期刊文献+
共找到1,018篇文章
< 1 2 51 >
每页显示 20 50 100
Examining the Use of Scott’s Formula and Link Expiration Time Metric for Vehicular Clustering
1
作者 Fady Samann Shavan Askar 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2421-2444,共24页
Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are sim... Implementing machine learning algorithms in the non-conducive environment of the vehicular network requires some adaptations due to the high computational complexity of these algorithms.K-clustering algorithms are simplistic,with fast performance and relative accuracy.However,their implementation depends on the initial selection of clusters number(K),the initial clusters’centers,and the clustering metric.This paper investigated using Scott’s histogram formula to estimate the K number and the Link Expiration Time(LET)as a clustering metric.Realistic traffic flows were considered for three maps,namely Highway,Traffic Light junction,and Roundabout junction,to study the effect of road layout on estimating the K number.A fast version of the PAM algorithm was used for clustering with a modification to reduce time complexity.The Affinity propagation algorithm sets the baseline for the estimated K number,and the Medoid Silhouette method is used to quantify the clustering.OMNET++,Veins,and SUMO were used to simulate the traffic,while the related algorithms were implemented in Python.The Scott’s formula estimation of the K number only matched the baseline when the road layout was simple.Moreover,the clustering algorithm required one iteration on average to converge when used with LET. 展开更多
关键词 CLUsTERING vehicular network scott’s formula FastPAM
下载PDF
Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
2
作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 Population balance equation CRYsTALLIZATION peridynamic differential operator eulers first-order explicit method
下载PDF
Reciprocity Relation between Alternative Gravity Formulas
3
作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2024年第4期1432-1440,共9页
We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists betw... We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists between both alternative gravity formulas with respect to the distances between mass centers. We conclude a one-to-one mapping of the two gravitational formulas. We don’t need Einstein’s construct of spacetime bending by matter. 展开更多
关键词 Gravity formulas Reciprocity Distance Relation NEWTON EINsTEIN Bhandari Higgs Field Dirac’s Large Number
下载PDF
Bushen Yizhi Formula regulates the IRE1αpathway to alleviate endoplasmic reticulum stress in an Alzheimer’s disease rat model
4
作者 XIRU XU YUAN FANG +5 位作者 BIAO ZHANG SHICHAO TENG XIANG WU JING ZHANG XIAOQUN GU MEIXIA MA 《BIOCELL》 SCIE 2023年第7期1595-1609,共15页
While the Bushen Yizhi Formula can treat Alzheimer’s disease(AD),the yet to be ascertained specific mechanism of action was explored in this work.Methods:Different concentrations of the Bushen Yizhi Formula and amylo... While the Bushen Yizhi Formula can treat Alzheimer’s disease(AD),the yet to be ascertained specific mechanism of action was explored in this work.Methods:Different concentrations of the Bushen Yizhi Formula and amyloid-beta peptide(Aβ)were used to treat rat pheochromocytoma cells(P12)and human neuroblastoma cells(SH-SY5Y).Cell morphological changes were observed to determine the in vitro cell damage.Cell Counting Kit(CCK)-8 assay and flow cytometry were employed to identify cell viability and apoptosis/cell cycle,respectively.Western blotting and immunohistochemistry were employed to measure the expressions of endoplasmic reticulum stress(ERS)-related proteins(GRP78 and CHOP),p-IRE1α,IRE1α,ASK1,p-JNK,JNK,Bax,Bcl-2,XBP-1,and Bim.Fura 2-acetoxymethyl ester(Fura-2/AM)was used to determine the intracellular calcium(Ca^(2+))concentration.Also,an AD model was constructed by injecting Aβinto the CA1 area of the hippocampus in Sprague Dawley rats.AD model rats were gavaged with different concentrations of Bushen Yizhi Formula for 14 consecutive days.The Morris water maze experiment was conducted to test the learning and memory of rats.Hematoxylin&Eosin(H&E)and Terminal-deoxynucleotidyl Transferase(TdT)-mediated dUTP Nick-End Labeling(TUNEL)staining were done to determine histopathological changes in the brain.Results:Bushen Yizhi Formula relieved the Aβ-induced effects including cell injury,decreased viability,increased apoptosis,G0/G1 phase cell cycle arrest,upregulation of GRP78,CHOP,p-IRE1α,p-JNK,Bax,XBP-1 and Bim,as well as down-regulation of Bcl-2.These results were also seen with IRE1αsilencing.While Aβsuppressed the learning and memory abilities of rats,the Bushen Yizhi Formula alleviated these effects of Aβ.Brain nerve cell injury induced by Aβcould also be treated with Bushen Yizhi Formula.Conclusion:Bushen Yizhi Formula could influence ERS through the IRE1αsignaling pathway to achieve its therapeutic effects on AD. 展开更多
关键词 Bushen Yizhi formula Alzheimer’s disease Endoplasmic reticulum stress IRE1α
下载PDF
与Stieltjes常数有关的两个交错级数之和
5
作者 魏金波 黄永忠 《大学数学》 2024年第4期51-58,共8页
对于与Stieltjes常数有关的两个交错级数,分别用一个无穷积分的特性和Euler-Maclaurin求和公式,得到其级数和的明确表达式.
