Error Cascades in Observational Learning: An Experiment on the Chinos Game

The paper reports an experimental study based on a variant of the popular Chinos game, which is used as a simple but paradigmatic instance of observational learning. There are three players, arranged in sequence, each of whom wins a fixed price if she manages to guess the total number of coins lying in everybody’s hands. Our evidence shows that, despite the remarkable frequency of equilibrium outcomes, deviations from optimal play are also significant. And when such deviations occur, we find that, for any given player position, the probability of a mistake is increasing in the probability of a mistake of her predecessors. This is what we call an error cascade, which we rationalize by way of a simple model of “noisy equilibrium”.positional learning, error cascades

Los científicos en la organización y la gestión de la universidad: una visión histórica.

The models of University organization and management can be studied from very different and complementary points of view. In this article the participation of two eminent scientists are studied, namely Blas Cabrera's (Rector) and Juan Negrín's (Secretary of the Faculty of Medicine) contributions at Madrid's Central University General Council at the beginning of the thirties. The analysis fulfilled, of an essential historical character, is based upon unpublished documents, namely the Council's Libro de Actas, whose first meeting took place on the 6th of March of 1930. As a whole, the study will aloud the detection of the various approaches to University organization and management. We will show those difficulties an experimental physicist as Blas Cabrera will suffer as Rector, opposite to the impressive qualities as organiser that can be seen in a physician and politician as Juan Negrín, whom, through his role should be considered undoubtedly the Council's alma mater

Educación y sociedad en España. 1929-1931: el conflicto estudiantil en y desde la Universidad de Madrid.

Sin resume

How market power affects the behaviour of a pumped storage hydro unit in the day-ahead electricity market?

The integration of large amounts of wind energy in power systems raises important operation issues such as the balance between power demand and generation. The pumped storage hydro (PSH) units are seen as one solution for this issue, avoiding the need for wind power curtailments. However, the behavior of a PSH unit might differ considerably when it operates in a liberalized market with some degree of market power. In this regard, a new approach for the optimal daily scheduling of a PSH unit in the day-ahead electricity market was developed and presented in this paper, in which the market power is modeled by a residual inverse demand function with a variable elasticity. The results obtained show that increasing degrees of market power of the PSH unit correspond to decreasing levels of storage and, therefore, the capacity to integrate wind power is considerably reduced under these circumstances

Redes bayesianas para identificar perfiles de estudiante. Aplicación al estudio del abandono de las titulaciones de Informática en la Universidad de Castilla-La Mancha

El abandono de los estudiantes es un problema que afecta a todas las universidades siendo más acusado en las titulaciones de las ramas de Ingeniería y Arquitectura. Como docentes del Grado de Ingeniería Informática de la Universidad de Castilla-La Mancha nuestro interés se centra en analizar el perfil del estudiante que abandona estos estudios, con el fin de definir acciones orientadas a reducir la actual tasa de abandono. En ediciones anteriores de las JENUI se ha analizado esta problemática desde el punto de vista de la estadística tradicional y de la minería de datos, mediante árboles de decisión y regresión multivariante; en este trabajo lo abordamos mediante algoritmos de aprendizaje de redes bayesianas, ya que éstas tienen una semántica muy rica y son fácilmente interpretables. Los resultados del trabajo no son concluyentes debido a las restricciones de la base de datos utilizada, pero la descripción del estudio realizado pone en valor el interés de la técnica empleada y sienta las bases para mejorar el alcance de la investigación en trabajos futuros relacionados con la extración de datos de futuros estudiantes

Pooling or fooling? An experiment on signaling

We compare two zero-sum versions of the so called Chinos Game, a traditional parlour game played in many countries. In one version, which we call Preemption Scenario, the first player who guesses right wins the prize. In the alternative version, called the Copycat Scenario, the last player who guesses right wins the prize. While in the Preemption Scenario there is a unique and fully revealing equilibrium, in the Copycat Scenario all equilibria have first movers pool (i.e. hide) their private information. Our experimental evidence shows, however, that in the latter case early movers do not pool but try to fool, i.e. to “lie” by systematically distorting behavior relative to equilibrium play. In fact, doing so they benefit, although the resulting gains diminish as the game proceeds. This highlights the point that, as players adjust their behavior off equilibrium, they also attempt to exploit the induced strategic uncertainty whenever the game allows for this possibility.Financial support from the Spanish Ministry of Economic Development (ECO2014-52345-P and ECO2015-65820-P), Generalitat Valenciana (Research Projects Grupos 3/086) and Instituto Valenciano de Investigaciones Económicas (IVIE) is gratefully acknowledged

