三层交换机的快速配置恢复方法研究及实现

社会经济的发展推动了我国网络技术的发展,特别是三层交换机的广泛使用,为了提高三层交换机配置恢复的速度与效率,提高传统的配置恢复速率,可以通过采用二进制格式的配置文件来进行配置恢复工作。就三层交换机的快速配置恢复方法进行研究和探讨,并提出一些可供参考的意见和措施。     

基于成组技术的夹具快速配置研究

提出了基于成组技术的夹具快速配置系统体系结构,研究贯穿了零件分类编码、夹具设计需求和夹具元件库的建立等方面.采用基于成组技术的方法开发了夹具快速配置系统,支持企业对夹具快速设计.     

基于规则格网的地图等高线快速追踪算法

地图中等高线是表达地貌起伏形态的有效方法。利用已知点高程数据内插等高点是构建等高线的关键,本文提出了一种基于规则格网通过插值决速追踪等高点的算法,研究了等高线的平滑算法,该方法可应用于类似等值线的追踪和建立。     

重配置系统中基于组件的协议栈管理

考虑到未来移动通信设备能够支持多种接入标准和协议栈,而且协议栈重配置能力将会成为一种促进异构系统融合的关键驱动技术,本文研究了协议栈重配置系统的协议组件的管理,并基于组件化的协议框架,提出了一套管理协议组件的方法.为了使得协议栈能够针对不同的通信情况对自身进行配置调整,从而达到为每个无线业务定制最佳协议栈的目标,提出了一种针对协议组件的评估机制和一种在网络协议组件库中寻找最佳组件来替代当前系统中运行效果不佳的协议组件的协议栈优化方法.上述机制和方法的最终目标是通过灵活的协议栈配置为用户提供最佳的业务体验.     

可重配置的嵌入式CAN总线系统的设计与实现

在基于 CAN 总线的嵌入式系统中,采用 ARM7TDMI 内核的 16/32 位 RISC MCU 是独立的地址和数据总线,而 CAN 总线控制器是利用地址锁存信号 ALE 来复用数据地址总线。为了实现MCU 与 CAN 总线的透明连接,提出利用可重配置技术,在一块 FPGA 上实现 MCU 与 CAN 控制器之间总线的转换。软件仿真和实际应用表明,可重配置模块能够很好地满足时序要求,真正实现了透明的无缝传输。     

地图线状要素注记自动配置的算法与实现

本文探讨了线状要素自动注记的几个关键问题,提出利用注记参考线计算线状要素的注记定位线,同时提出反Douglas算法进行注记参考线的动态分段,利用动态分段的结果集获取线状要素的平滑位置作为候选注记位,在此基础上获取注记中每个字的备选位置以及评分,最后采用禁忌算法解决注记之间的冲突,从而较好地解决了线状要素注记不可见或表达模糊的问题,实现了自动注记输出的完整性和美观性的统一。     

ODFT的分离基快速算法

ODFT的快速算法是应用多项式变换计算二维循环卷积与二维DFT的关键之一。本文提出了ODFT的分离基快速算法,给出了信号流图,分析了计算复杂性,并和ODFT的其他快速算法作了比较。对实序列的ODFT分离基快速算法,也相应作了探讨。本文算法所需的实乘次数与其它算法相同,而实加次数比其他算法都少。而且可进行原位计算,结构规则,易于实现。     

n重积分优化二次式数值算法

本文采用三等分法给出n重积分的优化二次式数值积分法,它在迭代计算过程中免去了重复计算,加速达到近似值精度,并给出了绝对误差估计式。     

语音时长调整快速算法

针对目前使用的时域语音时长调整算法计算量大、难以保证实时性的问题,深入研究语音时长调整算法的原理,并结合语音自身的短时平稳性、准周期特性和信号的频率特性,提出三种解决途径（只搜索叠加部分原则、隔点搜索原则、隔点计算相似性原则）,在保证语音质量不降低的同时,大幅减少冗余的计算量,实验结果表明,该方法调整后的语音质量高、计算速度快,通过与原始算法的对比证明了以上结论,该方法能广泛应用于实际中,尤其是应用于实时性要求较高的场合。     

快速成型技术中分段算法的研究综述

在快速成型技术中,模型分段处理是分层处理的前一步骤,对分段算法进行研究十分有必要.为此,对快速成型技术中的分段算法进行总结,主要从人机交互分段和自动分段两方面展开.对于人机交互分段算法,主要从根据不同成型要求进行分段方面展开叙述;对于自动分段算法,主要介绍了体素化分段算法、特征识别式分段算法、多目标优化分段算法和聚类式...     

