ABSTRACT: The study of genotypic relationships between drought tolerance indices and agronomic traits of interest in wheat breeding is useful for designing selection strategies. The objective of this research was to investigate the cause-and-effect relationships between agronomic traits and drought tolerance indices through the analysis of canonical correlations. Two trials (control and stress) were conducted in winter 2020 in Viçosa, MG, Brazil. The traits evaluated were: (days for heading, plant height, mass and number of grains per spike, mass of one hundred grains, and grain yield). Grain yield data from the control and stress conditions were used to construct five drought tolerance indices. The data were subjected to mixed model analysis for estimation of genetic parameters and prediction of genotypic values (REML/BLUP), and then the genotypic values were used to calculate the correlation coefficients between the traits. Two groups of traits were established for the study of canonical correlations, the first group consisting of agronomic traits and the second by drought tolerance indices. There was a significant genotype effect for all evaluated traits. The canonical pairs were significant, which indicated the existence of dependence between the groups. Days to heading trait can be used in the indirect selection of wheat genotypes for drought tolerance. ABSTRACT strategies causeandeffect cause correlations 202 Viçosa MG Brazil days height spike yield. . yield) REML/BLUP, REMLBLUP REML/BLUP , REML BLUP (REML/BLUP) 20 (REML/BLUP 2

RESUMO: O estudo das relações genotípicas entre índices de tolerância à seca e caracteres agronômicos de interesse no melhoramento de trigo é útil para traçar estratégias de seleção. Objetivou-se com este trabalho investigar as relações de causa e efeito entre características agronômicas e índices de tolerância à seca via análise de correlações canônicas. Dois ensaios (controle e estresse) foram conduzidos no inverno de 2020 em Viçosa, MG, Brasil. Foram avaliados os caracteres (dias para o espigamento, altura da planta, massa e número de grãos por espiga, massa de cem grãos e rendimento de grãos). Os dados de produtividade dos ensaios de controle e estresse foram utilizados para construir cinco índices de tolerância à seca. Os dados foram submetidos à análise de modelos mistos para estimação dos parâmetros genéticos e predição dos valores genotípicos (REML/BLUP), em seguida, os valores genotípicos foram utilizados para calcular os coeficientes de correlação entre os caracteres. Dois grupos de caracteres foram estabelecidos para o estudo das correlações canônicas, sendo o primeiro grupo constituído pelas variáveis agronômicas e o segundo pelos índices de tolerância à seca. Houve efeito significativo de genótipo para todas as características avaliadas. Os pares canônicos foram significativos, o que indicou a existência de dependência entre os grupos. O caráter dias para o espigamento pode ser utilizado na seleção indireta de genótipos de trigo para tolerância à seca. RESUMO Objetivouse Objetivou se canônicas 202 Viçosa MG Brasil planta espiga grãos. . grãos) REML/BLUP, REMLBLUP REML/BLUP , REML BLUP (REML/BLUP) seguida avaliadas significativos 20 (REML/BLUP 2

ABSTRACT The estimation of evapotranspiration (ET) and crop water requirements are crucial for the proper management and allocation of water resources in terms of quantity, quality, and timeliness. Therefore, remote sensing estimation of ET using the SEBAL algorithm (Surface Energy Balance Algorithm for Land) can provide spatio-temporal, non-punctual data, unlike traditional calculations relying on the nearest meteorological station. This research analyzed ET using SEBAL, based on ten Landsat 8 satellite images processed with a program developed in the Model Builder of ArcGis® version 10.2. The analysis was conducted during the vegetative period of starchy corn from May to October 2016. Validation of the results happened with a drainage lysimeter installed in a monitoring plot. Additionally, the statistical indices - such as percentage relative error (PRE) (0,09), root mean square error (RMSE) (0,30), R2 (0,92), and Nash-Sutcliffe efficiency (NASH) (0,91) - indicated a good correlation of ET for starchy corn in the central highlands of Peru. The ET identified at ten monitoring points ranged from 1,05 to 7,79 mm d-1. (ET quantity quality timeliness Therefore Surface Land spatiotemporal, spatiotemporal spatio temporal, temporal spatio-temporal nonpunctual non punctual data station ArcGis 102 10 2 10.2 2016 plot Additionally PRE (PRE 0,09, 009 0,09 , 0 09 (0,09) RMSE (RMSE 0,30, 030 0,30 30 (0,30) R 0,92, 092 0,92 92 (0,92) NashSutcliffe Nash Sutcliffe NASH (NASH 0,91 091 91 (0,91 Peru 105 1 05 1,0 779 7 79 7,7 d1. d1 d 1. d-1 10. 201 00 0,0 (0,09 03 0,3 3 (0,30 0,9 9 (0,92 (0,9 1, 77 7, d- 20 0, (0,0 (0,3 (0, (0 (

