than the conventional methods do.This work can serve as a pictorial sample of all these computational technologies behaving in the context of constructing DMFs. 展开更多
关键词 Dipole moment function Ab initio computation High-accuracy computation Basis set
在线阅读 下载PDF
A Class of Strong Limit Theorems and Moment Generating Function Method 被引量:1
4
作者 Wen Hart LI Gao Rong LI Nan Bin CAO 《Journal of Mathematical Research with Applications》 CSCD 2012年第1期76-82,共7页
In virtue of the notion of likelihood ratio and moment generating function, the limit properties of the sequences of absolutely continuous random variables are studied, and a class of strong limit theorems represented... In virtue of the notion of likelihood ratio and moment generating function, the limit properties of the sequences of absolutely continuous random variables are studied, and a class of strong limit theorems represented by inequalities with random bounds are obtained. 展开更多
关键词 likelihood ratio strong limit theorem moment generating function.
原文传递
On Moment Generating Function of Generalized Order Statistics from Erlang-Truncated Exponential Distribution
5
作者 Anamika Kulshrestha R. U. Khan Devendra Kumar 《Open Journal of Statistics》 2012年第5期557-564,共8页
In this paper explicit expressions and some recurrence relations are derived for marginal and joint moment generating functions of generalized order statistics from Erlang-truncated exponential distribution. The resul... In this paper explicit expressions and some recurrence relations are derived for marginal and joint moment generating functions of generalized order statistics from Erlang-truncated exponential distribution. The results for k-th record values and order statistics are deduced from the relations derived. Further, a characterizing result of this distribution on using the conditional expectation of function of generalized order statistics is discussed. 展开更多
关键词 Generalized Order STATISTICS Order STATISTICS Record Values Erlang-Truncated Exponential Distribution MARGINAL and Joint moment Generating function RECURRENCE Relations and Characterization
在线阅读 下载PDF
线性矩法在分布未知条件下的随机结构抗震可靠度分析
6
作者 吴罗成 张龙文 曾梦澜 《振动工程学报》 北大核心 2025年第1期180-190,共11页
在工程结构领域,由于数据不足,结构参数的分布通常未知,这成为结构可靠性分析中常见而复杂的挑战。在结构参数分布未知的情况下,本文提出了随机结构抗震可靠度分析的线性矩法。构造了仅由两个基本随机变量描述的随机动力系统:(1)基于结... 在工程结构领域,由于数据不足,结构参数的分布通常未知,这成为结构可靠性分析中常见而复杂的挑战。在结构参数分布未知的情况下,本文提出了随机结构抗震可靠度分析的线性矩法。构造了仅由两个基本随机变量描述的随机动力系统:(1)基于结构随机参数的前四阶线性矩,借助标准正态分布随机变量的随机函数表达,将结构参数的随机变量表示为仅有一个基本随机变量的一元三次多项式;(2)利用一个基本随机变量的随机函数‐谱表示模型描述非平稳地震动过程。在此基础上,根据数论方法确定两个基本随机变量的代表点集,进行时程分析并计算结构响应极值,进而计算确定界限下功能函数的样本及其线性矩;利用功能函数的前四阶线性矩求解三次多项式转换系数;并根据一元三次方程根的求解,建立基于线性矩的结构抗震可靠指标表达式。以结构参数分布未知的非线性单自由度为例说明了本文方法的应用,同时与Monte Carlo模拟结果对比,验证了本文方法的精确性。 展开更多