一种基于P圈的ASON节点保护方案

在研究自动交换光网络（ASON）中发生节点故障时的保护方法的基础上,提出了一种针对节点故障使用P圈实现业务保护的方案,同时提出了一种在确保发生单链路故障时实现100％业务恢复率的基础上进行节点故障保护的启发式算法,并通过OPNET软件搭建的ASON仿真平台,在泛欧COST239网络拓扑和北美NSFnet网络拓扑上,采用静态业务模型对该算法进行了仿真评估。仿真结果证明,该算法在拥有故障业务快速恢复能力的同时,相比已有算法具有更低的资源冗余度。     

一种支持服务扩展与重组的网络设备体系结构

针对目前网络设备中各种服务不统一的问题,基于可编程网络处理器的特点,提出了一种服务一体化的网络设备体系结构.把防火墙、VPN、负载均衡等设备对数据包的处理统一表示为一组规则与行为的集合,对数据包先统一分类,再做相应处理,从而把多种网络服务集成到一起;设计了基于Hash的分类规则表,实现了运行期更新规则表以及向数据平面载入执行代码,使功能可以动态扩展;设计了并行部署与处理网络服务的系统硬件体系结构,实现了基于IXP2400处理器的原型系统.实验证明,这种体系结构使各种服务可以方便地重组与扩展,避免了各种设备对包的重复分类,降低了网络时延,采用并行处理结构后,解决了因服务的增加而导致的性能下降的问题.     

A morphology proposal in commercial-off-the-shelf reconfigurable machine tools

Global manufacturing is continuously facing changing demands, the unpredictable part family supply that a machine tool user has to deal with needs varying machine morphologies. The reconfigurable manufacturing system paradigm proposes the need for the right capacity, for the right demand with an economical ramp-up period. The machinist needs to have a systematic manner of configuring the machines, given a set of modules that will be configured and reconfigured for the various demands in the lifespan of a manufacturing system. In this article, the author proposes how the machinist can go about identifying the different morphologies in advance. The method is simple and user-friendly in consideration of the main users who may have basic skills being deficient in sophistication and complexity; it further assists in the determination of the capability the manufacturer has with the available modules.     

Capacity-efficient strategy for 100% dual-failure restorability in optical mesh networks utilising reconfigurable p-cycles and a forcer filling concept

The problem of achieving 100% dual-failure restorability utilising reconfigurable p-cycle mechanisms has been investigated via three different p-cycle mechanisms derived from the integer linear programming model; complete-repair (CRP), incremental-repair (IRP) and dynamic-repair (DRP). An enhanced 100% dual-failure restoration mechanism is proposed, designated as modified DRP with forcer filling concept (MDRP/wFF), in which network protection is achieved using only reconfigurable span-protecting p-cycles without the addition of path-segment-protecting p-cycles as in DRP. As a result, the overhead incurred in differentiating between the two p-cycles becomes non-existent upon network restoration. Furthermore, a FF concept is employed to reduce the amount of spare capacity required to restore the network. The performance of the MDRP/wFF scheme was benchmarked against that of the CRP, IRP and DRP mechanisms. The simulation results show that MDRP/wFF achieves a performance tradeoff among CRP, IRP and DRP in terms of its spare capacity requirements and average number of reconfigured spans during the reconfiguration process [designated as average reconfiguration overhead (ARO)]. The MDRP/wFF scheme was found to have a lower spare capacity requirement but incurs some additional ARO compared with DRP.     

