Video quality evaluation in IP videoconference between fixed and mobile devices

The integration of the mobile network with the fixed network, by using IP, has allowed the appearance of packet-based videoconference between fixed and mobile devices. Current mobile IP networks are sized for http traffic and its behavior is best-effort. In this context, it becomes compulsory to evaluate and measure the video quality when packets are transmitted through these networks. By doing this, results obtained could be used to size future networks and/or define different Quality of Service politics in future IMS networks. The objective of this final career project is to evaluate possible video quality degradation in videoconference applications through IP integrated network (fixed + mobile). A study of the currently available video quality evaluation tools will be made and, as well, a specific system for the video quality evaluation in communications between the IP fixed network and the 3.5G IP mobile network, using own methodology, will be developed. Several evaluation scenarios will be defined, with different mobile – fixed network configurations in order to identify the elements susceptible of degradate the quality of the video. The developed system must be able to process the video sequences in origin and in reception, so it will be a referential system

L'increment de CO2 no ha fet augmentar el creixement dels arbres

Durant el segle passat la concentració atmosfèrica de CO2 va augmentar en 50 parts per milió, provocant un increment en l'eficiència en l'ús de l'aigua per part de les diverses espècies d'arbres que viuen en els boscos d'arreu del món. Tanmateix, aquesta major eficiència en l'ús de l'aigua no ha comportat, en general, un major creixement dels arbres arreu del món i, per tant, tampoc un augment de la seva capacitat d'embornal de CO2 com el que s'asumeix en els models de canvi climàtic. Altres factors com el canvi climàtic (especialment la sequera), la limitació de nutrients o l'aclimatació a llarg termini a una elevada concentració de CO2 han impedit que els arbres puguin treure profit dels efectes potencials d'aquest augment de CO2 per poder incrementar el seu creixement.Durante el siglo pasado la concentración atmosférica de CO aumentóen 50 partes por millón, provocando un incremento en la eficiencia en eluso del agua de las diversas especies de árboles que viven en losbosques de todo el mundo. No obstante, esta mayor eficiencia en el usodel agua no ha comportado, en general, un mayor crecimiento de los árboles de todo el mundo y por lo tanto tampoco un aumento de su capacidad como sumidero de CO como el que se asume en los modelos de cambio climático. Otros factores como el cambio climático (especialmente la sequía), la limitación de nutrientes o la aclimatación a largo plazo a una elevada concentración de CO han impedido que los árboles, puedan aprovechar los efectos potenciales de este aumento de CO para poder incrementar su crecimient

Statistical analysis of the likelihood of bars in disk galaxies

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2019, Tutor: José Maria Solanes MajúaWe make use of HI content information from the Arecibo Legacy Fast ALFA survey catalog to study the stellar and atomic gas content of barred disk galaxies. These 21-cm observations are augmented with the extensive optical data gathered in the NASA-Sloan Atlas catalog and with information on galaxy morphologies and bar probabilites included in the catalog by Domínguez Sánchez et al. (2018). We find, in agreement with previous studies, that the bar probability ofthe disk population shows a bimodal distribution, both in terms of the stellar mass and the (g -- r) optical color, which we attribute to the tendency of the late disks to be low-mass, blue objects, while earlier spirals are more massive and redder. We also confirm that the bar fraction decreases with increasing gas mass fraction and neutral hydrogen excess. This anticorrelation results from the inhibiting effect the gas has in the formation of bar

Food sovereignty and emerging diseases

PòsterJun

Climate drives global soil carbon sequestration and crop yield changes under conservation agriculture

This research was supported by the Natural Science Foundation of China (grant Nos. 41530533 and 41573069) and the National Key R&D Program of China (grant No. 2017YFE0104600). We thank Prof. Xuhui Lee in Yale University, Dr. Zhongkui Luo in Zhejiang University, Prof. Ben Smith in Lund University and Dr. Xunyu Hu in East China Inventory and Planning Institute, State Forestry and Grassland Administration for their helpful comments that led to the improvement of this paper.Peer reviewedPostprin

Moving toward Net-Zero Emissions Requires New Alliances for Carbon Dioxide Removal

The 1.5 degrees C target will require removing at least some of the carbon dioxide (CO2) previously emitted. Knowledge on how this can be done has been increasing, though barriers remain concerning governance, policy, and acceptability. For the 26th session of the Conference of the Parties (COP26) to move beyond an academic debate on CO2 removal (CDR), a broader alliance of research and policy communities, industry, and the public is needed

Multi-decadal increase of forest burned area in Australia is linked to climate change

Fire activity in Australia is strongly affected by high inter-annual climate variability and extremes. Through changes in the climate, anthropogenic climate change has the potential to alter fire dynamics. Here we compile satellite (19 and 32 years) and ground-based (90 years) burned area datasets, climate and weather observations, and simulated fuel loads for Australian forests. Burned area in Australia’s forests shows a linear positive annual trend but an exponential increase during autumn and winter. The mean number of years since the last fire has decreased consecutively in each of the past four decades, while the frequency of forest megafire years (>1 Mha burned) has markedly increased since 2000. The increase in forest burned area is consistent with increasingly more dangerous fire weather conditions, increased risk factors associated with pyroconvection, including fire-generated thunderstorms, and increased ignitions from dry lightning, all associated to varying degrees with anthropogenic climate change