822 research outputs found
Gamification in the process of cognitive stimulation in children with Down syndrome
This research studies the use of new information and communication technologies for the benefit of children with Down syndrome, it is about the design and programming of an application for mobile devices that stimulates playful interactions with the resource of gamification that takes advantage of the technological potential of video games in the educational field. Its interface was designed using Adobe Animate software with Action script programming language, designing two-dimensional animated graphics that encourage affective, cognitive and behavioral processes such as animals, their habitat and food; it also incorporates scenarios and sounds of easy grouping to encourage their academic activity in attention, visual retention and cognitive stimulation. The methodology used to design the first prototype was a survey of teachers, psychologists and language specialists of the Foundation for children with special abilities "San Miguel de Salcedo" FUNESAMI, who actively contributed in the development, structure, content and implementation of the application, which was evaluated with the active participation of 14 children with Down syndrome in average age of 6 to 12 years, The application was evaluated with the active participation of 14 children with Down syndrome with an average age of 6 to 12 years, finding remarkable improvements in the attention and retention that the child directs to the game, achieving an interaction that facilitates the teaching-learning process compared to the traditional method, thus contributing to the improvement of the quality of life and development of the child patient, thus complying with what is stated in the Constitution of Ecuador contributing to the good living.info:eu-repo/semantics/publishedVersio
Real Time Auralization Module for Electronic Travel Aid Devices for People with Visual Disability
This paper presents a software module for real-timeauralization that was used to recreate the acoustic perceptionproduced by a sound obstacle in virtual and real environments.This module fulfills the function of inserting, in any audio signal,a three-dimensional positioning effect that allows the listenerto determine the location of a sound source within the chosentest environment. This effect was achieved with a processingtechnique called segmented convolution and several functionscontained in a database of head related impulse responses(HRIRs). The module was tested in a real environment anda virtual one. In the real test environment, the user had astereoscopic camera that fulfilled the function of an obstacledetector, as well as a computer and headphones, in which themodule was installed and three-dimensional sound alerts weregenerated. In this way, the effects could be recorded, analyzed,discussed and finally validated
Ecos del 8-m: brecha salarial y libertad
Los agentessociales deben ilustrar a la opinión pública sobre la brecha salarial entre hombres y mujeres y ayudar a eliminar sus causa
El mundo tras la pandemia: el Estado
La pandemia sorprendió a casi todos los gobiernos y los enfrentó a un escenario inédito, para el que apenas estaban preparados. El ambiente era casi de guerra y favoreció el fortalecimiento del estado, circunstancia que los gobiernos aprovecharon.
Análisis del entorno social
El gran mito de la modernidad, el valor que adora el moderno y que suplanta al bien y a la verdad de los clásicos, es el progreso. alimentado por la ciencia y la tecnología, apunta a la instauración de una sociedad perfect
A distributed, predictive secondary control for voltage and frequency regulation, economic dispatch and imbalance sharing in isolated microgrids
Microgrids (MGs) are the cornerstone for a new model of electrical generation and distribution based on renewable resources. However, managing the operation of an MG is a challenging and complex task due to the characteristics of the various types of renewable sources and interactions between different types of generating equipment. In this context, some of the most pressing problems in MGs are associated with guaranteeing a cost-effective operation and the quality of the supply. Therefore, new and more reliable control strategies need to be developed for the management of microgrids. Distributed model predictive control (DMPC) is one of the best solutions for MGs as it can model complex systems and simultaneously address multiple objectives.
Traditionally MGs have been controlled via a three-level hierarchical structure, where each level operates at a different time scale. The primary control level is the fastest and aims to maintain the stability of the MG and ensures correct power sharing. The secondary control level restores the variables modified by the primary control level. The tertiary control level is the slowest and aims for economic dispatch (i.e., aiming for the lowest monetary cost of generated energy) of the MG and correct coordination with the main grid. However, isolated MGs are prone to fast changes in generation and demand whilst having a slow time response at the tertiary control level. The latest research suggests that this control should be performed on a time-scale comparable to that used at the secondary control level. In addition, as the power references sent by the tertiary control level tend to be updated with a slower sample time, the power limits of distributed generators (DGs) can be exceeded.
