Beyond Counting: New Perspectives on the Active IPv4 Address Space

In this study, we report on techniques and analyses that enable us to capture Internet-wide activity at individual IP address-level granularity by relying on server logs of a large commercial content delivery network (CDN) that serves close to 3 trillion HTTP requests on a daily basis. Across the whole of 2015, these logs recorded client activity involving 1.2 billion unique IPv4 addresses, the highest ever measured, in agreement with recent estimates. Monthly client IPv4 address counts showed constant growth for years prior, but since 2014, the IPv4 count has stagnated while IPv6 counts have grown. Thus, it seems we have entered an era marked by increased complexity, one in which the sole enumeration of active IPv4 addresses is of little use to characterize recent growth of the Internet as a whole. With this observation in mind, we consider new points of view in the study of global IPv4 address activity. Our analysis shows significant churn in active IPv4 addresses: the set of active IPv4 addresses varies by as much as 25% over the course of a year. Second, by looking across the active addresses in a prefix, we are able to identify and attribute activity patterns to network restructurings, user behaviors, and, in particular, various address assignment practices. Third, by combining spatio-temporal measures of address utilization with measures of traffic volume, and sampling-based estimates of relative host counts, we present novel perspectives on worldwide IPv4 address activity, including empirical observation of under-utilization in some areas, and complete utilization, or exhaustion, in others.Comment: in Proceedings of ACM IMC 201

Aspectos biológicos de Acanthoscelides obtectus em diferentes temperaturas.

Acanthoscelides obtectus causa perdas qualitativas e quantitativas aos grãos do feijão, pois alimentam-se do endosperma e do embrião, reduzindo a massa da semente e favorecendo a entrada de microorganismos e ácaros. Neste trabalho, foi determinado o desenvolvimento biológico de A. obtectus em temperatura ambiente e a 16, 20, 24, 28 e 32° C.Resumo

GALERKIN FINITE ELEMENT METHOD AND FINITE DIFFERENCE METHOD FOR SOLVING CONVECTIVE NON-LINEAR EQUATION

The fast progress has been observed in the development of numerical and analytical techniques for solving convection-diffusion and fluid mechanics problems. Here, a numerical approach, based in Galerkin Finite Element Method with Finite Difference Method is presented for the solution of a class of non-linear transient convection-diffusion problems. Using the analytical solutions and the L2 and L∞ error norms, some applications is carried and valuated with the literature

Caracterização físico-química de mirtilos submetidos a diferentes coberturas de solo.

bitstream/item/79717/1/comunicado-266.pd

Stabilized least squares finite element method for 2D and 3D convection-diffusion

In this study, a computational code has been developed based into Finite Elements Method in the version of LSFEM (Least Squares Finite Element Method). The numeric development of this method has as a main advantage, the obtaining of an always symmetrical and defined positive algebraic system, independently of the considered partial-differential equation system. The computational code was applied in the solution of two-dimensional and three-dimensional convection-diffusion problems, through domain discretization of structured meshes of quadratic elements. Obtained numerical results showed a good concordance with available results, showing the developed model validity9455

Direct estimations of linear and non-linear functionals of a quantum state

We present a simple quantum network, based on the controlled-SWAP gate, that can extract certain properties of quantum states without recourse to quantum tomography. It can be used used as a basic building block for direct quantum estimations of both linear and non-linear functionals of any density operator. The network has many potential applications ranging from purity tests and eigenvalue estimations to direct characterization of some properties of quantum channels. Experimental realizations of the proposed network are within the reach of quantum technology that is currently being developed.Comment: This paper supersedes the paper quant-ph/0112073, titled "Universal Quantum Estimator". We emphasise the estimation of linear and non-linear functionals of a quantum stat

NUMERICAL SIMULATION OF INCOMPRESSIBLE FLOWS BY THE STABILIZED FINITE ELEMENT METHOD

The fast progress has been observed in the development of numerical and analytical techniques for solving convection-diffusion and fluid mechanics problems. Here, a numerical approach, based in Galerkin Finite Element Method with Finite Difference Method is presented for the solution of a class of non-linear transient convection-diffusion problems. Using the analytical solutions and the L2 and L∞ error norms, some applications is carried and valuated with the literature

Modelagem da hidrografia em planos de manejo e critérios para definição de árvores em APP pelo Modeflora.

Novas tecnologias, sendo advindas do geoprocessamento e do sensoriamento remoto, vêm sendo desenvolvidas a fim de auxiliar no processo de delimitação das APPs e demarcação das árvores. No entanto, faltam estudos para investigar e comprovar sua eficácia. Não há registro de trabalhos, publicados no Brasil, que utilizem diferentes metodologias na definição de APPs para avaliá-las. O presente trabalho teve como objetivo propor uma metodologia precisa para o mapeamento de áreas de preservação permanente e definição de árvores protegidas e exploráveis na região de influência das APPs, comprovando a sua aplicabilidade nos PMFS.bitstream/CPAF-AC-2010/23132/1/circtec-n50.pd

Structural properties of crumpled cream layers

The cream layer is a complex heterogeneous material of biological origin which forms spontaneously at the air-milk interface. Here, it is studied the crumpling of a single cream layer packing under its own weight at room temperature in three-dimensional space. The structure obtained in these circumstances has low volume fraction and anomalous fractal dimensions. Direct means and noninvasive NMR imaging technique are used to investigate the internal and external structure of these systems.Comment: 9 pages, 4 figures, accepted in J. Phys. D: Appl. Phy