Models teòrics explicatius de l'aprenentatge motor

En este artículo se repasan los principales modelos teóricos explicativos del aprendizaje motor. En un primer apartado se comentan las aportaciones propias de la psicología cognitiva y más concretamente del corriente del procesamiento de la información: la Teoría del bucle cerrado de Jack Adams y la Teoría del esquema de Richard Schmidt. Posteriormente, se exponen las críticas que han recibido estos modelos y, para hacerlo, se introducen las principales aportaciones que el científico ruso Nikolai Bernstein hizo al estudio del aprendizaje y el control motor. A partir de estas aportaciones, se introducen las formulaciones teóricas que, surgidas desde la perspectiva dinámica-ecológica, pretenden superar las limitaciones de los modelos cognitivos. Finalmente, se comparan las dos perspectivas y se sugieren algunas posibles vías de desarrollo futuro del campo que nos ocupa. _____________________________________________________________________________________________________________________________________________________________ Cet article permet à l’auteur de réviser les principaux modèles théoriques explicatifs de l’apprentissage moteur. Dans un premier chapitre, il commente les contributions propres de la psychologie cognitive et plus concrètement du courant du traitement de l’information: la théorie en boucle fermée de Jack Adams et la théorie du schéma de Richard Schmidt. Ensuite, il expose les critiques qu’ont reçues ces modèles et, pour ce faire, il introduit les principales contributions que le scientifique russe Nikolaï Bernstein a faites à l’étude de l’apprentissage et du contrôle moteur. À partir de ces contributions, il introduit les formulations théoriques, issues de la perspective dynamico-écologique, qui prétendent aller au-delà des limites des modèles cognitifs. Enfin, il compare les deux perspectives et suggèrent certaines voies possibles pour le développement à venir du domaine qui nous intéresse.En este artículo se repasan los principales modelos teóricos explicativos del aprendizaje motor. En un primer apartado se comentan las aportaciones propias de la psicología cognitiva y más concretamente del corriente del procesamiento de la información: la Teoría del bucle cerrado de Jack Adams y la Teoría del esquema de Richard Schmidt. Posteriormente, se exponen las críticas que han recibido estos modelos y, para hacerlo, se introducen las principales aportaciones que el científico ruso Nikolai Bernstein hizo al estudio del aprendizaje y el control motor. A partir de estas aportaciones, se introducen las formulaciones teóricas que, surgidas desde la perspectiva dinámica-ecológica, pretenden superar las limitaciones de los modelos cognitivos. Finalmente, se comparan las dos perspectivas y se sugieren algunas posibles vías de desarrollo futuro del campo que nos ocupa.In this article they go over the principle explanatory theoretical models of the learning motor. First of all they comment on the contributions made by cognitive psychology and more specifically of the ordinary processing of information: A Closed Loop Theory of Motor Control by Jack Adams and the Theory of the Plan by Richard Schmidt. Later, there is an explanation of the criticism that these models have received and, to do so, they introduce the principal contributions that the Russian scientist Nikolai Bernstein made with his study on learning and the control motor. From these contributions, they introduced the theoretical formulations with which, arisen from the dynamicecological perspective, they try to overcome the limitations of the cognitive models. Finally, they compare the two perspectives and suggest some possible channels of future development in the field of education

The added value of implementing the Planet Game scenario with Collage and Gridcole

This paper discusses the suitability and the added value of Collage and Gridcole when contrasted with other solutions participating in the ICALT 2006 workshop titled “Comparing educational modelling languages on a case study.” In this workshop each proposed solution was challenged to implement a Computer-Supported Collaborative Learning situation (CSCL) posed by the workshop’s organizers. Collage is a pattern-based authoring tool for the creation of CSCL scripts compliant with IMS Learning Design (IMS LD). These IMS LD scripts can be enacted by the Gridcole tailorable CSCL system. The analysis presented in the paper is organized as a case study which considers the data recorded in the workshop discussion as well the information reported in the workshop contributions. The results of this analysis show how Collage and Gridcole succeed in implementing the scenario and also point out some significant advantages in terms of design reusability and generality, user-friendliness, and enactment flexibility

