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Detector makes sweeping improvements

When you take the bus to work, or drive to the shops, you expect the road to be clean, not cluttered with litter or scattered with stones. Street sweeping is something that’s easy to take for granted, but there’s more to the job that a quick flick of a broom. Efficient cleaning relies on vehicle drivers selecting and controlling brushes according to the debris to be cleared.

While operators concentrate on following the kerb safely they have little time for fine tuning the sweeping process. So researchers from the University of Surrey have decided to give street sweeping a scientific fillip. By identifying the rubbish ahead, a computer can automatically choose the best brush or stroke for maximum efficiency.

Graham Parker and his team from the School of Mechanical and Materials Engineering have closely investigated the sweeping action of rotary brushes found on sweeping vehicles. He categorises two forms of brush. ‘Cutters’ are stiff when forced down onto the surface. They are best used for compacted material like sand on the road. The tines on ‘flicking’ brushes, by contrast, are better designed to throw loose debris into the path of the vacuum hose underneath the sweeper truck.

“Although the operation of the road sweeping vehicle is straightforward,” says Professor Parker, “the choice of which brush to fit and its angle to the ground clearly affects the overall brushing performance when the debris types vary. A sensor system that could determine the most appropriate brush would make a better and more efficient machine.”

The team’s debris detector comprises a digital camera and a laser. Image processing of the camera image allows computers to pinpoint debris and calculate its size and shape.

“Image processing usually requires a lot of computing time, but in a sweeper vehicle you need real-time calculations,” explains Professor Parker. “By using the laser we can build up a 3-D profile of the road without intense processing, just identifying bright pixels in a relatively dark background. When, and only when more than this information is needed to analyse a scene more computer intensive processing techniques are used.”

Tests so far show than this laser striping system can locate and calculate the shape of most types of litter, from large objects that would damage the machine to small items that like bolts and nuts. For debris, such as sand, gravel and leaves that spread over a wide area, extra image processing is important: sand and leaves require quite different brushing styles.

Once the boundaries of the debris have been identified by laser striping, the computer then compared the pixel intensity over the surface. The varying intensity provides an indication of surface roughness, and therefore a guide to the type of debris. “We found that our smooth lab floor was easily distinguished from wood chip, for instance. This method should be able to distinguish gravel from leaves from sand.”

“We now hope to integrate our understanding of brushing with our sensor and predictive analysis,” concludes Professor Parker. “Hopefully we can improve street cleaning and make life easier for the vehicle operators.”

A talking point for intensive care

A stay in an intensive care unit may only be short, but it is a worrying time for all concerned. On top of the anxieties regarding recovery, many patients, with breathing tubes in their throats, are unable to speak. A research project has now developed a computerised system that allows patients to communicate better by choosing sentences from a pre-programmed selection.

“Many patients in intensive care attempt to mouth words, but if they have tubes in their mouth, lip reading is difficult. Weakness can affect the movement of their hands and arms and make writing or gesturing hard too,” explains Professor Ian Ricketts from Dundee University. “The inability to communicate can be upsetting for patients and while nursing staff are highly skilled at anticipating the communication needs of patients, they say it is time consuming and difficult.”

Professor Ricketts has led a team from the Department of Applied Computing that has designed a system which enables patients to speak to staff, relatives and friends through a computer. They can navigate through a database of over 250 phrases using a touch-screen, a mouse or options using a single switch. The computer then uses speech synthesis software to utter the sentence.

“The selection of phrases available are wide ranging,” says Professor Ricketts. “We asked nurses to suggest sentences for particular topics and used their responses, along with observations of patient communication in our local intensive care unit, to compile a core set of phrases.”

Along with these stock phrases the research team devised a way that would supply patients with personalised phrases too. “We have a questionnaire that is completed by a family member and the answers are incorporated into template phrases to personalise them,” explains Professor Ricketts. “A patient can then enquire about a family member by name, for instance.”

The computer interface is simple to use, so patients easily learn how to use it. Phrases are grouped within eight colour-coded topic areas, such as “Family, friends” or “Feelings”. Trials so far show that patients quickly learn to control the system and successfully communicate. Nursing staff overwhelmingly support the concept of computer-assisted communication.

