Structured Output SVM for Remote Sensing Image Classification

Traditional kernel classifiers assume independence among the classification outputs. As a consequence, each misclassification receives the same weight in the loss function. Moreover, the kernel function only takes into account the similarity between input values and ignores possible relationships between the classes to be predicted. These assumptions are not consistent for most of real-life problems. In the particular case of remote sensing data, this is not a good assumption either. Segmentation of images acquired by airborne or satellite sensors is a very active field of research in which one tries to classify a pixel into a predefined set of classes of interest (e.g. water, grass, trees, etc.). In this situation, the classes share strong relationships, e.g. a tree is naturally (and spectrally) more similar to grass than to water. In this paper, we propose a first approach to remote sensing image classification using structured output learning. In our approach, the output space structure is encoded using a hierarchical tree, and these relations are added to the model in both the kernel and the loss function. The methodology gives rise to a set of new tools for structured classification, and generalizes the traditional non-structured classification methods. Comparison to standard SVM is done numerically, statistically and by visual inspection of the obtained classification maps. Good results are obtained in the challenging case of a multispectral image of very high spatial resolution acquired with QuickBird over a urban area.     

Beyond Intercalation‐Based Li‐Ion Batteries: The State of the Art and Challenges of Electrode Materials Reacting Through Conversion Reactions

Despite the imminent commercial introduction of Li‐ion batteries in electric drive vehicles and their proposed use as enablers of smart grids based on renewable energy technologies, an intensive quest for new electrode materials that bring about improvements in energy density, cycle life, cost, and safety is still underway. This Progress Report highlights the recent developments and the future prospects of the use of phases that react through conversion reactions as both positive and negative electrode materials in Li‐ion batteries. By moving beyond classical intercalation reactions, a variety of low cost compounds with gravimetric specific capacities that are two‐to‐five times larger than those attained with currently used materials, such as graphite and LiCoO₂, can be achieved. Nonetheless, several factors currently handicap the applicability of electrode materials entailing conversion reactions. These factors, together with the scientific breakthroughs that are necessary to fully assess the practicality of this concept, are reviewed in this report.     

Inhibitory effect of melanins from Agaricus bisporus polyphenol oxidase and two different substrates on carboxypeptidases A and B activity

In recent years, some beneficial effects on health of melanins that are formed as a result of polyphenol oxidase action have been discovered. However, it is also known that similar polymers have a detrimental effect on proteases activity. Thus, the aim of this work was to assay whether melanins from two different substrates act as carboxypeptidase A and carboxypeptidase B inhibitors. It was found that melanin synthesized from l-tyrosine decreases both the apparent affinity between carboxypeptidases and their substrates and the maximum reaction rate. Consequently, it is possible to conclude that these melanins inhibit CPA and CPB activity in a mixed way. On the contrary, no inhibition was found in the case of melanin synthesized from 4-methylcatechol.     

Regional economic dynamics and convergence in the European Union

This paper uses an alternative approach to convergence analysis, which, in our opinion, is richer than those traditionally proposed. We believe that the evolution of the whole regional distribution is what matters, not that of an average or representative economy, implicit in the or convergence concepts. Moreover, when analyzing inequality among regional economies, geographic space acquires a preeminent role. We therefore apply spatial association tests recently developed in the spatial econometrics literature and relate them to convergence analysis. Specifically, we apply this methodology to the analysis of regional dynamics and convergence in the European Union (EU). In this context, the progress made in the integration process has highlighted the question of economic disparities at regional level. The process of convergence came to an end in the late seventies, coinciding with major changes in economic activity. This paper shows how these factors appear to have provoked a regionally differentiated response which, though significant, did not, in all likelihood, exacerbate the decrease in regional inequalities.     

Isothermal crystallization study on a biodegradable segmented copolymer constituted by glycolide and trimethylene carbonate units

The isothermal crystallization behavior of a segmented copolymer constituted by hard blocks of polyglycolide and soft segments derived from the copolymerization of glycolide and trimethylene carbonate was investigated. This polymer has applied relevance because it is one of the most widely used for bioabsorbable surgical sutures. Calorimetric, optical microscopy, and infrared techniques were combined to understand the thermal properties and the different factors that influence the crystallization process. Basically, only the hard blocks crystallized, although certain processing conditions allowed performing an additional crystallization associated with small lamellar domains of the soft segment. Crystallization from both the melt and the glass state rendered positive spherulites with a fibrillar texture. The observed unusual sign of birefringence was a consequence of the close packing structure of polyglycolide, which was also corroborated by electron diffraction patterns. Crystallization was characterized by an athermal nucleation, which allowed accurate estimation of the secondary nucleation parameter by using the calorimetric data only. Significant differences in the Avrami exponent (from 2.32 to 1.45) were found between the cold and hot isothermal crystallizations. The stronger geometric constraints observed in the crystallization from the glass state were also corroborated by FTIR analyses. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

On the accuracy of the diffusion coefficient measurements using different initial shear cell configurations at low and moderate Rayleigh numbers

Three different shear cell arrangements are considered here in order to discuss and compare the accuracy of their measurements at low and moderate Rayleigh number, that is to say, in reduced gravity environments. To do so, specific numerical procedures have been designed in order to quantitatively estimate the corresponding associated errors as a function of time and at the end of the diffusive process. The present work clearly shows that the interdiffusion-couple configuration is, from the point of view of accuracy, the worst one.     

Antioxidant properties of garden strawberry leaf extract and its effect on fish oil oxidation

The present study characterises garden strawberry leaf extract and reports its effect on shelf life and quality characteristics of fish oil. Radical scavenging capacity of the extract in DPPH^? and ABTS^?+ assays was equivalent to 1207 and 1579 μmol g^?1 of trolox equivalents, respectively, total phenolic content was 257 mg g^?1 of gallic acid equivalents. Phenolic and volatile constituents were analysed by liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS). The extract was added to fish oil and its oxidation was followed during 42 days: peroxide, p‐anisidine values and hexanal concentration were lower in the samples with extract, particularly at the end of storage. The effect of extract on fatty acid composition was not significant, however the changes in the percentages of some individual acids were observed. Fish oil containing 5% of extract had lower levels of lipid oxidation in comparison to other samples. The results indicate that strawberry leaves could be a potential source of natural antioxidants.