Efficiency and endogenous fertility

This paper explores the properties of the notions of A-efficiency and P-efficiency, proposed by Golosov, Jones and Tertilt (Econometrica, 2007), to evaluate allocations in a general overlapping generations setting in which fertility choices are endogenously selected from a continuum and any two agents of the same generation are identical. First, we show that the properties of A-efficient allocations vary depending on the criterion used to identify potential agents. If one identifies potential agents by their position in their siblings' birth order --as Golosov, Jones and Tertilt do--, then A-efficiency requires that a positive measure of agents use most of their endowment to maximize the utility of the dynasty head, which, in environments with finite horizon altruism, implies that some agents --the youngest in every family-- obtain an arbitrary low income to finance their own consumption and fertility plans. If potential agents are identified by the dates in which they may be born, then A-efficiency reduces to dynastic maximization, which, in environments with finite horizon altruism, drives the economy to a collapse in finite time. To deal with situations, like those arising in economies with finite horizon altruism, in which A-efficiency may be in conflict with individual rights, we propose to evaluate the efficiency of a given allocation with a particular class of specifications of P-efficiency, for which the utility attributed to the unborn depends on the utility obtained by their living siblings. Under certain concavity assumptions on value functions, we also characterize every symmetric, P-efficient allocation as a Millian efficient allocation, that is, as a symmetric allocation that is not A-dominated --with the Birth-Order criterion-- by any other symmetric allocationFinancial support from the Spanish Minister of Economics and Competitivity project ECO2013-48884-C3-1-P is acknowledged by the first and the third authors, and from the Spanish Ministry of Science and Technology projects ECO2011-30323-C03-01 and ECO2014-59491-P by the second authorS

Low-Cost Hybrid Analog-Digital Beamformer Evaluation in Spectrum Sharing Systems

This paper evaluates different analog-digital beamforming solutions for future spectrum sharing mm-wave scenarios. In contrast to sub-6 GHz multiantenna schemes where all-digital solutions provide an excellent performance-cost tradeoff, in the mm-wave bands where a very large number of antennas is required, all-digital designs cannot be deployed due to their cost and complexity. In order to solve this problem, subarray solutions are conceived such that a reduced number of radiofrequency chains are simultaneously connected to different antennas through an analog beamforming network formed by phase shifters (i.e. with no amplitude control). Different connectivity solutions are evaluated; namely, full-connected, localized and interleaved considering that either the phase shifters have full resolution or only one control bit. As reported in the paper, while for the full resolution case the same performance is obtained for all connectivity schemes, in case the phase shifters have one control bit, differences show up. The numerical evaluation is done with an alternating feasible point pursuit successive convex approximation (FPP-SCA) optimization which yields to efficient solutions even for this non-convex optimization problem

Performance Analysis of Joint Precoding and MUD Techniques in Multibeam Satellite Systems

This paper considers interference mitigation techniques in the forward link of multibeam satellite systems. In contrast to previous works, either devoted to receiver interference mitigation (e.g. multiuser detection) or transmitter interference mitigation (precoding), this work evaluates the achievable rates of the joint combination of both techniques. On the one hand, precoding cannot properly mitigate all the inter- beam interference while maintaining a sufficiently high signal-to-noise ratio. On the other hand, the receiver cost and complexity exponentially increases with the number of signals to be simultaneously detected. This highlights that the receiver cannot deal with all the interferences so that in general only 2 signals are jointly detected. As a result, the use of precoding within a coverage area jointly with multiuser detection can both benefit from each other and extremely increase the achievable rates of the system. This is numerically evaluated in a close-to-real coverage area considering simultaneous non-unique decoding strategies. The results show the benefits of this joint scheme that eventually can increase the current precoding performance a 23%

MIMO channel metrics

Space diversity processing when suitable either at the transmitter side or at the receiver side provides a reduction on the transmitted power for the same received signal quality. The paper discusses the importance of the channel entropy in order to design, derived directly from the channel sounder, first, a system able to decide whether it is worth that the transmitter knows the channel or not (CSIT or Channel State Information at the Transmitter). Second, a channel metric is proposed in order to classify the channel regardless of the Tx-Rx space processing to be used. Among other aspects, this channel classifier would help in designing a vector quantifier to feedback the channel state information to the transmitter when CSIT is required.Postprint (published version