3,449 research outputs found

    Honeypot-powered Malware Reverse Engineering

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    Honeypots, i.e. networked computer systems specially designed and crafted to mimic the normal operations of other systems while capturing and storing information about the interactions with the world outside, are a crucial technology into the study of cyber threats and attacks that propagate and occur through networks. Among them, high interaction honeypots are considered the most efficient because the attacker (whether automated or not) perceives realistic interactions with the target machine. In the case of automated attacks, propagated by malwares, currently available honeypots alone are not specialized enough to allow the analysis of their behaviors and effects on the target system. The research presented in this paper shows how high interaction honeypots can be enhanced by powering them with specific features that improve the reverse engineering activities needed to effectively analyze captured malicious entities

    Environmental Noise and Nonlinear Relaxation in Biological Systems

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    We analyse the effects of environmental noise in three different biological systems: (i) mating behaviour of individuals of \emph{Nezara viridula} (L.) (Heteroptera Pentatomidae); (ii) polymer translocation in crowded solution; (iii) an ecosystem described by a Verhulst model with a multiplicative L\'{e}vy noise.Comment: 32 pages; In "Ecological Modeling" by Ed. Wen-Jun Zhang. ISBN: 978-1-61324-567-5. - Nova Science Publishers, New York, 201

    Noise Induced Phenomena in the Dynamics of Two Competing Species

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    Noise through its interaction with the nonlinearity of the living systems can give rise to counter-intuitive phenomena. In this paper we shortly review noise induced effects in different ecosystems, in which two populations compete for the same resources. We also present new results on spatial patterns of two populations, while modeling real distributions of anchovies and sardines. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. We find noise induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise delayed extinction, and noise induced pattern formation. In addition, our theoretical results are validated with experimental findings. Specifically the results, obtained by a coupled map lattice model, well reproduce the spatial distributions of anchovies and sardines, observed in a marine ecosystem. Moreover, the experimental dynamical behavior of two competing bacterial populations in a meat product and the probability distribution at long times of one of them are well reproduced by a stochastic microbial predictive model.Comment: 23 pages, 8 figures; to be published in Math. Model. Nat. Phenom. (2016

    Enhanced relativistic-electron beam collimation using two consecutive laser pulses

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    The double laser pulse approach to relativistic electron beam (REB) collimation has been investigated at the LULI-ELFIE facility. In this scheme, the magnetic field generated by the first laser-driven REB is used to guide a second delayed REB. We show how electron beam collimation can be controlled by properly adjusting laser parameters. By changing the ratio of focus size and the delay time between the two pulses we found a maximum of electron beam collimation clearly dependent on the focal spot size ratio of the two laser pulses and related to the magnetic field dynamics. Cu-K alpha and CTR imaging diagnostics were implemented to evaluate the collimation effects on the respectively low energy ( MeV) components of the REB

    Conceptual design of electron beam diagnostics for high brightness plasma accelerator

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    A design study of the diagnostics of a high brightness linac, based on X-band structures, and a plasma accelerator stage, has been delivered in the framework of the EuPRAXIA@SPARC_LAB project. In this paper, we present a conceptual design of the proposed diagnostics, using state of the art systems and new and under development devices. Single shot measurements are preferable for plasma accelerated beams, including emittance, while μ\mum level and fs scale beam size and bunch length respectively are requested. The needed to separate the driver pulse (both laser or beam) from the witness accelerated bunch imposes additional constrains for the diagnostics. We plan to use betatron radiation for the emittance measurement just at the end of the plasma booster, while other single-shot methods must be proven before to be implemented. Longitudinal measurements, being in any case not trivial for the fs level bunch length, seem to have already a wider range of possibilities

    Compartimentação topossequencial e caracterização fitossociológica de um capão de Floresta Ombrófila Mista.

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    Este trabalho teve como objetivo caracterizar a composição e estrutura florística de um capão de floresta no município de Quatro Barras, inserido em Estepe do Primeiro Planalto Paranaense, relacionando relevo e solos. Com base na definição de compartimentos no ambiente, que considerou as formas e declividades das rampas e as características dos solos, foram instaladas parcelas para amostragem das árvores. As espécies responderam em diversidade e densidade às diferentes condições de drenagem dos Cambissolos e Gleissolos do capão. Podocarpus lambertii demonstrou elevada adaptabilidade a solos com diferentes regimes de saturação hídrica, enquanto Myrcia laruotteana apresentou relação estreita com solos saturados hidricamente. A compartimentação ambiental com base em geomorfologia e solos mostrou ser um quesito fundamental para a melhor compreensão da distribuição das espécies vegetais na paisagem

    Recuperação ambiental em áreas de estepe do Primeiro Planalto Paranaense, mediante plantio de espécies arbóreas.

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    A diversidade e a intensidade das atividades antrópicas implicam em grandes impactos sobre a vegetação, alterando sua florística, estrutura e funções. A Floresta Ombrófila Mista, assim como as estepes, estão fortemente descaracterizadas, tendo essas últimas poucas e incipientes informações sobre recuperação ambiental. Às margens da represa do Iraí (Região Metropolitana de Curitiba, PR), em área de estepe associada à Floresta Ombrófila Mista, foram realizados plantios com espécies arbóreas como forma de dar início à reconstituição da flora arbórea perdida em decorrência do alagamento. Em meio a esses, foi instalado um experimento com o objetivo de avaliar o crescimento e a sobrevivência de oito espécies arbóreas nativas da região, aos 12 meses, estabelecidas em parcelas monoespecíficas e sob mesmas condições ambientais. Os dados de Escallonia montevidensis, Lafoensia pacari, Lithraea molleoides, Luehea divaricata, Mimosa scabrella, Podocarpus lambertii e Vitex megapotamica foram insatisfatórios, com alturas q ue variaram de 10 a 33 cm, diâmetro de colo entre 2,5 a 6,6 mm e sobrevivência entre 9,1 a 66, 7 %. Atribuíram-se esses resultados a hipóteses como déficit hídrico, solos com dessaturação por bases, época de plantio tardia e evapotranspiração intensificada. Em ações de recuperação ambiental, é necessário considerar os limites e possibilidades referentes à cada unidade fitoecológica e às técnicas de recuperação.Nota Científica
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