The computational complexity of recognizing permutation functions

Let 05_Article_BF01277957_TeX2GIFIE1.gif" alt=" $$\mathbb{F}_q $$ " align="middle" border="0"> be a finite field withq elements and 05_Article_BF01277957_TeX2GIFIE2.gif" alt=" $$f \in \mathbb{F}_q \left( x \right)$$ " align="middle" border="0"> a rational function over 05_Article_BF01277957_TeX2GIFIE3.gif" alt=" $$\mathbb{F}_q $$ " align="middle" border="0"> . No polynomial-time deterministic algorithm is known for the problem of deciding whetherf induces a permutation on 05_Article_BF01277957_TeX2GIFIE4.gif" alt=" $$\mathbb{F}_q $$ " align="middle" border="0"> . The problem has been shown to be in co-R 05_Article_BF01277957_TeX2GIFIE5.gif" alt=" $$ \subseteq $$ " align="middle" border="0"> co-NP, and in this paper we prove that it is inR 05_Article_BF01277957_TeX2GIFIE6.gif" alt=" $$ \subseteq $$ " align="middle" border="0"> NP and hence inZPP, and it is deterministic polynomial-time reducible to the problem of factoring univariate polynomials over 05_Article_BF01277957_TeX2GIFIE7.gif" alt=" $$\mathbb{F}_q $$ " align="middle" border="0"> . Besides the problem of recognizing prime numbers, it seems to be the only natural decision problem inZPP unknown to be inP. A deterministic test and a simple probabilistic test for permutation functions are also presented.     

ReALE: A Reconnection Arbitrary-Lagrangian–Eulerian method in cylindrical geometry

This paper deals with the extension to the cylindrical geometry of the recently introduced Reconnection algorithm for Arbitrary-Lagrangian–Eulerian (ReALE) framework. The main elements in standard ALE methods are an explicit Lagrangian phase, a rezoning phase, and a remapping phase. Usually the new mesh provided by the rezone phase is obtained by moving grid nodes without changing connectivity of the underlying mesh. Such rezone strategy has its limitation due to the fixed topology of the mesh. In ReALE we allow connectivity of the mesh to change in rezone phase, which leads to general polygonal mesh and permits to follow Lagrangian features much better than for standard ALE methods. Rezone strategy with reconnection is based on using Voronoi tesselation machinery. In this work we focus on the extension of each phase of ReALE to cylindrical geometry. The Lagrangian, rezone with reconnection and remap phases are revamped to take into account the cylindrical geometry. We demonstrate the efficiency of our ReALE in cylindrical geometry on series of numerical examples.     

S1D13A05芯片在图形驱动中的硬件加速技术

简述了爱普生S1D13A05芯片的架构特征,并且介绍了其中的2D硬件加速引擎的工作模式和相关的寄存器设置,最后以VxWorks操作系统作为开发环境,基于风河公司WindML图形开发包,对S1D13A05芯片的图形驱动软件开发中的硬件加速技术进行了解析.     

汽车用深冲板“05”表面质量与冷轧工作辊的相关性

阐述了“05”表面质量与冷轧工作辊之间的相关性。冷轧工作辊的选材、表面处理和辊面缺陷的检测手段是提高汽车用深冲板“05”表面质量的必要条件。     

Efficient bulk-loading on dynamic metric access methods

This paper presents a new technique and two algorithms to bulk-load data into multi-way dynamic metric access methods, based on the covering radius of representative elements employed to organize data in hierarchical data structures.     

Asymptotic expansions for the location invariant moment-type estimator

In this paper, based on moment-type and location invariant Hill estimators, a new kind of location invariant moment-type extreme value index estimator is proposed. The weak and strong consistency of the estimator are discussed. The asymptotic expansion of the estimator and its distribution are also considered under second order regularly varying conditions. The asymptotic normality is employed to construct the confidence interval. Monte Carlo simulations are performed to compare the Hill estimator and the moment estimator in terms of mean squared error.     

Domain decomposition methods for the neutron diffusion problem

The neutronic simulation of a nuclear reactor core is performed using the neutron transport equation, and leads to an eigenvalue problem in the steady-state case. Among the deterministic resolution methods, simplified transport (S_PN$S{P}_N$) or diffusion approximations are often used. The MINOS solver developed at CEA Saclay uses a mixed dual finite element method for the resolution of these problems, and has shown his efficiency. In order to take into account the heterogeneities of the geometry, a very fine mesh is generally required, and leads to expensive calculations for industrial applications. In order to take advantage of parallel computers, and to reduce the computing time and the local memory requirement, we propose here two domain decomposition methods based on the MINOS solver. The first approach is a component mode synthesis method on overlapping subdomains: several eigenmodes solutions of a local problem on each subdomain are taken as basis functions used for the resolution of the global problem on the whole domain. The second approach is an iterative method based on a non-overlapping domain decomposition with Robin interface conditions. At each iteration, we solve the problem on each subdomain with the interface conditions given by the solutions on the adjacent subdomains estimated at the previous iteration. Numerical results on parallel computers are presented for the diffusion model on realistic 2D and 3D cores.     

一类修正的DY共轭梯度法及其全局收敛性

本文提出了一类求解无约束优化问题的修正DY共轭梯度法.算法采用新的迭代格式,每步迭代都可自行产生一个充分下降方向.采用Wolfe线搜索时,证明了全局收敛性.数值实验结果验证了算法是有效的.