Operator product expansion and quark condensate from Lattice QCD in coordinate space

We present a Lattice QCD determination of the chiral quark condensate based on a new method. We extract the quark condensate from the operator product expansion of the quark propagator at short euclidean distances, where it represents the leading contribution in the chiral limit. From this study we obtain ^ms(2 GeV)=-(265+-5+-22 MeV)^3$, in good agreement with determinations of this quantity based on different approaches. The simulation is performed by using the O(a)-improved Wilson action at beta=6.45 on a volume 32^3\times70 in the quenched approximation

Monitorización de las cargas de entrenamiento en corredores de fondo y medio fondo de alto nivel

El principal objetivo del entrenamiento consiste en mejorar el rendimiento y, por ende, reducir lesiones. Para ello, la monitorización de dicha carga (interna, externa y su relación) se ha constatado como vital. Sin embargo, muchos entrenadores siguen sin controlar (o etéreamente) las cargas en sus deportistas, pues, además, no existe un sistema etiquetado como el ideal. Consecuentemente, teniendo en cuenta el contexto y lo que la literatura dice al respecto, se realizó una propuesta personal con corredores de resistencia de alto nivel, contabilizando, en cuanto a carga externa, volumen mediante los kilómetros recorridos semanalmente, intensidad mediante la velocidad de carrera con zonas de entrenamiento en función del perfil individual de lactato, y frecuencia registrando el número de entrenamientos y de los contenidos trabajados. Respecto al estrés interno, la Escala de Esfuerzo Percibido y la medición de la altura del salto vertical con contramovimiento, en pos de determinar la fatiga neuromuscular subaguda. Los resultados mostraron relación significativa en la mayoría de variables, haciendo que el objetivo e hipótesis que perseguía la intervención se cumplan en mayor o menor medida, por lo que el sistema de monitorización escogido y/o los diferentes ítems que lo componen podrían ser válidos para su utilización en otros contextos.The main objective of training is to improve performance and, therefore, reduce injuries. For that reason, the monitoring of this load (internal, external and their relationship) has been verified as vital. However, many trainers still do not control (or ethereally) the loads on their athletes. In addition, there is not system labeled as the ideal. Consequently, taking into account the context and what the literature says about it, a personal research was made with high-level resistance runners, accounting, in terms of external load, volume through the kilometers traveled weekly, intensity through the running speed with training zones depending on the individual lactate profile, and frequency recording the number of training sessions and the contents worked. Regarding internal stress, the Rating of Perceived Exertion and a measurement of countermovement jump height, in order to determine subacute neuromuscular fatigue. The results showed a significant relationship in most variables, making the objective and hypothesis of the intervention have been met to a greater or lesser extent, so that the chosen monitoring system and / or the different items that comprise it could be valid for its use in other contexts.info:eu-repo/semantics/publishedVersio

Simulated annealing techniques for joint transmitter-receiver design in a multiple user access MIMO-OFDM channel

In this paper we consider the problem of the joint design of multiple transmitters and receivers in a MIMe- eFDM scenario. We consider that both the transmitters and receivers have multiple antennas, configuring a Multi-Input-Multi-Output (MIMe) channel. Based on this structure, space diversity techniques can be used to separate the signals transmitted by different users. Concretely, the proposed approach consists in beamforming at both sides of the system, combined with the Orthogonal-Frequency-Division-Multiplexing (eFDM) modulation. The goal is the minimization of the total transmitted power subject to constraints related to the Quality of Service (QoS) for each user in terms of the Bit Error Rate (BER) and the maximum transmitted power for some terminals. By making use of this approach, the Multiple Access Interference (MAI) is minimized and the physical resources are exploited in an optimum way. The design is based on Simulated Annealing (SA), an heuristic technique able to find the optimum design in this non-convex problem and that can take into account all kind of constraints.Postprint (published version

Exploiting transmission spatial diversity in frequency selective systems with feedback channel

In this paper we address the design of a multiple transmit antenna system in which the Channel State Information (CSI) at the transmitter is not perfect. Two different approaches are analyzed one based on the Minimization of the Mean Square Error (MMSEj and the other based on the application of the Maximum Likelihood Sequence Estimation (MLSE). In both cases a Bayesian criterion is used in order to take into account the error between the CSI and the real channel. Finally, some simulation results and conclusions are provided, showing which is the gain of these approaches when the error between the CSI and the real channel is either Gaussian or uniform, where this last case corresponds to a quantization of the channel time response in order to transmit the CSI through a feedback channel from the receiver to the transmitter.Postprint (published version

Análisis del golpeo y la preparación psicológica para retornar a la práctica en futbolistas tras una lesión isquiosural

