Australian Math Society Web Site

MISG 1996

Kerry Landman and Tim Thwaites

Introduction

The MISG (Mathematics-in-Industry Study Group) brings together mathematicians from universities and government laboratories to work on practical problems brought from industry. Besides generating solutions to specific problems, the MISG serves to showcase to industry the problem-solving power of mathematics, and exposes academic mathematicians and students to challenges facing industry as well as providing new ideas and fresh areas of research. Since March 1993 the Department of Mathematics at the University of Melbourne has directed and sponsored the MISG.

The climax of the MISG's activities is an annual five-day workshop. On the Monday the industry representatives set the workshop in motion when they outline their projects. For the next three days the mathematicians work collaboratively in lively brainstorming sessions with the industrial presenters and on the final day the mathematicians summarise their progress. Despite the short time frame a great deal can be achieved, with participants working on the project or projects that take their fancy. MISG Summaries containing short equation-free reports, as well as detailed technical reports, are published.

MISG 1996

MISG 1996 was held at the University of Melbourne from 29 January to 2 February 1996. A record number of delegates, over 175, attended the meeting: this number included over 50 postgraduate students and ten overseas delegates. The following eight topics were considered at the meeting.

Project 1. Warehouse optimisation (Australian Paper):
Mills which produce a range of papers of different specifications work most efficiently in a cycle where each paper type is made every two to four weeks. But their customers, such as the manufacturers of cardboard boxes, must be able to respond rapidly to commercial demand. This means they may need to switch between papers of different specifications from one day to the next as a vegetable crop ripens, for instance, or a line of packaging is redesigned. To overcome this mismatch in timing, a buffer of reels of paper of different types needs to be held in a store which is accessible to customers. While the customers maintain their own warehouses for this purpose, these typically cannot hold enough paper of enough different types to cope with all their needs. So mills must use intermediate stores which increases costs, handling and the risk of damage to paper reels. Australian Paper asked the MISG to devise a model which would allow its paper mills to maximise direct delivery to customer stores and minimise reel handling. The company also expected the solution to involve recommendations as to the best way to lay out the warehouses. In response, the MISG team was able to provide several different approaches from which the company might be able to develop models for delivery schedules. It was also able to recommend changes in the traditional configuration of storage areas to increase their efficiency and versatility.

Project 2. Methodologies for decision-making in tree breeding programs (Various industries involved in the CRC for Temperate Hardwood Forestry):
Tree breeders have several key decisions to make selecting which trees are to be used in the breeding program and how often to breed them, then selecting the trees to mate with each other and finally selecting which resultant offspring to plant out. The MISG team was able to develop models which looked at tree breeding from three different aspects. The first model applied to selection of trees for breeding. It maximised the breeding value of individual trees while minimising inbreeding. Algorithms already exist to turn this model into a useful computer program. The second model maximised entropy, a measure of genetic diversity. While this model needed further work, it looked promising. The third model took a population of desired genetic diversity and gave a measure of the breeding value of the best progeny. After further development, it should be possible to use this third model to predict genetic improvement from generation to generation.

Project 3. Homogenisation of photographic dispersions (Kodak):
Fine droplets of photographic chemicals are formed by forcing an emulsion of coarse droplets through a steel tube with one or more abrupt constrictions, each consisting of a small hole in a barrier or plate across the cylinder. Kodak approached the MISG to examine the optimum geometry for this device, which is known as an orifice disperser, the best size and shape for the hole or holes, and the number and spacing of plates. The MISG team came up with several ideas for changing the geometry of the plate but did not have data available to test their impact. It became clear from the team's work that, in general, the configuration used in the disperser was relatively efficient and that there was only a marginal gain in using more than one plate.

Project 4. Cooling of jarred cheese spreads (Kraft):
Cheese spread is a remarkably good insulator. It takes a long time to cool after it is cooked. But if the temperature of the spread is not brought down from about 85 degrees C to less than 25 degrees C as soon as possible, it tends to spoil. In order to achieve the correct cooling, Kraft Foods passes filled jars of cheese spread through a cooler which lowers the temperature to an acceptable level within about 50 minutes. Having recently built a new production line for cheese spreads at its factory complex in Strathmerton, northern Victoria, Kraft Foods asked the MISG to model and examine the operation of the cooler. The MISG team was able to develop applicable heat transfer models (which gave answers closely matched to Kraft's data) and recommended changes to the cooling system including installation of a larger heat exchanger to chill water to be used. The team also gave a nifty explanation to why the cheese spread can boil near the centre of the jar and how to eliminate it.

Project 5. Modelling optical fibre cable (MM Cables):
MM Cables, a major manufacturer and supplier of cable to the telecommunications industry in Australia and overseas, asked MISG to model the manufacture of optical fibre cable to help with setting and controlling equipment. The MISG team derived three models of the trajectory of the loose tubes, one estimating the position of the tube with respect to the backbone and the other two incorporating the changes in rotational speed of the machinery used to wind the cable. These latter two models could be improved if more were known about the process of winding. The team recommended extracting the necessary data from slow-motion video. As cables are subject to tension when being laid, and may have to cope with ambient temperatures which can vary between 70 degrees C and 9640 degrees C, the company also asked the MISG team to investigate conditions under which the fibres would remain strain free should the cable expand or contract. The team developed a relatively simple model to cover the case of expansion, but found that contraction could lead to buckling of the fibres, making it difficult to model. An experimental program will be established at the University of Queensland.

