104 research outputs found

    Android application forensics: A survey of obfuscation, obfuscation detection and deobfuscation techniques and their impact on investigations

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    Android obfuscation techniques include not only classic code obfuscation techniques that were adapted to Android, but also obfuscation methods that target the Android platform specifically. This work examines the status-quo of Android obfuscation, obfuscation detection and deobfuscation. Specifically, it first summarizes obfuscation approaches that are commonly used by app developers for code optimization, to protect their software against code theft and code tampering but are also frequently misused by malware developers to circumvent anti-malware products. Secondly, the article focuses on obfuscation detection techniques and presents various available tools and current research. Thirdly, deobfuscation (which aims at reinstating the original state before obfuscation) is discussed followed by a brief discussion how this impacts forensic investigation. We conclude that although obfuscation is widely used in Android app development (benign and malicious), available tools and the practices on how to deal with obfuscation are not standardized, and so are inherently lacking from a forensic standpoint

    Clinical Variation in Common Surgical Procedures in Australia: Implications for Health Expenditure

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    Payments for surgical procedures through the Australian Medical Benefits Scheme (MBS) have a large effect on health budgets. We sought to evaluate the magnitude of surgical variation in five common surgical procedures: endometrial ablation; tonsillectomy in children; laparoscopic herniorraphy; cholecystectomy; and, knee arthroscopy. Methods: The MBS funds only a proportion of treatment costs affecting the potential affordability of surgery according to socio-economic factors. We hypothesised that lower rates of unemployment, higher average weekly earnings, a higher proportion of the population with private health insurance, and a higher percentage of the population in higher socio-economic brackets would be associated with a higher uptake of the procedures. Since surgery is more likely to be accessible in capital cities or larger regional centres, we also hypothesised that geographical isolation would be associated with lower access to surgical procedures. The relationship between surgical uptake and socio-economic factors was examined using linear regression and double bootstrap was used for statistical inference in an assumption-lean regression setting. Conclusion: We identified clinical variation in four of the five procedures studied. This variation was not associated with affordability or geographical access factors

    Regional Variation in Rates of IVF Treatment across Australia: A Population-based Study

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    Background: There is variation in uptake of in vitro fertilisation (IVF) between countries, and Australia has high incidence rates of IVF due to universal public funding. However, it remains unclear whether there is regional variation and, if present, what might cause this. Objectives: We sought to determine whether regional variations in treatment rates existed and what might influence these. Methods: The number of cycles of fresh IVF and intrauterine insemination (IUI) for women were obtained for the period 2011 until 2014 in two age groups (25 to 34 years and 35 to 44 years) to calculate incidence rates. Proxy indicators that might influence treatment affordability were: unemployment rates; average weekly total earnings; coverage of private health insurance; and, percentage of women in the highest socioeconomic quintile. Measures of accessibility considered were percentage of the population remote from urban areas and average state population density. Linear regressions were performed using log-transformed ratio of IVF and IUI incidence rates. Results: Variations were found in IVF uptake between states with greater differences in older women. There was no significant association between IVF procedures and population density or geographic isolation. Economic factors were not associated with IVF uptake. Conclusion: These findings suggest that factors such as physician preference, clinical practice guidelines, and cryopreservation protocols of ART units might explain the national variation in uptake of IVF

    Constraints on the neutron star equation of state from AT2017gfo using radiative transfer simulations

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    The detection of the binary neutron star GW170817 together with the observation of electromagnetic counterparts across the entire spectrum inaugurated a new era of multi-messenger astronomy. In this study we incorporate wavelength-dependent opacities and emissivities calculated from atomic-structure data enabling us to model both the measured lightcurves and spectra of the electromagnetic transient AT2017gfo. Best-fits of the observational data are obtained by Gaussian Process Regression, which allows us to present posterior samples for the kilonova and source properties connected to GW170817. Incorporating constraints obtained from the gravitational wave signal obtained by the LIGO-Virgo Scientific Collaboration, we present a 90%90\% upper bound on the mass ratio q1.38q \lesssim 1.38 and a lower bound on the tidal deformability of Λ~197\tilde{\Lambda} \gtrsim 197, which rules out sufficiently soft equations of state. Our analysis is a path-finder for more realistic kilonova models and shows how the combination of gravitational wave and electromagnetic measurements allow for stringent constraints on the source parameters and the supranuclear equation of state

