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Minimizing the carbon footprint in LoRa-Based IoT networks: A machine learning perspective on gateway positioning
Get PDFThe Internet of Things (IoT) is gaining significant attention for its ability to digitally transform various sectors by enabling seamless connectivity and data exchange. However, deploying these networks is challenging due to the need to tailor configurations to diverse application requirements. To date, there has been limited focus on examining and enhancing the carbon footprint (CF) associated with these network deployments. In this study, we present an optimization framework leveraging machine learning techniques to minimize the CF associated with IoT multi-hop network deployments by varying the placement of the required gateways. Additionally, we establish a direct comparison between our proposed machine learning method and the integer linear program (ILP) approach. Our findings reveal that placing gateways using neural networks can achieve a 14% reduction in the CF for simple networks compared to those not using optimization for gateway placement. The ILP method could reduce the CF by 16.6% for identical networks, although it incurs a computational cost more than 250 times higher, which has its own environmental impact. Furthermore, we highlight the superior scalability of machine learning techniques, particularly advantageous for larger networks, as discussed in our concluding remarks.This work was supported in part by MICIU/AEI/10.13039/501100011033 and FEDER, EU, under Grant PID2023-148214OB-C21, in part by MCIN/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR under Grant TED2021-129336B-I00, and in part by Fundación Séneca under Grant 22236/PDC/23. The work of Francisco-Jose Alvarado-Alcon was supported by the Spain’s Ministry of Universities under Grant FPU22/00316
Machine-learning-based urban path loss prediction at 900 MHz: principal component analysis, clustering, feature importance and regression
Get PDFIn this work, the possibility of applying machine learning (ML) techniques to analyze and predict radio wave propagation losses in urban environments is explored. Thus, from a measurement campaign–conducted at 900 MHz in Cartagena, Spain– and the obtaining, by means of digital terrain and cadastral maps, of a series of relevant geospatial variables, urban path loss is analyzed through clustering methods and principal component analysis (PCA), as well as predicted using multivariate MLbased regression models. A feature importance analysis is also carried out to identify key independent variables (predictors) which can be crucial for improved path loss prediction. The results obtained show how parameters such as the total distance between the transmitter (Tx) and the receiver (Rx), the number of intersected elements or the final free distance between the last obstacle and the Rx can be essential to differentiate the four clusters which are identified from the path loss measurements. Additionally, among all the algorithms analyzed–Gradient Boosting (GB), k-Nearest Neighbors (kNN), neural networks (NN), and Support Vector Machines (SVM)–, GB has proved to be the most robust across all clusters when it comes to predicting propagation losses. On the contrary, when evaluating the models for path loss prediction on the entire dataset (without distinguishing clusters), kNN has achieved the lowest test RMSE, the highest R2, and the smallest MAPE, with the total Tx-Rx distance, the final free distance and the average free distance emerging as the most critical features for enhanced path-loss prediction.This work was supported in part by the Ministerio de Ciencia e Innovación, Spain, funded by MCIN/AEI/10.13039/501100011033 under Grant PID2022-136869NB-C32 and in part by the European Union. The work of Ignacio Rodríguez-Rodríguez was supported in part by MICIU/AEI/10.13039/501100011033 under Grant RYC2023-045296-I and in part by the European Social Fund Plus
La ciencia abierta, bien común
Get PDFLa ciencia abierta es un bien común accesible, que permite una participación abierta de la sociedad en los procesos científicos y no mercantilizado, con resultados de investigación financiados por fondos públicos abiertos a la sociedad. Los resultados de investigación son diversos: publicaciones científicas, datos, códigos y metodologías
Analysis of variables affecting employees’ absenteeism in a special employment center
Get PDFScholars have been paying increasing attention to absenteeism since it has relevant effects on the success of organizations1,2 and has increased substantially in the last few years. The growth in the trend of absenteeism has become significantly more evident following the COVID-19 pandemic, increasing by 31.48% in 2020 and 25% in 2021.3 There is no unique accepted definition of absenteeism in the academic literature. The concept of absenteeism offered by the Royal Academy of the Spanish Language (RAE) defines it as the “deliberate abstention from going to the place where an obligation is fulfilled”, which in this case refers to the obligation to work. The International Labour Organization refers to the use of the variable “hours of absence,” and identifies labor absenteeism as the number of hours not worked compared to the number of contractual hours in a period of reference time. Although the hours of absence may be the result of aspects related to vacations, professional illnesses or injuries, paid leave, provision of care to third parties, weather factors, or other reasons of a personal nature, this paper applies the definition of Hamoui,4 for whom absenteeism is “a situation in which the worker does not show up at his/her job or comes fewer hours than stipulated, when the organization expected him/her to come or stay in the post.” Thus, to establish a definition of absenteeism in this paper, the above definitions have been taken as a reference and complemented with the indications of Article 52 of the Spanish Workers’ Statute,5 which specifies that the following situations are not considered absenteeism:
− General strike periods.
