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排序方式: 共有297条查询结果,搜索用时 15 毫秒
1.
Liang-gen Hu 《应用数学学报(英文版)》2007,23(2):281-288
In this paper,we will establish several strong convergence theorems for the approximation ofcommon fixed points of r-strictly asymptotically pseudocontractive mappings in uniformly convex Banachspaces using the modiied implicit iteration sequence with errors,and prove the necessary and sufficient conditionsfor the convergence of the sequence.Our results generalize,extend and improve the recent work,in thistopic. 相似文献
2.
We propose general variational inclusion problems which are slightly different from corresponding problems considered in several recent papers in the literature and show that they are advantageous. Sufficient conditions for the solution existence are established. As applications we derive consequences for several special cases of variational inclusion problems, quasioptimization problems, equilibrium problems and implicit variational inequalities and show that they improve the results of some recent existing papers. 相似文献
3.
S. Kumagai 《Journal of Optimization Theory and Applications》1980,31(2):285-288
In Ref. 1, Jittorntrum proposed an implicit function theorem for a continuous mappingF:R
n ×R
m R
n, withF(x
0,y
0)=0, that requires neither differentiability ofF nor nonsingularity of
x
F(x
0,y
0). In the proof, the local one-to-one condition forF(·,y):A R
n R
n for ally B is consciously or unconsciously treated as implying thatF(·,y) mapsA one-to-one ontoF(A, y) for ally B, and the proof is not perfect. A proof can be given directly, and the theorem is shown to be the strongest, in the sense that the condition is truly if and only if. 相似文献
4.
5.
Alkaptonuria (AKU) is an ultra-rare disease caused by mutations in homogentisate 1,2-dioxygenase (HGD) enzyme, characterized by the loss of enzymatic activity and the accumulation of its substrate, homogentisic acid (HGA) in different tissues, leading to ochronosis and organ degeneration. Although the pathological effects of HGD mutations are largely studied, less is known about the structure of the enzyme, in particular the pathways for dioxygen diffusion to the active site, required for the enzymatic reaction, are still uninvestigated. In the present project, the combination of two in silico techniques, Molecular Dynamics (MD) simulation and Implicit Ligand Sampling (ILS), was used to delineate gas diffusion routes in HGD enzyme. A route from the central opening of the hexameric structure of the enzyme to the back of the active site trough the protein moiety was identified as the path for dioxygen diffusion, also overlapping with a transient pocket, which then assumes an important role in dioxygen diffusion. Along the route the sequence location of the missense variant E401Q, responsible for AKU development, was also found, suggesting such mutation to be conducive of enzymatic activity loss by altering the flow dynamics of dioxygen. Our in silico approach allowed also to delineate the route of HGA substrate to the active site, until now only supposed. 相似文献
6.
In the spirit of the Hamiltonian QR algorithm and other bidirectional chasing algorithms, a structure-preserving variant of
the implicit QR algorithm for palindromic eigenvalue problems is proposed. This new palindromic QR algorithm is strongly backward
stable and requires less operations than the standard QZ algorithm, but is restricted to matrix classes where a preliminary
reduction to structured Hessenberg form can be performed. By an extension of the implicit Q theorem, the palindromic QR algorithm
is shown to be equivalent to a previously developed explicit version. Also, the classical convergence theory for the QR algorithm
can be extended to prove local quadratic convergence. We briefly demonstrate how even eigenvalue problems can be addressed
by similar techniques.
D. S. Watkins partly supported by Deutsche Forschungsgemeinschaft through Matheon, the DFG Research Center Mathematics for key technologies in Berlin. 相似文献
7.
In this paper we extend some of our previous works on continua with stress threshold. In particular here we propose a mathematical model for a continuum which behaves as a non-linear upper convected Maxwell fluid if the stress is above a certain threshold and as a Oldroyd-B type fluid if the stress is below such a threshold. We derive the constitutive equations for each phase exploiting the theory of natural configurations (introduced by Rajagopal and co-workers) and the criterion of the maximization of the rate of dissipation. We state the mathematical problem for a one-dimensional flow driven by a constant pressure gradient and study two peculiar cases in which the velocity of the inner part of the fluid is spatially homogeneous. 相似文献
8.
9.
The present paper focuses on the analysis of two- and three-dimensional flow past a circular cylinder in different laminar flow regimes. In this simulation, an implicit pressure-based finite volume method is used for time-accurate computation of incompressible flow using second order accurate convective flux discretisation schemes. The computation results are validated against measurement data for mean surface pressure, skin friction coefficients, the size and strength of the recirculating wake for the steady flow regime and also for the Strouhal frequency of vortex shedding and the mean and RMS amplitude of the fluctuating aerodynamic coefficients for the unsteady periodic flow regime. The complex three dimensional flow structure of the cylinder wake is also reasonably captured by the present prediction procedure. 相似文献
10.
Omar Ramadan 《International Journal of Infrared and Millimeter Waves》2005,26(12):1757-1770
Unconditionally stable formulations of the anisotropic perfectly matched layer (APML) are presented for truncating double
negative (DNG) meta-material finite difference time domain (FDTD) grids. In the proposed formulations, the Z-transform theory
is employed in the alternating direction implicit FDTD (ADI-FDTD) scheme to obtain update equations for the field components
in the DNG meta-material domains. Numerical examples carried out in one dimensional Lorentzian type DNG meta-material domains
are included to show the validity of the proposed formulations. 相似文献