    Greening of grey infrastructure should not be used as a Trojan horse to facilitate coastal development

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    Climate change and coastal urbanization are driving the replacement of natural habitats with artificial structures and reclaimed land globally. These novel habitats are often poor surrogates for natural habitats. The application of integrated greening of grey infrastructure (IGGI) to artificial shorelines demonstrates how multifunctional structures can provide biodiversity benefits whilst simultaneously serving their primary engineering function. IGGI is being embraced globally, despite many knowledge gaps and limitations. It is a management tool to compensate anthropogenic impacts as part of the Mitigation Hierarchy. There is considerable scope for misuse and ‘greenwashing’ however, by making new developments appear more acceptable, thus facilitating the regulatory process. We encourage researchers to exercise caution when reporting on small-scale experimental trials. We advocate that greater attention is paid to when experiments ‘fail’ or yield unintended outcomes. We advise revisiting, repeating and expanding on experiments to test responses over broader spatio-temporal scales to improve the evidence base. Synthesis and applications. Where societal and economic demand makes development inevitable, particular attention should be paid to avoiding, minimizing and rehabilitating environmental impacts. Integrated greening of grey infrastructure (IGGI) should be implemented as partial compensation for environmental damage. Mutual benefits for both humans and nature can be achieved when IGGI is implemented retrospectively in previously developed or degraded environments. We caution, however, that any promise of net biodiversity gain from new developments should be scrutinized and any local ecological benefits set in the context of the wider environmental impacts. A ‘greened’ development will always impinge on natural systems, a reality that is much less recognized in the sea than on land.</p

    Direct experimental measurement of single-mode and mode-hopping dynamics in frequency swept lasers

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    A time-resolved study is presented of the single-mode and mode-switching dynamics observed in swept source vertical cavity surfing emitting lasers and swept wavelength short external cavity lasers. A self-delayed interferometric technique is used to experimentally measure the phase and intensity of these frequency swept lasers, allowing direct examination of the modal dynamics. Visualisation of the instantaneous optical spectrum reveals mode-hop free single mode lasing in the case of the vertical cavity laser, with a tuning rate of 6.3 GHz/ns. More complex mode-switching behaviour occurs in the external cavity laser, with the mode-hopping dynamics found to be dominated by the deterministic movement of the spectral filter. Evidence of transient multi-mode operation and mode-pulling is also presented. (C) 2017 Optical Society of Americ

    Design catalogue for eco-engineering of coastal artificial structures:a multifunctional approach for stakeholders and end-users

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    Coastal urbanisation, energy extraction, food production, shipping and transportation have led to the global proliferation of artificial structures within the coastal and marine environments (sensu “ocean sprawl”), with subsequent loss of natural habitats and biodiversity. To mitigate and compensate impacts of ocean sprawl, the practice of ecoengineering of artificial structures has been developed over the past decade. Eco-engineering aims to create sustainable ecosystems that integrate human society with the natural environment for the benefit of both. The science of eco-engineering has grown markedly, yet synthesis of research into a user-friendly and practitioner-focused format is lacking. Feedback from stakeholders has repeatedly stated that a “photo user guide” or “manual” covering the range of eco-engineering options available for artificial structures would be beneficial. However, a detailed and structured “user guide” for eco-engineering in coastal and marine environments is not yet possible; therefore we present an accessible review and catalogue of trialled eco-engineering options and a summary of guidance for a range of different structures tailored for stakeholders and end-users as the first step towards a structured manual. This work can thus serve as a potential template for future eco-engineering guides. Here we provide suggestions for potential eco-engineering designs to enhance biodiversity and ecosystem functioning and services of coastal artificial structures with the following structures covered: (1) rock revetment, breakwaters and groynes composed of armour stones or concrete units; (2) vertical and sloping seawalls; (3) over-water structures (i.e., piers) and associated support structures; and (4) tidal river walls

    Search for gravitational wave bursts in LIGO's third science run

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    We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

    Searching for a Stochastic Background of Gravitational Waves with LIGO

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    The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is ΩGW<6.5×105\Omega_{\rm GW} < 6.5 \times 10^{-5}. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure
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