期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
On the Triple Sums of Hecke Eigenvalues on Certain Polynomials
1
作者 HUA Guodong 《数学进展》 北大核心 2025年第6期1261-1277,共17页
Let f,g and h be three distinct primitive holomorphic cusp forms of even integral weights k_(1),k_(2)and k_(3)for the full modular groupΓ=SL(2,Z),and denote byλ_(f)(n),λ_(g)(n),λ_(h)(n)the corresponding normalized... Let f,g and h be three distinct primitive holomorphic cusp forms of even integral weights k_(1),k_(2)and k_(3)for the full modular groupΓ=SL(2,Z),and denote byλ_(f)(n),λ_(g)(n),λ_(h)(n)the corresponding normalized Fourier coefficients,respectively.In this paper,we investigate the correlations of triple sums associated to these Fourier coefficientsλ_(f)(n),λ_(g)(n),λ_(h)(n)over certain polynomials,and obtain some power-saving asymptotic estimates which beat the trivial bounds. 展开更多
关键词 Hecke eigenvalue triple correlation sum automorphic L-function asymptotic behavior
原文传递
中国的数学——几件数学新闻和对于中国数学的一些看法 被引量:4
2
作者 陈省身 《自然科学进展(国家重点实验室通讯)》 1997年第2期129-135,共7页
张存浩先生要我讲点数学。这么短的时间,而数学这么大,只好举几个要点谈谈。数学是什么?数学是根据某些假设、用逻辑的推理得到结论。因为用这么简单的方法,所以数学是一门坚固的科学。它得到的结论是很有效的。这样的结论自然对学问的... 张存浩先生要我讲点数学。这么短的时间,而数学这么大,只好举几个要点谈谈。数学是什么?数学是根据某些假设、用逻辑的推理得到结论。因为用这么简单的方法,所以数学是一门坚固的科学。它得到的结论是很有效的。这样的结论自然对学问的各方面都很有应用,不过有一点很奇怪的,就是这种应用的范围非常大。最初你用几个数或画几个图就得到一些结论,而由此引起的发展却常常令人难以想象。在这个发展过程中,我认为不仅在数学上最重要,而且在人类文化吏上也非常突出的就是Euclid的《几何原本》。这是第一本系统性的书, 展开更多
关键词 数学 中国 有限元 单群 四色问题 椭圆曲线
在线阅读 下载PDF
Analysis of Imperfect Acoustic Cloaking Resonances
3
作者 KIM Seungil 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第12期119-122,共4页
We study the resonance phenomenon arising from imperfect acoustic cloaking in 2D based on a small perturbation of the transformation acoustics.It is shown that the resonant frequencies of imperfect cloaking appearing ... We study the resonance phenomenon arising from imperfect acoustic cloaking in 2D based on a small perturbation of the transformation acoustics.It is shown that the resonant frequencies of imperfect cloaking appearing in the total scattering cross section converge to Dirichlet eigenvalues of the concealed region as a perturbation parameter approaches zero.This theory enables us to predict the location of the resonant frequencies of imperfect cloaking and to identify the corresponding resonance modes. 展开更多
关键词 PERTURBATION imperfect RESONANT
原文传递
A New Approach to Vague Soft Bi-Topological Spaces
4
作者 Arif Mehmood Saleem Abdullah Choonkil Park 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第4期411-428,共18页
Fuzzy soft topology considers only membership value.It has nothing to do with the non-membership value.So an extension was needed in this direction.Vague soft topology addresses bothmembership and non-membership value... Fuzzy soft topology considers only membership value.It has nothing to do with the non-membership value.So an extension was needed in this direction.Vague soft topology addresses bothmembership and non-membership values simultaneously.Sometimes vague soft topology(single structure)is unable to address some complex structures.So an extension to vague soft bi-topology(double structure)was needed in this direction.To make this situation more meaningful,a new concept of vague soft bi-topological space is introduced and its structural characteristics are attempted with a new definition.In this article,new concept of vague soft bi-topological space(VSBTS)is initiated and its structural behaviors are attempted.This approach is based on generalized vague soft open sets,known as vague softβopen sets.An ample of examples are given to understand the structures.For the non-validity of some results,counter examples are provided to pay the price.Pair-wise vague softβopen and pair-wise vague softβclose sets are alsoaddressedwith examples in(VSBTS).Vague soft separation axioms are initiatedin(VSBTS)concerning soft points of the space.Other separation axioms are also addressed relative to soft points of the space.Vague soft bi-topological properties are studied with the application of vague softβopen sets with respect to soft points of the spaces.The characterization of vague softβclose as well as vague softβopen sets,characteristics of Bolzano Weirstrass property,vague soft compactness and its marriage with sequences,interconnection between sequential compactness and countable compactness in(VSBTS)with respect to softβopen sets are addressed. 展开更多
