Optimized battery sizing for merchant solar PV capacity firming in different electricity markets

Comunicació presentada a IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society (Lisbon, Portugal 14-17 Oct. 2019)This work analyses the minimum energy capacity requirements to be demanded to battery energy storage systems used in megawatt-range merchant solar PV plants to grant capacity firming. The operation of such a plant is simulated (with a 2-minute time step, at three different locations of the Iberian Peninsula, and for different battery sizes) after solving a quadratic programming optimization problem. The control algorithm takes into account the irradiance forecast and the intraday electricity market configuration, which presents certain peculiarities in the Iberian region with regard to other European markets. The analysis has been performed in an annual basis and current irradiance measured values have been used

Renovación intelectual y prestigio social: "Novatores", academias e instituciones públicas en la Valencia de finales del siglo XVII y principios del XVIII

Los partidarios de la renovación literaria, científica y filosófica alcanzaron gran prestigio e influencia en la Valencia de finales del siglo XVII. La fundación de academias de diferentes tipos y orientaciones constituye la más acabada expresión de esta realidad. El nacimiento de la Academia del Alcázar, las actividades desarrolladas por sus miembros como manifestación de una incipiente cultura cortesana durante la penúltima década de la centuria y la dimensión política que cabe atribuir a todas ellas son analizadas en la segunda parte de este artículo. (A

Ultra-Broadband Directional Couplers Using Microstrip with Dielectric Overlay in Millimeter-Wave Band

Nowadays, millimeter-wave systems are being a key factor to develop wide band applications. In this paper, a directional coupler in millimeter-wave band using dielectric overlay is presented. This leads us to technology aspects, in directional coupler design, are key points to achieve the proper response of the circuit. The coupler proposed in this paper covers the 15-45 GHz band and its response has 15-dB coupling-level, 1-dB coupling-ripple and a reflection coefficient better than 10 dB

Model Interpretability through the Lens of Computational Complexity

In spite of several claims stating that some models are more interpretable than others -- e.g., "linear models are more interpretable than deep neural networks" -- we still lack a principled notion of interpretability to formally compare among different classes of models. We make a step towards such a notion by studying whether folklore interpretability claims have a correlate in terms of computational complexity theory. We focus on local post-hoc explainability queries that, intuitively, attempt to answer why individual inputs are classified in a certain way by a given model. In a nutshell, we say that a class $\mathcal{C}_1$ of models is more interpretable than another class $\mathcal{C}_2$, if the computational complexity of answering post-hoc queries for models in $\mathcal{C}_2$ is higher than for those in $\mathcal{C}_1$. We prove that this notion provides a good theoretical counterpart to current beliefs on the interpretability of models; in particular, we show that under our definition and assuming standard complexity-theoretical assumptions (such as P$\neq$NP), both linear and tree-based models are strictly more interpretable than neural networks. Our complexity analysis, however, does not provide a clear-cut difference between linear and tree-based models, as we obtain different results depending on the particular post-hoc explanations considered. Finally, by applying a finer complexity analysis based on parameterized complexity, we are able to prove a theoretical result suggesting that shallow neural networks are more interpretable than deeper ones.Comment: 36 pages, including 9 pages of main text. This is the arXiv version of the NeurIPS'2020 paper. Except from minor differences that could be introduced by the publisher, the only difference should be the addition of the appendix, which contains all the proofs that do not appear in the main tex

Competencias éticas en la práctica profesional de las/los trabajadoras/es sociales con personas mayores

El present article té com objectiu presentar els resultats sobre una subescala suministrada a treballadors socials, a Portugal, que intervenen amb personas grans i que avalua les seves competències el que fa a «Valors, ètiques i perspectives teòriques». L'estudi, a més d'analitzar l'estructura factorial i les propietats psicomètriques de la subescala, compara les puntuacions mitjanes amb les d'altres països. La investigació es va fer amb les/els traballadores/ors socials que assumeixen funcions de lideratge en les respostes socials dirigides a personas grans (n = 387). Els resultats indiquen una estructura bifactorial (competències transversals versus competències especialitzades sobre la pràctica professional), i que explica aproximadament el 64,72% de la variança. La consistència interna va ser de 0,90 (α de Cronbach). Les diferències de les medies trobades, que són superiors a Portugal, especialment en les competències transversals que porten a la integració dels valors i les ètiques a la pràctica professional, ens porten a considerar que, malgrat l'absència d'un codi d'ètica portuguès, el projecte educatiu i professional està basat en la centralitat dels valors i de l'ètica.This article presents the results of the administration, in Portugal, of a subscale that evaluates the competencies of social workers working with elderly users regarding “Values, Ethics and Theoretical Perspectives.” In addition to examining the factor structure and the psychometric properties of the subscale, the study compares the mean scores with those of samples collected in other countries. The research was carried out with social workers who assume leadership roles in social institutions targeted at the elderly population (n = 387). The results indicate a two-factor structure (transversal competences vs. specialized skills related to professional practice), which explains about 64.72% of the variance. The internal consistency was 0.90 (Cronbach’s α). The average differences found in Portugal, especially in transversal competencies that refer to the integration of values and ethics in professional practice, reveal that despite the absence of a Portuguese code of ethics, the educational and professional project of social workers is based on the centrality of values and ethics.El presente artículo tiene como objetivo presentar los resultados sobre una subescala suministrada a trabajadores sociales, en Portugal, que intervienen con personas mayores y que evalúa las competencias de estos acerca de los «Valores, éticas y perspectivas teóricas». El estudio, además de analizar la estructura factorial y las propiedades psicométricas de la subescala, compara las puntuaciones medias con las de otros países. La investigación se hizo con las/los trabajadoras/es sociales que asumen funciones de liderazgo en las respuestas sociales dirigidas a personas mayores (n = 387). Los resultados indican una estructura bifactorial (competencias transversales versus competencias especializadas sobre la práctica profesional), y que explica aproximadamente el 64,72% de la varianza. La consistencia interna fue de 0,90 (α de Cronbach). Las diferencias de las medias encontradas, que son superiores en Portugal, especialmente en las competencias transversales que conducen a la integración de los valores y las éticas en la práctica profesional, nos llevan a considerar que, a pesar de la ausencia de un código de ética portugués, el proyecto educativo y profesional está basado en la centralidad de los valores y de la ética