− Leaves established in Labor Legislation (maternity, paternity, leave of absence, etc.).
− Vacation periods.
Concerning the contribution of the European Observatory of Working Conditions, although it does not provide a concise definition of absenteeism, it refers to an internationally accepted definition as the manifestation of a worker's decision not to report to their workplace at a time when attendance has been planned by management. However, this definition is only a starting point since, in practice, national data considers many different definitions.6
Absenteeism has traditionally been recognized as a key issue for HRM, particularly as it has relevant effects on organizations’ performance and competitiveness.1,2 The data on total loss of working hours cited in the “Adecco Report on Healthy Company and Absenteeism Management”7 in Spain is worth mentioning since it reached almost 1700 million hours, which, in terms of people, would be equivalent to 937,000 employees not working throughout the year. Furthermore, the trend toward absenteeism has been growing since 2017. The absenteeism rate ranged between 4.8% and 5.3% from 2016 to 2018. However, during the years of the COVID-19 pandemic, it increased to 7.1% in 2020 and 8.9% in 2021, according to the Randstad Report.8 This growth in the trend of absenteeism is even more evident if an analysis of increases in annual absenteeism rates is considered. In this case, these annual rises did not exceed the 6% threshold until the start of the COVID-19 pandemic, the appearance of which led to increases of 31.48% in 2020 and 25% in 2021.3 Although labor absenteeism has grown considerably in all industrialized countries during the last decade, data from recent years reveal a significant increase in this trend.3 In Spain, for example, the number of hours not worked grew from 1250 million in 2017 to 1700 million hours not worked in 2020.7 It is important, first of all, to highlight the different causes that can lead to a situation of absenteeism from work. These include:
− Workers’personal characteristics
− Organizational characteristics
− Economic and health situations
The personal characteristics of workers have been derived from various demographic variables,9 while the organizational characteristics relate absenteeism to the company sector and size, with healthcare activities accounting for the highest rates of absenteeism.10 Economic and health situations are other relevant factors in absenteeism from work. In these cases, the COVID-19 pandemic had an influence, with an average annual loss of 108 h per worker in Spain in 2020.11 Finally, these causes can be added to others related to job security, where it is important to guarantee adequate working conditions and the prevention and surveillance of health risks that can lead to absenteeism.12 In short, there are many causes of absenteeism, which highlights the need for a deeper analysis of these variables. Absenteeism can have a significant impact on the company's bottom line.13,14 When employees are absent, it can disrupt workflow and substantially reduce productivity,15 leading to delays and increased expenses. High absenteeism rates can also contribute to a negative work culture and morale among the remaining staff.16–18 Additionally, frequent absenteeism can indicate deeper issues within the company, such as poor management or lack of engagement.9,19,20 Therefore, it is important for firms to track and address absenteeism to ensure the overall health and success of their organizations. Nowadays, people with disabilities still face significant barriers to employment and often have higher rates of unemployment than the general population. The main reason for this disparity has to do with possible problems arising from the health of people with disabilities.21 However, disabled employees comprise a significant percentage of the workforce and are found to be less absent than workers without disabilities.22 Even so, absenteeism among this group is important to consider. There has been little research on inclusive Human Resource Management (HRM) and the outcomes of this collective.11 This research helps fill this gap in the literature by addressing the absenteeism issue in a Special Employment Center (SEC) through the analysis of some factors that can affect absenteeism. In this way, we aim to establish some human resource policies to address this issue.
