Given a graph G = (V,E) and a positive integer t ≥ 2, the task in the vertex cover Pt (V CPt) problem is to find a minimum subset of vertices F ⊆ V such that every path of order t in G contains at least one vertex from F . The V CPt problem is NP-complete for any integer t ≥ 2. Recently, the authors presented a dynamic programming algorithm with runtime 4 · n that can solve the V CP3 problem in...

This document, combining specifications derived from possible demonstrator scenarios by WP4, and feasibility studies on hardware components for haptic actuation and sensing by WP3, corresponds to checkpoint CP3/4. Both existing hardware and foreseeable developments during the Immersence propject have been considered. The target of the report is to provide the necessary material and information ...

We develop a global twistor correspondence for pseudo-Riemannian conformal structures of signature (++−−) with self-dual Weyl curvature. Near the conformal class of the standard indefinite product metric on S2 × S2, there is an infinitedimensional moduli space of such conformal structures, and each of these has the surprising global property that its null geodesics are all periodic. Each such c...

We give explicitly the surgeries governing the changes of quotient manifolds of real algebraic surfaces in CP3. We also make a number of general observations regarding quotients of complex surfaces under antiholomorphic involutions.

By lifting full Yang-Mills theory to R4 × S2 , Mason et al. obtained MHV vertices by gauge transformation. Their Lagrangian depended on long intricate twistor manipulations. Spinor S2 harmonics give a one page proof, eliminating all the CP3 apparatus.

The aim of this study was to investigate the fracture strength of endodontically treated teeth restored with different posts and variable ferrule heights. Sixty freshly extracted human canines were treated endodontically and randomly assigned to 6 groups (n=10), being restored with custom-made cast post-and-core (CP0 and CP3 groups), prefabricated post and composite resin core (PF0 and PF3 grou...

We present the main ingredients of twistor theory leading up to and including the Penrose-Ward transform in a coordinate algebra form which we can then ‘quantise’ by means of a functorial cocycle twist. The quantum algebras for the conformal group, twistor space CP3, compactified Minkowski space CM and the twistor correspondence space are obtained along with their canonical quantum differential...