scholarly journals Atomic Cascade Computations

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 520
Author(s):  
Stephan Fritzsche ◽  
Patrick Palmeri ◽  
Stefan Schippers

Atomic cascades are ubiquitous in nature and they have been explored within very different scenarios, from precision measurements to the modeling of astrophysical spectra, and up to the radiation damage in biological matter. However, up to the present, a quantitative analysis of these cascades often failed because of their inherent complexity. Apart from utilizing the rotational symmetry of atoms and a proper distinction of different physical schemes, a hierarchy of useful approaches is therefore needed in order to keep cascade computations feasible. We here suggest a classification of atomic cascades and demonstrate how they can be modeled within the framework of the Jena Atomic Calculator. As an example, we shall compute within a configuration-average approach the stepwise decay cascade of atomic magnesium, following a 1s inner-shell ionization, and simulate the corresponding (final) ion distribution. Our classification of physical scenarios (schemes) and the hierarchy of computational approaches are both flexible to further refinements as well as to complex shell structures of the atoms and ions, for which the excitation and decay dynamics need to be modeled in good detail.

2020 ◽  
Vol 22 (1) ◽  
pp. 81-85 ◽  

The Research Domain Criteria (RDoC) project constitutes a translational framework for psychopathology research, initiated by the National Institute of Mental Health in an attempt to provide new avenues for research to circumvent problems emerging from the use of symptom-based diagnostic categories in diagnosing disorders. The RDoC alternative is a focus on psychopathology based on dimensions simultaneously defined by observable behavior (including quantitative measures of cognitive or affective behavior) and neurobiological measures. Key features of the RDoC framework include an emphasis on functional dimensions that range from normal to abnormal, integration of multiple measures in study designs (which can foster computational approaches), and high priority on studies of neurodevelopment and environmental influences (and their interaction) that can contribute to advances in understanding the etiology of disorders throughout the lifespan. The paper highlights key implications for ways in which RDoC can contribute to future ideas about classification, as well as some of the considerations involved in translating basic behavioral and neuroscience data to psychopathology.


Author(s):  
Boris Edgar Moafo Wembe ◽  
Olivier Cots ◽  
Bernard Bonnard

Helhmoltz-Kirchhoff equations of motions of vortices of an incompressible fluid in the plane define a dynamics with singularities and this leads to a Zermelo navigation problem describing the ship travel in such a field where the control is the heading angle. Considering one vortex, we define a time minimization problem, geometric frame being the extension of Randers metrics in the punctured plane, with rotational symmetry. Candidates as minimizers are parameterized thanks to the Pontryagin Maximum Principle as extremal solutions of a Hamiltonian vector field. We analyze the time minimal solution to transfer the ship between two points where during the transfer the ship can be either in a strong current region in the vicinity of the vortex or in a weak current region. Analysis is based on a micro-local classification of the extremals using mainly the integrability properties of the dynamics due to the rotational symmetry. The discussion is complex and related to the existence of an isolated extremal (Reeb) circle due to the vortex singularity. Explicit computation of cut points where the extremal curves cease to be optimal is given and the spheres are described in the case where at the initial point the current is weak.


2018 ◽  
Vol 6 ◽  
pp. 829-835
Author(s):  
Giedrė Valūnaitė-Oleškevičienė ◽  
Ramunė Eugenija Tovstucha ◽  
Liudmila Mockienė ◽  
Jelena Suchanova ◽  
Andrius Puksas

The aim of this study is to analyse the translation strategies of culture-specific items used in the Lithuanian translation of F. Scott Fitzgerald’s novel The Great Gatsby, published in 2013 by seeking to determine strategies chosen by the Lithuanian translator in order to eliminate cultural gaps related to culture-specific items, as well as to determine which of the strategies are predominant and therefore which translation approach prevails. The research is carried out relying on the classification of translation startegies provided by Pedersen (2005) which include strategies such as official equivalent, retention, specification, direct translation, generalization, substitution, and omission. Quantitative analysis is used to determine which strategies are predominant in the translation, while qualitative analysis is employed to discuss the reasonability of translator’s choices. Knowledge and awareness of the translation strategies of culture-specific items provide easily identifiable advice on how culture-specific items could be used and translated.


Author(s):  
Martin Fleischmann ◽  
Ombretta Romice ◽  
Sergio Porta

Unprecedented urbanisation processes characterise the Great Acceleration, urging urban researchers to make sense of data analysis in support of evidence-based and large-scale decision-making. Urban morphologists are no exception since the impact of urban form on fundamental natural and social patterns (equity, prosperity and resource consumption’s efficiency) is now fully acknowledged. However, urban morphology is still far from offering a comprehensive and reliable framework for quantitative analysis. Despite remarkable progress since its emergence in the late 1950s, the discipline still exhibits significant terminological inconsistencies with regards to the definition of the fundamental components of urban form, which prevents the establishment of objective models for measuring it. In this article, we present a study of existing methods for measuring urban form, with a focus on terminological inconsistencies, and propose a systematic and comprehensive framework to classify urban form characters, where ‘urban form character’ stands for a characteristic (or feature) of one kind of urban form that distinguishes it from another kind. In particular, we introduce the Index of Elements that allows for a univocal and non-interpretive description of urban form characters. Based on such Index of Elements, we develop a systematic classification of urban form according to six categories (dimension, shape, spatial distribution, intensity, connectivity and diversity) and three conceptual scales (small, medium, large) based on two definitions of scale (extent and grain). This framework is then applied to identify and organise the urban form characters adopted in available literature to date. The resulting classification of urban form characters reveals clear gaps in existing research, in particular, in relation to the spatial distribution and diversity characters. The proposed framework reduces the current inconsistencies of urban morphology research, paving the way to enhanced methods of urban form systematic and quantitative analysis at a global scale.


Epilepsia ◽  
2019 ◽  
Vol 60 (11) ◽  
pp. 2194-2203
Author(s):  
◽  
Bassel Abou‐Khalil ◽  
Zaid Afawi ◽  
Andrew S. Allen ◽  
Jocelyn F. Bautista ◽  
...  

PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0228132
Author(s):  
Ming-Jer Jeng ◽  
Mukta Sharma ◽  
Ting-Yu Chao ◽  
Ying-Chang Li ◽  
Shiang-Fu Huang ◽  
...  

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