Evaluación del potencial de creatividad matemática en el diseño de una c-unidad

Este trabajo se centra en el proceso de diseño y evaluación de unidades didácticas que se proponen promover el pensamiento matemático creativo (PMC), las denominadas c-unidades. Dicho diseño, en manos de un grupo mixto de diseñadores, es seguido por la evaluación del potencial que estas c-unidades presentan en promover la creatividad matemática en sus futuras experimentaciones. En este trabajo nos centramos en presentar las principales herramientas usadas para realizar dicha evaluación y, centrándonos en el caso del diseño de una c-unidad sobre un estudio inter-disciplinar de historia-arqueología y matemáticas, ejemplificaremos algunos de los criterios considerados en su diseño, del producto final generado y del proceso de evaluación sobre su potencial creativo y los resultados generados

Broadcasting scalable video with generalized spatial modulation in cellular networks

This paper considers the transmission of scalable video via broadcast and multicast to increase spectral and energy efficiency in cellular networks. To address this problem, we study the use of generalized spatial modulation (GSM) combined with non-orthogonal hierarchical M-QAM modulations due to the capability to exploit the potential gains of large scale antenna systems and achieve high spectral and energy efficiencies. We introduce the basic idea of broadcasting/multicasting scalable video associated to GSM, and discuss the key limitations. Non-uniform hierarchical QAM constellations are used for broadcasting/multicasting scalable video while user specific messages are carried implicitly on the indexes of the active transmit antennas combinations. To deal with multiple video and dedicated user streams multiplexed on the same transmission, an iterative receiver with reduced complexity is described. 5G New Radio (NR) based link and system level results are presented. Two different ways of quadruplicating the number of broadcasting programs are evaluated and compared. Performance results show that the proposed GSM scheme is capable of achieving flexibility and energy efficiency gain over conventional multiple input multiple output (MIMO) schemes.info:eu-repo/semantics/publishedVersio

Statistical model of signal strength imbalance between RF channels in DTT network

Proposed is a model for the received signal strength imbalance between radio frequency (RF) channels in the UHF band. The model is fitted to field measurements carried out in the commercial DVB-T (digital terrestrial broadcasting) network of Sweden. Analysis of the measurement data reveals large differences in the received signal strength between channels according to the reception scenario and the frequency spacing. The model presented is a valuable tool to investigate the potential network planning gains of time-frequency slicing, a technique that was described in the DVB-T2 standard and that will be included in the future DVB-NGH (next generation handheld) standard for improved frequency diversity. © 2012 The Institution of Engineering and Technology.Gimenez Gandia, JJ.; Gozálvez Serrano, D.; Gómez Barquero, D.; Cardona Marcet, N. (2012). Statistical model of signal strength imbalance between RF channels in DTT network. Electronics Letters. 48(12):731-732. doi:10.1049/el.2012.1431S7317324812‘Frequency and Network Planning Aspects of DVB-T2’, May, 2011Digital Video Broadcasting (DVB); Frame structure, channel coding and modulation for a second generation digital terrestrial television broadcasting system (DVB-T2), ETSI Std. EN 302 755, V2.1.2, February 2011Gudmundson, M. (1991). Correlation model for shadow fading in mobile radio systems. Electronics Letters, 27(23), 2145. doi:10.1049/el:1991132

Water chemistry and soil radon survey at the Poas volcano (Costa Rica)

Radon-in-soil monitoring at the Poas volcano (Costa Rica) has been performed together with water chemistry from the hot crater lake since 1981 and 1983 respectively. The results are discussed as a function of the eruptive evolution of the volcano over a 13 years period (1981-1994). It is shown that no definitely clear precursory radon signals have been recorded. On the contrary, ionic species concentrations are likely to be considered good precursors, together with the temperature variations of the crater lake water

Increasing particle concentration enhances particle penetration depth but slows down liquid imbibition in thin fibrous filters

The transport of particles within thin, porous media is a complex process which received growing attention due to its applications in filtration, printing and microfluidics devices. The effect of particles on liquid imbibition and particle clogging can reduce the performance and lifetime of these applications. However, these processes are still not clearly understood and are challenging to investigate. The goal of this study is to increase our understanding about the effect of particle concentration on the imbibition process in thin fibrous membrane filters. In this study, an Ultra-Fast Imaging NMR method is used to study the particle penetration inside nylon membrane filters for particle suspensions with varying particle concentrations (C0). The measurements revealed that increasing the particle concentration increases the particle penetration depth S(t) as governed by a Langmuir isotherm given by S(t)=l(t)(1+κC0)/1+κ(C0+Cb,m), with Cb,m the bound particles and κ the binding constant. Secondly, in droplet penetration, particles slow down liquid penetration in a Darcy like manner where effect on viscosity (η) and surface tension (σ) determine the penetration speed rather than changes within permeability (K0). The final liquid front (l), scaled according to l2∝σt/η. The particle penetration depths were verified using scanning electron microscopy images.</p