This study offers a comprehensive analysis of how governance capacities in developing countries respond to the challenges that COVID-19 posed. We established a theoretical framework to delve into the multifaceted nature of governance capacities, exploring two distinct aspects of governance: the Weberian one, which focuses on material and organizational capacities, and the Tocquevillian one, which focuses on coordination and associational capacities. We examined these four governance dimensions to illustrate how these distinct skills influence the effectiveness of governance. Our analysis quantifies the impact of the COVID-19 pandemic using such metrics as confirmed cases and deaths. We employ standard and dynamic panel data methodologies to mitigate potential omitted variable bias. Our research findings indicate that countries with robust governance capacities, as assessed by the Bertelsmann Stiftung's Transformation Governance Index, are better equipped to respond effectively to pandemic crises. By applying several models and rigorous robustness tests, we demonstrate efficient resource utilization, the ability to guide and prioritize decision-making within the government, and commitment to cooperation and coordination with other nations and international organizations are the primary drivers of improved outcomes. Our findings remain robust even when controlling for relevant variables and employing estimation techniques that account for potential biases arising from unobservable confounding factors. COVID19 COVID 19 COVID-1 posed one deaths bias Stiftungs Stiftung s Index crises tests utilization decisionmaking decision making government outcomes factors COVID1 1 COVID-

RESUMO Vários estudos têm vinculado diferentes outcomes organizacionais como antecedentes às capacidades dinâmicas, sendo que se destacam o empreendedorismo, o dinamismo ambiental, os recursos, a gestão do conhecimento, a aprendizagem organizacional e o planejamento estratégico. O presente estudo tem por objetivo avaliar de forma completa, considerando todas as dimensões conceituais, como se relacionam o modelo das alavancas de controle estratégico e as capacidades dinâmicas, considerando o perfil dos empregados da ITAIPU Binacional. Os dados foram coletados por meio de um survey e as hipóteses avaliadas com o auxílio da modelagem de equações estruturais, empregando-se o método de estimação por mínimos quadrados parciais. Os resultados obtidos validaram a hipótese central de que as alavancas de controle influenciam positivamente a presença das capacidades dinâmicas, além de uma das hipóteses complementares de que o sistema interativo influencia positivamente a presença da capacidade de sentir as oportunidades. As alavancas de controle estratégico podem ser tratadas agora pelas organizações como possíveis fontes de capacidades dinâmicas. dinâmicas empreendedorismo ambiental recursos conhecimento completa conceituais Binacional estruturais empregandose empregando parciais oportunidades

ABSTRACT Several studies have thus far linked diverse organizational outcomes as antecedents to dynamic capabilities, with an emphasis on entrepreneurship, environmental dynamism, resources, knowledge management, organizational learning, and strategic planning. This study aims to fully assess how the model of strategic levers of control and dynamic capabilities framework are related, considering all conceptual dimensions and the profile of ITAIPU Binacional employees. The data was collected through a survey, and the hypotheses evaluated with the assistance of structural equation modelling, using the partial least squares estimation method. The findings validated the central hypothesis, that the levers of control do positively influence the presence of the dynamic capabilities, in addition to one other complementary hypothesis- that the interactive system also positively influences the ability to sense opportunities. The strategic levers of control can now be treated by organizations as possible sources of dynamic capabilities. entrepreneurship dynamism resources management learning planning related employees survey modelling method hypothesis opportunities

RESUMO Na agricultura irrigada, é comum a aplicação de água no solo cultivado sem critério, resultando em uso ineficiente ou não otimizado da água. Em muitos casos, a relação solo-água-planta, bem como as potencialidades e limitações dos sistemas de irrigação são ignoradas. A agricultura irrigada sustentável requer o desenvolvimento de um sistema de monitoramento da umidade do solo que evite a perda de água e melhore a eficiência do uso. O objetivo deste estudo foi desenvolver e avaliar a eficiência de um sistema inteligente de monitoramento da umidade do solo. O sistema é composto por duas estações: a primeira coleta os dados sobre parâmetros de umidade aparente do solo usando sensores, enquanto a segunda transmite esses dados para uma estação de processamento central. O sistema determina precisamente os valores atuais de umidade do solo, permitindo estimar o volume de água de irrigação necessário para atender à demanda hídrica da cultura com base na capacidade de campo. Os resultados da curva de calibração dos sensores indicam que o sistema pode medir com precisão a umidade do solo atual, auxiliando no manejo da irrigação. Para áreas irrigadas em condições de solo não saturado, recomenda-se o uso de tensiômetros devido à sua maior confiabilidade entre a capacidade de campo e o ponto de murcha permanente, garantindo práticas de irrigação mais precisas. critério casos soloáguaplanta, soloáguaplanta planta, planta solo-água-planta ignoradas estações central atual saturado recomendase recomenda se permanente precisas