This paper presents a longitudinal empirical analysis of the real levels of absences and days worked among the employees of an SEC in the city of Cartagena (Murcia, Spain) from the data provided by a historical series between the years 2019 and 2021. Results are presented and discussed within the framework of the COVID-19 pandemic. The paper then elaborates different proposals for improvement in this SEC. Finally, limitations and future research lines are highlighted
Introducción a la comunicación científico-divulgativa como medio de autoevaluación entre estudiantes
Get PDFLa comunicación científica es una competencia clave en la formación académica y profesional del estudiantado universitario. Sin embargo, las estructuras y el lenguaje utilizados en artículos académicos o informes técnicos pueden resultar poco accesibles para quienes se enfrentan a ellos por primera vez. A su vez, la creciente demanda de transmitir información científica a públicos no especializados exige que los futuros egresados sean capaces de adaptar sus mensajes según el tipo de audiencia. Este Proyecto de Innovación Docente propuso una estrategia doble para fomentar la comprensión y práctica de la comunicación científica y divulgativa mediante la autoevaluación activa del alumnado.Este proyecto asociado al Proyecto de Innovación Docente 2024 PRIMED 2024 SEFYCU 3018987.. EG-G, GBMH y NC están financiados por el programa Beatriz Galindo del Ministerio de Universidades (BG22/00060, BG20/00069 y BG23/00121 respectivamente). AG está financiado por el programa Ramón y Cajal (RYC-2021-034612-I)
Ricardo Velázquez Bosco and Guadalajara the Duchess of Sevillano
Get PDF[ENG] Ricardo Velázquez Bosco is one of the main representatives of eclectic architecture in Spain. His professional activity was developed mainly for the Administration, being very few private clients for whom he worked. Among them was the Duchess of Sevillano for whom, in Guadalajara, he built a palace, a complex of asylums, a church dedicated to Santa María Micaela and a family pantheon, and on the outskirts of the city, an agricultural village. Also in Guadalajara, working for the Administration, he restored the Chapel of Luis de Lucena and reformed the old Convent of La Piedad to adapt it to a Teaching Institute. In spite of his numerous and important works, few original documents are preserved. This paper aims to transmit the results of the research project, funded by the Cortes de Castilla La Mancha, developed during 2023, the year that commemorated the first centenary of the death of this architect, which concluded with an exhibition held at the Museum of Guadalajara. The exhibition was structured in three blocks, the first showing an image of the city in the last third of the nineteenth century, the second, dedicated to the work of Velázquez in Guadalajara, included the surveys of his works that, to a large extent, are the result of previous work done at the School of Technical Architecture of Guadalajara, and the third, a sample of the new architecture, contemporary of Velázquez Bosco, in the city. [SPA] Ricardo Velázquez Bosco es uno de los principales representantes de la arquitectura ecléctica en España. Su actividad profesional la desarrolló fundamentalmente para la Administración, siendo muy pocos los clientes particulares para los que trabajó. Entre ellos se encontraba la Duquesa de Sevillano ipara la que, en Guadalajara, construyó un Palacio, un conjunto formado por Asilos, una Iglesia dedicada a Santa María Micaela y un Panteón Familiar, y en las afueras de la ciudad, un poblado agrícola. También en Guadalajara, trabajando para la Administración, restauró la Capilla de Luis de Lucena y reformó el antiguo Convento de la Piedad para adaptarlo a Instituto de Enseñanza. A pesar de lo numerosa e importante que es su obra, son pocos los documentos originales que se conservan de ella. Con la presente comunicación se pretende transmitir los resultados del proyecto de investigación, financiado por las Cortes de Castilla La Mancha, desarrollado durante 2023, año que se conmemoraba el primer centenario de la muerte de este arquitecto, que concluyó con una exposición celebrada en el Museo de Guadalajara. La exposición se estructuraba en tres bloques, en el primero se mostraba una imagen de la ciudad en el último tercio del siglo XIX, en el segundo, el dedicado a la obra de Velázquez en Guadalajara, se recogían los levantamientos de sus obras que, en gran medida, son fruto de trabajos previos realizados en la Escuela de Arquitectura Técnica de Guadalajara y en el tercero, una muestra de la nueva arquitectura, contemporánea de Velázquez Bosco, en la ciudad
Environmental Impact Assessment of a 40 MW wind farm in the Sierra de Cartagena
Get PDFEste trabajo se redacta como Estudio de Impacto Ambiental que acompaña al documento inicial del proyecto de PARQUE EÓLICO de La Unión ubicado en el Término Municipal de La Unión en la Región de Murcia. El parque consta de 8 aerogeneradores SG 6.6-155 diseñados por Siemens Gamesa Renewable Energy, lo que nos permitirá tener una potencia instalada de 40 MW.
