Relating L-Resilience and Wait-Freedom via Hitting Sets

The condition of t-resilience stipulates that an n-process program is only obliged to make progress when at least n-t processes are correct. Put another way, the live sets, the collection of process sets such that progress is required if all the processes in one of these sets are correct, are all sets with at least n-t processes. We show that the ability of arbitrary collection of live sets L to solve distributed tasks is tightly related to the minimum hitting set of L, a minimum cardinality subset of processes that has a non-empty intersection with every live set. Thus, finding the computing power of L is NP-complete. For the special case of colorless tasks that allow participating processes to adopt input or output values of each other, we use a simple simulation to show that a task can be solved L-resiliently if and only if it can be solved (h-1)-resiliently, where h is the size of the minimum hitting set of L. For general tasks, we characterize L-resilient solvability of tasks with respect to a limited notion of weak solvability: in every execution where all processes in some set in L are correct, outputs must be produced for every process in some (possibly different) participating set in L. Given a task T, we construct another task T_L such that T is solvable weakly L-resiliently if and only if T_L is solvable weakly wait-free

Comparison Of Anisotropy Reduction Strategies For Transformation Optics Designs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this paper, we present new strategies to reduce anisotropy in transformation optics designs and compare them to other techniques. Perturbation functions are used to modify the original transformation to achieve a quasi-conformal map, resulting in a medium with isotropic properties. All strategies investigated have no effect on the original boundary conditions of the transformation, such that neither the initial design is affected nor are reflections at the boundaries introduced. The results show that there exists a clear compromise between the residual anisotropy and the required refractive index contrast in the optimized transformation, but the former can be made as small as desired when the degree of freedom provided by perturbation functions is increased, although it is never exactly zero.71Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Controle de cancro-do-enxerto (Lasiodiplodia theobromae (Pat) Griff & Maubl em seringueira utilizando-se a técnica do plantio profundo.

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Qual é sua pegada?: o reflexo de seu consumo.

Pegada Ecológica. Consumo versus produção de lixo. O que são materiais recicláveis e não recicláveis. Resíduos recicláveis. Resíduos não recicláveis. Resíduos orgânicos. Resíduos químicos ou tóxicos. Resíduos potencialmente perigosos. Como contribuir para o equilíbrio do ambiente em que vivemos?. Curiosidades. Teste: Quanto você pesa para o planeta?. Fluxograma de gerenciamento dos resíduos gerais da Embrapa Arroz e Feijão. Canecas versus copos descartáveis. Colabore para uma empresa ambientalmente responsável.bitstream/CNPAF-2010/29764/1/doc-245.pd

Avaliação da qualidade dos produtos, infraestrutura e serviços em feiras e mercados orgânicos localizados em Brasília ? DF.

É notório que o interesse em formas de produção consideradas alternativas se intensificou, visando atender à crescente demanda pelos produtos saudáveis e sustentáveis. O presente estudo tem como eixo principal as feiras locais e um mercado de produtos orgânicos. O objetivo foi avaliar a percepção dos feirantes e produtores sobre a qualidade dos produtos, a infraestrutura e os serviços prestados por estes estabelecimentos em Brasília-DF. Para obtenção dos dados foram realizadas entrevistas com feirantes guiadas pelo uso de questionário. Verificou-se que a maioria dos feirantes tem renda exclusivamente da venda da produção orgânica. Quanto à qualidade do produto, esses profissionais julgam importante a higienização e cuidados para manter a boa aparência do alimento. Atenção e cordialidade foram consideradas atributos muito importantes, na percepção dos feirantes, na relação dos mesmos com a clientela para manter a fidelidade. Abstract: It?s well known that the interest in alternative forms of production have intensified, in order to attend the growing market demand for healthier and sustainable products. As the main axis of this study, local fairs and organic market were considered. The objective was to evaluate those fair workers and producer?s perception towards the product?s quality, the local infrastructure and the establishment?s services. Data collection was performed by interviews guided by a questionnaire application. The results show that the majority of workers have incomes exclusively from the sale of organic production. Regarding product?s quality, these professionals consider as important the product?s sanitization and the care to maintain the product?s good appearance. Attention and cordiality were considered very important for fair workers in their relationship with consumers to maintain fidelity

New diseases caused by virus, fungi and also a bacterium on rubber from Brazil and their impact on international quarantine.

More recently, leaf diseases attributable to virus, other fungi and possibly a bacterium were well recorded as a new disase of the rubber tree. In the state of Amazonas, symptoms of a systemic infection caused by virus (being identified), typified by leaf mosaic, little leaf, malformation and tree stunt were confirmed in clonal nurseries and field plantings in several clones at CNPSD. In tests, the symptoms of virus appeared more distinct at temperatures below 22oC. The new fungal leaf pathogens discovered in the nurseries and fields are Corynespora cassiicola, Periconia manihoticola (previously of minor importance), and an Ascomycete (Dothideaceae) in association with Phyllachora huberi yet to be identified. Also discovered were leaf symptoms in the form of tiny lesions, followed by premature leaf yellowing and fall, suggestive of a bacterial infection. These were reproduced in artificial inoculation with a culture of the bacterium repeatedly isolated from fields of clones Fx 3864, PFB 5, IAN 873 and PA 31. Relating these potentially dangerous new diseases to the welll-being of the rubber industry worldwide, international quarantine measures adopted today against Microcyclus ulei alone must now be reviewed. These should include additional measures for the inspection, identification and preventive pre and postquarantine treatment against the virus, bacterium and hitherto unknown fungi