Endurance Track: A Comprehensive Embedded System for Equestrian Endurance Race Management

Digital transformation in horse businesses occurs by providing software and hardware solutions to virtually assist the stables’ everyday operations. In this paper, we propose a system that aims to help the Equestrian Federation in Bahrain hold all the things related to endurance races in Bahrain and during international competitions. It consolidates all of the information about the horses, stables, and stakeholders into one system. It centralizes horse, stable, and stakeholder data. A smart wearable horse health monitoring device uses Internet of Things sensors like a heart rate (HR) sensor to assess the horse’s HR throughout the race and inform the horse responsible if the horse is in an abnormal condition. The GPS module tracks each horse on a racing track-customized map. Arduino Node-MCU controls GPS and HR and uploads HR and GPS data to the Firebase Database. Horse, race data, and results will be stored in a Firebase real-time database and accessible via a Flutter-developed mobile app. The device stores the QR code affixed by the federation to each horse’s passport for identification purposes, thereby facilitating the digital identification of horses. The system will improve endurance race quality quickly by simplifying registration, tracking horse health, and reducing human work

Higher education in the era of artificial intelligence: academic freedom as a case study

International audienceHigher education is crucial for the development of states and societies and improving the overall quality of life. However, entry into higher education is often influenced by factors beyond qualifications, and individuals in the field face suppression from the controlling parties. These challenges undermine the value of education and the integrity of democratic processes like elections. In this paper, we study academic freedom in Lebanon and propose a technique that dynamically extracts the factors that might affect academic freedom. This technique comprises multiple stages: data collection, data preprocessing, static extraction of factors, dynamic extraction of factors, and evaluation. In the data collection stage, data was obtained from 254 participants through a questionnaire that discusses various facets of academic freedom. The preprocessing stage enhances data quality through cleaning, normalizing, and transforming. For static extraction, factors impacting academic freedom are identified using naive K-means clustering. In dynamic extraction, the Apriori algorithm identifies key metrics. Finally, a customized K-means algorithm clusters data based on a specific metric. This algorithm was applied on both, the statically and dynamically extracted metrics, and comparison was done based on the accuracy of the resultant clustering. This comparison demonstrates the effectiveness of the proposed technique in identifying and analyzing factors impacting academic freedom

High Efficiency Class-B power amplifier with dynamic gate biasing for improved linearity

International audienc

Conception d'un amplificateur de puissance à 2 étages intégrant une préformation de la tension de commande d'entrée

National audienceCe papier présente une technique damélioration du rendement en puissance ajoutée (PAE) dun amplificateur GaN par la préformation de la tension de commande de grille du transistor. Cette étude est effectuée à la fréquence de 2 GHz en utilisant des transistors GaN 15W de la fonderie CREE. Lamplificateur de puissance à 2 étages présente un rendement en puissance ajoutée (PAE) de 72% associé à une puissance de 41.8 dBm à 3dB de compression de gain à la fréquence centrale. Cet amplificateur comprend un étage de puissance fonctionnant en classe F et un étage driver spécifique pour réaliser une préformation de la tension de commande dentrée de létage de puissance. Cette technique permet dobtenir de bonnes performances en rendement sur une bande de fréquence assez large, ce qui constitue une difficulté majeure dans le domaine de lamplification de forte puissance. Dans le cas présenté une valeur de PAE supérieure à 60% est obtenue sur 25% de bande avec une puissance de sortie maintenue à 15 W

Experimental study on effect of second-harmonic injection at input of classes F and F-1 GaN power amplifiers

International audienceThis presented study focuses on the impact of gate-source voltage waveforms on power added efficiency performances of GaN HEMTs for the design of class F and class F-1 amplifiers. It is shown that second-harmonic signal injection at the gate port of transistors can lead to efficiency improvements in the case of class F operation and efficiency deteriorations in the case of class F-1 operation. This work is applied to a 15 W GaN HEMT die from Cree at a fundamental frequency Fo equal to 2 GHz. Calibrated on-wafer time domain measurements are reported

Analyse comparative des classes en commutation (F, F-1, E) pour l'amplification de puissance en technologie GaN

