1,995 research outputs found

    Primitive abundant and weird numbers with many prime factors

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    We give an algorithm to enumerate all primitive abundant numbers (briefly, PANs) with a fixed Ω\Omega (the number of prime factors counted with their multiplicity), and explicitly find all PANs up to Ω=6\Omega=6, count all PANs and square-free PANs up to Ω=7\Omega=7 and count all odd PANs and odd square-free PANs up to Ω=8\Omega=8. We find primitive weird numbers (briefly, PWNs) with up to 16 prime factors, improving the previous results of [Amato-Hasler-Melfi-Parton] where PWNs with up to 6 prime factors have been given. The largest PWN we find has 14712 digits: as far as we know, this is the largest example existing, the previous one being 5328 digits long [Melfi]. We find hundreds of PWNs with exactly one square odd prime factor: as far as we know, only five were known before. We find all PWNs with at least one odd prime factor with multiplicity greater than one and Ω=7\Omega = 7 and prove that there are none with Ω<7\Omega < 7. Regarding PWNs with a cubic (or higher) odd prime factor, we prove that there are none with Ω≤7\Omega\le 7, and we did not find any with larger Ω\Omega. Finally, we find several PWNs with 2 square odd prime factors, and one with 3 square odd prime factors. These are the first such examples.Comment: New section on open problems. A mistake in table 2 corrected (# odd PAN with Omega=8). New PWN in table 5, last line, 2 squared prime factors, Omega=15. Updated bibliograph

    Using Apache Lucene to Search Vector of Locally Aggregated Descriptors

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    Surrogate Text Representation (STR) is a profitable solution to efficient similarity search on metric space using conventional text search engines, such as Apache Lucene. This technique is based on comparing the permutations of some reference objects in place of the original metric distance. However, the Achilles heel of STR approach is the need to reorder the result set of the search according to the metric distance. This forces to use a support database to store the original objects, which requires efficient random I/O on a fast secondary memory (such as flash-based storages). In this paper, we propose to extend the Surrogate Text Representation to specifically address a class of visual metric objects known as Vector of Locally Aggregated Descriptors (VLAD). This approach is based on representing the individual sub-vectors forming the VLAD vector with the STR, providing a finer representation of the vector and enabling us to get rid of the reordering phase. The experiments on a publicly available dataset show that the extended STR outperforms the baseline STR achieving satisfactory performance near to the one obtained with the original VLAD vectors.Comment: In Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2016) - Volume 4: VISAPP, p. 383-39

    Effects of protein supplementation in fitness world: A 12-week cross-over studio

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    The aim of this project was to evaluate the effect of isolated protein supplementation in young amateur athletes. Sixteen subjects aged between 20 and 30 were recruited for this study. Before to start sports performance was assessed at T0, in all subjects, using physical performance test and evaluated body composition. Therefore, the subjects were randomly assigned in two groups (group A and B) of 8 subjects each. The group A start to intake 30 g of protein powder diluted in water after each training session (3 times a week) for six weeks (T0) whilst the group B was the placebo. After 6 weeks (T1), the measurement were repeated for all subjects and the group A became placebo and the group B started with the supplementation. At the end of 6 weeks (T2) we carried out all the tests were performed again. Results showed a significant improvement in almost all tests between T0 and T2 within the same group (p < .05), but not significant difference was found between the start and the end of protein’s intake period in both groups. In conclusion, supplementation did not have affect the performance and body composition significantly. Instead, training seems to influence the performance more the supplementation

    The wild taxa utilized as vegetables in Sicily (Italy): A traditional component of the Mediterranean diet

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    Background: Wild vegetables in the Mediterranean Basin are still often consumed as a part of the diet and, in particular, there is a great tradition regarding their use in Sicily. In this study, an ethnobotanical field investigation was carried out to (a) identify the wild native taxa traditionally gathered and consumed as vegetables in Sicily, comparing the collected ethnobotanical data with those of other countries that have nominated the Mediterranean diet for inclusion in the UNESCO Representative List of the Intangible Cultural Heritage of Humanity and (b) highlight new culinary uses of these plants. Methods: Interviews were carried out in 187 towns and villages in Sicily between 2005 and 2015. A total of 980 people over the age of 50 were interviewed (mainly farmers, shepherds, and experts on local traditions). Plants recorded were usually collected in collaboration with the informants to confirm the correct identification of the plants. The frequencies of citation were calculated. Results: Two hundred fifty-three taxa (specific and intraspecific) belonging to 39 families, and 128 genera were recorded (26 were cited for the first time). The most represented families were Asteraceae, Brassicaceae, Apiaceae, Amaryllidaceae, Malvaceae, and Polygonaceae. Only 14 taxa were cited by 75% of the people interviewed. The aerial parts of wild plants, including leaves, tender shoots, and basal rosettes, are the main portions collected, while the subterranean parts are used to a lesser extent. For some vegetables, more parts are utilized. Most of the reported vegetables are consumed cooked. In addition to the widely known vegetables (Borago officinalis, Beta spp., Cichorium spp., Brassica spp., Carduus spp., etc.), the so-called ancient vegetables are included (Onopordum illyricum, Centaurea calcitrapa, Nasturtium officinale, Scolymus spp., Smyrnium rotundifolium), and some unique uses were described. Comparing the Sicilian findings to those from other countries, a very high number of vegetable taxa were detected, 72 of which are eaten only in Sicily, while 12 are consumed in all the Mediterranean countries examined. Conclusions: The research shows a high level of Sicilian knowledge about using wild plants as a traditional food source. Wild vegetables are healthy and authentic ingredients for local and ancient recipes, which are fundamental to the revitalization of quality food strictly connected to traditional agroecosystems

    Aggregating Local Descriptors for Epigraphs Recognition

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    In this paper, we consider the task of recognizing epigraphs in images such as photos taken using mobile devices. Given a set of 17,155 photos related to 14,560 epigraphs, we used a k-NearestNeighbor approach in order to perform the recognition. The contribution of this work is in evaluating state-of-the-art visual object recognition techniques in this specific context. The experimental results conducted show that Vector of Locally Aggregated Descriptors obtained aggregating SIFT descriptors is the best choice for this task.The Fourth International Conference on Digital Presentation and Preservation of Cultural and Scientific Heritage—DiPP2014 is supported by the Ministry of Education and Science and is under the patronage of UNESCO
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