21 research outputs found

    A novel approach for security function graph configuration and deployment

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    Network virtualization increased the versatility in enforcing security protection, by easing the development of new security function implementations. However, the drawback of this opportunity is that a security provider, in charge of configuring and deploying a security function graph, has to choose the best virtual security functions among a pool so large that makes manual decisions unfeasible. In light of this problem, the paper proposes a novel approach for synthesizing virtual security services by introducing the functionality abstraction. This new level of abstraction allows to work in the virtual level without considering the different function implementations, with the objective to postpone the function selection jointly with the deployment, after the configuration of the virtual graph. This novelty enables to optimize the function selection when the pool of available functions is very large. A framework supporting this approach has been implemented and it showed adequate scalability for the requirements of modern virtual networks

    Automated optimal firewall orchestration and configuration in virtualized networks

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    Emerging technologies such as Software-Defined Networking and Network Functions Virtualization are making the definition and configuration of network services more dynamic, thus making automatic approaches that can replace manual and error-prone tasks more feasible. In view of these considerations, this paper proposes a novel methodology to automatically compute the optimal allocation scheme and configuration of virtual firewalls within a user-defined network service graph subject to a corresponding set of security requirements. The presented framework adopts a formal approach based on the solution of a weighted partial MaxSMT problem, which also provides good confidence about the solution correctness. A prototype implementation of the proposed approach based on the z3 solver has been used for validation, showing the feasibility of the approach for problem instances requiring tens of virtual firewalls and similar numbers of security requirements

    Il progetto pro-dsa di bologna: assessment dinamico e interventi precoci nel primo biennio della scuola primaria.

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    Il primo biennio della scuola primaria costituisce un periodo di primaria importanza per l’individuazione precoce delle difficoltà di apprendimento. L’individuazione precoce tuttavia deve essere accompagnata da interventi di potenziamento didattico e da valutazioni dinamiche che permettano di comprendere le traiettorie di sviluppo, come indicato dall’approccio RTI (Response to Intervention) (Fuchs & Fuchs, 2006). Nel presente contributo verranno presentati i dati relativi al progetto PRO-DSA di Bologna. Il progetto prevede la somministrazione, da parte delle insegnanti, di prove collettive di letto scrittura (Prove ZERO) a Gennaio e Maggio della classe prima e ad Aprile della classe seconda. Sono previste attività di potenziamento didattico, approfondimenti diagnostici e interventi specifici lungo il percorso. Verranno discussi i dati relativi alla rilevazione di indicatori di difficoltà di apprendimento nella letto-scrittura nelle diverse fasi del progetto

    Fermentação alcoólica de substrato amiláceo e hidrolisado enriquecido com melaço de cana Alcoholic fermentation of starchy hidrolisated substrate with sugar cane residue

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    A farinha constitui um dos principais produtos da mandioca, e seu uso é muito difundido em todo o País. Durante o processamento da mandioca para a obtenção da farinha é gerado um resíduo sólido proveniente da decantação da manipueira, o qual é composto essencialmente por amido. Diante da importância do aproveitamento de resíduos agroindústrias para a geração de energia e como fonte de renda para as empresas, com este trabalho objetivou-se avaliar o efeito da adição de melaço (resíduo da produção de açúcar de cana) no preparo de soluções de amido para hidrólise enzimática e fermentação alcoólica. Os resultados obtidos demonstraram que a adição de melaço no resíduo amiláceo inicial em doses a partir de 10% levou a um aumento no teor de açúcares no mosto promovendo um aumento de 112% na produção de etanol, em relação ao substrato sem aditivo. Contudo, a seleção de leveduras adaptadas ao substrato faz-se necessária para um melhor rendimento em etanol.<br>The cassava flour is a one of most important commercial product of cassava industries. During the cassava flour processing is obtained a solid residue from 'manipueira' decantation, which is characterized by high level of starch. Due the importance of the residue usage as energy source and income product for industries this work had as purpose to evaluate the addition of sugarcane residue (melaço) as supplementary raw material in hydrolysis and fermentation process of cassava starch solution for ethanol production. The results showed that the increase of sugarcane residue percentage in initial solution (> 10%) caused the increase of sugar concentration in must and high ethanol yield (increase of 112% when compared with substrate the without sugarcane residue). The yeast selection and substrate adaptation is necessary for increase of ethanol production from cassava starch residue

    Tackling climate risk to sustainably intensify smallholder maize farming systems in southern Africa

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    Sustainable intensification (SI) of low input farming systems is promoted as a strategy to improve smallholder farmer food security in southern Africa. Using the Limpopo province South Africa as a case study (four villages across a climate gradient), we combined survey data (140 households) and quantitative agronomic observations to understand climate-induced limitations for SI of maize-based smallholder systems. Insights were used to benchmark the agroecosystem model Agricultural Production System sIMulator, which was setup to ex ante evaluate technology packages (TPs) over 21-seasons (1998–2019): TP0 status quo (no input, broadcast sowing), TP1 fertiliser (micro dosing), TP2 planting density (recommended), TP3 weeding (all removed), TP4 irrigation, TP5 planting date (early, recommended), and TP6 all combined (TPs 1–5). An additional TP7 (forecasting) investigated varying planting density and fertiliser in line with weather forecasts. Input intensity levels were low and villages expressed similar challenges to climate risk adaptation, with strategies mostly limited to adjusted planting dates and densities, with less than 2% of farmers having access to water for irrigation. Simulations showed that combining all management interventions would be expected to lead to the highest mean maize grain yields (3200 kg ha ^−1 across villages) and the lowest harvest failure risk compared to individual interventions. Likewise, simulations suggested that irrigation alone would not result in yield gains and simple agronomic adjustments in line with weather forecasts indicated that farmers could expect to turn rainfall variability into an opportunity well worth taking advantage of. Our study emphasises the need for a cropping systems approach that addresses multiple crop stresses simultaneously
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