scholarly journals Usando análises sociais na identificação de nós relevantes em um cenário multi-redes: Operação Licitante Fantasma, um estudo de caso

2020 ◽  
Author(s):  
Bruno Figueiredo ◽  
Fabiola Nakamura ◽  
Gardenya Felix ◽  
Eduardo Nakamura

Este artigo propõe o modelo NDNS (Nodes Detection using Network Science) que, usando redes complexas, busca encontrar os nós mais relevantes, em um cenário multi-redes, de forma mais eficiente do que medidas de centralidade estabelecidas. O artigo utiliza, como estudo de caso, uma investigação de corrupção em licitações públicas no Brasil – Operação de Licitante Fantasma. Considerando um período de quatro anos de investigações, o NDNS, quando comparado a quatro medidas de centralidade (betweenness, eigenvector, weighted degree, page rank e sua média geométrica normalizada), alcançou uma precisão de 93% e uma revocação de 94% na detecção de valores fraudulentos contra 38% e 51%, respectivamente, das segundas medidas mais bem posicionadas.

2012 ◽  
Vol 37 (4) ◽  
pp. 293-303
Author(s):  
Stanisław Saganowski ◽  
Piotr Bródka ◽  
Przemysław Kazienko

AbstractOne of the most interesting topics in social network science are social groups, i.e. their extraction, dynamics and evolution. One year ago the method for group evolution discovery (GED) was introduced. The GED method during extraction process takes into account both the group members quality and quantity. The quality is reflected by user importance measure. In this paper the influence of different user importance measures on the results of the GED method is examined and presented. The results indicate that using global measures like social position (page rank) allows to achieve more precise results than using local measures like degree centrality or no measure at all.


2012 ◽  
Author(s):  
Daniel Evans ◽  
Evan Szablowski ◽  
Zachary Langhans

Author(s):  
Stefan Thurner ◽  
Rudolf Hanel ◽  
Peter Klimekl

Understanding the interactions between the components of a system is key to understanding it. In complex systems, interactions are usually not uniform, not isotropic and not homogeneous: each interaction can be specific between elements.Networks are a tool for keeping track of who is interacting with whom, at what strength, when, and in what way. Networks are essential for understanding of the co-evolution and phase diagrams of complex systems. Here we provide a self-contained introduction to the field of network science. We introduce ways of representing and handle networks mathematically and introduce the basic vocabulary and definitions. The notions of random- and complex networks are reviewed as well as the notions of small world networks, simple preferentially grown networks, community detection, and generalized multilayer networks.


Author(s):  
Zachary P. Neal

The first law of geography holds that everything is related to everything else, but near things are more related than distant things, where distance refers to topographical space. If a first law of network science exists, it would similarly hold that everything is related to everything else, but near things are more related than distant things, but where distance refers to topological space. Frequently these two laws collide, together holding that everything is related to everything else, but topographically and topologically near things are more related than topographically and topologically distant things. The focus of the spatial study of social networks lies in exploring a series of questions embedded in this combined law of geography and networks. This chapter explores the questions that have been asked and the answers that have been offered at the intersection of geography and networks.


2021 ◽  
pp. 004728752110247
Author(s):  
Sangwon Park ◽  
Ren Ridge Zhong

Urban tourism is considered a complex system. Tourists who visit cities have diverse purposes, leading to multifaceted travel behaviors. Understanding travel movement patterns is crucial in developing sustainable planning for urban tourism. Built on network science, this article discusses 12 key topologies of travel patterns/flow occurring in a city network by applying network motif analytics. The 12 significant types of travel mobility can account for approximately 50% of the total movement patterns. In addition, this study presents variations in travel movement patterns depending on not only different lengths of stay in topological structures of travel mobility, but also relative proportions of each type. As a result, this article suggests an interdisciplinary approach that adopts the network science method to better understand city travel behaviors. Important methodological and practical implications that could be useful for city destination planners are suggested.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1045
Author(s):  
Marta B. Lopes ◽  
Eduarda P. Martins ◽  
Susana Vinga ◽  
Bruno M. Costa

Network science has long been recognized as a well-established discipline across many biological domains. In the particular case of cancer genomics, network discovery is challenged by the multitude of available high-dimensional heterogeneous views of data. Glioblastoma (GBM) is an example of such a complex and heterogeneous disease that can be tackled by network science. Identifying the architecture of molecular GBM networks is essential to understanding the information flow and better informing drug development and pre-clinical studies. Here, we review network-based strategies that have been used in the study of GBM, along with the available software implementations for reproducibility and further testing on newly coming datasets. Promising results have been obtained from both bulk and single-cell GBM data, placing network discovery at the forefront of developing a molecularly-informed-based personalized medicine.


2020 ◽  
Vol 148 ◽  
Author(s):  
N. Gürsakal ◽  
B. Batmaz ◽  
G. Aktuna

Abstract When we consider a probability distribution about how many COVID-19-infected people will transmit the disease, two points become important. First, there could be super-spreaders in these distributions/networks and second, the Pareto principle could be valid in these distributions/networks regarding estimation that 20% of cases were responsible for 80% of local transmission. When we accept that these two points are valid, the distribution of transmission becomes a discrete Pareto distribution, which is a kind of power law. Having such a transmission distribution, then we can simulate COVID-19 networks and find super-spreaders using the centricity measurements in these networks. In this research, in the first we transformed a transmission distribution of statistics and epidemiology into a transmission network of network science and second we try to determine who the super-spreaders are by using this network and eigenvalue centrality measure. We underline that determination of transmission probability distribution is a very important point in the analysis of the epidemic and determining the precautions to be taken.


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