Analysis of the Performance of a Passive Downdraught Evaporative Cooling System Driven by Solar Chimneys in a Residential Building by Using an Experimentally Validated TRNSYS Model

[EN] Natural ventilation, combined with a passive cooling system, can provide significant energy savings in the refrigeration of indoor spaces. The performance of these systems is highly dependent on outdoor climatic conditions. The objective of this study was to analyse the feasibility of a passive, downdraught, evaporative cooling system driven by solar chimneys in different climatic zones by using an experimentally validated simulation tool. This tool combined a ventilation model and a thermal model of the dwelling in which an empirical model of a direct evaporative system made of plastic mesh was implemented. For experimental validation of the combined model, sensors were installed in the dwelling and calibrated in the laboratory. The combined model was applied to Spanish and European cities with different climates. In the simulation, values of cooling energy per volume of air ranging between 0.53 Wh/m(3) and 0.79 Wh/m(3) were obtained for Alicante (hot climate with moderate humidity) and Madrid (hot and dry climate), respectively. In these locations, medium and high applicability was obtained, respectively, in comparison with Burgos (cold climate with moderate humidity) and Bilbao (cold and humid climate), which were low. The evaluation of the reference building in each location allowed establishing a classification in terms of performance, comfort and applicability for each climate.This research was funded by FEDER/Ministerio de Ciencia e Innovacion Agencia Estatal de Investigacion through Spanish research projects ENE2017-83729-C3-1-R and ENE2017-83729-C3-3-R, supported by FEDER funds.Soto, A.; Martínez, P.; Soto Francés, VM.; Martínez, PJ. (2021). Analysis of the Performance of a Passive Downdraught Evaporative Cooling System Driven by Solar Chimneys in a Residential Building by Using an Experimentally Validated TRNSYS Model. Energies. 14(12):1-17. https://doi.org/10.3390/en14123486S117141

An urn model for majority voting in classification ensembles

In this work we analyze the class prediction of parallel randomized ensembles by majority voting as an urn model. For a given test instance, the ensemble can be viewed as an urn of marbles of different colors. A marble represents an individual classifier. Its color represents the class label prediction of the corresponding classifier. The sequential querying of classifiers in the ensemble can be seen as draws without replacement from the urn. An analysis of this classical urn model based on the hypergeometric distribution makes it possible to estimate the confidence on the outcome of majority voting when only a fraction of the individual predictions is known. These estimates can be used to speed up the prediction by the ensemble. Specifically, the aggregation of votes can be halted when the confidence in the final prediction is sufficiently high. If one assumes a uniform prior for the distribution of possible votes the analysis is shown to be equivalent to a previous one based on Dirichlet distributions. The advantage of the current approach is that prior knowledge on the possible vote outcomes can be readily incorporated in a Bayesian framework. We show how incorporating this type of problem-specific knowledge into the statistical analysis of majority voting leads to faster classification by the ensemble and allows us to estimate the expected average speed-up beforehandThe authors acknowledge financial support from the Comunidad de Madrid (project CASI-CAMCM S2013/ICE-2845), and from the Spanish Ministerio de Economía y Competitividad (projects TIN2013-42351-P and TIN2015-70308-REDT

A double pruning algorithm for classification ensembles

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-12127-2_11Proceedings of 9th International Workshop, MCS 2010, Cairo, Egypt, April 7-9, 2010.This article introduces a double pruning algorithm that can be used to reduce the storage requirements, speed-up the classification process and improve the performance of parallel ensembles. A key element in the design of the algorithm is the estimation of the class label that the ensemble assigns to a given test instance by polling only a fraction of its classifiers. Instead of applying this form of dynamical (instance-based) pruning to the original ensemble, we propose to apply it to a subset of classifiers selected using standard ensemble pruning techniques. The pruned subensemble is built by first modifying the order in which classifiers are aggregated in the ensemble and then selecting the first classifiers in the ordered sequence. Experiments in benchmark problems illustrate the improvements that can be obtained with this technique. Specifically, using a bagging ensemble of 101 CART trees as a starting point, only the 21 trees of the pruned ordered ensemble need to be stored in memory. Depending on the classification task, on average, only 5 to 12 of these 21 classifiers are queried to compute the predictions. The generalization performance achieved by this double pruning algorithm is similar to pruned ordered bagging and significantly better than standard bagging

