Desafios da internet do futuro

Engenharia Eletrónica e TelecomunicaçõesAs capacidades de conetividade dos equipamentos móveis têm obrigado a constante mudança do modo de operação da rede, exigindo cada vez mais recursos. Visando as futuras redes 5G, existe a necessidade de evoluir as presentes redes móveis, melhorando as suas arquiteturas e mecanismos. Estas futuras redes, vistas como a próxima geração arquitetural das telecomunicações, tenta suportar a "explosão" do número de equipamentos ligados, serviços e tecnologias de acesso, apoiando-se fortemente nas redes definidas por software (do inglês, Software Defined Networks, SDN). Apesar de estas redes definidas por software, estarem a ser exploradas e implementadas no núcleo de rede, atualmente não contemplam o seu impacto em equipamentos sem-fios móveis, de forma a avaliar o possível suporte de controlo. Os desafios associados à extensão dos mechanismos e protocolos, como o OpenFlow, das redes definidas por software até aos equipamentos móveis, não só requerem o desenho de uma infra-estrutura capaz de suportar essa extensão, como também da sua avaliação e provenientes benefícios. Esta dissertação acompanha a tendência destas futuras redes, explorando a interação entre o equipamento móvel e a rede, em ambientes sem-fios heterogéneos, nos quais os mecanismos de SDN são extendidos até equipamentos móveis capazes de não só consumir, como também de produzir informação. Com isto, foi desenvolvida e implementada sobre uma rede sem-fios física uma arquitetura conceptual, na qual os mecanismos SDN são extendidos até ao terminal, suportando diferentes equipamentos móveis com múltiplos fluxos de dados. Os resultados obtidos, mostram a sua viabilidade em cenários de mobilidade sem congestionamento, visando benefícios em extender os mecanismos SDN para controlo de fluxos end-to-end em ambientes sem-fios.The connectivity capabilities of mobile wireless devices have been forever changing how networks operate, increasingly demanding resources from the network. This places a need for novel mobile network architectures and mechanisms, targeting tomorrows challenges, as envisaged by 5G networks research efforts. This future network, seen as the next generation telecommunications architecture, aims to tackle the explosion of connected devices, services and access technologies, relying its architecture on Software Defined Networks (SDN) to compose its underlying mechanisms. Notwithstanding, despite the need for novel control procedures to support and optimize increasingly challenging wireless mobile scenarios, SDN has been being deployed at the core and backhaul sections of the network and is not actively considering its impact directly over the wireless mobile terminals themselves. The challenges associated with the extension of SDN protocols, such as OpenFlow, all the way to the terminal requires the design and evaluation of frameworks that not only provide such mechanisms, but actually evaluate them and their benefits. This thesis shades a light on an important 5G trend, namely the interaction of the mobile node with the network, exploring a framework where SDN mechanisms are extended all the way to the mobile node, in heterogeneous wireless environments featuring different mobile nodes with multiple data flows, which act both as consumers and producers of information. In this way, flow-based mobility management becomes available to a network controller entity, via the OpenFlow protocol. The concept framework was implemented over a physical wireless testbed, validating its contribution in a mobile source-mobility use case, with results highlighting the promising benefits of extending SDN approaches for end-to-end flow control in wireless environments

Micro and macro network slicing: an experimental assessment of the impact of increasing numbers of slices

The fifth generation (5G) telecommunications network aims not only to enhance traffic performance and allow efficient management, but also to enable it to dynamically and flexibly adapt to the traffic demands of different vertical scenarios. In order to support that enablement, the underlying network procedures (i.e., network functions) are being virtualized and deployed in cloud-based environments, allowing for a more optimized usage of the infra-structure resources. In addition, such resources can be sliced, allowing isolated provisioning to specific network functions allocated to disparate vertical deployments. As network slices are envisaged by network operators to fulfill a small number of slices, able to cater towards essential 5G scenario demands (i.e., enhanced mobile broadband, massive machine-type communications and ultra reliable low-latency communications), the total amount of slices existing in a system is currently dictated by the underlying operational overhead placed over the cloud infra-structure. This paper explores the challenges associated to a vision where the network slicing concept is applied with a much greater level of granularity, ultimately allowing it to become a core mechanism of the network’s operation, with large numbers of co-existing slices. In that respect, this paper proposes an architecture framework for instantiation of network slices among network providers, which in turn are able to instantiate sub-slices tailored to use cases and vertical tenants. The evaluation of this concept is done following a two-pronged approach: firstly, different slice dimensions (i.e., from micro to macro) are proposed and discussed, pointing out the benefits and challenges of each proposed slice; secondly, we deployed a mobile network provider (MNO), using OpenAirInterface and FlexRAN frameworks, and experimentally evaluated the its slicing mechanisms. The objective is to provide insight on the challenges and impact associated with the deployment of an increasing amount of slices, using the same available infra-structural resources.publishe

