Comprehensibility of UML-based Formal Model – A Series of Controlled Experiments

This paper summarises two controlled experiments conducted on a model that integrates the use of semi-formal notation, the Unified Modelling Language (UML) and a formal notation, B. The experiments assessed the comprehensibility of the model, namely UML-B. The first experiment compared the comprehensibility of a UML-B model and a B model. In the second experiment, the model was compared with an Event-B model, a new generation of B. The experiments assessed the ability of the model to present information and to promote problem domain understanding. The measurement focused on the efficiency in performing the comprehension tasks. The experiments employed a cross-over design and were conducted on third-year and masters students. The results suggest that the integration of semi-formal and formal notations expedites the subjects’ comprehension tasks with accuracy even with limited hours of training

Can worms be controlled by correct feeding?

THE extensive losses which result from the ravages of internal parasites are a matter of serious concern. Livestock owners realise this all too well and welcome advice concerning control measures which can be adopted. Unfortunately, it is not possible to give clear cut advice on the subject. Much publicity is given to the use of drugs which will expel the worms. Various systems of strategic drenching have been developed. It is well to remember, however, that drenching is only one of many methods which can be used to control worm infestation. In this talk attention will be concentrated on experimental evidence which shows that good husbandry in general, and good feeding in particular, may greatly reduce the worm burden carried by livestock

Cobalt

Cobalt is one of the most interesting of the so-called trace elements. Particularly is this so to West Australians as the use of cobalt has permitted farmers to rear healthy sheep and cattle where previously this was impossible. Also, it was in this State that Filmer and Underwood carried out much of the fundamental work which led to the discovery of the vital importance of cobalt

Vitamin A supplements for sheep and cattle

Vitamin A is essential for the health and wellbeing of all animals and birds. This vitamin is obtained by grazing animals from carotene, an orange pigment present in green plants. When plant material matures and dies, the carotene is quickly destroyed by sunlight. This means that dry herbage in the field becomes worthless as a source of Vitamin A

The use of rock phosphate from Christmas Island in poultry rations

Bonemeal, or products derived from bone, are the orthodox source of additional phosphorus where this is needed in livestock rations. Supplies of bones are limited, however, and there is an urgent need for alternative sources of phosphorus suitable for inclusion in compound feeding stuffs. Poultry farmers in Western Australia have had recurrent difficulty in obtaining regular supplies of bonemeal or boneflour. Dairy farmers were faced with the same problem but this now being overcome by the use of ground rock phosphate obtained from Christmas Island (Snook 1955)

Mineral supplements

TJRODUCTIVE dairy cows have a high mineral requirement. A deficiency can cause lowered milk production and poor health may result if it is not corrected

Cobalt - its use to control wasting disease

Cobalt is one of the most interesting of the so-called trace elements. Particularly is this so to West Australians as the use of cobalt has permitted farmers to rear healthy sheep and cattle where previously this was impossible. Also, it was in this State that Filmer and Underwood carried out much of the fundamental work which led to the discovery of the vital importance of cobalt