Paving the Way for Temporal Grounding

In this paper we consider the problem of introducing variables in temporal logic programs under the formalism of Temporal Equilibrium Logic (TEL), an extension of Answer Set Programming (ASP) for dealing with linear-time modal operators. We provide several fundamental contributions that pave the way for the implementation of a grounding process, that is, a method that allows replacing variables by ground instances in all the possible (or better, relevant) ways

Actualización en malformaciones venosas

Venous malformations represent 2/3rds of all vascular malformations and are frequently much more complex than they appear to be. Patients with large venous malformations require a deep analytical and radiological study, as well as specific treatment to control any possible localised intravascular coagulation. If the lesions are extensive, especially in the lower member, a study should be made to detect the presence of an underlying osteoporosis with the idea of preventing pathological fractures. Equally, a check must be made for arthropathy, and an early prophylactic synovectomy must be considered when the radiological extension makes this advisable, with the idea of avoiding irreversible damage to the joints with the passage of time. Currently, microfoam scleropathy is favoured as the treatment of choice for low-flow vascular malformations. In the not too distant future, the use of selective antiangiogenic medicines, besides low-molecularweight heparins

Aplicación de la técnica SVM en el análisis forense de imágenes de dispositivos móviles

Uno de los problemas a tratar dentro del análisis forense digital es la identificación de la cámara que se ha usado para obtener una determinada imagen. Debido al aumento en el uso de teléfonos móviles con cámara integrada durante los últimos años, el trabajo está orientado a este tipo de dispositivos, proporcionando al investigador forense una herramienta específica para el análisis de este tipo de imágenes. En este trabajo se analiza la información EXIF contenida en un archivo de imagen y se comprueba porque no es una fuente fiable a la hora de obtener la marca y modelo de la cámara. Por eso desarrollamos un algoritmo que utiliza la información de los píxeles de la imagen. Está basado en las diferencias existentes en los métodos de procesamiento de la imagen que utilizan los distintos fabricantes, como el algoritmo de interpolación del color que tiene lugar en la matriz CFA del sensor, la corrección gamma o la corrección de puntos blancos. Estas diferencias originan un conjunto de huellas en la imagen que nos permitirían diferenciar la marca y modelo de la camara fuente. Para obtener estas huellas, extraemos un conjunto de características de las imagenes, entre las que se encuentran características de color, métricas de la calidad de la imagen y estadísticas wavelet. Para realizar la predicción de la marca y modelo de la camara utilizamos un clasificador SVM. Siguiendo un procedimiento análogo, se desarrolla otro algoritmo que permite saber si una imagen procede de una cámara o de un escáner. Finalmente, llevamos a cabo un conjunto de experimentos que demuestran la efectividad del algoritmo implementado. [ABSTRACT] One of the issues involved in digital forensics is the identification of the camera used to obtain a particular image. Due to the increase use of mobile phones with integrated camera in recent years, this work is aimed at this type of devices, providing to forensic investigator a specific tool for the analysis of images taken with mobile phones. In this work we analyze the EXIF information contained in an image file and we explain because it is not a reliable source if we want to extract the make and model of the camera from it. So we develop an algorithm that uses information from the pixels of the image. It is based on dferences in the image processing methods used by diferent manufacturers, such as color interpolation algorithm which takes place in the color filter array, gamma correction or white point correction. These diferences originate a set of footprints in the image that allow us to diferentiate the brand and model of the source camera. To obtain these footprints, we extract a feature set from the images, among which are color characteristics, image quality metrics and wavelet statistics. To predict the make and the model of camera we use an SVM classifier. Following a similar procedure, we develop another algorithm that let us know if an image comes from a camera or a scanner. Finally, we perform a series of experiments to prove the efectiveness of the implemented algorithm

Pressure-induced Jahn-Teller suppression and simultaneous high-spin to low-spin transition in the layered perovskite CsMnF4

The interplay between the orbital ordering and the spin state in Jahn-Teller Mn3+ governing the optical, magnetic, and transport properties in the layered CsMnF4 perovskite is investigated. Such electronic effects are strongly coupled to the lattice and thus can be modified by external pressure. However, there is very little understanding of the structural conditions which are required to attain spin crossover in connection with the electronic structure of Mn3+. The distortion, spin state, and tilting of MnF6 octahedra in the insulating ferromagnet CsMnF4 are jointly studied by high-pressure optical spectroscopy. The insulating character of CsMnF4 allowed us to explore the electronic structure associated with the 3d levels of Mn3+ in the 0–46 GPa pressure range, an information which is obscured in most oxides due to metallization at high pressure. We show that the spin-crossover transition, related to the spin change, S=2→1, in Mn3+, takes place at 37 GPa with the simultaneous suppression of the axially elongated distortion associated with the Jahn-Teller effect. The wide stability pressure range of the Jahn-Teller distortion and high-spin state is explained in terms of crystalfield models including the Jahn-Teller stabilization energy. On this basis, we discuss the interplay between spin transition and Jahn-Teller effect comparing present findings with other results attained in Mn3+, Ni3+, and Co3

Pressure effects on NaMnF4: Structural correlations and Jahn-Teller effect from crystal-field spectroscopy

This work investigates the optical absorption spectrum of the NaMnF4-layered perovskite and its variation with pressure. The spectrum basically consists of three broadbands located at 1.916, 2.263, and 2.817 eV, which correspond to the crystal-field (CF) transitions 5B1g⃗5Γi (Γi=A1g, B2g, and Eg) with the Jahn-Teller- (JT-) distorted MnF63- complex (Mn3+ d4 configuration). In addition, there are two spin-flip 5B1g⃗3B1g peaks at 2.397 and 2.890 eV, which are activated by the exchange mechanism. Their variation with pressure reveals that the JT energy does not change significantly with pressure: ∂EJT/∂P=0.8 meV/GPa. Furthermore, the variation of the JT tetragonal splitting of the parent octahedral eg and t2g, termed Δe and Δt, respectively, clearly indicate that ∂Δe/∂P≪∂Δt/∂P, although Δe≈4Δt. The CF energies and their pressure shift are explained in terms of local structural changes within the MnF63- complex induced by pressure. The structural correlation analysis reveals that the reduction of the MnF63- JT distortion is smaller than the expected one on the basis of the crystal volume reduction, thus indicating tilt phenomena. This interpretation is supported by the decrease of in-layer Mn-F-Mn superexchange, such as is derived from the optical spectra. We demonstrate that the equatorial and axial distances decrease from 1.839 to 1.808 Å and from 2.167 to 2.107 Å, respectively, in the 0–10 GPa range

Kondo effect in a double quantum-dot molecule under the effect of an electric and magnetic field

Electron tunneling through a double quantum dot molecule, in the Kondo regime, under the effect of a magnetic field and an applied voltage, is studied. This system possesses a complex response to the applied fields characterized by a tristable solution for the conductance. The different nature of the solutions are studied in and out thermodynamical equilibrium. It is shown that the interdot coupling and the fields can be used to control the region of multistability. The mean-field slave-boson formalism is used to obtain the solution of the problem.Comment: 5 pages, 4 figures. To appear in Sol. State Com