路由查找算法评价系统的设计与实现

路由查找是决定路由器报文转发能力的重要因素，近年来，为了提高路由查找的速度，研究人员提出了多种新的路由查找算法，本文首先提出了路由查找算法的评价标准，为了对查找算法进行全面评价，设计和实现了路由查找算法评价系统，并对主要的几种路由查找算法进行了分析评价。     

路由查找算法研究综述

随着Internet的迅猛发展,用于主干网络互联的核心路由器的接口速率已经达到了2.5Gbps～10Gbps.这一速率要求核心路由器每秒能够转发几百万乃至上千万个以上的分组.分组转发的重要一步就是查找路由表,因此快速的路由查找算法是实现高速分组转发的关键.路由查找需要实现最长前缀匹配.近年来,研究人员提出了多种路由查找算法,以提高查找性能.分析了路由查找问题及其难点,全面综述了各种查找算法,并对它们进行了详细的分析和比较,最后指出了进一步的研究方向.     

网格环境下一种有效的资源查找方法

在分布、异构的网格环境下，如何快速进行资源查找定位是影响网格计算性能的重要因素．该文对网格环境下已有资源查找方法进行了分析，指出了这些方法存在的不足，提出了基于路由转发(Routing-Transfer)机制的资源查找算法．该文中对这些资源查找方法进行了时间复杂度和空间复杂度分析，结果表明文中提出的路由转发算法的时间复杂度最小，其空间耗费可以容忍，是网格环境下一种有效的资源查找定位方法．     

基于动态混合查找的WSN自适应路由算法

针对无线传感器网络(WSN)需动态调整路由请求域的问题,提出一种基于动态混合查找的WSN自适应路由算法。该算法依据路由查找的返回状态,以圆柱形路由请求域的半径作为调整参数,利用折半查找和指数查找相结合的方法对路由请求域进行动态自适应调整。仿真结果表明,该算法在数据包投递率、路由开销和数据包平均时延上的性能均优于AODVjr路由算法。     

高速路由器中基于树型结构路由查找算法的研究与实现

本文在比较各种基于树型结构查找算法的基础上提出了一种改进的路由查找算法，该算法具有查找速度快、所需存储空间小、更新速度快、硬件实现简单等特点，能够满足10Gbps核心路由器环境的要求。     

基于TCAM的二级路由查找

功率消耗大是三态内容寻址存储器(TCAM)的主要缺点之一。根据TCAM的可配置特性，提出了基于TCAM的二级路由查找，大大降低了TCAM的功耗。给出了基于比特选择的二级路由查找方案并对其进行了性能分析。最后介绍了二级路由查找下的路由更新算法。     

基于前缀扩展的快速路由查找算法

该文对路由器中的快速路由查找算法进行了研究。针对路由查找算法在查找速度、算法空间复杂度以及插入和删除表项的难度算方法存在的问题,提出了一种快速路由查找算法。该算法通过构造两级索引表结构来减小路由查找的访存次数以提高查找速度;利用前缀扩展的特性并采用特殊的数据结构来构建索引表,能支持动态插入、删除和更新路由;采用压缩技术对二级索引表进行压缩,从而大大减小了路由所需的存储空间。该算法最多四次访存,最少两次访存就完成一次路由查找。由于采用了压缩方法,所需存储空间很小,该算法不仅适合于软件实现,也适合于硬件实现。查找速度快、存储空间小并支持动态插入和删除是该算法的主要特点。     

高速地址Cache-散列表的应用

路由交换机对IP进行转发时，一般需要查找路由表获得转发路径。但在网络层上实现此功能是一个耗费时间的过程，特别是在一个比较大网络中进行路由交换时，其路由表会相当庞大，路由查找就成了交换机的一个瓶颈。为了解决这个问题，可采用高速地址缓存来加快路由查找过程。其基本思路是第一次IP包的路由确定后，以后的包直接转发，在具体实现中，需要有一个高速地址缓存为暂存路由信息，以便使后续的到达同一目的地的IP包块通过路由交换机。文章对高速地址缓存的实现进行了探讨。     

路由查表算法及性能分析

由于Internet的流量迅速增长，一般的核心路由器都要能够达到每秒钟G比特的转发速率，快速的路由查表算法是实现高速分组转发的关键。文中分析了由于CIDR的产生导致路由查表算法变化的问题，详细介绍了各种查找算法并对各算法的查找速度、更新复杂度、内存消耗等进行了性能分析和比较，最后给出了查表算法适用于何种情况的结论。     

TCAM在高速路由查找中的应用及其FPGA实现

当前随着网络带宽的不断增加，对路由器转发速度的要求也越来越高。如何进行路由的快速查找目前成为限制报文快速转发的瓶颈，为了解决这一问题比较流行的方式是采用TCAM器件进行路由的快速查找。本文详细介绍了TCAM器件在高速路由查找中的应用及其管理算法，同时重点给出了TCAM器件的FPGA实现。     

On the seasonal inconsistency of altimeter wind speed algorithms

Altimeter-derived wind speed has become a major source of data for climatological studies in recent years, thanks to the continued success of several operational missions. A variety of algorithms have been proposed to convert altimeter-measured radar cross-section to sea surface wind speed. The performance of these algorithms determines, to a large extent, the quality of the estimated wind speeds and, consequently, their suitability for various applications. In this study, 6 years of coincident TOPEX altimeter and JMA (Japan Meteorological Agency) buoy wind speeds from January 1993 to December 1998 were used to evaluate the seasonal consistency of three algorithms. Our results demonstrate that seasonal inconsistency is a common problem associated with altimeter wind speed algorithms. A biased pattern of seasonal wind speed variation is inevitable as long as available altimeter algorithms are used in their present forms. The type and extent of the distortion depend on specific algorithm and actual wind speed distribution. It is shown that such a systematic error may have a number of potential consequences, which could undermine some of the geophysical interpretations concerning the seasonality of global and regional wind climate.     

