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In the dynamic world of sports, hamstring injuries are a constant concern for athletes and health professionals. However, a ray of hope has emerged with the REHABTECH project, a revolutionary wearable device developed in the field of biomedical engineering. REHABTECH is presented as a comprehensive solution for post-rehabilitation of hamstring injuries, specially designed for athletes. This portable and easy-to-use device focuses on the precise execution of the deadlift, an essential exercise for strengthening this critical area. The highlight of REHABTECH is its ability to provide real-time information through LED and audible alerts. While performing the deadlift, the device provides visual cues indicating whether form is correct or whether adjustments are necessary. This not only helps prevent further injuries, but also ensures effective and personalized rehabilitation., En el dinámico mundo del deporte, las lesiones de los isquiotibiales son una preocupación constante para los deportistas y profesionales de la salud. Sin embargo, ha surgido un rayo de esperanza con el proyecto REHABTECH, un dispositivo portátil revolucionario desarrollado en el campo de la ingeniería biomédica. REHABTECH se presenta como una solución integral para la post-rehabilitación de lesiones de isquiotibiales, especialmente diseñada para deportistas. Este dispositivo portátil y fácil de usar se centra en la ejecución precisa del peso muerto, ejercicio fundamental para fortalecer esta zona crítica. Lo más destacado de REHABTECH es su capacidad de proporcionar información en tiempo real a través de alertas LED y auditivas. Durante la ejecución del peso muerto, el dispositivo emite señales visuales que indican si la forma es correcta o si es necesario realizar ajustes. Esto no sólo ayuda a prevenir lesiones adicionales, sino que también garantiza una rehabilitación eficaz y personalizada.

We introduce a novel writing method called Probing Chain-of-Thought (ProCoT), which potentially prevents students from cheating using a Large Language Model (LLM), such as ChatGPT, while enhancing their active learning. LLMs have disrupted education and many other fields. For fear of students cheating, many have resorted to banning their use. These LLMs are also known for hallucinations. We conduct studies with ProCoT in two different courses with 65 students. The students in each course were asked to prompt an LLM of their choice with one question from a set of four and required to affirm or refute statements in the LLM output by using peer-reviewed references. The results show two things: (1) ProCoT stimulates creative/critical thinking and writing of students through engagement with LLMs when we compare the LLM-only output to ProCoT output and (2) ProCoT can prevent cheating because of clear limitations in existing LLMs, particularly ChatGPT, when we compare students' ProCoT output to LLM ProCoT output. We also discover that most students prefer to give answers in fewer words than LLMs, which are typically verbose. The average word counts for students in the first course, ChatGPT (v3.5), and Phind (v8) are 208, 391 and 383, respectively., Comment: 8 pages, 4 figures

End-to-end learning has become a popular method for joint transmitter and receiver optimization in optical communication systems. Such approach may require a differentiable channel model, thus hindering the optimization of links based on directly modulated lasers (DMLs). This is due to the DML behavior in the large-signal regime, for which no analytical solution is available. In this paper, this problem is addressed by developing and comparing differentiable machine learning-based surrogate models. The models are quantitatively assessed in terms of root mean square error and training/testing time. Once the models are trained, the surrogates are then tested in a numerical equalization setup, resembling a practical end-to-end scenario. Based on the numerical investigation conducted, the convolutional attention transformer is shown to outperform the other models considered., Comment: final version to Photonics Technology Letters (02/01/2024)

