期刊文献+
共找到10篇文章
< 1 >
每页显示 20 50 100
Fuzzy格上的KKM定理
1
作者 施恩伟 《模糊系统与数学》 CSCD 2000年第1期51-56,共6页
讨论定义在 Fuzzy格上的某类映射的性质 ,主要结果是定理 2 .1。近几年来 ,国内外许多专家、学者热心研究的 KKM定理 ,广义 KKM定理等许多结果 ,都是定理 2 .1的一些简单的推论。由此说明 ,Fuzzy格理论具有广泛的应用性。
关键词 FUZZY格 拓扑分子路 可缩元 KKM定理
下载PDF
香港房委会建议提高公屋居屋入息限额
2
《中外房地产导报》 1997年第6期43-43,共1页
香港房委会建议由4月1日起,调整申请公屋及居屋的入息限额,轮候公屋入息限额平均提高10.2%,而居屋白表入息限额亦提高15.38%,由现时的2.6万元增加至3万元。这个建议有利亦有弊,
关键词 公屋 房委会 公营房屋 香港 家庭 有效分配 资格申请 市民 可缩元 平均增幅
下载PDF
An SDN/NFV Based Framework for Management and Deployment of Service Based 5G Core Network 被引量:23
3
作者 Lu Ma Xiangming Wen +2 位作者 Luhan Wang Zhaoming Lu Raymond Knopp 《China Communications》 SCIE CSCD 2018年第10期86-98,共13页
The traffic explosion and the rising of diverse requirements lead to many challenges for traditional mobile network architecture on flexibility, scalability, and deployability. To meet new requirements in the 5 G era,... The traffic explosion and the rising of diverse requirements lead to many challenges for traditional mobile network architecture on flexibility, scalability, and deployability. To meet new requirements in the 5 G era, service based architecture is introduced into mobile networks. The monolithic network elements(e.g., MME, PGW, etc.) are split into smaller network functions to provide customized services. However, the management and deployment of network functions in service based 5 G core network are still big challenges. In this paper, we propose a novel management architecture for 5 G service based core network based on NFV and SDN. Combined with SDN, NFV and edge computing, the proposed framework can provide distributed and on-demand deployment of network functions, service guaranteed network slicing, flexible orchestration of network functions and optimal workload allocation. Simulations are conducted to show that the proposed framework and algorithm are effective in terms of reducing network operating cost. 展开更多
关键词 service based architecture 5G core network SDN NFV workload allocation
下载PDF
Research on relationship between leakage of incompressible fluid and pressure change in pipeline 被引量:2
4
作者 YANG Li ZENG Zhoumo +2 位作者 FENG Hao HE Yongfang GAO Chao 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第2期146-153,共8页
In practical engineering,only pressure sensors are allowed to install to detect leakage in most of oil transportation pipelines,while flowmeters are only installed at the toll ports.For incompressible fluid,the leakag... In practical engineering,only pressure sensors are allowed to install to detect leakage in most of oil transportation pipelines,while flowmeters are only installed at the toll ports.For incompressible fluid,the leakage rate and amount cannot be accurately calculated through critical pressure conditions.In this paper,a micro-element body of the pipeline was intercepted for calculation.The relationship between radial displacement and pressure of pipe wall was studied based on the stress-strain equation.Then,the strain response of pipeline volume with pipeline pressure was obtained.The change in volume expansion of pipeline was used to characterize leakage of incompressible fluid.Finally,the calculation model of leakage amount of incompressible fluid was obtained.To verify the above theory,the pipeline expansion model under pressure was established by COMSOL software for simulation.Both simulation results and deduction equations show that the volumetric change has a quadratic parabolic relationship with the change of pipeline pressure.However,the relationship between them can be approximately linear when the pressure change is not too large.In addition,the leakage of incompressible fluid under the pressure of 0 MPa-0.8 MPa was obtained by experiments.The experimental results verify the linear relationship between leakage of incompressible fluid and the change of pipeline pressure.The theoretical and experimental results provide a basis for the calculation of leakage of incompressible fluid in the pipeline. 展开更多
关键词 incompressible fluid volumetric strain finite element simulation pressure gradient LEAKAGE
下载PDF
Multigrid fictitious boundary method for incompressible viscous flows around moving airfoils
5
作者 WAN De-Cheng 《Journal of Marine Science and Application》 2007年第2期51-58,共8页
In this paper, an efficient multigrid fictitious boundary method (MFBM) coupled with the FEM solver package FEATFLOW was used for the detailed simulation of incompressible viscous flows around one or more moving NAC... In this paper, an efficient multigrid fictitious boundary method (MFBM) coupled with the FEM solver package FEATFLOW was used for the detailed simulation of incompressible viscous flows around one or more moving NACA0012 airfoils. The calculations were carded on a fixed multigrid finite element mesh on which fluid equations were satisfied everywhere, and the airfoils were allowed to move freely through the mesh. The MFBM was employed to treat interactions between the fluid and the airfoils The motion of the airfoils was modeled by Newton-Euler equations. Numerical results of experiments verify that this method provides an efficient way to simulate incompressible viscous flows around moving airfoils. 展开更多
关键词 AIRFOILS induced-motion fictitious boundary method FEM MULTIGRID
下载PDF
Trajectory Attractors for Binary Fluid Mixtures in 3D 被引量:3
6
作者 Ciprian G.GAL Maurizio GRASSELLI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2010年第5期655-678,共24页
Two different models for the evolution of incompressible binary fluid mixtures in a three-dimensional bounded domain are considered.They consist of the 3D incompressible Navier-Stokes equations,subject to time-depende... Two different models for the evolution of incompressible binary fluid mixtures in a three-dimensional bounded domain are considered.They consist of the 3D incompressible Navier-Stokes equations,subject to time-dependent external forces and coupled with either a convective Allen-Cahn or Cahn-Hilliard equation.Such systems can be viewed as generalizations of the Navier-Stokes equations to two-phase fluids.Using the trajectory approach,the authors prove the existence of the trajectory attractor for both systems. 展开更多
关键词 Navier-Stokes equations Allen-Cahn equations Cahn-Hilliard equations Two-phase fluid flows Longtime behavior Trajectory attractors
