一种混合优化算法及其收敛性证明

针对改进的混沌优化方法和Alopex算法的特性，将改进的Alopex算法嵌入到改进的混沌优化算法中，提出一种混合优化算法，此算法充分发挥了改进的Alopex算法的快速搜索能力和改进的混沌优化方法细致寻优的特性，提高了算法的收敛速度，避免了优化算法陷入局部最优；同时对改进的混沌优化算法和混合优化算法的收敛性进行了证明，仿真结果表明了算法的有效性。     

一种新直线算法的探索

对传统直线算法进行了详细的分析，然后从传统直线算法的另外一个角度对直线生成算法做出了新的探索，改变了传统算法中直线像素点的查找方式，提出了一种新的查找最佳像素点的方法，与传统方法相比，新算法节点的查找方式的突出特点是按段进行的，为了提高算法的性能，对算法进行了增量优化。文章最后对两种算法进行速度比较发现，本算法在速度上优于传统直线生成算法。     

改进相关矩阵估计的LMS牛顿算法分析与仿真

在LMS牛顿算法中权值的更新采用了输入信号矢量的相关矩阵估计，不同的估计方法对算法的性能影响很大，该文分析了一种改进相关矩阵估计的LMS牛顿算法，该算法通过对LMS牛顿算法中的相关矩阵采用改进的指数加权估计，大大提高了算法的性能，同时维持了适中的计算复杂度。此外，还比较了LMS牛顿算法与RLS算法，从原理上说明了它们的密切联系；指出算法改善性能的关键在于变步长特性，即步长随着时间增加而逐渐变小，使得算法既可以保持较快的收敛速度，又获得了较小的失调。算法在智能天线中的仿真结果表明，该算法具有比常规LMS牛顿算法更优的性能。     

SHITS:一种基于超链接和内容的网页排序方法

回顾了当前应用于大型搜索引擎的主流网页排序算法，对其中的ARC算法进行了改进，提出了一种基于超链接和内容的网页排序算法--SHITS（Similarity—HITS）算法．SHITS算法用超链接所引用的网页内容代替了ARC算法中所采用的锚文本来评估该超链接的重要性，这一改进不仅提高了算法区分链接重要性的能力，也避免了对大量锚文本内容的分析．通过与相关算法的对比实验，结果表明：SHITS算法网页排序的准确率明显优于其它算法．此外，SHITS算法也具有较好的效率：计算代价小于ARC算法，与HITS算法相当．     

Euclid算法及扩展在密码学中的研究和应用

信息安全是网络时代的焦点，密码技术是信息安全的核心．而算法是密码学的精髓。文中研究了基于因数分解的Euclid算法和扩展Euclid算法，包括算法的基本原理、算法流程及编程实现。分析了Euclid算法的算法复杂性，介绍了Etrclid算法在RsA和Affine Cipher密码系统中的应用，最后指出了该算法存在的缺陷和算法需要改进的方向。     

变尺度法与Huang族公式

变尺度算法是求解无约束优化问题的有效而著名的算法，算法易于实现，计算量较小，并形成了完整的算法体系，对工程应用有重要的影响。文中简述了变尺度算法的基本思想，介绍了Huang算法族和Broyden族及它们的基本性质，分析比较了近年来对变尺度算法不同角度的研究。通过数值实验证明了变尺度算法的有效性。     

覆盖聚类算法的应用研究

聚类算法是数据挖掘的核心技术。介绍了几类主要的传统聚类算法，给出了每类算法的基本概念、基本原理、各类表示聚类的算法以及这些算法的特征。然后再提出了一种新的聚类算法——覆盖聚类算法，给出了该算法的具体步骤，并对模糊聚类算法和该算法用实验的方式进行比较，证明了覆盖聚类算法的可行性和有效性。最后分析了当前聚类算法存在的问题和发展方向。     

分布式系统中自然联结的优化算法分析

讨论了几种提高自然联结效率的算法。并比较了它们的效率和性能，其中包括经典的Ｍｅｒｇｅ－ｓｃａｎ算法，Ｎｅｓｔｅｄ算法，Ｈａｓｈ－ｊｏｉｎ算法，以及改进的ＪＭ１，ＪＭ２算法，Ｄｉｓｔｒｉｂｕｔｉｖｅｊｏｉｎ算法，ＪｏｉｎＦｒａｇｍｅｎｔａｔｉｏｎ算法，ＧＲＡＣＥＨａｓｈ－ｊｏｉｎ算法和ＨｙｂｒｉｄＨａｓｈ－ｊｏｉｎ算法。这些算法没有绝对的优势，在具体的应用环境下，可根据实际情况采用最合适的优化算法。     

