Factorization of J-expansive meromorphic operator-valued functions

AbstractThe factorization theorems are a generalization for J-biexpansive meromorphic operator-valued functions on an infinite-dimensional Hilbert space of the theorems on decomposition of J-expansive matrix functions on a finite-dimensional Hilbert space due to A. V. Efimov and V. P. Potapov [Uspekhi Mat. Nauk 28 (1973), 65–130; Trudy Moskov. Mat. Obšč. 4 (1955), 125–236]. They also generalize theorems on factorization of J-expansive meromorphic operator functions due to Ju. P. Ginzburg [Izv. Vysš. Učebn. Zaved. Matematika 32 (1963), 45–53]. Within the framework of generalized network theory, the results can be applied to the J-biexpansive real operators that characterize a Hilbert port. Application of the extraction procedure to a given real operator leads to its splitting into a product of real factors, corresponding to Hilbert ports of a simpler structure. This can be interpreted as an extension of the classical method of synthesis of passive n-ports by factor decomposition

Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)

This aim of paper is to presents the development of a multidisciplinary project carried out by the cooperation between Politecnico di Torino and ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The goal of the project was the training in geospatial data acquiring and processing for students attending Architecture and Engineering Courses, in order to start up a team of "volunteer mappers". Indeed, the project is aimed to document the environmental and built heritage subject to disaster; the purpose is to improve the capabilities of the actors involved in the activities connected in geospatial data collection, integration and sharing. The proposed area for testing the training activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According to other international experiences, the group is expected to be active after emergencies in order to upgrade maps, using data acquired by typical geomatic methods and techniques such as terrestrial and aerial Lidar, close-range and aerial photogrammetry, topographic and GNSS instruments etc.; or by non conventional systems and instruments such us UAV, mobile mapping etc. The ultimate goal is to implement a WebGIS platform to share all the data collected with local authorities and the Civil Protectio

New theoretical and observational results on transverse magnetic fluctuations near the magnetopause

Electromagnetic ion cyclotron waves in the plasma depletion layer measured by Wind on three inbound passes of the magnetosheath near the stagnation streamline are modeled using theoretical results from Gnavi et al., J. Geophys. Res., 105, 20973, 2000. The kinetic dispersion relation in a plasma composed of electrons, protons, and alpha particles, is solved with each species modeled by a bi-Maxwellian distribution function with parameters taken from observations, where available, and from average values found in the literature. While one pass was under substantially high solar wind dynamic pressure (~ 6.4 nPa), the other two passes were under normal dynamic pressure at 1 AU (~ 2.2 nPa). The presence of electromagnetic ion cyclotron waves in the terrestrial plasma depletion layer under normal dynamic pressure is documented and analyzed for the first time. The power spectral density of the magnetic fluctuations transverse to the background field, using high resolution (~ 11 samples/s) data from the Magnetic Field Investigation, is obtained for the inner, middle and outer regions of the plasma depletion layer. The analysis of spectra and comparison with theory is extended to the normal dynamic pressure regime. The observations show that at the inner plasma depletion layer position the spectral power density weakens as the dynamic pressure decreases, and that the frequency range of emission shifts downward with diminishing pressure. Using bipolytropic laws for the anisotropic magnetosheath, we argue that the effect of a reduction of Pdyn is to lower Ap, thereby weakening the driver of EICWs leading to marginally bifurcated spectra and weaker EICW activity in the PDL under typical conditions. Qualitative and in some cases quantitative agreement between theory and data is very good

On the MHD boundary of Kelvin-Helmholtz stability diagram at large wavelengths

Working within the domain of inviscid incompressible MHD theory, we found that a tangential discontinuity (TD) separating two uniform regions of different density, velocity and magnetic field may be Kelvin-Helmholtz (KH) stable and yet a study of a transition between the same constant regions given by a continuous velocity profile shows the presence of the instability with significant growth rates. Since the cause of the instability stems from the velocity gradient, and since a TD may be considered as the ultimate limit of such gradient, the statement comes as a surprise. In fact, a long wavelength (lambda) boundary for the KH instability does not exist in ordinary liquids being instead a consequence of the presence of magnetic shear, a possibility that has passed unnoticed in the literature. It is shown that KH modes of a magnetic field configuration with constant direction do not have the long lambda boundary. A theoretical explanation of this feature and examples of the violation of the TD stability condition are given using a model that can be solved in closed form. Stability diagrams in the (kd, MA) plane are given (where kd = 2pid/lambda, 2d is the velocity gradient length scale, and MA is the Alfvénic Mach number) that show both the well-known limit at small lambdas and the boundary for large but finite lambdas noted here. Consequences of this issue are relevant for stability studies of the dayside magnetopause as the stability condition for a TD should be used with care in data analysis work