On the textured iterative algorithms for a class of tridiagonallinear equations

The textured, iterative approximation algorithms are a class fast linear equation solvers and differ from the classical iterative algorithms fundamentally in their approximations of system matrices. The textured approach uses different approximations of a system matrix in a round-robin fashion while the classical approaches use a single fixed approximation. It therefore has a better approximation of system matrix and a potentially faster speed. In this paper we prove that the convergent speed of the textured iterative algorithms for linear equations with a class of tridiagonal system matrices is strictly faster than the corresponding classical iterative algorithms. We also give the spectral radii of the textured iterative and classical algorithms for this class of linear equations. These results provide some insights and theoretical supports for the textured iterative algorithms     

两个快速的完全的并行细化算法

本文提出了两个并行细化算法ＦＰＴＡ１和ＦＰＴＡ２，并对算法的正确性给出了证明。通过一些典型图像模式的处理，对这两处算法和目前几个流行的并行累化算法进行了比较。结果表明，本文提出的算法，在细化质量和执行速度等方面，都具有明显的优点。     

基于深度学习的目标检测技术综述

目标检测是计算机视觉领域中的研究热点.近年来,目标检测的深度学习算法有突飞猛进的发展.基于深度学习的目标检测算法大致可分为基于候选区域和基于回归两大类.基于候选区域的目标检测算法精度高,但是结构复杂,检测速度较慢.而基于回归的目标检测算法结构简单、检测速度快,在实时目标检测领域有较高的应用价值,然而检测精度相对略低.本文总结了基于深度学习的目标检测主流算法,并分析了相关算法的优缺点和应用场景.最后根据深度学习的目标检测算法中存在的困难和挑战,对未来的发展趋势做了思考和展望.     

On rolling back and checkpointing in time warp

In this paper, we present a family of three algorithms which serve to perform checkpoints and to roll back time warp. These algorithms are primarily intended for use in simulations in which there are a large number of LPs and in which events have a small computational granularity. Important representatives of this class are VLSI and computer network simulations. In each of our algorithms, LPs are gathered into clusters via algorithms which are application dependent. In order to examine the performance of our algorithms and to compare them to Time Warp, we made use of two of the largest digital logic circuits available from the ISCAS89 benchmark series of combinational circuits. The execution time, number of states saved, and maximal memory consumption were compared to the same quantities for time warp. Our results indicated that each of the algorithms occupies a different point in the spectrum of possible trade-offs between memory usage and execution time, ranging from substantial memory savings (at a comparable cost in speed) to memory savings and a comparable speed to time warp. Hence, an important benefit of our algorithms is the ability to trade off memory requirements with execution time     

High-speed,low-leakage integrated circuits: An evolutionary algorithm perspective

The markets today observe users having increasing demands on processing speed and energy consumption of their mobile devices. However, processing speed as well as functionality always comes at the expense of energy and thus limits, among other things, mobility and integration density. Recent technological developments allow for the simultaneous realization of slow, low-energy consuming as well as fast, high-energy consuming gates on the very same chip. In this respect, a particular design is an abstract optimization task for which this paper applies evolutionary algorithms. These algorithms are heuristic population-based search procedures that utilize certain mechanisms known from natural evolution. In comparison to currently available deterministic optimization procedures, the evolutionary algorithms achieved some energy savings of about 10–40% on standard ISCAS test problems, while still yielding the highest processing speed possible.     

DES_RSA及其混合算法的加密速度研究

为了在保证安全性的前提下提高大量数据加密的加密速度,本文通过DES和RSA算法的分析,针对DES算法密钥安全性差和RSA算法加密速度慢的问题,提出DES和RSA混合算法.对比DES和RSA两种算法加密所需时间,就RSA算法耗时长的问题,通过几种可行的大素数判定算法分析,提出改进的大素数判定算法.在保证安全性的前提下,将改进的大素数判定算法应用于RSA算法中,提升了加密速度.由于改进算法加密速度仍远差于DES算法,不适合大量数据加密.因此在兼顾安全性与加密速度的基础上,提出DES和RSA混合加密算法.经分析该算法综合了前两种算法的优点,是一种理想的加密算法.     

基于单线圈输出量的速度估计算法综述

先进的交通管理系统和旅行者信息系统的迅速发展,引起对交通速度估计测量一种需要。然而对于铺设大量单线圈的快速路网来说,交通速度并不能直接从单线圈检测器测量出来。因此许多研究学者针对如何从单线圈的输出量估计出交通速度展开了研究。该文结合国内外的研究情况给出了算法的分类,并总结了算法存在的问题和可能开展的研究方向。