Borel singularities at small x

D.I.S. at small Bjorken $x$ is considered within the dipole cascade formalism. The running coupling in impact parameter space is introduced in order to parametrize effects that arise from emission of large size dipoles. This results in a new evolution equation for the dipole cascade. Strong coupling effects are analyzed after transforming the evolution equation in Borel ($b$) space. The Borel singularities of the solution are discussed first for the universal part of the dipole cascade and then for the specific process of D.I.S. at small $x$. In the latter case the leading infrared renormalon is at $b=1/\beta_0$ indicating the presence of $1/Q^2$ power corrections for the small-$x$ structure functions.Comment: 5 pages, Latex (Talk presented at DIS'97, Chicago, IL

AT&T vs Verizon: Mining Twitter for Customer Satisfaction towards North American Mobile Operators

The North American Telecommunications sector is one of the leading mobile broadband sectors worldwide, representing increasingly important revenue opportunities for mobile operators. Taking into consideration that the market is being saturated and revenue from new subscriptions is increasingly deteriorating, mobile carriers tend to focus on customer service and high levels of customer satisfaction in order to retain customers and maintain a low churn rate. In this context, it is a matter of critical importance to be able to measure the overall customer satisfaction level, by explicitly or implicitly mining the public opinion towards this end. In this paper, we argue that online social media can be exploited as a proxy to infer customer satisfaction through the utilization of automated, machine-learning based sentiment analysis techniques. Our work focuses on the two leading mobile broadband carriers located in the broader North American area, AT&T and Verizon, by analysing tweets fetched during a 15-day period within February 2013, to assess relative customer satisfaction degrees. The validity of our approach is justified through comparison against surveys conducted during 2012 from Forrester and Vocalabs in terms of customer satisfaction on the overall brand - usage experience