An integration of slicing, NFV, and SDN for mobility management in corporate environments

Online access to information while on the move has conferred businesses with the capability to be constantly accessible and in operation, independently of geographical area or time zone. There are situations, however, that demand technical solutions for specific scenarios, such as controlled access to corporate-based content. Virtual Private Networks (VPNs) allow controlled remote access to con-tent, supporting scenarios such as teleworking. Nonetheless, such mechanisms are not commonly associated with the highly mobile users of today, which can traverse different types of access networks, while still keeping access to con-tent restricted to corporate network usage. In addition, as VPN mechanisms are disassociated from mobility procedures, service disruption can happen or specific mechanisms and clients can be required in end-user's equipment. This paper proposes a framework that leverages Network Slicing, enabled by Software Defined Networking and Network Function Virtualisation, to provide seamless and isolated access to corporate-based content while moving through heterogeneous networks. This solution allows Mobile Network Operators to dynamically instantiate isolated network slices for corporate users, and handover them between 3GPP and non-3GPP networks while users move away from the corporate network. In this way, they are able to keep access to corporate-based content in a transparent way, while maintaining access requirements for the servicebeing used. The framework was implemented and validated over an experimental testbed composed by mobile and Wi-Fi accesses, with results presenting improvements in terms of overhead signaling and data redirection without downtime nor stream reconnection.publishe

Selective laser melting of Ti6Al4V sub-millimetric cellular structures: prediction of dimensional deviations and mechanical performance

Ti6Al4V sub-millimetric cellular structures arise as promising solutions concerning the progress of conventional orthopedic implants due to its ability to address a combination of mechanical, physical and topological properties. Such ability can improve the interaction between implant materials and surrounding bone leading to longterm successful orthopedic implants. Selective Laser Melting (SLM) capability to produce high quality Ti6Al4V porous implants is in great demand towards orthopedic biomaterials. In this study, Ti6Al4V cellular structures were designed, modeled, SLM produced and characterized targeting orthopedic implants. For that purpose, a set of tools is proposed to overcome SLM limited accuracy to produce porous biomaterials with desired dimensions and mechanical properties. Morphological analyses were performed to evaluate the dimensional deviations noticed between the model CAD and the SLM produced structures. Tensile tests were carried out to estimate the elastic modulus of the Ti6Al4V cellular structures. The present work proposes a design methodology showing the linear correlations found for the dimensions, the porosity and the elastic modulus when comparing the model CAD designs with Ti6Al4V structures by SLM.This work was supported by FCT through the grant SFRH/BD/ 128657/2017 and the projects PTDC/EMS-TEC/5422/2014_ADAPT PROSTHESIS, NORTE-01-0145-FEDER-000018 – HAMaBICo and UID/ EEA/04436/2019

COMPARAÇÃO DA FORÇA MUSCULAR RESPIRATÓRIA DE ADOLESCENTES SAUDÁVEIS COM VALORES PREDITOS DE NORMALIDADE

The aim of this study was to verify the respiratory muscle strength (RMS) of healthy adolescents, and compare it with predicted normal values. The following were evaluated: (n=62, age=18.24±0.43 years, 48=female, 14=male) by means of the International Physical Activity Questionnaire (IPAQ) and FMR by manovacuometry by measuring Inspiratory Maximum Pressure (PiMáx) and Expiratory (PeMáx). Data were analyzed by Mann Whitney's t test, unpaired t-test and chi-square test. Regarding the IPAQ, 13 individuals were insufficiently active, 31 active and 18 very active. The values ​​of RMS were different from those predicted, being observed by the increase in the mean of the female PiMáx and the reduction in the male, in addition to the decrease of the PeMáx in both sexes. It was verified that the sample presented RMS impairment, which can impact on the health of this population, being a warning sign, besides recommending future analyzes of the predicted values ​​established.O objetivo deste estudo foi verificar a força muscular respiratória (FMR) de adolescentes saudáveis, e comparar com os valores de normalidades preditos. Foram avaliados (n=62; idade=18,24±0,43 anos; 48=sexo feminino; 14=masculino) por meio do Questionário Internacional de Atividade Física (IPAQ) e da FMR por manovacuometria pela mensuração da Pressão Máxima Inspiratória (PiMáx) e Expiratória (PeMáx). Os dados foram analisados pelos testes de Mann Whitney, t de student não pareado e qui-quadrado. Com relação ao IPAQ, 13 indivíduos apresentaram-se insuficientemente ativos, 31 ativos e 18 muito ativos. Os valores da FMR mostraram-se diferentes dos preditos, sendo observados pelo aumento em média da PiMáx no sexo feminino e redução no masculino, além da diminuição da PeMáx em ambos os sexos. Verificou-se que a amostra apresentou comprometimento da FMR, a qual pode impactar na saúde desta população, sendo um sinal de alerta, além de recomendar futuras análises dos valores preditos estabelecidos

