Geo-replicated, distributed data stores that support complex online applications, such as social networks, must provide an “alwayson” experience where operations always complete with low latency. Today’s systems often sacrifice strong consistency to achieve these goals, exposing inconsistencies to their clients and necessitating complex application logic. In this paper, we identify and define a...

We consider a variation of the Cops and Robber game where the cops can only see the robber when the distance between them is at most a fixed parameter `. We consider the basic consequences of this definition for some simple graph families, and show that this model is not monotonic, unlike common models where the robber is invisible. We see that cops’ strategy consists of a phase in which they n...

The Cops and Robbers game as originally defined independently by Quilliot and by Nowakowski andWinkler in the 1980s has beenmuch studied, but very few results pertain to the algorithmic and complexity aspects of it. In this paper we prove that computing the minimumnumber of cops that are guaranteed to catch a robber on a given graph is NP-hard and that the parameterized version of the problem i...

Communities of Practices (CoPs) are informal structures within organizations that bind people together through informal relationships and the sharing of expertise and experience. As such, they are effective tools for the creation and sharing of organizational knowledge, and, increasingly, organizations are adopting them as part of their knowledge management strategies. In this paper, we examine...

We theoretically analyze the Cops and Robber Game for the first time in a multidimensional grid. It is shown that in an n-dimensional grid, at least n cops are necessary if one wants to catch the robber under all possible initial configurations. We also present a set of cop strategies for which n cops are provably sufficient to catch the robber.

Cryptosporidiosis is predominantly caused by two closely related species of protozoan parasites the zoonotic Cryptosporidium parvum and anthroponotic Cryptosporidium hominis which diverge phenotypically in respect to host range and virulence. Using comparative genomics we identified two genes displaying overt heterogeneity between species. Although initial work suggested both were species speci...

Communities of practice (CoPs) are increasingly recognised as an important mechanism through which goods are created. Current conceptualisations of CoPs don’t, however, acknowledge adequately the inherent tensions between practices and the organisations within which they function. This failure leads to an inadequate understanding of ways in which organisations should interact with relevant CoPs...

This paper reviews prior research on individual participation in online communities of practice (CoPs). It examines how the concept of CoP has been applied in IS and what theories have been applied to explain knowledge sharing behaviours in online CoPs. To integrate findings in prior empirical IS studies, the paper drew on literature on relationship marketing to re-conceptualize participation i...

The COPS (Classification Of Protein Structures) web server provides access to the complete repertoire of known protein structures and protein structural domains. The COPS classification encodes pairwise structural similarities as quantified metric relationships. The resulting metrical structure is mapped to a hierarchical tree, which is largely equivalent to the structure of a file browser. Exp...

In this short paper we study the game of cops and robbers, which is played on the vertices of some fixed graph G. Cops and a robber are allowed to move along the edges of G, and the goal of cops is to capture the robber. The cop number cðGÞ of G is the minimum number of cops required to win the game. Meyniel conjectured a long time ago thatOð ffiffiffi n p Þ cops are enough for any connectedG o...