(Press-News.org) Males of the Japanese tree frog have learnt not to use their calls at the same time so that the females can distinguish between them. Scientists at the Polytechnic University of Catalonia have used this form of calling behaviour to create an algorithm that assigns colours to network nodes – an operation that can be applied to developing efficient wireless networks.
How can network nodes be coloured with the least possible number of colours without two consecutive nodes being the same colour? A team of researchers at the Polytechnic University of Catalonia have found a solution to this mathematical problem with the help of some rather special colleagues: Japanese tree frogs (Hyla japonica).
These male amphibians use their calls to attract the female, who can recognise where it comes from and then locate the suitor. The problem arises when two males are too close to one another and they use their call at the same time. The females become confused and are unable to determine the location of the call. Therefore, the males have had to learn how to 'desynchronise' their calls or, in other words, not call at the same time in order for a distinction to be made.
"Since there is no system of central control organising this "desynchronisation", the mechanism may be considered as an example of natural self-organisation," explains Christian Blum. With the help of his colleague Hugo Hernández, such behaviour provided inspiration for "solving the so-called 'graph colouring problem' in an even and distributed way."
A graph is a set of connected nodes. As in the case of the frog's 'desynchronised calls', operating in a 'distributed' fashion implies that there is no other way of central control that helps to solve the problem with a global vision and all the information on the situation.
In the same way, the researchers have devised a new algorithm for assigning colours to network nodes ensuring that each pair of connected nodes is not the same colour. The end goal is to generate a valid solution that uses the least amount of colours.
Application to WiFi connections
As Blum outlines, "this type of graph colouring is the formalisation of a problem that arises in many areas of the real world, such as the optimisation of modern wireless networks with no predetermined structure using techniques for reducing losses in information packages and energy efficiency improvement."
This study falls under the field of 'swarm intelligence', a branch of artificial intelligence that aims to design intelligent systems with multiple agents. This is inspired by the collective behaviour of animal societies such as ant colonies, flocks of birds, shoals of fish and frogs, as in this case.
INFORMATION:
Reference:
Hugo Hernández y Christian Blum. "Distributed Graph Coloring: An Approach Based on the Calling Behavior of Japanese Tree Frogs". Swarm Intelligence 6 (2): 117-150, 2012. Doi: 10.1007/s11721-012-0067-2.
Frog calls inspire a new algorithm for wireless networks
2012-07-18
ELSE PRESS RELEASES FROM THIS DATE:
Triggers study evaluates regular staff, ICU specialists
2012-07-18
BOSTON – A system of care focused on the detection and systematic assessment of patients with clinical instability can yield similar outcomes as rapid response teams staffed with trained intensive care specialists, a Beth Israel Deaconess Medical Center study has found.
The analysis of 177,347 patients over a 59-month period was published online in Critical Care Medicine, the journal of the Society of Critical Care Medicine. Rapid Response Teams have become an important part of hospital care in recent years, sending critical care-trained responders to the bedside of decompensating ...
Americans support local control of schools
2012-07-18
EAST LANSING, Mich. — Despite criticism that local school boards are "dinosaurs" that need to be replaced, Americans support local control of their schools, Michigan State University education scholars argue in a new paper.
The public believes that all three levels of government – local, state and federal – should be involved in education policy and that local officials should be in charge of day-to-day operations of the schools, said Rebecca Jacobsen, lead researcher on the project.
Jacobsen, assistant professor of education, and doctoral student Andrew Saultz analyzed ...
Notre Dame, MIT economists demonstrate wage impacts of large microfinance program
2012-07-18
A major argument in favor of microfinance is that the poor who live in areas without banking services will gain higher returns on investments and increase their assets when provided with credit.
But a notable new study from the Consortium on Financial Systems and Poverty presents some of the first real evidence of microfinance impacts and indicates that the true returns of expanding access to credit are much more complex. Some of the greatest benefits to alleviating poverty, the study suggests, may be in the impact the programs have on driving up wages.
The research, ...
Female money doesn't buy male happiness
2012-07-18
Macho men whose partners earn more than they do have worse romantic relationships, in part because the difference in income is a strain for them, according to a new study by Patrick Coughlin and Jay Wade from Fordham University in the US. Conversely, men who are not so traditional in their masculinity do not place as much importance on the difference in income and, as a result, appear to have better quality relationships with their female partner. The work is published online in Springer's journal Sex Roles.
The breadwinner role for men is still the accepted norm in marriage, ...
Anti-Semitic violence down 27 percent, but harassment is on the rise
2012-07-18
Though 2011 saw a significant decline in major acts of violence against the Jewish population world-wide, anti-Semitic harassment and incitement, including verbal threats, insults, and abusive behavior, have escalated, according to this year's Antisemitism Worldwide General Analysis, a publication of Tel Aviv University's Kantor Center for the Study of Contemporary European Jewry. The yearly report is based on the Center's Moshe Kantor Database for the Study of Contemporary Antisemitism and Racism.
Incidences of major violence, including the use of weapons, vandalism, ...
Punishment motivated by fairness, not revenge
2012-07-18
Researchers at UCL and Harvard have found that we punish cheats only when they end up better off than us, in a study that challenges the notion that punishment is motivated by revenge.
Published today in the journal Biology Letters, the research shows that victims of cheating compare their own payoffs with those of partners when making punishment decisions.
"Punishment is a costly behaviour which is often aimed at individuals that cheat during social interactions," said Dr Nichola Raihani (UCL Genetics, Evolution and Environment), lead author of the study. "Imagine ...
Musical glove improves sensation, mobility for people with spinal cord injury
2012-07-18
VIDEO:
Researchers at Georgia Tech and Atlanta's Shepherd Center have created a wireless, musical glove that may improve sensation and motor skills for people with spinal cord injuries. The gadget, Mobile...
Click here for more information.
Georgia Tech researchers have created a wireless, musical glove that may improve sensation and motor skills for people with paralyzing spinal cord injury (SCI).
The gadget was successfully used by individuals with limited feeling or ...
Research update: Chips with self-assembling rectangles
2012-07-18
CAMBRIDGE, Mass. -- Researchers at MIT have developed a new approach to creating the complex array of wires and connections on microchips, using a system of self-assembling polymers. The work could eventually lead to a way of making more densely packed components on memory chips and other devices.
The new method — developed by MIT visiting doctoral student Amir Tavakkoli of the National University of Singapore, along with two other graduate students and three professors in MIT's departments of Electrical Engineering and Computer Science (EECS) and Materials Science and ...
Thieving rodents: Did they save tropical trees?
2012-07-18
Big seeds produced by tropical trees such as black palms were probably once ingested and then left whole by huge mammals called gomphotheres.
Gomphotheres weighed more than a ton and dispersed the seeds over large distances.
But these Neotropical creatures disappeared more than 10,000 years ago. So why aren't large-seeded plants also extinct?
A paper published this week in the journal Proceedings of the National Academy of Sciences (PNAS) suggests that rodents may have taken over the seed-dispersal role of gomphotheres.
"The question has been: how did a tree like ...
Expert panel calls for new research approach to prevent youth violence
2012-07-18
San Diego, CA, July 17, 2012 – Most research into youth violence has sought to understand the risk factors that increase the likelihood of violence. Now, a federal panel has called for a new research approach to identify the protective factors that would reduce the likelihood that violence will happen. Grounded in the tools and insights of public health, the approach calls for studies that can guide the development of prevention strategies to reduce or eliminate risk factors, and add or enhance protective factors. The findings of the Centers for Disease Control and Prevention's ...