428 research outputs found
Actions Speak Louder Than Goals: Valuing Player Actions in Soccer
Assessing the impact of the individual actions performed by soccer players
during games is a crucial aspect of the player recruitment process.
Unfortunately, most traditional metrics fall short in addressing this task as
they either focus on rare actions like shots and goals alone or fail to account
for the context in which the actions occurred. This paper introduces (1) a new
language for describing individual player actions on the pitch and (2) a
framework for valuing any type of player action based on its impact on the game
outcome while accounting for the context in which the action happened. By
aggregating soccer players' action values, their total offensive and defensive
contributions to their team can be quantified. We show how our approach
considers relevant contextual information that traditional player evaluation
metrics ignore and present a number of use cases related to scouting and
playing style characterization in the 2016/2017 and 2017/2018 seasons in
Europe's top competitions.Comment: Significant update of the paper. The same core idea, but with a
clearer methodology, applied on a different data set, and more extensive
experiments. 9 pages + 2 pages appendix. To be published at SIGKDD 201
Woordvorming tussen systeem en norm: affixoĂŻden in het Duits en in het Nederlands
Starting from observations from (Belgian-)Dutch usage, the present article offers a comparison of affixoids (better known in English as "semi-affixes") in German and Dutch. We begin with a discussion of recent developments in the affixoid debate with regard to both German and Dutch and then compare prefixoids and suffixoids in the two languages on the basis of corpus data. As it turns out, divergences between German and Dutch affixoids (though at times considerable) are not due to differences between the linguistic systems. Rather, they are associated exclusively with the level of norm, raising interesting questions as to potential determining factors and making a wider crosslinguistic comparison of affixoids (e.g. including Swedish) an even more promising proposition
New composition-dependent cooling and heating curves for galaxy evolution simulations
In this paper, we present a new calculation of composition-dependent radiative cooling and heating curves of low-density gas, intended primarily for use in numerical simulations of galaxy formation and evolution. These curves depend on only five parameters: temperature, density, redshift, [Fe/H] and [Mg/Fe]. They are easily tabulated and can be efficiently interpolated during a simulation. The ionization equilibrium of 14 key elements is determined for temperatures between 10 K and 10(9) K and densities up to 100 amu cm(-3) taking into account collisional and radiative ionization, by the cosmic UV background and an interstellar radiation field, and by charge-transfer reactions. These elements, ranging from H to Ni, are the ones most abundantly produced and/or released by SNIa, SNII and intermediate-mass stars. Self-shielding of the gas at high densities by neutral hydrogen is taken into account in an approximate way by exponentially suppressing the H-ionizing part of the cosmic UV background for H i densities above a threshold density of n(HI, crit) 0.007 cm(-3). We discuss how the ionization equilibrium, and the cooling and heating curves, depends on the physical properties of the gas. The main advantage of the work presented here is that, within the confines of a well-defined chemical evolution model and adopting the ionization equilibrium approximation, it provides accurate cooling and heating curves for a wide range of physical and chemical gas properties, including the effects of self-shielding. The latter is key to resolving the formation of cold, neutral, high-density clouds suitable for star formation in galaxy simulations
Modeling the recrystallization textures in particle containing al alloys after various rolling reductions
Various degrees of rolling reductions account for diverse recrystallization mechanisms and thus different microstructural and texture features. The development of deformation and recrystallization textures is discussed based on experimental data and results of finite element and crystal plasticity simulations. A recrystallization model is presented that incorporates the microstructural heterogeneities and changes in local stored energy. The experimental observations and results of crystal plasticity calculations testify that orientation selection during recrystallization is controlled by low stored energy nucleation which is incorporated in the recrystallization model. Results of texture simulations show that the evolution of {100} and {011} components is related to a particle stimulated nucleation mechanism
Analytic model for multi-point large-radius bending of steel sheets
While the majority of industrial sheet bending processes consist of conventional air bending, more complex bending processes such as multi-point bending are also utilized. Multi-point bending involves forming several bends simultaneously with changing contact conditions. Of the various models that may be employed to simulate such processes, analytic models are most attractive for industrial applications as they are time-efficient, strongly theoretically supported and easily extended to a wide range of dies layouts without the need of additional experimental data. In this paper a new analytic model is presented to predict the forming forces, the deformation of the sheet and the springback. The model is based on the literature around large-radius air bending. The geometry of the sheet is determined at each moment as a function of the tool’s positions. The reaction forces are calculated based on the equilibrium of forces and moments and the springback is calculated based on the elastic unloading of the internal bending forces. The model has been compared with a more time consuming finite element (FE) model and the geometry of the sheet has been experimentally verified by means of digital processing of video images. The proposed analytic model shows good agreement with the computational FE model and it is demonstrated to be a robust tool for calculation of the bending characteristics
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