Automating decision making to help establish norm-based regulations

Norms have been extensively proposed as coordination mechanisms for both agent and human societies. Nevertheless, choosing the norms to regulate a society is by no means straightforward. The reasons are twofold. First, the norms to choose from may not be independent (i.e, they can be related to each other). Second, different preference criteria may be applied when choosing the norms to enact. This paper advances the state of the art by modeling a series of decision-making problems that regulation authorities confront when choosing the policies to establish. In order to do so, we first identify three different norm relationships -namely, generalisation, exclusivity, and substitutability- and we then consider norm representation power, cost, and associated moral values as alternative preference criteria. Thereafter, we show that the decision-making problems faced by policy makers can be encoded as linear programs, and hence solved with the aid of state-of-the-art solvers

Online Automated Synthesis of Compact Normative Systems

Peer reviewedPostprin

Computation of the Distribution of the Absorption Time of the Drifted Diffusion with Stochastic Resetting and Mixed Boundary Conditions

This article introduces two techniques for computing the distribution of the first passage or absorption time of a drifted Wiener diffusion with Poisson resetting times, in presence of an upper hard wall reflection and a lower absorbing barrier. The first method starts with the Pad\'e approximation to the Laplace transform of the first passage time, which is then inverted through the partial fraction decomposition. The second method, which we call "multiresolution algorithm", is a Monte Carlo technique that exploits the properties of the Wiener process in order to generate Brownian bridges at increasing resolution levels. This technique allows to approximate the first passage time at any level of accuracy. An intensive numerical study reveals that the multiresolution algorithm has higher accuracy than standard Monte Carlo, whereas the faster method based on the Pad\'e approximation provides sufficient accuracy in specific circumstances only. Besides these two numerical approximations, this article provides a closed-form expression for the expected first passage time

Mediation Role of Physical Fitness and Its Components on the Association Between Distribution-Related Fat Indicators and Adolescents' Cognitive Performance: Exploring the Influence of School Vulnerability. The Cogni-Action Project

Background: Physical fitness and fatness converge simultaneously modulating cognitive skills, which in turn, are associated with children and adolescents' socioeconomic background. However, both fitness components and fat mass localization are crucial for understanding its implication at the cognitive level. Objective: This study aimed to determine the mediation role of a global physical fitness score and its components on the association between different fatness indicators related to fat distribution and adolescents' cognitive performance, and simultaneously explore the influence of school vulnerability. Methods: In this study, 1,196 Chilean adolescents participated (aged 10-14; 50.7% boys). Cardiorespiratory fitness (CRF), muscular fitness (MF), and speed-agility fitness (SAF) were evaluated, and a global fitness score (GFS) was computed adjusted for age and sex (CRF + MF + SAF z-scores). Body mass index z-score (BMIz), sum-of-4-skinfolds (4SKF), and waist-to-height ratio (WHtR) were used as non-specific, peripheral, and central adiposity indicators, respectively. A global cognitive score was computed based on eight tasks, and the school vulnerability index (SVI) was registered as high, mid or low. A total of 24 mediation analyses were performed according to two models, adjusted for sex and peak high velocity (Model 1), and adding the school vulnerability index (SVI) in Model 2. The significance level was set at p < 0.05. Results: The fitness mediation role was different concerning the fatness indicators related to fat distribution analyzed. Even after controlling for SVI, CRF (22%), and SAF (29%), but not MF, mediated the association between BMIz and cognitive performance. Likewise, CRF, SAF and GFS, but not MF, mediated the association between WHtR and cognitive performance (38.6%, 31.9%, and 54.8%, respectively). No mediations were observed for 4SKF. Conclusion: The negative association between fatness and cognitive performance is mitigated by the level of adolescents' physical fitness, mainly CRF and SAF. This mediation role seems to be more consistent with a central fat indicator even in the presence of school vulnerability. Strategies promoting physical fitness would reduce the cognitive gap in children and adolescents related to obesity and school vulnerability.The ``Cogni-Action Project'' was supported by the National Commission for Scientific and Technological Research CONICYT/FONDECYT INICIACION 2016 grant no. 11160703. IE-C was supported by the Spanish Ministry of Science and Innovation (RYC2019-027287-I)

