Banca de DEFESA: RICARDO LOPES DE ANDRADE

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RICARDO LOPES DE ANDRADE
DATE: 21/12/2021
TIME: 09:00
LOCAL: Online
TITLE:

SOCIAL NETWORK ANALYSIS: METRICS AND APPLICATIONS

KEY WORDS:

Trade networks. Criminal networks. Coauthorship networks. p-means centrality.
Energy disruptive centrality. Generalized EI index.

PAGES: 109
BIG AREA: Engenharias
AREA: Engenharia de Produção
SUMMARY:

Many social interactions can be modeled by networks, in which social actors are
represented by nodes and their relationships by edges. Researchers over the years have used
social network analysis (SNA) to study the topological structure of the network and understand
relational patterns. There are several centrality measures in the literature, with different criteria
that define which nodes are more central. In addition, several studies seek to understand how
network structures are formed. More recently, scholars have included in the SNA the actors’
attributes in the search for a better understanding, given that these attributes can influence the
way relationships occur and, consequently, affect the network structure. This PhD Dissertation,
by exploring gaps in the literature, aims to contribute to the advancement of this field, proposing
new metrics: (i) considering the geodesic paths among pairs of nodes, it is proposed a generalized
measure, called p-means centrality, depending on the value given to the parameter p, several
measures of centrality are obtained; (ii) two centrality measures, based on the law of gravity
are proposed, in which the strength of the nodes’ attributes is combined with the strength of
the relationships between them, the main measure is called energy disruptive; (iii) to explore
the network formation, two measures are proposed that generalize the EI Index, a measure of
homophily. One can be applied in case of disjoint and non-disjoint groups and the other, more
complete, also explores the case of fuzzy groups. Several networks were considered to test the
use of these metrics: (i) the p-means centrality was applied in a co-authorship network and in
a transport network; (ii) disruptive energy centrality was applied in two crime networks; (iii)
the two measures that generalize the EI index were applied in a co-authorship network and in
an international trade network. Among the best results obtained it can be highlighted: (i) the
p-means centrality have shown that the most central nodes, defined by negative values of p, are
closer to the nodes with the greatest spreading capacity, defined by the SIR model; (ii) disruptive
energy centrality, when used as a target method, was the most efficient strategy, providing greater
network damage than other centrality measures analyzed; (iii) the EI index was able to explore
the formation of networks in cases of non-disjoint groups and also fuzzy groups, proving the
generalization of the measures. Therefore, the metrics proposed in this work enhance the SNA
by unifying existing centrality metrics, incorporating nodes’ attributes in SNA metrics, and
extending the scope of homophily studies to more general types of groups.

BANKING MEMBERS:
Externo à Instituição - JOSE ANTONIO FERNANDES DE MACEDO
Interno - 1171015 - FRANCISCO DE SOUSA RAMOS
Externo à Instituição - JESÚS PASCUAL MENA-CHALCO
Presidente - 2308467 - LEANDRO CHAVES REGO
Interna - 1809373 - MAISA MENDONCA SILVA