“Preliminary trial results have so far been encouraging, though of course we are still refining our prototype system, especially the navigation of phrases,” Professor Ricketts notes. “At the moment some phrases are hard to find or don’t exist, and we are also looking at incorporating animation into the navigation as research suggests that animation makes interaction with computer systems easier. Our main concern, however, is to make the system much smaller so that it doesn’t obstruct nursing staff or restrict their view of, and access to, the patient. Ideally a small, robust, bedside system will make communication much more natural and take one worry off the minds of patients, staff and relatives alike.”

Statistics that count in the animal kingdom

Statistics that count in the animal kingdom

A team of British statisticians is pioneering new ways of analysing information about how animals survive in the wild. The new techniques will give biologists a better understanding of the viability of populations of particular species. It will also help them to devise conservation programmes.

At the University of Kent at Canterbury, Professor Byron Morgan is developing statistical tools to improve the interpretation of the data on animal survival. Researchers can gather vast amounts of data over many years. But it can be difficult to make sense of the information and to relate it to what is actually happening to the population.

Data on the survival rates of animal populations not only yield information about the species itself but can also be an important indicator of environmental change. One way of obtaining this sort of information is to capture some of the population, mark them by placing a ring on the leg, for example, and then release them. The researcher then records sightings of marked animals along with details of the bodies of dead animals they find.

Professor Morgan’s team has devised a way of combining data from the recovery of dead animals with that from observations of surviving animals. This is significant because until now researchers have usually analysed the two types of information have independently. By integrating the data, experts in animal populations can make much more realistic conclusions.

The Canterbury team has also written software to help to choose the best statistical model for the type of data at hand. Data gathered from the field can be highly complex. Many factors can affect survival rates. With the new software, the operator feeds in the initial data, the software then prompts the researchers to indicate the most important parameters.

Using the data and the information from the operator, the system can help to select the best model population. Furthermore, the Kent team has developed a way of verifying if a particular statistical model is suitable for the kind of data that it is being presented with. The system allows the user to ‘interrogate’ any model to see if it is capable of analysing the data meaningfully.

The right (and left) way to design packaging

Forget about food safety and hygiene. Just opening a packet of sandwiches or a tin of sweetcorn can be a hazard – especially if you are left-handed, stubborn or poor at making decisions under pressure. Anyone can slip when opening a jar of pickle, but recent research puts the onus on package designers and engineers to cater for different consumer characteristics and personality traits in their designs.

Dr Belinda Winder and her colleagues from the Department of Mechanical Engineering at Sheffield University asked 200 shoppers about their experiences with different types of food packaging. The shoppers also completed personality questionnaires.

The results show that ‘natural born worriers’ and those who have already suffered a serious injury on packaging complain the most about designs. “This group of consumers is most anxious about opening packets,” says Dr Winder. “However, those scoring highly in neuroticism were actually no more likely to injure themselves than anyone else.”

While the worriers are prone to complain, left-handed consumers suffer the most. “This is a world dominated by right-handed people, designed by them and, perhaps more to the point,” notes Dr Winder, “designed for them too. Although there are no differences in the types of accidents that left-handed people reported, it seems that left-handers are at a disadvantage when trying to open every type of packaging.”

Certain personality traits can also lead to a consumer’s comeuppance, the researchers found. In particular, fuzzy decision making under pressure appears to contribute to injuries. Moreover, ‘socially resistant’ individuals – those who do not ask for help – tend to suffer the most severe accidents. These people are probably the ones who will not be beaten; they resort to sharp knives, ‘home remedies’ and extreme measures to get at their food.

“The results of this study indicate that accidents and injuries from food and drink packaging cannot be attributed simply to poor designs,” says Dr Winder. “Individual differences and attitudes to products affect the way we try to open them. But it is important for designers to recognise the broad spectrum of consumers and take into account their characteristics and behaviour when planning new packaging designs.”

Wireless advances boost mobile mulitimedia communications

Wireless advances boost mobile mulitimedia communications

A wide range of innovations being made at Southampton University’s Department of Electronics and Computer Science is enabling wireless telephone networks to be extended to carry high-quality video, speech, handwriting and graphics for advanced multimedia applications.

