检索结果-南通市图书馆

Acta Mathematica Scientia 2024年第1期44卷 189-194页

作者：东瑜昕林和子陆琳根 School of Mathematical sciences Fudan UniversityShanghai20043China School of Mathematics and statistics&Laboratory of analytical Mathematics and Applications(Ministry of Education)&FJKLMAA Fujian Normal UniversityFuzhou350108China

In this note,we prove a logarithmic Sobolev inequality which holds for compact submanifolds without a boundary in manifolds with asymptotically nonnegative sectional *** the Michale-Simon Sobolev inequality,this inequ... 详细信息

关键词： asymptotically nonnegative sectional curvature logarithmic Sobolev inequality ABP method

Tanaka Formula and Local Time for a Class of Interacting Branching Measure-valued Diffusions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第4期40卷 1059-1098页

作者： Donald A.DAWSON Jean VAILLANCOURT Hao WANG School of Mathematics and statistics Carleton UniversityOttawaCanada department of Decision sciences HECMontrealCanada department of Mathematics University of OregonEugeneUSA

We construct superprocesses with dependent spatial motion(SDSMs)in Euclidean spaces R^(d)with d≥1 and show that,even when they start at some unbounded initial positive Radon measure such as Lebesgue measure on R^(d),... 详细信息

关键词： Measure-valued diffusions stochastic partial differential equations superprocesses branching processes local time Tanaka formula

Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 197-216页

作者： C.G.PAVITHRA B.J.GIREESHA M.L.KEERTHI department of PG Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India department of Mathematics and statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTM) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTM) trihybrid nanofluid magnetic field

Completeness of Induced Cotorsion Pairs in Representation Categories of Rooted Quivers

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第10期40卷 2436-2452页

作者： Zhen Xing DI Li Ping LI Li LIANG Fei XU School of Mathematical sciences Huaqiao University LCSM (Ministry of Education) School of Mathematics and Statistics Hunan Normal University department of Mathematics Lanzhou Jiaotong University Gansu Provincial Research Center for Basic Disciplines of Mathematics and statistics department of Mathematics Shantou University

This paper focuses on a question raised by Holm and J?rgensen, who asked if the induced cotorsion pairs(Φ（X）, Φ（X）⊥) and(⊥Ψ（Y）, Ψ（Y）) in Rep（Q, A）—the category of all A-valued representations of a quiver Q—are complete whenever（X, Y） is a complete cotorsion pair in an abelian category A satisfying some mild conditions. We give an affirmative answer if the quiver Q is rooted. As an application, we show under certain mild conditions that if a subcategory L, which is not necessarily closed under direct summands, of A is special precovering（resp., preenveloping）, then Φ（L）(resp.,Ψ（L）) is special precovering（resp., preenveloping） in Rep（Q, A）.

关键词： 16G20 18G25 complete cotorsion pair Rooted quiver special precovering (preenveloping) subcategory

Healthy life expectancy with cardiovascular disease among Chinese rural population based on the prospective cohort study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2024年第8期21卷 799-806页

作者： Feng JIANG Xiao-Tian LIU Ze HU Wei LIAO Shuo-Yi LI Rui-Fang ZHU Zhen-Xing MAO Jian HOU Sohail Akhtar Fayaz Ahmad Tahir Mehmood Chong-Jian WANG department of Epidemiology and Biostatistics College of Public HealthZhengzhou UniversityZhengzhouChina department of Mathematics and statistics The University of HaripurHaripurPakistan School of Natural sciences National University of Sciences and TechnologyIslamabadPakistan

BACKGROUND Limited research has explored the impact of cardiovascular disease(CVD)on healthy life expectancy(HLE)especially in resource-limited *** study aimed to investigate the association between CVD and HLE in Chinese rural *** This study included 11,994 participants aged 45 years and older from the baseline and follow-up surveys of the Henan rural cohort *** status was measured via a Visual Analogue *** multistate Markov model was applied to estimate the association between CVD and transitions in health,unhealthiness and ***-specific total life expectancy,HLE and unhealthy life expectancy were calculated by the multistate life table *** During a mean follow-up time of 3.85(3.84–3.86)years,there were 588 deaths *** individuals with CVD,the risk of switching from health to unhealthiness status was increased by 71%[hazard ratio(HR)=1.71,95%CI:1.42–2.07],the chance of recovery was reduced by 30%(HR=0.70,95%CI:0.60–0.82).Men aged 45 years without CVD could gain an extra 7.08(4.15–10.01)years of HLE and lose 4.00(1.60–6.40)years of unhealthy life expectancy compared to their peers with CVD,*** corresponding estimates among women were 8.62(5.55–11.68)years and 5.82(2.59–9.04)years,*** This study indicated that CVD was significantly associated with poorer health status and lower HLE among Chinese rural *** is an important public health policy to adopt targeted measures to reduce the CVD burden and enhance the quality of life and HLE in resource-limited areas.

