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arXiv 0908.3436math.COmath.PR
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基于秩的连接导致幂律图

Rank-based attachment leads to power law graphs

Jeannette Janssen, Pawel Pralat

摘要:

我们调查的程度分布图生成模型的基础上基于排名的附件。在基于排名的连接中,所有顶点都根据排名方案进行排名。给定顶点的链接概率与其秩的-a次方成正比,其中a在(0,1)中。通过严格的分析,我们表明,基于秩的连接模型导致图的幂律度分布指数为1+1/a时,顶点根据他们的程度,他们的年龄,或随机选择的健身值排名。我们还调查的情况下,排名是基于每个顶点的初始排名,现有顶点的排名只改变,以适应新的顶点。在这里,我们得到一个尖锐的阈值幂律行为。只有当初始秩偏向低秩或随机均匀选择时,我们才得到指数为1+1/a的幂律度分布。这表明,在自然界中经常观察到的幂律度分布可以用基于等级的依恋方案来解释,该方案基于可以从许多不同因素导出的等级方案;幂律指数可以被视为依恋强度的度量。

英文摘要:

We investigate the degree distribution resulting from graph generation models based on rank-based attachment. In rank-based attachment, all vertices are ranked according to a ranking scheme. The link probability of a given vertex is proportional to its rank raised to the power -a, for some a in (0,1). Through a rigorous analysis, we show that rank-based attachment models lead to graphs with a power law degree distribution with exponent 1+1/a whenever vertices are ranked according to their degree, their age, or a randomly chosen fitness value. We also investigate the case where the ranking is based on the initial rank of each vertex; the rank of existing vertices only changes to accommodate the new vertex. Here, we obtain a sharp threshold for power law behaviour. Only if initial ranks are biased towards lower ranks, or chosen uniformly at random, we obtain a power law degree distribution with exponent 1+1/a. This indicates that the power law degree distribution often observed in nature can be explained by a rank-based attachment scheme, based on a ranking scheme that can be derived from a number of different factors; the exponent of the power law can be seen as a measure of the strength of the attachment.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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