关键词 Vague soft set vague soft point vague soft bi-topological space vague softβ-open set and vague softβ-separation axioms
在线阅读 下载PDF
Suppression of the Resonant Scattering in Imperfect Acoustic Cloaking with a Lossy Medium in R^3
5
作者 LI Meng-Lei KIM Seungil 《Chinese Physics Letters》 SCIE CAS CSCD 2014年第5期80-83,共4页
It has been realized that resonance frequencies of imperfect the transformation acoustics in R^2 are located near Dirichlet acoustic cloaking based on a small perturbation of eigenvalues of the cloaked region [Chin. P... It has been realized that resonance frequencies of imperfect the transformation acoustics in R^2 are located near Dirichlet acoustic cloaking based on a small perturbation of eigenvalues of the cloaked region [Chin. Phys. Lett. 26 (2009) 014301; 29 (2012) 124301]. In this work, we study the performance of the three-dimensional approximate cloaking system based on the transformation acoustics and show that the cloaking effect may be deteriorated at zeroth order Neumann eigenvalues of the concealed region. In particular, transmitted fields into the concealed region can be extremely resonated at frequencies corresponding to the zeroth-order Neumann eigenvalues while scattered fields are suppressed well for any frequency. To enhance the cloaking effect at resonance frequencies, we introduce a lossy medium inside the cloaked region and show that the new proposal can reduce the intensity of transmitted fields significantly due to the lossy medium. 展开更多
原文传递
Mathematical modeling and optimal control problems in brain tumor targeted drug delivery strategies
6
作者 Aziz Belmiloudi 《International Journal of Biomathematics》 2017年第4期235-296,共62页
In this paper, we present a mathematical model that describes tumor-normal cells inter- action dynamics focusing on role of drugs in treatment of brain tumors. The goal is to predict distribution and necessary quantit... In this paper, we present a mathematical model that describes tumor-normal cells inter- action dynamics focusing on role of drugs in treatment of brain tumors. The goal is to predict distribution and necessary quantity of drugs delivered in drug-therapy by using optimal control framework. The model describes interactions of tumor and normal cells using a system of reactions^diffusion equations involving the drug concentration, tumor cells and normal tissues. The control estimates simultaneously blood perfusion rate, reabsorption rate of drug and drug dosage administered, which affect the effects of brain tumor chemotherapy. First, we develop mathematical framework which mod- els the competition between tumor and normal cells under chemotherapy constraints. Then, existence, uniqueness and regularity of solution of state equations are proved as well as stability results. Afterwards, optimal control problems are formulated in order to minimize the drug delivery and tumor cell burden in different situations. We show existence and uniqueness of optimal solution, and we derive necessary conditions for optimality. Finally, to solve numerically optimal control and optimization problems, we propose and investigate an adjoint multiple-relaxation-time lattice Boltzmann method for a general nonlinear coupled anisotropic convection-diffusion system (which includes the developed model for brain tumor targeted drug delivery system). 展开更多
关键词 Optimal control coupled nonlinear reaztion-diffusion equations anisotropicbrain tumor growth diffusion tensor drug delivery chemotherapy real-time monitoringof distribution logistic growth pointwise controllers adjoint system population dyna-mics magnetic resonance imaging (MRI) convection-enhanced delivery (CED) adjointmultiple-relaxation-time lattice Boltzmann method multiscale Chapman-Enskog expan-sion optimization of therapies.
