Public Key Protocols over Twisted Dihedral Group Rings

Key management is a central problem in information security. The development of quantum computation could make the protocols we currently use unsecure. Because of that, new structures and hard problems are being proposed. In this work, we give a proposal for a key exchange in the context of NIST recommendations. Our protocol has a twisted group ring as setting, jointly with the so-called decomposition problem, and we provide a security and complexity analysis of the protocol. A computationally equivalent cryptosystem is also proposed

A framework for effective management of condition based maintenance programs in the context of industrial development of E-Maintenance strategies

CBM (Condition Based Maintenance) solutions are increasingly present in industrial systems due to two main circumstances: rapid evolution, without precedents, in the capture and analysis of data and significant cost reduction of supporting technologies. CBM programs in industrial systems can become extremely complex, especially when considering the effective introduction of new capabilities provided by PHM (Prognostics and Health Management) and E-maintenance disciplines. In this scenario, any CBM solution involves the management of numerous technical aspects, that the maintenance manager needs to understand, in order to be implemented properly and effectively, according to the company’s strategy. This paper provides a comprehensive representation of the key components of a generic CBM solution, this is presented using a framework or supporting structure for an effective management of the CBM programs. The concept “symptom of failure”, its corresponding analysis techniques (introduced by ISO 13379-1 and linked with RCM/FMEA analysis), and other international standard for CBM open-software application development (for instance, ISO 13374 and OSA-CBM), are used in the paper for the development of the framework. An original template has been developed, adopting the formal structure of RCM analysis templates, to integrate the information of the PHM techniques used to capture the failure mode behaviour and to manage maintenance. Finally, a case study describes the framework using the referred template.Gobierno de Andalucía P11-TEP-7303 M

Comparison of coal chars prepared in different devices at similar temperature

The characteristics of chars prepared in both a drop tube furnace (DTF) and a flat flame burner (FFB) at 1300 ºC from seven coals of different rank and maceral composition are the subject of this study. Coal samples sized and sieved to 36-75 μm were fed. The flame temperature of the FFB was achieved with a mixture of methane, air and oxygen whereas two different gas compositions were used in the DTF to account for sub-stoichiometric (2.5% O2) and close to stoichiometric (10% O2) oxygen levels. Determination of micropore surface area was carried out by CO2 adsorption isotherms at 0°C and char reactivity to air was measured at 550 °C in a thermogravimetric analyser (TGA). Overall similar combustion trends were obtained in both devices with burnout decreasing as coal rank increases and CO2 surface areas decreasing up to the medium volatile bituminous coal rank and increasing again for the anthracites. The results reveal a reasonable agreement between burnouts of FFB chars and low oxygen DTF chars whereas higher burnouts were obtained for higher oxygen DTF chars. The CO2 surface areas of the chars reasonably scattered without any systematic trend. The intrinsic reactivities of both series of chars from the DTF were similar to the corresponding FFB chars. Increasing coal rank, intrinsic reactivity of chars from the different combustion conditions decreased.The Principality of Asturias (Principado de Asturias), Project PC04-03 and the Ministry for Education (Ministerio de Educación), Project PSE2-2005Peer reviewe

Autonomy, Motivation, and Digital Pedagogy Are Key Factors in the Perceptions of Spanish Higher-Education Students toward Online Learning during the COVID-19 Pandemic

This paper proposes a development model of the adaptation capacity of students to digital transformation in university teaching through three constructs: motivations, digital pedagogy, and student autonomy. For this study, an ad hoc scale was created to record the adaptation capacity of students to digital transformation. The sample was 483 students from the University of Seville (Spain), to whom an online survey was administered during the development of online teaching in the period of November 2020 using the Google Forms platform. The findings of this study showed that university student motivation acquired a greater threshold than autonomy, whose threshold in turn, was greater than that of digital pedagogy in the ability to adapt to online teaching and that the capacity of adaptation to the online modality is explained by the perception that university students have of the usefulness, products, and learning outcomes, among others. In conclusion, the lack of adequate and enabled study spaces is key to developing the online model. We consider all these aspects as prospective research objectives

Mediterranean model of Pharmacy and the freedom of establishment in the European Union

El marco jurídico europeo relativo a oficinas de farmacia se encuentra en la Directivas de 1985 de armonización de las legislaciones nacionales que establecen las condiciones para el ejercicio profesional del farmacéutico. La reglamentación de la Unión Europea no recoge un criterio comunitario para la planificación farmacéutica. Las Directivas de armonización de las legislaciones nacionales de los Estados miembros reconocen la competencia estatal en materia de establecimiento farmacéutico. Estas premisas dan lugar a la existencia de diferencias entre las legislaciones nacionales respecto a los principios de limitación para el establecimiento. La Comisión de la UE se planteó la compatibilidad de estas legislaciones con el principio comunitario de libertad de establecimiento proclamado por el Tratado. El objetivo de esta comunicación es hacer un seguimiento en el procedimiento planteado contra España y analizar la adecuación de las legislaciones cuestionadas al derecho comunitario a la luz de la jurisprudencia del Tribunal de Justicia de la Unión Europea.The European legal framework relating to pharmacies located on the directives of 1985 on the harmonization of national laws which set conditions for professional pharmacists. The EU regulation does not include a community approach for pharmaceutical planning. Directives to harmonize national laws of Member States recognize the state competition in the field of pharmaceutical establishment. These assumptions lead to the existence of differences between national laws on the principles of limitation for the facility. The EU Commission considers the compatibility of these laws with the EU principle of freedom of establishment proclaimed by the Treaty. The purpose of this communication is to monitor the proceedings brought against Spain and to assess the adequacy of the laws challenged with Community law in light of the Court of Justice of the European Union

