More and more CoPs have chosen virtual environments and services to support their activities. However, recent research has underlined several problems: the lack of adequate scaffolding in terms of technical support and appropriate use of technology for communication and collaboration, the lack of tools and virtual environments to support real-life problem-solving and the reification of knowledg...

This paper is a contribution to the classical cops and robber problem on a graph, directed to two-dimensional grids and toroidal grids. These studies are generally aimed at determining the minimum number of cops needed to capture the robber and proposing algorithms for the capture. We apply some new concepts to propose a new solution to the problem on grids that was already solved under a diffe...

Communities of practice (CoPs) have become increasingly influential within management literature and practice since being identified as an important mechanism through which individual, organizational and social knowledge is held, transferred and created. Their theoretical roots lie in the situated learning approach, but they have spread to the field of knowledge management, emerging as an impor...

In cops and robber games a number of cops tries to capture a robber in a graph. A variant of these games on undirected graphs characterises tree width by the least number of cops needed to win. We consider cops and robber games on digraphs and width measures (such as DAG-width, directed tree width or D-width) corresponding to them. All of them generalise tree width and the game characterising i...

BACKGROUND Effective implementation of change in healthcare organisations involves multiple professional and organisational groups and is often impeded by professional and organisational boundaries that present relatively impermeable barriers to sharing knowledge and spreading work practices. Informed by the theory of communities of practice (CoPs), this study explored the effects of intra-orga...

BACKGROUND Coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci are normal commensals of the skin and mucosa, but are also opportunist pathogens. Meticillin-resistant (MR) and multidrug-resistant (MDR) isolates are increasing in human and veterinary healthcare. Healthy humans and other animals harbour a variety of staphylococci, including MR-CoPS and MR-CoNS. The main aims of t...

The guarding game is a game in which several cops try to guard a region in a (directed or undirected) graph against a robber. The robber and the cops are placed on the vertices of the graph; they take turns in moving to adjacent vertices (or staying), cops inside the guarded region, the robber on the remaining vertices (the robber-region). The goal of the robber is to enter the guarded region a...

We examine the zero-visibility cops and robber graph searching model, which differs from the classical cops & robber game in one way: the robber is invisible. We show that this model is not monotonic. We also provide bounds on both the zero-visibility copnumber and monotonic zerovisibility copnumber in terms of the pathwidth.

The paper aims at showing how Participatory Design contributes to the understanding of learning processes related to Communities of Practice (CoPs) and, at the same time, to the design and implementation of Web Services to support organisational and individual learning in CoPs. This research builds on the European PALETTE project.

We give two characterizations of the graphs on which k cops have a winning strategy in the game of Cops and Robber. One of these is in terms of an order relation, and one is in terms of a vertex ordering. Both generalize characterizations known for the case k = 1. © 2012 Elsevier B.V. All rights reserved.