1,721,016 research outputs found
A Study on the Use of Convolutional Networks for RF Coverage Evaluations in Urban Environments
No full textU-nets are a type of Fully Convolutional Neural Network that has been widely adopted for image segmentation applications. In the present study, U-nets are applied to wide area prediction of radio propagation parameters in urban environment. Coverage maps are generated through simulations in a reference urban environment using a ray tracing tool. The generated dataset is then used to train and test the U-net. Preliminary results look promising
Optimization over time of reliable 5G-RAN with network function migrations
Full text linkResource optimization in 5G Radio Access Networks (5G-RAN) has to face the dynamics over time in networks with increasing numbers of nodes and virtual network functions. In this context, multiple objectives need to be jointly optimized, and key application requirements such as latency must be enforced. In addition, virtual network functions realizing baseband processing are subject to failures of the cloud infrastructure, requiring an additional level of reliability. Overall, this is a complex problem to solve, requiring fast algorithms to cope with dynamic networks while avoiding resource overprovisioning. This paper considers the problem of optimal virtual function placement in 5G-RAN with reliability against a single DU Hotel failure and proposes a solution that takes service dynamics into account. Firstly, the joint optimization of the total number of DU Hotels, of the RU-DU latency and of the backup DU sharing in a static traffic scenario is considered, and the DUOpt algorithm, based on Lexicographic Optimization, is proposed for solving efficiently this multiobjective problem. DUOpt splits the multi-objective problem into smaller Integer Linear Programming (ILP) subproblems that are sequentially solved, adopting for each one the most effective methodology to reduce the total execution time. The proposed DUOpt algorithm is extensively benchmarked to show its effectiveness in optimization of medium to large size networks: in particular, it is shown to greatly outperform an aggregate multi-objective approach, being able to compute optimal or close to optimal solutions for networks of several tens of nodes in computing times of a few seconds. Then, the problem is extended to a dynamic traffic scenario in which optimization is performed over time. In this context, in addition to the aforementioned objectives, the total number of network function migrations induced by multiple reoptimizations must be kept to the minimum. For solving efficiently this problem the DUMig algorithm is proposed, which extends and improves DUOpt. Reoptimization over a time horizon of one day in an illustrative dynamic traffic scenario is performed to evaluate the proposed DUMig algorithm against DUOpt, the latter being oblivious of the traffic dynamics. DUMig shows remarkable savings in the total number of migrations (above 86.1% for primary virtual functions and 83% for backup virtual functions) compared to DUOpt, while preserving near-optimal resource assignment
Oli di oliva vergini monovarietali: caratterizzazione della frazione fenolica e valutazione dell'attività antiossidante
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Effect of geographical origin and dimension of corms on saffron production in Basilicata Region (southern Italy)
No full textSaffron, the dried stigmas of the Crocus sativus L. flowers, is the most expensive spice in the world. It is mainly used as herbal medicine, flavoring agent and food coloring, due to the content of 3 main secondary metabolites: crocin, picrocrocin and safranal. The influence on saffron yield of 3 classes of corm horizontal diameter, 2.0-2.5 cm (D1), 2.6-3.5 cm (D2) and 3.6-4.5 cm (D3), and 3 geographical corm origins, ‘Sardinia’ (Italy), ‘Abruzzo’ (Italy) and ‘Kozani’ (Greece), was evaluated in this study. For this aim, an experimental field, based on a split-plot design with 3 reps, was conducted in ‘Genzano di Lucania’ (40°50’N, 16°08’E; 344 m a.s.l., Basilicata Region, southern Italy) during 2015-2016. At harvest time, yield, flower number m-2, stigma length and stigma fresh and dry weight, were detected. Besides, at the end of crop cycle number and dimension of daughter corms were determined. Results indicated that both yield, and stigma length were affected by geographical origin and dimension of corms. In particular, the highest stigma yield (6.0 kg ha-1) was obtained by D3 ‘Sardinia’ corms, followed by ‘Abruzzo’ and ‘Kozani’ (5.7 and 3.3 kg ha-1, respectively). The highest stigma length, 30.2 mm, was obtained by planting D3 ‘Sardinia’ corms, followed by ‘Abruzzo’ and ‘Kozani’. Moreover, D3 corms, at the end of crop cycle, generated more daughter corms able to flower (diameter ≥2.5 cm) than D1 ones. According to this study, there is a positive correlation between corm dimension and yield, stigma length and daughter corms production. In order to achieve higher productivity of saffron, the use of ‘Sardinia×D3’ is considered the best option in Basilicata Region environment
Saffron (Crocus sativus L.), the king of spices: An overview
No full textSaffron is obtained from the dried red stigmas of Crocus sativus L., an autumnal herbaceous flowering plant
belonging to the Iridaceae family. It is largely cultivated in Iran, India, Afghanistan, Greece, Morocco, Spain and
Italy. Saffron global production is estimated at 418 t y−1 on 121,338 ha. It is known as the most expensive spice
in the world and as beneficial for human health due to three main bioactive compounds: crocin, picrocrocin and
safranal. The demand for saffron is increasing worldwide for its interesting role in cuisine, medicine and cosmetics.
Due to the reduction of its production, recent investigations have been conducted to study how to
improve stigma yield, quality and antioxidant activity by selecting of corm geographical origin and climatic
conditions, using biostimulants such as mycorrhizal fungi as well as choosing irrigation regimes, drying methods
and storage processes. New research activities have been focused on the medicinal properties of this spice, such
as its neuroprotection in the context of ocular disease, free radical scavenging and detoxifying capacities. This
work offers an overview of the historical, economic, genetic, botanical, agronomic and qualitative traits of
saffron as well as the properties, traditional and recent uses of the spice as well as its by-products such as tepals,
stamens, styles, corms and leaves
Influence of calcium on the activity of enzymes involved in kiwifruit ripening
No full textFlesh firmness and total soluble solids content (SSC) are widely used to define post-harvest quality of kiwifruit during ripening. It is also interesting to investigate the other potential factors involved in this process. In this research, the role of calcium ions (Ca2+) on kiwifruit ripening (Actinidia deliciosa 'Hayward') was investigated. It is known that Ca2+ and other divalent ions delay ripening and senescence of kiwifruit. However, the way in which divalent ions act is not yet completely understood. The aim of this study has been to assess the effect of Ca2+ on some enzyme activities. Fruit quality parameters, such as fruit total calcium content, firmness, SSC and some enzyme activities were determined after harvest and during cold storage of fruits from plants grown in two different conditions of light exposition, namely exposed (E) and shaded (S). The results show that fruit firmness throughout the post-harvest period could be related with calcium content that was greater in exposed fruit than in shaded ones. During the whole storage period, amylase content was also higher in exposed fruits than in shaded ones while a slight difference between SSC respective trends was observed. A direct inhibitory effect of calcium on PG and on 23 KDa proteases was revealed. Even if pectinolytic proteins are considered the enzymes directly responsible for tissue softening, we also formulate an hypothesis in which kiwifruit proteases may be involved indirectly in ripening process
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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