This paper describes a framework currently under development for modelling, simulation, and verification of relay interlocking systems as used by the Danish railways. The framework is centred around a domain-specific language (DSL) for describing such systems, and provides (1) a graphical editor for creating DSL descriptions, (2) a validator for checking that DSL descriptions are statically wel...

It is an open problem, posed in [3], to determine the minimal k such that an open flexible k-chain can interlock with a flexible 2-chain. It was first established in [5] that there is an open 16-chain in a trapezoid frame that achieves interlocking. This was subsequently improved in [6] to establish interlocking between a 2-chain and an open 11-chain. Here we improve that result once more, esta...

BACKGROUND Intramedullary (IM) nailing is the treatment of choice among orthopaedic surgeons for tibial shaft fractures. However, because of the close proximity of the nail's insertion site to the anterior medial (AM) meniscal root on the tibial plateau, there is increased risk of iatrogenic injury to the meniscal root during nailing. PURPOSE To quantify the area of the AM meniscal root footp...

Filling a gap in the interlocks literature which has been largely centered on the West, we present preliminary data on the pattern of interlocking directorates among the top 200 largest corporations in pre-1997 Hong Kong. Then we identify four separate groups of firms in Hong Kong, and suggest propositions based on the resource dependence perspective on the critical relationships among their in...

For supporting the analysis of railway interlocking systems in the early stage of their design we propose the use of model checking. We investigate the use of the formal modelling language CSP and the corresponding model checker FDR. In this paper, we describe the basics of this formalism and introduce our formal model of a railway interlocking system. Checking this model against the given safe...

Interlocking nailing is a widely accepted and performed treatment for tibial shaft fractures. The addition of percutaneously placed transfixation screws increases the stabilisation provided by intramedullary nailing; however, the technical complexity associated with the procedure has introduced new potential complications. We report a pseudoaneurysm of the anterior tibial artery caused by a pro...

In this paper we present a verification strategy for signalling principles for the control of a railway interlocking system written in ladder logic. All translation steps have been implemented and tested on a real-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development of a mathematical model of a railway interlocking system and the trans...

Railway interlocking systems still represent a challenge for formal verification by model checking: the high number of complex interlocking rules that guarantee the safe movements of independent trains in a large station makes the verification of such systems typically incur state space explosion problems. We describe a study aimed to define a verification process based on commercial modelling ...

PURPOSE Rigid interlocking nailing for femoral shaft fracture is ideal for use in adolescents in terms of stability of the fracture and convenience for the patient. However, numerous authors have reported that rigid interlocking nailing has some limitations in this age group due to the risk of complications. We evaluated the results of intramedullary nailing for femoral shaft fractures with an ...