727 research outputs found
Some remarks on modified power entropy
The aim of this note is to point out some observations concerning modified
power entropy of - and -actions. First, we provide an elementary
example showing that this quantity is sensitive to transient dynamics, and
therefore does not satisfy a variational principle. Further, we show that
modified power entropy is not suitable to detect the break of equicontinuity
which takes place during the transition from almost periodic to almost
automorphic minimal systems. In this respect, it differs from power entropy and
amorphic complexity, which are two further topological invariants for zero
entropy systems (`slow entropies'). Finally, we construct an example of an
irregular Toeplitz flow with zero modified power entropy.Comment: 17 pages, to appear in AMS Contemporary Mathematics serie
Miocene tectonics of the Maramures area (Northern Romania): implications for the Mid-Hungarian fault zone
The interplay between the emplacement of crustal blocks (e.g. "ALCAPAâ, "Tiszaâ, "Daciaâ) and subduction retreat is a key issue for understanding the Miocene tectonic history of the Carpathians. Coeval thrusting and basin formation is linked by transfer zones, such as the Mid-Hungarian fault zone, which seperates ALCAPA from Tisza-Dacia. The presented study provides new kinematic data from this transfer zone. Early Burdigalian (20.5 to âŒ18.5Ma) SE-directed thrusting of the easternmost tip of ALCAPA (Pienides), over Tisza-Dacia is linked to movements along the Mid-Hungarian fault zone and the Periadriatic line, accommodating the lateral extrusion of ALCAPA. Minor Late Burdigalian (âŒ18.5 to 16Ma) NE-SW extension is interpreted as related to back-arc extension. Post Burdigalian (post-16Ma) NE-SW shortening and NW-SE extension correlate with "soft collisionâ of Tisza-Dacia with the European foreland coupled with southward migration of active subduction. During this stage the Bogdan-Voda and Dragos-Voda faults were kinematically linked to the Mid-Hungarian fault zone. Sinistral transpression (16 to 12Ma) at the Bogdan-Voda fault was followed by sinistral transtension (12-10Ma) along the coupled Bogdan-Dragos-Voda fault system. During the transtensional stage left-lateral offset was reduced eastwards by SW trending normal faults, the fault system finally terminating in an extensional horse-tail spla
Alarm-Based Prescriptive Process Monitoring
Predictive process monitoring is concerned with the analysis of events
produced during the execution of a process in order to predict the future state
of ongoing cases thereof. Existing techniques in this field are able to
predict, at each step of a case, the likelihood that the case will end up in an
undesired outcome. These techniques, however, do not take into account what
process workers may do with the generated predictions in order to decrease the
likelihood of undesired outcomes. This paper proposes a framework for
prescriptive process monitoring, which extends predictive process monitoring
approaches with the concepts of alarms, interventions, compensations, and
mitigation effects. The framework incorporates a parameterized cost model to
assess the cost-benefit tradeoffs of applying prescriptive process monitoring
in a given setting. The paper also outlines an approach to optimize the
generation of alarms given a dataset and a set of cost model parameters. The
proposed approach is empirically evaluated using a range of real-life event
logs
Enantioselective reduction of sulfur-containing cyclic imines through biocatalysis
ZumbrÀgel N, Merten C, Huber SM, Gröger H. Enantioselective reduction of sulfur-containing cyclic imines through biocatalysis. Nature Communications. 2018;9(1): 1949
The timing of polyphase Miocene tectonics in Northern Romania
This study addresses the polyphase
Miocene tectonic evolution in the
Maramures area (northern Romania) by combining field observations,
stratigraphic arguments and
fission-track analysis (Tischler et al.
in press). Fission-track analysis has
been carried out on basement samples from the Rodna horst, situated
in the East Carpathians (Bucovinvian
nappes). This area was affected by Cretaceous
medium- to low-grade metamorphism,
followed by post-collisional exhumation
and renewed moderate thermal
overprint due to the deposition of
Eocene to Early Miocene sediments.
Based on paleostress analyses of mesoscale
structures, three main tectonic
phases can be disdinguished in the
study area, all of which are postdate
the earliest Miocene (Aquitanian,
20.5 Ma). In late Early Miocene
(Burdigalian) the Pienide nappes, nonmetamorphic
flysch series, were emplaced
onto the Paleogene to Early
Miocene sedimentary cover of the Bucovinian
nappes...conferenc
Linac Twins in Radiotherapy
In a radiotherapy department having more than one linear accelerator, it is rather common to match the dose output of all machines. In particular, the recently developed flattening filter free mode requires new investigations regarding the feasibility of matching and the consequences for quality assurance and workload. This refers also to the beam model of the radiotherapy treatment planning system. Our results show that matching is possible not only for flat beams but also for flattening filter free mode. Therefore, the machines can substitute each other in the case of breakdown or service without new treatment planning even in the case of complex intensity-modulated radiotherapy or volumetric-modulated arc therapy. The quality assurance is reduced to only one data set for both the linear accelerators and the radiotherapy treatment planning system
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