scholarly journals Zipf’s, Heaps’ and Taylor’s Laws are Determined by the Expansion into the Adjacent Possible

Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 752 ◽  
Author(s):  
Francesca Tria ◽  
Vittorio Loreto ◽  
Vito Servedio
Keyword(s):  
Ad Hoc ◽  
Ecological Systems ◽  
Dirichlet Processes ◽  
Urn Model ◽  
Modeling Framework ◽  
Self Consistent ◽  
Pólya’S Urn ◽  
Innovation Rate ◽  
Innovation Processes ◽  
Simple Modeling

Zipf’s, Heaps’ and Taylor’s laws are ubiquitous in many different systems where innovation processes are at play. Together, they represent a compelling set of stylized facts regarding the overall statistics, the innovation rate and the scaling of fluctuations for systems as diverse as written texts and cities, ecological systems and stock markets. Many modeling schemes have been proposed in literature to explain those laws, but only recently a modeling framework has been introduced that accounts for the emergence of those laws without deducing the emergence of one of the laws from the others or without ad hoc assumptions. This modeling framework is based on the concept of adjacent possible space and its key feature of being dynamically restructured while its boundaries get explored, i.e., conditional to the occurrence of novel events. Here, we illustrate this approach and show how this simple modeling framework, instantiated through a modified Pólya’s urn model, is able to reproduce Zipf’s, Heaps’ and Taylor’s laws within a unique self-consistent scheme. In addition, the same modeling scheme embraces other less common evolutionary laws (Hoppe’s model and Dirichlet processes) as particular cases.

scholarly journals Maximal Percentages in Pólya's Urn

2015 ◽  
Vol 52 (1) ◽  
pp. 180-190 ◽  
Author(s):  
Ernst Schulte-Geers ◽  
Wolfgang Stadje
Keyword(s):  
Positive Probability ◽  
Urn Model ◽  
Pólya’S Urn

We show that the supremum of the successive percentages of red balls in Pólya's urn model is almost surely rational, give the set of values that are taken with positive probability, and derive several exact distributional results for the all-time maximal percentage.

scholarly journals MINOT: Modeling the intracluster medium (non-)thermal content and observable prediction tools

2020 ◽  
Vol 644 ◽  
pp. A70
Author(s):  
R. Adam ◽  
H. Goksu ◽  
A. Leingärtner-Goth ◽  
S. Ettori ◽  
R. Gnatyk ◽  
...  
Keyword(s):  
Particle Physics ◽  
Computing Time ◽  
Cosmic Ray ◽  
High Energy ◽  
Intracluster Medium ◽  
Modeling Framework ◽  
X Ray ◽  
Prediction Tools ◽  
Self Consistent ◽  
Thermal Content

In the past decade, the observations of diffuse radio synchrotron emission toward galaxy clusters revealed cosmic-ray (CR) electrons and magnetic fields on megaparsec scales. However, their origin remains poorly understood to date, and several models have been discussed in the literature. CR protons are also expected to accumulate during the formation of clusters and probably contribute to the production of these high-energy electrons. In order to understand the physics of CRs in clusters, combining of observations at various wavelengths is particularly relevant. The exploitation of such data requires using a self-consistent approach including both the thermal and the nonthermal components, so that it is capable of predicting observables associated with the multiwavelength probes at play, in particular in the radio, millimeter, X-ray, and γ-ray bands. We develop and describe such a self-consistent modeling framework, called MINOT (modeling the intracluster medium (non-)thermal content and observable prediction tools) and make this tool available to the community. MINOT models the intracluster diffuse components of a cluster (thermal and nonthermal) as spherically symmetric. It therefore focuses on CRs associated with radio halos. The spectral properties of the cluster CRs are also modeled using various possible approaches. All the thermodynamic properties of a cluster can be computed self-consistently, and the particle physics interactions at play are processed using a framework based on the Naima software. The multiwavelength observables (spectra, profiles, flux, and images) are computed based on the relevant physical process, according to the cluster location (sky and redshift), and based on the sampling defined by the user. With a standard personal computer, the computing time for most cases is far shorter than one second and it can reach about one second for the most complex models. This makes MINOT suitable for instance for Monte Carlo analyses. We describe the implementation of MINOT and how to use it. We also discuss the different assumptions and approximations that are involved and provide various examples regarding the production of output products at different wavelengths. As an illustration, we model the clusters Abell 1795, Abell 2142, and Abell 2255 and compare the MINOT predictions to literature data. While MINOT was originally build to simulate and model data in the γ-ray band, it can be used to model the cluster thermal and nonthermal physical processes for a wide variety of datasets in the radio, millimeter, X-ray, and γ-ray bands, as well as the neutrino emission.

scholarly journals Word-formational productivity of the Slovene language in the case of sports neologisms

Linguistica ◽  
2011 ◽  
Vol 51 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Irena Stramljič Breznik ◽  
Ines Voršič
Keyword(s):  
Ad Hoc ◽  
Low Frequency ◽  
Creative Potential ◽  
Dynamic Nature ◽  
Foreign Word ◽  
Slovene Language ◽  
Lexical Processes ◽  
Innovation Processes