关键词 stieltjes常数 euler-MACLAURIN求和公式 euler 级数的和
下载PDF
数论函数方程(φ_(2)(n))^(2)=S(SL(n^(k)))的正整数解
6
作者 李欣欣 高丽 《延安大学学报(自然科学版)》 2024年第3期81-84,共4页
设n是正整数,利用初等数论的方法和广义Euler函数φ_(2)(n)、Smarandache函数S(n)、Smarandache LCM函数SL(n)这3个函数的基本性质,讨论当k=2,5时数论函数方程(φ_(2)(n))^(2)=S(SL(n^(k)))的可解性,并给出了这2个方程相应的所有正整数... 设n是正整数,利用初等数论的方法和广义Euler函数φ_(2)(n)、Smarandache函数S(n)、Smarandache LCM函数SL(n)这3个函数的基本性质,讨论当k=2,5时数论函数方程(φ_(2)(n))^(2)=S(SL(n^(k)))的可解性,并给出了这2个方程相应的所有正整数解。研究结果丰富了数论函数方程的研究内容。 展开更多
关键词 广义euler函数φ_(2)(n) smarandache函数s(n) smarandache LCM函数sL(n) 正整数解
下载PDF
数论函数方程kφ(n)=11φ_(2)(n)+S(SL(n^(37)))的正整数解
7
作者 薛媛媛 贺艳峰 +1 位作者 李勰 韩帆 《延安大学学报(自然科学版)》 2024年第3期76-80,共5页
利用Euler函数φ(n)、广义Euler函数φ_(2)(n)、Smarandache LCM函数SL(n)和Smarandache函数S(n)的性质,并结合初等数论的方法,讨论了数论函数方程kφ(n)=11φ_(2)(n)+S(SL(n^(37)))的可解性,证明了该方程只有k=1,6,7,15,31,46,51时有... 利用Euler函数φ(n)、广义Euler函数φ_(2)(n)、Smarandache LCM函数SL(n)和Smarandache函数S(n)的性质,并结合初等数论的方法,讨论了数论函数方程kφ(n)=11φ_(2)(n)+S(SL(n^(37)))的可解性,证明了该方程只有k=1,6,7,15,31,46,51时有正整数解,并给出了它的所有正整数解。研究结果丰富了数论函数方程可解性的内容。 展开更多
关键词 广义euler函数φ_(2)(n) smarandache LCM函数sL(n) smarandache函数s(n) 正整数解
下载PDF
Euler Loading Formula of LargeDeflection and the Quick Solution for Large Deflection Equation of Beam and Column
8
作者 黄平 王培荣 樊卫勇 《International Journal of Mining Science and Technology》 SCIE EI 1997年第1期83-86,共4页
This paper develops Euler ’loadlng formula of large deflection to be easy to measure in-situ and puts forward the differeuce quick iterative solution ror large deflection of beam and column, whick can solve the uon-l... This paper develops Euler ’loadlng formula of large deflection to be easy to measure in-situ and puts forward the differeuce quick iterative solution ror large deflection of beam and column, whick can solve the uon-linear equation like a kind of θ"+K(s)f(θ) =0. 展开更多
关键词 large DEFLECTION euler LOADING formula non-linear EQUATION interative sOLUTION
下载PDF
The Bivariate Normal Integral via Owen’s T Function as a Modified Euler’s Arctangent Series
9
作者 Janez Komelj 《American Journal of Computational Mathematics》 2023年第4期476-504,共29页
The Owen’s T function is presented in four new ways, one of them as a series similar to the Euler’s arctangent series divided by 2&#960, which is its majorant series. All possibilities enable numerically stable ... The Owen’s T function is presented in four new ways, one of them as a series similar to the Euler’s arctangent series divided by 2&#960, which is its majorant series. All possibilities enable numerically stable and fast convergent computation of the bivariate normal integral with simple recursion. When tested  computation on a random sample of one million parameter triplets with uniformly distributed components and using double precision arithmetic, the maximum absolute error was 3.45 × 10<sup>-</sup><sup>16</sup>. In additional testing, focusing on cases