Design of a 35 kW Solar Cooling Demonstration Facility for a Hotel in Spain

[EN] Solar cooling systems have the advantage of the coincidence between the hours of cooling demand and the hours of solar radiation availability, and they can contribute to reduce the energy consumption in buildings. However, the high cost of thermal solar cooling facilities with absorption chillers, maintenance issues, legionella risk and water consumption (associated to the necessary cooling tower) have limited the use of these systems to demonstration projects. A simplified Transient System Simulation Tool (TRNSYS) model was developed to provide the owner of the demonstration facility the information he needs for design decision-making. This model was validated with experimental data registered in a solar cooling system designed and built by the authors. Different collector field surfaces, hot water storage tank volumes, and absorption machine driving temperatures were analyzed for a hotel demonstration facility. In terms of the energy delivered to the absorption chiller the optimum dimensioning corresponded to the lowest values of the driving temperature (75 °C) and specific storage volume (15 Lm2). From an economic point of view, the saving of 1515 euros per year when compared with an electric compression chiller does not compensate the investment of 3000 euros per kW of cooling capacity that cost the thermal solar cooling facility.This research was funded by (MINECO/AEI/FEDER, UE), grant number ENE2017-83729-C3-1-R.Martínez, PJ.; Martínez, P.; Soto Francés, VM.; Bujedo, LA.; Rodríguez, J. (2020). Design of a 35 kW Solar Cooling Demonstration Facility for a Hotel in Spain. Applied Sciences. 10(496):1-13. https://doi.org/10.3390/app10020496S1131049

Connectedness to Nature, Well-Being and Presence of Birds

Connectedness to Nature represents a growing area of interest in the latest years because it could have implications in human behavior. In addition, another type of implications studied in people have been the sounds of birds. The aim of this literature review was to analyze the state of knowledge about Connectedness to Nature and birds, as well as its link with variables related to well-being to identify gaps and directions for further research. We reviewed 41 papers published between 2011 and 2021. Papers were found in 29 journals with studies from 16 countries. Eighty-five percent of the papers used an experimental design and there is a trend of increasing publications over time. Our results show that Connectedness to Nature is linked to variables related to well-being, and the presence of birds (or their perception) contributes to explain the relationship. Therefore, more research on the subject is needed because there is evidence that contradicts some findings. Also, research is needed in different bird species, sounds, different cultures and local contexts, thus, it is necessary to study rural and urban areas. In addition, research is needed in children and teenagers who have been very little represented. Finally, it is necessary to have more information from Latin American countries as they represent the most diverse in bird species and to be able to compare with more studied regions like Europe and North America.A A conexão com a natureza representa uma área de interesse crescente nos últimos anos, pois poderia ter implicações no comportamento humano. Além disso, outro tipo de implicações estudadas nas pessoas têm sido os sons das aves. O objetivo desta revisão da literatura foi analisar o estado do conhecimento sobre a Conectividade com a Natureza e as aves, bem como sua ligação com variáveis relacionadas ao bem-estar para identificar lacunas e direções para pesquisas posteriores. Revisamos 41 artigos publicados entre 2011 e 2021. Foram encontrados artigos em 29 periódicos com estudos de 16 países. Oitenta e cinco por cento dos artigos utilizaram um desenho experimental e há uma tendência de aumento das publicações ao longo do tempo. Nossos resultados mostram que a conexão com a natureza está ligada a variáveis relacionadas ao bem-estar, e a presença de aves (ou sua percepção) contribui para explicar a relação. Portanto, mais pesquisas sobre o assunto são necessárias porque há evidências que contradizem algumas descobertas. Além disso, a pesquisa é necessária em diferentes espécies de aves, sons, diferentes culturas e contextos locais, portanto, é necessário estudar as áreas rurais e urbanas. Além disso, a pesquisa é necessária em crianças e adolescentes que têm sido muito pouco representados. Finalmente, é necessário ter mais informações dos países latino-americanos, pois eles representam as mais diversas espécies de aves e poder comparar com regiões mais estudadas como a Europa e a América do Norte

