Hardy Uncertainty Principle and unique continuation properties of covariant Schrodinger flows

We prove a logarithmic convexity result for exponentially weighted $L^2$-norms of solutions to electromagnetic Schr\"odinger equation, without needing to assume smallness of the magnetic potential. As a consequence, we can prove a unique continuation result in the style of the Hardy uncertainty principle, which generalizes the analogous theorems which have been recently proved by Escauriaza, Kenig, Ponce and Vega.Comment: 26 page

La risa de José Agustín Goytisolo

Publicat a La Provincia. L'autor va enviar aquest article a Asun Carandell, veure carta GoyC/3880

Habilidades sociales y manejo de conflictos en estudiantes de sexto grado del distrito de Huaso–La Libertad, 2019

El objetivo de la tesis fue determinar la relación entre las habilidades sociales y el manejo de conflictos en estudiantes de sexto grado de primaria de las IE del distrito de Huaso – 2019. El estudio se realizó dentro del paradigma cuantitativo, el método que se utilizó fue el hipotético-deductivo. La población a investigar fueron 158 estudiantes de sexto grado de primaria de las IE del distrito de Huaso, 2019; la investigación es de tipo básica, teórica y de diseño no experimental transversal de alcance correlacional, donde se ha utilizado como instrumentos para recoger datos, la Lista de chequeo de evaluación de las habilidades sociales y el Inventario de estilos de manejo de conflictos, ambos cuestionarios son de tipo Likert con una fuerte confiabilidad. Asimismo, luego de haber desarrollado la investigación, aplicado los instrumentos y realizar el procesamiento estadístico, se llegó a la siguiente conclusión: Existe relación fuerte y significativa entre las habilidades sociales y el manejo de conflictos en estudiantes de sexto grado del distrito de Huaso, 2019, con un coeficiente de correlación de Rho Spearman = 0.879 y un p valor = .000, menor a 0,05, por lo que se acepta la hipótesis alterna y se rechaza la hipótesis nula, confirmando la relación entre las variables analizadas. Por lo tanto, se considera que los estudiantes han brindado información valiosa al haber constituido un avance en la maduración personal y el fomento de sus interrelaciones de manera positiva

Analytical Far-zone Calculation of the Field Radiated from an Equilateral Triangular Aperture

© 2019 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.This work contributes to the classical analytical models for computing the radiated electromagnetic fields from an aperture with a canonical shape by means of the equivalence principle. Analytical closed-form expressions are presented for the radiation pattern generated by the modes of an equilateral triangular aperture. The derived formulation is based on the use of the well-known equivalence principle, which provides the radiated far-field from the transversal field at the aperture. This equivalence principle is briefly described, as well as the formulation of the modal field functions associated to an equilateral triangular aperture. The equivalence principle is then applied to these modal field functions to evaluate the closedform expressions for the integrals required to obtain the radiation pattern associated to each mode. Different examples are shown, where the analytical results achieved by the formulation derived in this work are compared with those provided by commercial software packages based on different numerical approaches, showing very good agreement.This work was supported by the Spanish Government (Agencia Estatal de Investigaci´on, Fondo Europeo de Desarrollo Regional) under grant TEC2016- 76070-C3-1-R (AEI/FEDER, UE

Rigorous Modal Characterization of First- and Second-Order Symmetric Waveguides Using Specular Periodic Boundary Conditions in 2D-FEM

© 2022 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.Symmetries are widely exploited in the electromagnetic characterization of millimeter-wave devices and antennas, as they usually bring an improvement in resource usage and accuracy in full-wave simulations. Given the rising relevance of higher order symmetric devices, a challenge of integrating many different symmetries into compact formulations appears, with the objective of finding synergies and combining the strengths each one separately brings. In this work, we present a 2-D finite element method (FEM) formulation that fulfills this task for arbitrary waveguide cross sections presenting at the same time specular first-order and rotational second-order symmetries. It is based on newly introduced specular periodic boundary conditions (SPBCs), which effectively exploit the best case simulation domain for this problem. Furthermore, they avoid the need of using a mesh matching or projection procedure for periodic boundaries, while also bringing an improvement to mode classification

Estudio antropométrico longitudinal en escolares malagueños desde los 9 a los 12 años de edad

El artículo trata sobre un estudio antropométrico en niños de 9 a 12 años realizado en cuatro colegios de la provincia de Málaga. Es un trabajo longitudinal de más de dos años de duración iniciado con niños de cuarto de primaria, un total de 294. Se ha utilizado la metodología más actualizada en análisis morfológico. La evolución lineal de los parámetros antropométricos apunta a un mayor desarrollo de las niñas frente a los niños sobre todo entre los 10,6 y los 11,2 años. No obstante los diámetros óseos masculinos son en todo momento superiores a los femeninos. Destacar la aplicabilidad del estudio de cara a la prevención de problemas físicos como la obesidad y su enfoque didáctico a través de hábitos de vida sanos

Computerized adaptive test and decision trees: A unifying approach

In the last few years, several articles have proposed decision trees (DTs) as an alternative to computerized adapted tests (CATs). These works have focused on showing the differences between the two methods with the aim of identifying the advantages of each of them and thus determining when it is preferable to use one method or another. In this article, Tree-CAT, a new technique for building CATs is presented. Unlike the existing work, Tree-CAT exploits the similarities between CATs and DTs. This technique allows the creation of CATs that minimise the mean square error in the estimation of the examinee’s ability level, and controls the item’s exposure rate. The decision tree is sequentially built by means of an innovative algorithmic procedure that selects the items associated with each of the tree branches by solving a linear program. In addition, our work presents further advantages over alternative item selection techniques with exposure control, such as instant item selection or simultaneous administration of the test to an unlimited number of participants. These advantages allow accurate on-line CATs to be implemented even when the item selection method is computationally costly.Numerical experiments were conducted in Uranus, a supercomputer cluster located at Universidad Carlos III de Madrid and jointly funded by EU-FEDER funds and by the Spanish Government via the National Projects No. UNC313-4E-2361, No. ENE2009-12213- C03-03, No. ENE2012-33219, No. ENE2012-31753 and No. ENE2015-68265-P

Functional explanation of extreme hatching asynchrony: Male Manipulation Hypothesis

Hatching asynchrony in birds is considered an adaptation to facilitate brood reduction because under conditions of food scarcity, the smallest nestling usually dies soon after hatching, thereby minimizing parental effort. However, in species with extreme hatching asynchrony, the last hatchlings paradoxically experience a very low probability of survival and death can take so long that it can hardly be considered an adaptation. Here, we propose and experimentally tested a new adaptive hypothesis explaining the brood reduction paradox, namely the “Male Manipulation Hypothesis”. Our hypothesis suggests that by inducing asynchronous hatching, females increase the feeding requirements of the brood, which will induce males to increase provisioning effort. In addition, females may extend the period of male manipulation by feeding the smallest nestling just enough to sustain life. Our study showed that male common blackbirds (Turdus merula) increased their effort (i.e., number of food items per hour) in experimental asynchronous broods compared to synchronous broods, while females reduced their contribution, as predicted by the hypothesis