Implantación de un visor GIS con software libre en la Comunidad de Regantes del Trasvase Tajo-Segura de Totana, Murcia

En el ámbito del desarrollo de software orientado a la implementación de sistemas de información geográfica, una de las empresas de referencia a nivel internacional es la multinacional estadounidense Esri. En particular, en el contexto de los visores cartográficos para la web, por la experiencia del usuario que aportan. No obstante, la utilización de visores, tal y como los ofrece Esri en su sitio web, queda circunscrita al consumo de servicios ArcGIS Server, que sólo se pueden gestionar mediante la aplicación de Esri ArcGIS for Server. El elevado coste de la adquisición de este software propicia, en muchos casos, la búsqueda de soluciones alternativas, que casi siempre pasan por la utilización de librerías de desarrollo de código abierto, como son OpenLayers, GeoExt y ExtJS, entre otras. En este trabajo se plantea una propuesta que aprovecha las características funcionales del visor de Esri, evitando recurrir a ArcGIS for Server como servidor de mapas. Esto es posible gracias a la generación de servicios WMS y WFS a partir de software libre (servidores de mapas MapServer o GeoServer) y, al hecho de que Esri mantenga liberado bajo la licencia Apache 2.0 el código de su visor, permitiendo la alteración del código, lo que permite implementar capacidades funcionales nuevas, como la recuperación interactiva de datos temáticos (operación GetFeatureInfo en servicios WMS) y las búsquedas multicriterio sobre el mapa (operación GetFeature en servicios WFS). Este visor de La Compañía® ha sido implantado con éxito en la Comunidad de Regantes del Trasvase Tajo-Segura de Totana en Murcia, poniendo de manifiesto de que con software libre es posible construir visores con las mismas y/o mejores funcionalidades que los visores implementados con software propietario, y reforzar las ventajas en el ahorro de costes aplicando software libre, logrando con ello independencia tecnológica de las empresas que comercializan software propietario

Estudio del riesgo de erosión potencial en la cuenca alta del Río Hozgarganta

En el presente trabajo se analiza el riesgo de erosión potencial del suelo en la cuenca alta del río Hozgarganta. Para ello se ha utilizado el método propuesto por PAP/RAC (1997) y modificado posteriormente por Jordán y Martínez-Zavala (Jordán, 2000; Martínez-Zavala, 2001; Martínez-Zavala et al., 2002). Mediante este sistema se ha dividido el área de estudio en unidades de territorio con diferente grado de susceptibilidad a la erosión hídrica (estado erosivo). Se ha evaluado el riesgo de erosión actual y el riesgo de erosión potencial, planteando tres escenarios posibles de cobertura de la vegetación. De esta forma, se puede concluir que el riesgo de pérdida de suelo en la cuenca del Hozgarganta es bajo. Sin embargo, el sistema se halla en un equilibrio inestable, ya que pequeños cambios en la cobertura de la vegetación pueden originar grandes cambios en la intensidad de los procesos erosivos.Potential soil erosion risk in the high basin of Hozgarganta river is analyzed in this paper. We have used the methodology proposed by PAP/RAC (1997), as modified Jordán and Martínez-Zavala (Jordán, 2000; Martínez-Zavala, 2001; MartínezZavala et al., 2002). Using this method, the study area has been divided in terrain units with different level of susceptibility to rainfall-induced erosion risk (erosive status). An assesment of actual and potential erosion risk is carried out, suposing three posible situations, acording to different percentages of canopy. As a conclusion, the actual soil erosion risk is low for the Hozgarganta Basin. However, the equilibrium of the system is unstable, so that little changes in the vegetation cover may originate great changes in the intensity of the erosive processe

Guía de especies vegetales de la cuenca mediterránea aptas para revegetación: Adecuación para zonas degradadas y contaminadas

La guía contiene información de especies de plantas de la cuenca mediterránea, adecuadas para utilizar en revegetación de zonas degradadas y/o contaminadas con presencia de metales pesados, siguiendo diferentes criterios medioambientales y paisajísticos y estableciendo recomendaciones o restricciones para su implantación y crecimiento, sin necesidad de recurrir a la utilización de especies exóticas con potencial invasor. Para cada especie se proporciona información abreviada de las principales características que las hacen aptas para su uso en los diferentes entornos. Finalmente se establecen cinco modelos de asociaciones paisajísticas para usar en diferentes zonas y con diferentes condiciones medioambientales

Geographical Barriers Impeded the Spread of a Parasitic Chromosome

Parasitic supernumerary (B) chromosomes show high capability to spread across populations. But the existence of abrupt discontinuities in their distribution demands an explanation. The grasshopper Eyprepocnemis plorans plorans harbour supernumerary chromosomes in all natural populations hitherto analyzed from the Circum-Mediterranean region, with the single exception of the headwaters of the Iberian Segura River and several of its tributaries. To ascertain the causes of this distribution pattern, we analyze here the genetic structure of five natural populations collected in this zone (two +B and three -B), by means of ISSR markers. We found significant population structure, with two kinds of populations coinciding with +B and -B ones, separated by strong barriers to gene flow. This gives strong support to the hypothesis that the non-B populations precede B origin, and that B-carrying individuals from coastal zones have been able to colonize upstream areas, until geographical barriers (usually narrow canyons and arid areas surrounding them) impeded their advance.The authors received no specific funding for this work. Project applications have been rejected in 2012, 2013 and 2014

Evaluación de Impacto Ambiental: Aspectos teóricos

El libro recoge los fundamentos teóricos necesarios para la realización de una Evaluación de Impacto Ambienta