Ansiedad y evitación en exámenes orales eficacia de una intervención grupal para estudiantes universitarios

Los exámenes orales son situaciones sociales que promueven la activación de emociones displacenteras como la ansiedad y la vergüenza. Para sobrellevar dichas emociones, los estudiantes emplean diferentes conductas de afrontamiento, tales como incrementar la preparación, practicar, buscar apoyo con fines emocionales o instrumentales o practicar relajación. Sin embrago, un importante grupo de alumnos, para mitigar el malestar emocional recurre a conductas de evitación que, si bien generan alivio inicial, traen aparejadas consecuencias desfavorables a mediano plazo. Cuando se torna frecuente, la evitación en exámenes orales (EEO) configura un cuadro que difícilmente remite espontáneamente. Entre quienes presentan elevadas ansiedad y evitación de exámenes orales se observan además disminuciones en el rendimiento académico, demora en la carrera, crisis vocacionales y es frecuente constatar la presencia de diversos síntomas de ansiedad, depresión, somatizaciones e inestabilidad emocional. Por ello, se formuló un programa grupal para abordar la ansiedad frente a los exámenes (AE) y la EEO en estudiantes universitarios, usando un enfoque cognitivo– comportamental. La intervención incluyó 10 encuentros de frecuencia semanal y combinó estrategias de psicoeducación, reestructuración cognitiva, relajación, exposición ensayo conductual, auto instrucciones y técnicas de defusiónOral exams are social situations that promote unpleasant emotions like anxiety or shame. Coping behaviour are used to alleviate emotional distress. Avoidance is immediately effective but dysfunctional to pursuit academic goals. Cognitive behavioural intervention program was designed to alleviate test anxiety and reverse avoidance behaviour in oral test, to college students. Program includes 10 encounters and employed techniques of relaxation, cognitive restructuring, behaviour essay and self-instructions. A research was conducted to evaluate the efficacy of intervention program. Quasi experimental design was employed with participation of 30 college students. Self-reports of test anxiety, avoidance and mental symptoms were applied. Pre post differences (N=17) were estimated using Wilcoxon test and cliff delta indices. Significant decrements were corroborated in total TA (Z -3,46 p <,01 D=,82) Emotionality, (Z -3,34 p<,01 D=,65), Worry (Z -3,32 p<,01 D=,65), Interference (Z -2,87 p<,01 D=,53), postponement (Z -3,62 p<,001 D=,1) and oral expression inhibition (Z -3,63 p<,001 D=,1). Intervention has positive and differential impact depending the test anxiety or avoidance dimension considered. Some participants has high decrements and other small. Mental symptoms were no correlated with the observed differences pre post between cases. Qualitative data collected in follow up interviews were congruent with quantitative results.Mesa de trabajos libres: Psicología y EducaciónFacultad de Psicologí

Emociones, afrontamiento y autorregulación en el contexto de una evaluación no tradicional

Los objetivos de este trabajo son describir y analizar las emociones, estrategias de afrontamiento y mecanismos de autorregulación ante una situación de examen no tradicional dentro de la carrera de arquitectura de la UNC, para lo cual se realizó un estudio de tipo exploratorio empleando una estrategia flexible de indagación que permitiera identificar aspectos relevantes del problema a investigar.The objectives of this study are describing and analyzing emotions, coping mechanisms and self-regulation mechanisms ahead of an unconventional testing situation in the architecture degree course at UNC.Mesa de trabajos libres: Psicología y EducaciónFacultad de Psicologí

Emociones, afrontamiento y autorregulación en el contexto de una evaluación no tradicional

Los objetivos de este trabajo son describir y analizar las emociones, estrategias de afrontamiento y mecanismos de autorregulación ante una situación de examen no tradicional dentro de la carrera de arquitectura de la UNC, para lo cual se realizó un estudio de tipo exploratorio empleando una estrategia flexible de indagación que permitiera identificar aspectos relevantes del problema a investigar.The objectives of this study are describing and analyzing emotions, coping mechanisms and self-regulation mechanisms ahead of an unconventional testing situation in the architecture degree course at UNC.Mesa de trabajos libres: Psicología y EducaciónFacultad de Psicologí