A novel low-voltage reconfigurable ΣΔ modulator for 4G wireless receivers

This paper presents a new adaptable cascade ΣΔ modulator architecture fo r low-voltage multi-stan- dard applications. It uses two reconfiguration strategies: a programmable global resonation and a variable loop-filter order. These techniques are properly com- bined in a novel topology that allows to increase the effec- tive resolution in a given bandwidth, whereas keeping relaxed output swing requirements and high robustness to mismatch and to non-linearities of the amplifiers. Time-domain simulations incl uding the main circuit-level non-idealities are shown to demonstrate the benefits of the presented modulator when it is configured to cope with the requirements of GSM, UMTS, WLAN and Wi-Max.España, Ministerio de Educación y Ciencia TEC2007-67247-C02-01/MICEspaña, Ministerio de Innovación, Ciencia y Empresa, Junta de Andalucía TIC-253

Why continue sharing: determinants of behavior in collaborative economy services

La economía colaborativa está revolucionando la forma en que los consumidores utilizan los bienes y servicios. En nuestro estudio modificamos y ampliamos el modelo de confirmación de expectativas para determinar los factores motivacionales que impulsan la satisfacción y la intención de continuar usando los servicios de viajes colaborativos. Más importante aún, agregamos el valor social como un factor adicional. En este estudio fueron encuestados usuarios españoles experimentados de BlaBlaCar. La calidad del servicio, la utilidad percibida, la confianza y el valor social son determinantes de la satisfacción de los usuarios experimentados y, a través de ella, de la intención de continuar usando; mientras que no es el caso para el impacto ambiental ni para los beneficios económicos. Además, la confianza afecta directamente a la intención de continuar. Estos resultados tienen implicaciones gerenciales relevantes, mostrando que los usuarios de algunos servicios colaborativos están motivados por otros factores además de los económicos.The sharing economy is revolutionizing the way consumers use goods and services. In our study we modify and extend the expectation confirmation model to determine the motivational factors which drive the satisfaction and continue intention to use ridesharing services. Most importantly, we add social value as an additional factor to those previously studied in the literature. We apply our model in a survey among experienced Spanish users of BlaBlaCar. Service quality, perceived usefulness, trust and social value are determinants of satisfaction of experienced users and through it, of intention to continuance; while it is the case neither for environmental impact nor for economic benefits. Additionally, trust affects directly continuance. These results have relevant managerial implications, showing that users of some sharing services are motivated by other factors than purely economic

Transforming rural education in Colombia through family participation: The case of school as a learning community

Purpose: This article studies the impact of the implementation of learning communities in a rural context of Colombia, specifically concerning the improvements related to learning and social cohesion. Design/methodology/approach: This longitudinal case study analyses the process and the impacts of the transformation of a school in 2015 and the subsequent years of 2016 and 2017. The data analysed include standardized external tests, a documentary analysis of the school and interviews with students, family members and the schoolteacher. Findings: The results obtained indicate academic improvement within the school with results that exceed the national average of Colombia. The results also report how violence has been reduced by 80%. All of these outcomes were motivated by the participation of the community in the school. Practical implications: The conclusions drawn are relevant as they show a success case that overcame the difficulties related to the lack of accessibility and quality of rural education in Colombia

Toughness of the corona of two graphs

The toughness of a non-complete graph G = (V , E) is defined as τ (G) = min{|S|/ω(G − S)}, where the minimum is taken over all cutsets S of vertices of G and ω(G − S) denotes the number of components of the resultant graph G − S by deletion of S. The corona of two graphs G and H , written as G ◦ H , is the graph obtained by taking one copy of G and |V (G)| copies of H , and then joining the ith vertex of G to every vertex in the ith copy of H . In this paper, we investigate the toughness of this kind of graphs and obtain the exact value for the corona of two graphs belonging to some families as paths, cycles, stars, wheels or complete graphs.Ministerio de Educación y Ciencia MTM2008-06620-C03-02Generalitat de Cataluña 1298 SGR2009Junta de Andalucía P06-FQM-0164

Un programa de intervención autoaplicado a través de Internet para el tratamiento de la depresión: Sonreír es divertido

Depression is among the world’s greatest contemporary health problems. It is necessary to have recourse to effective interventions to treat it. Although it is true that there are currently several psychological treatments for depression whose effectiveness is supported by empirical data, only a very limited segment of the population is able to benefit from them due to the high cost of their implementation, the amount of time required and the lack of well-trained professionals. The use of the Internet has been considered a useful tool to administer treatments and overcome the problems that arise. Thus, this paper aims to present a description of an online self-applied interven- tion program for the treatment of depression, developed by the Laboratorio de Psicología y Tecnología (Labpsitec).La depresión es una de las grandes problemáticas para la salud mundial en la actualidad. Es necesario entonces disponer de intervenciones eficaces para su tratamiento. Si bien en la actualidad existen numerosos tra- tamientos psicológicos con apoyo empírico sobre su eficacia, la población que se beneficia de los mismos es muy reducida, debido a los altos costes de su implementación, al tiempo requerido y a la falta de profesionales bien entrenados. El uso de Internet aparece como una herramienta útil para administrar los tratamientos y superar los problemas que se presentan. En este sentido, el presente trabajo tiene por objetivo presentar la descripción de un programa de intervención autoaplicado a través de Internet para el tratamiento de la depresión, desarrollado por el Laboratorio de Psicología y Tecnología (LabPsiTec).La depressió és una de les grans problemàtiques per a la salut mundial en l’actualitat. Cal llavors disposar d’intervencions eficaces per al seu tractament. Si bé en l’actualitat hi ha nombrosos tractaments psicològics amb suport empíric sobre la seva eficàcia, la població que es beneficia dels mateixos és molt reduïda, a causa dels alts costos de la seva implementació, alhora requerit ia la falta de professionals ben entrenats. L’ús d’Internet apareix com una eina útil per admi- nistrar els tractaments i superar els problemes que es presenten. En aquest sentit, el present treball té per objectiu presentar la descripció d›un programa d’intervenció autoaplicat a través d’Internet per al tractament de la depressió, desenvolupat pel Laboratori de Psicologia i Tecnologia (LabPsiTec).Este estudio fue financiado en parte por: 1) PROMOSAM (MINECO, Spain PSI2014-56303- REDT). 2) CIBER Fisiopatología Obesidad y Nutrición, CB06/03 Instituto Salud Carlos III, Spain

Accessibility in Health related Virtual Learning Environments

Supporting patients and informal carers is an essential task in managing chronic diseases. Many of these diseases are either directly linked to disabilities or are age related and, thus, also strongly correlated with potential disabilities. Furthermore, as the population ages it is becoming more and more common to give an old person with a set of mild disabilities acting as informal carer of another person with some type of chronic disease. Support material and professional help can be provided through the use of an eLearning platform. These platforms are usually known as Learning Management Systems (LMS) or Virtual Learning Environments (VLE). People with disabilities, linked to physical and/or cognitive impairments can obtain an extraordinary advantage from access to eLearning but, in practice, they find important barriers when the Virtual Learning Environments (VLE) and contents are not delivered in the suitable adapted forms according to their needs and preferences. All VLEs are supported by a set of different technological layers. Those layers can interfere with the final user gaining access to such adapted resources. Conflicts with user agents, assistive technologies and the delivery format of the resources are the most common problems. The accessibility of current VLEs, a mature technology, provides an interesting case study regarding the types of problems that can be encountered by users in current web application