基于场景筛选的频谱需求预测算法

本文通过对业务数据、运维数据的挖掘分析,结合网络实际情况,提出了一种基于场景筛选的频谱需求计算方法(SSRA)。本文所提理论方法,结合我国实际情况及数据,对我国未来2020年频谱需求量进行了测算。     

Single PON network design with unconstrained splitting stages

A Passive Optical Network (PON) is a network technology for deploying access networks based on passive optical components. In a single PON access network, the client terminals are connected to a Central Office through optical splitters and interconnecting fibers where each splitter splits in equal parts the input optical signal coming from the Central Office over its different output fibers. In this paper, we consider PON topology solutions where the splitting ratio and the number of splitting stages are not constrained to a given target design but, instead, are decided based on the cost of the solutions. We present different Integer Linear Programming formulations to model this problem and provide computational results showing that the optimal solutions can be computed for realistic problem instances. In addition, we describe how the formulations can be adapted for the traditional PON topology approaches and present computational results showing that significant cost gains are obtained with the unconstrained splitting stage approach.     

典型非线性固定核函数时频分布的性能分析

传统的傅立叶变换无法满足对非线性、非平稳信号的分析,时频分析旨在构造一种时间和频率的密度函数,能够反映非平稳信号的时变特征,是非平稳信号分析的有力工具。文章讨论了魏格纳-威尔分布、伪平滑魏格纳-威尔分布及乔伊-威廉斯分布三种固定核函数时频分析方法的性能特征,进行计算机仿真,最后总结这三种分布在时频分辨率、抗干扰能力和信号适用性方面的优缺点。     

Heisenberg behavior of some carbon‐beryllium compounds: How well truncated‐CI approaches work

This works tries to establish the performance of truncated CI calculations on the evaluation of magnetic coupling parameters with respect to available FCI estimates on a set of carbon‐beryllium clusters. First‐, second‐ and third‐neighbor magnetic coupling constants have been evaluated and many body effective parameters as the cyclic terms. They result from the fitting of the low‐lying states to the eigenvalues of an extended Heisenberg Hamiltonian, involving not only two‐body isotropic terms but also cyclic terms. SDCI and DDCI calculations have been carried out and their performance compared with FCI ones. The impact of the basis set choice and size‐consistency errors have been explored. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011     

一个新分数阶超混沌系统及其混沌同步

给出了一个新的分数阶超混沌系统,利用严格数学理论实现了该分数阶超混沌系统的混沌同步,在同步过程中并未删除响应系统的非线性项,理论分析与仿真计算表明了同步方法的有效性. 关键词： 分数阶超混沌系统 混沌同步 非线性项     

New exact solutions to the high dispersive cubic–quintic nonlinear Schrödinger equation

The complete discrimination system method is employed to find exact solutions for a dispersive cubic–quintic nonlinear Schrödinger equation with third order and fourth order time derivatives. As a result, we derive a range of solutions which include triangular function solutions, kink solitary wave solutions, dark solitary wave solutions, Jacobian elliptic function solutions, rational function solutions and implicit analytical solutions. Numerical simulations are presented to visualize the mechanism of Eq. (1) by selecting appropriate parameters of the solutions. The comparison between our results and other's works are also given.     

基于校准k-ε模型的复杂地形流动数值模拟

准确计算风电场的内部流动对风电场的微观选址至关重要。求解雷诺平均NS方程(RANS)的模拟是当前模拟风电场内部流动的主要手段。湍流模型对模拟结果的准确性有很大影响。选取在工程中广泛应用的标准k-ε湍流模型进行研究。首先以平板地形为计算模型,探究入口边界条件、壁面方程、模型可调参数和对模拟流向均匀大气边界层的影响,获得平板地形下最优的模型可调参数设置。然后以三维山丘地形为计算模型,研究入口边界条件和源项对存在分离流动时复杂地形下的绕流模拟的影响。将得到的最优结果同实验结果对比,验证模拟方法的可行性,并给出添加源项的指导方法。