关键词 抗震可靠度 随机结构 线性矩 分布未知 随机函数-谱表示
在线阅读 下载PDF
电解铝车间通廊处轨道提升机组的设计与研究
7
作者 卢延峰 《有色设备》 2025年第1期63-68,共6页
本研究针对电解铝车间通廊处设置的轨道提升机组,在非集中大修时多功能天车在其上通行,而在集中大修时需将其提升一定的高度2种特定状态,进行了结构设计与优化分析。考虑到天车每侧端梁处的4个轮子轮距不等、载荷不对称的特点,本文运用... 本研究针对电解铝车间通廊处设置的轨道提升机组,在非集中大修时多功能天车在其上通行,而在集中大修时需将其提升一定的高度2种特定状态,进行了结构设计与优化分析。考虑到天车每侧端梁处的4个轮子轮距不等、载荷不对称的特点,本文运用函数解析法的最大值原理,确定了机组承受最大弯矩的位置及相应的计算公式,为设计中最危险截面的识别提供了理论依据。进一步结合挠曲梁受力分析与二阶非线性微分方程的极小值求解,推导出2个动滑轮的最佳安装位置,即当l/L=0.551时,在自重载荷作用下,采用相同材料和惯性矩的梁其变形量达到最小,有效减少了弯曲疲劳破坏。本研究提出的计算公式和设计方法对类似机构的设计计算具有参考价值。 展开更多
关键词 轨道提升机组 最大弯矩 函数解析法 挠曲梁受力分析 最佳安装位置
在线阅读 下载PDF
半封闭圆管冲击射流紊动特性PIV试验研究
8
作者 陈明 郭佳 +2 位作者 黄海津 杨岚彬 周绪生 《水利水运工程学报》 北大核心 2025年第4期128-142,共15页
冲击射流作为一种高效的质量、动量及能量传递技术,广泛应用于水利工程、热工设备及清洗系统等工程领域。在实际应用中,射流常受到结构空间的限制,形成半封闭冲击射流,其特征为喷嘴出口存在与冲击板平行的半封闭板,使射流流场结构更加复... 冲击射流作为一种高效的质量、动量及能量传递技术,广泛应用于水利工程、热工设备及清洗系统等工程领域。在实际应用中,射流常受到结构空间的限制,形成半封闭冲击射流,其特征为喷嘴出口存在与冲击板平行的半封闭板,使射流流场结构更加复杂,湍流特性显著变化。采用二维粒子图像测速技术,对不同冲击距条件下的半封闭圆管冲击射流流场进行了试验研究。通过获取射流中心面上的瞬时速度场,重点分析了紊动能、脉动速度概率密度、偏斜因子、平坦因子及两点相关函数的沿程演化规律。结果表明,随着冲击距的增大,自由射流剪切层内紊动能峰值及高紊动能区域均显著增大,而壁面射流区紊动能峰值呈现先增后减趋势;其中,壁面紊动能局部峰值沿径向呈指数衰减,其半值宽随径向线性增长,且扩展率与衰减指数对冲击距变化不敏感。脉动速度概率密度分析显示,射流中心线上轴向脉动速度分布由瘦高逐渐趋于扁平,壁面射流区的径向脉动速度分布则由扁平转向瘦高;进一步的偏斜因子与平坦因子分析表明,射流中心线上轴向脉动速度分布呈左偏态且陡峭特性,壁面射流区径向脉动速度分布则呈右偏态且陡峭特性,表明射流发展过程中存在非高斯性与间歇性特征。两点相关函数分析显示,积分长度尺度随射流发展沿程增大,表明湍流结构在沿程发展中不断合并、扩大。本研究深化了对半封闭冲击射流紊动特性的理解,为其在质量、动量及能量传递中的机理分析提供了试验支撑,并为相关工程应用中的结构优化与性能提升提供了理论依据。 展开更多
关键词 冲击射流 封闭板 紊动能 高阶速度矩 两点相关函数
在线阅读 下载PDF
基于缓冲函数和阻尼切换的构网型储能参数自适应调整方法 被引量:1
9
作者 崔杨 马搏余 +2 位作者 戴汉扬 马鑫 赵钰婷 《电力系统自动化》 北大核心 2025年第10期77-86,共10页
新型电力系统高比例新能源和高比例电力电子设备的发展趋势下,新能源并网采用构网型控制技术虽改善了系统因惯量和阻尼不足带来的稳定性问题,但同时也降低了系统动态调节性能。文中提出基于缓冲函数和稳态/暂态阻尼切换的构网型储能参... 新型电力系统高比例新能源和高比例电力电子设备的发展趋势下,新能源并网采用构网型控制技术虽改善了系统因惯量和阻尼不足带来的稳定性问题,但同时也降低了系统动态调节性能。文中提出基于缓冲函数和稳态/暂态阻尼切换的构网型储能参数自适应调整方法以改善系统动态调节性能。首先,在惯量调整中使用缓冲函数增加系统的调节平滑度。其次,在阻尼调整中引入稳态/暂态阻尼切换环节,减少频率下降时有功功率输出稳态误差。然后,通过模糊控制为惯量和阻尼引入修正量并对所提方法进行稳定性分析。最后,通过仿真验证了所提方法对提高系统小干扰稳定性和功率响应动态性能的有效性。 展开更多
关键词 新型电力系统 储能 构网型控制 转动惯量 阻尼系数 缓冲函数 自适应调整方法 小干扰稳定 模糊控制 动态性能
在线阅读 下载PDF
一种改进的分位数函数估计方法及其应用
10
作者 王璐 熊莉芳 +1 位作者 赵瑞勇 申林杰 《火箭推进》 北大核心 2025年第4期109-117,共9页
受到结构尺寸、材料及载荷等多种不确定因素的影响,液体火箭发动机结构的性能特征量也具有随机性,为了准确估计结构性能特征量的分位数函数,掌握结构性能的随机分布情况,衡量其可靠性水平,发展了一种改进的分位数函数估计方法。所提方... 受到结构尺寸、材料及载荷等多种不确定因素的影响,液体火箭发动机结构的性能特征量也具有随机性,为了准确估计结构性能特征量的分位数函数,掌握结构性能的随机分布情况,衡量其可靠性水平,发展了一种改进的分位数函数估计方法。所提方法对极大熵结合概率加权矩的分位数函数估计方法作出改进,将分数概率加权矩作为极大熵模型的约束条件,并利用Kullback-Lerble交叉熵方法将嵌套优化模型转换为单层优化模型,再通过分部积分和下标迭代方法进一步降低优化模型的求解参数个数,以提高其计算的稳健性,所提方法继承了概率加权矩结合极大熵方法需要的样本量较小、对异常样本不敏感的特点,并提高了原方法对分位数函数尾部区域的估计精度,最后通过数值算例和液体火箭发动机管路结构的工程案例充分验证了所提方法的优越性和应用价值。 展开更多
