Valoraciones de estudiantes de las especialidades de ciencias del Máster en Profesorado de Educación Secundaria sobre el uso de actividades de juego de rol

Se analizan las valoraciones de profesorado de ciencias en formación inicial (PFI) sobre el uso de actividades de juego de rol, después de un programa formativo en el que se incluía este tipo de actividades. Los datos, aportados por 28 PFI de las especialidades de Biología y Geología y de Física y Química, se analizaron utilizando la metodología de análisis del contenido. Los resultados muestran una acogida muy positiva al uso de juegos de rol en la enseñanza de las ciencias y un amplio repertorio de valoraciones categorizadas en siete tipos, destancando las ventajas educativas, la importancia y dificultad del diseño, así como las limitaciones, inconvenientes y exigencias que conlleva su uso

Spectrum-Based Fault Localization in Model Transformations

Model transformations play a cornerstone role in Model-Driven Engineering (MDE), as they provide the essential mechanisms for manipulating and transforming models. The correctness of software built using MDE techniques greatly relies on the correctness of model transformations. However, it is challenging and error prone to debug them, and the situation gets more critical as the size and complexity of model transformations grow, where manual debugging is no longer possible. Spectrum-Based Fault Localization (SBFL) uses the results of test cases and their corresponding code coverage information to estimate the likelihood of each program component (e.g., statements) of being faulty. In this article we present an approach to apply SBFL for locating the faulty rules in model transformations. We evaluate the feasibility and accuracy of the approach by comparing the effectiveness of 18 different stateof- the-art SBFL techniques at locating faults in model transformations. Evaluation results revealed that the best techniques, namely Kulcynski2, Mountford, Ochiai, and Zoltar, lead the debugger to inspect a maximum of three rules to locate the bug in around 74% of the cases. Furthermore, we compare our approach with a static approach for fault localization in model transformations, observing a clear superiority of the proposed SBFL-based method.Comisión Interministerial de Ciencia y Tecnología TIN2015-70560-RJunta de Andalucía P12-TIC-186

Stakeholders influence on managers' environmental behaviors

La importancia del medioambiente ha aumentado tanto en teoría como en práctica en los últimos años. Los “stakeholders” – empleados, proveedores, accionistas, gobiernos, organizaciones no gubernamentales – han jugado un papel fundamental en la modificación del rol de la empresa respecto al medio ambiente. Los investigadores sugieren que la importancia de un “stakeholder” es la suma de su poder, legitimidad y urgencia. Sin embargo, los estudios muestran que la percepción del directivo será la que finalmente determine la importancia de un “stakeholder” para la empresa. La literatura ha investigado en profundidad cómo reaccionan las empresas ante las presiones medioambientales por parte de los distintos “stakeholders”. Sin embargo, no se pocos investigadores se han centradoen las distintas estrategias que los “stakeholders” emplean para presionar a las empresas con prácticas que tengan en cuenta al medioambiente. Los “stakeholders” que tienen una menor capacidad para modificar el comportamiento de las empresas emplean tanto estrategias de presión directas (por ejemplo: boicots y manifestaciones ante las fábricas) como estrategias indirectas de presión (por ejemplo, a través del empleo de alianzas y el aumento de información para la sociedad sobre las prácticas medioambientales de las empresas). Este trabajo explora la presión social como estrategia indirecta de presión empleada por los “stakeholder” para modificar las decisiones medioambientales de las empresas y, a su vez mide la efectividad de dos mecanismos no coercitivos para modificar las decisiones respecto al medioambiente de los directivos con menor preocupación por el mismo. Para ello, un experimento, juego del dictador, se llevo a cabo para probar que los individuos que toman decisiones responden de forma distinta en términos de comportamiento si le afecta económicamente pero con consecuencias medioambientales. Los resultados muestran que la presión social puede ser utilizada como herramienta para modificar las decisiones sobre el medioambiente. Además, los resultados sugieren que la influencia de los “stakeholder” será mayor si el directivo/a es consciente que sus decisiones van a ser conocidas por cualquier “stakeholder” en cualquier de los mecanismo llevados a cabo en el experimento.Environmental issues are becoming increasingly important in organization theory and practice. Stakeholders – employees, suppliers, shareholders, regulators, non-governmental organizations – have played a crucial role in modifying firms’ environmental approach. Researchers suggest that a stakeholder’s saliency is the sum of its power, legitimacy and urgency. Yet, studies show that managers’ perception finally determines a stakeholder saliency. Stakeholder literature has investigated how firms react to pressures from stakeholders. However, few studies have focused on the diverse range of strategies a stakeholder can use to pressure firms to modify their environmental record. Stakeholders, which have less capacity to modify firms’ environmental behavior, use as direct pressure strategies (for example, boycotts and demonstrations) as indirect pressure strategies (network, alliances and spreading environmental information about a focal firm. This paper explores social pressure as a tool for modifying decisions regarding environment and checking the effectiveness of two non-coercive mechanisms to modify environmental decisions of those individuals that have no commitment to environment. For that purpose, a dictator game experiment was carried out aiming to prove that decision makers submitted to several social stimuli respond differently in terms of behaviors affecting them economically, but with environmental consequences. Results show that social pressure can be used as a tool for modifying decisions regarding environment. And, results also suggest that stakeholder influence is higher if a manager is aware that their decisions will be known by stakeholders in any of the mechanisms undertaken in this experiment

