351 research outputs found
Be Your Own Curator with the CHIP Tour Wizard [html]
Web 2.0 enables increased access to the museum digital
collection. More and more, users will spend time preparing
their visits to the museums and reflecting on them after the
visits. In this context, the CHIP (Cultural Heritage
Information Personalization) project offers tools to the
users to be their own curator, e.g. planning a personalized
museum tour, discovering interesting artworks they want to
see in a 'virtual' or a 'real' tour and quickly finding their
ways in the museum. In this paper we present the new
additions to the CHIP tools, which target the above
functionality - a Web-based Tour Preparation Wizard and
an export of a personalized tour to an interactive Mobile
Guide used in the physical museum space. In addition, the
user interactions during a real museum visit are stored and
synchronized with the user model, which is maintained at
the museum Web site
Be Your Own Curator with the CHIP Tour Wizard [pdf]
Web 2.0 enables increased access to the museum digital
collection. More and more, users will spend time preparing
their visits to the museums and reflecting on them after the
visits. In this context, the CHIP (Cultural Heritage
Information Personalization) project offers tools to the
users to be their own curator, e.g. planning a personalized
museum tour, discovering interesting artworks they want to
see in a 'virtual' or a 'real' tour and quickly finding their
ways in the museum. In this paper we present the new
additions to the CHIP tools, which target the above
functionality - a Web-based Tour Preparation Wizard and
an export of a personalized tour to an interactive Mobile
Guide used in the physical museum space. In addition, the
user interactions during a real museum visit are stored and
synchronized with the user model, which is maintained at
the museum Web site
Multi-label classification with output kernels
Although multi-label classification has become an increasingly important problem in machine learning, current approaches remain restricted to learning in the original label space (or in a simple linear projection of the original label space). Instead, we propose to use kernels on output label vectors to significantly expand the forms of label dependence that can be captured. The main challenge is to reformulate standard multi-label losses to handle kernels between output vectors. We first demonstrate how a state-of-the-art large margin loss for multi-label classification can be reformulated, exactly, to handle output kernels as well as input kernels. Importantly, the pre-image problem for multi-label classification can be easily solved at test time, while the training procedure can still be simply expressed as a quadratic program in a dual parameter space. We then develop a projected gradient descent training procedure for this new formulation. Our empirical results demonstrate the efficacy of the proposed approach on complex image labeling tasks
Influence of Spatial Correlations on the Lasing Threshold of Random Lasers
The lasing threshold of a random laser is computed numerically from a generic
model. It is shown that spatial correlations of the disorder in the medium
(i.e., dielectric constant) lead to an increase of the decay rates of the
eigenmodes and of the lasing threshold. This is in conflict with predictions
that such correlations should lower the threshold. While all results are
derived for photonic systems, the computed decay rate distributions also apply
to electronic systems
Multipole interaction between atoms and their photonic environment
Macroscopic field quantization is presented for a nondispersive photonic
dielectric environment, both in the absence and presence of guest atoms.
Starting with a minimal-coupling Lagrangian, a careful look at functional
derivatives shows how to obtain Maxwell's equations before and after choosing a
suitable gauge. A Hamiltonian is derived with a multipolar interaction between
the guest atoms and the electromagnetic field. Canonical variables and fields
are determined and in particular the field canonically conjugate to the vector
potential is identified by functional differentiation as minus the full
displacement field. An important result is that inside the dielectric a dipole
couples to a field that is neither the (transverse) electric nor the
macroscopic displacement field. The dielectric function is different from the
bulk dielectric function at the position of the dipole, so that local-field
effects must be taken into account.Comment: 17 pages, to be published in Physical Review
Analyzing sensory data using non-linear preference learning with feature subset selection
15th European Conference on Machine Learning, Pisa, Italy, September 20-24, 2004The quality of food can be assessed from different points of view. In this paper, we deal with those aspects that can be appreciated through sensory impressions. When we are aiming to induce a function that maps object descriptions into ratings, we must consider that consumers’ ratings are just a way to express their preferences about the products presented in the same testing session. Therefore, we postulate to learn from consumers’ preference judgments instead of using an approach based on regression. This requires the use of special purpose kernels and feature subset selection methods. We illustrate the benefits of our approach in two families of real-world data base
Photon Localization in Resonant Media
We report measurements of microwave transmission over the first five Mie
resonances of alumina spheres randomly positioned in a waveguide. Though
precipitous drops in transmission and sharp peaks in the photon transit time
are found near all resonances, measurements of transmission fluctuations show
that localization occurs only in a narrow frequency window above the first
resonance. There the drop in the photon density of states is found to be more
pronounced than the fall in the photon transit time, leading to a minimum in
the Thouless number.Comment: To appear in PRL; 5 pages, including 5 figure
General boundary conditions for the envelope function in multiband k.p model
We have derived general boundary conditions (BC) for the multiband envelope
functions (which do not contain spurious solutions) in semiconductor
heterostructures with abrupt heterointerfaces. These BC require the
conservation of the probability flux density normal to the interface and
guarantee that the multiband Hamiltonian be self--adjoint. The BC are energy
independent and are characteristic properties of the interface. Calculations
have been performed of the effect of the general BC on the electron energy
levels in a potential well with infinite potential barriers using a coupled two
band model. The connection with other approaches to determining BC for the
envelope function and to the spurious solution problem in the multiband k.p
model are discussed.Comment: 15 pages, 2 figures; to be published in Phys. Rev. B 65, March 15
issue 200
Transcriptomics reveal an integrative role for maternal thyroid hormones during zebrafish embryogenesis
Thyroid hormones (THs) are essential for embryonic brain development but the genetic mechanisms involved in the action of maternal THs (MTHs) are still largely unknown. As the basis for understanding the underlying genetic mechanisms of MTHs regulation we used an established zebrafish monocarboxylic acid transporter 8 (MCT8) knock-down model and characterised the transcriptome in 25hpf zebrafish embryos. Subsequent mapping of differentially expressed genes using Reactome pathway analysis together with in situ expression analysis and immunohistochemistry revealed the genetic networks and cells under MTHs regulation during zebrafish embryogenesis. We found 4,343 differentially expressed genes and the Reactome pathway analysis revealed that TH is involved in 1681 of these pathways. MTHs regulated the expression of core developmental pathways, such as NOTCH and WNT in a cell specific context. The cellular distribution of neural MTH-target genes demonstrated their cell specific action on neural stem cells and differentiated neuron classes. Taken together our data show that MTHs have a role in zebrafish neurogenesis and suggest they may be involved in cross talk between key pathways in neural development. Given that the observed MCT8 zebrafish knockdown phenotype resembles the symptoms in human patients with Allan-Herndon-Dudley syndrome our data open a window into understanding the genetics of this human congenital condition.Portuguese Fundacao para Ciencia e Tecnologia (FCT) [PTDC/EXPL/MARBIO/0430/2013]; CCMAR FCT Plurianual financing [UID/Multi/04326/2013]; FCT [SFRH/BD/111226/2015, SFRH/BD/108842/2015, SFRH/BPD/89889/2012]; FCT-IF Starting Grant [IF/01274/2014]info:eu-repo/semantics/publishedVersio
- …