Forecasting investment: A fishing contest using survey data

This paper assesses the usefulness of business surveys as a source of information for investment developments in Portugal. This will be achieved by what will be named a “fishing contest”, where the “participants” are bridge models, models based on principal components (derived from standard and non-standard methods), and models built with the outcome of partial least squares regressions. All models, based on quarterly data, are estimated using a general-to-specific approach and are designed to produce 1 to 4 out-of-sample direct forecasts. The accuracy of these forecasts is then compared with the one of autoregressive processes. The empirical evidence indicates that, in general, there is always a participant in the fishing context that produces a lower out-of-sample Root Mean Squared Error (RMSE) than the one associated with the autoregressive benchmark. In most cases, the combination of autoregressive processes with each participant reduces the RMSE further. A striking outcome is the relative accuracy of bridge models.

1 V CMOS subthreshold log domain PDM

A new CMOS circuit strategy for very low-voltage Pulse-Duration Modulators (PDM) is proposed. Optimization of voltage supply scaling below the sum of threshold voltages is based on Instantaneous Log Companding processing through the MOSFET operating in weak inversion. A 1 V VLSI PDM circuit for very low-voltage audio applications such as Hearing Aids is presented, showing good agreement between simulated and experimental data.Comisión Interministerial de Ciencia y Tecnología TIC97-1159, TIC99-1084European Union 2306

Estudi epidemiològic dels nivells d’activitat física en els estudiants d’educació secundària obligatòria

Les descripcions epidemiològiques ens indiquen la situació en què es troba una població respecte als aspectes de salut, i en aquest cas concret, la seva relació amb l’activitat física. El coneixement d’aquestes investigacions podrà ser utilitzat per fomentar la prevenció i el control d’algunes malalties, i també per a la promoció de la salut. En aquesta investigació pretenem de realitzar una descripció epidemiològica de l’Activitat Física entre una mostra de l’alumnat d’Educació Secundària Obligatòria de l’IES San Alberto Magno de Sabiñánigo, a Osca. Vam utilitzar el qüestionari “Four by one-day Physical Activity Questionnaire” i hi vam recollir l’estimació d’activitat física total, dintre i fora de l’àmbit escolar, mitjançant quatre registres. Vam concloure que es van detectar alts nivells d’inactivitat, més acusats en la població femenina i que augmenta amb l’edat. És molt interessant expressar la despesa energètica dividint-la en activitats laborals, esportives i quotidianes. D’altra banda, no es van reflectir relacions significatives entre la despesa energètica i altres variables, com ara tabac, televisió o estudi, però aporten informació sobre els hàbits dels adolescents. Per les dades obtingudes es dedueix que és factible l’ús de la percepció de l’alumne sobre el seu nivell de realització d’activitat física

Estudio epidemiológico de los niveles de actividad física en los estudiantes de Educación Secundaria Obligatoria

Las descripciones epidemiológicas nos indican la situación en la que se encuentra una población respecto a los aspectos de salud, y en este caso concreto su relación con la actividad física.  El conocimiento de estas investigaciones podrá ser utilizado para fomentar la prevención y el control de algunas  enfermedades, así como para la promoción de la salud. En esta investigación pretendemos realizar una descripción epidemiológica de la Actividad Física entre una muestra del alumnado de Educación Secundaria Obligatoria del I.E.S. San Alberto Magno de Sabiñánigo, en Huesca. Utilizamos el cuestionario  “Four by one-day Physical Activity Questionaire” recogiendo la  estimación de  actividad física total, dentro y fuera ámbito escolar, mediante  cuatro registros Concluimos que se detectaron altos niveles de inactividad, más acusados en la población femenina y que aumenta con la edad. Es muy  interesante expresar el gasto energético dividiéndolo en actividades laborales, deportivas y cotidianas. Por otra parte no se reflejaron relaciones significativas entre el gasto energético y otras variables como tabaco, televisión o estudio, pero aportan información sobre los hábitos de los adolescentes.  Por los datos obtenidos se deduce que es factible el uso de la percepción del alumno sobre su nivel de realización de actividad física

Key-Value Storage for handling data in mobile devices

In the current era of technology, computers have shrinked to the point that more than half of the world population always carries one with them - their mobile devices. These are used in all sorts of different activities, constantly generating information that needs to be stored or processed somewhere. To cope with the huge amounts of data generated by all of these devices, applications have resorted to Cloud services to provide them with the much needed computational and storage resources, but as these remote infrastructures still represented a bottleneck communication wise, a new paradigm has been emerging, Edge Computing. Instead of processing and storing all the data in more distant cloud services, the data is spread among mobile devices and edge servers connected in a shared network. In order to fully take advantage of the low latency times experienced in the Edge, applications still needed a distributed storage edge-oriented system, capable of handling the contents generated by all of these mobile devices. The current state-of-the-art storage systems are able to provide these applications with a storing platform that uses mobile devices or edge servers as data storing points, but neither uses both. In this thesis we propose a Key-Value Edge Storage System named Basil, that uses both mobile devices and edge infrastructures as nodes of the system, capable of providing users from different locations with a cohesive and consistent distributed storage system. Furthermore, we will test our KV store against existing NoSQL storage models deployed in the edge, as well as its own performance while varying the number of nodes it relies on

A novel admission control scheme for network slicing based on squatting and kicking strategies

New services and applications impose differentquality of service (QoS) requirements on network slicing. Tomeet differentiated service requirements, current Internet servicemodel has to support emerging real-time applications from 5Gnetworks. The admission control mechanisms are expected tobe one of the key components of the future integrated serviceInternet model, for providing multi-level service guarantees withthe different classes (slices) of services. Therefore, this paperintroduces a new flexible admission control mechanism, basedon squatting and kicking techniques (SKM), which can beemployed under network slicing scenario. From the results, SKMprovides 100% total resource utilization in bandwidth contextand 100% acceptance ratio for highest priority class underdifferent input traffic volumes, which cannot be achieved byother existing schemes such as AllocTC-Sharing model due topriority constraints.Peer ReviewedPostprint (published version