Multimedia Resource Allocation in mmWave 5G Networks

The 5G network infrastructure is driven by the evolution of today's most demanding applications. Already, multimedia applications such as on-demand HD video and IPTV require gigabit- per-second throughput and low delay, while future technologies include ultra HDTV and machine-to-machine communication. Mm-Wave technologies such as IEEE 802.15.3c and IEEE 802.11ad are ideal candidates to deliver high throughput to multiple users demanding differentiated QoS. Optimization is often used as a methodology to meet throughput and delay constraints. However, traditional optimization techniques are not suited to a mixed set of multimedia applications. Particle swarm optimization (PSO) is shown as a promising technique in this context. Channel-time allocation PSO (CTA-PSO) is successfully shown here to allocate resource even in scenarios where blockage of the 60 GHz signal poses significant challenges.

Ultrafast charge dynamics in an amino acid induced by attosecond pulses

In the past few years, attosecond techniques have been implemented for the investigation of ultrafast dynamics in molecules. The generation of isolated attosecond pulses characterized by a relatively high photon flux has opened up new possibilities in the study of molecular dynamics. In this paper, we report on experimental and theoretical results of ultrafast charge dynamics in a biochemically relevant molecule, namely, the amino acid phenylalanine. The data represent the first experimental demonstration of the generation and observation of a charge migration process in a complexmolecule, where electron dynamics precede nuclear motion. The application of attosecond technology to the investigation of electron dynamics in biologically relevant molecules represents a multidisciplinary work, which can open new research frontiers: those in which few-femtosecond and even subfemtosecond electron processes determine the fate of biomolecules. It can also open new perspectives for the development of new technologies, for example, in molecular electronics, where electron processes on an ultrafast temporal scale are essential to trigger and control the electron current on the scale of the molecule.

Dual-Diversity Combining for Constrained Resource Allocation and Throughput Maximization in OFDMA Networks

Al Rawi, Anas F., Emiliano Garcia-Palacios, Sonia Aissa, Charalampos C. Tsimenidis, and Bayan S. Sharif. "Dual-Diversity Combining for Constrained Resource Allocation and Throughput Maximization in OFDMA Networks." In Vehicular Technology Conference (VTC Spring), 2013 IEEE 77th, pp. 1-5. IEEE, 2013.

Cross-layer Framework for Fine-grained Channel Access in Next Generation High-density WiFi Networks

Densely deployed WiFi networks will play a crucial role in providing the capacity for next generation mobile internet. However, due to increasing interference, overlapped channels in WiFi networks and throughput efficiency degradation, densely deployed WiFi networks is not a guarantee to obtain higher throughput. An emergent challenge is how to efficiently utilize scarce spectrum resources, by matching physical layer resources to traffic demand. In this aspect, access control allocation strategies play a pivotal role but remain too coarse-grained. As a solution, this research proposes a flexible framework for fine-grained channel width adaptation and multi-channel access in WiFi networks. This approach, named SFCA (Sub-carrier Fine-grained Channel Access), adopts DOFDM (Discontinuous Orthogonal Frequency Division Multiplexing) at the PHY layer. It allocates the frequency resource with a sub-carrier granularity, which facilitates the channel width adaptation for multi-channel access and thus brings more flexibility and higher frequency efficiency. The MAC layer uses a frequency-time domain backoff scheme, which combines the popular time-domain BEB scheme with a frequency-domain backoff to decrease access collision, resulting in higher access probability for the contending nodes. SFCA is compared with FICA (an established access scheme) showing significant outperformance. Finally we present results for next generation 802.11ac WiFi networks.

Internet of Things. A proposed secured network topology

The myriad of technologies and protocols working at different layers pose significant security challenges in the upcoming Internet of Things (IoT) paradigm. Security features and needs vary from application to application and it is layer specific. In addition, security has to consider the constraints imposed by energy limited sensor nodes and consider the specific target application in order to provide security at different layers. This paper analyses current standardization efforts and protocols. It proposes a generic secured network topology for IoT and describes the relevant security challenges. Some exploitation examples are also provided.

Control of ionization and dissociation of H2+ by elliptically polarized ultra-short VUV laser pulses

Resonance-enhanced multiphoton ionization of H₂ ⁺ exposed to elliptically polarized VUV laser pulses is investigated. Differential cross sections for nuclei and electron are obtained using numerical solutions of the time-dependent Schrödinger equation. In this work in progress, we explore the dependence of the dissociative ionization observables with the polarization of the light.

