Davide Feltoni Gurini

Signal-based user recommendation on twitter

In recent years, social networks have become one of the best ways to access information. The ease with which users connect to each other and the opportunity provided by Twitter and other social tools in order to follow person activities are increasing the use of such platforms for gathering information. The amount of available digital data is the core of the new challenges we now face. Social recommender systems can suggest both relevant content and users with common social interests. Our approach relies on a signal-based model, which explicitly includes a time dimension in the representation of the user interests. Specifically, this model takes advantage of a signal processing technique, namely, the wavelet transform, for defining an efficient pattern-based similarity function among users. Experimental comparisons with other approaches show the benefits of the proposed approach.

iSCUR: Interest and Sentiment-Based Community Detection for User Recommendation on Twitter

The increasing popularity of social networks has encouraged a large number of significant research works on community detection and user recommendation. The idea behind this work is that taking into account peculiar users’ attitudes (i.e., sentiments, opinions or ways of thinking) toward their own interests can bring benefits in performing such tasks. In this paper we describe (i) a novel method to infer sentiment-based communities without the requirement of obtaining the whole social structure, and (ii) a community-based approach to user recommendation. We take advantage of the SVO (sentiment-volume-objectivity) user profiling and the Tanimoto similarity to evaluate user similarity for each topic. Afterwards we employ a clustering algorithm based on modularity optimization to find densely connected users and the Adamic-Adar tie strength to finally suggest the most relevant users to follow. Preliminary experimental results on Twitter reveal the benefits of our approach compared to some state-of-the-art user recommendation techniques.

Temporal people-to-people recommendation on social networks with sentiment-based matrix factorization

Abstract Nowadays, the exponential advancement of social networks is creating new application areas for recommender systems (RSs). People-to-people RSs aim to exploit user’s interests for suggesting relevant people to follow. However, traditional recommenders do not consider that people may share similar interests, but might have different feelings or opinions about them. In this paper, we propose a novel recommendation engine which relies on the identification of semantic attitudes, that is, sentiment, volume, and objectivity, extracted from user-generated content. In order to do this at large-scale on traditional social networks, we devise a three-dimensional matrix factorization, one for each attitude. Potential temporal alterations of users’ attitudes are also taken into consideration in the factorization model. Extensive offline experiments on different real world datasets, reveal the benefits of the proposed approach compared with some state-of-the-art techniques.

Enhancing Social Recommendation with Sentiment Communities

Among the various recommender systems proposed in the literature, there is an increase in relevance and number of those that suggest users of possible interest to the target user. In this article, we propose a new algorithm for realizing user recommenders, named SCORES (Sentiment COmmunities REcommender System). This algorithm relies on the identification of sentiment communities in which, for each topic cited by the user, we consider not only the relative sentiment, but also the volume and the objectivity of contents generated by him. The graph related to each topic is obtained by considering the Tanimoto similarity between users. The recommendation process occurs by clustering the obtained graph to detect latent communities, and suggesting to the target user the most similar K users based on tie strength measures. A comparative analysis between SCORES and some state-of-the-art approaches shows the benefits in term of performance.

Social Recommendation with Time and Sentiment Analysis

With the increasing information overload, the identification of new users really relevant to the target user becomes more and more complicated. In this paper, we propose a social recommender based on a user model that takes into account not only her interests and preferences, but also their evolution over time and actual nature. To accurately assess the effectiveness of the proposed approach, over 1,600 users were monitored for a full year, thus collecting over 2,700,000 tweets. In this way, it was possible to deeply evaluate the proposed model, also through a comparative analysis with other state-of-the-art social recommender systems.

Dynamic Social Recommendation

This paper describes a preliminary investigation of a user modeling approach, named bag-of-signals, able to take into account how user’s interests evolve over time. The basic idea underlying such an approach is to model each potential user’s interest as a signal. In order to represent and analyze such signals, we make use of the wavelet transform, a signal processing technique that offers higher performance compared to other mathematical tools for non-stationary signals. As a case study, we employ and evaluate the proposed model in a recommender system of new users to follow in social media, focusing on Twitter. A comparative analysis on real-user data with some state-of-the-art techniques - some of which considering temporal effects as well - reveals the benefits of the proposed user modeling approach for personalized recommendations.