关键词 可靠性 分位数函数 概率加权矩 极大熵
在线阅读 下载PDF
Fisher准则函数在机械刀具切削磨损检测中的应用
11
作者 任慧 马金萍 《机械设计与制造》 北大核心 2025年第1期154-159,165,共7页
在高精度机床道具切削磨损无接触图像检测中,磨损区域边缘特征容易发生混淆,区分其像素边缘区域成为一个难点。Fisher判别函数可以用于特征提取,即通过选择最具有区分力的特征来改善分类性能。针对这一特点,提出基于Fisher准则函数的机... 在高精度机床道具切削磨损无接触图像检测中,磨损区域边缘特征容易发生混淆,区分其像素边缘区域成为一个难点。Fisher判别函数可以用于特征提取,即通过选择最具有区分力的特征来改善分类性能。针对这一特点,提出基于Fisher准则函数的机械刀具切削磨损检测方法。首先,对采集到的机械刀具切削磨损图像实施图像增强处理,利用实施修正线性拉伸操作解决光照不均匀问题,凸出刀具磨损区域的细节特征并提高图像质量;其次,利用基于Fisher准则函数的图像阈值分割方法,将刀体区域和其工作背景区域分割出来,使刀具磨损区域更加清晰,提高磨损区域的可识别性;最后,通过Roberts边缘检测确定刀具切削磨损边缘,并使用Zernike正交矩确定刀具切削磨损边缘的精确值以获取磨损区域,提取其磨损信息实现机械刀具切削磨损的检测。实验结果表明:所提方法具有较高图像处理能力以及磨损检测精度。 展开更多
关键词 图像增强 Fisher准则函数 图像阈值分割 Roberts边缘检测 Zernike正交矩 磨损检测
在线阅读 下载PDF
虚拟现实结合悬吊减重步态训练对截肢患者幻肢痛及下肢动力学表现的影响
12
作者 李琼英 李思敏 +3 位作者 曾敬茹 吴姁怿 雷中杰 杜春萍 《实用临床医药杂志》 2025年第9期65-69,74,共6页
目的 探讨虚拟现实结合悬吊减重步态训练对截肢患者幻肢痛及下肢动力学参数、步态稳定性、平衡功能、生活质量的影响。方法 前瞻性选取100例单侧下肢截肢患者作为研究对象,采用随机数字表法分为实验组和对照组,每组50例。实验组接受虚... 目的 探讨虚拟现实结合悬吊减重步态训练对截肢患者幻肢痛及下肢动力学参数、步态稳定性、平衡功能、生活质量的影响。方法 前瞻性选取100例单侧下肢截肢患者作为研究对象,采用随机数字表法分为实验组和对照组,每组50例。实验组接受虚拟现实结合悬吊减重步态训练,对照组接受常规康复训练。分别于干预前及干预后4、8、12周,评估2组患者的幻肢痛程度[视觉模拟评分法(VAS)、神经病理性疼痛4问卷(DN4)评分]、动力学参数[垂直方向地面反作用力(Fz)、前后方向地面反作用力(Fy)、关节力矩]、步态参数、静态平衡功能(Berg平衡量表评分)、动态平衡功能(稳定性时间、步态支撑时间占比)、生活质量[健康调查12条目简表(SF-12)评分]和日常生活能力[改良Barthel指数(MBI)评分]。结果 干预后4、8、12周,实验组患者VAS评分、DN4评分均低于干预前,且低于对照组,差异有统计学意义(P<0.05);干预后4、8、12周,实验组患者步速、步长、步频、支撑时间和Berg平衡量表评分、稳定性时间、步态支撑时间占比均较干预前增加,且较对照组增加,差异有统计学意义(P<0.05);实验组患者SF-12评分、MBI评分和Fz峰值、Fy峰值、膝关节屈曲力矩、踝关节外展力矩、支撑相比例均高于干预前,且高于对照组,差异有统计学意义(P<0.05)。结论 虚拟现实结合悬吊减重步态训练可显著缓解截肢患者幻肢痛,改善下肢动力学参数、步态稳定性和平衡功能,提升生活质量。 展开更多
关键词 虚拟现实 悬吊减重步态训练 截肢 幻肢痛 关节力矩 生活质量 动力学参数 平衡功能
暂未订购
基于线性矩的粤港澳大湾区极端降水区域频率分析
13
作者 杨芳 马志鹏 陈子燊 《中山大学学报(自然科学版)(中英文)》 北大核心 2025年第2期12-21,共10页
以1961—2023年粤港澳大湾区30个气象观测站年最大日降水数据为基础数据,应用区域线性矩法分析了大湾区各子区域极端降水频率的最优分布函数与重现设计水平。研究结果表明:1)使用KNN分类法和均质性判别准则将大湾区气象站点分成5个子区... 以1961—2023年粤港澳大湾区30个气象观测站年最大日降水数据为基础数据,应用区域线性矩法分析了大湾区各子区域极端降水频率的最优分布函数与重现设计水平。研究结果表明:1)使用KNN分类法和均质性判别准则将大湾区气象站点分成5个子区域,分别为位于西江中下游的Ⅰ区、位于中北部三角洲网河区的Ⅱ区、位于南部伶仃洋河口区两岸的Ⅲ区、位于西南部的Ⅳ区、位于东部的Ⅴ区;2)Ⅰ~Ⅴ子区域的最优分布线型依次为P-Ⅲ、GEV、GEV、P-Ⅲ、GEV。依据区域暴雨增长曲线的方法,分别推算了大湾区各站点的暴雨频率设计值。3)由优选的5个分区的区域最优分布函数计算的暴雨重现水平值可作为子区域内无站点处工程设计的参考依据。 展开更多
关键词 L-矩 区域极端降水 频率分析 KNN分类 区域最优分布函数
在线阅读 下载PDF
Regional moment-independent sensitivity analysis with its applications in engineering 被引量:8
14
作者 Changcong ZHOU Chenghu TANG +2 位作者 Fuchao LIU Wenxuan WANG Zhufeng YUE 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第3期1031-1042,共12页