Antimalarial Activity and Mechanisms of Action of Two Novel 4-Aminoquinolines against Chloroquine-Resistant Parasites

Chloroquine (CQ) is a cost effective antimalarial drug with a relatively good safety profile (or therapeutic index). However, CQ is no longer used alone to treat patients with Plasmodium falciparum due to the emergence and spread of CQ-resistant strains, also reported for P. vivax. Despite CQ resistance, novel drug candidates based on the structure of CQ continue to be considered, as in the present work. One CQ analog was synthesized as monoquinoline (MAQ) and compared with a previously synthesized bisquinoline (BAQ), both tested against P. falciparum in vitro and against P. berghei in mice, then evaluated in vitro for their cytotoxicity and ability to inhibit hemozoin formation. Their interactions with residues present in the NADH binding site of P falciparum lactate dehydrogenase were evaluated using docking analysis software. Both compounds were active in the nanomolar range evaluated through the HRPII and hypoxanthine tests. MAQ and BAQ derivatives were not toxic, and both compounds significantly inhibited hemozoin formation, in a dose-dependent manner. MAQ had a higher selectivity index than BAQ and both compounds were weak PfLDH inhibitors, a result previously reported also for CQ. Taken together, the two CQ analogues represent promising molecules which seem to act in a crucial point for the parasite, inhibiting hemozoin formation

Gestão virtualizada de mobilidade para redes futuras baseadas em particionamento de rede

The increasing number of mobile devices and their usage for Internet access has been at the origin of new networking challenges. In fact, mobile devices have evolved and are now able to both consume and produce live stream videos, while moving and taking advantage of multiple wireless access technologies. In parallel, network operators have been relying on Software Defined Networking (SDN) and Network Function Virtualization (NFV) mechanisms for enabling the network to dynamically and flexibly adapt to the different traffic requirements and use cases. Furthermore, 3GPP envisions the upcoming fifth generation (5G) of networks, as a holistic architecture able to aggregate different access technologies, and serve multiple vertical use cases (e.g., automotive and eHealth) with different traffic requirements (e.g., low latency and high peak data rates). Here, network slicing appears as the game changer, by allowing the network infrastructure to be divided into logically-isolated networks for supporting certain service types. Nevertheless, this rises new challenges related to the mobility management on such a highly dynamic and flexible holistic architecture. Aligned with this vision, this thesis proposes a virtualized mobility management mechanism for future slice-based networks, capable of providing the means to flexibly adapt the network (through slicing mechanisms) to the user’s communication requirements, while enabling seamless handovers between different access technologies. This mechanism was supported by the design of an SDN/NFV-based architecture, that was further evolved to accommodate slice and orchestration mechanisms for the dynamic instantiation and orchestration of network slices. The thesis provides proof-of-concept implementation and evaluation of the different network components, with results showing its feasibility and providing indicators for further enhancement and commercial deployment.O aumento do número de dispositivos móveis e a forma como são utilizados para o acesso à Internet tem estado na origem de diversos desafios de rede. Estes dispositivos têm vindo a evoluir e são agora capazes de consumir e produzir fluxos de vídeo em tempo real enquanto se movem e exploram múltiplos acessos a tecnologias sem-fios. Paralelamente, operadores de rede têm apostado em mecanismos de redes definidas por software (do inglês, SDN) e de funções de rede virtualizadas (do inglês, NFV), de forma a possibilitar a rede a adaptar-se de uma forma dinâmica e flexível a diversos tipos de requisitos de tráfego e casos de uso. Além disso, o 3GPP projecta a próxima rede de quinta geração (5G), como uma arquitetura holística capaz de agregar diferentes tecnologias de acesso, e servir múltiplos verticais (ex., indústria automóvel e saúde) com diferentes requisitos de tráfego (ex., baixa latência e elevados picos de transmissão de dados). Neste sentido, o particionamento de rede (do inglês, network slicing ou slicing) aparece como decisivo, permitindo a divisão da infra-estrutura de rede em redes logicamente isoladas, de forma a suportar determinados tipos de serviço. No entanto, isto levanta novos desafios relacionados com a gestão de mobilidade nesta arquitetura holística de redes altamente dinâmicas e flexíveis. Alinhada com esta visão, esta tese propõe um mecanismo de gestão virtualizada de mobilidade para redes futuras baseadas em particionamento de rede, capaz de adaptar a rede (através de mecanismos de slicing) aos requisitos de comunicação do utilizador, enquanto possibilita o handover transparente entre diferentes tecnologias de acesso. Este mecanismo foi suportado pelo desenho de uma arquitetura baseada em tecnologias SDN e NFV, sendo depois evoluída de forma a acomodar mecanismos de slicing e orquestração para instanciação e orquestração de network slices. A tese implementa e avalia provas de conceito dos diferentes componentes de rede, com os resultados a mostrar a sua viabilidade e providenciando indicadores para futuros melhoramentos e implementações comerciais.Programa Doutoral em Informátic