The work, by Southampton’s Mobile Multimedia Communications Team (MMCT) in Professor Raymond Steele’s Communications Group efficiently exploits available wireless ‘bandwidths’ to deliver robust, high-quality multimedia communications to anyone, at any location. The bandwidth of a communications link determines the amount of digital ‘bits’ of information it can carry. Speech conversations of acceptable quality can be encoded at rates as low as 5600 bits per second (bps), but moving-image video typically needs significantly higher transmission speeds.

How the Digital Assistant may look Multimedia communications can be handled reliably and efficiently using optical fibres, cables and other high-speed ‘broadband’ networks, which are relatively free from external interference. Users of wireless communications, however, move through a variety of environments, such as a tunnel, which are hostile to the propagation of radio waves. Maintaining consistent mobile reception quality therefore requires complex signal processing.

The MMCT has developed a range of bandwidth-efficient transmission methods for delivering multimedia services, including new encoder/decoder (codec) techniques. These translate video, speech and other signals into ‘compressed’ digital codes that need fewer bps during transmission, with the signal retranslated into the original format by the decoder. Codecs are implemented as micro-chips in users’ devices.

The MMCT’s innovations, many of which were made on EPSRC-funded projects, are targeted towards optimising the overall performance of wireless networks by creating systems that automatically adapt and reconfigure themselves to maintain optimum performance levels, for instance by programmable codecs. This ensures the ever-changing demands of mobile users are met in the most efficient way.

Such overall system optimisation is the team’s prime contribution to making feasible the ubiquitous use of ‘multimode’ devices which combine the capabilities of a mobile phone, hand-held ‘palmtop’ computer, radio receiver, videophone and electronic handwriting tablet. Much industrial interest has been shown in this work.

The MMCT has also been collaborating with academic/industrial consortia on the EU-funded FIRST programme developing a reconfigurable multimedia terminal and MEDIAN project for creating high-speed local wireless networks within buildings.

Researchers discover that our windows are cleaner than previously thought – Good news for energy efficiency

Researchers discover that our windows are cleaner than previously thought – Good news for energy efficiency

Britain’s windows are cleaner than they were originally thought to be, researchers have discovered. The finding is important because it will allow architects to design buildings that are more energy-efficient.

The research has been carried out by a team led by Peter Tregenza and Steve Sharples in the School of Architecture at the University of Sheffield. The project was funded by the Engineering and Physical Sciences Research Council.

An important factor in building design is the amount of daylight that will enter through the windows. To calculate this, one of the things that architects must take into account the likelihood of dirt building up on the glass, obscuring some of the light.

‘The amount of light coming through a window can be reduced by as much as half,’ says Professor Tregenza. ‘A lot of this loss is due to things like overhangs and blinds, but a significant amount can be lost because of accumulation of dirt on the window pane.’

Limbering up for quality animation

The Titanic rears high above the water. Hanging from the balustrade, terrified passengers look down into the icy waters as their fingers slip. Fortunately for the actors, this is where the computer graphics kick in, simulating the life like movements of limbs as bodies begin to drop into the sea.

The standard methods of computer modelling require human subjects to wear reflective patches. Cameras film the person and image analysis software tracks the movement of the patches. The computer builds up a picture of how the person’s joints move. Originally the application was applied to clinical diagnosis, but the entertainment industry regularly uses the same technology. It can simulate people moving realistically in crowd scenes, stunt shots – or falling from sinking ships.

A web of desire

Why have cotton when you can have silk? Perhaps the real question should be: why reel it off the silkworm cocoon when you could make it in a factory?

Professor Fritz Vollrath and a team of researchers in the Department of Zoology at Oxford University are investigating techniques for producing artificial silk. Instead of the silkworm, the scientists have focused their attention on another silk producer – spiders.

Web spider silks have many exciting properties. They can be incredibly tough, with a capacity to absorb energy that equals the nylon filaments in bullet-proof vests. Yet spider silk is extremely eco-friendly: fully biodegradable, it is produced at ambient temperatures from water soluble, renewable materials.

“Spider silk is an amazing material, and I think we can copy it in the very near future,” asserts Professor Vollrath.