257 research outputs found

    Identifying bugs in digital forensic tools

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    Bugs can be found in all code and the consequences are usually managed through up-grade releases, patches, and restarting operating systems and applications. However, in mission critical systems complete fall over systems are built to assure service continuity. In our research we asked the question, what are the professional risks of bugs in digital forensic tools? Our investigation reviewed three high use professional proprietary digital forensic tools, one in which we identified six bugs and evaluated these bug in terms of potential impacts on an investigator\u27s work. The findings show that yes major brand name digital forensic tools have software bugs and there is room for improvement. These bugs had potential to frustrate an investigator, to cost time, to lose evidence and to require compensatory strategies. Such software bugs also have the potential for malicious exploitation and anti-forensic use

    Crystal field analysis of Dy and Tm implanted silicon for photonic and quantum technologies

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    We report the lattice site and symmetry of optically active Dy3+ and Tm3+ implanted Si. Local symmetry was determined by fitting crystal field parameters (CFPs), corresponding to various common symmetries, to the ground state splitting determined by photoluminescence measurements. These CFP values were then used to calculate the splitting of every J manifold. We find that both Dy and Tm ions are in a Si substitution site with local tetragonal symmetry. Knowledge of rare-earth ion symmetry is important in maximising the number of optically active centres and for quantum technology applications where local symmetry can be used to control decoherence

    The activation energy for GaAs/AlGaAs interdiffusion

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    Copyright 1997 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Journal of Applied Physics 82, 4842 (1997) and may be found at

    Electrical properties of Bi-implanted amorphous chalcogenide films

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    The impact of Bi implantation on the conductivity and the thermopower of amorphous chalcogenide films is investigated. Incorporation of Bi in Ge-Sb-Te and GeTe results in enhanced conductivity. The negative Seebeck coefficient confirms onset of the electron conductivity in GeTe implanted with Bi at a dose of 2x1016 cm-2. The enhanced conductivity is accompanied by defect accumulation in the films upon implantation as is inferred by using analysis of the space-charge limited current. The results indicate that native coordination defects in lone-pair semiconductors can be deactivated by means of ion implantation, and higher conductivity of the films stems from additional electrically active defects created by implantation of bismuth.Comment: This is an extended version of the results presented in Proc. SPIE 8982, 898213 (2014

    Rural protein insufficiency in a wildlife-depleted west African farm-forest landscape

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    Introduction: Wildlife is an important source of protein for many people in developing countries. Yet wildlife depletion due to overexploitation is common throughout the humid tropics and its effect on protein security, especially for vulnerable households, is poorly understood. This is problematic for both sustainable rural development and conservation management. Methods: This study investigates a key dimension of protein security in a cash-crop farming community living in a wildlife-depleted farm-forest landscape in SW Ghana, a region where protein–energy malnutrition persists. Specifically, we monitored protein sufficiency, defined as whether consumption met daily requirements, as benchmarked by recommended daily allowance (RDA). We focus on whether more vulnerable households were less likely to be able to meet their protein needs, where vulnerability was defined by wealth, agricultural season and gender of the household head. Our central hypothesis was: (a) vulnerable households are less likely to consume sufficient protein. In the context that most plant proteins were home-produced, so likely relatively accessible to all households, while most animal proteins were purchased, so likely less accessible to vulnerable households, we tested two further hypotheses: (b) vulnerable households depend more on plant protein to cover their protein needs; and (c) vulnerable households are less likely to earn sufficient cash income to meet their protein needs through purchased animal sources. Results: Between 14% and 60% of households (depending on plant protein content assumptions) consumed less than the RDA for protein, but neither protein consumption nor protein sufficiency co-varied with household vulnerability. Fish, livestock and food crops comprised 85% of total protein intake and strongly affected protein sufficiency. However, bushmeat remained an important protein source (15% of total consumption), especially during the post-harvest season when it averaged 26% of total protein consumption. Across the year, 89% of households experienced at least one occasion when they had insufficient income to cover their protein needs through animal protein purchases. The extent of this income shortage was highest during the lean season and among poorer households. Conclusions: These findings indicate that despite wildlife depletion, bushmeat continues to make a substantial contribution to protein consumption, especially during the agricultural lean season. Income shortages among farmers limit their ability to purchase bushmeat or its substitutes, suggesting that wildlife depletion may cause malnutrition

