Comparison Between Reactive and Proactive Protocols of Wireless Sensor Networks: Railway Application

Railway is a critical application; hence, all systems that compose the railway infrastructure must meet two conditions: availability and safety. The availability ensures continuous operation of the system; on the other hand, safety is achieved when the device works properly regardless of the environmental or operating conditions. In addition, Wireless Sensor Networks (WSN) are used to perform tasks previously performed manually. However, it is necessary to analyse what protocol is appropriate for the railway industry, since availability and safety are the required attributes. In this work, a recently proposed routing protocol, the Multi-Parent Hierarchical (MPH), has been compared with a well-known protocol, the Ad-hoc On-Demand Distance Vector (AODV), in order to find the most suitable one for the railway applications. For this purpose, a simulator has been developed, which faithfully reifies the workings of a given protocol, considering a fixed, reconfigurable ad-hoc network given by the number and location of participants, and general network conditions.</p

Evaluation of the antimicrobial, antioxidant and physicochemical properties of Poly(Vinyl chloride) films containing quercetin and silver nanoparticles

This work provides details regarding the physicochemical, antimicrobial and antioxidant properties of poly(vinyl chloride) (PVC)-based films containing 0.4% quercetin and silver nanoparticles (AgNPs) at various concentrations levels. The incorporation of quercetin and AgNPs into the PVC matrix considerably affected the thermal, mechanical and optical properties of the films. Results obtained from the tensile stresgth test, demonstrated an improvement in the mechanical strength of the films after the incorporation of both quercetin and AgNPs. Moreover, an increase in AgNPs concentration increased the rigidity, as compared to control PVC film. Antimicrobial activity against food pathogens (Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes) was evaluated by an antimicrobial barrier test. Results showed that the PVC-based films with quercetin and AgNPs proved to be highly effective to inhibiting bacterial growth. Therefore, these results indicate promising evidence to possibly aid in the prevention of microbial dissemination in foods. Additionally, films incorporated with quercetin and AgNPs expressed an antioxidant capacity when evaluated via the DPPH method. Among all of the films evaluated, the PVC-based films containing 0.4% quercetin and 1% AgNPs were flexible, exhibiting excellent UV-light barrier properties and for use with fatty foods, with the intent of reducing lipid oxidation and preventing food pathogen dissemination.Fil: Braga, Lilian R.. Universidade do Brasília; BrasilFil: Perez, Leonardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Soazo, Marina del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Machado, Fabricio. Universidade do Brasília; Brasi

Evaluación de la degradación de la tierra usando la entropía de shannon sobre imágenes polarimétricas en desiertos costeros Patagónicos

En esta investigación se focalizó en la Entropía de Shannon (ES) para la caracterización de imágenes polarimétricas de apertura sintética. Este parámetro analiza la contribución de la información por pixeles individuales para toda la imagen en la evaluación de la degradación de la tierra en imágenes ALOS PALSAR. Escenas de polarización dual y cuádruple fueron adquiridas bajo el proyecto SAOCOM (Satélite Argentino de Observación con Microondas) en 2010 y 2011, del desierto costero noreste patagónico, Argentina. Los mapas fueron verificados con información de alta verosimilitud para la misma área de estudio. Los resultados muestran que la ES puede describir y precisar las características de las imágenes de manera obvia, de tal manera que representa un valor de referencia para la detección de la degradación de la tierra y la extracción de las características de los diferentes estados y transiciones.We focus on Shannon Entropy (SE) for the characterization of polarimetric Synthetic Aperture Radar (PolSAR) images. This approach analyzes the information contribution made by individual pixels to the whole image for assessment of land degradation in the information content of ALOS PALSAR images. Additionally, the performance of other polarization parameters, and polarization decomposition is illustrated and discussed. Dual-Pol and Quad-Pol scenes have been acquired under the SAOCOM (Satélite Argentino de Observación con Microondas, Spanish for Argentine Microwaves Observation Satellite) project in 2010 and 2011, from northeastern Patagonian coastal desert, Argentina. The accuracy of the SE map was assessed using a set of ground observations based on remotely sensed data that have higher accuracy. The results show that the SE can describe and determine the image features more obviously in the study area, so that it represents an important reference value for land degradation detection and land status characteristics extraction .Fil: del Valle, Hector Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; ArgentinaFil: Hardtke, Leonardo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; ArgentinaFil: Blanco, Paula Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagonico; ArgentinaFil: Sione, Walter Fabian. Universidad Autónoma de Entre Ríos. Fac de Ciencia y Tecnologia. Centro Regional de Geomatica; Argentina. Universidad Nacional de Luján; Argentin

Exploiting symmetries in skyrmionic micromagnetic simulations : cylindrical and radial meshes

Altres ajuts: Acord transformatiu CRUE-CSICMicromagnetic simulations are an essential tool in the theoretical study of magnetic skyrmions. When confined into nanometric samples, these structures can serve as bits of information among other possible applications. Accurate simulations are one of the major sources of theoretical results. In the case of confined skyrmions, it is known that the boundaries play a critical role in their stabilization. However, most of the micromagnetic simulations are done using a finite-difference method with quadrilateral meshes, that do not exactly fit the boundaries. The use of this mesh can introduce a significant numerical error that can completely change the results of the simulations. We present here two different finite-difference meshes to study skyrmions in confined disks, taking advantage of the symmetry of that geometry. A two-dimensional cylindrical mesh for non-symmetric scenarios but geometrically symmetric (boundary conditions) that reduces the propagation of the numerical error, and the particular case of a one dimensional mesh for axisymmetric scenarios where the computation time is hugely reduced