Traditional Global Sensitivity Analysis(GSA) focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output ... Traditional Global Sensitivity Analysis(GSA) focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output is beyond the traditional GSA techniques.To fully address this issue,in this work,two regional moment-independent importance measures,Regional Importance Measure based on Probability Density Function(RIMPDF) and Regional Importance Measure based on Cumulative Distribution Function(RIMCDF),are introduced to find out the contributions of specific regions of an input to the whole output distribution.The two regional importance measures prove to be reasonable supplements of the traditional GSA techniques.The ideas of RIMPDF and RIMCDF are applied in two engineering examples to demonstrate that the regional moment-independent importance analysis can add more information concerning the contributions of model inputs. 展开更多
关键词 Cumulative distribution function moment-independent Probability density function Regional importance measure Sensitivity analysis Uncertainty
原文传递
IMPULSIVE DIFFERENTIAL EQUATIONS WITH GAMMA DISTRIBUTED MOMENTS OF IMPULSES AND P-MOMENT EXPONENTIAL STABILITY 被引量:1
15
作者 R.AGARWAL S.HRISTOVA +1 位作者 P.KOPANOV D.O'REGAN 《Acta Mathematica Scientia》 SCIE CSCD 2017年第4期985-997,共13页
Differential tigated. We study the properties of solutions sufficient conditions for equations with impulses at random moments are set up and invescase of Gamma distributed random moments of impulses. Several are stud... Differential tigated. We study the properties of solutions sufficient conditions for equations with impulses at random moments are set up and invescase of Gamma distributed random moments of impulses. Several are studied based on properties of Gammma distributions. Some p-moment exponential stability of the solutions are given. 展开更多
关键词 IMPULSES Gamma distributed moments of impulses p-moment exponentialstability Lyapunov functions
在线阅读 下载PDF
Ghost images reconstructed from fractional-order moments with thermal light 被引量:3
16
作者 De-Zhong Cao Qing-Chen Li +3 位作者 Xu-Cai Zhuang Cheng Ren Su-Heng Zhang Xin-Bing Song 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第12期238-243,共6页
We present the joint probability density function(PDF) between the bucket signals and reference signals in thermal light ghost imaging, by regarding these signals as stochastic variables. The joint PDF allows us to ex... We present the joint probability density function(PDF) between the bucket signals and reference signals in thermal light ghost imaging, by regarding these signals as stochastic variables. The joint PDF allows us to examine the fractional-order moments of the bucket and the reference signals, in which the correlation