Sequential non-rigid structure from motion using physical priors

© 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.We propose a new approach to simultaneously recover camera pose and 3D shape of non-rigid and potentially extensible surfaces from a monocular image sequence. For this purpose, we make use of the Extended Kalman Filter based Simultaneous Localization And Mapping (EKF-SLAM) formulation, a Bayesian optimization framework traditionally used in mobile robotics for estimating camera pose and reconstructing rigid scenarios. In order to extend the problem to a deformable domain we represent the object's surface mechanics by means of Navier's equations, which are solved using a Finite Element Method (FEM). With these main ingredients, we can further model the material's stretching, allowing us to go a step further than most of current techniques, typically constrained to surfaces undergoing isometric deformations. We extensively validate our approach in both real and synthetic experiments, and demonstrate its advantages with respect to competing methods. More specifically, we show that besides simultaneously retrieving camera pose and non-rigid shape, our approach is adequate for both isometric and extensible surfaces, does not require neither batch processing all the frames nor tracking points over the whole sequence and runs at several frames per second.Peer ReviewedPostprint (author's final draft

Behavioral and Personality Predictors of Acceptance and Rejection in University

A aceitação e a rejeição no grupo associam-se tanto a características de personalidade como às habilidades sociais e são mais estudadas em crianças que em estudantes universitários. O objetivo deste estudo foi investigar se a aceitação e rejeição estariam mais associadas a tendências de personalidade, mais especificamente à socialização ou às habilidades sociais. Participaram 187 estudantes universitários dos cursos de Educação Física (67%) e Psicologia (32%). Os instrumentos utilizados foram o Teste Sociométrico, a Escala Fatorial de Socialização e o Inventário de Habilidades Sociais. Observou-se efeito de moderação do sexo na relação entre assertividade e aceitação e rejeição para sair em universitários. As habilidades sociais foram melhores preditores da aceitação e rejeição social no grupo de universitários.La aceptación y el rechazo en el grupo se relacionan a las características de la personalidad y a las habilidades sociales, pero sin tener en cuenta la relación entre las habilidades sociales y personalidad. Además, los estudios son más centrados en los niños y no en los estudiantes universitarios. El objetivo fue investigar si la aceptación y el rechazo se asocian más con las tendencias de personalidad, específicamente con la socialización o las habilidades sociales. Recolectamos datos de 187 estudiantes universitarios de los cursos de Educación Física (67%) y Psicología (32%). Los instrumentos utilizados fueron la prueba sociométrico, la Escala Factorial de Socialización y el Inventario de las Habilidades Sociales. Se observó un efecto de moderación de género en la relación entre la asertividad y la aceptación y el rechazo para salir en la universidad. Las habilidades sociales son mejores predictores de la aceptación y del rechazo social en el grupo de estudiantes universitarios.Acceptance and rejection in the group are related to both personality characteristics and social skills and most studies focus on children instead of college students. The objective of this study was to investigate whether acceptance and rejection would be more associated with personality tendencies, specifically socialization or social skills. We collected data from 187 college students attending the Physical Education (67%) and Psychology (32%) courses. The instruments were the sociometric test, the Factorial Scale of Socialization and the Social Skills Inventory. A moderating effect of gender in the relationship between assertiveness and acceptance and rejection to go out on college was observed. Social skills were better predictors of acceptance and social rejection in the university group

Real-time 3D reconstruction of non-rigid shapes with a single moving camera

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper describes a real-time sequential method to simultaneously recover the camera motion and the 3D shape of deformable objects from a calibrated monocular video. For this purpose, we consider the Navier-Cauchy equations used in 3D linear elasticity and solved by finite elements, to model the time-varying shape per frame. These equations are embedded in an extended Kalman filter, resulting in sequential Bayesian estimation approach. We represent the shape, with unknown material properties, as a combination of elastic elements whose nodal points correspond to salient points in the image. The global rigidity of the shape is encoded by a stiffness matrix, computed after assembling each of these elements. With this piecewise model, we can linearly relate the 3D displacements with the 3D acting forces that cause the object deformation, assumed to be normally distributed. While standard finite-element-method techniques require imposing boundary conditions to solve the resulting linear system, in this work we eliminate this requirement by modeling the compliance matrix with a generalized pseudoinverse that enforces a pre-fixed rank. Our framework also ensures surface continuity without the need for a post-processing step to stitch all the piecewise reconstructions into a global smooth shape. We present experimental results using both synthetic and real videos for different scenarios ranging from isometric to elastic deformations. We also show the consistency of the estimation with respect to 3D ground truth data, include several experiments assessing robustness against artifacts and finally, provide an experimental validation of our performance in real time at frame rate for small mapsPeer ReviewedPostprint (author's final draft

Educational challenges of emerging risks in cyberspace: foundations of an appropriate strategy for preventing online child victimisation

