Computing the Hessenberg matrix associated with a self-similar measure

We introduce in this paper a method to calculate the Hessenberg matrix of a sum of measures from the Hessenberg matrices of the component measures. Our method extends the spectral techniques used by G. Mantica to calculate the Jacobi matrix associated with a sum of measures from the Jacobi matrices of each of the measures. We apply this method to approximate the Hessenberg matrix associated with a self-similar measure and compare it with the result obtained by a former method for self-similar measures which uses a fixed point theorem for moment matrices. Results are given for a series of classical examples of self-similar measures. Finally, we also apply the method introduced in this paper to some examples of sums of (not self-similar) measures obtaining the exact value of the sections of the Hessenberg matrix

La marca de 'vulgar' en el DRAE: de Autoridades a 1992

Tradicionalment els diccionaris han recollit una sèrie de comentaris referents a l'ús i, alhora, s'han mostrat reticents a admetre tot un conjunt de paraules considerades 'malsonants'. El present treball examina aquesta qüestió en el Diccionario de la Lengua Española, de la Real Academia, en dues vessants: el desenvolupament de la marca de vulgar des del Diccionario de Autoridades (1726-1739) fins a l'última edició (1992), i l'estat d'aquesta marca en l'actualitat. S'han d'assenyalar unes edicions fonamentals, en aquest desenvolupament, a més de Autoridades: l'edició de 1780, primera en un volum, on les marques es codifiquen per mitjà d'abreviatures; la de 1817, on s'elimina la marca de 'vulgar'; la de 1925, on es restitueix aquesta marca; i les últimes edicions, amb una més gran incorporació d'aquest lèxic, fins arribar a les 269 accepcions de l'edició de 1992. Les marques de 'vulgar' es poden caracteritzar en tres grups: aquelles que designen conceptes objecte de tabú, aquelles que pertanyen al lèxic de grups marginals i arcaismes vigents a zones rurals. El resultat és un conjunt heterogeni, producte de la reconeguda dificultat per establir un sistema de marques lexicogràficament acceptable. L'alternativa ha de ser una simplificació del sistema de marques i una més gran fonamentació sociolingüística.Traditionally dictionaries have recorded a series of comments on usage and at the same time have been unwilling to accept a whole range of words considered to be 'offensive'. This study undertakes a twofold examination of this question in the Diccionario de la Lengua Española of the Real Academia: the development of the label 'vulgar' from the Diccionario de Autoridades (1726-1739) to the latest edition (1992) and the present day state of such labelling. Autoridades aside, certain editions which are fundamental to this development should be mentioned: the first single volume edition in 1780, in which the labels are codified by means of abbreviations; the 1817 edition in which the 'vulgar' entries are excluded; the 1925 edition which reinstated this entry type; and the more recent editions which include a wider range of this type of lexis, accepting up to 269 meanings in the 1992 edition. Words labelled as 'vulgar' can be classified in three groups: those that refer to taboo concepts, those that belong to the lexis of marginal groups, and archaisms that still prevail in rural areas. The result is a heterogeneous block, a product of the recognised difficulty to establish a labelling system that is lexicographically acceptable. The alternative must be a simplification of the labelling system and a greater sociolinguistics base

Pseudoscalar mixing in J/psi and psi(2S) decay

Based on the branching fractions of J/psi(psi(2S))-> VP from different collaborations, the pseudoscalar mixing is extensively discussed with a well established phenomenological model. The mixing angle is determined to be -14 degree by fitting to the new world average if only quark content is considered. After taking into account the gluonic content in eta and eta prime simultaneously, the investigation shows that eta favors only consisting of light quarks, while the gluonic content of eta prime is Z_{eta prime}^2=0.30\pm0.24.Comment: 8 page

Runaway electrification of friable self-replicating granular matter

We establish that the nonlinear dynamics of collisions between particles favors the charging of a insulating, friable, self-replicating granular material that undergoes nucleation, growth, and fission processes; we demonstrate with a minimal dynamical model that secondary nucleation produces a positive feedback in an electrification mechanism that leads to runaway charging. We discuss ice as an example of such a self-replicating granular material: We confirm with laboratory experiments in which we grow ice from the vapor phase in situ within an environmental scanning electron microscope that charging causes fast-growing and easily breakable palm-like structures to form, which when broken off may form secondary nuclei. We propose that thunderstorms, both terrestrial and on other planets, and lightning in the solar nebula are instances of such runaway charging arising from this nonlinear dynamics in self-replicating granular matter

Digital Topology Java Applet

We present here a java applet, accessible through the World Wide Web, which allows to apply to a binary digital image a series of topological algorithms for image processing

Supporting self-evaluation for children with mental disabilities through Augmented Reality

Proceedings of the 18th ACM International Conference on Interaction Design and Children, Boise© Association for Computing Machinery 2019. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in {SourcePublication}, https://doi.org/10.1145/3311927.3325307Self-evaluation is the ability to assess one's work, and is a key element in the psycho-pedagogical development of children with special needs in their path towards autonomy and self-determination. Acquiring this skill requires explicit training and materials, and it is often cumbersome and time-consuming. In this paper we present a study to ascertain to what extent systems based on Augmented Reality (AR) are a suitable and less expensive alternative to help children with cognitive disabilities to train self-evaluation skills in special education schools. For this purpose, we have developed tablet application (BART) that offers assistance to children with special needs to self-evaluate basic arithmetic operations. The system was designed through the involvement of 2 educators, 2 experts on psycho-pedagogy, and 2 software designers. The contribution of this paper is the description of BART, an innovative system for children with special needs and a concrete plan for an empirical study that is to be carried out on a short-term basis. Here we describe the methodology that is to be applied to the proposed study and outline the main expectations about the results and their implications in the issue of self-evaluation skills acquisition for children in special education

Benchmarking clear-sky reflectances

Accurate calculations of shortwave reflectances in clear-sky aerosol-laden atmospheres are necessary for various applications in atmospheric sciences. However, computational cost becomes increasingly important for some applications such as data assimilation of top-of-atmosphere reflectances in models of atmospheric composition. This study aims to provide a benchmark that can help in assessing these two requirements in combination. We describe a protocol and input data for 44 080 cases involving various solar and viewing geometries, four different surfaces (one oceanic bidirectional reflectance function and three albedo values for a Lambertian surface), eight aerosol optical depths, five wavelengths, and four aerosol types. We first consider two models relying on the discrete ordinate method: VLIDORT (in vector and scalar configurations) and DISORT (scalar configuration only). We use VLIDORT in its vector configuration as a reference model and quantify the loss of accuracy due to (i) neglecting the effect of polarization in DISORT and VLIDORT (scalar) models and (ii) decreasing the number of streams in DISORT. We further test two other models: the 6SV2 model, relying on the successive orders of scattering method, and Forward-Lobe Two-Stream Radiance Model (FLOTSAM), a new model under development by two of the authors. Typical mean fractional errors of 2.8 % and 2.4 % for 6SV2 and FLOTSAM are found, respectively. Computational cost depends on the input parameters but also on the code implementation and application as some models solve the radiative transfer equations for a range of geometries while others do not. All necessary input and output data are provided as a Supplement as a potential resource for interested developers and users of radiative transfer models