Newly created words are a frequent topic of research in modern linguistics. The reason for this is that innovation processes in lexicon are a reflection of dynamic tendencies which occur as a consequence of modern communication requirements. This contribution focuses on the field of sports, using a corpus approach based on the Sketch Engine (SkE). It investigates formations in Slovene with low frequency (e.g. nogometoljubec, karatejka, sankijada). Based on their morphemic structure, it determines whether they are potential neologisms, which are created according to a productive pattern, or nonce formations, which are created according to individual patterns connected with specific text usage, and which as ad-hoc formations do not belong to the productive word-formational patterns. In light of these findings, the question of the combinations of domestic and foreign word-formational elements will be discussed, and consequently also the question of the hybridization of Slovene formations today. The corpus-based approach will enable us to determine whether the analysed material represents a word-formational core or periphery of the lexicon. In order to detect new lexical processes, it is necessary to investigate atypical word-formational processes which open up the creative potential of language. They testify to the dynamic nature of language and to its capability to respond to the different needs of different users in different circumstances.

scholarly journals Uso didáctico de las TIC en los colegios rurales agrupados de la Región de Murcia

2018 ◽  
pp. 102-115
Author(s):  
María Pilar Segura García ◽  
Isabel María Solano Fernández ◽  
María Del Mar Sánchez Vera
Keyword(s):  
Information And Communication Technologies ◽  
Rural Schools ◽  
Ad Hoc ◽  
Educational Innovation ◽  
Communication Technologies ◽  
Descriptive Study ◽  
Key Factor ◽  
Innovación Educativa ◽  
Information And Communication ◽  
Innovation Processes

Actualmente, vivimos en una sociedad cada vez más digital, donde las Tecnologías de la Información y la Comunicación (TIC) están provocando un impacto en todos los niveles, también en el educativo. La escuela debe asumir el reto de integrar eficazmente las TIC, promoviendo situaciones enriquecidas con tecnologías en las que la metodología constituya el factor clave de los procesos de innovación educativa. La escuela rural debe hacer frente para ello a las desigualdades existentes, con el firme propósito de superarlas. Desde esta perspectiva, el artículo presenta un estudio descriptivo del uso que en las escuelas rurales de la Región de Murcia se hace de las TIC. La metodología escogida es la mixta, y la recogida de información se ha realizado a través de un cuestionario ad hoc construido para la investigación. Con los resultados obtenidos, hemos podido conocer las necesidades en la disponibilidad de recursos, y el uso didáctico que hacen de las TIC los docentes de los colegios rurales agrupados (CRA) en la Región de Murcia, constatando que aún les cuesta dejar atrás metodologías tradicionales para dar paso a la innovación educativa, a través de tecnologías emergentes. Today, we live in an increasingly digital society, where Information and Communication Technologies (ICT) are causing an impact at all ranges, in the educative even. The school must take on the challenge of effectively integrating ICT, promoting situations enriched with technologies in which methodology was the key factor in educational innovation processes. Rural schools must take up this challenge, assuming existing inequalities, but with the firm intention of overcoming them. From this perspective, the article presents a descriptive study of the use of ICT in rural schools in the Region of Murcia. The methodology chosen is mixed, and the collection of information has been carried out through an ad hoc questionnaire constructed for research. From the analysis of data, we have been able to know the needs in the availability of resources, and the didactic use that the teachers of the rural schools grouped together in the Region of Murcia make of the ICT, confirming that it is still difficult for them to leave behind traditional methodologies to give way to the educational innovation, through emerging technologies.

scholarly journals Maximal Percentages in Pólya's Urn

2015 ◽  
Vol 52 (01) ◽  
pp. 180-190 ◽  
Author(s):  
Ernst Schulte-Geers ◽  
Wolfgang Stadje
Keyword(s):  
Positive Probability ◽  
Urn Model ◽  
Pólya’S Urn

We show that the supremum of the successive percentages of red balls in Pólya's urn model is almost surely rational, give the set of values that are taken with positive probability, and derive several exact distributional results for the all-time maximal percentage.

scholarly journals On a preferential attachment and generalized Pólya’s urn model

2013 ◽  
Vol 23 (3) ◽  
pp. 1219-1253 ◽  
Author(s):  
Andrea Collevecchio ◽  
Codina Cotar ◽  
Marco LiCalzi
Keyword(s):  
Preferential Attachment ◽  
Urn Model ◽  
Pólya’S Urn

scholarly journals Planetary nebula abundance determinations: A view from 1D-RHD simulations

2011 ◽  
Vol 7 (S283) ◽  
pp. 398-399
Author(s):  
Ralf Jacob ◽  
Christer Sandin ◽  
Detlef Schönberner ◽  
Matthias Steffen
Keyword(s):  
Chemical Composition ◽  
Stellar Evolution ◽  
Plasma Diagnostics ◽  
Planetary Nebula ◽  
Ad Hoc ◽  
Radiation Hydrodynamics ◽  
Self Consistent ◽  
Formation And Evolution ◽  
Determination Methods ◽  
Abundance Determination

AbstractIn the last years (metallicity-dependent) radiation-hydrodynamics simulations have become a powerful tool to understand the formation and evolution of PNe in terms of simple morphologies and kinematics. Contrary to photoionization models, with their ad-hoc assumptions on structure and physics, the RHD models are self-consistent with respect to their density distribution, velocity field, chemical composition, and stellar evolution. We use our models as simple proxies for real PNe and investigate the reliability of common abundance determination methods, which are based on either plasma diagnostics or static photoionization (PI) models.

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