Maintenance optimization of a production system with buffercapacity

Marketing;Optimization;produktieleer/ produktieplanning

A Markov model for opportunity maintenance

Maintenance;produktieleer/ produktieplanning

Faults Self-Organized by Repeated Earthquakes in a Quasi-Static Antiplane Crack Model

We study a 2D quasi-static discrete {\it crack} anti-plane model of a tectonic plate with long range elastic forces and quenched disorder. The plate is driven at its border and the load is transfered to all elements through elastic forces. This model can be considered as belonging to the class of self-organized models which may exhibit spontaneous criticality, with four additional ingredients compared to sandpile models, namely quenched disorder, boundary driving, long range forces and fast time crack rules. In this ''crack'' model, as in the ''dislocation'' version previously studied, we find that the occurrence of repeated earthquakes organizes the activity on well-defined fault-like structures. In contrast with the ''dislocation'' model, after a transient, the time evolution becomes periodic with run-aways ending each cycle. This stems from the ''crack'' stress transfer rule preventing criticality to organize in favor of cyclic behavior. For sufficiently large disorder and weak stress drop, these large events are preceded by a complex space-time history of foreshock activity, characterized by a Gutenberg-Richter power law distribution with universal exponent $B=1 \pm 0.05$. This is similar to a power law distribution of small nucleating droplets before the nucleation of the macroscopic phase in a first-order phase transition. For large disorder and large stress drop, and for certain specific initial disorder configurations, the stress field becomes frustrated in fast time : out-of-plane deformations (thrust and normal faulting) and/or a genuine dynamics must be introduced to resolve this frustration

The hybrid financial instruments : the effects of the OECD BEPS Action 2 report and the ATAD

This contribution critically assesses the complex hybrid mismatch rule concerning financial instruments as developed under the OECD BEPS action 2-proposal and subsequently implemented in the Anti-Tax Avoidance Directive (ATAD). Both approaches are compared, starting with a profound analysis of the OECD initiative. Given their obligation to implement the European initiative in domestic tax law by 1 January 2020, domestic legislators now have to deal with the exact meaning of the Directive. However, the ambiguous text incites uncertainties and will definitely raise incoherencies between the several EU-Member States. Both international initiatives clearly rather aim to counter tax avoidance, instead of creating coherencies: only double non-taxation is envisaged and the taxpayer is confronted with a rather technical, hierarchical set of rules increasing his tax burden, because of an objective incoherent outcome. The solution is hardly inspired by the fundamental idea of BEPS to tax income where it has been generated. Given this rather mechanical approach the question is finally raised whether restrictions on the freedom of establishment and the free movement of capital can be justified. However, as this article focuses on the task for domestic legislators, this ultimate question has not been substantially investigated

Autism spectrum traits in normal individuals : a preliminary VBM analysis

In light of the new DSM-5 autism spectrum disorders diagnosis in which the autism spectrum reflects a group of neurodevelopmental disorders existing on a continuum from mild to severe expression of autistic traits, and recent empirical findings showing a continuous distribution of autistic traits in the general population, our voxel based morphometry study compares normal individuals with high autistic traits to normal individuals with low autistic traits. We hypothesize that normal individuals with high autistic traits in terms of empathizing and systemizing [high systemizing (HS)/low empathizing (LE)] share brain irregularities with individuals that fall within the clinical autism spectrum disorder. We find differences in several social brain network areas between our groups. Specifically, we find increased gray matter (GM) volume in the orbitofrontal cortex, the cuneus, the hippocampus and parahippocampus and reduced GM volume in the inferior temporal cortex, the insula, and the amygdala in our HS/LE individuals relative to our HE/LS (low autistic traits in terms of empathizing and systemizing) individuals

Unbalanced instabilities of rapidly rotating stratified shear flows

The linear stability of a rotating, stratified, inviscid horizontal plane Couette flow in a channel is studied in the limit of strong rotation and stratification. An energy argument is used to show that unstable perturbations must have large wavenumbers. This motivates the use of a WKB-approach which, in the first instance, provides an approximation for the dispersion relation of the various waves that can propagate in the flow. These are Kelvin waves, trapped near the channel walls, and inertia-gravity waves with or without turning points. Although, the wave phase speeds are found to be real to all algebraic orders in the Rossby number, we establish that the flow, whether cyclonic or anticyclonic, is unconditionally unstable. This is the result of linear resonances between waves with oppositely signed wave momenta. We derive asymptotic estimates for the instability growth rates, which are exponentially small in the Rossby number, and confirm them by numerical computations. Our results, which extend those of Kushner et al (1998) and Yavneh et al (2001), highlight the limitations of the so-called balanced models, widely used in geophysical fluid dynamics, which filter out Kelvin and inertia-gravity waves and hence predict the stability of the Couette flow. They are also relevant to the stability of Taylor-Couette flows and of astrophysical accretion discs.Comment: 6 figure