ABSTRACT Water application to cultivated soil is often done without careful consideration in irrigated agriculture, leading to inefficient or suboptimal water usage. In many instances, the intricate relationship between soil, water, and plants, as well as the potential and limitations of irrigation systems, is overlooked. Sustainable irrigated agriculture necessitates the development of a soil moisture monitoring system that curtails water loss and enhances overall efficiency. This study aimed to develop and assess the efficiency of an intelligent system for monitoring soil moisture. The system comprises two stations: the first collects data on apparent soil moisture parameters using sensors, while the second transmits this data to a central processing station. The system precisely determines current soil moisture values, enabling estimation of the required irrigation water volume to meet the crop’s water demand based on field capacity. Results from the calibration curve of the sensors indicate that the system can measure current soil moisture precisely, aiding in irrigation management. For irrigated areas under unsaturated soil conditions, it is recommended to use tensiometers due to their higher reliability between field capacity and permanent wilting point, ensuring more accurate irrigation practices. usage instances plants systems overlooked stations station values crops crop s management conditions point practices

Resumen Objetivo: cuantificar la incertidumbre asociada con la estimación del valor actual del ciclo económico. Metodología: se emplea el filtro de Baxter y King en una serie de tiempo ampliada con proyecciones, asumiendo caminata aleatoria, y se construyen intervalos de confianza para el ciclo de manera analítica y con bootstrap. Limitaciones: la calidad de los intervalos de confianza se deteriora en presencia de cambio estructural en la serie de tiempo. Originalidad: la originalidad subyace en proponer una metodología para determinar la fase actual del ciclo económico de manera conjunta con una cuantificación de la incertidumbre respecto a tal medición. Conclusión: para Costa Rica, el método propuesto conduce a estimaciones del ciclo económico menos sensibles a nuevos datos que lo obtenido con el filtro de Hodrick y Prescott, y simulaciones muestran que los intervalos de confianza propuestos proveen la confianza nominal especificada.

Abstract Objetive: To quantify the uncertainty associated to the estimation of the current value of the business cycle. Methodology: The Baxter and King filter is applied to an time series expanded with forecasts, assuming a random walk, and confidence intervals are build for the cyclical component both analytically and using bootstrap. Limitations: The quality of the confidence 1 intervals deteriorates when there is a structural break in the time series. Originality: The original contribution of this article is a proposed methodology to jointly determined the current phase of the business cycle and the uncertainty associated with such measurement. Conclusions: For Costa Rica, the proposed method provides estimations of the business cycle that are less sensitive to new data points than the Hodrick and Prescott filter, and simulations show that the proposed confidence intervals provide the specified nominal confidence.

Abstract Introduction. Climate change adaptation measures require informed decision-making. However, small-scale agriculture shows low rates of technology adoption due to cost and lack of connectivity. Objective. To evaluate three low-cost prototypes of small-scale agriculture devices for soil moisture measurement in different soil textures, as well as to determine the respective calibration equations, and the effects of electrical conductivity and temperature on moisture measurement. Materials and methods. Three measurement and recording prototypes for soil moisture were evaluated in soils with variations in clay/sand content and electrical conductivity in productive plots at Zamorano University in Honduras and a demonstration farm in Popayán, Colombia during the first quarter of 2022. Commercial sensors were used as a reference to compare the performance of the prototypes through regression analysis of hourly sensor readings over 90 days. Electrical conductivity (dS/m) and temperature variables were collected to determine their influence on moisture reading accuracy. Results. The soil moisture measurement devices showed better performance in soils with lower sand content. The measurement from the devices overestimated moisture readings by 0.19 to 0.52 percentage points for each additional degree of soil temperature. Additionally, for each additional dS/m of electrical conductivity, the reading needed adjustment by 8 to 55 percentage points. Conclusions. Prototype A was the most accurate device, while prototype B was the most precise compared to commercial sensors. Soil moisture devices performed best in soils with lower sand content. The three models evaluated performed best in loam soil with a medium clay content.

