In dielectric breakdown, the phenomena of streamers formation and spontaneous branching is commonly observed. A deterministic negative streamer model is reviewed in this article. We recently have proposed that this reduced model is able to explain the branching phenomena, due to a Laplacian instability quite like in viscous fingering. Particular attention is paid to the physical interpretation ...

Planning effective and well targeted actions to manage and improve the local and national healthcare services requires institutions to understand and analyse the real needs of the population based on reliable and timely statistical analysis on citizens’ health state. This is particularly important in developing countries in which healthcare facilities lack ICT infrastructures and network connec...

A physical model based on the mechanism observed in experimental investigations is introduced to describe the formation of negative leader steps. Starting with a small length of a space leader located at the periphery of the negative streamer system of the stepped leader the model simulates the growth and the subsequent formation of the leader step. Based on the model, the average step length, ...

For the purpose to facilitate development of high-speed Spindle Units (SUs) running on rolling bearings, we have developed a beam element model, algorithms, and software for computer analysis of thermal characteristics of SUs. The thermal model incorporates a model of heat generation in rolling bearings, a model of heat transfer from bearings, and models for estimation of temperature and temper...

Let F be an affine flat group scheme over a commutative ring R, and S an F -algebra (an R-algebra on which F acts). We define an equivariant analogue QF (S) of the total ring of fractions Q(S) of S. It is the largest F -algebra T such that S ⊂ T ⊂ Q(S), and S is an F -subalgebra of T . We study some basic properties. Utilizing this machinery, we give some new criteria for factoriality (UFD prop...

We prove a new lower bound on the critical density ρc of the hard disk model, i.e., the density below which it is possible to efficiently sample random configurations of n non-overlapping disks in a unit torus. We use a classic Markov chain which moves one disk at a time, but with an improved path coupling analysis. Our main tool is an optimized metric on neighboring pairs of configurations, i....