orders are fractional numbers,other than positive integers in previous studies. The experimental results show that various images can be reconstructed from fractional-order moments. Negative(positive) ghost images are obtained with negative(positive) orders of the bucket signals. The visibility and peak signal-to-noise ratios of the diverse ghost images depend greatly on the fractional orders. 展开更多
关键词 ghost imaging intensity correlation function fractional-order moments
原文传递
Elasticity Solution of Composite Material Wedge Loaded with a Concentrated Moment
17
作者 Gang Wang Purong Jia +2 位作者 Yongyong Suo Long Zhang Leilei Zeng 《Journal of Materials Science and Chemical Engineering》 2019年第8期77-85,共9页
The complex variable functions are used and analyzed for the solving the mechanic problem of composite plates. The stress boundary condition for composite material wedge is considered. By constructing new stress funct... The complex variable functions are used and analyzed for the solving the mechanic problem of composite plates. The stress boundary condition for composite material wedge is considered. By constructing new stress function, the mechanic analysis of the composite material wedge subjected to a concentrated moment is conducted. The stress boundary problem is studied and the basic governing equation is solved by using the complex function method. The formulae of the stress fields are derived for the wedge loaded with a concentrated moment. 展开更多
关键词 Composite Material Concentrated moment Complex function STRESS FIELDS
在线阅读 下载PDF
Transmuted Exponentiated Moment Pareto Distribution 被引量:1
18
作者 Muhammad Zeshan Arshad Muhammad Zafar Iqbal Munir Ahmad 《Open Journal of Statistics》 2018年第6期939-961,共23页
In this work, the authors proposed a four parameter potentiated lifetime model named as Transmuted Exponentiated Moment Pareto (TEMP) distribution and discussed numerous characteristic measures of proposed model. Para... In this work, the authors proposed a four parameter potentiated lifetime model named as Transmuted Exponentiated Moment Pareto (TEMP) distribution and discussed numerous characteristic measures of proposed model. Parameters are estimated by the method of maximum likelihood and performance of these estimates is also assessed by simulations study. Four suitable lifetime datasets are modeled by the TEMP distribution and the results support that the proposed model provides much better results as compared to its sub-models. 展开更多
关键词 Quadratic Rank TRANSMUTATION Map (QRTM) PARETO Distribution HAZARD function Fractional momentS INCOMPLETE momentS Rényi Entropy
