document

A network approach for power grid robustness against cascading failures

Wang, X. (author), Koc, Y. (author), Kooij, R.E. (author), Van Mieghem, P. (author)

Cascading failures are one of the main reasons for blackouts in electrical power grids. Stable power supply requires a robust design of the power grid topology. Currently, the impact of the grid structure on the grid robustness is mainly assessed by purely topological metrics, that fail to capture the fundamental properties of the electrical...

conference paper 2015

document

Correlation between centrality metrics and their application to the opinion model

Li, C. (author), Li, Q. (author), Van Mieghem, P.F.A. (author), Stanley, H.E. (author), Wang, H. (author)

In recent decades, a number of centrality metrics describing network properties of nodes have been proposed to rank the importance of nodes. In order to understand the correlations between centrality metrics and to approximate a high-complexity centrality metric by a strongly correlated low-complexity metric, we first study the correlation...

journal article 2015

document

Algebraic Connectivity of Interdependent Networks

Martin-Hernandez, J. (author), Wang, H. (author), Van Mieghem, P. (author), D'Agostino, G. (author)

The algebraic connectivity UN-1, i.e. the second smallest eigenvalue of the Laplacian matrix, plays a crucial role in dynamic phenomena such as diffusion processes, synchronization stability, and network robustness. In this work we study the algebraic connectivity in the general context of interdependent networks, or network-of-networks (NoN)....

journal article 2014

document

Epidemic threshold in directed networks

Li, C. (author), Wang, H. (author), Van Mieghem, P.F.A. (author)

Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ? as the...

journal article 2013

document

Epidemic threshold and topological structure of susceptible-infectious-susceptible epidemics in adaptive networks

Guo, D. (author), Trajanovski, S. (author), Van de Bovenkamp, R. (author), Wang, H. (author), Van Mieghem, P.F.A. (author)

The interplay between disease dynamics on a network and the dynamics of the structure of that network characterizes many real-world systems of contacts. A continuous-time adaptive susceptible-infectious-susceptible (ASIS) model is introduced in order to investigate this interaction, where a susceptible node avoids infections by breaking its...

journal article 2013

document

Topology of molecular interaction networks

Winterbach, W. (author), Van Mieghem, P. (author), Reinders, M. (author), Wang, H. (author), De Ridder, D. (author)

Molecular interactions are often represented as network models which have become the common language of many areas of biology. Graphs serve as convenient mathematical representations of network models and have themselves become objects of study. Their topology has been intensively researched over the last decade after evidence was found that...

journal article 2013

document

Effect of the interconnected network structure on the epidemic threshold

Wang, H. (author), Li, Q. (author), D'Agostino, G. (author), Havlin, S. (author), Stanley, H.E. (author), Van Mieghem, P. (author)

Most real-world networks are not isolated. In order to function fully, they are interconnected with other networks, and this interconnection influences their dynamic processes. For example, when the spread of a disease involves two species, the dynamics of the spread within each species (the contact network) differs from that of the spread...

journal article 2013

document

Maximum modular graphs

Trajanovski, S. (author), Wang, H. (author), Van Mieghem, P. (author)

Modularity has been explored as an important quantitative metric for community and cluster detection in networks. Finding the maximum modularity of a given graph has been proven to be NPcomplete and therefore, several heuristic algorithms have been proposed. We investigate the problem of finding the maximum modularity of classes of graphs that...

journal article 2012

document

Disruption of Functional Brain Networks in Alzheimer’s Disease: What Can We Learn from Graph Spectral Analysis of Resting-State Magnetoencephalography?

De Haan, W. (author), Van der Flier, W.M. (author), Wang, H. (author), Van Mieghem, P.F.A. (author), Scheltens, P. (author), Stam, C.J. (author)

In Alzheimer’s disease (AD), structural and functional brain network organization is disturbed. However, many of the present network analysis measures require a priori assumptions and methodological choices that influence outcomes and interpretations. Graph spectral analysis (GSA) is a more direct algebraic method that describes network...

journal article 2012

document

Do greedy assortativity optimization algorithms produce good results?