Treatment of Social Media in Person Name Disambiguation in the Web

En este trabajo presentamos dos heurísticas para tratar páginas web correspondientes a redes sociales en el problema de desambiguación de nombres de persona en la Web. Este problema consiste en agrupar las páginas web proporcionadas por un motor de búsqueda al consultar un nombre de persona según el individuo al que se refieren. Aunque estas páginas web pueden afectar negativamente en la agrupación de los resultados, la mayoría de sistemas del estado del arte no tienen en cuenta su papel en este problema. Hemos evaluado nuestras heurísticas con dos colecciones que contienen este tipo de páginas web. Para agrupar las páginas web hemos utilizado una extensión de un algoritmo del estado del arte. Ambas heurísticas obtienen mejoras cuando hay un número elevado de páginas sociales y el algoritmo propuesto es más independiente del nivel de ambigüedad de los nombres de persona que otros propuestos por el estado del arte.In this work, we present two heuristics to treat web pages from social networks for person name disambiguation in the Web. This problem consists in clustering the results provided by a search engine when the query is a person name according to the individual they refer to. Although these web pages could negatively affect when grouping the results, most of the systems in the state-of-the-art do not take into account their role in this problem. We have evaluated our heuristics with two collections that contain this kind of web pages. We have used an extension of an algorithm of the state of the art to cluster the web pages. Both heuristics get improvements when there is a high number of social web pages, and the proposed algorithm is more independent with respect to the ambiguity degree of person names than other ones in the state of the art.Este trabajo ha sido subvencionado por el Ministerio de Ciencia e Innovación [MED-RECORD Project, TIN2013-46616-C2-2-R] y el grupo CVIP de la URJC

Función del área de gestión humana en el proceso de adaptación ante los cambios organizacionales derivados de la pandemia percibida por un grupo de trabajadores del sector minero en Colombia

Objetivo. Analizar la función del área de gestión humana en el proceso de adaptación ante los cambios organizacionales derivados de la pandemia del Covid-19 percibida por un grupo de trabajadores del sector minero en Colombia. Método. Se realizó un estudio cualitativo descriptivo de corte transversal; el diseño de la investigación fue un estudio de caso basado en entrevistas semiestructuradas a diez (10) empleados con mínimo dos (2) años de servicio. Resultado. Los datos obtenidos nos permitieron comprender la función de gestión humana en el proceso de adaptación de los empleados, su aporte fundamental para facilitar la implementación de estrategias, medidas y acciones orientadas a mitigar este impacto inesperado del Covid-19 en las empresas mineras en Colombia. Se demuestra que gestión humana como socio estratégico ayudó a el cumplimiento e implementación de las medidas corporativas en los empleados. Conclusión. Se evidenció que no solo los países no estaban preparados para esta pandemia, las organizaciones no fueron ajena a este impacto, y las empresas mineras quienes mantienen implementado un sistema de controles de seguridad para poder tener la dinámica operativa de sus procesos, si bien los empleados perciben que gestión humana fue importante en el proceso de adaptación, los empleados han notado la disminución del liderazgo de gestión humana una vez alcanzada la etapa de implementación, están manifestando sentirse solos en la parte final si se pudiese decir del proceso de adaptación ante los cambios organizacionales originados por la pandemia del Covid-19.Objective. Analyze the role of the human management area in the process of adaptation to the organizational changes derived from the Covid-19 pandemic perceived by a group of workers in the mining sector in Colombia. Method. A qualitative descriptive cross-sectional study was carried out; The research design was a case study based on semi-structured interviews with ten (10) employees with a minimum of two (2) years of service. Outcome. The data obtained allowed us to understand the human management function in the employee adaptation process, its fundamental contribution to facilitate the implementation of strategies, measures and actions aimed at mitigating this unexpected impact of Covid-19 in mining companies in Colombia. It is shown that human management as a strategic partner helped the compliance and implementation of corporate measures in employees. Conclusion. It was evidenced that not only the countries were not prepared for this pandemic, the organizations were not oblivious to this impact, and the mining companies who maintain a system of security controls in place in order to have the operational dynamics of their processes, although the employees They perceive that human management was important in the adaptation process, employees have noticed the decrease in human management leadership once the implementation stage has been reached, they are manifesting that they feel alone in the final part if it could be said of the adaptation process in the face of changes organizational problems caused by the Covid-19 pandemic

