Predicción de la evapotranspiración de referencia mediante redes neuronales artificiales

JUAN MANUEL GONZALEZ CAMACHO ROCIO CERVANTES-OSORNIO WALDO OJEDA BUSTAMANTE IRINEO LORENZO LOPEZ CRUZ (2008, [Artículo])

La evapotranspiración de referencia (ETo) es una variable climática esencial para el cálculo de los requerimientos hídricos de los cultivos. Su previsión a corto plazo es importante para programar la distribución de volúmenes de agua en las zonas de riego. En este trabajo se presenta la aplicación de un modelo de Red Neuronal Artificial (RNA) tipo feedforward backpropagation para predecir la ETo a partir de datos diarios de temperatura del aire, radiación solar, humedad relativa y velocidad del viento. La arquitectura adoptada del modelo de RNA contiene cuatro neuronas en la capa intermedia, una neurona en la capa de salida y funciones de activación tangente hiperbólica en ambas capas. Este modelo fue aplicado a un conjunto de datos climáticos con cinco años de observaciones de la red agroclimática “Valle del Fuerte” del distrito de riego 075, localizada en el norte de Sinaloa, México. El algoritmo de entrenamiento supervisado de Levenberg-Marquardt permitió obtener un buen desempeño de la red en términos del error cuadrático medio y del coeficiente de determinación R2 para estimar la ETo en los diferentes escenarios considerados. Las predicciones de las RNA fueron comparadas con las predicciones de modelos de regresión lineal múltiple y lineal por partes; los resultados muestran que ambos modelos presentan niveles de ajuste muy similares a los datos experimentales.

Evapotranspiración Requerimientos de riego Variables climáticas Distritos de riego Regresión no lineal Redes neuronales artificiales CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

GENERAL STUDY OF CLASSICAL AND NONCLASSICAL CONTRIBUTIONS OF TWO PHOTON ABSORPTION PROCESS IN ORGANIC MOLECULES

Freiman Estiven Triana Arango (2023, [Tesis de doctorado])

"Two-photon absorption (TPA), a nonlinear optical phenomenon, is gaining attention for applications like laser scanning, microscopy, and therapy. Recent research explores entangled two photon absorption (ETPA) using correlated photons but faces debates regarding its magnitude and detection. This study introduces a novel method using changes in Hong-Ou-Mandel (HOM) interferogram visibility to probe ETPA's presence. It employs Rhodamine B dye and entangled photons at around 800nm to investigate conditions conducive to observing ETPA-induced changes. This innovative approach distinguishes genuine ETPA signals from linear optical losses often masquerading as ETPA effects, addressing a significant field challenge."

Two-photon absorption Entangled two-photon absorption Hong-Ou-Mandel HOM dip visibility Joint Spectral Intensity Entangled photons CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA OPTICA NO LINEAL OPTICA NO LINEAL

Análisis cuantitativo con diagrama de precedencias de condiciones productivas actuales de 5 líneas de ensamble de amortiguadores mediante el método de balanceo peso posicional

José Humberto Vergara García (2023, [Tesis de maestría])

En este trabajo de investigación se empleó el método de Helgeson & Birnie para realizar el balanceo por peso posicional de cinco líneas de ensamble modular de amortiguadores de la empresa ZF Suspension Technology Guadalajara S.A. de C.V. La metodología empleada permitió establecer las condiciones actuales de operación de las cinco líneas. Mediante el uso del método mencionado se encontró que en la mayoría de las líneas de ensamble analizadas sus tareas se encuentran correctamente balanceadas y ordenadas, corroborando así el buen trabajo realizado al momento de su instalación y puesta en marcha. Si bien en cualquier proceso de ensamble siempre hay oportunidades de mejora, contar con líneas de ensamble bien balanceadas permite a la empresa tener una base sólida para la producción de este tipo de componentes automotrices.

The Helgeson & Birnie method was employed in this research for balancing, by positional weight, five modular strut assembly production lines at ZF Suspension Technology Guadalajara S.A. De C.V. The proposed methodology allowed to know the current operating conditions of the production lines. It was found that most of the analyzed production lines are correctly balanced suggesting a correct commissioning and start up procedure performed when the lines were initially installed. Although every assembling line always can be improved, having well-balanced assembly lines provides a solid base line for any automotive manufacturing company.

Líneas de ensamble modular Método de Helgeson & Birnie Peso posicional Final assembly lines Helgeson & Birnie method Positional weight INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Teacher training in the state of Chihuahua: Between the health challenge and teacher resilience

Evangelina Cervantes Holguín Pavel Roel Gutiérrez Sandoval Cely Celene Ronquillo Chávez (2023, [Artículo, Artículo])

The article proposes to recover the response of the Teacher Training and Updating Institutions in the state of Chihuahua regarding the various challenges imposed by the Coronavirus Disease (COVID-19). The qualitative exercise analyzes the experience of 10 institutions based on the voice of their students, teachers, and principals regarding changes in academic, administrative, and organizational processes. It is concluded that the pandemic has affected each institution in different ways and with diverse intensity. Despite the achievements, the experience analyzed reveals the relative success of the using virtual platforms in the face of three basic conditions: connectivity, technological competencies, and socio-emotional skills of the teaching staff. It highlights the importance of implementing tutoring, resilience, or awareness actions of teachers and students' needs, feelings, and sufferings. It is opportune to recover the experiences of other institutions and to question especially students, thesis students and graduates.

