Maths to help out the cheese makersCheesy maths How can maths help improve the quality of cheese, and the scheduling of traffic lights to reduce traffic jams? Top mathematicians and statisticians will meet this week at the Queensland University of Technology (QUT) to discuss these and other questions. "Mathematics is often associated with theoretical pursuits," says QUT applied mathematician, Associate Professor Troy Farrell, who is involved in the Maths in Industry Study Group. "But applied maths can solve industry's everyday technical problems. "One large dairy company involved in the study group is looking to Farrell and colleagues to help them predict how cheeses change their texture and taste over time. From runny brie to nice firm cheddars, cheese maturation is affected by physical and chemical changes due to the exact mix of enzymes, chemicals and microbes in a cheese. Farrell says maths can help simulate a cheese's maturation by modelling its biochemistry using differential equations. Traffic controllers are also looking to maths to help better co-ordinate traffic signals. While they want to get as many vehicles through a busy city in as short a time as possible, they must also consider safety, pollution and driver stress. "It's about trying to control traffic lights in such a way that you can get a number of optimal outcomes," says Farrell. "But the optimal solutions can be very hard to obtain. "For example, he says, a wave of green lights reduces driver stress and associated dangerous behaviour, but it also generally involves a longer run and more pollution. Also, a wave of red lights can force drivers onto back streets that weren't designed to carry much traffic. Farrell says current traffic network models do not encompass these trade-offs and rely on traffic experts to judge how to manually adjust the system to balance between competing objectives. He says maths can be used to improve models so these decisions can be automated. The mathematical model would also be "adaptive" to allow for changing conditions over time, says Farrell. "As more cars come onto the road of course the solutions you obtained yesterday may not apply and new ones need to be developed," he says. Master cheese-makers may pride themselves on the role of their expert knowledge which is often passed down the generations, but Farrell says maths can give experts support. "You will always need some input from human beings. This is definitely not about doing away with the expert knowledge factor," he says. "It's about enhancing expert knowledge." Farrell says it is useful to develop models based on expert understanding, to see how well we understand what is going on - or not. "Sometimes we may think we understand a process but really we don't," he says. The meeting this week will also explore how maths can improve our understanding of coral reefs, as well as the spread of AIDS and other sexually transmissible diseases.