在线阅读 下载PDF
Proportional integral derivative controller design using Legendre orthogonal functions
19
作者 Reza Moradi Mohammad Tabatabaei 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第10期2616-2629,共14页
The Legendre orthogonal functions are employed to design the family of PID controllers for a variety of plants. In the proposed method, the PID controller and the plant model are represented with their corresponding L... The Legendre orthogonal functions are employed to design the family of PID controllers for a variety of plants. In the proposed method, the PID controller and the plant model are represented with their corresponding Legendre series. Matching the first three terms of the Legendre series of the loop gain with the desired one gives the PID controller parameters. The closed loop system stability conditions in terms of the Legendre basis function pole(λ) for a wide range of systems including the first order, second order, double integrator, first order plus dead time, and first order unstable plants are obtained. For first order and double integrator plants, the closed loop system stability is preserved for all values of λ and for the other plants, an appropriate range in terms of λ is obtained. The optimum value of λ to attain a minimum integral square error performance index in the presence of the control signal constraints is achieved. The numerical simulations demonstrate the benefits of the Legendre based PID controller. 展开更多
关键词 PID controllers orthogonal functions legendre functions moment matching PI controller PD controller
在线阅读 下载PDF
A Wave Function for the Spin of the Early Universe Derived from the Wheeler-DeWitt Equation
20
作者 Juan Carlos Echaurren 《International Journal of Astronomy and Astrophysics》 2017年第2期62-68,共7页
The wave function for the spin the early universe is obtained through the adaption of the quantum formalism to one solution of the Wheeler-DeWitt’s equation [1], associated with the wave function of the universe. In ... The wave function for the spin the early universe is obtained through the adaption of the quantum formalism to one solution of the Wheeler-DeWitt’s equation [1], associated with the wave function of the universe. In addition, some observations performed by Stephen Hawking in relation to the vorticity of the universe [2] are used. This wave function for the spin could be used for indirectly to demonstrate the presence of dark matter in the universe. 展开更多
关键词 SPIN VORTICITY Rotation Angular moment Wave function of the UNIVERSE BLUESHIFT Great ATTRACTOR
在线阅读 下载PDF
上一页 1 2 49 下一页 到第
使用帮助 返回顶部