Spanish Treatises on Musica Practica c. 1480-1525: Reflections from a Cultural Perspective

Se estudian los tratados de música práctica ibéricos entre 1480-1535, atendiendo en primer lugar a la distribución y orden de los contenidos, y a las autoridades y ejemplos de composiciones mencionados. En segundo lugar, se realiza una comparación minuciosa de los textos de los tratados sobre los problemas de las mutaciones, conjuntas, disjuntas, y efectos de los modos. Se demuestra la persistencia de las tradiciones orales, puesto que algunas coincidencias se remiten a Fernando de Estevan (1410) y a Gil de Zamora (ca. 1265). Las novedades que aportó Ramos de Pareja respecto a los paralelismos entre la música mundana, humana e instrumental también son comentadas en relación a sus posibles fuentes. Se relacionan las prácticas de improvisación con las principales características diferenciadoras de la teoría musical hispánica, que ya identificara Robert Stevenson (1960: 67), por lo cual, por primera vez se intenta dar una explicación a estas peculiaridades. Por último, gracias a las conclusiones del estudio, se matiza la negación de Bonnie Blackburn (2001: 318) acerca de la presencia del humanismo en estos teóricos.Este trabajo forma parte del proyecto de investigación “La obra musical renacentista: fundamentos, repertorios y prácticas” HAR 2015-70181-P (MINECO/FEDER, UE

Digital marketing actions that achieve a better attraction and loyalty of users: an analytical study

Currently, the digital economy contributes decisively to an increase in competitiveness, especially as a digital transformation involves migrating to new technological models where digital marketing is a key part of growth and user loyalty strategies. Internet and Digital Marketing have become important factors in campaigns, which attract and retain Internet users. This study aims to identify the main ways in which users can be gained and retained by using Digital Marketing. The Delphi method with in-depth interviews was the methodology used in this study. The results of the research show the most important actions for achieving user recruitment and loyalty with Digital Marketing from the opinions of consulted experts. The limitations of this study are those related to the number of experts included in the study, and the number of research papers consulted in the literature review. The literature review and the results of this research are used to propose new solid research with a consolidated critical methodology. This research deals with a new approach that will optimize web technologies for the evolution of user trends, and therefore, will be of academic and professional use for marketing managers and web solution developers. The conclusions of the investigation show the key factors, discarding others that do not affect the optimization of conversions in B2C businesses such as the duration of the session and the rebound percentage. Likewise, the results of the research identify the specific actions that must be carried out to attract and retain users in B2C companies that use the Digital Marketing ecosystem on the Internet. The requirements for companies that wish to implement a model to optimize conversions using the current digital economy are also shown.info:eu-repo/semantics/publishedVersio

A Comparison of Machine-Learning Methods to Select Socioeconomic Indicators in Cultural Landscapes

Cultural landscapes are regarded to be complex socioecological systems that originated as a result of the interaction between humanity and nature across time. Cultural landscapes present complex-system properties, including nonlinear dynamics among their components. There is a close relationship between socioeconomy and landscape in cultural landscapes, so that changes in the socioeconomic dynamic have an effect on the structure and functionality of the landscape. Several numerical analyses have been carried out to study this relationship, with linear regression models being widely used. However, cultural landscapes comprise a considerable amount of elements and processes, whose interactions might not be properly captured by a linear model. In recent years, machine-learning techniques have increasingly been applied to the field of ecology to solve regression tasks. These techniques provide sound methods and algorithms for dealing with complex systems under uncertainty. The term ‘machine learning’ includes a wide variety of methods to learn models from data. In this paper, we study the relationship between socioeconomy and cultural landscape (in Andalusia, Spain) at two different spatial scales aiming at comparing different regression models from a predictive-accuracy point of view, including model trees and neural or Bayesian networks

An active attack on a distributed Group Key Exchange system

In this work, we introduce an active attack on a Group Key Exchange protocol by Burmester and Desmedt. The attacker obtains a copy of the shared key, which is created in a collaborative manner with the legal users in a communication group

