Provenance is a standardised record that describes how entities, activities, and agents have influenced a piece of data; it is commonly represented as graphs with relevant labels on both their nodes and edges. With the growing adoption of provenance in a wide range of application domains, users are increasingly confronted with an abundance of graph data, which may prove challenging to process. Graph kernels, on the other hand, have been successfully used to efficiently analyse graphs. In this paper, we introduce a novel graph kernel calledprovenance kernel, which is inspired by and tailored for provenance data. We employ provenance kernels to classify provenance graphs from three application domains. Our evaluation shows that they perform well in terms of classification accuracy and yield competitive results when compared against existing graph kernel methods and the provenance network analytics method while more efficient in computing time. Moreover, the provenance types used by provenance kernels are a symbolic representation of a tree pattern which can, in turn, be described using the domain-agnostic vocabulary of provenance. Therefore, provenance types thus allow for the creation of explanations of predictive models built on them.

We consider two simple asynchronous opinion dynamics on arbitrary graphs where every node u of the graph has an initial value ξu(0). In the first process, which we call the NodeModel, at each time step t ≥ 0, a random node u and a random sample of k of its neighbours υ1, υ2, ... , υk are selected. Then, u updates its current value ξu(t) to [EQUATION], where α ∈ (0, 1) and k ≥ 1 are parameters of the process. In the second process, called the EdgeModel, at each step a random pair of adjacent nodes (u, υ) is selected, and then node u updates its value equivalently to the NodeModel with k = 1 and υ as the selected neighbour.

We consider a population protocol version of the SIR model. In every round, an individual is chosen uniformly at random. If the individual is susceptible, then it becomes infected w.p. $\beta I_t/N$, where $I_t$ is the number of infections at time $t$ and $N$ is the total number of individuals. If the individual is infected, then it recovers w.p. $\gamma$, whereas, if the individual is already recovered, nothing happens. We prove sharp bounds on the probability of the disease becoming pandemic vs extinguishing early (dying out quickly). The probability of extinguishing early, $\Pr{\mathcal{E}_{ext}}$, is typically neglected in prior work since most use (deterministic) differential equations. Leveraging on this, using $\Pr{\mathcal{E}_{ext}}$, we proceed by bounding the expected size of the population that contracts the disease $\mathbf{E}\left[R_\infty\right]$. Prior work only calculated $\mathbf{E}\left[R_\infty | \overline{\mathcal{E}_{ext}}\right]$, or obtained non-closed form solutions. We then study the two-country model also accounting for the role of $\Pr{\mathcal{E}_{ext}}$. We assume that both countries have different infection rates $\beta^{(i)}$, but share the same recovery rate $\gamma$. In this model, each round has two steps: First, an individual is chosen u.a.r. and travels w.p. $p_{travel}$ to the other country. Afterwards, the process continues as before with the respective infection rates. Finally, using simulations, we characterise the influence of $p_{travel}$ on the total number of infections. Our simulations show that, depending on the $\beta^{(i)}$, increasing $p_{travel}$ can decrease or increase the expected total number of infections $\mathbf{E}\left[R_\infty\right]$.

Multi-agent consensus problems can often be seen as a sequence of autonomous and independent local choices between a finite set of decision options, with each local choice undertaken simultaneously, and with a shared goal of achieving a global consensus state. Being able to estimate probabilities for the different outcomes and to predict how long it takes for a consensus to be formed, if ever, are core issues for such protocols. Little attention has been given to protocols in which agents can remember past or outdated states. In this paper, we propose a framework to study what we call `memory consensus protocol'. We show that the employment of memory allows such processes to always converge, as well as, in some scenarios, such as cycles, converge faster. We provide a theoretical analysis of the probability of each option eventually winning such processes based on the initial opinions expressed by agents. Further, we perform experiments to investigate network topologies in which agents benefit from memory on the expected time needed for consensus.

We investigate the argumentation frameworks (AFs) that arise from multi-player transferable-utility cooperative games. These AFs have uncountably infinitely many arguments; arguments represent alternative payoff distributions to the players. We examine which of the various properties of AFs (from Dung's 1995 seminal paper) hold; we prove that these AFs are never finitary, never well-founded, always controversial and never limited controversial. We hope that this will encourage further exchange of ideas between argumentation and cooperative games.