Project 6. Wet gum labelling of wine bottle (Southcorp Wines):
Bubbles are endemic to the labels of glass drink bottles. They are a matter of little concern to manufacturers of soft drinks and beer. But to Southcorp Wines, a producer of premium wines under brand names such as Penfolds and Lindemans, bubbles in the label can ruin the impression of quality. The problem is enigmatic. It occurs in about one batch in 20, and appears to be dependent on moisture. Bubbles which form under humid conditions disappear when conditions dry out. The winemakers, label-printers and glue manufacturer were looking for an indication of how sensitive the process was to bottle defects, the relative humidity and water absorption of paper, and the strength of the glue. The MISG team looked at the problem from a variety of angles and made several suggestions. First, the team recommended better temperature and humidity control to ensure better glue bonding. Second, the elastic nature of the glue could cause tension as the paper expanded upon absorbing water. So the team advised breaking up the continuity of glue to help make it more flexible. Third, in order to set, the glue loses water. The team calculated that the label does not absorb enough water to assist this process much. Perhaps the bubble problem could be alleviated if the paper absorbed no water at all, eg by using paper varnished on both sides. Fourth, the length of time spent pressing the label onto the bottle depends on the speed of the production line. To ensure the highly viscous glue spreads so that labels are stuck firmly, this time must be greater than the calculated minimum. To achieve this minimum time, the team estimated the maximum speed of the production line.

Insert photograph here.

Mr Barry Grennan, Mr Bruce McComb, Dr Jim Banhan (Australian Paper) and Professor Alan Gilbert, Dr Kerry Landman at opening of MISG.

Project 7. Modelling the cooking process of a single cereal grain (Uncle Tobys):
Cereal grains are seeds packed with starch granules. Heating them in a moist environment causes the granules initially to swell and then to burst releasing a viscous starch paste. This process is known as gelatinisation. The starch paste is what gives the breakfast cereal its texture. If kept at the cooking temperature, however, the paste begins to degrade almost immediately. So, for optimum taste, the grains should be cooked to the point of gelatinisation and no further. Uncle Tobys Company asked MISG to determine how to cook grains for the best texture and taste. The company was looking to speed up the cooking process and ensure its grains were evenly cooked. More specifically it wanted the MISG to establish two models of a single grain: one predicting moisture content, and the other predicting internal temperature in terms of grain properties and size, process temperature and pressure, and time. The MISG team set up the requested models for several different grain shapes, and gradually refined them. The team rapidly established that heating a grain to cooking temperature took about 10 seconds, while wetting it took about 30 minutes. So, by presoaking the grain before heating, it was possible to cut current cooking times of between 60 and 90 minutes to less than half. And the grain would be cooked more evenly.

Project 8. Blending methodologies in talc operations (Western Mining Corp.):
Magnesium silicate rock which is crushed into talc is graded according to brightness (whiteness) and content of impurities, the most significant of which is calcium oxide. The two highest grades, which are bright and low in calcium oxide, are in demand and command the best price. Western Mining manually sorts talc rock into six different grades for shipping. In the past, if there were not enough of a specific grade in stock to fill a particular order, the company would mine more. It now wants to take a more sophisticated approach. The company recognises that its grading categories are coarse and that if it could meet the specifications of orders more precisely, it could use its materials more efficiently. Often, for instance, the material supplied to meet an order betters the specification requested. In this case, high grade material could be blended with a certain amount of cheaper lower grade rock and still meet the order requirement. Not only would this extend the high quality resource, it would also ensure better utilisation of lower grade material. With this in mind, Western Mining asked MISG to build a mathematical model which would allow the company to blend talc efficiently and determine such questions as the optimum size for stockpiles, the best overlap of brightness and impurities for differing products and the best ways of using the highest grade resource. The MISG team made progress towards building models based on two different approaches and provided ideas for a third model.

Background

The Steering Committee for the meeting included representatives from the Departments of Mathematics at two universities, CSIRO DMS, CRA and WMC. Generous financial support in the form of travel grants was provided by CSIRO under the DMS Applied and Industrial Mathematics Program, the Department of Industry, Science and Technology under the Science and Technology Awareness Program, and four companies, Amcor, ICI Plastics, Kodak and Sola International. ANZIAM also provided financial support. DEC in Melbourne kindly loaned three alpha workstations for the week and these were used intensively on Kodak, Kraft and Uncle Tobys projects. The Science Multimedia Teaching Unit at the University of Melbourne generously sponsored the development of the MISG Web site. Please have a browse at

http://macserver.maths.mu.oz.au/misg/Default.html

Support Activities

In January 1996, the ARC Strategic Review Of Mathematical Sciences Research and Advanced Mathematical Services in Australia released its report Mathematical Sciences: Adding to Australia . It details the state of mathematical sciences in Australia and also identifies 10-15 year goals for the discipline. Dr Noel Barton was the Executive Officer and editor of the Review and on the Tuesday he outlined the recommendations and led a lively discussion on its findings.

As usual, useful publicity for the mathematics profession was generated by the MISG. The recent highlight was ABC TV Quantum report (Nov 1) on the Kodak project brought to MISG 1995. The publicity helps community awareness of the skills and resources provided by mathematicians.

Conclusion

The MISG plays an important role in the Australian industrial and academic environment and helps to foster valuable and long-term links. The MISG continues to build on its success and the Department of Mathematics at the University of Melbourne is pleased to sponsor this forum. The next MISG will be held 27-31 January, 1997 at the University of Melbourne, the week before the ANZIAM meeting in Lorne, Victoria. I hope to see you there!


Department of Mathematics
The University of Melbourne
misg@maths.mu.oz.au


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