National audienceCette étude est effectuée en bande L à 1.5GHz (pour les applications spatiales) avec un modèle de transistor GaN 10W de la fonderie Eudyna. L'amplificateur optimisé en classe F présente un rendement en puissance ajoutée (PAE) de 72% associé à une puissance de 40.3dBm à 2dB de compression de gain. Pour celui optimisé en classe F-1, on obtient 74.5% de PAE et une puissance de 42.6dBm à 5dB de compression. Lors de l'analyse en classe E, on obtient 75% de PAE et une puissance de 41.1dBm à 3dB de compression de gain. La classe E apparaît alors comme la classe la mieux adaptée pour un compromis optimal en rendement et en puissance

Efficiency Enhancement of GaN Power Amplifiers over Wide Bandwidth by an Active Control of Gate Source Waveforms

This paper presents a technique to improve the power added efficiency (PAE) of GaN power amplifiers by an appropriate shaping of the gate source voltage waveform. High efficiency performances of microwave power amplifiers are reached by implementing proper matching conditions at harmonic components. For microwave applications, harmonic tuned amplifiers offer for the moment the best energy conversion efficiency between DC supply and RF power at fundamental frequency available in a 50 load.[1] In addition to proper harmonic terminations, the minimization of power losses at fundamental frequency in the output RF matching and power combining circuit is of prime importance. This has been widely reported over the past few years. Considering this main aspect GaN technology offers an evident advantage due to its high drain voltage operation capability that is beneficial for designing low loss and wideband output matching circuits. Several works have been reported during the past few years.[2],[3],[4],[5],[6] A problem encountered when designing high efficiency power amplifiers is to avoid getting high efficiency performances restricted to only a narrow frequency bandwidth around center frequency. It can be often observed that the higher the PAE is at center frequency, the quicker the PAE decreases at offset frequencies each side away from the center frequency. This can be attributed to high Q resonant tuning conditions. We point out and examine in this paper a major role played by the gate source voltage waveform in PAE performances over a frequency bandwidth of interest. For power amplifiers operating at saturated power, a significant second harmonic current component exists at the gate port and is terminated into a passive resonant circuit like for example a quarter wave length line used in the gate bias circuit. For offset frequencies, phase conditions of the passive source impedance at second harmonic vary and lead to non appropriate enlarged gate source voltage waveform upper the pinch off value.That leads to larger turn on time of the drain current resulting in a larger overlapping between drain current and drain voltage prejudicial for dissipated power and power added efficiency. In this paper we present a solution to maintain an appropriate gate source voltage shape. It consists in driving the gate of a power stage with an appropriate half sine voltage shape supplied by a driver stage operating at low drain bias voltage

Two Stage GaN HEMT Amplifier With Gate Source Voltage Shaping for Efficiency Versus Bandwidth Enhancements.

International audienceIn this paper a two-stage 2-GHz GaN HEMT amplifier with 15-W output power, 28-dB power gain, and 70% power-added efficiency (PAE) is presented. The power stage is designed to operate under class F conditions. The driver stage operates under class F-1 conditions and feeds the power stage with both fundamental and second harmonic components. The inter stage matching is designed to target a quasi-half sine voltage shape at the intrinsic gate port of the power stage. The goal is to reduce aperture angle of the power stage and get PAE improvements over a wide frequency bandwidth. In addition to the amplifier design description, this paper reports original time-domain waveform measurements at internal nodes of the designed two-stage power amplifier using calibrated high-impedance probes and large signal network analyzer. Furthermore, waveform measurements recorded at different frequencies show that aperture angle remains reduced over large frequency bandwidth. In this study, a PAE greater than 60% is reached over 20% frequency bandwidth

Study and Design of High Efficiency Switch Mode GaN Power Amplifiers at L-band Frequency

International audienceActivities have been carried out to determine the best electrical operating conditions of GaN HEMT that enable maximum power added efficiency at L-Band for Switch Mode Power Amplifiers (class F, inverse class F and class E). Satellite Radio navigation applications (Galileo) are targeted. Maximization of power added efficiency is of prime importance to save DC power consumption, reduce self heating effects and improve reliability of power amplifiers. At 50V drain bias, a maximum power added efficiency (PAE) of 72% and 40.3 dBm output power (Pout) are obtained using class-F operating conditions at 2dB gain compression while a 75% PAE and 41.0 dBm Pout are obtained using class E at 3dB gain compression