Flexible Management on BSP Process Rescheduling: Offering Migration at Middleware and Application Levels

This article describes the rationales for developing jMigBSP - a Java programming library that offers object rescheduling. It was designed to work on grid computing environments and offers an interface that follows the BSP (Bulk Synchronous Parallel) style. jMigBSP’s main contribution focuses on the rescheduling facility in two different ways: (i) by using migration directives on the application coded irectly and (ii) through automatic load balancing at middleware level. Especially, this second idea is feasible thanks to the Java’s inheritance feature, in which transforms a simple jMigBSP application in amigratable one only by changing a single line of code. In addition, the presented library makes the object interaction easier by providing one-sided message passing directives and hides network latency through asynchronous communications. Finally, we developed three BSP applications: (i) Prefix Sum; (ii) Fractal Image Compression (FIC) and; (iii) Fast Fourier Transform (FFT).They show our library as viable solution to offer load balancing on BSP applications. Specially, the FIC results present gains up to 37% when applying migration directives inside the code. Finally, the FFT tests emphasize strength of jMigBSP. In this situation, it outperforms a native library denoted BSPlib when migration facilities take place.Keywords: Bulk Synchronous Parallel, rescheduling, Java, adaptation, object migration, grid computing

Organic Livestock Production- A Bibliometric Review

Due to the increasing interest in organic farming, an overview of this research area is provided through a bibliometric analysis conducted between April and May 2019. A total of 320 documents were published up until 2018 on organic livestock farming, with an annual growth rate of 9.33% and a clear increase since 2005; 268 documents have been published in 111 journals. Germany is the country with the largest number of published papers (56 documents). Authors\u2019 top keywords (excluding keywords used for running the search) included: animal welfare (29 times), animal health (22 times), cattle (15 times), grazing (10 times), and sheep (10 times). This could indicate that more research has been done on cattle because of the importance of this species in Germany. Moreover, the prevalence of the terms \u2018animal welfare\u2019 and \u2018animal health\u2019 may indicate that the research on organic livestock production has been focused on these two areas. The bibliometric analysis indicates that: i) countries focused the organic livestock production research on their main production, and ii) more research in species other than cattle and sheep is needed

Análise de desempenho financeiro setorial no mercado brasileiro

<div align="justify">O presente trabalho tem como objetivo auferir quais dos setores pertencentes àBM&F/Bovespa (Telecomunicações, Energia Elétrica, Industrial, Consumo,Imobiliário e Financeiro) possui o melhor desempenho. Para tanto são utilizadosindicadores referenciados na literatura de finanças (Índice de Sharpe, Índice deSortino, Índice de Treynor, Alfa de Jensen, Medida de Modigliani e Modigliani eÍndice de Informação). A amostra é composta por 812 observações (02/01/2007 a19/04/2010). Os resultados obtidos permitem concluir que o setor de Energia Elétricaobteve o melhor desempenho no período amostral estudado, sendo, dentre osíndices setoriais da BM&F/Bovespa, o mais indicado para diversos tipos decomposição, seja uma carteira inteira, uma fração da mesma ou diversificação.<br><br>Abstract The present paper aims ascertain which sectors of the BM&F/Bovespa(Telecommunications, Electric Energy, Industrial, Consumption, Real Estate andFinancial) has the best performance. For this are used indicators referenced in thefinance literature (Sharpe Index, Sortino Index, Treynor Index, Jensen's Alpha,Modigliani and Modigliani Measure and Information Index). The sample is composedfor 812 observations (2007/01/02 to 2010/04/19). The results obtained allowconcluding that the sector of Electric Energy obtained the best performance in thesample period studied, and, among the sectorial indices of the BM&F/Bovespa, the most suitable for various kinds of composition, it is entire portfolio, a fraction of thesame or diversification.</div

P2P-role: uma arquitetura de controle de acesso baseada em papéis para sistemas colaborativos peer-to-peer

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Os sistemas Peer-to-Peer apresentam uma forma de computação distribuída onde cada participante atua como cliente e servidor de recursos. Entre os principais desafios existentes nesse tipo de computação, estão o desenvolvimento de técnicas para incentivar a colaboração entre os usuários e a proteção dos elementos e informações localizados no ambiente Peer-to-Peer. Este documento define uma arquitetura de controle de acesso baseada em papes específica para as redes Peer-to-Peer e busca, assim, contribuir para a construção de sistemas colaborativos mais robustos e seguros. Também são exploradas as relações entre o controle de acesso e as técnicas utilizadas para estimular a cooperação entre os integrantes da rede Peer-to-Peer. Pretende-se, dessa forma, que a arquitetura de controle de acesso definida também auxilie para minimizar a quantidade de nós que não colaboram com rede e que apenas sugam seus recursos. O protótipo implementado baseia-se nas tecnologias JXTA e P2PSockets e provê meios para que cada nó da rede P2P gerencia a política de segurança de seus recursos

