排序方式: 共有34条查询结果,搜索用时 15 毫秒
11.
Konstantin Avrachenkov Vivek Borkar 《Journal of Computational and Applied Mathematics》2010,234(11):3075-3090
A random walk can be used as a centrality measure of a directed graph. However, if the graph is reducible the random walk will be absorbed in some subset of nodes and will never visit the rest of the graph. In Google PageRank the problem was solved by the introduction of uniform random jumps with some probability. Up to the present, there is no final answer to the question about the choice of this probability. We propose to use a parameter-free centrality measure which is based on the notion of a quasi-stationary distribution. Specifically, we suggest four quasi-stationary based centrality measures, analyze them and conclude that they produce approximately the same ranking. 相似文献
12.
We consider the effectiveness of targeted vaccination at preventing the spread of infectious disease in a realistic social network. We compare vaccination strategies based on no information (random vaccination) to complete information (PageRank) about the network. The most effective strategy we find is to vaccinate those people with the most unvaccinated contacts. However, this strategy requires considerable information and computational effort which may not be practical. The next best strategies vaccinate people with many contacts who in turn have few contacts. 相似文献
13.
This article presents a survey of techniques for ranking results in search engines, with emphasis on link-based ranking methods
and the PageRank algorithm. The problem of selecting, in relation to a user search query, the most relevant documents from
an unstructured source such as the WWW is discussed in detail. The need for extending classical information retrieval techniques
such as boolean searching and vector space models with link-based ranking methods is demonstrated. The PageRank algorithm
is introduced, and its numerical and spectral properties are discussed. The article concludes with an alternative means of
computing PageRank, along with some example applications of this new method. 相似文献
14.
Ying Bao Zi-hu Zhu 《应用数学学报(英文版)》2006,22(3):517-528
In this paper we discuss three important kinds of Markov chains used in Web search algorithms-the maximal irreducible Markov chain, the miuimal irreducible Markov chain and the middle irreducible Markov chain, We discuss the stationary distributions, the convergence rates and the Maclaurin series of the stationary distributions of the three kinds of Markov chains. Among other things, our results show that the maximal and minimal Markov chains have the same stationary distribution and that the stationary distribution of the middle Markov chain reflects the real Web structure more objectively. Our results also prove that the maximal and middle Markov chains have the same convergence rate and that the maximal Markov chain converges faster than the minimal Markov chain when the damping factor α 〉1/√2. 相似文献
15.
《Stochastic Processes and their Applications》2020,130(4):2312-2348
16.
In this paper, we propose and analyze GMRES-type methods for the PageRank computation. However, GMRES may converge very slowly or sometimes even diverge or break down when the damping factor is close to 1 and the dimension of the search subspace is low. We propose two strategies: preconditioning and vector extrapolation accelerating, to improve the convergence rate of the GMRES method. Theoretical analysis demonstrate the efficiency of the proposed strategies and numerical experiments show that the performance of the proposed methods is very much better than that of the traditional methods for PageRank problems. 相似文献
17.
18.
Francisco Pedroche Regino Criado Julio Flores Esther García Miguel Romance 《Mathematical Methods in the Applied Sciences》2020,43(14):8158-8176
In this paper, some results concerning the PageRank versatility measure for multiplex networks are given. This measure extends to the multiplex setting the well-known classic PageRank. Particularly, we focus on some spectral properties of the Laplacian matrix of the multiplex and on obtaining boundaries for the ranking value of a given node when some personalization vector is added, as in the classic setting. 相似文献
19.
20.
Google 创始人sergey Brin 和Lawrence Page 把万维网搜索算法PageRank 定义成某个非周期不可约马氏链的唯一平稳分布.本文讨论了万维网搜索算法中使用的两个重要的马氏链-maximal 不可约马氏链和minimal 不可约马氏链-收敛到平稳分布的收敛速度.结果表明,在阻尼因子α>1/2~(1/2)时,maximal 马氏链比minimal 马氏链的收敛速度快.本文也给出了minimal 马氏链k 步转移矩阵的表达式,及其平稳分布关于参数α的各阶导数和Maclaurin 级数展开. 相似文献