A Robust Localization System for Inspection Robots in Sewer Networks †

Sewers represent a very important infrastructure of cities whose state should be monitored periodically. However, the length of such infrastructure prevents sensor networks from being applicable. In this paper, we present a mobile platform (SIAR) designed to inspect the sewer network. It is capable of sensing gas concentrations and detecting failures in the network such as cracks and holes in the floor and walls or zones were the water is not flowing. These alarms should be precisely geo-localized to allow the operators performing the required correcting measures. To this end, this paper presents a robust localization system for global pose estimation on sewers. It makes use of prior information of the sewer network, including its topology, the different cross sections traversed and the position of some elements such as manholes. The system is based on a Monte Carlo Localization system that fuses wheel and RGB-D odometry for the prediction stage. The update step takes into account the sewer network topology for discarding wrong hypotheses. Additionally, the localization is further refined with novel updating steps proposed in this paper which are activated whenever a discrete element in the sewer network is detected or the relative orientation of the robot over the sewer gallery could be estimated. Each part of the system has been validated with real data obtained from the sewers of Barcelona. The whole system is able to obtain median localization errors in the order of one meter in all cases. Finally, the paper also includes comparisons with state-of-the-art Simultaneous Localization and Mapping (SLAM) systems that demonstrate the convenience of the approach.Unión Europea ECHORD ++ 601116Ministerio de Ciencia, Innovación y Universidades de España RTI2018-100847-B-C2

Observation of cone and rod photoreceptors in normal subjects and patients using a new generation adaptive optics scanning laser ophthalmoscope.

We demonstrate the capability of a new generation adaptive optics scanning laser ophthalmoscope (AOSLO) to resolve cones and rods in normal subjects, and confirm our findings by comparing cone and rod spacing with published histology measurements. Cone and rod spacing measurements are also performed on AOSLO images from two different diseased eyes, one affected by achromatopsia and the other by acute zonal occult outer retinopathy (AZOOR). The potential of AOSLO technology in the study of these and other retinal diseases is illustrated

E-learning y mercado de trabajo: Análisis de primas salariales

El vínculo entre las TCI y la demanda de personal altamente calificado se debe a que la introducción de las tecnologías digitales altera los requisitos de calificación de los puestos de trabajo de tres formas principales (Spitz, 2003): 1) el capital de las TIC sustituye actividades manuales y cognitivas repetitivas, 2) el capital de las TIC complementa las actividades analíticas e interactivas, y 3) el capital de las TIC aumenta los requisitos en cuanto a destrezas informáticas. En este marco, hemos analizado los determinantes de la productividad laboral de personas que han seguido programas de educación superior por Internet para comprobar de qué forma los requisitos de capacidades ocupacionales y el grado de aplicación de las TIC por la industria se corresponden con las capacidades de las personas que han seguido cursos por Internet. Para llevar a cabo este análisis, hemos asumido que existe una relación implícita entre la educación y la capacidad (Griliches y Mason, 1972) reconociendo que las personas que han seguido cursos por Internet pueden adquirir habilidades específicas, como destrezas informáticas y habilidades relacionadas con el uso de las TIC. Para el análisis empírico, hemos usado una base de datos de estudiantes diplomados por la Universitat Oberta de Catalunya (UOC). Los resultados de nuestro modelo basado en ecuaciones de tipo minceriano muestran tres hechos importantes: 1) la educación no es una variable significativa para explicar las diferencias salariales; 2) la experiencia, entendida como productividad previa y elusión de pérdidas de producción, es la variable más importante para explicar las mejoras salariales; y 3) las destrezas de uso de las TIC tienen un efecto positivo y significativo en los rangos salariales

STED imaging performance estimation by means of Fourier transform analysis

Due to relatively high powers used in STED, biological samples may be affected by the illumination in the process of image acquisition. Similarly, the performance of the system may be limited by the sample itself. Optimization of the STED parameters taking into account the sample itself is therefore a complex task as there is no clear methodology that can determine the image improvement in an objective and quantitative manner. In this work, a method based on Fourier transform formalism is presented to analyze the performance of a STED system. The spatial frequency distribution of pairs of confocal and STED images are compared to obtain an objective parameter, the Azimuth Averaged Spectral Content Spread (AASCS), that is related to the performance of the system in which the sample is also considered. The method has been first tested on samples of beads, and then applied to cell samples labeled with multiple fluorescent dyes. The results show that a single parameter, the AASCS, can be used to determine the optimal settings for STED image acquisition in an objective way, only by using the information provided by the images from the sample themselves. The AASCS also helps minimize the depletion power, for better preservation of the samples.Peer ReviewedPostprint (published version