工程图纸输入与自动识别的改进细化算法

系统地介绍了两种典型的细化算法OPTA算法和Hilditch算法的原理和计算机实现，分析了OPTA算法和Hilditch算法的性能与不足，并提出了一种改进的Hilditch细化算法。该算法通过借鉴OPTA算法中的模板方法有效地减小了图像骨架偏移和毛刺的影响，经实验结果观察，改进的算法使图像细化结果得到较大改善。     

基于Min-Min改进后的网格调度算法

在对于网格计算中现有的任务调度算法的研究基础上，仔细分析了调度算法中最经典的Min-min算法，指出了该算法中所存在的负载不平衡的缺点，并在该算法的基础上提出了一个改进模型来有效的平衡负载，同时给出了相应的Balance-Min-Min算法。最后采用SimGrid工具包对所提出的算法进行仿真，验证了算法的合理性和高效性。     

归约算法统一描述

归约算法在并行计算中应用广泛,目前有很多归约算法应用于不同的情形。这些归约算法各不相同, 逻辑拓扑是 造成区别的关键 。为了统一描述归约算法,揭示它们的共性,给出了一个逻辑拓扑的定义及其性质。在此基础上,给出了归约算法的统一描述,以利于对归约算法的理解,从而设计适应不同应用和环境的归约算法。该描述也可视为可集成不同语义的归约算法框架,从而有助于设计具有新语义的归约算法。本质上,该统一描述是一个归约算法形式定义,有助于验证归约算法的正确性。     

Second-Level Algorithms,Superrecursivity, and Recovery Problem in Distributed Systems

In this paper, we analyze network recovery algorithms, which allow computer networks to properly function in spite of failures. In this analysis, we use methods and tools of the theory of super-recursive algorithms. The concept of algorithm of the second level is introduced and studied. It is demonstrated that although the main components of various check-point/recovery algorithms are recursive algorithms, check-point/recovery algorithms, as a whole, are super-recursive second-level algorithms. Treating network recovery algorithms as second level algorithms is oriented at developing more powerful algorithms by combining existing ones in a common schema.     

IPSec VPN的性能分析

VPN的性能与加密算法，认证算法和网络环境有关。计算表明，加密算法的吞吐量只有认证算法吞吐量的10％－35％，因此，加密算法对VPN性能的影响比认证算法对VPN性能的影响大，提高加密和认证算法的吞吐量，对提高高带宽网络VPN的性能具有明显的效果。     

A matrix-algebraic formulation of distributed-memory maximal cardinality matching algorithms in bipartite graphs

We describe parallel algorithms for computing maximal cardinality matching in a bipartite graph on distributed-memory systems. Unlike traditional algorithms that match one vertex at a time, our algorithms process many unmatched vertices simultaneously using a matrix-algebraic formulation of maximal matching. This generic matrix-algebraic framework is used to develop three efficient maximal matching algorithms with minimal changes. The newly developed algorithms have two benefits over existing graph-based algorithms. First, unlike existing parallel algorithms, cardinality of matching obtained by the new algorithms stays constant with increasing processor counts, which is important for predictable and reproducible performance. Second, relying on bulk-synchronous matrix operations, these algorithms expose a higher degree of parallelism on distributed-memory platforms than existing graph-based algorithms.We report high-performance implementations of three maximal matching algorithms using hybrid OpenMP-MPI and evaluate the performance of these algorithm using more than 35 real and randomly generated graphs. On real instances, our algorithms achieve up to 200 × speedup on 2048 cores of a Cray XC30 supercomputer. Even higher speedups are obtained on larger synthetically generated graphs where our algorithms show good scaling on up to 16,384 cores.     