In just a few years, technological changes have transformed how people interact and communicate with each other, in particular among so-called digital adolescents. The impact of technology on routine activities and mainstream culture has led to an increase in young peoples’ exposure to psychological and criminological risks. As a result of this new psychosocial trend, new educational challenges are appearing and it is becoming more necessary to react to these challenges on the basis of an adequate diagnosis of psychology and pedagogy relating to adolescents. Criminological theories and research have tried to identify risk and protection factors to understand victimisation processes in more depth and improve prevention strategies. In this context, it is necessary to develop educational programs that consider personal, familial, and situational vulnerabilities and weaknesses in order to foster resilient individuals who can successfully confront the risks inherent to cyberspace. By analysing specific forms of cybervictimisation, guidelines based on criminological research and the most frequent victimisation processes will be identified in order to improve design of educational programs focused on parents, educators and potential victims.El avance tecnológico ha transformado en pocos años la forma de interactuar y comunicarse entre las personas, especialmente entre los denominados adolescentes digitales. Su impacto en las actividades cotidianas y en la cultura dominante ha propiciado, asimismo, un incremento en la exposición a riesgos psicológicos y criminológicos por parte de los menores. Ante esta nueva realidad psicosocial, se plantean nuevos retos educacionales que deben partir de un adecuado diagnóstico de la psicología y pedagogía en relación con los adolescentes. Las teorías e investigaciones criminológicas vienen tratando de identificar los factores de riesgo y de protección con la finalidad de comprender con mayor profundidad los procesos de victimización y mejorar las estrategias de prevención. En este contexto, conviene avanzar en programas educativos que tengan en cuenta las carencias y vulnerabilidades personales, familiares y situacionales de los menores, a fin de fomentar el desarrollo de personas resilientes que sepan afrontar con éxito los riesgos que se fraguan y surgen en el ciberespacio. Mediante el análisis de las concretas formas de cibervictimización se pretende señalar algunas pautas basadas en la investigación criminológica y en los procesos de victimización más frecuentes en los entornos en que se desenvuelven los menores, de modo que puedan servir en el diseño de los programas educativos dirigidos a padres, educadores y potenciales víctimas

Oral health survey of the child population in the Valencia Region of Spain (2004)

Introducción (fundamento y objetivo): La finalidad de establecer una periodicidad sexenal para estudiar la evolución de salud oral infantil unido a importantes cambios demográficos asociados con la inmigración en la Comunidad Valenciana han motivado este trabajo. Material y método: Con una muestra seleccionada al azar de 509 niños de 6 años, 478 de 12 años y 401 de 15-16 años se ha realizado un estudio de corte transversal. Los exploraciones clínicas fueron realizadas por odontólogos calibrados (Kappa > 0.85). Resultados: La prevalencia de caries en dentición temporal a los 6 años es del 32% (Icod=1.08) y en dentición permanente es de 42.5% a los 12 años (ICAOD=1.07) y del 55.9% a los 15-16 años (ICAOD=1.84). Los niveles de caries en los niños inmigrantes son significativamente altos. La media de sextantes con sangrado fue de 0.16, de 1.58 y de 1.10, mientras que con cálculo fue de 0.15, 0.76 y 0.88 respectivamente. Conclusión: Los niveles de caries tanto en dentición temporal como permanente a los 6 y 12 años se mantienen estables, mientras que a los 15-16 años siguen descendiendo. Los niños inmigrantes, con altos niveles de caries, constituyen un grupo poblacional con importantes necesidades de tratamiento y de aplicación de programas preventivos

Creencias y concepciones de los profesores: un estudio en un escenario virtual

Este trabajo pone en evidencia cambios en la concepción del profesor de matemáticas en servicio, referida particularmente a la noción de función lineal y de su proceso de enseñanza y aprendizaje, que se logran en un proceso de formación docente fundamentado en resultados teóricos y experimentales producto de la Matemática Educativa y organizado con base en las pautas instruccionales propias de la educación a distancia en línea. Es decir, no obviamos, ni trivializamos el escenario, por el contrario acentuamos las posibilidades de comunicación, interacción e interactividad que permite que este cambio de concepciones sea producto de la discusión, la reflexión y la producción personal y colectiva

Electrocatalysis on shape-controlled metal nanoparticles: Progress in surface cleaning methodologies

The use of shape-controlled metal nanoparticles has produced not only a clear enhancement in the electrocatalytic activity of different reactions of interest but also a better understanding of the effect of the surface structure on nanoscaled materials. However, it is well-accepted that a correct understanding of the correlations between shape/surface structure and electrochemical reactivity indispensably requires the use of clean surfaces. In this regard, and considering that most of the synthetic methodologies available in the literature for the preparation of these shaped metal nanoparticles employ capping agents, the development of effective surface cleaning methodologies able to remove such capping agents from the surface of the corresponding nanoparticles, becomes an extremely important prerequisite to subsequently evaluate their electrocatalytic properties for any reaction of interest. Consequently, in this contribution, we summarize the most relevant advances about surface cleaning procedures applied to different shaped metal nanoparticles for electrocatalytic purposes. It is worth mentioning that this work will only include contributions in which the surface cleanness of the samples is specifically evaluated using well-established electrochemical tools.This work has been financially supported by the MINECO of Spain through project CTQ2013-48280-C3-3-R. JSG acknowledges financial support from VITC (Vicerrectorado de Investigación y Transferencia de Conocimiento) of the University of Alicante

Demanda permanente e inversión privada en la teoría general: una investigación empírica

We empirically test some Keynes’ (and post Keynesians’) assertions relative to the multiplier-accelerator principle. By means of the nonlinear causality test proposed by Diks and Wolski (2016), we conclude that in the United States domestic private investment is driven by permanent demand. We explain that this result is consistent with Keynes’s principle of effective demand in the long run. We hope this paper helps consolidating the potential consensus among Keynesian, Kaleckian and Sraffian economists initiated by the work of Allain (2015)Analizamos empíricamente algunos postulados keynesianos (y post keynesianos) relativos a la interacción multiplicador-acelerador. Mediante el test de causalidad no lineal de Diks y Wolski (2016), sostenemos que en los Estados Unidos existe evidencia a favor de que la inversión privada doméstica es motorizada por la demanda permanente. Argumentamos que este resultado es consistente con el principio de la demanda efectiva en el largo plazo. Esperamos que este trabajo ayude a consolidar el potencial consenso entre economistas Keynesianos, Kaleckianos y Sraffianos que inició el trabajo de Allain (2015