Important and complex systems may be more controllable than they appear

Mar 20, 2014
To control complex systems, Professors Ruths and Ruths identify levers - parts of the system (e.g., proteins in cells and companies in markets) - that can be used to influence the rest of the system. Control profiles, imaged here as triangular heatmaps, depict the breakdown of these leverage points based on three elements of network architecture. Despite the diversity of control profile signatures arising from real world systems, clusters form around these same three components and provide insight into the organization of these systems.Credit: Justin and Derek Ruths

We don't often think of them in these terms, but our brains, global financial markets and groups of friends are all examples of different kinds of complex networks or systems. And unlike the kind of system that exists in your car that has been intentionally engineered for humans to use, these systems are convoluted and not obvious how to control. Economic collapse, disease, and miserable dinner parties may result from a breakdown in such systems, which is why researchers have recently being putting so much energy into trying to discover how best to control these large and important systems.

But now two brothers, Profs. Justin and Derek Ruths, from Singapore University of Technology and Design and McGill University respectively, have suggested, in an article published in Science, that all complex systems, whether they are found in the body, in international finance, or in social situations, actually fall into just three basic categories, in terms of how they can be controlled.

They reached this conclusion by surveying the inputs and outputs and the critical control points in a wide range of systems that appear to function in completely different ways. (The critical control points are the parts of a system that you have to control in order to make it do whatever you want - not dissimilar to the strings you use to control a puppet).

"When controlling a cell in the body, for example, these control points might correspond to proteins that we can regulate using specific drugs," said Justin Ruths. "But in the case of a national or international economic system, the critical control points could be certain companies whose financial activity needs to be directly regulated."

One grouping, for example, put organizational hierarchies, gene regulation, and human purchasing behaviour together, in part because in each, it is hard to control individual parts of the system in isolation. Another grouping includes social networks such as groups of friends (whether virtual or real), and neural networks (in the brain), where the systems allow for relatively independent behaviour. The final group includes things like food systems, electrical circuits and the internet, all of which function basically as closed systems where resources circulate internally.

This video is not supported by your browser at this time.
Control Profiles: Control Profiles of complex networks indicate that different types of systems share common underlying features, which allow them to be controlled in similar ways. These connections across function and discipline are captured by the grouping of systems into three distinct classifications. Credit: Justin and Derek Ruths

Referring to these groupings, Derek Ruths commented, "While our framework does provide insights into the nature of control in these systems, we're also intrigued by what these groupings tell us about how very different parts of the world share deep and fundamental attributes in common – which may help unify our understanding of complexity and of control."

"What we really want people to take away from the research at this point is that we can control these complex and important systems in the same way that we can control a car," says Justin Ruths. "And that our work is giving us insight into which parts of the system we need to control and why. Ultimately, at this point we have developed some new theory that helps to advance the field in important ways, but it may still be another five to ten years before we see how this will play out in concrete terms."

Explore further: Google unveils 'stick' computer with Asus

More information: 'Control Profiles of Complex Networks' in Science by Justin and Derek Ruths: www.sciencemag.org/lookup/doi/… 1126/science.1242063

Related Stories

Applications of optical fibre for sensors

2 hours ago

Mikel Bravo-Acha's PhD thesis has focused on the applications of optical fibre as a sensor. In the course of his research, conducted at the NUP/UPNA-Public University of Navarre, he monitored a sensor fitted to optical fibre ...

Beijing behind Internet security violation: group

Mar 25, 2015

China's cyberspace administration is "complicit" in attacks on major Internet companies including Google, an anti-censorship group said Wednesday, calling on firms worldwide to strengthen their defences.

Recommended for you

Vibration pen is designed for people with Parkinson's

6 minutes ago

A woman appears in a video about a very special pen, the ARC, specifically designed for people with Parkinson's living with micrographia. Diagnosed with Parkinson's in 2013, the woman says that, over time, ...

Google launches cheapest Chromebooks yet

Mar 31, 2015

Google is unveiling its cheapest Chromebook laptops yet, two versions priced at $149 aimed at undercutting Microsoft's Windows franchise and gaining an even stronger hold in school and overseas markets.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Whydening Gyre
not rated yet Mar 20, 2014
Ahhh... Fractality makes it to mainstream...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.