Comparison of Collaborative and Cooperative Schemes in Sensor Networks for Non-Invasive Monitoring of People at Home

This paper looks at wireless sensor networks (WSNs) in healthcare, where they can monitor patients remotely. WSNs are considered one of the most promising technologies due to their flexibility and autonomy in communication. However, routing protocols in WSNs must be energy-efficient, with a minimal quality of service, so as not to compromise patient care. The main objective of this work is to compare two work schemes in the routing protocol algorithm in WSNs (cooperative and collaborative) in a home environment for monitoring the conditions of the elderly. The study aims to optimize the performance of the algorithm and the ease of use for people while analyzing the impact of the sensor network on the analysis of vital signs daily using medical equipment. We found relationships between vital sign metrics that have a more significant impact in the presence of a monitoring system. Finally, we conduct a performance analysis of both schemes proposed for the home tracking application and study their usability from the user’s point of view

An Energy Model Using Sleeping Algorithms for Wireless Sensor Networks under Proactive and Reactive Protocols: A Performance Evaluation

The continuous evolution of the Internet of Things (IoT) makes it possible to connect everyday objects to networks in order to monitor physical and environmental conditions, which is made possible due to wireless sensor networks (WSN) that enable the transfer of data. However, it has also brought about many challenges that need to be addressed, such as excess energy consumption. Accordingly, this paper presents and analyzes wireless network energy models using five different communication protocols: Ad Hoc On-Demand Distance Vector (AODV), Multi-Parent Hierarchical (MPH), Dynamic Source Routing (DSR), Low Energy Adaptive Clustering Hierarchy (LEACH) and Zigbee Tree Routing (ZTR). First, a series of metrics are defined to establish a comparison and determine which protocol exhibits the best energy consumption performance. Then, simulations are performed and the results are compared with real scenarios. The energy analysis is conducted with three proposed sleeping algorithms: Modified Sleeping Crown (MSC), Timer Sleeping Algorithm (TSA), and Local Energy Information (LEI). Thereafter, the proposed algorithms are compared by virtue of two widely used wireless technologies, namely Zigbee and WiFi. Indeed, the results suggest that Zigbee has a better energy performance than WiFi, but less redundancy in the topology links, and this study favors the analysis with the simulation of protocols with different nature. The tested scenario is implemented into a university campus to show a real network running

Sweep frequency response analysis test as tool for distribution transformers management

Distribution transformers used in secondary substations are strongly affected during faults in low voltage grids. Transformers are expected to survive a number of short circuits without failure but, once any significant winding deformation or core damage is produced, the service life and the likelihood of surviving further short circuits is greatly reduced because of locally increased electromagnetic stresses. Given the need for diagnosing failures and quickly putting the unit back into service it is evident that a complete set of tests, as done in power transformers’ condition assessment, is not an option. The main objective of this paper is to present Sweep Frequency Response Analysis (SFRA) test as an alternative to assess the mechanical condition of distribution transformers. For this purpose, a special design of a distribution transformer was used to simulate some failure modes and improve interpretation criteria.Facultad de Ingenierí

La gestión académica en el diseño curricular de la práctica pedagógica investigativa en la Institución Educativa Normal Superior Montes de María /

La Gestión académica en el diseño curricular de la práctica pedagógica investigativa en la Institución Educativa Normal Superior Montes de María, es una experiencia de sistematización que partió de la reflexión y práctica de las estrategias de educación para la paz utilizadas en los últimos trece años en el contexto de la Normal Superior Montes de María, para transformar la violencia cultural heredada del conflicto armado que azotó la Región Montes de María en Colombia desde la práctica pedagógica investigativa; y pretende constituirse en un aporte sustancial para la construcción de una cultura de paz desde procesos educativos en otra instituciones educativas de la región y el país. Este trabajo se centró en sistematizar el proceso de gestión académica en el diseño curricular de las prácticas pedagógicas investigativas en la formación del Normalista Superior mediador de una cultura de paz, por tanto sólo se reconstruirán las experiencias que posibilitaron el diseño del microcurrículo de prácticas pedagógicas desde las vivencias de los participantes de la experiencia y desde las teorías de L. Stenhouse, Kemmis, M. Zabalza, A. De Alba, Abranham Magendzo, Angel Díaz Barriga, Gimeno Sacristán, G. Ianfrancesco, José Tuvilla, Paulo Freire, entre otros autores que han iluminado la comprensión epistemológica de la gestión académica, el diseño del currículo, la práctica pedagógica investigativa y la cultura de paz.Incluye referencias bibliográficas (páginas 184-194

Estadística de ensayos de recepción de aisladores elemento de cadena

Se presenta un análisis estadístico del desempeño de aisladores de porcelana de cadena, correspondientes a diferentes lotes, realizados de acuerdo a la norma IEC 60383-1. El análisis tiene en cuenta los ensayos en aisladores de porcelana realizados durante casi 40 años en el Laboratorio de Alta Tensión del Instituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos de la Facultad de Ingeniería de la Universidad Nacional de la Plata (IITREE). Se distinguen los ensayos con mayor frecuencia de falla y se analizan, en la medida de lo posible, las causas de las fallas.Comité de Estudio B2 - Líneas AéreasInstituto de Investigaciones Tecnológicas para Redes y Equipos Eléctricos (IITREE