On using the minimum energy dissipation to estimate the steady-state of a flow network and discussion about the resulting power-law:application to tree-shaped networks in HVAC systems

[EN] The paper analyses how to compute the steady-state flow distribution through a given network by using the Minimum Entropy Production (MinEP) principle. For isothermal and incompressible flows, this is equivalent to the minimal dissipation of energy. The conditions that make this method equivalent to the conventional one are studied. There must exist a power-law for the energy dissipation (entropy generation) where the exponent must be the same for the whole network. To our knowledge, Niven was the first to get to this result. However he applied MinEP only to parallel pipes and unfortunately discarded it as a general method. The paper shows why it cannot be discarded yet. We discuss the role of the chosen exponent m and its link to the underlying physical phenomena. Moreover it is shown that there is a ¿hidden¿ fixed point value problem that must be studied further. The method introduced in this paper is developed specially for tree-shaped duct-networks which are frequently encountered in HVAC (Heating Ventilation and Air Conditioning) systems. The paper explains briefly what triggered this research; specifically, difficulties related with branched junctions, mainly in return-type networks.Soto Francés, VM.; Pinazo Ojer, JM.; Sarabia Escrivà, EJ.; Martínez, PJ. (2019). On using the minimum energy dissipation to estimate the steady-state of a flow network and discussion about the resulting power-law:application to tree-shaped networks in HVAC systems. Energy. 172:181-195. https://doi.org/10.1016/j.energy.2019.01.060S18119517

About using the minimum energy dissipation to find the steady-state flow distribution in networks

[EN] The incorrect analysis of the flow distribution through HVACduct-networks has an economical and environmental impact.The existence ofnegativehead loss coefficients at branched junc-tions poses a difficulty. However the dissipated energy is inher-ently positive and simplifies the solution. The paper exploresthe use of a variational method based on the minimization of thedissipated mechanical energy to find the actual steady-state flowdistribution through a network. To our knowledge, Robert Nivenwas the first to propose/explore this idea but unfortunately dis-carded the method. The paper begins with a short explanation,afterwards extends previous outcomes [1] and ends with an ex-ampleSoto Francés, VM.; Pinazo Ojer, JM.; Sarabia Escrivà, EJ.; Martínez-Beltrán, P. (2019). About using the minimum energy dissipation to find the steady-state flow distribution in networks. Taylor Francis. 1-6. http://hdl.handle.net/10251/1905161

Preliminary Study of the Automatic Annotation of Hospital Discharge Report with ICD-10 codes

En la actualidad, la cantidad de recursos que se destinan a la codificación de informes médicos es enorme. Con la reciente implantación del estándar CIE-10 en el sistema sanitario español se acrecientan las dificultades, ya que se incrementa el número de posibles códigos CIE por cada informe, disponiendo de una escasa cantidad de datos generados y codificados. En este artículo se describen los retos que plantea esta tarea y se propone una primera aproximación de combinación de técnicas para implantar un sistema capaz de, dado un informe, recomendar automáticamente códigos CIE-10 a los codificadores.Nowadays, the amount of resources dedicated to encode medical reports is huge. In spite of this, an automatic solution for annotation does not appear to be consolidated. With the recent implantation of the CIE-10 standard, encoding becomes increasingly complex, since the number of possible CIE codes for each report is increased and at the same time a minimal quantity of generated and encoded data is avaliable. In this paper, it is described the challenges posed by this task and proposed a first combination of techniques for implementing a system capable of automatically assisting coding specialists by recommending CIE-10 codes regarding a medical report.Este trabajo ha sido financiado por el Ministerio de Ciencia e Innovación a través del proyecto PROSA-MED: TIN2016-77820-C3