Numerical solution and bifurcation analysis of nonlinear partial differential equations with extreme learning machines

We address a new numerical method based on a class of machine learning methods, the so-called Extreme Learning Machines (ELM) with both sigmoidal and radial-basis functions, for the computation of steady-state solutions and the construction of (one-dimensional) bifurcation diagrams of nonlinear partial differential equations (PDEs). For our illustrations, we considered two benchmark problems, namely (a) the one-dimensional viscous Burgers with both homogeneous (Dirichlet) and non-homogeneous boundary conditions, and, (b) the one- and two-dimensional Liouville–Bratu–Gelfand PDEs with homogeneous Dirichlet boundary conditions. For the one-dimensional Burgers and Bratu PDEs, exact analytical solutions are available and used for comparison purposes against the numerical derived solutions. Furthermore, the numerical efficiency (in terms of numerical accuracy, size of the grid and execution times) of the proposed numerical machine-learning method is compared against central finite differences (FD) and Galerkin weighted-residuals finite-element (FEM) methods. We show that the proposed numerical machine learning method outperforms in terms of numerical accuracy both FD and FEM methods for medium to large sized grids, while provides equivalent results with the FEM for low to medium sized grids; both methods (ELM and FEM) outperform the FD scheme. Furthermore, the computational times required with the proposed machine learning scheme were comparable and in particular slightly smaller than the ones required with FE

Innovative composite materials with enhanced acoustic, thermal, and optical performance for urban pavements: experimental characterization

Over the last decades, the implementation of innovative multifunctional materials for urban surfaces has produced a variety of paving solutions characterized by self-cleaning, self-healing, electricity conductive, solar reflective, sound absorbent properties and so on. Therefore, a key challenge is nowadays represented by the need for combining multi-physics properties in a single material or system for flooring. The present work concerns the development of a new outdoor paving application with enhanced acoustic, thermal, and optical performance. To this aim, eleven concrete mix-designs were tested. The composites were characterized by different aggregate size, material and additives. The aggregates included in the composite consist of (i) natural stones with different grain size s, (ii) expanded clay aggregates, and (iii) glass fragments. Acoustic, thermal, and optical measurements were performed for each sample. Additionally, a dedicated in-field monitoring campaign was carried out to characterize the albedo under summer boundary conditions. Finally, the thermal behaviour of the samples was tested in an environmental chamber using controlled boundary conditions in terms of temperature, humidity, and radiation. The results demonstrate that bigger grain size presents the best acoustic performance in terms of absorption capability, i.e. absorption coefficient of about 0.9 and 0.8 at 1000 Hz and 500 Hz, respectively. Moreover, the thermal-optical lab and field tests confirm previous literature result s demonstrating that the mix-design with the smaller grain size has the best reflectivity potential

Model Based Risk Assessment of Procedures and Systems for Aircraft Trajectory Management

International audienceModern Air Traffic Management (ATM) concepts of operation require a strong interaction between agents such as human operators (pilots, air traffic controllers) and information technology systems (either on-ground or on-board). Although risks shall jointly be managed by all these agents, current risk assessment techniques are usually dedicated to only one class ofagents (either human operators or IT systems). This paper addresses this issue. It proposes to extend Model Based Safety Assessment (MBSA) techniques originally developed to assess complex systems. This MBSA extension enables to assess how risk can be jointly managed by procedures and systems. The paper shows the methodology used and it presents lessons learnt from an aircraft trajectory management case study

El derecho a la educación superior y la virtualidad

Este trabajo pretende e invita a analizar la Educación Superior y la virtualidad desde una perspectiva de Derechos Humanos. Surge a partir de un seminario: “Educación en Derechos Humanos, Pedagogías de formación en derechos humanos en el nivel superior del sistema educativo”, dictado en la Universidad Nacional de Santiago del Estero y organizado por el Área y de la Cátedra libre de Derechos Humanos. En el último tramo de esta formación se elaboró una pieza didáctica con perspectiva en Derechos Humanos en pareja pedagógica. A partir de la misma, se desarrollará el material para trabajar en los talleres con perspectiva de Derechos Humanos para aspirantes al ingreso universitario a Carreras de Grado en la UNSE del año 2023. La importancia que ha adquirido la educación online en el 2020 es un hecho sin precedentes que marcó un antes y un después en las prácticas pedagógicas y en los sistemas educativos actuales a nivel global. Asimismo, se ha puesto en evidencia las desigualdades sociales, culturales y económicas.Universidad Nacional de La Plat

Sustainable New Brick and Thermo-Acoustic Insulation Panel from Mineralization of Stranded Driftwood Residues

