Validation of suply chain integration scales and the effect that size, level of vertical integration, industry and country have on their value

Academic literature would appear to indicate that supply chain integration is a major factor in explaining the performance of companies. The results are nevertheless inconclusive. Certain authors put forward the idea that the vast range of results obtained are due, amongst other things, to the fact that there is no exactness to the group of scales used, no-one has yet published an analysis of the measurement models nor clear benchmarks. In this paper, we present the theoretical definition of four supply chain integration scales (clients, suppliers, external and internal) and the convergent and discriminant validity of a measurement instrument based on a list of items taken from earlier papers. We also propose a benchmark to interpret the scales by percentiles, using a diverse international sampling broken down into sub-samples based on sector, type of company, size of company and degree of vertical integration.Ministerio de Ciencia e Innovación DPI2010-18243Ministerio de Educación y Ciencia DPI2006-0553

Stochastic resource allocation with a backhaul constraint for the uplink

We propose a novel stochastic radio resource alloca- tion strategy for the uplink that achieves long-term fairness in terms of similar bitrates considering backhaul and air-interface capacity limitations. We focus on a single cell scenario based on WCDMA technology. We propose to use a maximin criteria to introduce fairness among the different users’ throughputs. An stochastic approximation is implemented to obtain an online algorithm where the Lagrange multipliers are estimated at each scheduling period. Our results show that the proposed scheme achieves higher fairness among the users and, in some cases, a higher sum-rate compared with the well-known proportional fair scheduler.Postprint (author's final draft

La cartografía digital y los sistemas de información geográfica, a través de las publicaciones del Grupo de Didáctica de la AGE y la revista Didáctica Geográfica

En los últimos años han crecido las publicaciones dedicadas a la utilidad didáctica de la cartografía digital y los diferentes sistemas de información geográfica en el ámbito de la Geografía, sobre todo gracias al desarrollo de software libre y los recursos de Internet. En este trabajo se presenta un análisis de estos trabajos aparecidos en las publicaciones editadas por el grupo de trabajo de Didáctica de la Geografía de la AGE y la revista Didáctica Geográfica

The effect of the use of multimedia applications on the motivation of POM students

Students are not always motivated to learn and on occasion their goal is simply to pass examinations. The POM teacher must therefore attempt to increase student motivation for the study of POM. In our opinion, ICT (Information and Communication Technologies) -based teaching tools (e.g. multimedia training applications) boost interest and strengthen the motivation to learn to the extent they are adapted to the user’s needs and demonstrate the use and practical application of POM. With a view to contrasting this hypothesis we have conducted empirical research with Business Administration students at the University of Seville (Spain). The research compares two distance learning scenarios: a self-learning multimedia application (that we have designed as teaching material) and traditional written materials. In this paper, the effects on motivation are presented along with the students’ perception of the degree to which the method adapts to their needs

La enseñanza de la climatología en los manuales escolares de ciencias sociales en Educación Primaria

La enseñanza del clima y tiempo atmosférico está muy presente a lo largo de todo el sistema educativo de nuestro país, especialmente en las primeras etapas en las que los alumnos desarrollan habilidades para el conocimiento del espacio geográfico. Este trabajo analiza cuales son los contenidos enseñados sobre este tema, los recursos empleados y el tipo de actividades más habituales que aparecen en los diferentes libros de texto de Educación Primaria. El fin último, es conocer si se realiza un adecuado uso y tratamiento de la climatología en los manuales escolares, si permite la consecución de las competencias geográficas y si se adecúa al desarrollo psicoevolutivo del alumnado de Educación Primaria

A stochastic approach for resource allocation with backhaul and energy harvesting constraints

We propose a novel stochastic radio-resource-allocation strategy that achieves long-term fairness considering backhaul and air-interface capacity limitations. The base station (BS) is powered only with a finite battery that is recharged by an energy harvester. The energy harvesting is also taken into account in the proposed resource-allocation strategy. The constrained scenario is often found in remote rural areas where the backhaul connection is limited, and the BSs are fed with solar panels of reduced size. Our results show that the proposed scheme achieves higher fairness among the users and provides greater worst user rate and sum rate if an average backhaul constraint is considered.Peer ReviewedPostprint (published version

Un estudio sobre las escalas que definen la Gestión de la Calidad Total y los programas de alta implicación de los Recursos Humanos.

Los programas de gestión de recursos humanos (HRM) son un sistema formal de actividades usadas en la organización, que dan a los empleados las habilidades, información y motivación para intervenir en la toma de decisiones y, como resultado de ello, transforman la mano de obra en una fuente de ventaja competitiva sostenible, siempre y cuando se utilicen integrados con la estrategia de la empresa (Guerrero y Barraud-Didier, 2004; Guthrie et al., 2002; Mayson y Barrett, 2006; Wood y de Menezes, 2008; Zatzick y Iverson, 2006). Por otra parte, los programas de gestión total de la calidad (TQM) tienen por objetivo mejorar y mantener la calidad de los productos y procesos para cumplir y superar las expectativas de los clientes, aprovechando la implicación de los mandos, trabajadores, clientes y proveedores (Cua et al., 2001; Martinez-Costa y Jimenez-Jimenez, 2009; Ooi et al., 2007; Sila, 2007; Wood y de Menezes, 2008). Tanto HRM como TQM forman un sistema coherente de prácticas, consistente y reforzado, en el que el resultado global es superior a la aplicación aislada de alguna de ellas (Drummond y Stone, 2007; Shah y Ward, 2007

Ultra-dense energy storage utilizing high melting point metallic alloys and photovoltaic cells

A novel concept for energy storage utilizing high melting point metallic alloys and photovoltaic cells is presented. In the proposed system, the energy is stored in the form of latent heat of metallic alloys and converted to electricity upon demand by infrared sensitive photovoltaic cells. Silicon is considered in this paper due to its extremely high latent heat (1800 J/g), melting point (1410°C), low cost (�$1.7/kg) and abundance on earth. The proposed solution enables an enormous energy storage density of � 500 Wh/kg and � 1 MWh/m3, which is 12 times higher than that of lead-acid batteries, 4 times than that of Li-ion batteries and 10 to 20 times than that of the molten salts utilized in CSP systems