461 research outputs found

    A framework for P2P application development

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    Although Peer-to-Peer (P2P) computing has become increasingly popular over recent years, there still exist only a very small number of application domains that have exploited it on a large scale. This can be attributed to a number of reasons including the rapid evolution of P2P technologies, coupled with their often-complex nature. This paper describes an implemented abstraction framework that seeks to aid developers in building P2P applications. A selection of example P2P applications that have been developed using this framework are also presented

    Arabic dialect identification in the context of bivalency and code-switching

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    In this paper we use a novel approach towards Arabic dialect identification using language bivalency and written code-switching. Bivalency between languages or dialects is where a word or element is treated by language users as having a fundamentally similar semantic content in more than one language or dialect. Arabic dialect identification in writing is a difficult task even for humans due to the fact that words are used interchangeably between dialects. The task of automatically identifying dialect is harder and classifiers trained using only n-grams will perform poorly when tested on unseen data. Such approaches require significant amounts of annotated training data which is costly and time consuming to produce. Currently available Arabic dialect datasets do not exceed a few hundred thousand sentences, thus we need to extract features other than word and character n-grams. In our work we present experimental results from automatically identifying dialects from the four main Arabic dialect regions (Egypt, North Africa, Gulf and Levant) in addition to Standard Arabic. We extend previous work by incorporating additional grammatical and stylistic features and define a subtractive bivalency profiling approach to address issues of bivalent words across the examined Arabic dialects. The results show that our new methods classification accuracy can reach more than 76% and score well (66%) when tested on completely unseen data

    Isis: protecting children in online social networks

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    The aim of the Isis project is to develop an ethics-centred monitoring framework and tools for supporting law enforcement agencies in policing online social networks for the purpose of protecting children. The project is developing natural language analysis techniques to help identify child sex offenders from chat logs and monitoring mechanisms that can be noninvasively attached to file sharing systems for identifying the distributors of child abuse media. The ethical issues associated with such monitoring activities are studied through consultations with representatives from stakeholder communities and fed back into the development of the framework and tools. The project results are to be used and evaluated by specialist international law enforcement agencies as part of their own policing activities

    The interaction of class and gender in illness narratives

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 BSA Publications Ltd.Perspectives on gender and identity that emphasize variability of performance, local context and individual agency have displaced earlier paradigms.These are now perceived to have supported gender stereotypes and language ideologies by emphasizing gender difference and homogeneity within genders. In a secondary analysis of health and illness narratives we explore the interaction of class and gender in individuals' constructions of gendered identity. High social class men perform gender in particularly varied ways and we speculate that this variable repertoire, including the use of what was once termed `women's language', is linked to a capacity to maintain social distinction and authority. Men's performance of conventional masculinity is often threatened by both the experience of illness and being interviewed about personal experience. Lower social class women in particular demonstrate an intensification of a pre-existing informal family and support group culture, marking successful members by awarding them the accolade of being `lovely'.ESR

    Building blocks of joint attention: early sensitivity to having one’s own gaze followed

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    Detecting when one’s own gaze has been followed is a critical component of joint attention, but little is known about its development. To address this issue, we used electroencephalography (EEG) to record infant neural responses at 6.5 and 9.5 months during observation of an adult either turning to look at the same object as the infant (congruent actor), or turning to look at a different object (incongruent actor). We also used a preferential looking paradigm to investigate whether infants would demonstrate a preference for the congruent versus incongruent actor. Greater suppression of alpha band activity in the congruent compared to incongruent condition was revealed at both ages in central and parietal regions. However, the effect of congruency on alpha suppression was stronger at 9.5 months, and only at this age did infants demonstrate a preference towards looking at the congruent actor. Together, these results suggest that although infants are sensitive to others’ gaze following from early on, important neural and behavioural developments occur between 6.5 and 9.5 months

    Early social adversity modulates the relation between attention biases and socioemotional behaviour in juvenile macaques

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    Affect-biased attention may play a fundamental role in early socioemotional development, but factors influencing its emergence and associations with typical versus pathological outcomes remain unclear. Here, we adopted a nonhuman primate model of early social adversity (ESA) to: (1) establish whether juvenile, pre-adolescent macaques demonstrate attention biases to both threatening and reward-related dynamic facial gestures; (2) examine the effects of early social experience on such biases; and (3) investigate how this relation may be linked to socioemotional behaviour. Two groups of juvenile macaques (ESA exposed and non-ESA exposed) were presented with pairs of dynamic facial gestures comprising two conditions: neutral-threat and neutral-lipsmacking. Attention biases to threat and lipsmacking were calculated as the proportion of gaze to the affective versus neutral gesture. Measures of anxiety and social engagement were also acquired from videos of the subjects in their everyday social environment. Results revealed that while both groups demonstrated an attention bias towards threatening facial gestures, a greater bias linked to anxiety was demonstrated by the ESA group only. Only the non-ESA group demonstrated a significant attention bias towards lipsmacking, and the degree of this positive bias was related to duration and frequency of social engagement in this group. These findings offer important insights into the effects of early social experience on affect-biased attention and related socioemotional behaviour in nonhuman primates, and demonstrate the utility of this model for future investigations into the neural and learning mechanisms underlying this relationship across development

    Daubechies wavelets as a basis set for density functional pseudopotential calculations

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    Daubechies wavelets are a powerful systematic basis set for electronic structure calculations because they are orthogonal and localized both in real and Fourier space. We describe in detail how this basis set can be used to obtain a highly efficient and accurate method for density functional electronic structure calculations. An implementation of this method is available in the ABINIT free software package. This code shows high systematic convergence properties, very good performances and an excellent efficiency for parallel calculations.Comment: 15 pages, 11 figure
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