Scientific Publications of the University of Toulouse II Le Mirail
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Insights into Oxygen Vacancy Effects on Ferroelectric Behavior of Hafnium Oxide: A Review
No full textInternational audienceFerroelectricity in hafnium oxide thin films has become a scalable and silicon‐compatible solution for nonvolatile memory and logic applications. The orthorhombic ferroelectric phase, while metastable, becomes accessible through oxygen vacancies, which play a complex role in enabling and degrading device performance. Controlled vacancy incorporation can stabilize polarization and enhance endurance, while uncontrolled migration under an electric field leads to wake‐up effects, fatigue, imprint, and leakage. This review examines how oxygen vacancies influence ferroelectric phase formation, switching behavior, and reliability in hafnium oxide systems. First‐principles simulations reveal that vacancy charge states modulate phase energetics and dipole formation. Experimental methods—including X‐ray photoelectron spectroscopy, electron paramagnetic resonance, and electron energy loss spectroscopy—offer insight into vacancy distributions at the atomic scale. Vacancy behavior is linked to remnant polarization stability and switching degradation at the device level. Process strategies such as dopant engineering, thermal annealing, and interface design are shown to be critical for vacancy control. A deeper understanding of vacancy dynamics, combined with in situ characterization and predictive modeling, is essential for advancing hafnium oxide‐based ferroelectric memories and neuromorphic architectures
Une "république toulousaine" ? Réflexions autour de l’émancipation du consulat de Toulouse (v. 1152-v. 1205)
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Alternance syntaxique des verbes psychologiques en français: expérient en premier !
No full textInternational audienceFrench transitive psych-verbs with an experiencer object (such as étonner ‘to surprise’) occur more frequently in the passive voice than the active voice in oral corpora (Blanche-Benveniste 2000, Hamma et al. 2017). This observation is in line with Ferreira’s (1994) hypothesis that the experiencer, being more prominent than the stimulus, tends to align with subject function. Using sentence recall (Tanaka et al. 2011), we collected experimental data to test Ferreira’s hypothesis in French, and to evaluate a competing hypothesis: given that the experiencer is always animate, using the passive voice for experiencer-object psych-verbs reflects the tendency to align subjects with animate referents (da Cunha & Abeillé 2020 2022, Thuilier et al. 2021). We manipulated two intra-item variables –stimulus animacy and voice – and one inter-item variable – semantic role of the direct object. The experiment included 12 items with exp-DO verbs ('épouvanter') and 12 items with stim-DO verbs ('apprécier'). Other variables (length, definiteness) were controlled to favor the passive structure, considered to be the rare alternate. All along the trial, a defense witness appreciated {the atmosphere/the magistrate}.The experiment was organized into 24 blocks of 4 sentences, each containing one experimental item. For each block, participants were exposed to 4 sentences successively with the instruction to memorize them. After a distraction task, the primes (in bold in the examples) from the 4 sentences were presented sequentially, and participants were asked to recall aloud the target sentence from the prime. The responses of the 141 participants were recorded, transcribed and sorted according to whether they were correctly recalled and whether they showed voice inversion. Inversion rates show that participants tend to change the voice to align the experiencer with the subject function. When there is an asymmetry of animacy (animate experiencer / inanimate stimulus), the probability of having the experiencer as subject significantly increases. The two competing hypotheses are, in fact, complementary: the effect of animacy is added to the effect of argument prominence. The statistical analysis (mixed-effects logistic regression with participants and items as random effects) confirms the observations: an animate stimulus disfavors inversion (coef. -0.65, p<.0001) and the interaction between the active structure and the Exp-DO verbs strongly favors inversion (coef. 1.77, p<.0001). Our results highlight the value of experimental approaches for the study of syntactic alternations and call for cross-linguistic comparisons of the argument structure effects of psych-verbs in voice alternations
Information visualization for supporting short-term and long-term situation awareness in ground segments monitoring: application to SWOT command and control operations
No full textInternational audienceThe CNES-funded project called STRECCC (STudy and Recommendations for the Ergonomics of Command and Control Centers) studies ground segment interactive applications, their user interfaces, and how the controllers interact with them, to identify solutions ensuring the usability of future, more automated command and control centers. The nature of the operations evolves, along with the skills, knowledge, and expertise of controllers. Their profile evolves being less technical and with less knowledge in the underlying systems or telecommunications. The STRECCC project addresses these evolutions by designing advanced user interfaces improving performance and situation awareness of the controller. The designs deeply exploit knowledge and research contributions in the area of information visualization and Human-Computer Interaction. In this paper, we present the approach, based on task models, we applied to investigate the usability of the SWOT Control and Command Center (CCC). Based on the study we performed, we present two prototypes of interactive visualizations to enhance operations by improving the perception and understanding of numerous information while performing different types of tasks (e.g., identifying a disconnected antenna, comparing the processing state of two telecommands …). From the results of a predictive evaluation and preliminary empirical feedback, they improve the situation awareness of the controllers by providing a long-term (a full week) perspective on recent-past and future operations