原文传递
A Variational Finite Element Model for Large-Eddy Simulations of Turbulent Flows 被引量:2
7
作者 Toma's Chac'on REBOLLO Roger LEWANDOWSKI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第5期667-682,共16页
The authors introduce a new Large Eddy Simulation model in a channel, based on the projection on finite element spaces as filtering operation in its variationM form, for a given triangulation (Th)h〉0. The eddy visc... The authors introduce a new Large Eddy Simulation model in a channel, based on the projection on finite element spaces as filtering operation in its variationM form, for a given triangulation (Th)h〉0. The eddy viscosity is expressed in terms of the friction velocity in the boundary layer due to the wall, and is of a standard sub grid-model form outside the boundary layer. The mixing length scale is locally equal to the grid size. The computational domain is the channel without the linear sub-layer of the boundary layer. The no-slip boundary condition (or BC for short) is replaced by a Navier (BC) at the computational wall. Considering the steady state case, the authors show that the variational finite element model they have introduced, has a solution (Vh,Ph)h〉O that converges to a solution of the steady state Navier-Stokes equation with Navier BC. 展开更多
关键词 Navier-Stokes equations Turbulence modeling Finite elements
原文传递
Plateau of α-function and c-minimal homoclinic orbits 被引量:1
8
作者 LI Xia CUI Xiaojun 《Science China Mathematics》 SCIE 2006年第7期922-931,共10页
We consider the construction of the plateau of theα-function in a hyperbolic and positive definite Lagrangian system,and link the boundries of theα-function's plateau with the distribution of c-minimal homoclini... We consider the construction of the plateau of theα-function in a hyperbolic and positive definite Lagrangian system,and link the boundries of theα-function's plateau with the distribution of c-minimal homoclinic orbits to Aubry sets. 展开更多
关键词 α-function β-function PLATEAU Aubry sets.
原文传递
Method of characteristics and first integrals for systems of quasi-linear partial differential equations of first order 被引量:1
9
作者 HAN ChongKyu PARK JongDo 《Science China Mathematics》 SCIE CSCD 2015年第8期1665-1676,共12页
Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of o... Given a set of independent vector fields on a smooth manifold, we discuss how to find a function whose zero-level set is invariant under the flows of the vector fields. As an application, we study the solvability of overdetermined partial differential equations: Given a system of quasi-linear PDEs of first order for one unknown function we find a necessary and sufficient condition for the existence of solutions in terms of the second jet of the coefficients. This generalizes to certain quasi-linear systems of first order for several unknown functions. 展开更多
关键词 overdetermined PDE system quasi-linear first order PDEs first integrals Pfai:fian systems Frobe-nius theorem
原文传递
Orthogonality and Quintic Functional Equations 被引量:1
10
作者 Choonkil PARK Jian Lian CUI Madjid Eshaghi GORDJI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2013年第7期1381-1390,共10页
Using the fixed point method, we prove the Hyers Ulam stability of an orthogonally quintic functional equation in Banach spaces and in non-Archimedean Banach spaces.
关键词 Hyers-Ulam stability orthogonally quintic functional equation fixed point orthogonalityspace non^Archimedean Banach space
原文传递
On Heat Kernel Estimates and Parabolic Harnack Inequality for Jump Processes on Metric Measure Spaces 被引量:1
11
作者 Zhen-Qing CHEN Panki KIM Takashi KUMAGAI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2009年第7期1067-1086,共20页
In this paper, we discuss necessary and sufficient conditions on jumping kernels for a class of jump-type Markov processes on metric measure spaces to have scale-invariant finite range parabolic Harnack inequality.
关键词 Dirichlet form jump process jumping kernel parabolic Harnack inequality heat kernel estimates
原文传递
On the global existence of weak solutions for the Cucker-Smale-Navier-Stokes system with shear thickening 被引量:1
12
作者 Seung-Yeal Ha Hwa Kil Kim +1 位作者 Jae-Myoung Kim Jinyeong Park 《Science China Mathematics》 SCIE CSCD 2018年第11期2033-2052,共20页
We study the large-time dynamics of Cucker-Smale(C-S)flocking particles interacting with nonNewtonian incompressible fluids.Dynamics of particles and fluids were modeled using the kinetic Cucker-Smale equation for par... We study the large-time dynamics of Cucker-Smale(C-S)flocking particles interacting with nonNewtonian incompressible fluids.Dynamics of particles and fluids were modeled using the kinetic Cucker-Smale equation for particles and non-Newtonian Navier-Stokes system for fluids,respectively and these two systems are coupled via the drag force,which is the main flocking(alignment)mechanism between particles and fluids.We present a global existence theory for weak solutions to the coupled Cucker-Smale-Navier-Stokes system with shear thickening.We also use a Lyapunov functional approach to show that sufficiently regular solutions approach flocking states exponentially fast in time. 展开更多
关键词 EMERGENCE FLOCKING Cucker-Smale model Navier-Stokes equation non-Newtonian fluid
原文传递
Pseudo-anti commuting Ricci tensor for real hypersurfaces in the complex hyperbolic quadric
13
作者 Young Jin Suh 《Science China Mathematics》 SCIE CSCD 2019年第4期679-698,共20页
We introduce a new notion of pseudo-anti commuting Ricci tensor for real hypersurfaces in the noncompact complex hyperbolic quadric Q^(m?)= SO_2~0,_m/SO_2SO_m and give a complete classi?cation of these hypersurfaces.