A fast algorithm for three-dimensional electrostatics analysis: fast Fourier transform on multipoles (FFTM)

In this paper, we propose a new fast algorithm for solving large problems using the boundary element method (BEM). Like the fast multipole method (FMM), the speed-up in the solution of the BEM arises from the rapid evaluations of the dense matrix–vector products required in iterative solution methods. This fast algorithm, which we refer to as fast Fourier transform on multipoles (FFTM), uses the fast Fourier transform (FFT) to rapidly evaluate the discrete convolutions in potential calculations via multipole expansions. It is demonstrated that FFTM is an accurate method, and is generally more accurate than FMM for a given order of multipole expansion (up to the second order). It is also shown that the algorithm has approximately linear growth in the computational complexity, implying that FFTM is as efficient as FMM. Copyright © 2004 John Wiley & Sons, Ltd.     

A numerical study of pulsatile blood flow in an eccentric catheterized artery using a fast algorithm

The pulsatile blood flow in an eccentric catheterized artery is studied numerically by making use of an extended version of the fast algorithm of Borges and Daripa [J. Comp. Phys., 2001]. The mathematical model involves the usual assumptions that the arterial segment is straight, the arterial wall is rigid and impermeable, blood is an incompressible Newtonian fluid, and the flow is fully developed. The flow rate (flux) is considered as a periodic function of time (prescribed). The axial pressure gradient and velocity distribution in the eccentric catheterized artery are obtained as solutions of the problem. Through the computed results on axial pressure gradient, the increases in mean pressure gradient and frictional resistance in the artery due to catheterization are estimated. These estimates can be used to correct the error involved in the measured pressure gradients using catheters.     

A wideband fast multipole algorithm for two‐dimensional volume integral equations

This paper describes a wideband fast multipole algorithm (FMA) for the computation of two‐dimensional volume integral equations. Our previous paper presented the wideband FMA by switching between the diagonal and non‐diagonal forms according to cell size and required accuracy. In order to improve the efficiency of the algorithm, we use interpolation and filtering techniques. Moreover, we introduce a simple and efficient way to store sequences of the special functions and their discrete Fourier transforms. Numerical examples show that the computational and memory complexities are reduced from O(N²) to O(N), where N is the number of square elements followed by the discretization of the volume integral equations. The computation results show very good agreement with the analytical solutions. We present some numerical results for the computation of scattering from a cylindrical object with sharp edges and a Gaussian‐like inhomogeneous cylinder. Copyright © 2008 John Wiley & Sons, Ltd.     

大规模动力系统高精度増维精细积分方法快速算法

考虑高精度増维精细积分法求解大规模动力系统快速算法。为提高増维精细积分方法求解大规模动力系统精度,将非齐次项近似为高阶多项式,形成高精度増维精细积分方法;为减少计算时间、提高计算效率,提出高精度増维精细积分方法快速算法。算例表明,通过提高非齐次项近似阶数可显著提高计算精度,快速算法可使计算效率呈量级提高,高精度快速算法适合大规模动力系统长时间推进计算。     

抗毁性WDM网状光网络中的P圈快速构造算法

p圈法是抗毁性网状WDM光网络中一种十分优秀的保护算法,在p圈配置到网状光网络的过程中,圈构造算法是设计的第一步.文中提出了一种快速圈挖掘算法(FCMA),本算法基于k-最短路由算法构造最小p图,通过圈扩展算法获得更多性能优良圈,文中给了启发式算法的具体步骤.通过计算机仿真表明,该算法实现快速圈构造,性能优于其它同类算法,适合网状光网络中的p圈快速构造.     

一种适用于流数据分析的快速EMD算法

采用具有局域控制特性的B样条函数直接拟合均值线,采用局域标准差终止准则判断原型模态函数（Proto-mode Function,PMF）的对称性,得到一种适用于流数据分析的快速经验模态分解（Empirical Mode Decomposition,EMD）算法。相比经典EMD算法,该快速算法不仅时间复杂度和空间复杂度均有所下降,而且分解精度基本维持不变。该快速算法适用于战场侦察传感网等流数据分析场合,实时性好,能够得到与序列等长的连贯本征模态函数（Intrinsic Mode Function,IMF）。