3,237 research outputs found

    Artificial Neural Networks applied to improve low-cost air quality monitoring precision

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    It is a fact that air pollution is a major environmental health problem that affects everyone, especially in urban areas. Furthermore, the cost of high-end air pollution monitoring sensors is considerably high, so public administrations are unable to afford to place an elevated number of measuring stations, leading to the loss of information that could be very helpful. Over the last few years, a large number of low-cost sensors have been released, but its use is often problematic, due to their selectivity and precision problems. A calibration process is needed in order to solve an issue with many parameters with no clear relationship among them, which is a field of application of Machine Learning. The objectives of this project are first, integrating three low-cost air quality sensors into a Raspberry Pi and then, training an Artificial Neural Network model that improves precision in the readings made by the sensors.Es un hecho que la contaminación del aire es un gran problema para la salud a nivel mundial, especialmente en zonas urbanas. Además, el coste de los sensores de contaminación de gama alta es considerablemente alto, por lo que los organismos públicos no pueden permitirse emplazar un gran número de estaciones de medida, perdiendo información que podría ser muy útil. A lo largo de los últimos años, han surgido muchos sensores de contaminación de bajo coste, pero su uso suele ser complicado, ya que tienen problemas de selectividad y precisión. Los objetivos de este proyecto son primero integrar tres sensores de contaminación de bajo coste en una Raspberry Pi y sobre todo, entrenar un modelo basado en una red neuronal artificial que mejore la precisión de las lecturas realizadas por los sensores.Està demostrat que la contaminació de l'aire és un gran problema per a la salut a nivell mundial, especialment en zones urbanes. A més, el cost dels sensors de contaminació de gama alta és considerablement alt, motiu pel qual els organismes públics no es poden permetre emplaçar una gran quantitat d'estacions de mesura, perdent informació que podria resultar molt útil. Al llarg dels últims anys, han sorgit molts sensors de contaminació de baix cost, però el seu ús és sovint complicat, ja que tenen problemes de selectivitat i precisió. Els objectius d'aquest projecte són primer de tot integrar tres sensors de contaminació de baix cost en una Raspberry Pi i sobretot, entrenar un model basat en una xarxa neuronal artificial que millori la precisió de les lectures realitzades pels sensors

    A domain-decomposition method to implement electrostatic free boundary conditions in the radial direction for electric discharges

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    At high pressure electric discharges typically grow as thin, elongated filaments. In a numerical simulation this large aspect ratio should ideally translate into a narrow, cylindrical computational domain that envelops the discharge as closely as possible. However, the development of the discharge is driven by electrostatic interactions and, if the computational domain is not wide enough, the boundary conditions imposed to the electrostatic potential on the external boundary have a strong effect on the discharge. Most numerical codes for electric discharges circumvent this problem by either using a wide computational domain or by calculating the boundary conditions by integrating the Green's function of an infinite domain. Here we describe an accurate and efficient method to impose free boundary conditions for an elongated electric discharge. To facilitate the use of our method we provide a sample implementation.Comment: 21 pages, 4 figures, a movie and a sample code in python. A new Appendix has been adde

    Study of the immigrant population’s attitude towards organ donation in two groups from Pakistan and Morocco.

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    Organ transplantation may not be done without the awareness and active participation of the community: no donor organs, no transplants. In the past few years, Spain’s growing immigrant population has posed new challenges in this field, and calls for reflection upon the most appropriate forms of intercultural dialogue. In consideration of the very special implications of organ donation, our interest was to define, compare and contrast the values and beliefs of two groups from Pakistan and Morocco.Organ transplantation may not be done without the awareness and active participation of the community: no donor organs, no transplants. In the past few years, Spain’s growing immigrant population has posed new challenges in this field, and calls for reflection upon the most appropriate forms of intercultural dialogue. In consideration of the very special implications of organ donation, our interest was to define, compare and contrast the values and beliefs of two groups from Pakistan and Morocco.

    Malaria eradication in Mexico: Some historico-parasitological views oncold war, deadly fevers by Marcos Cueto, Ph.D

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    This review of Professor Marcos Cueto's Cold War Deadly Fevers: Malaria Eradication in Mexico, 1955–1975 discusses some of the historical, sociological, political and parasitological topics included in Dr. Cueto's superbly well-informed volume. The reviewer, a parasitologist, follows the trail illuminated by Dr. Cueto through the foundations of the malaria eradication campaign; the release in Mexico of the first postage stamp in the world dedicated to malaria control; epidemiological facts on malarial morbidity and mortality in Mexico when the campaign began; the emergence of problem areas that impeded eradication; considerations on mosquitoes and malaria transmission in Mexico; the role of business and society in malaria eradication; the results of the campaign; the relationship between malaria and poverty; and the parasitological lessons to be learned from the history of malaria eradication campaigns. Dr. Cueto's excellent and well-informed exploration of malaria – not merely as a disease but as a social, economic and human problem – makes this book required reading

    Development of hip dysplasia in hereditary multiple exostosis

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    In approximately 25% of patients with hereditary multiple exostosis, there is an abnormal osteochondral formation localized in the femoral proximal metaphysis. This formation often causes a mechanically progressive insufficiency of the acetabular cavity, a true developmental hip dysplasia, that together with a coxa valga deformity, which is also present, causes a gradual deterioration in the relations of this joint. This malformation has a poor prognosis and is difficult to manage. Although this entity is rather frequent and quite severe, it is rarely found in the medical literature. The author describes six private cases, taken from a total of 24,000 patients (0.25/1000) as examples of this entity, and provides a review of the literature

    Activitat física, exercici físic o esport: què estem fent?

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