559 research outputs found

    Propuesta para abordar el modelo cuántico del átomo en el bachillerato

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    Objetivo: Dar las bases para abordar el modelo cuántico del átomo a nivel bachillerato. Marco teórico: Aprendizaje significativo y colaborativo. Metodología: Con la secuencia diseñada y probada en el aula se lleva a los estudiantes al proceso de construcción de los elementos que implican un modelo del átomo: existe, tiene estructura (electrones y núcleo), la estructura electrónica determina todas sus propiedades. La meta es que los alumnos entiendan que el modelo cuántico explica la física atómica, en particular la tabla periódica. Las estrategias utilizadas consisten en experimentos y simulaciones, trabajo colaborativo, discusión guiada y evaluación de aprendizajes. Conclusiones: Sin pretender emplear el formalismo de la física cuántica, con esta propuesta la dificultad conceptual para los estudiantes es similar a la de modelos provisionales como el de Bohr

    Automatic Safe Data Reuse Detection for the WCET Analysis of Systems With Data Caches

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    Worst-case execution time (WCET) analysis of systems with data caches is one of the key challenges in real-time systems. Caches exploit the inherent reuse properties of programs, temporarily storing certain memory contents near the processor, in order that further accesses to such contents do not require costly memory transfers. Current worst-case data cache analysis methods focus on specific cache organizations (LRU, locked, ACDC, etc.). In this article, we analyze data reuse (in the worst case) as a property of the program, and thus independent of the data cache. Our analysis method uses Abstract Interpretation on the compiled program to extract, for each static load/store instruction, a linear expression for the address pattern of its data accesses, according to the Loop Nest Data Reuse Theory. Each data access expression is compared to that of prior (dominant) memory instructions to verify whether it presents a guaranteed reuse. Our proposal manages references to scalars, arrays, and non-linear accesses, provides both temporal and spatial reuse information, and does not require the exploration of explicit data access sequences. As a proof of concept we analyze the TACLeBench benchmark suite, showing that most loads/stores present data reuse, and how compiler optimizations affect it. Using a simple hit/miss estimation on our reuse results, the time devoted to data accesses in the worst case is reduced to 27% compared to an always-miss system, equivalent to a data hit ratio of 81%. With compiler optimization, such time is reduced to 6.5%

    Los Servicios Públicos. Una Exigencia de Nuestro Tiempo

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    User involvement before the development of an indoor RPAS for the creative industries

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    [EN] This paper presents user needs and preferences gathered prior to the development of an indoor remotely piloted air system. A literature review was carried out to analyse previous studies about the involvement of users in the design of indoor unmanned aerial vehicles. Subsequently, the results of these user needs obtained from three focus groups held in European countries (Belgium, Spain and United Kingdom) are presented here. Through a content analysis of the information obtained in the focus groups, 40 codes and 4 variables were defined and used to examine the differences between types of users and their previous experience with drones. The literature review gave support to the results obtained through users¿ involvement in the features to be included in a new unmanned aerial vehicle. Non-parametric tests and qualitative comparative analysis were used to analyse the information gathered in the focus groups. The results revealed few differences between artists working in creative industries and drone operators working for the creative industries. These differences affected features such as detecting and avoiding obstacles, which requires the inclusion of sensors. In addition, previous experience with drones was found to be a sufficient condition to explain greater concerns over safety, ethical and security issues in indoor environments.The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: This work was supported by the European Commission (H2020, grant number 732433).De-Miguel-Molina, B.; De-Miguel-Molina, M.; Santamarina-Campos, V.; Segarra-Oña, M. (2021). User involvement before the development of an indoor RPAS for the creative industries. International Journal of Micro Air Vehicles. 13:1-14. https://doi.org/10.1177/17568293219921401141

    The Experiences of Students in the Modular and Online Learning: A Phenomenological Study

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    This study aimed to determine the specific experiences of university students in terms of cognitive, social, emotional, and adversity skills in an online or modular mode of learning. The study utilized a phenomenology research design, and a semi-structured interview was conducted. Participants in the study were composed of students enrolled in online and modular learning who were asked to share their experiences elaborately. The analysis revealed that despite the differences in the learning modalities, the students similarly experienced the same significant adjustments and academic challenges. These experiences include the lack or limited access to information, concerns about the accessibility of the learning opportunities, lack of economic resources, time management concerns, communication with professors and classmates, and self-motivation and coping mechanisms. As an intended outcome, a feasible distance learning blueprint composed of possible courses of action that can be taken to achieve a more effective and feasible distance learning setup is made

    Innovation as a driver of eco-innovation in the firm: an approach from the dynamic capabilities theory

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    The aim of this study is to investigate how innovative capabilities of the firm affect eco-innovation from a dynamic capability lens. We build on OECD’s (2005) research to conceptualise eco-innovation as the capacity with which firms modify, re-design, and create products, processes, procedures and organisations in order to reduce environmental impact. We propose and test the temporal and relational properties of eco-innovation as a capability. We demonstrate that eco-innovation possesses two properties of innovative capabilities, namely, persistence over time and interrelation with other innovations. We thus shed new light on the mechanism through which firms engage in eco-innovation. We also provide empirical evidence to the debate on the relationship between the ‘normal’ innovation (technological or non-technological) and eco-innovation. We show that eco-innovation and innovation are interrelated both simultaneously and sequentially. Moreover, we show that innovation capabilities and eco-innovation are not only related, but they also have a complementary nature, which facilitates the development of future eco-innovation

    A method for real-time identification and tracking of traveling ionospheric disturbances using ionosonde data: first results

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    Traveling Ionospheric Disturbances (TIDs) are wave-like propagating irregularities that alter the electron density environment and play an important role spreading radio signals propagating through the ionosphere. A method combining spectral analysis and cross-correlation is applied to time series of ionospheric characteristics (i.e., MUF(3000)F2 or foF2) using data of the networks of ionosondes in Europe and South Africa to estimate the period, amplitude, velocity and direction of propagation of TIDs. The method is verified using synthetic data and is validated through comparison of TID detection results made with independent observational techniques. The method provides near real time capability of detection and tracking of Large-Scale TIDs (LSTIDs), usually associated with auroral activity.Postprint (published version
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