A use-side trade margins matrix for the Andalusian economy

According to the National Accounting Systems proposed by United Nations (1993) and Eurostat (1996), use and make (or supply) matrices should be measured before goods and services are conveyed to the markets (basic values). Actually, the make table is defined in basic values (excluding trade and transport margins and net commodity taxes) whereas the use table is in purchasers' values (including them). This paper shows how these margins and taxes can be removed from the use table with the purpose of entering both of them in the so-called material balance equation. With respect to trade margins, our approach is based on the use-side procedure from the ESA-95 Input-Output Manual (Eurostat, 2002) and is also being applied to the forthcoming 2000 Andalusian Input-Output Framework.Input-output analysis, use and make matrices, trade margins, National Accounts

Background Digital Calibration of Comparator Offsets in Pipeline ADCs

This brief presents a low-cost digital technique for background calibration of comparator offsets in pipeline analog-to-digital converters (ADCs). Thanks to calibration, comparator offset errors above half the stage least-significant bit margin in a unitary redundancy scheme are admissible, thus relaxing comparator design requirements and allowing their optimization for low-power high-speed applications and low input capacitance. The technique also makes it possible to relax design requirements of stage amplifiers within the pipeline queue, since output swing and driving capability are significantly lower. In this brief, the proposal is validated using realistic hardware-behavioral models.Junta de Andalucía P09-TIC-5386Gobierno Español TEC2011-2830

Achieving Replicability: Is There Life for Our Experiments After Publication?

Metaheuristics are algorithmic schemes that ease the derivation of novel algorithms to solve optimization problems. These algorithms are typically approximated and stochastic, leading to the preeminence of experimentation as the mean of supporting claims in research and applications. However, the huge number of variants and parameters of most metaheuristics, the ambiguity of natural language used in papers, and the lack of widely accepted reporting standards threatens the replicability of those experiments. This problem, that has been identified in the literature by several authors, significantly hinders the construction of a complete and cohesive body of knowledge on the behavior of metaheuristics. This paper proposes a set of minimum information guidelines for reporting metaheuristic experiments, and an experiment description language that supports the meeting of those guidelines. By using this language, metaheuristic optimization experiments are described in a toolindependent and unambiguous way, while maintaining readability and succinctness. Those contributions pave the way for replication using different problem instances and parameters, bringing a new life to metaheuristic experiments after publication.Ministerio de Ciencia e Innovación TIN2009-07366Ministerio de Economía y Competitividad TIN2012-32273Junta de Andalucía P07-TIC-2533Junta de Andalucía TIC-590

Random chopping in ΣΔ modulators

Organizado por la Universidad de Zaragoza (Unizar) del 18 al 20 de Noviembre del 2009Σ∆ modulators make a clever use of oversampling and exhibit inherent monotonicity, high linearity and large dynamic range but a restricted frequency range. As a result Σ∆ modulators are often the preferred option for sensor and instrumentation. Offset and Flicker noise are usual concerns for this type of applications and one way to minimize their effects is to use a chopper in the front-end integrator of the modulator. Frequency-shaped random chopping has been pro- posed to minimize the impact of reference voltage interference. It is shown in this paper that the chopper signal is not the only term that modulates the offset and Flicker noise and that unwanted crosstalk can significantly degrade the performance of the modulator.Junta de Andalucía EXC/2005/TIC-927Gobierno de España TEC-2007-6807

On chopper effects in discrete-time ΣΔ modulators

Analog-to-digital converters based on ΣΔ modulators are used in a wide variety of applications. Due to their inherent monotonous behavior, high linearity, and large dynamic range, they are often the preferred option for sensor and instrumentation. Offset and flicker noise are usual concerns for this type of applications, and one way to minimize their effects is to use a chopper in the front-end integrator of the modulator. Due to its simple operation principle, the action of the chopper in the integrator is often overlooked. In this paper, we provide an analytical study of the static effects in ΣΔ modulators, which shows that the introduction of chopper is not transparent to the modulator operation and should thus be designed with care.Gobierno de España TEC-2007-68072Consejo Superior de Investigaciones Científicas 200850I21

Closed-loop Simulation Method for Evaluation of Static Offset in Discrete-Time Comparators

This paper presents a simulation-based method for evaluating the static offset in discrete-time comparators. The proposed procedure is based on a closed-loop algorithm which forces the input signal of the comparator to quickly converge to its effective threshold. From this value, the final offset is computed by subtracting the ideal reference. The proposal was validated using realistic behavioral models and transistor-level simulations in a 0.18μm CMOS technology. The application of the method reduces by several orders of magnitude the number of cycles needed to characterize the offset during design, drastically improving productivity.Junta de Andalucía P09-TIC-5386Ministerio de Economía y Competitividad TEC2011-2830

Experiencing nature and children’s conceptualizations of the natural world

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Children's Geographies on 27/05/2016, available online: http://www.tandfonline.com/10.1080/14733285.2016.1190812This paper examines young children’s concepts of nature, paying attention to the role played by types of daily experiences with nature on 832 children’s constructions of the natural world. We observed the roles of three types of experiences, as determined by the children’s place of residence (urban, rural mountain range, and rural agricultural) in Spain. Participants wrote what they thought about when hearing the word ‘nature’. Content analysis revealed a conceptual structure formed with four underlying and interconnected themes: (1) natural and non-natural elements, (2) the human–nature relationship, (3) emotional experience of nature, and (4) actions in natural settings. The type of daily experiences with nature (i.e. urban, rural mountain range, and rural agricultural) accounted for variability in children’s concept of nature. These results reinforce the importance of considering the role played by personal and situational characteristics in shaping children’s constructions of the natural worldThis work was supported by the Spanish Ministry of Economy and Competitiveness [grant number PSI-2013-44939