Fluctuation in e-mail sizes weakens power-law correlations in e-mail flow

TL;DR

This paper investigates how fluctuations in email sizes affect power-law correlations in email flow, revealing that size variability weakens these correlations and that they originate from the sequence of send requests.

Contribution

It demonstrates that fluctuations in email sizes weaken power-law correlations in email flow and identifies the origin of these correlations as the sequence of send requests.

Findings

Correlation in flow is weaker than in send requests.

Fluctuations in email sizes reduce the strength of power-law correlations.

Correlation in flow stems from the sequence of send requests.

Abstract

Power-law correlations have been observed in packet flow over the Internet. The possible origin of these correlations includes demand for Internet services. We observe the demand for e-mail services in an organization, and analyze correlations in the flow and the sequence of send requests using a Detrended Fluctuation Analysis (DFA). The correlation in the flow is found to be weaker than that in the send requests. Four types of artificial flow are constructed to investigate the effects of fluctuations in e-mail sizes. As a result, we find that the correlation in the flow originates from that in the sequence of send requests. The strength of the power-law correlation decreases as a function of the ratio of the standard deviation of e-mail sizes to their average.