Archives for 


A Mixed Graph Framework to Evaluate the Complementarity of Communication Tools

Authors: Leonardo Carvalho, Eduardo Bezerra, Gustavo Guedes, Laura Assis, Leonardo Lima, Rafael Barbastefano, Artur Ziviani, Fabio Porto, Eduardo Ogasawara

Federal Center for Technological Education of Rio de Janeiro (CEFET/RJ)

National Laboratory for Scientific Computing (LNCC)

Abstract: Due to the constant innovations in communications tools, several organizations are constantly evaluating the adoption of new communication tools (NCT) with respect to current ones. Especially, many organizations are interested in checking if NCT is really bringing benefits in their production process. We can state an important problem that tackles this interest as for how to identify when NCT is providing a significantly different complementary communication flow with respect to the current communication tools (CCT). This paper presents the Mixed Graph Framework (MGF) to address the problem of measuring the complementarity of a NCT in the scenario where some CCT is already established. We evaluated MGF using synthetic data that represents an enterprise social network (ESN) in the context of well-established e-mail communication tool. Our experiments observed that the MGF was able to identify whether a NCT produces significant changes in the overall communications according to some centrality measures.

Acknowledgments: The authors thank CNPq, CAPES, and FAPERJ for partially sponsoring this research.

Experimental Evaluation:

The evaluation of the proposed MGF in measuring if a NCT brings complementarity to a CCT for scenarios of Small Medium Enterprises (SME). We used synthetic data to simulate both CCT and NCT usage to explore the MGF under different group configurations and enterprise scales. Both MGF and experimental evaluation is made available at

Preprint at

Evaluating Temporal Aggregation for Predicting the Sea Surface Temperature of the Atlantic Ocean

Authors: Rebecca Salles, Patricia Mattos, Ana-Maria Dubois Iorgulescu, Eduardo Bezerra, Leonardo Lima, Eduardo Ogasawara Federal Center for Technological Education of Rio de Janeiro (CEFET/RJ) Abstract: Extreme environmental events such as droughts affect millions of people all around the world. Although it is not possible to prevent this type of event, its prediction under different time […]
Continue reading →

An Analysis of Brazilian Flight Delays Based on Frequent Patterns

Authors: Alice Sternberg, Diego Carvalho, Leonardo Murta, Jorge Soares and Eduardo Ogasawara Federal Center for Technological Education of Rio de Janeiro (CEFET/RJ) Abstract: In this paper, we applied data indexing techniques combined with association rules to unveil hidden patterns of flight delays. Considering Brazilian flight data and guided by six research questions related to causes, moments, […]
Continue reading →