Electrically-driven amplification of terahertz acoustic waves in graphene

In graphene devices, the electronic drift velocity can easily exceed the speed of sound in the material at moderate current biases. Under this condition, the electronic system can efficiently amplify acoustic phonons, leading to the exponential growth of sound waves in the direction of the carrier flow. Here, we demonstrate that such phonon amplification can significantly modify the electrical properties of graphene devices. We observe a super-linear growth of the resistivity in the direction of the carrier flow when the drift velocity exceeds the speed of sound, causing up to a 7 times increase over 8 micrometers. The resistance growth is observable for carrier densities away from the Dirac point and is enhanced at cryogenic temperatures. These observations are explained by a theoretical model for the electrical-amplification of acoustic phonons, which reach frequencies up to 2.2 terahertz with the nanoscale wavelength set by gate-tunable ~kF transitions across the Fermi surface. These findings offer a route to high-frequency on-chip sound generation and detection, which can be used to modulate and probe electronic physics in van der Waals heterostructures in the terahertz frequency range

Caracterización estructural, térmica y morfológica de Crescentia cujete (totumo) con potencial uso como polímero biodegradable

Actualmente, se reconoce que los plásticos derivados de productos petroquímicos son uno de los mayores problemas sociales y ambientales, debido al uso excesivo y a la dificultad de su descomposición, lo que ha aumentado la preocupación por encontrar alternativas a estos materiales. De esta forma, este trabajo se centra en la caracterización por medio de DRX, FRX FTIR, DSC, TGA y análisis cualitativo de biodegradabilidad del fruto de Crescentia cujete (totumo), a fin de establecer bases para ser considerado una alternativa de uso, como polímero biodegradable. Los resultados de la caracterización estructural evidenciaron que se trata de un material semicristalino, compuesto, principalmente, de celulosa tipo I, con una cristalinidad del 29 %. Se determinó que la estabilidad térmica de este material alcanza los 175 °C, con la pérdida de humedad, siendo la única observación hasta esta temperatura. Se confirmó la presencia de hemicelulosa y celulosa a temperaturas superiores y su posterior descomposición. El estudio de biodegradabilidad indicó la presencia de un ataque microbiano a las 72 horas de monitoreo, evidenciado por la aparición de un hongo en la superficie del material, lo que causó cambios en la emisión de dióxido de carbono y monóxido de carbono. Después de 200 horas se observó una disminución del volumen del hongo, lo que sugiere que este se propagó al interior del material, dando origen puntos negros de descomposición en la superficie de las muestras. Así, el totumo se podría considerar como una alternativa de material lignocelulósico, para la preparación de materiales poliméricos biodegradables

Timing results using an FPGA-based TDC with large arrays of 144 SiPMs

Silicon photomultipliers (SiPMs) have become an alternative to traditional tubes due to several features. However, their implementation to form large arrays is still a challenge especially due to their relatively high intrinsic noise, depending on the chosen readout. In this contribution, two modules composed of SiPMs with an area of roughly mm mm are used in coincidence. Coincidence resolving time (CRT) results with a field-programmable gate array, in combination with a time to digital converter, are shown as a function of both the sensor bias voltage and the digitizer threshold. The dependence of the CRT on the sensor matrix temperature, the amount of SiPM active area and the crystal type is also analyzed. Measurements carried out with a crystal array of 2 mm pixel size and 10 mm height have shown time resolutions for the entire 288 SiPM two-detector set-up as good as 800 ps full width at half maximum (FWHM).This work was supported in part by the University of Valencia and the Institute for Instrumentation and Molecular Imaging.Aguilar, A.; González Martínez, AJ.; Torres, J.; García Olcina, R.; Martos, J.; Soret, J.; Conde Castellanos, PE.... (2015). Timing results using an FPGA-based TDC with large arrays of 144 SiPMs. IEEE Transactions on Nuclear Science. 62(1):12-18. doi:10.1109/TNS.2014.2359078S121862