APARICIÓN TEMPRANA DEL PATRÓN DE DOLOR CRÓNICO EN PACIENTES MUSCULOESQUELÉTICOS SUBAGUDOS

The chronic pain pattern implies high levels of negative emotions, pain and perceived disability disability perceived. Up to date few studies have assessed when this chronic pain pattern appears. This study is aimed at exploring this issue. Methods: were evaluated  146 subjects with 4 weeks sick leave due to musculoskeletal diseases (MSDs) and 95 with Rheumatoid Arthritis (RA). All patients completed the following assessment instruments: the Sadness and Depression Questionnaire (CTD), Anxiety situations and responses. Inventory –Brief form- (ISRA-B), Health Assessment Questionnaire (HAQ), a visual analogy scale for intensity of pain and a likert type scale for the frequency of pain. The analyses included a comparison on the scores of the tests between patients on sick leave due to MD compared to RA patients. Descriptive and bivariate analyses were performed. Results: Patients on sick leave due to MD and RA patients reported similar perception of their disability, showing a high HAQ score mean. Patients on sick leave due to MD reported more perceived frequency and intensity of pain than RA patients. In relation to negative emotions, both groups reported similar high levels with some poorer levels for RA patients compared to patients on sick leave due to MD for cognitive, evaluation and life situations anxiety. Depression scores presented the same levels for both patients groups. Conclusions: Our study shows that patients with subacute pain/disability and chronic pain/disability report very similar pattern for negative emotions and perception of pain and disability, suggesting that these factors appear in an early stage and contributing to the transition from acute to chronic pain/disability.El patrón de dolor crónico implica altos niveles de emociones negativas, dolor y discapacidad percibida. Pocos estudios han evaluado el patrón de aparición del dolor crónico  y éste era nuestro objetivo. Método: fueron evaluados 146 participantes con 4 semanas la Baja Laboral por enfermedades musculoesqueléticas (DsMS) y 95 con artritis reumatoide (AR) mediante los siguientes instrumentos: el Cuestionario de Tristeza y Depresión (CTD), el  Inventario de Situaciones y Respuestas de Ansiedad–forma breve-. (ISRA-B), Cuestionario de Evaluación de Salud (HAQ), una escala analógica visual para la intensidad del dolor y una escala tipo Likert para la frecuencia del dolor. Los análisis (descriptivos y bivariados) incluyeron una comparación de las puntuaciones de las pruebas entre los pacientes con baja laboral por EM en comparación con los pacientes con AR.  Resultados: Los pacientes con Baja Laboral por enfermedades musculoesqueléticas y los pacientes con AR informaron de una percepción similarde su discapacidad, según el HAQ. Pacientes con Baja Laboral por enfermedades musculoesqueléticas informaron mayor frecuencia percibida y más intensidad de dolor que los pacientes con AR. En relación a las emociones negativas, ambos grupos presentaron niveles altos y similares, con algunos niveles más pobres de los pacientes con AR en comparación con Pacientes con Baja Laboral por enfermedades musculoesqueléticas para la ansiedad cognitiva, la ansiedad de evaluación y la de la vida cotidiana (en  ISRA-B). Las puntuaciones en depresión presentan los mismos niveles en ambos grupos de pacientes.Conclusión. Nuestro estudio muestra que los pacientes con dolor subagudo/discapacidad y dolor crónico/discapacidad reportan un patrón muy similar para las emociones negativas y la percepción del dolor y la discapacidad, lo que sugiere que estos factores aparecen en una etapa temprana y favorecen, por tanto, la transición de dolor agudo a crónico/discapacidad

Is the electric vehicle a solution for the wind power integration in the portuguese power system?

The integration of Plug-in electric vehicles in the transportation sector has a great potential to reduce oil dependency, the GHG emissions and to contribute for the integration of renewable sources into the electricity generation mix. Portugal has a high share of wind energy, and curtailment may occur, especially during the off-peak hours with high levels of hydro generation. In this context, the electric vehicles, seen as a distributed storage system, can help to reduce the potential wind curtailments and, therefore, increase the integration of wind power into the power system. In order to assess the energy and environmental benefits of this integration, a methodology based on a unit commitment and economic dispatch is adapted and implemented. From this methodology, the thermal generation costs, the CO2 emissions and the potential wind generation curtailment are computed. Simulation results show that a 10% penetration of electric vehicles in the Portuguese fleet would increase electrical load by 3% and reduce wind curtailment by only 26%. This results from the fact that the additional generation required to supply the electric vehicles is mostly thermal. The computed CO2 emissions of the EV are 92 g CO2/kWh which become closer to those of some new ICE engines

Aqueous phase reforming of starch wastewater over Pt and Pt-based bimetallic catalysts for green hydrogen production

This work analyses the application of aqueous phase reforming (APR) for green hydrogen production from starch industry wastewater. This work reports for the first time on the direct conversion of a high molecular weight biomass polymer contained in wastewater in contrast to low molecular weight substrates mainly reported in the literature. The potential of this type of feedstock was evaluated by varying the starch source (rice, potato, sweet potato and cassava) and the type of catalyst (carbon supported Pt, PtRu, PtPd, PtRe and PtRh catalysts). In APR experiments at 220 °C with synthetic wastewater, PtRu/C and Pt/C catalysts achieved the highest H2 yield values, around 51 mmol H2 per g of organic carbon in the initial wastewater, close to 2.6 times higher than that reported in the literature of brewery wastewater, a promising substrate. The lack of free aldehyde or keto groups due to glycosidic bonds between glucose units in starch results in higher conversion to gas and H2 production compared to APR of glucose. This fact shows that APR has more feedstock flexibility than that previously reported for light compounds. In the experiments with real wastewaters, the organic matter removal was influenced largely by the starch source: the best APR performance (28.5 mmol H2 gTOCi−1) was obtained for rice processing wastewater, which is characterized by the highest starch concentration and the lowest protein content. Poor performance was observed in the APR of potato processing wastewater, probably due to catalyst deactivation caused by protein fractio