Magnetite-latex nanoparticle motion during capillary uptake in thin, porous layers studied with UFI‐NMR

The transport of nanoparticles in porous media has received growing attention in the last decades due to environmental concerns in, for example, the printing industry, filtration, and transport of pollutants. Experimental studies on the imbibition of particle dispersions in porous media with sufficiently high spatial and temporal resolution are still challenging. This study shows how Ultra-Fast Imaging (UFI) NMR is an ideal tool for studying Fe3O4-latex particles penetration with a temporal resolution of 15 ms and spatial resolution of 18 µm. In the first part, it is shown that a calibration curve between the UFI‐NMR signal intensity and the particle concentration exists. In the second part, UFI‐NMR is used to study the penetration of a particles inside a thin nylon membrane during capillary uptake, which revealed liquid-particle front splitting and an inhomogeneous buildup of the particle concentration. Both the liquid-particle front splitting and inhomogeneous build up could be verified by Scanning Electron Microscopy. Our method allows to determine particle concentration profiles during capillary uptake within thin, porous media. Therefore, the technique can be easily extended to study particle penetrations in a wide variety of systems such thin interfaces, biomaterials, films, and filter media.</p

Un Recorrido de Estudio e Investigación sobre la comparación de realidad y previsión de la evolución de los usuarios de Facebook

La problemática que aborda este trabajo se centra en la búsqueda de dispositivos didácticos para una enseñanza funcional de la matemática basada en la modelización. Presentaremos el diseño de un recorrido de estudio e investigación sobre la comparación entre realidad y previsión de los usuarios de Facebook. Dicho diseño se realizará a través de una plataforma virtual en el marco del proyecto europeo MCSquared cuya implementación ha sido desarrollada con un primer curso de ciencias empresariales

Non-invasive clinical and microscopic evaluation of the response to treatment with clobetasol cream vs. calcipotriol/betamethasone dipropionate foam in mild to moderate plaque psoriasis : an investigator-initiated, phase IV, unicentric, open, randomized clinical trial

Treatment response for psoriasis is typically evaluated using clinical scores. However, patients can relapse after clinical clearance, suggesting persistent inflammation. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) can non-invasively improve treatment response assessment. To compare the clinical and non-invasive microscopic features in a psoriatic target lesion treated with clobetasol cream or calcipotriol/betamethasone dipropionate foam (Cal/BD foam). Prospective, unicentric, open, randomized clinical trial comparing clinical data [total clinical score (TCS)] and microscopic data (dermoscopy, RCM and OCT) in psoriasis patients treated with clobetasol or Cal/BD foam. We included 36 adult patients (22 men). At week 4, more patients treated with Cal/BD foam achieved TCS ≤1 than with clobetasol (63.2% vs. 18.8%, P = 0.016). Treatment satisfaction was higher with Cal/BD foam (P < 0.03). Microscopically, Cal/BD foam induced more reduction in epidermal thickness at week 4 (P < 0.049). Dilated horizontal blood vessels were more common with clobetasol than with Cal/BD foam at week 8 (69.2% vs. 31.2%, P = 0.159). If epidermal hyperplasia was noted at baseline, the response was poorer with clobetasol (P = 0.029). Small sample size, open study, imaging sampling bias. Cal/BD foam is more effective than clobetasol, has better patient satisfaction and induces greater reduction in the hyperkeratosis/acanthosis, regardless of baseline epidermal hyperplasia

Global and regional cortical thinning in first-episode psychosis patients: relationships with clinical and cognitive features

BackgroundThe thickness of the cortical mantle is a sensitive measure for identifying alterations in cortical structure. We aimed to explore whether first episode schizophrenia patients already show a significant cortical thinning and whether cortical thickness anomalies may significantly influence clinical and cognitive features.MethodWe investigated regional changes in cortical thickness in a large and heterogeneous sample of schizophrenia spectrum patients (n=142) at their first break of the illness and healthy controls (n=83). Magnetic resonance imaging brain scans (1.5 T) were obtained and images were analyzed by using BRAINS2. The contribution of sociodemographic, cognitive and clinical characterictics was investigated.ResultsPatients showed a significant total cortical thinning (F=17.55, d=−0.62, p0.53). No significant group × gender interactions were observed (all p’s>0.15). There were no significant associations between the clinical and pre-morbid variables and cortical thickness measurements (all r’s<0.12). A weak significant negative correlation between attention and total (r=−0.24, p=0.021) and parietal cortical thickness (r=−0.27, p=0.009) was found in patients (thicker cortex was associated with lower attention). Our data revealed a similar pattern of cortical thickness changes related to age in patients and controls.ConclusionsCortical thinning is independent of gender, age, age of onset and duration of the illness and does not seem to significantly influence clinical and functional symptomatology. These findings support a primary neuro-development disorder affecting the normal cerebral cortex development in schizophrenia