Screening subclinical keratoconus with Placido-based corneal indices

Purpose: To assess in a sample of normal, keratoconic and keratoconus suspect eyes the performance of a set of new topographic indices computed directly from the digitized images of the Placido rings. Methods: This comparative study comprised a total of 124 eyes of 106 patients from the ophthalmic clinics Vissum Alicante and Vissum Almería (Spain), in three groups: control group (50 eyes), keratoconus group (50 eyes) and keratoconus suspect group (24 eyes). In all cases, a comprehensive examination was performed including the corneal topography with a Placido-based CSO topography system. Clinical outcomes were compared among groups, along with the discriminating performance of the proposed irregularity indices. Results: Significant differences at level 0.05 were found on the values of the indices among groups by means of Mann-Witney-Wilcoxon non-parametric test and Fisher’s exact test. Additional statistical methods, such as receiver operating characteristic analysis and K- fold cross-validation, confirmed the capability of the indices to discriminate between the three groups. Conclusions: Direct analysis of the digitized images of the Placido mires projected on the cornea is a valid and effective tool for detection of corneal irregularities. Although based only on the data from the anterior surface of the cornea, the new indices performed well even when applied to the keratoconus suspect eyes. They have the advantage of simplicity of calculation combined with high sensitivity in corneal irregularity detection, and thus can be used as supplementary criteria for diagnosing and grading keratoconus that can be added to the current keratometric classifications. Keywords: Corneal irregularities; subclinical keratoconus; irregularity index; diagnosis; corneal topography; Placido disk

Integrating network design and frequency setting in public transportation networks: a survey

This work reviews the literature on models which integrate the network design and the frequency setting phases in public transportation networks. These two phases determine to a large extent the service for the passengers and the operational costs for the operator of the system. The survey puts emphasis on modelling features, i.e., objective cost components and constraints, as well as on algorithmic aspects. Finally, it provides directions for further research.Peer Reviewe

Integrating network design and frequency setting in public transportation networks : a survey

This work reviews the literature on models which integrate the network design and the frequency setting phases in public transportation networks. These two phases determine to a large extent the service for the passengers and the operational costs for the operator of the system. The survey puts emphasis on modelling features, i.e., objective cost components and constraints, as well as on algorithmic aspects. Finally, it provides directions for further research

Optimal sampling patterns for Zernike polynomials

A pattern of interpolation nodes on the disk is studied, for which the inter- polation problem is theoretically unisolvent, and which renders a minimal numerical condition for the collocation matrix when the standard basis of Zernike polynomials is used. It is shown that these nodes have an excellent performance also from several alternative points of view, providing a numer- ically stable surface reconstruction, starting from both the elevation and the slope data. Sampling at these nodes allows for a more precise recovery of the coefficients in the Zernike expansion of a wavefront or of an optical surface. Keywords: Interpolation Numerical condition Zernike polynomials Lebesgue constant

Placido-based indices of corneal irregularity

Purpose: To construct a set of metrics computed from the raw keratoscopic data collected by any Placido corneal topographer. These indices that measure the irregularity of the anterior corneal surface are computed directly from the image of the mires reflected on the cornea, which is the most primary data possible. Besides the high sensitivity and specificity, this approach allows bypassing the surface or curvature reconstruction step that is currently performed by the software of any commercial Placido topographer. Methods: Several basic indices are proposed in order to detect irregularities on the anterior surface of the cornea, via analyzing some geometric and mathematical properties of the mires. These individual primary indices are built in a natural and intuitive way directly from the displacement of the digitized images of the rings reflected on the cornea. Additionally, compound indices are proposed (such as the generalized linear model or the classification trees) by combining some of the so-called primary indices to improve their efficiency. The computed metrics were developed and tested for the CSO topography system (CSO, Firenze,Italy), but the methodology proposed here extends easily to any other commercial Placido disks topographer. Results: The primary indices allow to discriminate, with excellent accuracy, between normal eyes and eyes with keratoconic corneas. Sensitivity and specificity of the primary indices is analyzed by using the ROC (receiver operating characteristic) curve methodology. Some combined indices are presented, and raise the efficiency to optimal. Conclusions: All the primary indices proposed exhibit very good performance at discriminating between normal and irregular corneas. The combined indices accuracy is optimal, so avoiding their use in clinical practice as corneal markers of disease. All these indices are fast to compute and can be easily implemented in any corneal topography system. Keywords: Corneal irregularities keratoconus irregularity index diagnosis corneal topography Placido disk