Magnesium (Mg2+) is one of the most common impurities in calcite and is known to have a non‐linear impact on the solubility of magnesian calcites. Using molecular dynamics (MD), we observed that Mg2+ impacts overall surface energies, local free energy profiles, interfacial water density, structure and dynamics and, at higher concentrations, it also causes crystal surface deformation. Low Mg concentrations did not alter the overall crystal structure, but stabilised Ca2+ locally and tended to increase the etch pit nucleation energy. As a result, Ca‐extraction energies over a wide range of 39 kJ/mol were observed. Calcite surfaces with an island were less stable compared to flat surfaces, and the incorporation of Mg2+ destabilised the island surface further, increasing the surface energy and the calcium extraction energies. In general, Ca2+ is less stable in islands of high Mg2+ concentrations. The local variation in free energies depends on the amount and distance to nearest Mg in addition to local disruption of interfacial water and the flexibility of surface carbonate ions to rotate. The result is a complex interplay of these characteristics that cause variability in local dissolution energies. Taken together, these results illustrate molecular scale processes behind the non‐linear impact of Mg2+ concentration on the solubility of magnesium‐bearing calcites.

The effect of stoichiometry on the new formation and subsequent growth of CaCO3 was investigated over a large range of solution stoichiometries (10–4 < raq < 104, where raq = {Ca2+}:{CO32–}) at various, initially constant degrees of supersaturation (30 < Ωcal < 200, where Ωcal = {Ca2+}{CO32–}/Ksp), pH of 10.5 ± 0.27, and ambient temperature and pressure. At raq = 1 and Ωcal < 150, dynamic light scattering (DLS) showed that ion adsorption onto nuclei (1–10 nm) was the dominant mechanism. At higher supersaturation levels, no continuum of particle sizes is observed with time, suggesting aggregation of prenucleation clusters into larger particles as the dominant growth mechanism. At raq ≠ 1 (Ωcal = 100), prenucleation particles remained smaller than 10 nm for up to 15 h. Cross-polarized light in optical light microscopy was used to measure the time needed for new particle formation and growth to at least 20 μm. This precipitation time depends strongly and asymmetrically on raq. Complementary molecular dynamics (MD) simulations confirm that raq affects CaCO3 nanoparticle formation substantially. At raq = 1 and Ωcal ≫ 1000, the largest nanoparticle in the system had a 21–68% larger gyration radius after 20 ns of simulation time than in nonstoichiometric systems. Our results imply that, besides Ωcal, stoichiometry affects particle size, persistence, growth time, and ripening time toward micrometer-sized crystals. Our results may help us to improve the understanding, prediction, and formation of CaCO3 in geological, industrial, and geo-engineering settings.

This thesis studies the stochastic root-finding problem, which consists of estimating the point x∗ that solves the equation h(x∗) = 0, where the function h : (0,1) → R is learned via a stochastic simulator (oracle). Instead of focusing on modeling h(·), we develop statistical methodologies that directly infer x∗ following a fully Bayesian approach. To do so, we investigate procedures that generalize the Probabilistic Bisection Algorithm (PBA) first introduced in Horstein (1963). The PBA is a one-dimensional stochastic root-finding routine which builds an explicit Bayesian representation (i.e., a posterior density) for x∗ based on the history of noisy function evaluations and sampling locations. The PBA starts by assuming that x∗ is the realized value of an absolutely continuous random variable, X∗ ∼ g0, with prior density g0. Then, it recursively updates a posterior, gn, leveraging the information provided by the signs (positive/negative) of the noisy function evaluations — which inform the direction where x∗ is located with respect to a given location, x—. Due to observational noise, the oracle responses are correct only with probability p(x). Waeber et al. (2013) showed that sampling at the median of gn is an optimal sampling strategy and established exponential convergence of the posterior gn to a Dirac mass at the true x∗ under the very restrictive assumption that the probability of correct response p(x) is known and constant for all x; however, in the most general and practical settings the latter condition no longer holds and the only way to implement the PBA is to estimate p(·).In the first part of this thesis, we state the Generalized PBA (G-PBA), where the above assumption is relaxed to the case where the sampling distribution of the oracle is unknown and location-dependent. Namely, as in standard PBA, we rely on a knowledge state to approximate the posterior of the root location. To implement the corresponding Bayesian updating, we also carry out inference

