In this paper, we propose an energy-aware routing algorithm and a control overhead reduction technique for prolonging the network lifetime of software-defined multihop wireless sensor networks (SDWSNs). This is an effort to optimize the energy consumption of WSNs that provide services to the Industrial Internet of Things (IIoT). A centralized controller grants a global view of the sensor network by introducing extra control overhead in the network, but this leads to extra energy costs. However, our new algorithm takes advantage of this global view and balances the network energy by selecting paths with the highest remaining energy level among multiple paths for each sensor node. We also identify key functions draining energy from the SDWSN and minimize their impact by implementing a data packet aggregation function, and minimizing the control overhead by keeping track of the sensor nodes' routing tables using a simple checksum function. We show that the proposed approach prolongs the network lifetime of the WSN by 6.5% on average compared to the standard shortest-path algorithm, and that the control overhead is reduced by approximately 12% while still maintaining a very high packet delivery ratio.

This paper presents the results of an evaluation of a propagation model based on ray-tracing techniques using a game engine and Graphics Processing Unit (GPU) in outdoor scenarios, as a gap-filler for a Digital Video Broadcasting Handheld (DVB-H) service. This model involves complete identification of the parameters of wave propagation, multipath components between the transmitter and the receiver as attenuation, time delay of arrival (TDA), full polarimetric transmission matrix, direction of arrival DoA and the direction of departure DoD. In the paper, we present the results of the simulation and compare them with measurements, obtaining a satisfactory fit.Index Terms-game engine, ray tracing, digital video broadcasting, wave propagation.

RESUMENEn los años noventa surgieron metodologías de desarrollo de software ligeras -luego llamadas ágiles-dirigidas a reducir la probabilidad de fracaso por subestimación de costos, tiempos y funcionalidades en los proyectos de desarrollo de software. Se gestaron como alternativa a las metodologías tradicionales, específicamente para reducir la carga burocrática propia ellas, en proyectos de pequeña y mediana escala. A diferencia de las tradicionales, las metodologías ágiles son adaptativas -no predictivas-, y están orientadas a las personas -no a los procesos-. Este documento hace una revisión de publicaciones sobre las metodologías ágiles, sus principios y fundamentos; establece criterios para definir la relevancia de las metodologías ágiles; define y explica con detalle las más relevantes (i.e., Scrum y XP); y presenta las características de otras cuatro destacadas (i.e., DSDM, Crystal, ASD y FDD).Palabras clave: Scrum, XP, Método de desarrollo de sistemas dinámicos, Crystal, Desarrollo adaptativo de software, Desarrollo orientado a funcionalidades, Metodologías ágiles. ABSTRACTIn the nineties appeared lightweight software development methodologies -then called agile -that aimed to reduce the probability of failure due to underestimation of cost, time and functionality in software development projects. Agile methodologies were developed as an alternative to traditional methodologies specifically to reduce the bureaucratic burden in projects of small and medium scale. Unlike traditional methodologies, agile methodologies are adaptive and oriented to people. This document describes the agile methodologies, its principles and fundamentals, establishes a criteria for defining the relevance of the agile methodologies, defines and explains in detail the most relevant (i.e., Scrum and XP) and presents other prominent ones(i.e., DSDM, Crystal, ASD and FDD).Keywords: Scrum, XP, Dynamic system development method, Crystal, Adaptative software development, Feature-Driven Development, Agile methodologies. INTRODUCCIÓNEn la década de los noventa surgieron metodologías de desarrollo de software ligeras, más adelante nombradas como metodologías ágiles, que buscaban reducir la probabilidad de fracaso por subestimación de costos, tiempos y funcionalidades en los proyectos de desarrollo de software. Estas metodologías nacieron como reacción a las metodologías existentes con el propósito de disminuir la burocracia que implica la aplicación de las metodologías tradicionales en los proyectos de pequeña y mediana escala.Las metodologías tradicionales buscan imponer disciplina al proceso de desarrollo de software y de esa forma volverlo predecible y eficiente. Para conseguirlo se soportan en un proceso detallado con énfasis en planeación [1] propio de otras ingenierías. El principal problema de este enfoque es que hay muchas actividades que hacer para seguir la metodología y esto retrasa la etapa de desarrollo. Las metodologías ágiles tienen dos diferencias fundamentales con las metodologías tradicionales; la primera es que los mét...

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Background. Gait alterations are hallmarks for the diagnosis and follow-up of patients with Parkinson’s disease (PD). In normal conditions, age could affect gait dynamics. Although it is known that objective assessment of gait is a valuable tool for diagnosis and follow-up of patients with PD, only few studies evaluate the effect of aging on the gait pattern of patients with PD. Objective. The purpose of this study was to assess differences in gait dynamics between PD patients and healthy subjects and to investigate the effects of aging on these differences using a low-cost RGB-D depth-sensing camera. Methods. 30 PD patients and 30 age-matched controls were recruited. Descriptive analysis was used for clinical variables, and Spearman’s rank correlation was used to correlate age and gait variables. The sample was distributed in age groups; then, Mann–Whitney U test was used for comparison of gait variables between groups. Results. PD patients exhibited prolonged swing (p=0.002) and stance times (p<0.001) and lower speed values (p<0.001) compared to controls. This was consistent in all age groups, except for the one between 76 and 88 years old, in which the controls were slower and had longer swing and stance times. These results were statically significant for the group from 60 to 66 years. Conclusion. Gait speed, swing, and stance times are useful for differentiating PD patients from controls. Quantitative gait parameters measured by an RGB-D camera can complement clinical assessment of PD patients. The analysis of these spatiotemporal variables should consider the age of the subject.

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