We continue a study of unconditionally secure all-or-nothing transforms (AONT) begun in [12]. An AONT is a bijective mapping that constructs s outputs from s inputs. We consider the security of t inputs, when s − t outputs are known. Previous work concerned the case t = 1; here we consider the problem for general t, focussing on the case t = 2. We investigate constructions of binary matrices fo...

in this paper, we consider locally graded groups in which every non-permutable subgroup is soluble of bounded derived length.

All-to-all personalized communication, also known as complete exchange, is one of the most dense communication patterns in parallel computing. In this paper, we propose new indirect algorithms for complete exchange on all-port ring and torus. The new algorithms fully utilize all communication links and transmit messages along shortest paths to completely achieve the theoretical lower bounds on ...

Let F, G and H be non-empty graphs. The notation F → (G,H) means that if any edge of F is colored by red or blue, then either the red subgraph of F con- tains a graph G or the blue subgraph of F contains a graph H. A graph F (without isolated vertices) is called a Ramsey (G,H)−minimal if F → (G,H) and for every e ∈ E(F), (F − e) 9 (G,H). The set of all Ramsey (G,H)−minimal graphs is denoted by ...

there is an increasing policy emphasis on the integration of care, both within the healthcare sector and also between the health and social care sectors, with the simple aim of ensuring that individuals get the right care, in the right place, at the right time. however, implementing this simple aim is rather more complex. in this editorial, we seek to make sense of this complexity and ask: what...