Classical molecular dynamics (MD) simulations were used to study the effects of water on the structural relaxation of the surfaces of bio-active phosphate-based glasses with compositions (P2O5)0.45(CaO)x(Na2O)0.55-x (x = 0.30, 0.35 and 0.40). Direct comparison of the data for the three compositions showed that surfaces with x = 0.30 experienced the highest calcium diffusion, as well as highest sodium concentration at the glass/water interface, confirming these systems as the most soluble of the three compositions studied. Our results also show the importance of surface hydroxylation in the simulation of these types of bio-glasses, which causes differential relaxation of the surfaces, leading to changes in network polymerization that modulate the diffusion of water and modifiers into and out of the glasses, with direct impact on dissolution.

The dehydration of cations is generally accepted as the rate-limiting step in many processes. Molecular dynamics (MD) can be used to investigate the dynamics of water molecules around cations, and two different methods exist to obtain trajectory-based water dehydration frequencies. Here, these two different post-processing methods (direct method versus survival function) have been implemented to obtain calcium dehydration frequencies from a series of trajectories obtained using a range of accepted force fields. None of the method combinations reproduced the commonly accepted experimental water exchange frequency of 10-8.2 s-1. Instead, our results suggest much faster water dynamics, comparable with more accurate ab initio MD simulations and with experimental values obtained using neutron scattering techniques. We obtained the best agreement using the survival function method to characterize the water dynamics, and we show that different method combinations significantly affect the outcome. Our work strongly suggests that the fast water exchange kinetics around the calcium ions is not rate-limiting for reactions involving dissolved/solvated calcium. Our results further suggest that, for alkali and most of the earth alkali metals, mechanistic rate laws for growth, dissolution, and adsorption, which are based on the principle of rate-limiting cation dehydration, need careful reconsideration.

[ES] Un Centro de Mantenimiento Aeroáutico es una organización dedicada a la inspección, reparación, modi cación y realización de otros tipos de trabajo sobre las aeronaves para las cuales esté autorizada. La organización en la que se focaliza el proyecto es Cessna Spanish Citation Service Center, la cual trabaja sobre diversos modelos de Cessna y Beechcraft. Los procesos de mantenimiento aeronáutico son complejos, reglados y exigen de la m as alta calidad. Es por ello que una organización dedicada a ellos ha de buscar continuamente formas de mejorar la calidad y la productividad de sus procesos. El presente trabajo se centra en exponer las oportunidades de mejora que se han hallado en el centro de mantenimiento anteriormente nombrado y las medidas implementadas al respecto. Una atención especial merece la implementación del método MEDA para la investigación de eventos de mantenimiento, basado en la búsqueda en profundidad de los factores causantes del mismo a través de una entrevista con el personal involucrado., [EN] An Aircraft Maintenance Center is an organization dedicated to the inspection, repair, modi cation and accomplishment of other kind of works on the aircrafts which it is authorized for. This project is focused on Cessna Spanish Citation Service Center, a maintenance organization working with multiple Cessna and Beechcraf models. Aircraft maintenance procedures are complex, strictly regulated and high quality demanding. Because of this, any organization dedicated to them needs to continuously search for ways to improve the quality and the productivity in its processes. This project is focused on presenting the improvement oportunities that have been found in the previously mentioned maintenance center, and the implemented actions with respect to them. Special attention is put on the implementation of the MEDA methodology for the investigation of maintenance events, which is based on a deep research on the factors contributing to them by means of an interview with the involved crew.