关键词： Healthy cardiovascular life

Optimal Model Average Prediction in Orthogonal Kriging Models

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第3期37卷 1080-1099页

作者： WANG Jun HE Jiabei LIANG Hua LI Xinmin School of Mathematics and statistics Qingdao UniversityQingdao 266071China department of statistics George Washington UniversityWashington DC 20052USA

The main objective of this paper is to consider model averaging methods for kriging *** paper proposes a Mallows model averaging procedure for the orthogonal kriging model and demonstrate the asymptotic optimality of the model averaging estimators in terms of mean square *** studies are conducted to evaluate the performance of the proposed method and compare it with the competitors to demonstrate its *** authors also analyse a real dataset for an illustration.

关键词： Asymptotic optimality Mallows criterion optimal model averaging orthogonal kriging model

On Polar Decomposition of Tensors with Einstein Product and a Novel Iterative Parametric Method

在线全文

学校读者我要写书评

暂无评论

Numerical Mathematics(Theory,Methods and Applications) 2024年第1期17卷 69-92页

作者： Raziyeh Erfanifar Masoud Hajarian Khosro Sayevand department of Applied Mathematics Faculty of Mathematical SciencesShahid Beheshti UniversityTehranIran Faculty of Mathematics and statistics Malayer UniversityMalayerIran

This study aims to investigate the polar decomposition of tensors with the Einstein product for theﬁrst *** polar decomposition of tensors can be computed using the singular value decomposition of the tensors with the Einstein *** the following,some iterative methods forﬁnding the polar decomposi-tion of matrices have been developed into iterative methods to compute the polar decomposition of ***,we propose a novel parametric iterative method toﬁnd the polar decomposition of *** the obtained conditions,we prove that the proposed parametric method has the order of convergence *** every iteration of the proposed method,only four Einstein products are required,while other iterative methods need to calculate multiple Einstein products and one tensor inversion in each ***,the new method is superior in terms of efﬁciency ***,the numerical comparisons performed among several well-known methods,show that the proposed method is remarkably efﬁcient and accurate.

关键词： Iterative methods Einstein product polar decomposition of a tensor polar factor order of convergence

A Novel Iterative Method to Find theMoore-Penrose Inverse of a Tensor with Einstein Product

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical Mathematics(Theory,Methods and Applications) 2024年第1期17卷 37-68页

In this study,based on an iterative method to solve nonlinear equations,a third-order convergent iterative method to compute the Moore-Penrose inverse of a tensor with the Einstein product is presented and *** compar-isons of the proposed method with other methods show that the average number of iterations,number of the Einstein products,and CPU time of our method are considerably less than other *** some applications,partial and fractional differential equations that lead to sparse matrices are considered as *** use the iterates obtained by the method as a preconditioner,based on tensor form to solve the multilinear system A∗N X=***,several practical numerical examples are also given to display the accuracy and efﬁciency of the new *** presented results show that the proposed method is very robust for obtaining the Moore-Penrose inverse of tensors.

关键词： Tensor iterative methods Moore-Penrose inverse Einstein product

A Local Macroscopic Conservative(LoMaC)Low Rank Tensor Method with the Discontinuous Galerkin Method for the Vlasov Dynamics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 550-575页

作者： Wei Guo Jannatul Ferdous Ema Jing-Mei Qiu department of Mathematics and statistics Texas Tech UniversityLubbockTX70409USA department of Mathematical sciences University of DelawareNewarkDE19716USA

In this paper,we propose a novel Local Macroscopic Conservative(LoMaC)low rank tensor method with discontinuous Galerkin(DG)discretization for the physical and phase spaces for simulating the Vlasov-Poisson(VP)*** LoMaC property refers to the exact local conservation of macroscopic mass,momentum,and energy at the discrete *** recently developed LoMaC low rank tensor algorithm(arXiv:2207.00518)simultaneously evolves the macroscopic conservation laws of mass,momentum,and energy using the kinetic flux vector splitting;then the LoMaC property is realized by projecting the low rank kinetic solution onto a subspace that shares the same macroscopic *** paper is a generalization of our previous work,but with DG discretization to take advantage of its compactness and flexibility in handling boundary conditions and its superior accuracy in the long *** algorithm is developed in a similar fashion as that for a finite difference scheme,by observing that the DG method can be viewed equivalently in a nodal *** the nodal DG method,assuming a tensorized computational grid,one will be able to(i)derive differentiation matrices for different nodal points based on a DG upwind discretization of transport terms,and(ii)define a weighted inner product space based on the nodal DG grid *** algorithm can be extended to the high dimensional problems by hierarchical Tucker(HT)decomposition of solution tensors and a corresponding conservative projection *** a similar spirit,the algorithm can be extended to DG methods on nodal points of an unstructured mesh,or to other types of discretization,e.g.,the spectral method in velocity *** numerical results are performed to showcase the efficacy of the method.

关键词： Hierarchical Tucker(HT)decomposition Conservative SVD Energy conservation Discontinuous Galerkin(DG)method

BIG HANKEL OPERATORS ON HARDY SPACES OF STRONGLY PSEUDOCONVEX DOMAINS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第3期44卷 789-809页

作者：陈伯勇江良英 School of Mathematical sciences Fudan UniversityShanghai200433China department of statistics and Mathematics Shanghai Lixin University of Accounting and FinanceShanghai201209China

In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f ) is bounded on H~p(Ω)(1

详细信息

In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f ) is bounded on H~p(Ω)(1

关键词： Hankel operator Hardy space Bergman space pseudoconvex domain