Optimising the application of the Hough transform for automatic feature extraction from geoscientific images

We have adapted the Hough transform to extract linear features successfully from geoscientific datasets. The Hough transform is used in an automatic technique, which makes use of a parameter space to describe features of interest in images. This method has been widely applied in machine vision for recognition of features in highly structured images. Geoscientific data is more demanding. Features of interest within scenes of natural environments exist on all scales, are often partially obscured and the images are usually noisy. Pre-processing of images before the HT is essential. Adaptations of the HT to cope with particular properties of geoscientific data include: optimising the dimensions of the discrete transform domain; using feature-modelling to cancel lines found; transforming multi-scale tiles of the original image and correcting amplitudes in the transformed domain to account for the position of features. These specific adaptations produce a method for automatic feature detection which requires the user to select only two parameters. Output of the procedure is rich in feature content and accurate, leaving a clean result for statistical analysis. This optimised HT is robust for natural scenes, coping in particular with short line-segments.     

Photochemical degradation of thermoplastics

The general mechanism of polymer photodegradation is outlined, and various aspects are then discussed with reference to polyolefins, particularly polyethylene. It is shown that various impurities accelerate degradation and that carbonyl groups play a complex role in the process. Polyolefins can be stabilised against photodegradation by incorporation of suitable u.v. stabilisers or pigments, and the principles involved, including the synergism between u.v. stabilisers and antioxidants, are discussed.     

Context sharing in a ‘real world’ ubicomp deployment

While the application of ubicomp systems to explore context sharing has received a large amount of interest, only a very small number of studies have been carried out which involve “real world” use outside of the lab. This article presents an in-depth analysis of context sharing behaviours that built up around use of the Hermes interactive office door display system received during deployment. The Hermes system provided a groupware application supporting asynchronous messaging facilities, analogous to a digital form of Post-it notes, in order to explore the use of situated display systems to support awareness and coordination in an office environment. From this analysis we distil a set of issues relating to context sharing ranging from privacy concerns to ease of use; each supported through qualitative data from user interviews and questionnaires.     

Rapid Determination of Dextrose Equivalent by Cryoscopy

This paper describes the development of a novel method for determination of Dextrose Equivalent of Malto-dextrins and glucose syrups. The new method uses depression of freezing point as a measure of the number of molecules in solution; Dextrose Equivalent is also a measure of the number of molecules in solution. The advantages of the cryoscopic method are its inherent rapidity (2 min per determination), its precision and the fact that previous expertise is not required.