with correlation coefficients close to one in absolute value, when the computation may be very sensitive to small rounding errors, the accuracy was retained. In rare potentially critical cases, a simple adjustment to the computation procedure was performed—one potentially critical computation was replaced with two equivalent non-critical ones. All new series are suitable for vector and high-precision computation, assuming they are supplemented with appropriate efficient and accurate computation of the arctangent and standard normal cumulative distribution functions. They are implemented by the R package Phi2rho, available on CRAN. Its functions allow vector arguments and are ready to work with the Rmpfr package, which enables the use of arbitrary precision instead of double precision numbers. A special test with up to 1024-bit precision computation is also presented. 展开更多
关键词 Owen’s T Function Bivariate Normal Integral eulers Arctangent series RECURsION R Package Phi2rho
下载PDF
Fractional sum and fractional difference on non-uniform lattices and analogue of Euler and Cauchy Beta formulas
10
作者 CHENG Jin-fa 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2021年第3期420-442,共23页
As is well known,the definitions of fractional sum and fractional difference of f(z)on non-uniform lattices x(z)=c1z^(2)+c2z+c3 or x(z)=c1q^(z)+c2q^(-z)+c3 are more difficult and complicated.In this article,for the fi... As is well known,the definitions of fractional sum and fractional difference of f(z)on non-uniform lattices x(z)=c1z^(2)+c2z+c3 or x(z)=c1q^(z)+c2q^(-z)+c3 are more difficult and complicated.In this article,for the first time we propose the definitions of the fractional sum and fractional difference on non-uniform lattices by two different ways.The analogue of Euler’s Beta formula,Cauchy’Beta formula on non-uniform lattices are established,and some fundamental theorems of fractional calculas,the solution of the generalized Abel equation on non-uniform lattices are obtained etc. 展开更多
关键词 difference equation of hypergeometric type non-uniform lattice fractional sum fractional difference special functions eulers Beta formula Cauchy’Beta formula
下载PDF
On the Weyl’s Lemma for Triharmonic Functions
11
作者 ZHENG Run-jie ZENG Jia-min FANG Yi 《Chinese Quarterly Journal of Mathematics》 2024年第3期288-294,共7页
In this paper,by choosing some appropriate test functions,we prove the Weyl’s lemma for triharmonic functions based on the new type of mean value formulas.
关键词 Weyl’s lemma Harmonic functions Triharmonic functions Test functions Mean value formulas
下载PDF
基于Euler/N-S方程的跨音速非线性静气动弹性问题研究 被引量:2
12
作者 郭承鹏 董军 +1 位作者 杨庆华 李俊甫 《航空计算技术》 2006年第6期40-44,共5页
在C-H网格的基础上,采用Jam eson的中心差分有限体积法求解Eu ler/N-S方程,采用结构影响系数法计算结构的弹性变形,用三角元面积加权法和常体积转换法(CVT)实现流固耦合。
关键词 有限体积法 euler/N—s方程 三角元面积加权法 柔度影响系数法 常体积转换法 流固耦合
下载PDF
