Human-computer interaction based on hand gestures using RGB-D sensors

In this paper we present a new method for hand gesture recognition based on an RGB-D sensor. The proposed approach takes advantage of depth information to cope with the most common problems of traditional video-based hand segmentation methods: cluttered backgrounds and occlusions. The algorithm also uses colour and semantic information to accurately identify any number of hands present in the image. Ten different static hand gestures are recognised, including all different combinations of spread fingers. Additionally, movements of an open hand are followed and 6 dynamic gestures are identified. The main advantage of our approach is the freedom of the user’s hands to be at any position of the image without the need of wearing any specific clothing or additional devices. Besides, the whole method can be executed without any initial training or calibration. Experiments carried out with different users and in different environments prove the accuracy and robustness of the method which, additionally, can be run in real-time

Turbulent Advection of Reacting Substances

Abstract The turbulent advection of a reacting substance is considered. The existence of two different states, one smooth and the other filamental, is discussed. The transition between these states is characterized in terms of the competition of the stretching and folding mechanism of the turbulent field and the tendency of the scalar field to relax to the non-homogeneous steady state. Key words: Turbulent mixing, Synthetic flows, Stretching rate, Pattern formation PACS: 47.27. Qb, 47.70.Fw, 47.54.+r Mixing in fluids has attracted much interest in recent years and particular considerable progress has been made concerning chaotic advection We consider here the turbulent advection of a reacting scalar field C( r, t). The scalar field is assumed to be passive, i.e. it does not affect the turbulent velocity field and its dynamics to be stable, that is, in the absence of the advecting field the system relaxes to a non-homogeneous steady state C 0 ( r). The reaction-advection equation for the scalar field C( r, t) reads ∂C ∂t + v( r, t) · ∇C = α(C 0 ( r) − C)

Evaluación mediante simulación de las competencias clínicas de los alumnos del máster en Enfermería de Anestesia, Reanimación y Terapia del Dolor de la UB.

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Introduccion: EL MARTD es actualmente semipresencial con considerable contenido en prácticas clínicas que se desarrollan individualmente con tutores clínicos de varios centros asistenciales. La dispersión y posible variabilidad de esta organización debe garantizar el contenido y calidad del aprendizaje. En el curso 2013-14 planteamos evaluar los resultados de las prácticas con un doble objetivo: valorar las competencias de los alumnos y si nuestra organización conseguía los objetivos prácticos. El instrumento fue la observación de la actuación del alumno en un entorno simulado al final del periodo práctico. Metodologia: - Participaron los 60 alumnos matriculados, 30 evaluadores (15 enfermeras y 15 anestesiólogos) y 12 coordinadores de rotaciones y de estaciones. - Diseño de 6 estaciones con contenido relevante para la formación, ejecución en 10 min seguido de 15 min de “debriefing”, plantillas de evaluación de habilidades clínicas y no clínicas y criterios acordados por los evaluadores. Las estaciones fueron valoración preanestésica, bloqueo de plexo, anestesia general, preparación de perfusiones electrónicas de fármacos, depresión respiratoria y shock anafiláctico. - Se entrenó a los instructores sobre contenido y finalidad de la prueba, con 2 reuniones prácticas..

Does ohmic heating influence the flow field in thin-layer electrodeposition?

In thin-layer electrodeposition the dissipated electrical energy leads to a substantial heating of the ion solution. We measured the resulting temperature field by means of an infrared camera. The properties of the temperature field correspond closely with the development of the concentration field. In particular we find, that the thermal gradients at the electrodes act like a weak additional driving force to the convection rolls driven by concentration gradients.Comment: minor changes: correct estimation of concentration at the anode, added Journal-re

The transitional gap transient AT 2018hso: new insights into the luminous red nova phenomenon

Context. The absolute magnitudes of luminous red novae (LRNe) are intermediate between those of novae and supernovae (SNe), and show a relatively homogeneous spectro-photometric evolution. Although they were thought to derive from core instabilities in single stars, there is growing support for the idea that they are triggered by binary interaction that possibly ends with the merging of the two stars. Aims. AT 2018hso is a new transient showing transitional properties between those of LRNe and the class of intermediate-luminosity red transients (ILRTs) similar to SN 2008S. Through the detailed analysis of the observed parameters, our study supports that it actually belongs to the LRN class and was likely produced by the coalescence of two massive stars. Methods. We obtained ten months of optical and near-infrared photometric monitoring, and 11 epochs of low-resolution optical spectroscopy of AT 2018hso. We compared its observed properties with those of other ILRTs and LRNe. We also inspected the archival Hubble Space Telescope (HST) images obtained about 15 years ago to constrain the progenitor properties. Results. The light curves of AT 2018hso show a first sharp peak (reddening-corrected M-r = -13.93 mag), followed by a broader and shallower second peak that resembles a plateau in the optical bands. The spectra dramatically change with time. Early-time spectra show prominent Balmer emission lines and a weak [Ca II] doublet, which is usually observed in ILRTs. However, the strong decrease in the continuum temperature, the appearance of narrow metal absorption lines, the great change in the H alpha strength and profile, and the emergence of molecular bands support an LRN classification. The possible detection of a M-I similar to -8 mag source at the position of AT 2018hso in HST archive images is consistent with expectations for a pre-merger massive binary, similar to the precursor of the 2015 LRN in M101. Conclusions. We provide reasonable arguments to support an LRN classification for AT 2018hso. This study reveals growing heterogeneity in the observables of LRNe than has been thought previously, which is a challenge for distinguishing between LRNe and ILRTs. This suggests that the entire evolution of gap transients needs to be monitored to avoid misclassifications

Global firing induced by network disorder in ensembles of active rotators

We study the influence of repulsive interactions on an ensemble of coupled excitable rotators. We find that a moderate fraction of repulsive interactions can trigger global firing of the ensemble. The regime of global firing, however, is suppressed in sufficiently large systems if the network of repulsive interactions is fully random, due to self-averaging in its degree distribution. We thus introduce a model of partially random networks with a broad degree distribution, where self-averaging due to size growth is absent. In this case, the regime of global firing persists for large sizes. Our results extend previous work on the constructive effects of diversity in the collective dynamics of complex systems.Comment: 8 pages, 6 figure