Resumen Introducción. Las medidas de adaptación al cambio climático requieren de la toma de decisiones informadas. Sin embargo, la agricultura de pequeña escala muestra bajas tasas de adopción de tecnologías por su costo y falta de conectividad. Objetivo. Evaluar tres prototipos de dispositivos para agricultura de pequeña escala y de bajo costo para medir humedad de suelo en diferentes texturas, así como determinar las respectivas ecuaciones de calibración y los efectos de conductividad eléctrica y temperatura en la medida de humedad. Materiales y métodos. Se evaluaron tres prototipos de dispositivos de medición y registro de humedad de suelo, en suelos con diferencial en contenido de arcilla/arena y conductividad eléctrica en parcelas productivas de la Universidad Zamorano, en Honduras; y Finca demostrativa en Popayán, Colombia, durante el primer trimestre del 2022. Se tomaron como referencia sensores comerciales para la comparación del desempeño de los prototipos, mediante análisis de regresión de las lecturas por hora de los sensores durante 90 días. Se recolectaron las variables de conductividad eléctrica (dS/m) y temperatura para determinar la influencia en la precisión de la lectura de humedad. Resultados. Los dispositivos de medición y registro de humedad presentaron un mejor desempeño en suelos con menor contenido de arena. La medición de los dispositivos sobrestimó entre 0,19 y 0,52 puntos porcentuales la lectura de humedad por cada grado adicional de temperatura del suelo, y que por cada dS/m adicional de conductividad eléctrica la lectura se debe ajustar entre 8 y 55 puntos porcentuales. Conclusiones. El prototipo A fue el dispositivo más exacto, mientras que el prototipo B fue el más preciso, con respecto a los sensores comerciales. Los dispositivos de humedad presentaron un mejor desempeño en suelos con menor contenido de arena. Los tres modelos evaluados obtuvieron el mejor desempeño en suelo franco con contenido medio de arcilla.

Summary: The fraction of vegetation cover (FVC) and the Leaf Area Index (LAI) are biophysical variables closely related to the evapotranspiration rate of crops and their biomass production. Despite their importance, they are usually not measured directly due to their time-consuming and costly nature; however, they can be estimated on a large scale and near-real-time using spectral information captured in satellite images, although this requires prior validation at the field level. Simple linear regression models were developed and validated using 13 vegetation indices (VI) related to LAI and FCV in alfalfa (Medicago sativa). Three spectral information sources were used: (i) reflectance to derive the VI; (ii) digital photographs processed with the Canopeo application to estimate FVC; and (iii) direct LAI measurements using a ceptometer. Six field samples were taken between March and June, 2020 in four alfalfa plots located in Palmar de Bravo, Puebla, Mexico. To evaluate each VI, the determination coefficient (R2) and the root mean square error (RMSE) were used. We found that the most suitable VI for estimating FVC was the VIgreen (Green Vegetation Index, R2 =0.987 and RMSE = 0.093). For the LAI, the VI that performed best was the NDVI (Normalized Difference Vegetation Index, R2 = 0.935 and RMSE = 0.746). The results showed the suitability and practical utility of spectral information for estimating biophysical variables in alfalfa cultivation and their monitoring.

Resumen: La fracción de cobertura vegetal (FCV) y el índice de área foliar (IAF) son variables biofísicas relacionadas estrechamente con la tasa de evapotranspiración de los cultivos y su producción de biomasa. A pesar de su importancia, usualmente no se miden de manera directa debido al tiempo invertido y costo; sin embargo, se pueden estimar a gran escala y en tiempo casi real mediante información espectral captada en imágenes de satélite, pero esto requiere de su validación a nivel de campo. Se desarrollaron y validaron modelos de regresión lineal simple utilizando 13 índices de vegetación (IV) relacionados con el IAF y la FCV en alfalfa (Medicago sativa). Se usaron tres fuentes de información espectral: (i) La reflectancia para derivar los IV; (ii) fotografías digitales procesadas con Canopeo para estimar la FCV; y (iii) mediciones del IAF utilizando un ceptómetro. Se realizaron seis muestreos de campo entre marzo y junio de 2020, en cuatro parcelas de alfalfa situadas en Palmar de Bravo, Puebla, México. Para evaluar cada IV, se utilizó el coeficiente de determinación (R2) y la raíz del cuadrado medio del error (RCME). Se encontró que el IV más apropiado para estimar la FCV fue el VIgreen (Green Vegetation Index, R2 = 0.987 y RCME = 0.093). En el caso del IAF, el IV que presentó el mejor desempeño fue el Normalized Difference Vegetation Index (NDVI), R2 = 0.935 y RCME = 0.746). Los resultados mostraron la aptitud y utilidad práctica de la información espectral para estimar las variables biofísicas en el cultivo de alfalfa y su monitoreo.