Plan estratégico para el área administrativa del Centro de Negocios Unicornio II

Al momento existe una crisis administrativa y económica en el Centro de Negocios generada por la pérdida de imagen de la institución frente al público, lo que se refleja en bajos ingresos económicos y falta de recursos para la inversión en mejoramientos y pago de servicios básicos. El objetivo del presente trabajo es direccionar a la institución, en la toma de decisiones en el año 2005, para lograr su éxito y permanencia en el mercado en que se desenvuelve, logrando mejorar el trabajo del área administrativa y la competitividad frente a los demás Centros Comerciales. Para lo cual se plantea proyectos y mejoras del servicio que se fomenten desde la Administración . El edificio Unicornio II se crea en el año 1992 bajo el régimen de propiedad horizontal, antes de concluida la edificación, la empresa constructora se declara en banca rota, creando un problema para sus tres área que son: departamentos, oficinas y locales comerciales. La administración del Centro de Negocios está descentralizada de las demás áreas del edificio. En el año 2004 la cartera por cobrar es de 75,757.59 dólares y apenas una cancelación de 31,768.81 dólares; causando que para el mes de abril del 2005 las deudas por alícuotas puedan llegar a los 176, 907 dólares. Debido a la notoria falta de recursos, la Administración difícilmente puede cubrir los gastos mensuales por concepto de servicios básicos comunales, por lo que existe una imagen de descuido que crea inconformidad entre los pocos copropietarios que cumplen y una perdida de competitividad que pone en peligro la existencia de las unidades de negocio. La falta de recursos impide que la administración pueda realizar adecuaciones y mantenimientos que mejoren la apariencia y servicio que reciben los clientes, causando una falta de competitividad respecto de los centros comerciales competidores y de mantenerse las cosas como están el Centro de Negocios corre el riesgo de desaparecer y generar pérdidas económicas para quienes han realizado sus actividades comerciales en el Unicornio por varios años.

Diminuição do pico de cheia na rede de drenagem de águas pluviais através do sistema de aproveitamento de água da chuva

Dissertação de mest., Engenharia de Recursos Hídricos, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2010

Aguardentes de medronho

A aguardente de medronho, muitas vezes designada apenas por medronho, é um destilado que continua a ser produzida, essencialmente de forma artesanal. A sua produção, tudo indica, ter iniciado em Monchique, no século X, pelos Árabes. A qualidade deste destilado passou por fases polémicas, principalmente pela escassez de mão-de-obra. Depois de um período de investigação laboratorial e de trabalho com produtores locais, envolvendo várias Instituições da região, a qualidade da aguardente de medronho foi paulatinamente melhorando. O controlo de qualidade das aguardentes é feito, essencialmente, recorrendo a técnicas cromatografias e espetrofotométricas. Técnicas que permitem diferenciar não só a qualidade, como criar o perfil de cada tipo de aguardente. O Algarve produz também aguardente de figo, alfarroba, mel, vínica, bagaceira e desde 2009 aguardente de batata-doce de Aljezur. Podem ainda encontrar-se pequenas produções de aguardente de alperce ou de ameixa. Presentemente a grande maioria das aguardentes de medronho produzidas no Algarve apresentam os seus parâmetros de qualidade em conformidade com a legislação em vigor (regulamento (CE) nº nº110/2008 de 15 de Janeiro e Decreto-Lei nº 238/2000 de 26 de Setembro). Existindo já um vasto conjunto destas bebidas que mereciam uma diferenciação superior ao estabelecido pela atual legislação, que é ainda bastante permissiva nomeadamente em relação à acidez total, cujo máximo permitido é de 200 g/hl de álcool puro (a.p), (expresso em ácido acético), quando deveria ser de 30 ou em relação ao teor em acetato de etilo, que permite teores de 300 g/hl (a.p), quando não deveria ultrapassar 150. A aposta no envelhecimento ainda é fraca, mas com grande potencial de desenvolvimento. Em Monchique alguns produtores continuam a manter um estágio de 3 meses em pipas, essencialmente, de madeira de castanho. Noutras localidades, muito timidamente, surge um ou outro produtor a experimentar o uso de pipas de carvalho. A grande aposto dos últimos anos na região tem sido na produção de aguardentes preparadas com mel e principalmente nos licores.

