We prove a new congruence result for the π-calculus: bisimilarity is a congruence in the sub-calculus that does not include restriction nor sum, and features top-level replications. Our proof relies on algebraic properties of replication, and on a new syntactic characterisation of bisimilarity. We obtain this characterisation using a rewriting system rather than a purely equational axiomatisati...

We propose a novel algebraic characterisation of the classical notion of validity in terms of boolean rings, called entailment multipliers. We demonstrate the existence of such multipliers and show how they can be used to derive stronger entailment statements. An interesting property of multipliers lies in their behaviour as invariants in a proof, a fact that is used to show how several inferen...

Although the probability of defect detection using magnetic flux leakage (MFL) inspection is sufficient for most applications for which it is used; inspection of ferromagnetic pipeline, wire rope, etc., accurate defect characterisation is problematic. The use of pulsed excitation in conjunction with MFL provides an opportunity for the extraction of depth information from the MFL signal using an...

The characterisation of stem cells is of vital importance to regenerative medicine. Failure to separate out all stem cells from differentiated cells before therapies can result in teratomas - tumours of multiple cell types. Typically, characterisation is performed in a destructive manner with fluorescent assays. A truly non-invasive method of characterisation would be a major breakthrough in st...

We define a new general rule-based nonmonotonic framework which allows an external acyclic priority relation between rules to be interpreted in several ways. Several entailment semantics are defined via a constructive digraph, with one being given a declarative fixed-point characterisation as well. Each of these semantics satisfies Principle 1 of [Brewka and Eiter 1999]. The framework encompass...

We have realised a microsystem for the culture and electrical characterisation of epithelial cell layers for cell-based diagnostic applications. The main goal of this work is to achieve both cell culture and impedimetric and potentiometric characterisation on a single device. The miniaturised cell culture system enables the uses of scarce epithelial cells, as obtained from transgenic mice or fr...

This paper describes an evaluation of a characterisation framework to analyse mobile work scenarios in order to make corresponding software systems. The framework identifies complexity issues to be taken into account when implementing a system. The framework can also be used to elicit requirements from a scenario. Three research questions are investigated in this evaluation: 1) Can the framewor...

A toolset for performance analysis of parallel systems, PACE, is presented in this report. In this toolset expert knowledge about the performance evaluation techniques is not required as a prerequisite for the user. Instead a declarative approach to the performance study is taken by describing the application in a way that is both intuitive to the user, but can also be used to obtain performanc...

A foundational theorem of Laman provides a counting characterisation of the finite simple graphs whose generic bar-joint frameworks in two dimensions are infinitesimally rigid. Recently a Laman-type characterisation was obtained for frameworks in three dimensions whose vertices are constrained to concentric spheres or to concentric cylinders. Noting that the plane and the sphere have 3 independ...

The growing demand for performance observed in many organisations can still be considered the main motivator for the evolution of high performance computing and, more recently, cloud environments. Part of this demand regards the need to deal with large and complex datasets, called big data. Performance improvement in such environments begins to be limited by energy consumption. Workload charact...