Resumen Este estudio, se centra en la cobertura forestal de tres distritos en el ámbito urbano de la provincia de Andahuaylas, región Apurímac en Perú, la cual afronta problemas de deforestación. El objetivo fue determinar la cobertura forestal en el área urbana de la provincia de Andahuaylas hasta el 2030, para la revelación de los escenarios futuros de la cobertura forestal, contribuyendo al desarrollo de la planificación urbana y a la creación de ciudades sostenibles. Para el área de estudio, se utilizaron datos registrados entre los años 2017-2023, a partir de las imágenes NDVI del portal Sentinelhub. Permitiendo disponer de información de bosques tropicales y templados; arbustos y pastizales; zonas áridas de roca; áreas urbanas o artificiales que han cambiado como consecuencia del proceso de urbanización. Se determinaron las superficies de bosque en el área de estudio. Posteriormente se utilizó la regresión lineal con un p valor = 0,046, alcanzando un R2 de 0,583 en un rango medio, logrando estimar los escenarios futuros del bosque al 2030. Se concluye que la tendencia es decreciente en la cobertura forestal en 26,50% al año 2030.

Absttract This study focuses on the forest cover of three districts in the urban area of the province of Andahuaylas, Apurímac region, Peru, which is facing deforestation problems. The objective was to determine the forest cover in the urban area of the province of Andahuaylas until 2030, to reveal future scenarios of forest cover, contributing to the development of urban planning and the creation of sustainable cities. For the study area, data recorded between the years 2017-2023 were used, based on NDVI images from the Sentinelhub portal. This allowed for the availability of information on tropical and temperate forests, shrubs and grasslands, arid rock zones, and urban or artificial areas that have changed due to the urbanization process. The forest surfaces in the study area were determined. Subsequently, linear regression was used with a p-value = 0,046, reaching an R2 of 0,583 in a medium range, managing to estimate future forest scenarios by 2030. It is concluded that the trend is decreasing in forest cover by 26,50% by the year 2030.

Summary: The middle area of the state of Sinaloa in Northwestern Mexico is characterized by a warm semi-arid climate where rainfall is insufficient for the adequate development of some introduced plant species. For example, those that correspond to the genus Brachiaria, despite technological advances in sencor development, the producers have limted access to sufficient meteorological information. Therefore, the aim in the present study is to determine water requirement, crop coefficient, and productivity of Convert 300 hybrid grass (Brachiaria sp) in a warm semiarid climate of Mexico by using the Food and Agriculture Organization (FAO56 Penman-Montiel equation) method with complete and limited data; a meteorological station was used to measure climatic parameters, and the FAO56 method with dual kc was applied to estimate crop evapotranspiration under non-standard conditions, and subsequently, water productiviy. The estimated water consumption for the Convert 330 hybrid in the warm semiarid climate of northwest Mexico was 1849 mm with measured data and 1973.5 mm with limited data. The statistical analyses yielded a coefficient of determination (R2) of 0.92, Willmott’s coefficient of agreement (d) of 0.90, RMSE of 0.694 mm d-1, BIAS of 0.380 mm d-1 and a Nash-Sutcliffe coefficient of efficiency (EF) of 0.98. The kc values were 0.49, 1.11 and 1.04 for initial, middle and end of season, respectively; the water productivity (WUE) was 2.666 kg m-3 for green forage, and 0.726 kg m-3, for dry matter, in the same way, 375.1 and 1378 L kg-1 were required to produce green forage and dry matter, respectively. To conclude, althought the ETc estimation with limited data overestimated the ETc with measured data by 6.7%, statistics showed that the procedure is reliable.

Resumen: La región central del estado de Sinaloa en el noroeste mexicano, se caracteriza por un clima semiárido cálido donde la precipitación es insuficiente para el desarrollo adecuado de algunas especies vegetales introducidas, como las correspondientes al género Brachiaria, a pesar del avance tecnológico en el desarrollo de sensores, es escaso el acceso de los productores a suficiente información meteorológica; el objetivo del presente trabajo consistió en determinar el requerimiento hídrico, coeficiente de cultivo y productividad del pasto híbrido Convert 330 (Brachiaria sp) en un clima semiárido cálido de México, utilizando el método FAO56 con datos medidos y datos limitados; se utilizó una estación meteorológica para medir los parámetros climáticos, y se aplicó el método FAO56 con kc dual para estimar la evapotranspiración de cultivo bajo condiciones no estándar, y posteriormente, la productividad del agua. El consumo de agua estimado para el pasto Convert 330 en clima semiárido cálido del noroeste de México fue de 1849 mm con datos medidos y 1973.5 mm con datos limitados; el análisis estadístico arrojó un coeficiente de determinación (R2) de 0.92, coeficiente de concordancia de Willmott (d) de 0.90, RMSE de 0.694 mm d-1, BIAS=0.380 mm d-1 y un coeficiente de eficiencia de Nash-Sutcliffe (EF) de 0.98. Los valores de kc obtenidos fueron de 0.49, 1.11 y 1.04 paras las etapas inicial, media y final, respectivamente; la productividad del agua (EUA) fue de 2.666 kg m-3 para forraje verde y 0.726 kg m-3 para materia seca; asimismo, se requirieron 375.1 y 1378 L kg-1 para la producción de forraje verde y materia seca, respectivamente. Finalmente, se concluye que, aunque la estimación de la ETc con datos limitados sobrestimó en un 6.7% la ETc con datos medidos, la estadística muestra que es confiable el procedimiento.

