CLIFF RAILWAYS.

Cliff hangers

The peregrine falcon holds a special place in the minds of environmentalists and conservation biologists. The crash in its population throughout the 1950s and 60s was linked to the rapidly increasing use of agricultural organochlorine pesticides which led to a thinning of the birds’ eggshells and dramatic breeding failure. Since the widespread ban on the use of these chemicals, populations have...

Cliff hanger

The asparagus season has recently ended for northern hemisphere crops. Tradition has it that, at the summer solstice, growers stop cutting spears to allow the plant to grow and produce enough resources to generate spears for the next spring’s crop. The plant is becoming increasingly fashionable and production is increasing to meet demand. But the cultivated asparagus has a wild relative that is...

CLiFF Notes

On Generalized Random Railways

We consider a random generalized railway defined as a random 3-regular multigraph where some vertices are regarded as switches not allowing traffic between any pair of attached edges. It is shown that the probability that the generalized railway is functioning is linear in the proportion of switches. Thus there is no threshold phenomenon for this property.

Safety Functions in Railways

There are several ways to describe and structure safety rules for railways, and a few examples are given in the report. A tentative holistic framework for describing safety features in relation to safety rules is presented. The approach has been applied on rules needed to regulate the communication between different railway organisations and other parties.