Continuous cellular automata on irregular tessellations : mimicking steady-state heat flow

Leaving a few exceptions aside, cellular automata (CA) and the intimately related coupled-map lattices (CML), commonly known as continuous cellular automata (CCA), as well as models that are based upon one of these paradigms, employ a regular tessellation of an Euclidean space in spite of the various drawbacks this kind of tessellation entails such as its inability to cover surfaces with an intricate geometry, or the anisotropy it causes in the simulation results. Recently, a CCA-based model describing steady-state heat flow has been proposed as an alternative to Laplace's equation that is, among other things, commonly used to describe this process, yet, also this model suffers from the aforementioned drawbacks since it is based on the classical CCA paradigm. To overcome these problems, we first conceive CCA on irregular tessellations of an Euclidean space after which we show how the presented approach allows a straightforward simulation of steady-state heat flow on surfaces with an intricate geometry, and, as such, constitutes an full-fledged alternative for the commonly used and easy-to-implement finite difference method, and the more intricate finite element method

Tracking uncertainty in a spatially explicit susceptible-infected epidemic model

In this paper we conceive an interval-valued continuous cellular automaton for describing the spatio-temporal dynamics of an epidemic, in which the magnitude of the initial outbreak and/or the epidemic properties are only imprecisely known. In contrast to well-established approaches that rely on probability distributions for keeping track of the uncertainty in spatio-temporal models, we resort to an interval representation of uncertainty. Such an approach lowers the amount of computing power that is needed to run model simulations, and reduces the need for data that are indispensable for constructing the probability distributions upon which other paradigms are based

The Tension Between Privacy and Security

A Review of President’s Review Group on Intelligence and Communications Technologies, Liberty and Security in a Changing World, 2013 and United Nations Office of the High Commissioner, Report of the Special Rapporteur on the Right to Privacy, Joseph A. Cannataci, 2016

A threshold for majority in the context of aggregating partial order relations

We consider a voting problem where voters have expressed their preferences on a single set of objects. These preferences take the shape of strict partial order relations. In order to allow extraction of a unique strict partial order relation corresponding to a social set of preferences, we determine the minimum number of votes a pairwise preference should receive in order to qualify as a social pairwise preference. Transitive closure of the social pairwise preferences will result in the social set of preferences. At the same time, the social set of preferences needs to be cycle-free, and the minimum number of votes should be determined with this constraint in mind. We provide an example application

Review and classification of fretting fatigue test rigs

There is no standard or generally accepted test rig for fretting fatigue experiments. Therefore, researchers adopt an existing concept, or build a new test rig that meets their specific requirements. However, too many different test rigs may be disadvantageous because the results of two different test rigs are hard to compare. The increasing amount of diversity is mainly caused by the lack of a recent literature survey on fretting fatigue test rigs. In 1994, Hills and Nowell described a few test rigs in Mechanics Of Fretting Fatigue. In this study, the authors made a classification of test rigs based on the contact geometry, which is determined by the test specimens, not by the test rig itself. The authors of this article present a review of the available literature, and present a classification based on the properties of test rigs. Fretting fatigue test rigs are first divided in two categories based on the geometry of the test specimen: full scale and coupon scale test rigs. The latter are mostly used to perform research and are subdivided in categories based on increasing functionalities. This is the ability to apply a fatigue load, a constant normal force, and an alternating slip in the range of some micrometers. In time, from the fifties until now, progress has been seen in the design of fretting fatigue test rigs. More parameters can be controlled during experiments and more measuring techniques are incorporated. State of the art test rigs are classified in the last category with mostffunctionalities, but still have imperfections. Future designers can use this article to classify their needs, or help to design a better test rig knowing the imperfections of the state of the art test rigs