Active authentication for mobile devices utilising behaviour profiling.

With nearly 6 billion subscribers around the world, mobile devices have become an indispensable component in modern society. The majority of these devices rely upon passwords and personal identification numbers as a form of user authentication, and the weakness of these point-of-entry techniques is widely documented. Active authentication is designed to overcome this problem by utilising biometric techniques to continuously assess user identity. This paper describes a feasibility study into a behaviour profiling technique that utilises historical application usage to verify mobile users in a continuous manner. By utilising a combination of a rule-based classifier, a dynamic profiling technique and a smoothing function, the best experimental result for a users overall application usage was an equal error rate of 9.8 %. Based upon this result, the paper proceeds to propose a novel behaviour profiling framework that enables a user’s identity to be verified through their application usage in a continuous and transparent manner. In order to balance the trade-off between security and usability, the framework is designed in a modular way that will not reject user access based upon a single application activity but a number of consecutive abnormal application usages. The proposed framework is then evaluated through simulation with results of 11.45 and 4.17 % for the false rejection rate and false acceptance rate, respectively. In comparison with point-of-entry-based approaches, behaviour profiling provides a significant improvement in both the security afforded to the device and user convenience

Temporal trends in radiometrically dated sediment cores from English lakes show polybrominated diphenyl ethers correlate with brominated but not mixed bromo/chloro dioxins and furans

This paper reports concentrations between ~1950 and present, of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), in radiometrically-dated sediment cores from three English lakes. Mixed bromo/chloro dibenzo-p-dioxins and furans (PXDD/Fs) were measured in two of the same lakes. Concentrations of PXDD/Fs decreased over time to the present. To our knowledge, this is the first report of temporal trends of PXDD/Fs in the environment. In contrast, concentrations of PBDEs increased towards the present and were significantly correlated (R = 0.88–0.98; p < 0.05) with concentrations of PBDFs in all three lakes. These observations suggest that the sources of PXDD/Fs are not related to PBDEs and differ from those of PBDFs. We also report for the first time the presence of octabromodibenzofuran (OBDF) in the two most recent core slices at one lake. The source of OBDF in these samples is unclear. While OBDF has been reported previously as a significant contaminant of some commercial formulations of Deca-BDE, it is also present in Octa-BDE products and in emissions from a variety of combustion activities. Overall, while the positive correlation between PBDEs and PBDFs suggests increased use of PBDEs has contributed substantially to environmental contamination with PBDFs; examination of PBDF homologue patterns implies emissions from combustion activities are likely also important

REDD+ on the rocks? Conflict over forest and politics of justice in Vietnam

In Vietnam, villagers involved in a REDD+ (reduced emissions from deforestation and forest degradation) pilot protect areas with rocks which have barely a tree on them. The apparent paradox indicates how actual practices differ from general ideas about REDD+ due to ongoing conflict over forest, and how contestations over the meaning of justice are a core element in negotiations over REDD+. We explore these politics of justice by examining how the actors involved in the REDD+ pilot negotiate the particular subjects, dimensions, and authority of justice considered relevant, and show how politics of justice are implicit to practical decisions in project implementation. Contestations over the meaning of justice are an important element in the practices and processes constituting REDD+ at global, national and local levels, challenging uniform definitions of forest justice and how forests ought to be managed

Serious Games Application for Memory Training Using Egocentric Images

Mild cognitive impairment is the early stage of several neurodegenerative diseases, such as Alzheimer's. In this work, we address the use of lifelogging as a tool to obtain pictures from a patient's daily life from an egocentric point of view. We propose to use them in combination with serious games as a way to provide a non-pharmacological treatment to improve their quality of life. To do so, we introduce a novel computer vision technique that classifies rich and non rich egocentric images and uses them in serious games. We present results over a dataset composed by 10,997 images, recorded by 7 different users, achieving 79% of F1-score. Our model presents the first method used for automatic egocentric images selection applicable to serious games.Comment: 11 page

Intergrain Effects in the AC Susceptibility of Polycrystalline LaFeAsO_{0.94}F_{0.06}

The AC susceptibility, chi, at zero DC magnetic field of a polycrystalline sample of LaFeAsO_{0.94}F_{0.06} (Tc ≈ 24 K) has been investigated as a function of the temperature, the amplitude of the AC magnetic field (in the range Hac = 0.003 Oe - 4 Oe) and the frequency (in the range f = 10 kHz - 100 kHz). The chi(T) curve exhibits the typical two-step transition arising from the combined response of superconducting grains and intergranular weak-coupled medium. The intergranular part of chi strongly depends on both the amplitude and the frequency of the AC driving field, from few Kelvin below Tc down to T = 4.2 K. Our results show that, in the investigated sample, the intergrain critical current is not determined by pinning of Josephson vortices but by Josephson critical current across neighboring grains

Multiphoton Interference in Quantum Fourier Transform Circuits and Applications to Quantum Metrology

© 2017 American Physical Society. Quantum Fourier transforms (QFTs) have gained increased attention with the rise of quantum walks, boson sampling, and quantum metrology. Here, we present and demonstrate a general technique that simplifies the construction of QFT interferometers using both path and polarization modes. On that basis, we first observe the generalized Hong-Ou-Mandel effect with up to four photons. Furthermore, we directly exploit number-path entanglement generated in these QFT interferometers and demonstrate optical phase supersensitivities deterministically

On the margins with heroin use: generational perspectives

Session: WED10 - Patterns of crime and delinquency - Theme: Contemporary CriminologyHong Kong has a long history with heroin consumption, with its emergence directly tied to the international pressures on the British to criminalize its’ colonial benefits with opium. For much of the latter half of the 20th century, heroin dominated Hong Kong’s local drug market, and heroin users, typically lower working class males, though publicly tolerated, came to be highly stigmatized and marginalized in the community. By the end of the century, recreational use of psychotropic drugs emerged, following similar patterns globally with ecstasy and the dance party setting attracting young people from a variety of social classes. Yet within a year, ketamine took center stage, becoming the most popular drug among young persons and used in settings beyond the dance scene. At the same time, heroin use among young persons declined significantly. The aim of this paper is to examine the experiences of initiating into heroin use and experiences of marginality of three generations of heroin users, including a group of young, middle aged, and elderly users. The study draws from 65 indepth interviews with users of different ages to address the question as to how are their experiences differ and their position in this era of change and transition in the local drug market and in the community?postprin

Implications of Shallower Memory Controller Transaction Queues in Scalable Memory Systems

Scalable memory systems provide scalable bandwidth to the core growth demands in multicores and embedded systems processors. In these systems, as memory controllers (MCs) are scaled, memory traffic per MC is reduced, so transaction queues become shallower. As a consequence, there is an opportunity to explore transaction queue utilization and its impact on energy utilization. In this paper, we propose to evaluate the performance and energy-per-bit impact when reducing transaction queue sizes along with the MCs of these systems. Experimental results show that reducing 50 % on the number of entries, bandwidth and energy-per-bit levels are not affected, whilst reducing aggressively of about 90 %, bandwidth is similarly reduced while causing significantly higher energy-per-bit utilization