1,561 research outputs found

    Using smartphones as a proxy for forensic evidence contained in cloud storage services

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    Cloud storage services such as Dropbox, Box and SugarSync have been embraced by both individuals and organizations. This creates an environment that is potentially conducive to security breaches and malicious activities. The investigation of these cloud environments presents new challenges for the digital forensics community. It is anticipated that smartphone devices will retain data from these storage services. Hence, this research presents a preliminary investigation into the residual artifacts created on an iOS and Android device that has accessed a cloud storage service. The contribution of this paper is twofold. First, it provides an initial assessment on the extent to which cloud storage data is stored on these client-side devices. This view acts as a proxy for data stored in the cloud. Secondly, it provides documentation on the artifacts that could be useful in a digital forensics investigation of cloud services

    A comparison of forensic evidence recovery techniques for a windows mobile smart phone

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    <p>Acquisition, decoding and presentation of information from mobile devices is complex and challenging. Device memory is usually integrated into the device, making isolation prior to recovery difficult. In addition, manufacturers have adopted a variety of file systems and formats complicating decoding and presentation.</p> <p>A variety of tools and methods have been developed (both commercially and in the open source community) to assist mobile forensics investigators. However, it is unclear to what extent these tools can present a complete view of the information held on a mobile device, or the extent the results produced by different tools are consistent.</p> <p>This paper investigates what information held on a Windows Mobile smart phone can be recovered using several different approaches to acquisition and decoding. The paper demonstrates that no one technique recovers all information of potential forensic interest from a Windows Mobile device; and that in some cases the information recovered is conflicting.</p&gt

    SPECTOR3D: A Resistive Magnetohydrodynamic Stability Code for Stellarators

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    SPECTOE3D is a magnetohydrodynamic (MHD) code designed to study the resistive stability and mode spectrum of stellar ators. It finds the spectrum of the linearized, compressible, resistive MHD equations. Some typical results are given for a tokamak mode

    A comparison of incompressible limits for resistive plasmas

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    The constraint of incompressibility is often used to simplify the magnetohydrodynamic (MHD) description of linearized plasma dynamics because it does not affect the ideal MHD marginal stability point. In this paper two methods for introducing incompressibility are compared in a cylindrical plasma model: In the first method, the limit γ\gamma \to \infty is taken, where γ\gamma is the ratio of specific heats; in the second, an anisotropic mass tensor ρ\mathbf{\rho} is used, with the component parallel to the magnetic field taken to vanish, ρ0\rho_{\parallel} \to 0. Use of resistive MHD reveals the nature of these two limits because the Alfv\'en and slow magnetosonic continua of ideal MHD are converted to point spectra and moved into the complex plane. Both limits profoundly change the slow-magnetosonic spectrum, but only the second limit faithfully reproduces the resistive Alfv\'en spectrum and its wavemodes. In ideal MHD, the slow magnetosonic continuum degenerates to the Alfv\'en continuum in the first method, while it is moved to infinity by the second. The degeneracy in the first is broken by finite resistivity. For numerical and semi-analytical study of these models, we choose plasma equilibria which cast light on puzzling aspects of results found in earlier literature.Comment: 14 pages, 10 figure

    Searching of gapped repeats and subrepetitions in a word

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    A gapped repeat is a factor of the form uvuuvu where uu and vv are nonempty words. The period of the gapped repeat is defined as u+v|u|+|v|. The gapped repeat is maximal if it cannot be extended to the left or to the right by at least one letter with preserving its period. The gapped repeat is called α\alpha-gapped if its period is not greater than αv\alpha |v|. A δ\delta-subrepetition is a factor which exponent is less than 2 but is not less than 1+δ1+\delta (the exponent of the factor is the quotient of the length and the minimal period of the factor). The δ\delta-subrepetition is maximal if it cannot be extended to the left or to the right by at least one letter with preserving its minimal period. We reveal a close relation between maximal gapped repeats and maximal subrepetitions. Moreover, we show that in a word of length nn the number of maximal α\alpha-gapped repeats is bounded by O(α2n)O(\alpha^2n) and the number of maximal δ\delta-subrepetitions is bounded by O(n/δ2)O(n/\delta^2). Using the obtained upper bounds, we propose algorithms for finding all maximal α\alpha-gapped repeats and all maximal δ\delta-subrepetitions in a word of length nn. The algorithm for finding all maximal α\alpha-gapped repeats has O(α2n)O(\alpha^2n) time complexity for the case of constant alphabet size and O(nlogn+α2n)O(n\log n + \alpha^2n) time complexity for the general case. For finding all maximal δ\delta-subrepetitions we propose two algorithms. The first algorithm has O(nloglognδ2)O(\frac{n\log\log n}{\delta^2}) time complexity for the case of constant alphabet size and O(nlogn+nloglognδ2)O(n\log n +\frac{n\log\log n}{\delta^2}) time complexity for the general case. The second algorithm has O(nlogn+nδ2log1δ)O(n\log n+\frac{n}{\delta^2}\log \frac{1}{\delta}) expected time complexity

    Estimativa do nível crítico de cobre para a soja, em solos do cerrado brasileiro.