Confidence-Based Learning in Investment Analysis

The aim of this study is to determine the effectiveness of using multiple choice tests in subjects related to the administration and business management. To this end we used a multiple-choice test with specific questions to verify the extent of knowledge gained and the confidence and trust in the answers. The tests were performed in a group of 200 students at the bachelor's degree in Business Administration and Management. The analysis made have been implemented in one subject of the scope of investment analysis and measured the level of knowledge gained and the degree of trust and security in the responses at two different times of the course. The measurements have been taken into account different levels of difficulty in the questions asked and the time spent by students to complete the test. The results confirm that students are generally able to obtain more knowledge along the way and get increases in the degree of trust and confidence in the answers. It is confirmed as the difficulty level of the questions set a priori by the heads of the subjects are related to levels of security and confidence in the answers. It is estimated that the improvement in the skills learned is viewed favourably by businesses and are especially important for job placement of students

Weighted Contrastive Divergence

Learning algorithms for energy based Boltzmann architectures that rely on gradient descent are in general computationally prohibitive, typically due to the exponential number of terms involved in computing the partition function. In this way one has to resort to approximation schemes for the evaluation of the gradient. This is the case of Restricted Boltzmann Machines (RBM) and its learning algorithm Contrastive Divergence (CD). It is well-known that CD has a number of shortcomings, and its approximation to the gradient has several drawbacks. Overcoming these defects has been the basis of much research and new algorithms have been devised, such as persistent CD. In this manuscript we propose a new algorithm that we call Weighted CD (WCD), built from small modifications of the negative phase in standard CD. However small these modifications may be, experimental work reported in this paper suggest that WCD provides a significant improvement over standard CD and persistent CD at a small additional computational cost

John's ellipsoid and the integral ratio of a log-concave function

We extend the notion of John’s ellipsoid to the setting of integrable log-concave functions. This will allow us to define the integral ratio of a log-concave function, which will extend the notion of volume ratio, and we will find the log-concave function maximizing the integral ratio. A reverse functional affine isoperimetric inequality will be given, written in terms of this integral ratio. This can be viewed as a stability version of the functional affine isoperimetric inequality.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalConsejería de Industria, Turismo, Empresa e Innovación (Comunidad Autónoma de la Región de Murcia)Coordenação de aperfeiçoamento de pessoal de nivel superiorInstituto Nacional de Matemática Pura e Aplicad

Un marco teórico para la economía del e-learning

La economía del e-learning se identificó como una prioridad clave en el taller de asesoría de campus virtuales celebrado en Bruselas el 23 de noviembre de 2004. Con esta idea, el proyecto eLene-EE (Economía del e-learning) ha tratado de ampliar el conocimiento relativo a los incentivos para crear campus virtuales e iniciar métodos de enseñanza en la educación basada en las TIC y sus efectos, asegurando que esto se lleve a cabo eficazmente mientras refleja las diferentes situaciones de las universidades asociadas. Este número especial de RUSC sobre la economía del e-learning muestra el marco teórico que hemos definido y algunos de los resultados que hemos obtenido en el proyecto eLene-EE, que ha sido financiado por la Comisión Europea. Nuestros resultados tienen unas implicaciones políticas claras y ayudarán a los diseñadores, estudiantes, financieros y gestores de e-learning a crear, adaptar y mejorar sus iniciativas. El proyecto se divide en cinco paquetes de trabajo de investigación y desarrollo integrados con participantes de universidades del consorcio eLene (universidades de Suecia, Francia, España, Italia y Polonia)

Applying results from clinical trials: tranexamic acid in trauma patients.

This paper considers how results from clinical trials should be applied in the care of patients, using the results of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial of tranexamic acid in bleeding trauma patients as a case study. We explain why an understanding of the mechanisms of action of the trial treatment, and insight into the factors that might be relevant to this mechanism, is critical in order to properly apply (generalise) trial results and why it is not necessary that the trial population is representative of the population in which the medicine will be used. We explain why cause (mechanism)-specific mortality is more generalizable than all-cause mortality and why the risk ratio is the generalizable measure of the effect of the treatment. Overall, we argue that a biological insight into how the treatment works is more relevant when applying research results to patient care than the application of statistical reasoning