Este diseño es perfecto para clientes que buscan potencias nominales superiores a 4 MW emplazamiento con vientos bajos, como ocurre en nuestra zona. Su diseño optimizado para velocidades de viento medias, su modularidad y flexibilidad le permiten adaptarse a una amplia gama de sitios.Escuela de Ingeniería de Caminos y MinasUniversidad Politécnica de Cartagen
Analysis and comparison of Urban Mobility Plans: Case studies of Murcia and Utrecht
Get PDF[SPA] Este trabajo examina y compara el urbanismo de Utrecht (Países Bajos) y Murcia (España) con atención especial a los puntos críticos del tejido urbano de ambas para comprender sus puntos fuertes y débiles. A pesar de sus similitudes demográficas y territoriales, estas ciudades adoptan enfoques muy diferentes en cuanto a movilidad y uso del espacio urbano. El objetivo principal es comprender por qué el plan de movilidad de Murcia, respaldado por la Agenda 2030 y que se extiende hasta 2024, no ha logrado el impacto previsto. Para ello, se utiliza como contrapunto la ciudad de Utrecht, cuya estrategia de urbanismo y movilidad ha evolucionado hasta cotas a la altura de las expectativas de dicha Agenda. Se realiza un estudio del contexto urbano de ambas ciudades, se identifican los puntos críticos de circulación y se examinan las soluciones implementadas en Utrecht que podrían servir de referencia. A través de un análisis comparativo, se extraen conclusiones y se proponen mejoras que podrían contribuir a una movilidad más eficiente y sostenible en Murcia. [ENG] This study examines and compares the urban planning of Utrecht (Netherlands) and Murcia (Spain), with special attention to the critical points of the urban fabric in both cities to understand their strengths and weaknesses. Despite their demographic and territorial similarities, these cities adopt very different approaches to mobility and the use of urban space. The main objective is to understand why Murcia's mobility plan, supported by the 2030 Agenda and running until 2024, has failed to achieve the expected impact. To this end, the city of Utrecht is used as a counterpoint, as its urban and mobility strategy has evolved to meet the expectations set by the Agenda. An analysis of the urban context of both cities is carried out, the critical traffic points are identified, and the solutions implemented in Utrecht that could serve as a reference are examined. Through a comparative analysis, conclusions are drawn and improvements are proposed that could contribute to more efficient and sustainable mobility in Murcia.Escuela Técnica Superior de Arquitectura y EdificaciónUniversidad Politécnica de Cartagen
Discovering the ephemeral architecture of Seville's fair gates through QR codes
Get PDF[ENG] This study aims to preserve and promote the heritage of the ephemeral architecture of Seville’s April Fair, represented through its fair gates. It seeks to identify the architectural and ornamental references that have influenced their design and analyse the original traces of these ephemeral constructions, which often imitate existing buildings. To bring the value of these ephemeral structures closer to the public, the project proposes creating city itineraries based on the architectural elements of the buildings that inspired the fair gates. Through plaques with QR codes placed on these buildings, citizens will be able to discover the connection between the permanent city (the reference framework) and the ephemeral one (the festive setting), thus linking existing architecture with the temporary constructions that adorn the fairgrounds. This research will generate a digital and graphic documentary archive on Seville’s ephemeral architecture, specifically focusing on the April Fair’s gates. This initiative will contribute to fostering a culture of innovation and knowledge transfer regarding one of the city's most iconic examples of ephemeral architecture. Beyond visual documentation, this study promotes awareness of Seville’s ephemeral heritage, encouraging its conservation and enhancing appreciation of local identity. Additionally, the creation of urban itineraries represents an innovative approach to connecting the city's architectural past with its present social and cultural landscape. [SPA] Esta comunicación persigue conservar y difundir el patrimonio de la arquitectura efímera de la Feria de Abril de Sevilla, representada mediante sus Portadas de Feria. Se busca identificar los referentes arquitectónicos y ornamentales que han influido en el diseño de las Portadas, así como analizar las trazas originales