32,372 research outputs found
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Students' everyday problems: a systematic qualitative analysis
The growing acceptance ofqualitative research promises to minimise the perceived gap between counselling practitioner and counselling researcher, but brings with it the challenge offinding methods for dealing systematically, yet respectfully, with textual data. This article presents just such a method. Seventy-five students provided brief descriptions of the everyday problems of their university careers. A random sample of these first hand accounts was then sorted by 30 further students. Hierarchical cluster analysis and multidimensional scaling procedures were used to construct a categorical and dimensional framework within which the original first hand accounts are explored in more detail
MC2: A framework and service for MPEG-7 content-modelling communities
This article is available open access through the publisher’s website through the link below. Copyright @ The Author 2012.Harnessing the power of Web communities, the effort on creating metadata can be greatly reduced. Collaborative communities can create, update and maintain content models for multimedia resources more effectively than single users working alone. This paper presents MC2, a framework for MPEG-7 content-modelling communities. MC2 is based on the challenges to collaborative multimedia content modelling reported in the research literature and the results of an experiment undertaken to investigate user behaviour in collaborative content modelling. An MC2 service has also been implemented as a proof of concept for this framework, which is evaluated with a population of users and against the challenges.EPSR
Finite horizon H[sub ∞] fixed-lag smoothing for time-varying continuous systems
2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Hierarchical Re-estimation of Topic Models for Measuring Topical Diversity
A high degree of topical diversity is often considered to be an important
characteristic of interesting text documents. A recent proposal for measuring
topical diversity identifies three elements for assessing diversity: words,
topics, and documents as collections of words. Topic models play a central role
in this approach. Using standard topic models for measuring diversity of
documents is suboptimal due to generality and impurity. General topics only
include common information from a background corpus and are assigned to most of
the documents in the collection. Impure topics contain words that are not
related to the topic; impurity lowers the interpretability of topic models and
impure topics are likely to get assigned to documents erroneously. We propose a
hierarchical re-estimation approach for topic models to combat generality and
impurity; the proposed approach operates at three levels: words, topics, and
documents. Our re-estimation approach for measuring documents' topical
diversity outperforms the state of the art on PubMed dataset which is commonly
used for diversity experiments.Comment: Proceedings of the 39th European Conference on Information Retrieval
(ECIR2017
The gradient of potential vorticity, quaternions and an orthonormal frame for fluid particles
The gradient of potential vorticity (PV) is an important quantity because of
the way PV (denoted as ) tends to accumulate locally in the oceans and
atmospheres. Recent analysis by the authors has shown that the vector quantity
\bdB = \bnabla q\times \bnabla\theta for the three-dimensional incompressible
rotating Euler equations evolves according to the same stretching equation as
for \bom the vorticity and \bB, the magnetic field in magnetohydrodynamics
(MHD). The \bdB-vector therefore acts like the vorticity \bom in Euler's
equations and the \bB-field in MHD. For example, it allows various analogies,
such as stretching dynamics, helicity, superhelicity and cross helicity. In
addition, using quaternionic analysis, the dynamics of the \bdB-vector
naturally allow the construction of an orthonormal frame attached to fluid
particles\,; this is designated as a quaternion frame. The alignment dynamics
of this frame are particularly relevant to the three-axis rotations that
particles undergo as they traverse regions of a flow when the PV gradient
\bnabla q is large.Comment: Dedicated to Raymond Hide on the occasion of his 80th birthda
Supervised LLE in ICA space for facial expression recognition
Author name used in this publication: David ZhangRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Necessary and sufficient condition for finite horizon H[sub ∞] estimation of time delay systems
Author name used in this publication: David ZhangVersion of RecordPublishe
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Spatial and temporal variablity of nonmethane hydrocarbon mixing ratios and their relation to photochemical lifetime
The relationship between temporal and spatial variability of C2-C8 nonmethane hydrocarbon mixing ratios and their HO lifetimes (τ) is presented for samples collected during the 1993 North Atlantic Regional Experiment (NARE) and from other urban and remote sites. The C2-C4 alkanes, acetylene and benzene typically define a trend of the form slnx=Aτ-b where slnx is the standard deviation of the ln of the mixing ratio. The relationship extended over a wider range of hydrocarbons in winter. The exponent b ranged in value from 0.2±0.023 for winter urban data where C2-C8 hydrocarbons defined a strongly correlated trend, to 0.56±0.15 for C2-C4 hydrocarbons at a coastal site in Nova Scotia during NARE. The trends are significantly different from that given by the Junge relationship [Junge, 1974]. Data from the Azores do not display such a trend and were likely influenced by local emissions. Variance trends are a useful analytical tool for examining the validity of hydrocarbon measurements
Kissing Bonds in Diffusion Bonded Parts
The widespread application of diffusion bonding has been hindered, in part, by concerns over kissing bonds. Kissing bonds are generally considered to be conditions where a bond has little or no strength and the concern is that such conditions might escape detection. At Rohr we differentiate between an intimate contact disbond (which has no bond between the surfaces but is detectable by careful ultrasonic testing) and a kissing bond (which also has no bond between the surfaces but is not detectable using current ultrasonic technology). These definitions will be used throughout
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