USE OF SUBSTRATES FOR GROWING Hancornia speciosa Gomes SEEDLINGS IN PLASTIC TUBES SUBSTRATOS NA PRODUÇÃO DE MUDAS DE MANGABEIRA EM TUBETES

Mangabeira (Hancornia speciosa Gomes) is a native fruit species from the Brazilian savannah. Its sexual propagation depends on a suitable substrate, because it interferes with seed germination and seedling establishment. The objective of this study was to evaluate the effect of different substrates for growing mangabeira seedlings in plastic tubes. The experiment was carried out in a greenhouse, in Cassilândia, Mato Grosso do Sul State, Brazil. The experimental design used was randomized blocks, with four replications and 15 seeds per plot. Five substrates were evaluated: A (washed sand + Plantmax® + soil, 1:1:3 v:v:v), B (carbonized rice husk + Plantmax® + soil, 1:1:3), C (carbonized rice husk + earthworm humus + soil, 1:1:3), D (bovine manure + Plantmax® + soil, 1:1:3), and E (bovine manure + soil, 2:3). The following parameters were evaluated: plant emergence percentage, emergence speed index, mortality percentage, seedling height, stem diameter, root length, number of leaves, chlorophyll leaf index, and shoot, root, and whole plant dry mass. From the results, substrates C, D, and E can be used for growing mangabeira seedlings in plastic tubes.<br /><p style="text-align: justify !important;"><span style="color: #000000;"><span style="font-family: Verdana, sans-serif;"><span style="font-size: x-small;"><span>A mangabeira (Hancornia speciosa Gomes) é uma espécie frutífera nativa do Cerrado brasileiro. A propagação sexuada desta espécie depende de um substrato adequado, pois o mesmo interfere no processo germinativo e no estabelecimento da muda. Objetivou-se estudar o efeito de diferentes substratos na produção de mudas de mangabeira em tubetes. O trabalho foi conduzido em casa-de-vegetação, em Cassilândia (MS). O delineamento experimental foi em blocos casualizados, com quatro repetições e 15 plantas por parcela. Foram utilizados os seguintes substratos: A (areia lavada + Plantmax® + solo, na proporção de 1:1:3 v:v:v), B (casca de arroz carbonizada + Plantmax® + solo, 1:1:3), C (casca de arroz carbonizada + húmus de minhoca + solo, 1:1:3), D (esterco bovino + Plantmax® + solo, 1:1:3) e E (esterco bovino + solo, 2:3). Avaliou-se a percentagem de emergência de plântulas, índice de velocidade de emergência, percentagem de mortalidade, altura da muda, diâmetro do colo, comprimento do sistema radicular, número de folhas, índice de clorofila foliar e massa seca da parte aérea, do sistema radicular e total. De acordo com os resultados obtidos, os substratos C, D e E podem ser utilizados para a produção de mudas de mangabeira em tubetes.</span></span></span></span></p><br /&gt