Las lesiones de la musculatura isquiosural son las más comunes en fútbol, y pueden presentar efectos residuales que cambien el patrón de un gesto técnico. El presente estudio analizó las diferencias en la técnica de golpeo entre jugadores anteriormente lesionados y jugadores no lesionados, así como las correlaciones entre la capacidad psicológica para retornar a la práctica y las características del gesto. Tres futbolistas que habían padecido una lesión de isquiosurales conformaron el grupo de jugadores anteriormente lesionados, y tres futbolistas que no habían padecido ninguna lesión en el miembro inferior en los últimos dos años, formaron el grupo de jugadores no lesionados. Se analizaron los gestos de golpeo a balón parado y de golpeo en carrera a través del programa Kinovea. Asimismo, se evaluó la capacidad psicológica para retornar a la práctica mediante el Injury Psychological Readiness to Return to Sport (I-PRRS). Únicamente la velocidad del balón en el golpeo en carrera presentó diferencias significativas entre grupos (p<0,05). Además, se obtuvieron correlaciones positivas entre la preparación psicológica para retornar y la flexión de rodilla en el golpeo en carrera, y entre la flexión de rodilla en el golpeo a balón parado y los ítems 3 y 4 del I-PRRS. Asimismo, se hallaron correlaciones negativas entre la extensión de cadera en el golpeo a balón parado y el ítem 6 del I-PRRS. Los resultados permiten concluir que variables cinemáticas y variables psicológicas se encuentran interrelacionadas tras una lesión en la musculatura isquiosural.info:eu-repo/semantics/publishedVersio

UMat: Uncertainty-Aware Single Image High Resolution Material Capture

We propose a learning-based method to recover normals, specularity, and roughness from a single diffuse image of a material, using microgeometry appearance as our primary cue. Previous methods that work on single images tend to produce over-smooth outputs with artifacts, operate at limited resolution, or train one model per class with little room for generalization. Previous methods that work on single images tend to produce over-smooth outputs with artifacts, operate at limited resolution, or train one model per class with little room for generalization. In contrast, in this work, we propose a novel capture approach that leverages a generative network with attention and a U-Net discriminator, which shows outstanding performance integrating global information at reduced computational complexity. We showcase the performance of our method with a real dataset of digitized textile materials and show that a commodity flatbed scanner can produce the type of diffuse illumination required as input to our method. Additionally, because the problem might be illposed -- more than a single diffuse image might be needed to disambiguate the specular reflection -- or because the training dataset is not representative enough of the real distribution, we propose a novel framework to quantify the model's confidence about its prediction at test time. Our method is the first one to deal with the problem of modeling uncertainty in material digitization, increasing the trustworthiness of the process and enabling more intelligent strategies for dataset creation, as we demonstrate with an active learning experiment.Comment: CVPR 2023. Project website: https://carlosrodriguezpardo.es/projects/UMat

A robust maximin approach for MIMO communications with imperfect channel state information based on convex optimization

This paper considers a wireless communication system with multiple transmit and receive antennas, i.e., a multiple-input-multiple-output (MIMO) channel. The objective is to design the transmitter according to an imperfect channel estimate, where the errors are explicitly taken into account to obtain a robust design under the maximin or worst case philosophy. The robust transmission scheme is composed of an orthogonal space–time block code (OSTBC), whose outputs are transmitted through the eigenmodes of the channel estimate with an appropriate power allocation among them. At the receiver, the signal is detected assuming a perfect channel knowledge. The optimization problem corresponding to the design of the power allocation among the estimated eigenmodes, whose goal is the maximization of the signal-to-noise ratio (SNR), is transformed to a simple convex problem that can be easily solved. Different sources of errors are considered in the channel estimate, such as the Gaussian noise from the estimation process and the errors from the quantization of the channel estimate, among others. For the case of Gaussian noise, the robust power allocation admits a closed-form expression. Finally, the benefits of the proposed design are evaluated and compared with the pure OSTBC and nonrobust approaches.Postprint (published version

Flexible MIMO architectures: guidelines in the design of MIMO parameters

One of the multiple advantages of communicating through MIMO systems is their inherent ability to provide flexible configurations. Following this line of thought, in this paper we present a generic framework to study the degrees of freedom in the design of MIMQ communication systems (e.g.: code length, number of multiplexed streams, or receiver structure). Precisely, we focus our efforts to bridge the gap between the design of MIMO systems with full and no channel state information at the transmitter side and also with different complexiry degrees at ihe receiver side. For instance, we can establish a trade-off, not only between the achievable rates and the diversity or beamforming gains, but also between the rate and the robustness to uncertainties in the channel state information.Postprint (published version

TracEDaaS: Captura y Trazabilidad de Artefactos del Proceso de Diseño

Se presenta una herramienta, TracEDaaS, que permite la captura y la trazabilidad de la evolución de los productos del proceso de diseño de software, soportando el refinamiento y la elaboración iterativa del mismo. TracEDaaS ha sido implementada como un servicio en la nube bajo el modelo “Software as a Service” (SaaS) y permite representar junto a las versiones de los objetos del diseño, información que permite la trazabilidad de los artefactos del proceso de desarrollo, manteniendo la navegabilidad entre los distintos modelos y las diferentes versiones de los mismos. Esta información está estructurada en término de las operaciones aplicadas a los objetos de diseño. La herramienta es lo suficientemente flexible para soportar nuevos problemas de diseño en término de los conceptos particulares del dominio y las posibles operaciones que pueden ser aplicadas a las instancias de tales conceptos.Fil: Hernandez, Federico. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roldán, María Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Vegetti, Maria Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Gonnet, Silvio Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Leone, Horacio Pascual. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin