270 research outputs found

    Finding Best Compiler Options for Critical Software Using Parallel Algorithms

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    The efficiency of a software piece is a key factor for many systems. Real-time programs, critical software, device drivers, kernel OS functions and many other software pieces which are executed thousands or even millions of times per day require a very efficient execution. How this software is built can significantly affect the run time for these programs, since the context is that of compile-once/run-many. In this sense, the optimization flags used during the compilation time are a crucial element for this goal and they could make a big difference in the final execution time. In this paper, we use parallel metaheuristic techniques to automatically decide which optimization flags should be activated during the compilation on a set of benchmarking programs. The using the appropriate flag configuration is a complex combinatorial problem, but our approach is able to adapt the flag tuning to the characteristics of the software, improving the final run times with respect to other spread practicesThis research has been partially funded by the Spanish MINECO and FEDER projects (TIN2014-57341-R (http://moveon.lcc.uma.es), TIN2016-81766-REDT (http://cirti.es), and TIN2017-88213-R (http://6city.lcc.uma.es). It is also funded by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Interpretative flexibility and conflicts in the emergence of Mobility as a Service : Finnish public sector actor perspectives

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    Mobility-as-a-service (MaaS) is still largely under development, with high uncertainties of its societal implications. This development is happening across sectoral, multi-layered, and multi-actor networks. Previous case studies on understanding networked governance of MaaS inform us that there is a range of challenges in the current institutional arrangements, lack of shared MaaS vision, divergent interests, and even conflicts over roles and responsibilities. These case studies have used analytical frameworks based on socio-technical transitions theory, complemented with theories from institutional and business studies. This study focuses on Finland, aiming to provide additional insights about perspectives of non-commercial actors. In particular, we provide a more sophisticated understanding of underlying reasons for conflict and lack of cooperation concerning an understanding of MaaS, its implications, and associated governance actions. The applied analytical framework is building upon concepts from the philosophy and sociology of emerging technology, as well as the contemporary political theory of Chantal Mouffe. Interview findings from seventeen non-commercial organisations have been classified into five categories, namely definitions, operational and business aspects, user perspectives, systemic effects, and governance. Discussion of these interview findings focuses on the interpretative flexibility of MaaS and governance processes in the context of inherent conflict in the value-laden mobility domain. The paper concludes with outlining directions for further synthesis in developing analytical frameworks for studies of governance and responsible innovation in the domain of emerging mobility technologies.Peer reviewe

    A critical evaluation of the usefulness of a coding scheme to categorise levels of reflective thinking

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    The use of reflective learning journals to encourage higher order learning outcomes is a growing area in higher education research and practice. However, without a unified and clear definition of reflection, identifying and assessing reflection is problematic for educators. In an attempt to address this issue Kember et al. (1999) devised a coding scheme based on the work of Mezirow (1991), to identify and assess levels of reflective thinking in students’ written journals. We evaluated the usefulness of this coding scheme in a business education context. Findings revealed that the scheme was useful in identifying categories of reflective thinking. Initial inter-coder agreement ranged from 50-79%. On average, 65% of the journal content was coded as non-reflection and 35% as reflection. A further outcome of the research was to refine the coding scheme and to provide suggestions for its application in teaching practice

    A MOS-based Dynamic Memetic Differential Evolution Algorithm for Continuous Optimization: A Scalability Test

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    Continuous optimization is one of the areas with more activity in the field of heuristic optimization. Many algorithms have been proposed and compared on several benchmarks of functions, with different performance depending on the problems. For this reason, the combination of different search strategies seems desirable to obtain the best performance of each of these approaches. This contribution explores the use of a hybrid memetic algorithm based on the multiple offspring framework. The proposed algorithm combines the explorative/exploitative strength of two heuristic search methods that separately obtain very competitive results. This algorithm has been tested with the benchmark problems and conditions defined for the special issue of the Soft Computing Journal on Scalability of Evolutionary Algorithms and other Metaheuristics for Large Scale Continuous Optimization Problems. The proposed algorithm obtained the best results compared with both its composing algorithms and a set of reference algorithms that were proposed for the special issue