Abstract: The aim of this work is to put forward a methodology to evaluate the oscillatory stability of a power electric system (PES) analyzing the low-frequency oscillatory modes (LFOM) through the processing of synchrophasor measurements Phasor Measurement Units (PMU) of ambient data. The proposed methodology, based on spectral and pseudo-energy analyses and on parametric methods of Canonical Correlation Analysis and Yule-Walker, estimates the LFOM, whose frequency and damping characteristics provide critical information to PES operators to carry out preventive or emergency control actions. The proposed methodology was applied to synthetic measurements for its tuning and to characterize its range and accuracy, and to PMU records of the Ecuadorian power transmission system, successfully identifying the 0.4 Hz inter-area mode of the Ecuador-Colombia interconnection. The contributions of this work are aimed at evaluating the oscillatory stability of the PES through automatic computational tool that processes PMU signals of ambient type data.

Resumen: El objetivo de este trabajo es presentar una metodología para evaluar la estabilidad oscilatoria de un sistema eléctrico de potencia (SEP) mediante el análisis de los modos oscilatorios de baja frecuencia (MOBF) a través del procesamiento de mediciones sincrofasoriales (Phasor Measurement Units PMU) de datos tipo ambiente. La metodología propuesta, basada en los análisis espectral y de pseudoenergía y en los métodos paramétricos de Análisis de Correlación Canónica y de Yule - Walker, estima los MOBF, cuyas características de frecuencia y amortiguamiento brindan información crítica a los operadores del SEP para adoptar acciones de control preventivo o de emergencia. La metodología propuesta fue aplicada a mediciones sintéticas para su sintonización y caracterizar su alcance y precisión, y a registros PMU del sistema de transmisión de energía de Ecuador logrando identificar satisfactoriamente el modo interárea de 0,4 Hz propio de la interconexión Ecuador-Colombia. Las contribuciones de este trabajo están encaminadas a evaluar la estabilidad oscilatoria de los SEP a través de una herramienta computacional automática que procese señales PMU de datos tipo ambiente.

Abstract: This paper presents a methodology, based on frequency response models, to estimate the minimum or maximum value -nadir- that the frequency reaches when a generation - load unbalance occurs in the power system. To this end, the 1st order reduced equivalent model of the generator’s power-frequency control system is determined using the "Parameter Estimator" of Matlab/Simulink. Then, a set of equations coming from the reduced equivalent model is established to estimate the value of the maximum transient frequency deviation and its occurrence time. To illustrate the application of the proposed methodology, the IEEE New England test system has been chosen. Once this is done, the proposed methodology is applied to the Ecuadorian Interconnected Power System. The results of time domain simulations using the PowerFactory software are presented and compared with the results calculated using the developed reduced and analytical models. It is concluded that the proposed methodology estimates with high accuracy the maximum transient frequency deviation and its time of occurrence.

Resumen: En el presente trabajo se presenta una metodología, basada en modelos de repuesta de la frecuencia, para estimar el valor mínimo o máximo -nadir- que alcanza la frecuencia cuando en el sistema eléctrico de potencia se presenta un desbalance generación - carga. Con este fin, se determina el modelo reducido de 1er orden del sistema de control potencia - frecuencia del generador usando el “Estimador de Parámetros” de Matlab/Simulink. Luego, se establecen ecuaciones que provienen del modelo equivalente reducido para estimar el valor de la máxima desviación transitoria de la frecuencia y su tiempo de ocurrencia. Para ilustrar la aplicación de la metodología presentada se ha elegido el sistema de prueba IEEE New England de 39 barras y 10 generadores. Hecho esto, la metodología propuesta se aplica al Sistema Nacional Interconectado ecuatoriano. Se presentan resultados de simulaciones en el dominio del tiempo usando el programa PowerFactory, mismos que son comparados con los resultados calculados mediante el modelo equivalente reducido y el modelo analítico. Se concluye que la metodología propuesta estima con alta precisión la máxima desviación transitoria de la frecuencia y su tiempo de ocurrencia.