原文传递
A class of nonconforming quadrilateral finite elements for incompressible flow 被引量:1
7
作者 HUANG ZhongYi LI Ye 《Science China Mathematics》 SCIE 2013年第2期379-393,共15页
This paper focuses on the low-order nonconforming rectangular and quadrilateral finite elements approximation of incompressible flow.Beyond the previous research works,we propose a general strategy to construct the ba... This paper focuses on the low-order nonconforming rectangular and quadrilateral finite elements approximation of incompressible flow.Beyond the previous research works,we propose a general strategy to construct the basis functions.Under several specific constraints,the optimal error estimates are obtained,i.e.,the first order accuracy of the velocities in H1-norm and the pressure in L2-norm,as well as the second order accuracy of the velocities in L2-norm.Besides,we clarify the differences between rectangular and quadrilateral finite element approximation.In addition,we give several examples to verify the validity of our error estimates. 展开更多
关键词 incompressible flow finite element method nonconforming quadrilateral elements optimal error estimates
原文传递
On the use of the discontinuous Galerkin method for numerical simulation of two-dimensional compressible turbulence with shocks 被引量:5
8
作者 YU Jian YAN Chao JIANG ZhenHua 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第9期1758-1770,共13页
In this paper,the discontinuous Galerkin(DG)method combined with localized artificial diffusivity is investigated in the context of numerical simulation of broadband compressible turbulent flows with shocks for under-... In this paper,the discontinuous Galerkin(DG)method combined with localized artificial diffusivity is investigated in the context of numerical simulation of broadband compressible turbulent flows with shocks for under-resolved cases.Firstly,the spectral property of the DG method is analyzed using the approximate dispersion relation(ADR)method and compared with typical finite difference methods,which reveals quantitatively that significantly less grid points can be used with DG for comparable numerical error.Then several typical test cases relevant to problems of compressible turbulence are simulated,including one-dimensional shock/entropy wave interaction,two-dimensional decaying isotropic turbulence,and two-dimensional temporal mixing layers.Numerical results indicate that higher numerical accuracy can be achieved on the same number of degrees of freedom with DG than high order finite difference schemes.Furthermore,shocks are also well captured using the localized artificial diffusivity method.The results in this work can provide useful guidance for further applications of DG to direct and large eddy simulation of compressible turbulent flows. 展开更多
关键词 discontinuous Galerkin compressible turbulence shock capturing artificial diffusivity
原文传递
A semi-implicit three-step method based on SUPG finite element formulation for flow in lid driven cavities with different geometries 被引量:1
9
作者 Cheng HUAN Dai ZHOU Yan BAO 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2011年第1期33-45,共13页
A numerical algorithm using a bilinear or linear finite element and semi-implicit three-step method is presented for the analysis of incompressible viscous fluid problems. The streamline upwind/Petrov-Galerkin (SUPG) ... A numerical algorithm using a bilinear or linear finite element and semi-implicit three-step method is presented for the analysis of incompressible viscous fluid problems. The streamline upwind/Petrov-Galerkin (SUPG) stabilization scheme is used for the formulation of the Navier-Stokes equations. For the spatial discretization, the convection term is treated explicitly, while the viscous term is treated implicitly, and for the temporal discretization, a three-step method is employed. The present method is applied to simulate the lid driven cavity problems with different geometries at low and high Reynolds numbers. The results compared with other numerical experiments are found to be feasible and satisfactory. 展开更多
关键词 Semi-implicit three-step method Streamline upwind/Petrov-Galerkin (SUPG) finite element method (FEM) Unsteady incompressible flows Lid driven cavity problem
原文传递
Finite element analysis of micropipette aspiration considering finite size and compressibility of cells
10
作者 LI YongSheng CHEN WeiYi 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第11期2208-2215,共8页
Micropipette aspiration(MA) is widely applied in cell mechanics, however, at small deformations a common model corresponding to the MA is the half-space model wherein the finite cell size and cell compressibility are ... Micropipette aspiration(MA) is widely applied in cell mechanics, however, at small deformations a common model corresponding to the MA is the half-space model wherein the finite cell size and cell compressibility are neglected. This study extends the half-space model by accounting for the influence of cell geometry and compressibility(sphere model). Using a finite element analysis of cell aspiration into a micropipette, an elastic approximation formula of the aspirated length was derived for the sphere model. The approximation formula includes the geometry parameter of the sphere model(ζ = R/a, R is the radius of the cell, and a is the inner radius of the micropipette) and the Poisson's ratio v of the cell. The results indicate that the parameter and Poisson's ratio v markedly affect the aspirated length, particularly for small and v. When ζ→∞ and v→0.5,the approximation formula tends to the analytical solution for the half-space model. In the incompressible case(v = 0.5), within the general experimental range(ζ varying from 2 to 4), the difference between the analytical solution and the approximate one is significant, and is up to 29% of the approximation solution when ζ= 2. Additionally, parametere was introduced to evaluate the error of elastic moduli between the half-space model and sphere model. Based on the approximation formula, the ζ thresholds, beyond which e becomes larger than 10% and 20%, were derived. 展开更多
关键词 micropipette aspiration mechanical properties finite size COMPRESSIBILITY approximation formula
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部