Acceso a la educación Aprendizaje en línea Educación a distancia Formación de docentes Tecnología educacional HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA Access to education online learning distance education teacher education educational technology

Big data, small explanatory and predictive power: Lessons from random forest modeling of on-farm yield variability and implications for data-driven agronomy

Martin van Ittersum (2023, [Artículo])

Context: Collection and analysis of large volumes of on-farm production data are widely seen as key to understanding yield variability among farmers and improving resource-use efficiency. Objective: The aim of this study was to assess the performance of statistical and machine learning methods to explain and predict crop yield across thousands of farmers’ fields in contrasting farming systems worldwide. Methods: A large database of 10,940 field-year combinations from three countries in different stages of agricultural intensification was analyzed. Random effects models were used to partition crop yield variability and random forest models were used to explain and predict crop yield within a cross-validation scheme with data re-sampling over space and time. Results: Yield variability in relative terms was smallest for wheat and barley in the Netherlands and for wheat in Ethiopia, intermediate for rice in the Philippines, and greatest for maize in Ethiopia. Random forest models comprising a total of 87 variables explained a maximum of 65 % of cereal yield variability in the Netherlands and less than 45 % of cereal yield variability in Ethiopia and in the Philippines. Crop management related variables were important to explain and predict cereal yields in Ethiopia, while predictive (i.e., known before the growing season) climatic variables and explanatory (i.e., known during or after the growing season) climatic variables were most important to explain and predict cereal yield variability in the Philippines and in the Netherlands, respectively. Finally, model cross-validation for regions or years not seen during model training reduced the R2 considerably for most crop x country combinations, while for wheat in the Netherlands this was model dependent. Conclusion: Big data from farmers’ fields is useful to explain on-farm yield variability to some extent, but not to predict it across time and space. Significance: The results call for moderate expectations towards big data and machine learning in agronomic studies, particularly for smallholder farms in the tropics where model performance was poorest independently of the variables considered and the cross-validation scheme used.

Model Accuracy Model Precision Linear Mixed Models CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MACHINE LEARNING SUSTAINABLE INTENSIFICATION BIG DATA YIELDS MODELS AGRONOMY

Point placement of late vegetative stage nitrogen splits increase the productivity, N-use efficiency and profitability of tropical maize under decade long conservation agriculture

Hari Sankar Nayak C.M. Parihar Shankar Lal Jat ML JAT Ahmed Abdallah (2022, [Artículo])

Non-Linear Growth Model Nitrogen Remobilization Right Placement Precision Nitrogen Management CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GROWTH MODELS NITROGEN NUTRIENT MANAGEMENT

A pre-pandemic study about recreational uses in the Mexico Park located at Mexico City (year 2017)

Ramiro Flores-Xolocotzi Sergio Ceballos (2022, [Artículo, Artículo])

A recreational study was carried out through surveys in the Parque México in Mexico City. For this, the relationship between visit patterns with socioeconomic information, uses and perceptions of visitors with 18 years old or older was analyzed. This research uses descriptive statistics and a non-linear canonical correlation analysis to analyze relationships between variables. An ordered probit regression was also performed to determine the variables that explain the frequency of recreational use. It was obtained that the Park mainly receives visitors with at least bachelor's degree (78.6%) and high incomes (more than 50% have a monthly family income higher than $10,000.00 pesos and 27.6% receive more than $30,000.00 per month). Considering the results, the conclusions are that although the highest percentage of the studied population comes from neighborhoods outside the Roma-Condesa Corridor: then the visitors who live in the Corridor and who have higher incomes, have weight in the description of the model. The results allow to conclude too, that higher income increases the frequency of use. It is also observed that the park is used during the Monday to Friday by more than 50% of the population of visitors and with a high percentage of use in the mornings.

urban forestry urban planning leisure green areas correlación canónica no lineal parque urbano probit recreación CIENCIAS SOCIALES CIENCIAS SOCIALES

SNP discovery using BSR-Seq approach for spot blotch resistance in wheat (Triticum aestivum L.), an essential crop for food security

Vinod Mishra Ramesh Chand UTTAM KUMAR Apurba Chowdhury arun joshi (2022, [Artículo])

Spot Blotch Recombinant Inbred Lines Bulk Segregant Analysis CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA WHEAT FOOD SECURITY SINGLE NUCLEOTIDE POLYMORPHISM DISEASE RESISTANCE

Response of African sorghum genotypes for drought tolerance under variable environments

Hussein Shimelis Baloua Nébié (2023, [Artículo])

Additive Main Effect and Multiplicative Interaction Best Linear Unbiased Estimates Drought Tolerance Indices CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA ABIOTIC STRESS DROUGHT TOLERANCE SORGHUM GENOTYPES

Complex traits and candidate genes: estimation of genetic variance components across multiple genetic architectures

GIOVANNY COVARRUBIAS-PAZARAN Hans-Peter Piepho (2023, [Artículo])

Average Semivariance Linear Mixed Model Variance Component Estimation Polygenic Inheritance Oligogenic Inheritance Mendelian Inheritance CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MENDELISM GENETIC VARIANCE GENOME-WIDE ASSOCIATION STUDIES PHENOTYPES CHROMOSOME MAPPING