Analysis of the initial thermal stabilization and air turbulences effects on Laser Tracker measurements

During the several last years, Laser Trackers have become more common as a measurement tool in the manufacture and assembly of large components such as aircraft wings and ship hulls, as well as for error mapping in coordinate measuring machines and machine tools. Most of these processes cannot be developed in a controlled metrological laboratory but must be implemented directly on a shop floor. Therefore, the process of stabilization of the Laser Tracker has been studied in several experimental tests, and it has been observed that the warm-up time suggested by the manufacturer is not enough. During the first hours of the measurement process two types of thermal errors significantly affect the measurements, causing inaccuracies of between 20 and 80 µm, depending on the equipment used and the positions of the measured points. These thermal errors are systematic and repeatable; therefore they can be estimated and compensated for each measurement system. Because environmental conditions on a shop floor cannot be controlled, once the Laser Tracker is stabilized, the effects of ambient air in measurements have also been studied, focusing on the effect of turbulent flows on the beam path. It has been observed that this turbulence may cause radial distance drifts on the order of micrometers, deflection of the beam trajectory and signal loss

Study on Machine Tool Positioning Uncertainty Due to Volumetric Verification

Volumetric verification is based on the machine tool (MT) kinematic model, along with its geometric errors. Although users often ignore the uncertainty of verification, the use of the MT as a traceable measurement system in the manufacturing process has increased the need for professionals to be aware of it. This paper presents an improvement in the MT kinematic model, introducing in it the influence of verification uncertainty sources. These sources have been classified into four groups: the MT, the measurement system itself, the measurement strategy, and the optimization strategy. As the developed model exhibits non-linear behavior, the Monte Carlo method was used to determine the influence of the measurement system on verification uncertainty using synthetic tests. In this manner, an improved estimation of the MT uncertainty can be obtained. Therefore, if the MT is used as a traceable measurement system, its accuracy should not be higher than the laser tracker (LT) verification influence. It hence shows the importance of LT influence

Algorithm to optimize measurement system location in a machine tool verification

Nowadays, machine tool accuracy is a competitive element. To improve it, machine tools are verified and compensate periodically reducing the influence of their geometric errors. As geometric errors have systematic behavior, their influence can be compensated after verification. However, verification itself is influenced by random uncertainty sources that affect verification results. Within all influences on machine tool volumetric verification, laser tracker measurement noise is a random uncertainty source that is not usually considered. However, it should not be ignored and can be reduced through an adequate location. This paper presents an algorithm able to analyze the influence of laser tracker location, taking into consideration its specifications and machine tool characteristics. To do that, the developed algorithm provides a zone around MT to locate the measurement system using the Monte Carlo Method. Moreover, it provides the probability distribution function of laser tracker influence related to LT location zone. Therefore, if MT is used as a traceable measurement system, its uncertainty cannot be smaller than LT location uncertainty

Configuration optimisation of laser tracker location on verification process

Machine tools are verified and compensated periodically to improve accuracy. The main aim of machine tool verification is to reduce the influence of quasi-static errors, especially geometric errors. As these errors show systematic behavior, their influence can be compensated. However, verification itself is influenced by random uncertainty sources that are usually not considered but affect the results. Within these uncertainty sources, laser tracker measurement noise is a random error that should not be ignored and can be reduced through adequate location of the equipment. This paper presents an algorithm able to analyse the influence of laser tracker location based on nonlinear optimisation, taking into consideration its specifications and machine tool characteristics. The developed algorithm uses the Monte Carlo method to provide a zone around the machine tool where the measurement system should be located in order to improve verification results. To achieve this aim, different parameters were defined, such as the number of tests carried out, and the number and distribution of points, and their influence on the error due to the laser tracker location analysed