PET detector block with accurate 4D capabilities

[EN] In this contribution, large SiPM arrays (8 x 8 elements of 6 x 6 mm(2) each) are processed with an ASIC-based readout and coupled to a monolithic LYSO crystal to explore their potential use for TOF-PET applications. The aim of this work is to study the integration of this technology in the development of clinical PET systems reaching sub-300 ps coincidence resolving time (CRT). The SiPM and readout electronics have been evaluated first, using a small size 1.6 mm (6 mm height) crystal array (32 x 32 elements). All pixels were well resolved and they exhibited an energy resolution of about 20% (using Time-over-Threshold methods) for the 511 keV photons. Several parameters have been scanned to achieve the optimum readout system performance, obtaining a CRT as good as 330 +/- 5 ps FWHM. When using a black-painted monolithic block, the spatial resolution was measured to be on average 2.6 +/- 0.5 mm, without correcting for the source size. Energy resolution appears to be slightly above 20%. CRT measurements with the monolithic crystal detector were also carried out. Preliminary results as well as calibration methods specifically designed to improve timing performance, are being analyzed in the present manuscript.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 695536). It has also been supported by the Spanish Ministerio de Economia, Industria y Competitividad under Grants No. FIS2014-62341-EXP and TEC2016-79884-C2-1-R.Lamprou, E.; Aguilar -Talens, A.; Gonzalez-Montoro, A.; Monzó Ferrer, JM.; Cañizares-Ledo, G.; Iranzo-Egea, S.; Vidal San Sebastian, LF.... (2018). PET detector block with accurate 4D capabilities. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 912:132-136. https://doi.org/10.1016/j.nima.2017.11.002S13213691

Relación entre la fuerza prensil y los marcadores de riesgo cardiovascular en jóvenes universitarios

Introduction: cardiovascular diseases (CVD) represent a set of alterations that compromise the function of the heart and the different blood vessels that make up the cardiovascular system. Objective: to determine the relationship between prehensile strength and markers of cardiovascular risk in university students. Methods: observational, descriptive and correlational study with 159 apparently healthy university students &gt;18 years of age. Sociodemographic variables were identified with respect to sex and age. Also, we determined the weight, height, abdominal circumference, hip and waist/hip ratio, glucose levels, anxiety, depression, smoking, physical activity and sedentary levels. The Ruffier Dickson test was applied taking into account the values of heart rate, dyspnea and perceived fatigue, pre and post test, and heart rate after 1 minute after the end of the test. Results: this study was attended by 159 participants, (H:35.8% M:64.2%), where we can determine that 33.33 % of men and 50.98 % of women have a perimeter high risk abdominal and 64.91 % men and 95.09 % women a high risk hip circumference. On the other hand, the nutritional status indicates that 4.4 % of the subjects were underweight, 30.2 % were overweight and 17 % were obese. In contrast, 2.52 % of the participants had a blood pressure above the normal cuts at rest according to the AHA, and 35.2 % had fasting glucose levels above 99 mg/dl. Conclusions: there is no significant evidence between prehensile strength and markers of cardiovascular risk in the young adult population.Introducción: las enfermedades cardio-vasculares (ECV) representan un conjunto de alteraciones que comprometen la función del corazón y los diferentes vasos sanguíneos que conforman el sistema cardiovascular. Objetivo: determinar la relación entre la fuerza prensil y los marcadores de riesgo cardiovascular en jóvenes universitarios. Métodos: estudio observacional, descriptivo y correlacional con 159 estudiantes universitarios aparentemente sanos &gt;18 años de edad. Se identificaron variables socio-demográficas respecto al sexo y la edad. También se determinó peso, talla, circunferencia abdominal, cadera y la relación cintura/cadera, niveles de glucosa, ansiedad, depresión, tabaquismo, actividad física y niveles sedentarismo. Se aplicó el test de Ruffier Dickson teniendo en cuenta los valores de frecuencia cardiaca, disnea y fatiga percibida, pre y post test, y frecuencia cardiaca posterior a 1 minuto de finalizar el test. Resultados: participaron 159 participantes, (H:35,8% M: 64,2%), donde se personas, de las que el 33,33 % de los hombres y el 50,98 % de las mujeres tienen un perímetro abdominal de alto riesgo y el 64,91 % de hombres y 95,09 % de mujeres una circunferencia de cadera de alto riesgo. Por otro lado, el estado nutricional indica que el 4,4 % de los sujetos tenía infrapeso, 30,2 % sobrepeso y 17 % obesidad. En contraste, un 2,52 % de los participantes tuvieron una presión arterial por encima de los cortes normales en estado de reposo según la AHA, y 35,2 % tuvieron niveles de glucosa en ayunas por encima de 99 mg/dl. Conclusión: no existe evidencia significativa entre la fuerza prensil y los marcadores de riesgo cardiovascular en población adulta joven