Abstract: The integration of electric mobility is real nowadays. Government policies increasingly focus on encouraging the use of electric vehicles (EVs); particularly, replacing conventional public mobility with electric buses. An adequate energy management of electric bus systems must optimize resource usage, and extend the lifespan of transport units and charging stations, while providing quality service to users. The performance of the EV transport system depends on various deterministic and stochastic variables that need to be accurately simulated to analyze its behavior as closely as possible to real conditions. In this study, a model for the energy analysis of EVs has been implemented, by using the software SUMO (Simulation of Urban Mobility) and applying it to public transport routes in Quito, Ecuador. Through the executed simulations, energy consumption has been estimated and, a sensitivity analysis of the energy consumption of electric bus units to the variations in relevant parameters in the energy management of public transport systems, has been carried out. The impact of certain parameters on energy consumption has been verified, by indicating a significant decrease in the autonomy of EVs on the simulated route under very similar to reality operating conditions. For study case, autonomy reduction of electric bus is around 27% in comparison with manufacturer's specifications. The analysis of energy performance under various traffic scenarios will allow future optimizations of the electric public transport system operation, since traffic levels, variable traffic flow, and pronounced changes in terrain elevation, are considered.

Resumen: La integración de la movilidad eléctrica es una realidad en el mundo actual, las políticas gubernamentales se enfocan cada vez más en incentivar el uso de vehículos eléctricos (VE) particulares, pero, principalmente en reemplazar la movilidad pública convencional por el uso de buses eléctricos. Una adecuada gestión energética de los sistemas de buses eléctricos debe optimizar el uso de recursos, prolongando la vida útil de las unidades de transporte, estaciones de carga y brindando siempre un servicio de calidad a sus usuarios. El desempeño del sistema de transporte mediante VE depende de diversas variables determinísticas y estocásticas que necesitan ser debidamente simuladas a fin de analizar su comportamiento, lo más cercano a las condiciones reales. En el presente trabajo, mediante la aplicación del software SUMO (Simulation of Urban Mobility), se ha implementado un modelo para el análisis energético de VE y se lo ha aplicado en rutas de transporte público en Quito-Ecuador. A partir de las simulaciones realizadas se ha estimado el consumo energético y se ha efectuado un análisis de sensibilidad del consumo energético de las unidades de buses eléctricos ante variaciones de parámetros relevantes en la gestión energética de sistemas de transporte público. Para el caso de estudio se comprueba la reducción de la autonomía del bus eléctrico en 27% de acuerdo con la información del fabricante. El análisis del desempeño energético realizado bajo diversos escenarios de tráfico permitirá en futuros trabajos optimizar la operación de los sistemas de transporte público eléctrico, considerando niveles de tráfico, flujo vehicular variable y pronunciados desniveles en su relieve.

Summary: A methodology is proposed for the interpretation of gas emissions that come from the soil based on the integration of the primary actors in the production systems and members of the ecosystems. The methodology presents data in units that are easy to understand by people outside the study of gas emissions in different ecosystems and production systems, and optimizes the calculation of small and medium scale predictions through estimation with a high degree of ratio and mathematical adjustment. From the use of the ideal gas equation, it was possible to develop the methodology to obtain a conversion factor taking into account variables such as the pressure and temperature of the site where the gas quantification experiment is being carried out. With the aforementioned, it is easier to obtain the constant of the molar volume of the container used and data transformation to ensure compliance with basic statistical parameters such as normality, variance similar to zero, and confidence intervals with less deviation. The present methodological development represents a tool for the generation of data at the laboratory and plot level with mathematical support that facilitates the execution of mathematical models in comparison with other methodologies.

Resumen: Se propone una metodología para la interpretación de las emisiones de gases que proceden del suelo a partir de la integración de los actores primarios en los sistemas de producción e integrantes de los ecosistemas. La metodología presenta datos en unidades de fácil comprensión por personas ajenas al estudio de emisiones de gases en los distintos ecosistemas y sistemas de producción, optimiza el cálculo de predicciones a pequeña y mediana escala mediante la estimación con alto grado de razón y ajuste matemático. A partir del empleo de la ecuación general de los gases ideales se pudo desarrollar la metodología para obtener un factor de conversión teniendo en cuenta variables como la presión y temperatura del sitio donde se esté ejecutando el experimento de cuantificación de gases, con lo anterior se facilita la obtención de la constante del volumen molar propio del contenedor utilizado y la transformación de datos para garantizar el cumplimiento de parámetros estadísticos básicos como normalidad, varianza similar a cero e intervalos de confianza con menor desviación. El presente desarrollo metodológico representa una herramienta para la generación de datos a nivel de laboratorio y parcelario con soporte matemático que facilita la ejecución de modelos matemáticos en comparación con otras metodologías.