Therefore, this thesis focuses on the application of DMPC schemes for the secondary control level for ac MGs and hybrid ac/dc microgrids (H-MGs - composed of an ac sub-MG and a dc sub-MG connected through interlinking converters (ILCs)). The main characteristics of the proposed methodologies are the use of novel multi-objective cost functions and prediction models that correctly represent the main dynamics of the DGs and the ILCs (in the case of H-MGs) in the formulation. Three control strategies are proposed that fulfil the main task of the secondary control level (i.e., restoring frequency and voltage). These strategies are able to restore the frequency and voltage to nominal values or within secure bands. The first proposed strategy considers the economic dispatch of DGs in a balanced ac MG. The second strategy achieves the economic dispatch of ac DGs, dc DGs and manages the power transference of ILCs based on an economic criterion in H-MGs. The third strategy manages the sharing of phase imbalance in an unbalanced ac MG. All the proposed strategies include important operating constraints, e.g., power limits due to convertor ratings.
Extensive experimental, real-time simulation and simulation studies validate the proposed DMPC schemes for the most common operating scenarios in MGs, namely, load changes, robustness in the presence of changes in microgrid structure (i.e., disconnection and reconnection of DGs and ILCs (in H-MGs)), and communication link failures and communication delays. Finally, the controllers’ scalability has been investigated, and comparative studies have also been performed to highlight the advantages of the proposed schemes over other reported distributed schemes
A distributed, predictive secondary control for voltage and frequency regulation, economic dispatch and imbalance sharing in isolated microgrids
Microgrids (MGs) are the cornerstone for a new model of electrical generation and distribution based on renewable resources. However, managing the operation of an MG is a challenging and complex task due to the characteristics of the various types of renewable sources and interactions between different types of generating equipment. In this context, some of the most pressing problems in MGs are associated with guaranteeing a cost-effective operation and the quality of the supply. Therefore, new and more reliable control strategies need to be developed for the management of microgrids. Distributed model predictive control (DMPC) is one of the best solutions for MGs as it can model complex systems and simultaneously address multiple objectives.
Traditionally MGs have been controlled via a three-level hierarchical structure, where each level operates at a different time scale. The primary control level is the fastest and aims to maintain the stability of the MG and ensures correct power sharing. The secondary control level restores the variables modified by the primary control level. The tertiary control level is the slowest and aims for economic dispatch (i.e., aiming for the lowest monetary cost of generated energy) of the MG and correct coordination with the main grid. However, isolated MGs are prone to fast changes in generation and demand whilst having a slow time response at the tertiary control level. The latest research suggests that this control should be performed on a time-scale comparable to that used at the secondary control level. In addition, as the power references sent by the tertiary control level tend to be updated with a slower sample time, the power limits of distributed generators (DGs) can be exceeded.
Therefore, this thesis focuses on the application of DMPC schemes for the secondary control level for ac MGs and hybrid ac/dc microgrids (H-MGs - composed of an ac sub-MG and a dc sub-MG connected through interlinking converters (ILCs)). The main characteristics of the proposed methodologies are the use of novel multi-objective cost functions and prediction models that correctly represent the main dynamics of the DGs and the ILCs (in the case of H-MGs) in the formulation. Three control strategies are proposed that fulfil the main task of the secondary control level (i.e., restoring frequency and voltage). These strategies are able to restore the frequency and voltage to nominal values or within secure bands. The first proposed strategy considers the economic dispatch of DGs in a balanced ac MG. The second strategy achieves the economic dispatch of ac DGs, dc DGs and manages the power transference of ILCs based on an economic criterion in H-MGs. The third strategy manages the sharing of phase imbalance in an unbalanced ac MG. All the proposed strategies include important operating constraints, e.g., power limits due to convertor ratings.