Winterbach, W. (author), De Ridder, D. (author), Wang, H.J. (author), Reinders, M. (author), Van Mieghem, P. (author)

conference paper 2012

document

The correlation of metrics in complex networks with applications in functional brain networks

Li, C. (author), Wang, H. (author), De Haan, W. (author), Stam, C.J. (author), Van Mieghem, P.F.A. (author)

An increasing number of network metrics have been applied in network analysis. If metric relations were known better, we could more effectively characterize networks by a small set of metrics to discover the association between network properties/metrics and network functioning. In this paper, we investigate the linear correlation coefficients...

journal article 2011

document

Assortativity of complementary graphs

Wang, H. (author), Winterbach, W. (author), Van Mieghem, P.F.A. (author)

journal article 2011

document

Decreasing the spectral radius of a graph by link removals

Van Mieghem, P. (author), Stevanovi?, D. (author), Kuipers, F. (author), Li, C. (author), Van de Bovenkamp, R. (author), Liu, D. (author), Wang, H. (author)

The decrease of the spectral radius, an important characterizer of network dynamics, by removing links is investigated. The minimization of the spectral radius by removing m links is shown to be an NP-complete problem, which suggests considering heuristic strategies. Several greedy strategies are compared, and several bounds on the decrease of...

journal article 2011

document

Correlating the topology of a metabolic network with its growth capacity

Winterbach, W. (author), Wang, H. (author), Reinders, M. (author), Van Mieghem, P. (author), De Ridder, D. (author)

conference paper 2010

document

Metabolic network destruction: Relating topology to robustness

Winterbach, W. (author), Wang, H. (author), Reinders, M. (author), Van Mieghem, P. (author), De Ridder, D. (author)

Biological networks exhibit intriguing topological properties such as small-worldness. In this paper, we investigate whether the topology of a metabolic network is related to its robustness. We do so by perturbing a metabolic system in silico, one reaction at a time and studying the correlations between growth, as predicted by flux balance...

conference paper 2010

document

Spectral graph analysis of modularity and assortativity

Van Mieghem, P.F.A. (author), Ge, X. (author), Schumm, P. (author), Trajanovski, S. (author), Wang, H. (author)

Expressions and bounds for Newman’s modularity are presented. These results reveal conditions for or properties of the maximum modularity of a network. The influence of the spectrum of the modularity matrix on the maximum modularity is discussed. The second part of the paper investigates how the maximum modularity, the number of clusters, and...

journal article 2010

document

Emergence of modular structure in a large-scale brain network with interactions between dynamics and connectivity

Stam, C.J. (author), Hillebrand, A. (author), Wang, H. (author), Van Mieghem, P. (author)

A network of 32 or 64 connected neural masses, each representing a large population of interacting excitatory and inhibitory neurons and generating an electroencephalography/magnetoencephalography like output signal, was used to demonstrate how an interaction between dynamics and connectivity might explain the emergence of complex network...

journal article 2010

document

Effect of tumor resection on the characteristics of functional brain networks

Wang, H. (author), Douw, L. (author), Hernández, J.M. (author), Reijneveld, J.C. (author), Stam, C.J. (author), Van Mieghem, P. (author)

Brain functioning such as cognitive performance depends on the functional interactions between brain areas, namely, the functional brain networks. The functional brain networks of a group of patients with brain tumors are measured before and after tumor resection. In this work, we perform a weighted network analysis to understand the effect of...

journal article 2010

document

Influence of assortativity and degree-preserving rewiring on the spectra of networks

Van Mieghem, P. (author), Wang, H. (author), Ge, X. (author), Tang, S. (author), Kuipers, F.A. (author)

Newman’s measure for (dis)assortativity, the linear degree correlation coefficient ?D, is reformulated in terms of the total number Nk of walks in the graph with k hops. This reformulation allows us to derive a new formula from which a degree-preserving rewiring algorithm is deduced, that, in each rewiring step, either increases or decreases ?D...

journal article 2010

document

Graphs with given diameter maximizing the algebraic connectivity

Wang, H. (author), Kooij, R.E. (author), Van Mieghem, P. (author)

We propose a class of graphs G?D(n1, n2, ..., nD+1), containing of a chain of D+1 cliques Kn1 , Kn2 , ..., KnD+1, where neighboring cliques are fully-interconnected. The class of graphs has diameter D and size N = ? 1?i?D+1ni. We prove that this class of graphs can achieve the maximal number of links, the minimum average hopcount, and more...

journal article 2010