3,681 research outputs found
What Stories Do Young People Tell About Their Past Experience of Social Withdrawal?
This study took as its subject the stories that young people, aged 16 and over, tell about their experience of social withdrawal. It is argued that social withdrawal highlights some of the tensions between paternalistic and enabling modes of supporting young people, particularly in the ‘intermediate period’ of late adolescence and early adulthood. Social interaction is increasingly seen as a necessary element in the development of a full range of capacities in adulthood. At the same time, a critique of this tendency can be identified which appeals to diversity and autonomy, including in relation to social motivation. A review of the literature revealed a sophisticated model of the development of social withdrawal and its associated difficulties, as well as subtypes with distinctive pathways. However, there was a dearth of qualitative analysis of young people’s subjective experience of social withdrawal.
A narrative methodology was adopted to answer research questions centred on stories told and explanations offered about the experience of withdrawal. This was informed by an Object-Oriented Ontology (OOO) and related epistemology. Interviews with four participants were followed up with the co-construction of timelines. Their narratives revealed the importance of specific incidents over longer term tendencies. They also revealed the interaction of power and resistance with feelings of shame and humiliation. Finally, they discussed the changing nature of their selves, discussed in the study in terms of ‘symbiosis’. It is suggested that further research locating withdrawn young people in their social context would be beneficial
Natural statistics for spectral samples
Spectral sampling is associated with the group of unitary transformations
acting on matrices in much the same way that simple random sampling is
associated with the symmetric group acting on vectors. This parallel extends to
symmetric functions, k-statistics and polykays. We construct spectral
k-statistics as unbiased estimators of cumulants of trace powers of a suitable
random matrix. Moreover we define normalized spectral polykays in such a way
that when the sampling is from an infinite population they return products of
free cumulants.Comment: Published in at http://dx.doi.org/10.1214/13-AOS1107 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Niches, rather than neutrality, structure a grassland pioneer guild
Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails
Flexible context aware interface for ambient assisted living
A Multi Agent System that provides a (cared for) person, the subject, with assistance and support through an Ambient Assisted Living Flexible Interface (AALFI) during the day while complementing the night time assistance offered by NOCTURNAL with feedback assistance, is presented. It has been tailored to the subject’s requirements profile and takes into account factors associated with the time of day; hence it attempts to overcome shortcomings of current Ambient Assisted Living Systems. The subject is provided with feedback that highlights important criteria such as quality of sleep during the night and possible breeches of safety during the day. This may help the subject carry out corrective measures and/or seek further assistance. AALFI provides tailored interaction that is either visual or auditory so that the subject is able to understand the interactions and this process is driven by a Multi-Agent System. User feedback gathered from a relevant user group through a workshop validated the ideas underpinning the research, the Multi-agent system and the adaptable interface
Longitudinal LASSO: Jointly Learning Features and Temporal Contingency for Outcome Prediction
Longitudinal analysis is important in many disciplines, such as the study of
behavioral transitions in social science. Only very recently, feature selection
has drawn adequate attention in the context of longitudinal modeling. Standard
techniques, such as generalized estimating equations, have been modified to
select features by imposing sparsity-inducing regularizers. However, they do
not explicitly model how a dependent variable relies on features measured at
proximal time points. Recent graphical Granger modeling can select features in
lagged time points but ignores the temporal correlations within an individual's
repeated measurements. We propose an approach to automatically and
simultaneously determine both the relevant features and the relevant temporal
points that impact the current outcome of the dependent variable. Meanwhile,
the proposed model takes into account the non-{\em i.i.d} nature of the data by
estimating the within-individual correlations. This approach decomposes model
parameters into a summation of two components and imposes separate block-wise
LASSO penalties to each component when building a linear model in terms of the
past measurements of features. One component is used to select features
whereas the other is used to select temporal contingent points. An accelerated
gradient descent algorithm is developed to efficiently solve the related
optimization problem with detailed convergence analysis and asymptotic
analysis. Computational results on both synthetic and real world problems
demonstrate the superior performance of the proposed approach over existing
techniques.Comment: Proceedings of the 21th ACM SIGKDD International Conference on
Knowledge Discovery and Data Mining. ACM, 201
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