Addressing performance requirements in the FDT-based design of distributed systems

The development of distributed systems is generally regarded as a complex and costly task, and for this reason formal description techniques such as LOTOS and ESTELLE (both standardized by the ISO) are increasingly used in this process. Our experience is that LOTOS can be exploited at many stages on the design trajectory, from requirements specification to implementation, but that the language elements do not allow direct formalization of performance requirements. To avoid duplication of effort by using two formalisms with distinct approaches, we propose a design method that incorporates performance constraints in an heuristic but effective manner

A note on the gap between rank and border rank

We study the tensor rank of the tensor corresponding to the algebra of n-variate complex polynomials modulo the dth power of each variable. As a result we find a sequence of tensors with a large gap between rank and border rank, and thus a counterexample to a conjecture of Rhodes. At the same time we obtain a new lower bound on the tensor rank of tensor powers of the generalised W-state tensor. In addition, we exactly determine the tensor rank of the tensor cube of the three-party W-state tensor, thus answering a question of Chen et al.Comment: To appear in Linear Algebra and its Application

De ziekenhuisfinanciering: uitdagingen, sterktes en kansen tot verbetering

Hospital care is an important link of our healthcare system. The development of an appropriate organization and financing design that stimulates effective, fair and qualitative care is therefore a crucial challenge. In today’s context, Belgian hospital care is being financed in a complex and fragmented way. There are different financial flows that are being designed in close collaboration with the sector. This leads to a rather opaque system, sometimes with very little coordination between the different financial flows. The way physicians and hospitals are being paid needs to be reconsidered and will need to reward quality one way or the other. The patients themselves will also need to take up new roles, and sick funds will need to be involved in improving the current hospital financing system

Deviations from Gaussianity in deterministic discrete time dynamical systems

In this paper we examine the deviations from Gaussianity for two types of random variable converging to a normal distribution, namely sums of random variables generated by a deterministic discrete time map and a linearly damped variable driven by a deterministic map. We demonstrate how Edgeworth expansions provide a universal description of the deviations from the limiting normal distribution. We derive explicit expressions for these asymptotic expansions and provide numerical evidence of their accuracy

The drama(turgy) of non-belonging : Jeroen Coppens in dialogue with Motus on sharing identity in panorama

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