351 research outputs found

    EPOBF: Energy Efficient Allocation of Virtual Machines in High Performance Computing Cloud

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    Cloud computing has become more popular in provision of computing resources under virtual machine (VM) abstraction for high performance computing (HPC) users to run their applications. A HPC cloud is such cloud computing environment. One of challenges of energy efficient resource allocation for VMs in HPC cloud is tradeoff between minimizing total energy consumption of physical machines (PMs) and satisfying Quality of Service (e.g. performance). On one hand, cloud providers want to maximize their profit by reducing the power cost (e.g. using the smallest number of running PMs). On the other hand, cloud customers (users) want highest performance for their applications. In this paper, we focus on the scenario that scheduler does not know global information about user jobs and user applications in the future. Users will request shortterm resources at fixed start times and non interrupted durations. We then propose a new allocation heuristic (named Energy-aware and Performance per watt oriented Bestfit (EPOBF)) that uses metric of performance per watt to choose which most energy-efficient PM for mapping each VM (e.g. maximum of MIPS per Watt). Using information from Feitelson's Parallel Workload Archive to model HPC jobs, we compare the proposed EPOBF to state of the art heuristics on heterogeneous PMs (each PM has multicore CPU). Simulations show that the EPOBF can reduce significant total energy consumption in comparison with state of the art allocation heuristics.Comment: 10 pages, in Procedings of International Conference on Advanced Computing and Applications, Journal of Science and Technology, Vietnamese Academy of Science and Technology, ISSN 0866-708X, Vol. 51, No. 4B, 201

    Sentiment classification of consumer generated online reviews using topic modeling

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    The development of the Internet and mobile devices enabled the emergence of travel and hospitality review sites, leading to a large number of customer opinion posts. While such comments may influence future demand of the targeted hotels, they can also be used by hotel managers to improve customer experience. In this article, sentiment classification of an eco-hotel is assessed through a text mining approach using several different sources of customer reviews. The latent Dirichlet allocation modeling algorithm is applied to gather relevant topics that characterize a given hospitality issue by a sentiment. Several findings were unveiled including that hotel food generates ordinary positive sentiments, while hospitality generates both ordinary and strong positive feelings. Such results are valuable for hospitality management, validating the proposed approach.info:eu-repo/semantics/acceptedVersio

    HPC Cloud for Scientific and Business Applications: Taxonomy, Vision, and Research Challenges

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    High Performance Computing (HPC) clouds are becoming an alternative to on-premise clusters for executing scientific applications and business analytics services. Most research efforts in HPC cloud aim to understand the cost-benefit of moving resource-intensive applications from on-premise environments to public cloud platforms. Industry trends show hybrid environments are the natural path to get the best of the on-premise and cloud resources---steady (and sensitive) workloads can run on on-premise resources and peak demand can leverage remote resources in a pay-as-you-go manner. Nevertheless, there are plenty of questions to be answered in HPC cloud, which range from how to extract the best performance of an unknown underlying platform to what services are essential to make its usage easier. Moreover, the discussion on the right pricing and contractual models to fit small and large users is relevant for the sustainability of HPC clouds. This paper brings a survey and taxonomy of efforts in HPC cloud and a vision on what we believe is ahead of us, including a set of research challenges that, once tackled, can help advance businesses and scientific discoveries. This becomes particularly relevant due to the fast increasing wave of new HPC applications coming from big data and artificial intelligence.Comment: 29 pages, 5 figures, Published in ACM Computing Surveys (CSUR

    Programa de microcomputador, em linguagem Basic, para o dimensionamento de canais de irrigação.

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    bitstream/item/65886/1/CPAO-DOC.-24-86.pd

    Floating islands implementation in marine and freshwater environments

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    Rapid industrialization, changes in human activities, and agricultural practices have led to the widespread use of toxic organic compounds, resulting in increased concentrations of pollutants in the environment that can be transmitted through air, water, or soil, resulting in numerous environmental and health problems. Therefore, the efficient management of water in these polluted sites is urgently needed. Aiming at this, this work proposes the use of floating wetland islands (FWI) for phytoremediation of these environments, since they have a great potential to promote several ecosystem services, such as biodiversity and water quality improvement. Having that in consideration it will be carried out an assessment related to the most adequate materials for the floating platform to be applied in marine and freshwater environments. Plants will be selected based on previous research carried out by the group It is intended that the floating platform developed under the present study will be compared with a commercial system cork based. It will be monitored the plant development and establishment in the two floating platforms materials and environments, the associated fauna and the water characterization. From the analysis of these results, this work hopes that these nature-based solutions can contribute to better water management, in such a way that will involve the conservation and rehabilitation of ecosystems.info:eu-repo/semantics/publishedVersio

    Eco-agricultura: um modelo para a sustentabilidade que o Brasil precisa?

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    bitstream/item/79997/1/ADM132.pdfFormato eletrônico. Disponível também em: MS noticias, AgoraMS, ZooNews, BBC News, Sustentabilidade.blog.br, Infobibos, Portal Bonito, Naviraí Notícias, Grupo Cultivar, Portal Dia de Campo

    Biodiversity associated to a floating wetland island in a freshwater pond

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    Floating wetland islands (FWI) are considered nature-based solutions that can be applied in different water bodies, such as lakes and rivers, in order to deliver a wide range of ecosystem services. They are recognized to promote local biodiversity, aesthetic integration and provide water quality enhancement through phytoremediation processes, although research is still needed to go deeper on the processes underlying the performance of these systems. The aim of this study was to assess de biodiversity associated to a FWI made of cork agglomerate, set up in 2018 in a freshwater pond. A polyculture comprising the plant species Iris germanica, Acorus gramineus, Caltha palustris, and Typha latifolia was considered. The culturable bacterial communities associated to the floating platform biofilm and to the plant rhizosphere were analyzed. The bacterial isolates were identified by 16S rRNA and characterized for their ability to produce plant growth promoting substances (e.g., indole-acetic acid, siderophores). The diversity of macroinvertebrates associated to FWI was also assessed. Water analysis of the pond were conducted. Preliminary data shows that there is a high bacterial diversity associated to this system and the ability to produce plant growth promoting substances has been shown. The bacterial strains with outstanding growth promoting traits can be used in the future to support phytoremediation strategies or plant resilience to climate change abiotic stresses. Regarding the biodiversity of macroinvertebrates associated with FWI they were mainly from the order Odonata. The FWI attracted mainly individuals of the genus Coenagrion (represented more than 80% of the fauna). These systems had proven to be a hotspot of biodiversity supporting water management plans and landscape and aesthetics integration. This study gives new insights into broadening the FWI applications in freshwater or polluted water.info:eu-repo/semantics/publishedVersio

    Determinação da evapotranspiração potencial decendial de Dourados, MS, por meio de métodos indiretos.

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