There is considerable interest recently in by-products for application in green buildings. These materials are widely used as building envelope insulators or blocks. In this study, an experimental study was conducted to test stranded driftwood residues as raw material for possible thermo-acoustic insulation panel and environmentally sustainable brick. The thermal and acoustic characteristics of such a natural by-product were examined. Part of samples were mineralized by means of cement-based additive to reinforce the material and enhance its durability as well as fire resistance. Several mixtures with different sizes of ground wood chips and different quantities of cement were investigated. The thermo-acoustic in-lab characterization was aimed at investigating the thermal conductivity, thermal diffusivity, volumetric specific heat, and acoustic transmission loss. All samples were tested before and after mineralization. Results from this study indicate that it is possible to use stranded driftwood residues as building materials with competitive thermo-acoustic properties. In fact, the thermal conductivity was shown to be always around 0.07 W/mK in the unbound samples, and around double that value for the mineralized samples, which present a much higher volumetric specific heat (1.6 MJ/m3K) and transmission loss capability. The lignin powder showed a sort of intermediate behavior between the unbound and the mineralized samples.The authors would like to thank Gabriele Franceschetti and CVR s.r.l. for assisting the mineralization procedure of the samples. Anna Laura Pisello’s acknowledgments are due to the “CIRIAF program for UNESCO” in the framework of the UNESCO Chair “Water Resources Management and Culture”, for supporting her research. The research was founded by the Italian Environmental Ministry with an agreement entitled “Recovery and energy valorization of stranded driftwood residues” in 2014–2016. The research team leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 657466 (INPATH–TES) and No. 678407 (ZERO-PLUS)

Cardiac resynchronization therapy after coronary sinus lead extraction: feasibility and mid-term outcome of transvenous reimplantation in a tertiary referral centre

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Legionella control in the water system of antiquated hospital buildings by shock and continuous hyperchlorination: 5 years experience

To control the presence of Legionella in an old hospital water system, an integrated strategy of water disinfection-filtration was implemented in the university hospital Umberto I in Rome. Due to antiquated buildings, hospital water system design and hospital extension (38 buildings), shock hyperchlorination (sodium hypochlorite, 20-50 ppm of free chlorine at distal points for 1-2 h) followed by continuous hyperchlorination (0.5-1.0 mg/L at distal points) were adopted, and microbiological and chemical monitoring of the water supply was carried out in the university hospital (December 2006-December 2011). Overall, 1308 samples of cold 45°C (17.8%) water were collected, determining residual free chlorine (0.43 ± 0.44 mg/L), pH (7.43 ± 0.29) and trihalomethanes (8.97 ± 18.56 μg/L). Legionella was isolated in 102 (9.8%) out of 1.041 water samples without filters (L. pneumophila sg 1 17.6%, L. pneumophila sg 2-14 28.4%, L. non pneumophila 53.9%), and in none of the 267 samples with filters. Legionella was recovered in 23 buildings out of 38 and 29 samples (28.4%) exceeded 103 cfu/L. When considering the disinfection treatment Legionella was isolated: before shock hyperchlorination (21.1%), 15 days after shock hyperchlorination (7.8%), 30 days after shock hyperchlorination (3.5%), during continuous hyperchlorination (5.5%) and without continuous hyperchlorination (27.3%). Continuous hyperchlorination following the shock treatment achieved >70% reduction of positive samples, whereas no continuous hyperchlorination after shock treatment was more frequently associated to Legionella isolation (OR 6.41; 95% CI 3.10-13.26; p 0.5 < 1.0 mg/L) deteriorated water quality (organoleptic and chemical). However, shock and continuous hyperchlorination remains a valid-term option in old buildings with no water system rational design, managing problems due to hospital extension and absence of a proper hot water recirculation system

Los talleres de derechos humanos para aspirantes a carreras de grado en la Universidad Nacional de Santiago del Estero: una propuesta multidisciplinar con perspectiva ético-política año 2022

La inclusión de la perspectiva de Derechos Humanos en la formación de los aspirantes a ingresar a Carreras de Grado Universitario en las cinco Facultades de la UNSE, propuesta de la Cátedra Libre de DDHH de la Facultad de Humanidades, Ciencias Sociales y de la Salud (FHCyS) y del Área de DDHH; elaborada por la Lic. Esp. Gladys Loys y aprobada por resolución del Consejo Superior N° 357/19 inició en el año 2019. La metodología de enseñanza-aprendizaje utilizada ha sido el Taller y fue llevado a cabo por parejas pedagógicas. Este año, el grupo de Talleristas especificó en el diseño de la propuesta, la formulación epistemológica de casos disciplinares con perspectiva de derechos humanos; tomó parte del desarrollo y evaluación de la propuesta.Universidad Nacional de La Plat

Incidentes e eventos adversos no transporte intra-hospitalar em terapia intensiva

Objetivo: identificar os incidentes e eventos adversos no transporte intra-hospitalar em terapia intensiva. Método: estudo descritivo, prospectivo, quantitativo, cuja coleta de dados ocorreu com 103 transportes e envolvendo 100 profissionais de saúde que atuavam em uma unidade de terapia intensiva de um hospital público. Os dados foram obtidos por meio de um roteiro de observação e analisados descritivamente. Resultados: a maioria dos incidentes encontrados foi com equipamentos e os eventos adversos observados foram relativos às alterações fisiológicas. Conclusão: o transporte intra-hospitalar é considerado um procedimento de risco para o paciente, cujas complicações podem ser minimizadas com a elaboração de protocolos institucionais e de capacitações da equipe para realização de um transporte seguro