    The PULSE@Parkes project: A new observing technique for long-term pulsar monitoring

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    The PULSE@Parkes project has been designed to monitor the rotation of radio pulsars over time spans of days to years. The observations are obtained using the Parkes 64-m and 12-m radio telescopes by Australian and international high school students. These students learn the basis of radio astronomy and undertake small projects with their observations. The data are fully calibrated and obtained with the state-of-the-art pulsar hardware available at Parkes. The final data sets are archived and are currently being used to carry out studies of 1) pulsar glitches, 2) timing noise, 3) pulse profile stability over long time scales and 4) the extreme nulling phenomenon. The data are also included in other projects such as gamma-ray observatory support and for the Parkes Pulsar Timing Array project. In this paper we describe the current status of the project and present the first scientific results from the Parkes 12-m radio telescope. We emphasise that this project offers a straightforward means to enthuse high school students and the general public about radio astronomy while obtaining scientifically valuable data sets.Comment: accepted for publication by PAS

    n-type chalcogenides by ion implantation.

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    Carrier-type reversal to enable the formation of semiconductor p-n junctions is a prerequisite for many electronic applications. Chalcogenide glasses are p-type semiconductors and their applications have been limited by the extraordinary difficulty in obtaining n-type conductivity. The ability to form chalcogenide glass p-n junctions could improve the performance of phase-change memory and thermoelectric devices and allow the direct electronic control of nonlinear optical devices. Previously, carrier-type reversal has been restricted to the GeCh (Ch=S, Se, Te) family of glasses, with very high Bi or Pb 'doping' concentrations (~5-11 at.%), incorporated during high-temperature glass melting. Here we report the first n-type doping of chalcogenide glasses by ion implantation of Bi into GeTe and GaLaSO amorphous films, demonstrating rectification and photocurrent in a Bi-implanted GaLaSO device. The electrical doping effect of Bi is observed at a 100 times lower concentration than for Bi melt-doped GeCh glasses.This work was supported by the UK EPSRC grants EP/I018417/1, EP/I019065/1 and EP/I018050/1.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ncomms634

    MontanAqua : Wasserbewirtschaftung in Zeiten von Knappheit und globalem Wandel. Wasserbewirtschaftungsoptionen für die Region Crans-Montana-Sierre im Wallis

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    Das nationale Forschungsprogramm NFP 61 «Nachhaltige Wassernutzung » des Schweizerischen Nationalfonds hat sich zum Ziel gesetzt, wissenschaftliche Grundlagen zur nachhaltigen Wasserbewirtschaftung in der Schweiz zu liefern. Als Teil dieses Forschungsvorhabens wurde im Rahmen des Projektes MontanAqua die Wasserbewirtschaftung der Region Crans-Montana-Sierre (Wallis) untersucht. Es ging dabei darum, in enger Zusammenarbeit mit den in der Region betroffenen Akteuren nachhaltige Wassernutzungsstrategien für die Zukunft zu entwickeln. MontanAqua hat sich vertieft mit den bestehenden Systemen der Wasserbewirtschaftung auf der regionalen Skala (11 Gemeinden) auseinandergesetzt. Dazu wurden die zukünftigen Auswirkungen der klimatischen und sozioökonomischen Veränderungen einbezogen. Das Forschungsteam analysierte die aktuelle Situation anhand von quantitativen, qualitativen sowie kartografischen Methoden und kombinierte diese mit Modellberechnungen. Für die Modellierung der Zukunft wurden regionale Klimaszenarien und vier mit lokalen Akteuren entwickelte sozioökonomische Szenarien verwendet. Dieser Überblick fasst die Resultate des Projektes MontanAqua zusammen. Fünf wesentliche Fragen werden beantwortet und fünf Kernbotschaften erläutert. Zudem sind Empfehlungen für die Verantwortlichen der regionalen und kantonalen Wasserbewirtschaftung formuliert
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