Spots of interaction: an investigation on the relationship between firms and universities in Minas Gerais, Brazil

Spots of interaction summarize the nature of partial connections (between science and technology) operating in the Brazilian system of innovation. A pilot study in Minas Gerais, Brazil, uses two new research tools (for immature NSIs) and presents a database with research groups located in universities and a database built upon an adapted version of the pioneering Yale and Carnegie Mellon Surveys. These complementary databases identify spots of interaction, indicating how economic sectors use specific science and engineering fields. This investigation identifies a dual role of universities in immature NSIs, as substitutes and/or complements firms R&D.systems of innovation, underdevelopment, interactions between science and technology, surveys, universities

Elasticidade em cloud computing: conceito, estado da arte e novos desafios

A elasticidade é sem dúvida uma das características mais marcantes da computação em nuvem, sendo um diferencial desse tipo de sistema distribuído em relação a outros como grades computacionais e peer-to-peer. Com base nos paradigmas de computação sobre demanda e pague-pelo-que-use, é possível dinamicamente aumentar ou diminuir instâncias de máquinas virtuais e/ou nós de computação, bem como aplicar reconfigurações de percentagem de CPU, memória e largura de banda de rede relativos a um serviço em nuvem. Além dos evidentes benefícios de custo e desempenho para o usuário, o provedor da nuvem também tem a vantagem de oferecer um melhor uso dos recursos perante seus usuários. Nesse contexto, esse artigo apresenta o estado-da-arte na área de elasticidade em nuvem, enfatizando desde a abordagem padrão que usa transações Web até iniciativas para a computação de alto desempenho. Ainda, o artigo discute sobre métricas para ativação da elasticidade, o seu nível de atuação (SaaS, PaaS ou IaaS), bem como a interface de uso (sem intervenção do usuário, linha de comando, ferramenta gráfica ou diretivas de programação). Para fins de experimentação, um estudo de caso do emprego da elasticidade em aplicações de alto desempenho sobre o middleware OpenNebula é apresentado e discutido. Por fim, o artigo aponta os desafios na área e oportunidades de pesquisa, tanto no cunho das nuvens privadas quanto públicas

Barchan dunes cruising dune-size obstacles

We investigate the behavior of subaqueous barchans reaching dune-size obstacles by carrying out experiments where we varied the obstacle shape and size, the flow strength, and the grains' properties. We found that a subaqueous barchan can pass over or bypass a dune-size obstacle, or even be blocked, with some intermediate situations. In the bypass cases, the original barchan can split in two or more bedforms, redistributing sand in space. Finally, we propose a classification map in which the barchan behavior depends basically on two dimensionless parameters. Our results represent a step toward understanding how barchans behave in the presence of large obstacles, such as retaining walls, tubes and bridge pillars.Comment: Published under the CC BY 4.0 license. To view open-access paper, go to https://doi.org/10.1029/2023GL10412

Extension of analytical indicial aerodynamics to generic trapezoidal wings in subsonic flow

Analytical indicial aerodynamic functions are calculated for several trapezoidal wings in subsonic flow, with a Mach number 0.3≤ Ma≤ 0.7. The formulation herein proposed extends well-known aerodynamic theories, which are limited to thin aerofoils in incompressible flow, to generic trapezoidal wing planforms. Firstly, a thorough study is executed to assess the accuracy and limitation of analytical predictions, using unsteady results from two state-of-the-art computational fluid dynamics solvers as cross-validated benchmarks. Indicial functions are calculated for a step change in the angle of attack and for a sharp-edge gust, each for four wing configurations and three Mach numbers. Then, analytical and computational indicial responses are used to predict dynamic derivatives and the maximum lift coefficient following an encounter with a one-minus-cosine gust. It is found that the analytical results are in excellent agreement with the computational results for all test cases. In particular, the deviation of the analytical results from the computational results is within the scatter or uncertainty in the data arising from using two computational fluid dynamics solvers. This indicates the usefulness of the developed analytical theories