Resumen (Objetivo) El objetivo del documento es verificar la estructura factorial de la Escala de Clima Escolar en Ambientes Universitarios (ECEAU) mediante modelos de ecuaciones estructurales (SEM). (Metodología) Se realizó un estudio transversal no experimental con una muestra aleatoria de 381 estudiantes de la Universidad Nacional de Costa Rica, a los que se le aplicó la ECEAU. Se planteó un modelo SEM para verificar la estructura factorial de la escala y un análisis factorial exploratorio (AFE) que brindó la base para proponer un modelo SEM alternativo con una estructura distinta. La confiabilidad de las escalas se determinó mediante el omega de McDonald y los criterios de bondad de ajuste para los modelos SEM fueron el RMSEA, el CFI, el TLI y el GFI. El análisis se efectuó con el software R. (Resultados) La confiabilidad de las escalas en ambos modelos resultaron adecuadas (w >0.70), aunque mejores en el modelo propuesto. El AFE sugirió una estructura diferente para la ECEAU, manteniendo algunas dimensiones de la estructura original y modificando y eliminando otras. Los indicadores de bondad de ajuste, en ambos modelos, fueron casi idénticos con RMSEA=0.02, CFI=0.99, el TLI=0.99 y GFI=0.98, lo que brinda evidencia a favor de las estructuras factoriales planteadas. (Conclusiones) Se verifica la estructura originalmente planteada en la ECEAU y las diferencias en los métodos de estimación y rotación generaron la propuesta de otra estructura factorial, igualmente válida, para medir el constructo clima escolar, en el contexto universitario estudiado y que puede ser aplicado a contextos similares.

Resumo (Objetivo) O objetivo do artigo é verificar a estrutura fatorial da Escala de Clima Escolar em Ambientes Universitários (ECEAU) usando modelagem de equações estruturais (SEM). (Metodologia) Foi realizado um estudo transversal não experimental com uma amostra aleatória de 381 alunos da Universidade Nacional da Costa Rica, aos quais foi aplicada a ECEAU. Uma modelagem SEM foi usada para verificar a estrutura fatorial da escala e uma análise fatorial exploratória (AFE) forneceu a base para a proposta de uma modelagem SEM alternativa com uma estrutura diferente. A confiabilidade das escalas foi determinada pelo ômega de McDonald e os critérios de adequação dos modelos SEM foram RMSEA, CFI, TLI e GFI. A análise foi realizada com o software R. (Resultados) A confiabilidade das escalas em ambos os modelos foi adequada (w >0,70), embora melhor no modelo proposto. A AFE sugeriu uma estrutura diferente para a ECEAU, mantendo algumas dimensões da estrutura original e modificando e eliminando outras. Os indicadores de adequação em ambos os modelos foram quase idênticos, com RMSEA=0,02, CFI=0,99, TLI=0,99 e GFI=0,98, o que fornece evidências a favor das estruturas de fatores propostas. (Conclusões) Confirmou-se a estrutura originalmente proposta no ECEAU e as diferenças nos métodos de estimativa e rotação geraram a proposta de outra estrutura fatorial, igualmente válida, para medir o construto clima escolar no contexto universitário estudado e que pode ser aplicada a contextos semelhantes.

Abstract (Objective) The aim of this paper is to verify the factorial structure of the School Climate Scale in University Environments (ECEAU) through structural equation models (SEM). (Methodology) A non-experimental cross-sectional study was carried out with a random sample of 381 students of the Universidad Nacional de Costa Rica (UNA), to whom the ECEAU was applied. A SEM model was proposed to confirm the factor structure of the scale and an exploratory factor analysis (EFA) was used to provide the basis for an alternative SEM model with a different structure. The reliability of scales was determined using McDonald’s omega, and the goodness of fit indexes used for the SEM models were the RMSEA, the CFI, the TLI and the GFI. The analysis was carried out using R software. (Results) The reliability of the scales in both models was adequate (w>0.70), although the metrics in the proposed model produced better results. The AFE suggested a different structure for the ECEAU, keeping some dimensions of the original structure and modifying and eliminating others. The goodness of fit indexes in both models were almost identical, with RMSEA=0.02, CFI=0.99, TLI=0.99 and GFI=0.98, which provides supporting evidence for the factorial structures proposed. (Conclusions) The original structure of the ECEAU was confirmed, while the differences in the results of the estimation and rotation methods generated another equally valid factorial structure for measuring the school climate construct in this university, and could be applied to other similar contexts.