Geometria e silêncio das mulheres nos tapetes berberes do médio atlas

A investigação desenvolvida neste estudo pretende conduzir a uma reflexão sobre a relação que se estabelece entre a geometria e o pensamento abstracto de mulheres berberes, maioritariamente analfabetas e que, até há bem pouco tempo (talvez ainda em algumas regiões rurais, mais isoladas, de Marrocos), viviam segregadas. Falamos, sim, desses berberes que chegaram e se instalaram nas montanhas de Marrocos, muito antes da chegada dos árabes e que, ainda hoje continuam a fazer história, deixando que o seu quotidiano, o seu modo de vida seja ditado pelo enquadramento numa paisagem magnífica, que dá azo a um tempo mais lento, mais contemplativo, mais devoto. Reflectir-se-á sobre a originalidade dos tapetes berberes, cujo produto final não está delineado, à partida, mas que tem a ver com uma concepção interior da obra, que promove a liberdade de criação destas mulheres. Procurar-se-á compreender o tapete como uma forma de arte doméstica, conceptual, que emerge de um pensamento que, sendo geométrico (universal), se torna abstracto ou só compreensível por um grupo restrito de iniciados.1 O tapete tornou-se o segredo destas mulheres. E só o é, porque nós (todos, à excepção das mulheres berberes) não o conseguimos entender. Falamos de um “código” que só é perceptível quando é conhecida a matriz do pensamento. Pode até conhecer-se a técnica e a estética dos tapetes, identificar-se as diferentes tipologias e os materiais utilizados, mas tornar-se-á impossível criá-los, como estas mulheres o fazem, sem planos pré-estabelecidos. É essa maneira de produzir, quase inata para estas mulheres, que está fora do nosso alcance lógico.

Identification of Potential Sources of Airborne Olea Pollen in the Southwest Iberian Peninsula

This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009–2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (south-western Spain) and Évora (south-eastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources during conditions with slow air mass movements. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies that examine sources and the atmospheric transport of pollen are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop.

Comparison of Poaceae Pollen Counts Recorded at Sites in Portugal, Spain and the UK

The main aim of this study was to analyse the temporal and spatial variations in grass (Poaceae) pollen counts (2005–2011) recorded in Évora (Portugal), Badajoz (Spain) and Worcester (UK). Weekly average data were examined using nonparametric statistics to compare differences between places. On average, Évora recorded the earliest start dates of the Poaceae pollen seasons and Worcester the latest. The intensity of the Poaceae pollen season varied between sites, with Worcester usually recording the least and Évora the most grass pollen in a season. Mean durations of grass pollen seasons were 77 days in Évora, 78 days in Badajoz and 59 days in Worcester. Overall, longer Poaceae pollen seasons coincided with earlier pollen season start dates. Weekly pollen data, from March to September, from the three pollen-monitoring stations studied were compared. The best fit and most statistically significant correlations were obtained by moving Worcester data backward by 4 weeks (Évora, r = 0.810, p < 0.001) and 5 weeks (Badajoz,r = 0.849, p < 0.001). Weekly data from Worcester therefore followed a similar pattern to that of Badajoz and Évora but at a distance of more than 1,500 km and 4–5 weeks later. The sum of pollen recorded in a season was compared with monthly rainfall between January and May. The strongest positive relationship between season intensity and rainfall was between the annual sum of Poaceae pollen recorded in the season at Badajoz and Évora and total rainfall during January and February. Winter rainfall noticeably affects the intensity of Poaceae pollen seasons in Mediterranean areas, but this was not as important in Worcester.

Potential Sources of Airborne Alternaria spp. spores in South-west Spain

Fungi belonging to the genus of Alternaria are recognised as being significant plant pathogens, and Alternaria allergens are one of themost important causes of respiratory allergic diseases in Europe. This study aims to provide a detailed and original analysis of Alternaria transport dynamics in Badajoz, SW Spain. This was achieved by examining daily mean and hourly observations of airborne Alternaria spores recorded during days with high airborne concentrations of Alternaria spores (N100 s m−3) from 2009 to 2011, as well as four inventory maps of major Alternaria habitats, the overall synoptic weather situation and analysis of air mass transport using Hybrid Single Particle Lagrangian Integrated Trajectory model and geographic information systems. Land use calculated within a radius of 100 km from Badajoz shows that crops and grasslands are potentially the most important local sources of airborne Alternaria spores recorded at the site. The results of back trajectory analysis showthat, during the examined four episodes, the two main directions where Alternaria source areas were located were: (1) SW–W; and (2) NW–NE. Regional scale and long distance transport could therefore supplement the airborne catch recorded at Badajoz with Alternaria conidia originating from sources such as crops and orchards situated in other parts of the Iberian Peninsula.

Relações sinuosas: Portugal e o mundo árabe, 1950-1973

Nas três últimas décadas do colonialismo português, as políticas destinadas às populações muçulmanas da Guiné e de Moçambique passaram da hostilidade mais ou menos aberta para uma estratégia de sedução, com vista a promover um “Islão português” e a usar certos sectores muçulmanos no combate aos movimentos nacionalistas. Esta transição teve também uma componente transnacional, na medida em que se quis alargar a intervenção portuguesa a um espaço estratégico designado como “mundo islâmico”. O presente artigo procura analisar essa intervenção, debruçando-se sobre o pensamento geopolítico que a informou e as suas aplicações diplomáticas, em particular no relacionamento com os países árabes.