Tag Archives: complex networks

Control of Complex Networks

Control of the eukaryotic cell cycle of budding yeast Saccharomyces cerevisiae (from Nature.com, click for details)

Network science has allowed us to understand the organization of complex systems across disciplines. However, there is a need to understand how to control them; for example, to identify strategies to revert a diseased cell to a healthy state in cancer treatment. Recent work in the field—based on linear control theory—suggests that the controllability of complex systems can be predicted solely from the graph of interactions between variables, without considering their dynamics. Such graph-based approaches have been used, for instance, to suggest that biological systems are harder to control and have appreciably different control profiles than social or technological systems. The methodology has also been increasingly used in many applications from financial to biochemical networks.

In work published today in Nature Scientific Reports, CNetS graduate student Alexander Gates and Professor Luis Rocha demonstrate that such graph-based methods fail to characterize controllability when dynamics are introduced. The study computed the control profiles of large ensembles of multivariate systems as well as existing Systems Biology models of biochemical regulation in various organisms.

Continue reading Control of Complex Networks

CNetS team studies generalized modularity in complex networks & Systems

mediumModularity in complex systems can be observed in networks and across dynamical states, time scales, and in response to different kinds of perturbations. In a paper published in Physical Review E (Rapid Communication), Kolchinsky, Gates & Rocha propose a principled alternative to detecting communities in static and dynamical networks. The method demonstrates that standard modularity measures on static networks can be seen as a special case of measuring the spread of perturbations in dynamical systems. Thus, the new method offers a powerful tool for exploring the modular organization of complex dynamical systems.

CNetS team winner in LinkedIn Economic Graph Challenge

The CNetS team
The CNetS team

LinkedIn announced that YY Ahn and his team of Ph.D. students from the Center for Complex Networks and Systems Research, including Yizhi Jing, Adazeh Nematzadeh, Jaehyuk Park, and Ian Wood, is one of the 11 winners of the LinkedIn Economic Graph Challenge.

Their project, “Forecasting large-scale industrial evolution,” aims to understand the macro-evolution of industries to track businesses and emerging skills. This data would be used to forecast economic trends and guide professionals toward promising career paths.

“This is a fascinating opportunity to study the network of industries and people with unprecedented details and size. All of us are very excited to collaborate with LinkedIn and our LinkedIn mentor, Mike Conover, who is a recent Informatics PhD alumnus, on this topic,” said Ahn. Read more…

New CASCI papers on Complex Networks

Network Science Journal
Network Science

Read new papers from CASCI on developing the mathematical toolbox available to deal with computing distances on weighted graphs, applying distance closures for computational fact checking, and computing multi-scale integration in brain networks:

T. Simas and L.M. Rocha [2015].”Distance Closures on Complex Networks”. Network Science, doi:10.1017/nws.2015.11.

G.L. Ciampaglia, P. Shiralkar, L.M. Rocha, J. Bollen, F. Menczer, A. Flammini [2015]. “Computational fact checking from knowledge networks.” PLoS One. In Press. arXiv:1501.03471.

A. Kolchinsky, M. P. Van Den Heuvel, A. Griffa, P. Hagmann, L.M. Rocha, O. Sporns, J. Goni [2014]. “Multi-scale Integration and Predictability in Resting State Brain Activity”. Frontiers in Neuroinformatics, 8:66. doi: 10.3389/fninf.2014.00066.

Indiana University Network Science Institute

iuni
IUNI announcement in Science magazine

The new Indiana University Network Science Institute (IUNI) unites 100+ researchers at IU — building on their world-renowned multidisciplinary expertise toward further scientific understanding of the complex networked systems of our world. Through pioneering new approaches in mapping, representing, visualizing, modeling, and analyzing diverse complex networks across levels and disciplines, IUNI will lead the way. We keep track of the big picture — ever-changing and interconnected. We’re laying the groundwork for innovative research and discovery in the area of network science.

Radicchi wins first CSS junior scientific award

Filippo Radicchi at ECCS 2014
Filippo Radicchi at ECCS 2014

Congratulations to Filippo Radicchi for winning the First Junior Scientific Award from the Complex Systems Society (CCS), which unveiled the winners of the first CSS scientific awards in a packed plenary session at ECCS’14 in Lucca, Italy. CSS also honored Prof. Eugene Stanley with the Senior Scientific Award, and Dr. Giovanna Miritello with a second Junior Scientific Award. Quoting the nomination:

Filippo Radicchi is among the best young researchers in complex systems and networks, with contributions that span from theoretical studies of structural and dynamical properties of networks to analyses of large-scale empirical data about human behaviour and performance.

We could not agree more.

Social Dynamics of Science

doi:10.1038/srep01069Read our latest paper titled Social Dynamics of Science in Nature Scientific Reports. Authors Xiaoling Sun, Jasleen Kaur, Staša Milojević, Alessandro Flammini & Filippo Menczer ask, How do scientific disciplines emerge? No quantitative model to date allows us to validate competing theories on the different roles of endogenous processes, such as social collaborations, and exogenous events, such as scientific discoveries. Here we propose an agent-based model in which the evolution of disciplines is guided mainly by social interactions among agents representing scientists. Disciplines emerge from splitting and merging of social communities in a collaboration network. We find that this social model can account for a number of stylized facts about the relationships between disciplines, scholars, and publications. These results provide strong quantitative support for the key role of social interactions in shaping the dynamics of science. While several “science of science” theories exist, this is the first account for the emergence of disciplines that is validated on the basis of empirical data.

Welcome and congratulations to YY Ahn!

YY AhnWe are excited to welcome a new faculty member, Yong-Yeol “YY” Ahn, to our center. Prior to joining IU, YY was a postdoctoral researcher at the Center for Complex Network Research at Northeastern University and a visiting researcher at the Center for Cancer Systems Biology at Dana-Farber Cancer Institute, working with Albert-László Barabási. YY has a PhD in Physics from KAIST in Korea. His work explores  the structure and dynamics of complex systems, spanning from molecules to society.

YY has been selected by the Association of Korean Physicists in America as one of the two winners of the annual Outstanding Young Researcher Award. And to top it off, his paper on Flavor network and the principles of food pairing was the most downloaded of all Nature.com in December 2011. Congratulations!