Low-Cost Piezoelectric Sensors for Time Domain Load Monitoring of Metallic Structures During Operational and Maintenance Processes

The versatility of piezoelectric sensors in measurement techniques and their performance in applications has given rise to an increased interest in their use for structural and manufacturing component monitoring. They enable wireless and sensor network solutions to be developed in order to directly integrate the sensors into machines, fixtures and tools. Piezoelectric sensors increasingly compete with strain-gauges due to their wide operational temperature range, load and strain sensing accuracy, low power consumption and low cost. This research sets out the use of piezoelectric sensors for real-time monitoring of mechanical strength in metallic structures in the ongoing operational control of machinery components. The behaviour of aluminium and steel structures under flexural strength was studied using piezoelectric sensors. Variations in structural behaviour and geometry were measured, and the load and μstrains during operational conditions were quantified in the time domain at a specific frequency. The lead zirconium titanate (PZT) sensors were able to distinguish between material types and thicknesses. Moreover, this work covers frequency selection and optimisation from 20 Hz to 300 kHz. Significant differences in terms of optimal operating frequencies and sensitivity were found in both structures. The influence of the PZT voltage applied was assessed to reduce power consumption without signal loss, and calibration to μstrains and loads was performed.This research was funded by Basque Government, grant number KK-2019/00051-SMARTRESNAK and by the European Commission, grant number 869884- RECLAIM

Un caso práctico para la gestión del desarrollo agropecuario en municipios rurales de México

Una de las múltiples formas en que se atiende la pobreza en México es a través de la definición y diseño de estrategias de desarrollo enfocadas a mejorar las condiciones de vida de la población rural de escasos recursos económicos y déficit de bienestar social, actuando desde el municipio como articulador del desarrollo.Un texto detonante de preguntas y respuestas sobre la gestión del desarrollo rural y agropecuario desde la esfera municipal, en un esquema de gobernanza sugerente y efectivo, que retoma la experiencia de organizaciones civiles en los años recientes bajo el concepto y caso práctico de Municipio Ganador.Alternativas para el Desarrollo Rura

Horizontal collaboration in freight transport: concepts, benefits and environmental challenges

[EN] Since its appearance in the 1990s, horizontal collaboration (HC) practices have revealed themselves as catalyzers for optimizing the distribution of goods in freight transport logistics. After introducing the main concepts related to HC, this paper offers a literature review on the topic and provides a classification of best practices in HC. Then, the paper analyses the main benefits and optimization challenges associated with the use of HC at the strategic, tactical, and operational levels. Emerging trends such as the concept of ` green' or environmentally- friendly HC in freight transport logistics are also introduced. Finally, the paper discusses the need of using hybrid optimization methods, such as simheuristics and learnheuristics, in solving some of the previously identified challenges in real- life scenarios dominated by uncertainty and dynamic conditions.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness & FEDER (TRA2013-48180-C3-P, TRA2015-71883-REDT), The Erasmus+ program (2016-1-ES01-KA108-023465), the Ibero American Program of Science and Technology for Development (CYTED2014-515RT-0489), the CAN Foundation (CAN2014-3758, CAN2015-70473), and the Spanish Ministry of Education (FPU-14/00024).Serrano-Hernandez, A.; Juan, AA.; Faulin, J.; Perez-Bernabeu, E. (2017). Horizontal collaboration in freight transport: concepts, benefits and environmental challenges. SORT. Statistics and Operations Research Transactions. 41(2):393-414. https://doi.org/10.2436/20.8080.02.65S39341441

Auditory and Spatial Assessment in Inattentive Children Using Smart Devices and Gesture Interaction

We present an interactive game for assessing auditory and spatial memory. We compared the performance of children with and without inattention using the game and using a variety of classical tools for assessment of auditory and spatial memory. The children with inattention showed statistically worse performance in the game. There were no statistically significant differences between the two groups for the satisfaction and interaction outcomes. Therefore, our game could be a good tool for distinguishing performances of children with and without inattention

A virtual object-location task for children: Gender and videogame experience influence navigation; age impacts memory and completion time

The use of virtual reality-based tasks for studying memory has increased considerably. Most of the studies that have looked at child population factors that influence performance on such tasks have been focused on cognitive variables. However, little attention has been paid to the impact of non-cognitive skills. In the present paper, we tested 52 typically-developing children aged 5-12 years in a virtual object-location task. The task assessed their spatial short-term memory for the location of three objects in a virtual city. The virtual task environment was presented using a 3D application consisting of a 120" stereoscopic screen and a gamepad interface. Measures of learning and displacement indicators in the virtual environment, 3D perception, satisfaction, and usability were obtained. We assessed the children's videogame experience, their visuospatial span, their ability to build blocks, and emotional and behavioral outcomes. The results indicate that learning improved with age. Significant effects on the speed of navigation were found favoring boys and those more experienced with videogames. Visuospatial skills correlated mainly with ability to recall object positions, but the correlation was weak. Longer paths were related with higher scores of withdrawal behavior, attention problems, and a lower visuospatial span. Aggressiveness and experience with the device used for interaction were related with faster navigation. However, the correlations indicated only weak associations among these variables

Fourier Transforms for Generalized Fredholm Equations

In this chapter we take the conventional Fredholm integral equations as a guideline to define a broad class of equations we name generalized Fredholm equations with a larger scope of applications. We show first that these new kind of equations are really vector-integral equations with the same properties but with redefined and also enlarged elements in its structure replacing the old traditional concepts like in the case of the source or inhomogeneous term with the generalized source useful for describing the electromagnetic wave propagation. Then we can apply a Fourier transform to the new equations in order to obtain matrix equations to both types, inhomogeneous and homogeneous generalized Fredholm equations. Meanwhile, we discover new properties of the field we can describe with this new technology, that is, mean; we recognize that the old concept of nuclear resonances is present in the new equations and reinterpreted as the brake of the confinement of the electromagnetic field. It is important to say that some segments involving mathematical details of our present work were published somewhere by us, as part of independent researches with different specific goals, and we recall them as a tool to give a sound support of the Fourier transforms

APPLICATION FOR FUNCTIONALITY AND REGISTRATION IN THE CLOUD OF A MICROCONTROLLER DEVELOPMENT BOARD FOR IOT IN AWS

The use of the Amazon Web Services cloud enables new functionalities that are not possible with traditional solutions: low latency, local data processing and storage, and direct connectivity to other cloud services. Reimagining the way IoT connectivity services are presented by combining AWS cloud technology with mobile connectivity offers rapid prototyping to help connect devices natively over Wi-Fi. For this, the MQTT communication protocol is used to interact with the IoT device and exchange data, which allows controlling the basic functions of a sensor node. The installation is realized through a software development kit (SDK), which allows the creation of an application for Android devices. This solution gives the option to integrate together, improving the connectivity of the IoT system. The results enable board logging and network configuration, and can also be used to control the IoT device. The embedded firmware provides the required security functions

Actividad física en niños con síndrome de down estudio de caso.

La investigación se planteó con una propuesta metodológica de actividad física para dos sujetos en condición de síndrome de Down. este proyecto cuenta con la descripción del problema los objetivos planteados, la investigación de los temas a trabajar, las leyes en las cuales podemos basarnos, el diseño metodológico y la propuesta de actividades a realizar

Actividad física en niños con síndrome de down estudio de caso.

La investigación se planteó con una propuesta metodológica de actividad física para dos sujetos en condición de síndrome de Down. este proyecto cuenta con la descripción del problema los objetivos planteados, la investigación de los temas a trabajar, las leyes en las cuales podemos basarnos, el diseño metodológico y la propuesta de actividades a realizar