Search results for "Complex network"

Google matrix analysis of worldwide football mercato

2018

[EN] The worldwide football transfer market is analyzed as a directed complex network: the football clubs are the network nodes and the directed edges are weighted by the total amount of money transferred from a club to another. The Google matrix description allows to treat every club independently of their richness and allows to measure for a given club the efficiency of player sales and player acquisitions. The PageRank algorithm, developed initially for the World Wide Web, naturally characterizes the ability of a club to import players. The CheiRank algorithm, also developed to analyze large scale directed complex networks, characterizes the ability of a club to export players. The analy…

Wikipedia network analysis of cancer interactions and world influence

2019

AbstractWe apply the Google matrix algorithms for analysis of interactions and influence of 37 cancer types, 203 cancer drugs and 195 world countries using the network of 5 416 537 English Wikipedia articles with all their directed hyperlinks. The PageRank algorithm provides the importance order of cancers which has 60% and 70% overlaps with the top 10 cancers extracted from World Health Organization GLOBOCAN 2018 and Global Burden of Diseases Study 2017, respectively. The recently developed reduced Google matrix algorithm gives networks of interactions between cancers, drugs and countries taking into account all direct and indirect links between these selected 435 entities. These reduced n…

Unprecedented layered coordination polymers of dithiolene group 10 metals: Magnetic and electrical properties

2016

One-pot reactions between Ni(ii), Pd(ii) or Pt(ii) salts and 3,6-dichloro-1,2-benzenedithiol (HSC6H2Cl2SH) in KOH medium under argon lead to a series of bis-dithiolene coordination polymers. X-ray analysis shows the presence of a common square planar complex [M(SC6H2Cl2S)2]2- linked to potassium cations forming either a two-dimensional coordination polymer network for {[K2(μ-H2O)2(μ-thf)(thf)2][M(SC6H2Cl2S)2]}n [M = Ni (1) and Pd (2)] or a one-dimensional coordination polymer for {[K2(μ-H2O)2(thf)6][Pt(SC6H2Cl2S)2]}n (3). In 3 the coordination environment of the potassium ions may slightly change leading to the two-dimensional coordination polymer {[K2(μ-H2O)(μ-thf)2][Pt(SC6H2Cl2S)2]}n (4) …

Path‐dependencies, constrained transformations and dynamic agency

2013

PurposeThe purpose of this paper is to discuss the compatibility of actor network theory (ANT) and new institutional sociology (NIS) in analysing a case study of accounting change.Design/methodology/approachThis is an interpretive case study.FindingsThe Finnish case city experienced several path‐dependent changes concerning performance measurement (PM), financial reporting and the adoption of enterprise resource planning system (ERP). New tools such as the ERP have a potential to transform the actors and to change the agency of the actors. Furthermore, the concepts drawing on both ANT and NIS can together enrich analyses of accounting changes.Research limitations/implicationsThe case analys…

Dynamics of fintech terms in news and blogs and specialization of companies of the fintech industry

2020

We perform a large scale analysis of a list of fintech terms in (i) news and blogs in English language and (ii) professional descriptions of companies operating in many countries. The occurrence and co-occurrence of fintech terms and locutions shows a progressive evolution of the list of fintech terms in a compact and coherent set of terms used worldwide to describe fintech business activities. By using methods of complex networks that are specifically designed to deal with heterogeneous systems, our analysis of a large set of professional descriptions of companies shows that companies having fintech terms in their description present over-expressions of specific attributes of country, muni…

A tool for filtering information in complex systems

2005

We introduce a technique to filter out complex data-sets by extracting a subgraph of representative links. Such a filtering can be tuned up to any desired level by controlling the genus of the resulting graph. We show that this technique is especially suitable for correlation based graphs giving filtered graphs which preserve the hierarchical organization of the minimum spanning tree but containing a larger amount of information in their internal structure. In particular in the case of planar filtered graphs (genus equal to 0) triangular loops and 4 element cliques are formed. The application of this filtering procedure to 100 stocks in the USA equity markets shows that such loops and cliqu…

Backbone of credit relationships in the Japanese credit market

2016

We detect the backbone of the weighted bipartite network of the Japanese credit market relationships. The backbone is detected by adapting a general method used in the investigation of weighted networks. With this approach we detect a backbone that is statistically validated against a null hypothesis of uniform diversification of loans for banks and firms. Our investigation is done year by year and it covers more than thirty years during the period from 1980 to 2011. We relate some of our findings with economic events that have characterized the Japanese credit market during the last years. The study of the time evolution of the backbone allows us to detect changes occurred in network size,…

Spanning Trees and bootstrap reliability estimation in correlation based networks

2007

We introduce a new technique to associate a spanning tree to the average linkage cluster analysis. We term this tree as the Average Linkage Minimum Spanning Tree. We also introduce a technique to associate a value of reliability to links of correlation based graphs by using bootstrap replicas of data. Both techniques are applied to the portfolio of the 300 most capitalized stocks traded at New York Stock Exchange during the time period 2001-2003. We show that the Average Linkage Minimum Spanning Tree recognizes economic sectors and sub-sectors as communities in the network slightly better than the Minimum Spanning Tree does. We also show that the average reliability of links in the Minimum …

Texture Discrimination Using Hierarchical Complex Networks

2008

Texture analysis represents one of the main areas in image processing and computer vision. The current article describes how complex networks have been used in order to represent and characterized textures. More speci?cally, networks are derived from the texture images by expressing pixels as network nodes and similarities between pixels as network edges. Then, measurements such as the node degree, strengths and clustering coe?cient are used in order to quantify properties of the connectivity and topology of the analyzed networks. Because such properties are directly related to the structure of the respective texture images, they can be used as features for characterizing and classifying te…

2019

Abstract Peer review is not only a quality screening mechanism for scholarly journals. It also connects authors and referees either directly or indirectly. This means that their positions in the network structure of the community could influence the process, while peer review could in turn influence subsequent networking and collaboration. This paper aims to map these complex network implications by looking at 2232 author/referee couples in an interdisciplinary journal that uses double blind peer review. By reconstructing temporal co-authorship networks, we found that referees tended to recommend more positively submissions by authors who were within three steps in their collaboration netwo…