5,268 research outputs found
A Practical Attack on the MIFARE Classic
The MIFARE Classic is the most widely used contactless smart card in the
market. Its design and implementation details are kept secret by its
manufacturer. This paper studies the architecture of the card and the
communication protocol between card and reader. Then it gives a practical,
low-cost, attack that recovers secret information from the memory of the card.
Due to a weakness in the pseudo-random generator, we are able to recover the
keystream generated by the CRYPTO1 stream cipher. We exploit the malleability
of the stream cipher to read all memory blocks of the first sector of the card.
Moreover, we are able to read any sector of the memory of the card, provided
that we know one memory block within this sector. Finally, and perhaps more
damaging, the same holds for modifying memory blocks
Access regulation and the transition from copper to fiber networks in telecoms
In this paper we study the impact of different forms of access obligations on firms' incentives to migrate from the legacy copper network to ultra-fast broadband infrastructures. We analyze three different kinds of regulatory interventions: geographical regulation of access to copper networks-where access prices are differentiated depending on whether or not an alternative fiber network has been deployed; access obligations on fiber networks and its interplay with wholesale copper prices; and, finally, a mandatory switch-off of the legacy copper network-to foster the transition to the higher quality fiber networks. Trading-off the different static and dynamic goals, the paper provides guidelines and suggestions for policy makers' decision
Formation of spatially periodic fronts of high-energy electrons in a radio-frequency driven surface microdischarge
The generation of spatially periodic fronts of high-energy electrons (>13.48 eV) has been investigated in a radio-frequency surface microdischarge in atmospheric-pressure argon. Optical emission spectroscopy is used to study the Ar I 2p1−1s2 transition surrounding a filamentary microdischarge, both spatially and with respect to the phase of the applied voltage. The formation of excitation fronts, which remain at a constant propagation distance throughout the RF cycle and for the duration of the pulse, may be explained by a localized increase in the electric field at the tip of surface-charge layers that are deposited during the extension phase
Energetic electron avalanches and mode transitions in planar inductively coupled radio-frequency driven plasmas operated in oxygen
Peroxiredoxin 4, a novel circulating biomarker for oxidative stress and the risk of incident cardiovascular disease and all-cause mortality
BACKGROUND: Oxidative stress has been suggested to play a key role in the development of cardiovascular disease (CVD). The aim of our study was to investigate the associations of serum peroxiredoxin 4 (Prx4), a hydrogen peroxide-degrading peroxidase, with incident CVD and all-cause mortality. We subsequently examined the incremental value of Prx4 for the risk prediction of CVD compared with the Framingham risk score (FRS). METHODS AND RESULTS: We performed Cox regression analyses in 8141 participants without history of CVD (aged 28 to 75 years; women 52.6%) from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study in Groningen, The Netherlands. Serum Prx4 was measured by an immunoluminometric assay in baseline samples. Main outcomes were: (1) incident CVD events or CVD mortality and (2) all-cause mortality during a median follow-up of 10.5 years. In total, 708 participants (7.8%) developed CVD events or CVD mortality, and 517 participants (6.3%) died. Baseline serum Prx4 levels were significantly higher in participants with incident CVD events or CVD mortality and in those who died than in participants who remained free of outcomes (both P<0.001). In multivariable models with adjustment for Framingham risk factors, hazard ratios were 1.16 (95% CI 1.06 to 1.27, P<0.001) for incident CVD events or CVD mortality and 1.17 (95% CI 1.06 to 1.29, P=0.003) for all-cause mortality per doubling of Prx4 levels. After the addition of Prx4 to the FRS, the net reclassification improvement was 2.7% (P=0.01) using 10-year risk categories of CVD. CONCLUSIONS: Elevated serum Prx4 levels are associated with a significantly higher risk of incident CVD events or CVD mortality and all-cause mortality after adjustment for clinical risk factors. The addition of Prx4 to the FRS marginally improved risk prediction of future CVD
Cold atmospheric pressure plasma jets as sources of singlet delta oxygen for biomedical applications
Nanosecond optical imaging spectroscopy of an electrothermal radiofrequency plasma thruster plume
Nanosecond optical imaging spectroscopy is employed to investigate the spatio-temporal dynamics of the plasma plume expanding from a 4.2 mm-diameter, 20 mm-long cylindrical capacitively coupled electrothermal radiofrequency (rf) driven thruster using 10 W of power at 12.50 MHz and an argon pressure of 1.5 Torr. On-axis, the plume exhibits four distinct peaks of optical emission intensity within the rf period. The plume has a spherical shape with a transient radial extension (during half of the rf cycle) at the thruster exit plane due to an rf current to ground when the grounded electrode acts as an anode
‘I’d be proud to spend the sacred foreign aid budget on our poor pensioners’: Representations of macro aid resourcing in the Irish, UK and US print-media during the economic crisis, 2008–2011
The news-media has been identified as an influence on donor nations’ overseas aid allocations, acting as a site where decisions are justified to ‘domestic constituencies’ and through which resistance is mobilised. Mediated pressures on aid allocations amplified between 2008 and 2011 in three donor countries experiencing domestic economic difficulties: Ireland, the UK and the US. This study suggests that each country’s print-media positioned the macro resourcing of aid primarily as an inward concern, neglected recipient country needs, and made weak connections to international policy frameworks to benchmark, contextualise and rationalise aid allocations. The research suggests that the explanatory limitations of the countries’ news-models in communicating the processes and rationales underpinning macro aid resourcing may be a factor in sustaining a knowledge and legitimacy deficit among domestic publics for international aid agreements
Citizen participation in news
The process of producing news has changed significantly due to the advent of the Web, which has enabled the increasing involvement of citizens in news production. This trend has been given many names, including participatory journalism, produsage, and crowd-sourced journalism, but these terms are ambiguous and have been applied inconsistently, making comparison of news systems difficult. In particular, it is problematic to distinguish the levels of citizen involvement, and therefore the extent to which news production has genuinely been opened up. In this paper we perform an analysis of 32 online news systems, comparing them in terms of how much power they give to citizens at each stage of the news production process. Our analysis reveals a diverse landscape of news systems and shows that they defy simplistic categorisation, but it also provides the means to compare different approaches in a systematic and meaningful way. We combine this with four case studies of individual stories to explore the ways that news stories can move and evolve across this landscape. Our conclusions are that online news systems are complex and interdependent, and that most do not involve citizens to the extent that the terms used to describe them imply
Up and Out: Journalism, Social Media, and Historical Sensibility
Much of the modern theorizing about journalism and communication attained its robustness due to a powerful convergence of distinct middle-range scholarly findings that emerged primarily in the 1970s and 1980s. In the present day, when we turn our analytical gaze to the relationship between journalism and social media, we thus need to strike a delicate balance between conducting new qualitative research, re-conceptualizing and re-interrogating the classic conclusions of political communication scholarship, and linking these two aspects of research together. However, we might also wish to extend our analytical gaze “out,” interrogating the movement of journalistic technology across history, as well as “up,” looking at how journalism fits within larger structural explanations regarding the shape of political life
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