de estas construcciones efímeras imitadoras en muchos casos de edificios existentes. Para acercar los valores de estas arquitecturas efímeras al público, se propone la creación de itinerarios por la ciudad, basados en los elementos arquitectónicos de los edificios que inspiraron las Portadas. A través de placas con códigos QR situadas en estos edificios, los ciudadanos podrán descubrir la relación entre la ciudad permanente (marco de referencia) y la efímera (escenario de la fiesta), conectando la arquitectura existente con las construcciones temporales que engalanan el Real de la Feria. Este trabajo permitirá generar un fondo documental gráfico y digital sobre la arquitectura efímera sevillana, en particular sobre las Portadas de la Feria de Abril. Este esfuerzo contribuirá al impulso de la cultura de la innovación y la transferencia del conocimiento sobre una de las muestras más icónicas de la arquitectura efímera de la ciudad. Además de la documentación visual, esta investigación promueve dar visibilidad al patrimonio efímero de la ciudad, fomentando la conservación y la sensibilización sobre la identidad local. Asimismo, la creación de itinerarios urbanos representa una forma innovadora de conectar el pasado arquitectónico con el presente social y cultural de Sevilla
Water pavilion for the international exhibition in Liege 1939: Origin of modular architecture in Antonio Bonet Castellana
Get PDF[ENG] If we look at the entire work of Antonio Bonet Castellana we can observe the presence of different geometric patterns. Standardization and repetition as a mechanism to evolve and improve construction solutions gave rise to numerous examples in his architecture that are based on grids, where the repetition of the module organizes the entire project. From 1936 to 1937, during his stay in Paris, Bonet worked in Le Corbusier's studio. There, in collaboration with the Chilean architect and surrealist painter Roberto Matta Echaurren, he designed the Water Pavilion for the International Exhibition in Liege (Belgium) in 1939. The aim of this work is to demonstrate that this is his first project in which, in a clear and intentional way, an architecture based on a modular system with singular geometric forms of covering appears, and which represents the origin of a way of designing that will appear recurrently in his work. For that purpose, we will analyze this project and compare it with Bonet's later projects to see their similarities and the evolution of this way of approaching projects. The results of this work will allow us to understand to what extent geometry, standardization and typological evolution were determining factors in the conception of his projects. Although Bonet's work has been studied from multiple perspectives - urban planning, building and furniture - this study proposes an alternative approach focused on geometric systematization as a key aspect of his architectural thought and material production. [SPA] Si recorremos toda la obra de Antonio Bonet Castellana podemos observar la presencia de distintos patrones geométricos. La estandarización y repetición como mecanismo para evolucionar y mejorar las soluciones constructivas dieron lugar a numerosos ejemplos en su arquitectura que están basados en retículas, donde la repetición del módulo organiza todo el proyecto. Entre 1936 y 1937, durante su estancia en París, Bonet trabajó en el estudio de Le Corbusier. En él realizó, en colaboración con el arquitecto y pintor surrealista chileno, Roberto Matta Echaurren, el proyecto del Pabellón del agua para la Exposición Internacional de Lieja (Bélgica) de 1939. El objetivo de este trabajo es demostrar que este es su primer proyecto donde aparece, de una manera clara e intencionada, una arquitectura basada en un sistema modular con formas geométricas singulares de cubrición, y que supone el origen de una manera de proyectar que aparecerá de manera recurrente en su obra. Para ello analizaremos este proyecto y lo compararemos con proyectos posteriores de Bonet para ver sus similitudes y la evolución que tuvo esa manera de abordar los proyectos. Los resultados de este trabajo permitirán comprender hasta qué punto la geometría, la estandarización y la evolución tipológica fueron factores determinantes en la concepción de sus proyectos. Aunque la obra de Bonet ha sido estudiada desde múltiples perspectivas —urbanismo, edificación y mobiliario—, este estudio propone un enfoque alternativo centrado en la sistematización geométrica como un aspecto clave de su pensamiento arquitectónico y su producción material