Extensive experimental, real-time simulation and simulation studies validate the proposed DMPC schemes for the most common operating scenarios in MGs, namely, load changes, robustness in the presence of changes in microgrid structure (i.e., disconnection and reconnection of DGs and ILCs (in H-MGs)), and communication link failures and communication delays. Finally, the controllers’ scalability has been investigated, and comparative studies have also been performed to highlight the advantages of the proposed schemes over other reported distributed schemes
Influence of silvopastoral systems on the distribution of ticks in livestock farms in tropical dry forest
P?ginas 38-40.La corta de ?rboles en pasturas ha sido implementada en algunas regiones como una medida de control sanitario, ya que muchos productores creen dicen que los ectopar?sitos han sido encontrados bajo los ?rboles. El objetivo de este estudio fue generar informaci?n sobre la distribuci?n de garrapatas en el suelo de fincas ganaderas en el tr?pico seco. Este estudio fue realizado en cuatro fincas ganaderas de la provincia de Guanacaste, Costa Rica. La influencia de la cobertura de ?rboles individuales, en grupos, en cercas vivas y pasturas abiertas establecidas en pasturas de Brachiaria brizantha y Hyparrhenia rufa fueron evaluados. No se encontraron diferencias significativas (p = 0,77) en el n?mero de sitios con larvas de garrapatas larvas o en el total de n?mero de larvas en el suelo (p = 0,18) entre sistemas silvopastoriles y pasturas abiertas. Se encontr? una relaci?n significativa entre el n?mero total de larvas en el suelo y la presencia de ?rboles dispersos en la pastura (p=0,002), la humedad relativa (p=0,004) y la temperatura del aire (p=0,005). Se encontr? una relaci?n negativa entre el n?mero de sitios con larvas de garrapatas en el suelo y el ?rea de cobertura de dosel (p = 0,03). No se encontraron diferencias significativas entre la poblaci?n de larvas en el suelo bajo la cobertura de dosel entre sistemas silvopastoriles y pasturas abiertas, a pesar de encontrarse diferencias microclim?ticas (temperatura del aire y humedad relativa) entre estos sitios.ABSTRACT. The elimination of trees in pastures has been implemented in some regions as a control measurement due to lives-tock farmers think ectoparasites are found under tree canopy. The objective of the study was to generate information regarding the influence of tree cover in silvopastoral systems on tick distribution in soil of livestock (cattle) farms in the dry tropics. The influence of individual trees and trees in groups and live fences and open Brachiaria brizantha y Hyparrhenia rufa pastures was evaluated. No statistical differences (p=0.77) in the number of sites with tick larvae of or in the total number of larvae in soil (p = 0.18) between silvopastoral systems and open pastures. A significant relationship between the total number of tick larvae in the soil and presence of individual trees in pastures (p = 0.002), the relative humidity (p=0.004) and air?s temperature (p=0.005). A negative relationship was found between the number of sites with tick larvae in the soil and canopy tree area. No significant differences in larvae population in soil under tree cover between silvopastoral systems and open pastures, despite microclimatic conditions (air?s temperature and relative humidity) between both sites
Brazil's Engagement in International Development Cooperation: The State of the Debate
The international development cooperation architecture has changed dramatically over the last decade. The global context, characterised by a lingering financial crisis and the emergence of new powers, has brought South–South Development Cooperation (SSDC) to the core of international development debate. The growing influence of emerging countries, such as the BRICS (Brazil, Russia, India, China and South Africa), as development cooperation providers requires a deeper understanding of how and to what extent these countries are promoting sustainable and inclusive development by cooperating with partners in the global South. To be able to answer these questions, the national dynamics need to be unpacked by mapping institutions, ideas, and interests informing decision-making processes, and shaping, not only policy priorities, but also the effectiveness of development cooperation.
Brazil is in the spotlight and Brazilian cooperation, in all its different modalities (from technical, scientific and technological, educational, and humanitarian cooperation to contributions to international organisations, refugee support and protection, and peace operations), has risen to unprecedented levels in recent years. According to official data, Brazilian development cooperation increased from US900 million in 2010. In that period, the country’s technical cooperation disbursements grew almost fourfold and its humanitarian cooperation expanded from less than half a million dollars in 2005 to US$161 million in 2010. However, interviews and the current budget freeze on the Brazilian Cooperation Agency’s (ABC) activities indicate that the upward trend may have changed in the last three years.UK Department for International Developmen
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