关键词 pseudo-anti COMMUTING Ricci tensor pseudo-Einstein A-isotropic A-principal COMPLEX conjugation COMPLEX HYPERBOLIC QUADRIC
原文传递
Weak and Strong Convergence for Fixed Points of Asymptotically Non-expansive Mappings
14
作者 Ze Qing LIU Shin Min KANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2004年第6期1009-1018,共10页
A few weak and strong convergence theorems of the modified three-step iterative sequence with errors and the modified Ishikawa iterative sequence with errors for asymptotically non-expansive mappings in any non-empty ... A few weak and strong convergence theorems of the modified three-step iterative sequence with errors and the modified Ishikawa iterative sequence with errors for asymptotically non-expansive mappings in any non-empty closed convex subsets of uniformly convex Banach spaces are established. The results presented in this paper substantially extend the results due to Chang (2001), Osilike and Aniagbosor (2000), Rhoades (1994) and Schu (1991). 展开更多
关键词 Asymptotically non-expansive mapping Fixed point Modified three-step iterative sequence with errors Modified Ishikawa iterative sequence with errors Uniformly convex Banach space Opial’s condition Weak convergence Strong convergence
原文传递
Symmetric Periodic Orbits and Uniruled Real Liouville Domains
15
作者 Urs FRAUENFELDER Otto van KOERT 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2016年第4期607-624,共18页
A real Liouville domain is a Liouville domain with an exact anti-symplectic involution. The authors call a real Liouville domain uniruled if there exists an invariant finite energy plane through every real point. Asym... A real Liouville domain is a Liouville domain with an exact anti-symplectic involution. The authors call a real Liouville domain uniruled if there exists an invariant finite energy plane through every real point. Asymptotically, an invariant finite energy plane converges to a symmetric periodic orbit. In this note, they work out a criterion which guarantees uniruledness for real Liouville domains. 展开更多
关键词 Symmetric periodic orbits Real symplectic manifolds Real uniruledness
原文传递
Low degree GW invariants of surfaces Ⅱ
16
作者 KIEM Young-Hoon LI Jun 《Science China Mathematics》 SCIE 2011年第8期1679-1706,共28页
We prove a conjectural formula of Maulik-Pandharipande on the degree one and two GW invariants of a surface with a smooth canonical divisor.We use the method of degeneration and the localized GW invariants introduced ... We prove a conjectural formula of Maulik-Pandharipande on the degree one and two GW invariants of a surface with a smooth canonical divisor.We use the method of degeneration and the localized GW invariants introduced by the authors. 展开更多
关键词 Gromov-Witten invariant cosection degeneration formula localized virtual cycle
原文传递
On extensions of matrix rings with skew Hochschild 2-cocycles
17
作者 Chan Yong HONG Nam Kyun KIM +1 位作者 Tai Keun KWAK Yang LEE 《Frontiers of Mathematics in China》 SCIE CSCD 2016年第4期869-900,共32页
We study structures of endomorphisms and introduce a skew Hochschild 2-cocycles related to Hochschild 2-cocycle. We moreover define skew Hochschild extensions equipped with skew Hochschild 2-cocycles, and then we exam... We study structures of endomorphisms and introduce a skew Hochschild 2-cocycles related to Hochschild 2-cocycle. We moreover define skew Hochschild extensions equipped with skew Hochschild 2-cocycles, and then we examine uniquely clean, Abelian, directly finite, symmetric, and reversible ring properties of skew Hochschild extensions and related ring systems. The results obtained here provide various kinds of examples of such rings. Especially, we give an answer negatively to the question of H. Lin and C. Xi for the corresponding Hochschild extensions of reversible (or semicommutative) rings. Finally, we establish three kinds of Hochschild extensions with Hochschild 2-cocycles and skew Hochschild 2-cocycles. 展开更多
关键词 Skew Hochschild extensions matrix rings skew triangular matrix rings (uniquely) clean rings symmetric rings
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部