Parametric Evaluation of Routing Algorithms in Network on Chip Architecture

Considering that routing algorithms for the Network on Chip (NoC) architecture is one of the key issues that determine its ultimate performance, several things have to be considered for developing new routing algorithms. This includes examining the strengths, capabilities, and weaknesses of the commonly proposed algorithms as a starting point for developing new ones.
Because most of the algorithms presented are based on the well-known algorithms that are studied and evaluated in this research. Finally, according to the results produced under different conditions, better decisions can be made when using the aforementioned algorithms as well as when presenting new routing algorithms. In this research, we first describe the existing algorithms include: XY, YX, Odd- Even and DyAD. We then evaluate each of the routing algorithms which naturally have their own strengths and weaknesses under different conditions. In the first scenario, based on the criteria of average latency, average throughput and average energy consumption in determining the final performance of the network on the chip, we show the algorithms in terms of their performance by deterministic and adaptive routing algorithms. In the second scenario, we evaluate the algorithms based on the network size and the number of cores on the chip. As a result, these algorithms can make better decisions when using these algorithms as well as when presenting new routing algorithms, considering the results produced under different condition.     

IP报文分类算法概述

Internet的高速发展要求提供高性能的P流分类算法以更好地为防火墙、QoS、流量工程、资源预留、网络地址转换等提供服务。由于IP报文分类算法的多域特征,因此其具有相当的难度。研究者提出了很多报文分类算法,本文将这些算法概括为5类：基于Trie树的算法、基于空间分割的算法、启发式算法、基于硬件实现的算法和其他算法,并对IP报文分类算法的思想、原理和过程进行了介绍和分析,说明了这些算法之间的联系,并对这些算法在搜索和更新的时间性能、空间性能、适用性范围和优缺点等进行了分析和比较。作为总结,本文还对IP报文分类算法研究的方法和趋势进行了分析和总结。     

Study on enhanced Karnik–Mendel algorithms: Initialization explanations and computation improvements

Computing the centroid of an interval type-2 fuzzy set is an important operation in a type-2 fuzzy logic system, and is usually implemented by Karnik–Mendel (KM) iterative algorithms. By connecting KM algorithms and continuous KM algorithms together, this paper gives theoretical explanations on the initialization methods of KM and Enhanced Karnik–Mendel (EKM) algorithms, proposes exact methods for centroid computation of an interval type-2 fuzzy set, and extends the Enhanced Karnik–Mendel (EKM) algorithms to three different forms of weighted EKM (WEKM) algorithms. It shows that EKM algorithms become a special case of the WEKM algorithms when the weights of the latter are constant value. It also shows that, in general, the weighted EKM algorithms have smaller absolute error and faster convergence speed than the EKM algorithms which make them very attractive for real-time applications of fuzzy logic system. Four numerical examples are used to illustrate and analyze the performance of WEKM algorithms.     

Self-protected quantum algorithms based on quantum state tomography

Only a few classes of quantum algorithms are known which provide a speed-up over classical algorithms. However, these and any new quantum algorithms provide important motivation for the development of quantum computers. In this article new quantum algorithms are given which are based on quantum state tomography. These include an algorithm for the calculation of several quantum mechanical expectation values and an algorithm for the determination of polynomial factors. These quantum algorithms are important in their own right. However, it is remarkable that these quantum algorithms are immune to a large class of errors. We describe these algorithms and provide conditions for immunity.      

A new taxonomy of sublinear right-to-left scanning keyword pattern matching algorithms

A new taxonomy of sublinear (multiple) keyword pattern matching algorithms is presented. Based on an earlier taxonomy by the second and third authors, this new taxonomy includes not only suffix-based algorithms, but also factor- and factor-oracle-based algorithms. In particular, we show how suffix-based (Commentz-Walter like), factor- and factor-oracle-based sublinear keyword pattern matching algorithms can be seen as instantiations of a general sublinear algorithm skeleton. During processing, such algorithms shift or jump through the text in a forward or left-to-right direction, and read backward or right-to-left starting from positions in the text, i.e. they read suffixes of certain prefixes of the text. They use finite automata for efficient computation of string membership in a certain language. In addition, we show shift functions defined for the suffix-based algorithms to be reusable for factor- and factor-oracle-based algorithms. The taxonomy is based on deriving the algorithms from a common starting point by adding algorithm and problem details, to arrive at efficient or well-known algorithms. Such a presentation provides correctness arguments for the algorithms as well as clarity on how the algorithms are related to one another. In addition, it is helpful in the construction of a toolkit of the algorithms.     

可扩展报文分类算法研究与评测

针对报文分类算法的可扩展性,深入分析了典型可扩展报文分类算法的时间、空间复杂度;基于ClassBench工具集开发出可扩展报文分类算法评测系统,利用该系统对典型算法在不同模拟场景下进行评测,并对各算法的性能差异和适用条件进行了系统分析。最后,对今后可扩展报文分类算法的发展趋势作出了展望。