211 research outputs found

    A polynomial-time branching procedure for the multiprocessor scheduling problem

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    In this paper, we present and analyze a branching procedure suitable for branchand-bound algorithms for solving multiprocessor scheduling problems. The originality of this branching procedure resides mainly in its ability to enumerate all feasible solutions without generating duplicated subproblems. This procedure is shown to be polynomial in time and space complexities. The main applications of such branching procedure are instances of the MSP where the costs are large because the height of the search tree is linear on the number of tasks to be scheduled. This in opposition to another branching procedure in the literature that generates a search tree whose height is porportional to the costs of the tasks

    Scheduling multiprocessor tasks with genetic algorithms

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    In the multíprocessor schedulíng problem a given program is to be scheduled in a given multiprocessor system such that the program 's execution time is minimized. This problem being very hard to solve exactly, many heuristic methods for finding a suboptimal schedule exist. We propose a new combined approach, where a genetic algorithm is improved with the introduction of some knowledge about the scheduling problem represented by the use of a list heuristic in the crossover and mutatíon genetic operations. This knowledge-augmented genetic approach is empirically compared with a "pure" genetic algorithm and with a "pure" list heuristic, both from the literature. Results of the experiments carried out with synthetic instances of the scheduling problem show that our knowledge-augmented algorithm produces much better results in terms of quality of solutions, although being slower in terms of execution time

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    A 5G-based authentication framework for V2X communication

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    The integration of Vehicle-to-everything (V2X) communication and Intelligent Transportation Systems (ITS) promises to revolutionize smart mobility. However, this technological advancement also exposes V2X networks to cybersecurity threats. To address these challenges, this work explores the critical security requirements for V2X communications, including User Equipment (UE) authorization, data integrity protection, and privacy support

    Metáfora: diferentes perspectivas

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    Effects of in vitro gastrointestinal digestion and colonic fermentation on a rosemary (Rosmarinus officinalis L) extract rich in rosmarinic acid

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    The potential phytochemical losses occurring throughout the sequential steps of in-vitro gastrointestinal digestion and colonic fermentation of a rosemary aqueous extract were investigated. Crude (CE), digested (DE) and fermented (FE) extracts were characterized in terms of their phenolic profile and biological activities. Rosmarinic acid was the phytochemical that underwent the most significate transformation during digestion and fermentation, which amounted to 60% compared to the 26% degradation of the total phenolics. Overall, the simulated digestion step decreased the antioxidant activity estimated by DPPH, ABTS, FRAP, ORAC and TBARS assays. Both CE and DE did not present antiproliferative potential, however, FE exhibited a pronounced cytotoxic activity (GI50 = 116 µg/mL) against HeLa cells. CE and DE showed to be moderate inhibitors of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), S. aureus, Listeria monocytogenes, whilst the FE acted as a moderate inhibitor of MRSA and MSSA.G.A. Gonçalves and V.G. Correa thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the financial support provided for their post-graduate studies in the State University of Maringá. R.C.G. Corrêa thanks Conselho Nacional de Desenvolvimento Científico e Tecnologia ( CNPq ) for financing her postdoctoral research at State University of Maringá (Process number 167378/2017-1). R.M. Peralta (Project number 307944/2015-8) and A. Bracht (Project number 304090/2016-6) are CNPq research grant recipients. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), L. Barros and R. Calhelha contracts; and also thank to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E. Appendix Ainfo:eu-repo/semantics/publishedVersio

    Soberania nacional, direitos humanos e o paradoxo democrático:: uma possível saída a partir das congruências entre Donatella Di Cesare, Michael Walzer e David Miller

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    This paper explores and recommends a way to overcome the democratic paradox, the fundamental moral dilemma between the national sovereignty of the liberal democratic State and the acknowledgment of the human rights of foreigners, highlighted by Donatella Di Cesare. This is achieved by reconstructing the paradox, based on the author's assessment of Michael Walzer and David Miller, and the solution she offers, which involves surpassing the state-centric order and creating a political community that is not dependent on national identity. Afterwards, the perspectives of these authors are scrutinized one by one to demonstrate that the criticisms raised by Di Cesare do not correspond to the works Walzer and Miller produced on political community and national identity. Lastly, we propose that there are commonalities between these three authors that could assist in the conceptual formulation of a concept of political community that can provide an initial answer to the democratic paradox.O artigo pretende analisar e sugerir uma saída para o paradoxo democrático, o dilema moral constitutivo entre a soberania nacional do Estado democrático liberal e o reconhecimento dos direitos humanos dos estrangeiros, apontado por Donatella Di Cesare. Para isso, serão reconstruídos o referido paradoxo, a partir das críticas da autora a Michael Walzer e David Miller, e a solução apontada por ela, que envolve a superação da ordem estadocêntrica e a criação de uma comunidade política que não seja centrada na identidade nacional. Em seguida, serão sucessivamente analisadas as posições de tais autores, mostrando-se que as críticas feitas por Di Cesare não correspondem aos trabalhos desenvolvidos por eles sobre comunidade política e identidade nacional. Por fim, será sugerido que há congruências entre esses três autores que poderiam ajudar na construção conceitual de um conceito de comunidade política capaz de oferecer uma direção inicial de saída do paradoxo democrático.O artigo pretende analisar e sugerir uma saída para o paradoxo democrático, o dilema moral constitutivo entre a soberania nacional do Estado democrático liberal e o reconhecimento dos direitos humanos dos estrangeiros, apontado por Donatella Di Cesare. Para isso, serão reconstruídos o referido paradoxo, a partir das críticas da autora a Michael Walzer e David Miller, e a solução apontada por ela, que envolve a superação da ordem estadocêntrica e a criação de uma comunidade política que não seja centrada na identidade nacional. Em seguida, serão sucessivamente analisadas as posições de tais autores, mostrando-se que as críticas feitas por Di Cesare não correspondem aos trabalhos desenvolvidos por eles sobre comunidade política e identidade nacional. Por fim, será sugerido que há congruências entre esses três autores que poderiam ajudar na construção conceitual de um conceito de comunidade política capaz de oferecer uma direção inicial de saída do paradoxo democrático

    By-products of camu-camu [Myrciaria dubia (Kunth) McVaugh] as promising sources of bioactive high added-value food ingredients: functionalization of yogurts

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    Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a fruit economically relevant to the Amazon region, mostly consumed in the form of processed pulp. Our aim was to perform an unprecedented comparative study on the chemical composition and bioactivities of the camu-camu pulp and industrial bio-residues (peel and seed), and then the most promising fruit part was further explored as a functionalized ingredient in yogurt. A total of twenty-three phenolic compounds were identified, with myricetin-O-pentoside and cyanindin-3-O-glucoside being the main compounds in peels, followed by p-coumaroyl hexoside in the pulp, and ellagic acid in the seeds. The peel displayed the richest phenolic profile among samples, as well as the most significant antibacterial (MICs = 0.625–10 mg/mL) and anti-proliferative (GI50 = 180 g/mL against HeLa cells) activities. For this reason, it was selected to be introduced in a food system (yogurt). Taken together, our results suggest the possibility of using the camu-camu peel as a source of food additives.Part of this work was supported by the Instituto Federal do Rondônia (IFRO) (Grant nº 81/PROPESP/IFRO). The authors are grateful to FCT—Portugal and FEDER, under Programme PT2020, for financial support to CIMO (UID/AGR/00690/2019) and B. Albuquerque research grant (SFRH/BD/136370/2018); national funding by FCT, P.I., through the institutional scientific employment program-contract for L. Barros and R.C. Calhelha contracts; C. Pereira contract though the celebration of program-contract foreseen in No. 4, 5, and 6 of article 23º of Decree-Law No. 57/2016, of 29 August, amended by Law No. 57/2017, of 19 July; to FEDER-Interreg España-Portugal for financial support through the projects 0377_Iberphenol_6_E and 0612_TRANS_CO_LAB_2_P; FEDER through the Regional Operational Program North 2020: project Mobilizador Norte-01-0247-FEDER-024479 (ValorNatural®).info:eu-repo/semantics/publishedVersio

    Phytochemicals and bioactive properties of Ilex paraguariensis: an in-vitro comparative study between the whole plant, leaves and stems

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    Leaves, stems and whole plant of Ilex paraguariensis (yerba mate) were characterized in terms of their chemical composition and biological activities in order to determine which part of the plant is more interesting to develop bioactive formulations. The yerba mate samples contain at least five free sugars, five organic acids, eighteen fatty acids, one tocopherol, nine hydroxycinnamoyl derivatives and two flavonols. The leaves extract revealed the highest antioxidant activity, correlating with its highest levels of phenolic compounds. By contrast, the stems extract showed the highest anti-inflammatory potential and was also the most potent against MCF-7 and HepG2 cell lines, probably due to the presence of other phytochemicals. The absence of hepatotoxicity of the extracts was confirmed in porcine liver primary cells. Although the yerba mate extracts have been widely studied, this report shows for the first time the distinct potentialities of each individual part of the plant.The authors are grateful to Foundation for Science and Technology (FTC, Portugal) for financial support to CIMO (Pest-OE/AGR/UI0690/2014), L. Barros research contract (“Compromisso para a Ciência”) and R.C. Calhelha grant (SFRH/BPD/68344/2010). R.C.G. Correa and A. H. P. Souza thank CAPES Foundation, Ministry of Education of Brazil (CAPES fellows, process numbers BEX 3974/14-6 and BEX 3972/14-03, respectively). The authors also thank to A. Fernandes for all the support in some of the laboratorial work
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