    Alchemilla Vulgaris L. kao potencijalni izvor prirodnih antioksidanata

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    The aim of this study was to examine the total phenolic and flavonoid content, and antioxidant activity of the methanol extract of Alchemilla vulgaris aerial parts, as a potential source of natural antioxidants. The obtained results showed that extract has high total phenolic content (590,22 mg GAE/g), wheras flavonoid content was lower (12,58 mg RU/g). Antioxidant activity was determined in vitro by DPPH· and ABTS+· reagents. The IC50 values of DPPH (5,40 μg/ml) and ABTS+· scavenging capacities (60,10 μg/ml) of methanol extract showed that tested extract has extremely strong antioxidant activity.Cilj ovog rada je bio ispitivanje antioksidativne aktivnosti, kao i količine ukupnih fenolnih jedinjenja i flavonoida u metanolnom ekstraktu biljke A. vulgaris L., kao potencijalnog izvora prirodnih antioksidanata. Ispitivani ekstrakt poseduje visok sadržaj ukupnih fenola (590,22 mg GA/g), dok je koncentracija flavonoida znatno manja (12,58 mg RU/g). Antioksidativna aktivnost je ispitivana in vitro DPPH i ABTS+· metodom, a IC50 vrednosti ukazuju da ispitivani ekstrakt pokazuje izuzetno visok stepen antioksidativne aktivnosti u poređenju sa referentnim fenolnim jedinjenjima, što ukazuje na mogućnost primene ekstrakta A. vulgaris u prehrambenoj industriji

    Improving metaheuristic performance by evolving a variable fitness function.

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    In this paper we study a complex real world workforce scheduling problem. We apply constructive search and variable neighbourhood search (VNS) metaheuristics and enhance these methods by using a variable fitness function. The variable fitness function (VFF) uses an evolutionary approach to evolve weights for each of the (multiple) objectives. The variable fitness function can potentially enhance any search based optimisation heuristic where multiple objectives can be defined through evolutionary changes in the search direction. We show that the VFF significantly improves performance of constructive and VNS approaches on training problems, and ¿learn¿ problem features which enhance the performance on unseen test problem instances

    Stabilnost ekstrakta korena suručice i efekat na sprečavanje lipidne oksidacije u mesu

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    Nowadays, consumers are demanding more natural foods, obliging the industry to include natural antioxidants in foods and synthetic antioxidants have been rejected because of their carcinogenicity. Natural antioxidants have been used instead of synthetic to retard lipid oxidation in foods to improve their quality and nutritional value. The aim of this work was to evaluate pH and termal stability, and effect on lipid oxidation in meat-model system of methanolic extract of Filipendula hexapetala Gilib. Results suggest that the stability of the extract is expressed in a variety of pH and thermal conditions. The root extract of F. hexapetala exerted a concentration-dependent antioxidant activity in a meat model system, lower than synthetic antioxidant BHT.Danas je u ishrani zastupljen veliki broj prirodnih proizvoda, tako da prehrambena industrija sve više koristi prirodne antioksidante, a sintetički antioksidanti se izbacuju iz upotrebe zbog njihove kancerogenosti. Prirodni antioksidanti se koriste umesto sintetičkih da uspore oksidaciju lipida, poboljšaju kvalitet i nutritivnu vrednost namirnica. Cilj ovog rada bio je određivanje pH i termalne stabilnosti, kao i efekta na lipidnu oksidaciju u mesu metanolskog ekstrakta korena biljke Filipendula hexapetala Gilib. Rezultati ukazuju da je stabilnost ekstrakta izražena u različitim pH i termalnim uslovima. Ekstrakt korena F. hexapetala pokazao je koncentraciono-zavisnu antioksidativnu aktivnost u meso model-sistemu, nešto nižu u odnosu na sintetički antioksidant BHT

    Involvement of proteasome activation

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    Alzheimer's disease (AD) is the most common form of dementia worldwide, characterized by a progressive decline in a variety of cognitive and non-cognitive functions. The amyloid beta protein cascade hypothesis places the formation of amyloid beta protein aggregates on the first position in the complex pathological cascade leading to neurodegeneration, and therefore AD might be considered to be a protein-misfolding disease. The Ubiquitin Proteasome System (UPS), being the primary protein degradation mechanism with a fundamental role in the maintenance of proteostasis, has been identified as a putative therapeutic target to delay and/or to decelerate the progression of neurodegenerative disorders that are characterized by accumulated/aggregated proteins. The purpose of this study was to test if the activation of proteasome in vivo can alleviate AD pathology. Specifically by using two compounds with complementary modes of proteasome activation and documented antioxidant and redox regulating properties in the 5xFAD transgenic mice model of AD, we ameliorated a number of AD related deficits. Shortly after proteasome activation we detected significantly reduced amyloid-beta load correlated with improved motor functions, reduced anxiety and frailty level. Essentially, to our knowledge this is the first report to demonstrate a dual activation of the proteasome and its downstream effects. In conclusion, these findings open up new directions for future therapeutic potential of proteasome-mediated proteolysis enhancement.publishersversionpublishe
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