On the use of the l(2)-norm for texture analysis of polarimetric SAR data

In this paper, the use of the l2-norm, or Span, of the scattering vectors is suggested for texture analysis of polarimetric synthetic aperture radar (SAR) data, with the benefits that we need neither an analysis of the polarimetric channels separately nor a filtering of the data to analyze the statistics. Based on the product model, the distribution of the l2-norm is studied. Closed expressions of the probability density functions under the assumptions of several texture distributions are provided. To utilize the statistical properties of the l2-norm, quantities including normalized moments and log-cumulants are derived, along with corresponding estimators and estimation variances. Results on both simulated and real SAR data show that the use of statistics based on the l2-norm brings advantages in several aspects with respect to the normalized intensity moments and matrix variate log-cumulants.Peer ReviewedPostprint (published version

Analisis de funciones mediante wavelets y su aplicacion a la compresion de imagenes sar

Peer ReviewedPostprint (published version

Análisis de funciones mediante wavelets y su aplicación a la compresión de imágenes SAR

Peer Reviewe

Análisis de funciones mediante wavelets y su aplicación a la compresión de imágenes SAR

Peer Reviewe

Zero-thickness interface model with chemical degradation by acid attack

Carbon dioxide (CO2) storage in abandoned oil/gas reservoirs is considered a viable alternative to reduce greenhouse gas emissions to the atmosphere. An important element of the risk associated with long-term CO2 storage is the loss of integrity of the cement seals of the abandoned wells in the reservoir. Among others, one possible cause of loss of integrity is the degradation of the oil-well cement due to the acid attack of the carbonated brine in the reservoir. In previous studies, the authors have developed a diffusion-reaction model for simulating this degradation process. In order to study possible coupled Chemo-Mechanical (CM) mechanisms, this model will be coupled with an existing mechanical model. For this purpose, in this paper, an existing constitutive law for zero-thickness interface, based on the theory of elasto-plasticity with concepts of fracture mechanics, is modified to incorporate the effect of chemical degradation on the mechanical strength parameters. Preliminary results obtained with this new constitutive law are presented, in order to illustrate the main aspects of the proposed constitutive law, as well as a possible C-M degradation mechanism that should be considered in the long-term safety assessment of CO2 geological storage projects

Testing for linear and quadratic effects between price adaptation and export performance: The impact of values and perceptions

Managerial perceptions are essential in explaining strategic decisions. It is, therefore, surprising that despite the number of studies that have examined the impact of managerial characteristics in exporting, little research has been reported in the export literature that investigates the importance of managers' perceptions on strategic decisions and resultant performance outcomes. To address this gap in the literature, the authors examine the key determinants of managers' psychic distance as well as its influence on international pricing decisions, and this in turn, on the export performance of SMEs. We also examine the quadratic effects of price adaptation on export performance. This is particularly relevant since price adaptation and export performance have been assumed in the literature to have a linear relationship. The results show that managers' perceptions have a significant impact on pricing decisions and resultant performance outcomes. Our findings also indicate that price adaptation has an inverted U-shaped relationship with export performance

On the extension of multidimensional speckle noise model from single-look to multilook SAR imagery

Speckle noise represents one of the major problems when synthetic aperture radar (SAR) data are considered. Despite the fact that speckle is caused by the scattering process itself, it must be considered as a noise source due to the complexity of the scattering process. The presence of speckle makes data interpretation difficult, but it also affects the quantitative retrieval of physical parameters. In the case of one-dimensional SAR systems, speckle is completely determined by a multiplicative noise component. Nevertheless, for multidimensional SAR systems, speckle results from the combination of multiplicative and additive noise components. This model has been first developed for single-look data. The objective of this paper is to extend the single-look data model to define a multilook multidimensional speckle noise model. The asymptotic analysis of this extension, for a large number of averaged samples, is also considered to assess the model properties. Details and validation of the multilook multidimensional speckle noise model are provided both theoretically and by means of experimental SAR data acquired by the experimental synthetic aperture radar system, operated by the German Aerospace Center.Peer Reviewe

Coherence estimation in synthetic aperture radar data based on speckle noise modeling

In the past we proposed a multidimensional speckle noise model to which we now include systematic phase variation effects. This extension makes it possible to define what is believed to be a novel coherence model able to identify the different sources of bias when coherence is estimated on multidimensional synthetic radar aperture (SAR) data. On the one hand, low coherence biases are basically due to the complex additive speckle noise component of the Hermitian product of two SAR images. On the other hand, the availability of the coherence model permits us to quantify the bias due to topography when multilook filtering is considered, permitting us to establish the conditions upon which information may be estimated independently of topography. Based on the coherence model, two coherence estimation approaches, aiming to reduce the different biases, are proposed. Results with simulated and experimental polarimetric and interferometric SAR data illustrate and validate both, the coherence model and the coherence estimation algorithms.Peer Reviewe

Embedded optimization-based controllers for industrial processes

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Due to the growth of computational capabilities and the proliferation of field-programmable gate arrays (FPGA), the utilization of model predictive control (MPC) for embedded applications in the industry has become a possibility and a fact. This paper presents and discusses the possibilities of the use of online MPC, embedded in an educational device from National Instruments, using two different optimization algorithms and code generators, which have come out in recent years by the academia: CVXGEN, which implements a primal-dual interior-point algorithm, and qpOASES, which relies on the online active-set strategy algorithm. Both algorithms have been tested both in simulation and in real-time experimentation to control a four-tank pilot plant.Peer ReviewedPostprint (author's final draft

Los cuasicristales muestran simetrías descritas por un mineralogista del siglo XVIII : [entrevista realizada por la Oficina de Transferencia de Resultados de Investigación (OTRI), Unidad de Información Científica y Divulgación de la Investigación, de la Universidad Complutense de Madrid a los profesores María Victoria López-Acevedo Cornejo y Carlos Pina Martínez, de la Facultad de Ciencias Geológicas de la UCM]

Tanto los cristales como los cuasicristales están formados por infinidad de átomos ordenados. La diferencia radica en que, en los primeros, este orden es periódico, mientras que en los cuasicristales, no lo es y muestran simetrías consideradas “prohibidas” en la Cristalografía. Su descubrimiento fue merecedor del Premio Nobel de Química en 2011. Curiosamente, dos siglos antes, el científico francés Jean-Baptiste Romé de L´Isle construyó una seriede modelos con la simetría de los cuasicristales. Victoria López-Acevedo y Carlos Manuel Pina, investigadores de la facultad de Ciencias Geológicas de la Universidad Complutense de Madrid (UCM), han analizado las morfologías cuasicristalinas descritas por Romé, tratando de esclarecer cómo pudo tener esta premonición científic