La percepción y el reconocimiento de caras se ha estudiado con el fin de analizar la actividad cerebral en respuesta a este tipo de estímulos. Esta información es importante para el desarrollo de las interfaces cerebro-computadora y el estudio de los trastornos neurológicos. En este trabajo, se analizaron potenciales evocados como indicadores neurofisiológicos y desarrollamos un modelo basado en técnicas de procesamiento de señales y aprendizaje automático para encontrar patrones descriptivos que permitan la diferenciación de rostros familiares y no familiares. Consideramos componentes de onda como P1, N170, N250, P300 y N400 para describir los eventos. El análisis morfológico y la transformada wavelet se utilizaron para la etapa de extracción de características, y las máquinas de vectores de soporte y la regresión logística binomial se evaluaron para la etapa de clasificación. Los mejores resultados de clasificación se obtuvieron con las características morfológicas, donde la mayor precisión de clasificación fue del 80% en promedio.

The Colombian Biofuels Policy defines many aspects of biofuel production but whether the policy is feasible is not known. This paper takes a holistic view of the country-level production and distribution system to evaluate policy feasibility. We formulate the problem as a mixed-integer programming model and analyse the Colombian biodiesel policy given their current infrastructure, feedstock supply and demand. Model results provide several useful insights on how to design the overall system and also to support policy decision-makers. This paper contributes to the literature by analysing how the production-distribution network structure affects the cost and feasibility of biodiesel adoption.

Tracking multiple objects is a challenging problem for an automated system, with applications in many domains. Typically the system must be able to represent the posterior distribution of the state of the targets, using a recursive algorithm that takes information from noisy measurements. However, in many important cases the number of targets is also unknown, and has also to be estimated from data. The Probability Hypothesis Density (PHD) filter is an effective approach for this problem. The method uses a first-order moment approximation to develop a recursive algorithm for the optimal Bayesian filter. The PHD recursion can implemented in closed form in some restricted cases, and more generally using Sequential Monte Carlo (SMC) methods. The assumptions made in the PHD filter are appealing for computational reasons in real-time tracking implementations. These are only justifiable when the signal to noise ratio (SNR) of a single target is high enough that remediates the loss of information from the approximation. Although the original derivation of the PHD filter is based on functional expansions of belief-mass functions, it can also be developed by exploiting elementary constructions of Poisson processes. This thesis presents novel strategies for improving the Sequential Monte Carlo implementation of PHD filter using the point process approach. Firstly, we propose a post-processing state estimation step for the PHD filter, using Markov Chain Monte Carlo methods for mixture models. Secondly, we develop recursive Bayesian smoothing algorithms using the approximations of the filter backwards in time. The purpose of both strategies is to overcome the problems arising from the PHD filter assumptions. As a motivating example, we analyze the performance of the methods for the difficult problem of person tracking in crowded environments

Background: Acute dermatologic conditions are a concern for acute care practitioners. Comprising 1.4% of presenting complaints to emergency departments, most skin complaints are relatively benign; however, some conditions can be quite severe. Prompt diagnosis is essential to avoid unnecessary morbidity and mortality.Objectives: To review drug-induced vasculitis.Case Report: We present the case of a 43-year-old female with a chief complaint of bruising to her ear, arm, and leg. She was found to have necrotizing vasculitis induced by propylthiouracil.Conclusion: In this case, we look at the highlights of this presentation and review key aspects of cutaneous vasculitis for the practicing emergency provider.[WestJEM. 2008;9:212-215.]

DVB (Digital video broadcasting) is the television digital system. It's however much more than a simple replacement for existing analogue television transmission, this system has many advantages such as picture quality and allows you a range of new features and services including subtitling, multiple audio tracks, interactive content, multimedia content... The system is based in the OFDM technology, which allows DVB system to exploit the spectrum frequencies in a better way, saving spectrum, but OFDM has an important drawback that is the peak to average power ratio problem. OFDM is based on the FFT algorithms generating several orthogonal subcarriers. This thesis talks about the improvement of the PAPR problem using the clipping method. The simulation has been developed in Simulink® and Matlab®. With all the information presented in this thesis, any user can simulate the system. Thus, this thesis can be improved using other using other techniques to solve the PAPR problem.

Transcripts of community meetings conducted by the Institute of Texan Cultures as part of the Tejano Community Advisory Group.