New Color-Difference Formula Based on CIECAM97s 被引量:1
13
作者 宦晖 李为 赵达尊 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期149-152,共4页
To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new f... To deduce a new color difference formula based on CIE 1997 Color Appearance Model(CIECAM97s), a color space J a 1 b 1 is first constructed with color appearance descriptors J,a,b in CIECAM97s. The new formula is then deduced in the space and named CDF CIECAM97s. The factors for lightness, chroma and hue correction in the formula are derived by linear regression according to BFD? CP data sets. It is found by statistical analysis that CDF CIECAM97s is in closer accordance with the visual assessments when compared with CMC(1∶1), CIE94 and CIE L *a *b * color difference formulae. Based on color appearance model, the new color difference formula can be used to predict color difference perception in a varity of different viewing conditions. 展开更多
关键词 CIECAM97s color difference formulae color space
下载PDF
基于Ackermann's formula的类反斜线回滞系统滑模控制 被引量:1
14
作者 张达科 胡跃明 郭华芳 《机械工程学报》 EI CAS CSCD 北大核心 2005年第1期11-15,共5页
回滞现象广泛地存在于许多机械控制领域。由于回滞特性具有不可微性,从而使得对回滞系统的控制变得困难和复杂,同时由于回滞可能引起系统的振荡,甚至造成系统的不稳定,因此有必要对回滞系统的有效控制进行研究。考虑到回滞系统建模仍然... 回滞现象广泛地存在于许多机械控制领域。由于回滞特性具有不可微性,从而使得对回滞系统的控制变得困难和复杂,同时由于回滞可能引起系统的振荡,甚至造成系统的不稳定,因此有必要对回滞系统的有效控制进行研究。考虑到回滞系统建模仍然是个研究的领域,针对类反斜线回滞系统进行研究。把类反斜线回滞模型分解为确定的线性部分和已知上界的不确定非线性部分,利用Ackermann's formula给出了类反斜线回滞系统的滑模控制律。仿真表明此滑模控制律是有效的,同时此滑模控制保证了整个系统的稳定性。 展开更多
关键词 类反斜线回滞 滑模控制 Ackermann’s formula
下载PDF
任意曲线坐标系Euler方程S2流面的计算方法 被引量:1
15
作者 李得英 宋彦萍 +2 位作者 陈浮 郑振江 陈焕龙 《西安交通大学学报》 EI CAS CSCD 北大核心 2015年第7期42-48,共7页
为提高S2流面计算方法对涡轮复杂几何的适应性和计算能力,详细推导了任意正交曲线坐标系下应用于流道中心S2流面计算的Euler方程,提出了任意曲线坐标系Euler方程S2流面的计算方法,发展了适用于三阶精度总变差减小的差分格式的数学模型,... 为提高S2流面计算方法对涡轮复杂几何的适应性和计算能力,详细推导了任意正交曲线坐标系下应用于流道中心S2流面计算的Euler方程,提出了任意曲线坐标系Euler方程S2流面的计算方法,发展了适用于三阶精度总变差减小的差分格式的数学模型,结合了隐格式时间推进、Riemann问题求解等技术。在应用于带弧形凸起的流道及某直叶栅气动参数计算,并对某三级低压涡轮进行性能预测的结果表明:所提方法对激波具有较高的捕捉精度,能够较准确地获得叶栅气动参数分布,且与实验结果吻合良好;对于多级涡轮总性能参数和气动参数分布均有较高的计算精度,是一种可为涡轮设计提供快速、可靠的计算方法。 展开更多
关键词 s2流面计算方法 euler方程 任意正交曲线坐标系 总变差减小的差分格式 低压涡轮
下载PDF
Stieltjes常数的弱有界及其衍生Euler常数的数学表示
16
作者 向日光 《哈尔滨理工大学学报》 CAS 北大核心 2010年第3期73-76,共4页
为了探讨Euler常数γ的数学表示式,通过对Stieltjes常数γk=nl→im∞S(Nk)=∑Nn=1lnknn-1k+1lnk+1(N+1)(k=0,1,2,…)的一个弱有界进行了进一步的优化估计,然后从该估计出发,把Euler常数γ的一个数学表达式γ=limx→0+{∑∞n=11n1+x-1x}... 为了探讨Euler常数γ的数学表示式,通过对Stieltjes常数γk=nl→im∞S(Nk)=∑Nn=1lnknn-1k+1lnk+1(N+1)(k=0,1,2,…)的一个弱有界进行了进一步的优化估计,然后从该估计出发,把Euler常数γ的一个数学表达式γ=limx→0+{∑∞n=11n1+x-1x}的右边函数展成关于x的幂级数,并对其一致收敛性进行了详细地讨论.最后通过构造一个函数g(x)∑∞n=1(-1)n-1n1+x,(∞<1,x∈R)而得到Euler常数γ的一个新的数学表达式. 展开更多
关键词 stieltjes常数 euler常数 Ζ函数 sTIRLING公式
下载PDF
(p,q)型Minkowski空间的双曲Euler公式与反向Schwarz不等式
17
作者 李武明 许宁 《通化师范学院学报》 2010年第4期9-10,23,共3页
由Clifford代数Clp,q的生成空间Rp,q表述(p,q)型Minkowski空间,讨论(p,q)型Minkowski空间的性质.给出(p,q)型Minkowski空间Rn的双曲Euler公式;得到反向Schwarz不等式在Rn+中成立的一个充分必要条件及相关推论.
关键词 CLIFFORD代数 MINKOWsKI空间 双曲euler公式 反向schwarz不等式
下载PDF
S4B-2 Bushen-Yizhi Formula Inhibits the NLRP3/NFκB Mediated Neuroinflammation and Improves the Motor Dysfunction in a Mouse Model of Parkinson’s Disease
18
作者 王奇 《神经药理学报》 2018年第4期71-72,共2页
Objective:Parkinson’s disease(PD)is the second largest neurodegenerative disease following Alzheimer’s disease(AD),which associated with aging.There are many similarities in pathology and pathogenesis,even in the TC... Objective:Parkinson’s disease(PD)is the second largest neurodegenerative disease following Alzheimer’s disease(AD),which associated with aging.There are many similarities in pathology and pathogenesis,even in the TCM theory understanding,so we can learn from each other in the process of drug discovery.The clinical results showed that Bushen-Yizhi formula(BSYZ)could effectively improve the neurological function score of senile dementia patients and had a better anti-dementia effect.Further pharmacological studies showed that BSYZ had neuroprotective effects,such as anti-inflammatory,anti-oxidation,anti-apoptosis and neurotrophic effects.In this study,the therapeutic effect of BSYZ on PD was evaluated in vivo and in vivo,and its molecular mechanism was discussed in order to expand the scope of application of BSYZ and to provide strategies for drug discovery of related neurodegenerative diseases.Methods:C57 BL/6 mice were injected intraperitoneally with MPTP to construct a PD mouse model.BSYZ(1.46,2.92,5.84 mg·kg-1)was administered for two weeks,and the positive control group was given a NSAID,piroxicam(12.5 mg·kg-1).After 1 week of pretreatment,MPTP was used to construct a PD mouse model.The mice were subjected to Rotation test on days 1,3 and 5,6th day.and the movement coordination and exercise ability of the drug on PD mice were observed on theThe number of TH-positive cells,Iba1 and CD68-labeled microglial cells in SNpc region were observed by immunofluorescence to observe the proliferation and activation of microglial cells and GFAP-labeled astrocytes.Western blotting was used to detect the nuclear transfer of NLRP3,Caspase-1,ASC,pro-IL-1β,IL-1βand NF-κB in the midbrain.Results:1.BSYZ could significantly improve the expression of MPTP model mice in the experiment of fatigue and Y-maze,increase the number of neurons in SNpc region and the positive expression of TH protein.2.BSYZ significantly inhibited the number of Iba1/CD68-positive microglial cells in MPTP-model mice and decreased the number of GFAP-positive astrocytes.3.BSYZ significantly inhibited the expression of NLRP3-associated protein in BV2 microglial cells induced by LPS+ATP and inhibited the nuclear transfer of NF-κB.Conclusion:BSYZ can effectively relieve the motor dysfunction of PD model mice,improve the damage of dopaminergic neurons,inhibit the proliferation and activation of microglial cells and astrocytes,and have good anti-MPTPinduced neuroinflammation and neuroinflammation mediated by nuclear transfer of NF-κB.The results show that BSYZ has a good prospect of anti-Parkinson’s disease and provides valuable drug discovery strategies for the related neurodegenerative diseases. 展开更多
关键词 Parkinson’s disease Drug Discovery Bushen-Yizhi formula neuroinfl ammation
下载PDF
改进Euler公式在电池SOC估计中的应用 被引量:3
19
作者 赵小巍 张国煜 +2 位作者 蔡亦山 羌嘉曦 杨林 《电源技术》 CAS CSCD 北大核心 2014年第2期295-297,322,共4页
扩展卡尔曼滤波算法在估计电池荷电状态(SOC)时,往往利用显性Euler公式来描述电池模型的状态方程。显性Euler公式是一种单步计算方法,计算精度相对较低。因此,采用改进Euler公式代替显性Euler公式,并应用到卡尔曼滤波算法中。仿真结果表... 扩展卡尔曼滤波算法在估计电池荷电状态(SOC)时,往往利用显性Euler公式来描述电池模型的状态方程。显性Euler公式是一种单步计算方法,计算精度相对较低。因此,采用改进Euler公式代替显性Euler公式,并应用到卡尔曼滤波算法中。仿真结果表明,改进Euler公式能够提高电池模型的计算精度,从而大大提高SOC预测精度。 展开更多
关键词 扩展卡尔曼滤波 荷电状态 显性euler公式 改进euler公式
下载PDF
关于Euler函数的Makowski猜想
20
作者 乐茂华 《广西师范学院学报(自然科学版)》 2007年第4期34-35,共2页
对于正整数n,设φ(n)是n的Euler函数.该文证明了:如果φ(n+3)=φ(n)+2,则n=2pr或2pr-3,其中p是适合p≡3(mod 4)的素数,r是正整数.
关键词 euler函数 函数方程 必要条件
下载PDF
上一页 1 2 51 下一页 到第
使用帮助 返回顶部