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    A prática da monocultura de soja no Brasil, com o passar do tempo, pode diminuir o teor de matéria orgânica dos solos, sendo esse problema mais sério em solos arenosos. Isso tem aumentado a deficiência de certos micronutrientes, em especial o cobre (Cu). Além disso, a aplicação de adubos, muitas vezes em demasia e sem critério técnico, pode provocar problemas nutricionais de toxicidade ou deficiência desse micronutriente. Com a expansão da soja nas regiões de solos de Cerrado, passou-se para o cultivo em solos de textura média a arenosa, com teores de argila inferiores a 200 g.kg-1, CTC baixa e, originalmente, com baixo teor de Cu. Foram instalados experimentos, com a cultura da soja, em três solos do Cerrado: Latossolo Vermelho Amarelo (LVA) com 260 g.kg-1 de argila, no município de Tasso Fragoso, Latossolo Vermelho (LV) com 450 g.kg-1 de argila, no município de São Raimundo das Mangabeiras, ambos no sul do Estado do Maranhão e em Latossolo Vermelho (LV) com 550 g.kg-1 de argila, no município de Pedra Preta, sudeste do Estado do Mato Grosso, com seis doses de Cu (0; 1,25; 2,5; 5,0; 10 e 20 kg/ha), da fonte sulfato de cobre (30% de Cu) e seis níveis de saturação de bases (V%=30, 40, 50, 60, 70 e 80), com quatro repetições. Os valores estimados, acima dos quais não é esperada resposta à aplicação de cobre, são de 0,74 mg.dm-3 e 0,34 mg.dm-3 de Cu2+, pelos métodos Mehlich e DTPA, respectivamente. Portanto, as faixas de Cu no solo em mg.dm-3, para interpretação dos níveis do nutriente no solo são: para o Método Mehlich-1; Baixo 0,74. Para o Método DTPA; Baixo 0,34

    Recently Integrated Alu Elements In Capuchin Monkeys: A Resource For Cebus/Sapajus Genomics

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    Capuchins are platyrrhines (monkeys found in the Americas) within the Cebidae family. For most of their taxonomic history, the two main morphological types of capuchins, gracile (untufted) and robust (tufted), were assigned to a single genus, Cebus. Further, all tufted capuchins were assigned to a single species, Cebus apella, despite broad geographic ranges spanning Central and northern South America. In 2012, tufted capuchins were assigned to their genus, Sapajus, with eight currently recognized species and five Cebus species, although these numbers are still under debate. Alu retrotransposons are a class of mobile element insertion (MEI) widely used to study primate phylogenetics. However, Alu elements have rarely been used to study capuchins. Recent genome-level assemblies for capuchins (Cebus imitator; [Cebus_imitator_1.0] and Sapajus apella [GSC_monkey_1.0]) facilitated large scale ascertainment of young lineage-specific Alu insertions. Reported here are 1607 capuchin specific and 678 Sapajus specific Alu insertions along with candidate oligonucleotides for locus-specific PCR assays for many elements. PCR analyses identified 104 genus level and 51 species level Alu insertion polymorphisms. The Alu datasets reported in this study provide a valuable resource that will assist in the classification of archival samples lacking phenotypic data and for the study of capuchin phylogenetic relationships

    Linking tree growth rate, damage repair, and susceptibility to a genus-specific pest infestation

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    Pest preference and subsequent susceptibility of a host individual is likely related to previous growth patterns in that host. Emerald ash borer (Agrilus planipennis Fairmaire) is a pestiferous beetle introduced to North America from Asia. While all species of ash are susceptible to attack, some individual trees appear to survive infestation. We selected ash trees in southeastern Michigan, collected cores and categorized trees as high tolerance to emerald ash borer attack (high overall health, low crown dieback), low tolerance (low overall health, high crown dieback) and intermediate tolerance (in-between the other categories). We artificially wounded trees and measured wound closure after 3 years. Ring width indices were not correlated between high and low tolerance trees. Regression slopes comparing growth and years were significantly different between the three tolerance categories, with high tolerance trees having the steepest slope. Wound closure was greatest in high tolerance trees. High tolerance trees demonstrating more rapid (steeper regression slope), consistent (lower variance), and effective (greater wound closure) growth. Those vigorously growing trees likely had more capacity to repair damage caused by emerald ash borer, leading to healthier trees in our categorization. Linking previous host growth patterns to health may have implications related to identifying individual trees potentially tolerant to attack
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