S’approprier les règles du métier grâce à divers contextes d’expérience: L'appropriation d'une règle de métier :une articulation de contextes formels, non formels et formels par l'expérience
No full textInternational audienceCet article propose d’appréhender comment l’appropriation de prescriptions culturelles de métier se construit chez des enseignants stagiaires en formation professionnelle en étudiant diverses expériences vécues dans des contextes formels, non formels ou informels. Nos résultats suggèrent que l’appropriation de règle de métier se bâtit de façon différenciée chez les enseignants stagiaires, par tâtonnements et en articulant les expériences vécues dans ces différents contextes. (« Varia »)
More birational involutions
No full textFor S a very general polarized K3 surface of degree 8n -6, we describe in geometrical terms a birational involution of the Hilbert scheme S [n] of n points on the surface, whose existence was established in [8] from lattice theoretical considerations. In [9] we studied this involution for n = 3 with the help of the exceptional Lie group G2, since the Mukai model of S is embedded in its projectivized Lie algebra. Here we use different, more general arguments to show that some important features of the birational involution persist for n ≥ 4. In particular we describe the indeterminacy locus of the involution in terms of a Mori contraction, and deduce that it is birational to a P2 -fibration on a moduli space of sheaves Σ on S, that also admits a degree two nef and big line bundle and an induced birational involution
Evaluation of Different Group Formation Methods in the Context of Distributed Pair Programming: Design and Experiment in Higher Education
No full textInternational audienceGroup formation is an important issue in collaborative learning, as properly formed groups can lead to better interactions between students and enhance their learning. This issue also applies to pair programming when it is used as a learning activity. When the number of students is important and/or students and teachers do not know each other very well, manual group formation, either by students or teachers, can become difficult. Many of the existing automatic methods used for automatic group formation in pair programming require a certain amount of personal information about the students, which can make the implementation of this kind of system difficult. Hence, in this paper we present an automatic pair formation method integrated to a distributed pair programming application. Our approach is based on personal data from the students collected with questionnaires within our platform, but also on trace data automatically collected from the pair programming activities completed by students. It has been experimented during an introductory programming course in higher education. The objective was to identify, among programming experience, self-efficacy, gender and past engagement in pair programming activities, the formation criteria that led to the best perceived compatibility and work distribution as well as performance. The results show that homogeneous pairs in self-efficacy are significantly better than heterogeneous pairs, both in terms of perceived compatibility and perceived work distribution
Le cartulaire des Trencavel (Languedoc, XIe-XIIIe siècle)
No full textInternational audienceThe 'cartulaire des Trencavel' is undoubtedly the oldest secular cartulary in the Kingdom of France, and perhaps even in the medieval West.It was compiled in two stages, around 1186-1188 and then around 1203-1206, by notaries acting on behalf of this dynasty, which ruled over six viscounties: Albi, Carcassonne, Razès, Béziers, Agde and Nîmes. Comprising 260 folios, it includes 586 different deeds, 134 of which were only known from modern manuscript copies and 161 of which are entirely unpublished. The texts are written in Latin or Occitan, and some of them feature an interesting alternation between the two languages. This first complete edition therefore offers a wealth of information on the workings of Languedoc feudal society, on fiefdoms, vassalage and homage, and on the countless castles and aristocratic lineages that owned them.Le cartulaire des Trencavel est sans doute le plus ancien cartulaire laïc du royaume de France, et peut-être même de l’Occident médiéval.Il a été compilé en deux temps, vers 1186-1188 puis vers 1203-1206, par des notaires agissant pour le compte de cette dynastie qui était à la tête de six vicomtés, Albi, Carcassonne, Razès, Béziers, Agde et Nîmes. Composé de 260 folios, il comprend 586 actes différents, dont 134 n’étaient connus que par des copies modernes manuscrites et 161 sont entièrement inédits. Les textes sont rédigés en latin ou en occitan, et certains d’entre eux présentent une intéressante alternance entre les deux langues. Cette première édition intégrale offre donc une masse d’informations sur les modalités de fonctionnement de la société féodale languedocienne, sur le fief, la vassalité et l’hommage, sur les innombrables châteaux et les lignées aristocratiques qui les détenaient
Reliable multi-RAT connectivity in urban V2X architectures: An experimental campaign
No full textInternational audienceThe future of smart cities relies on the quick and reliable exchange of contextual information between devices. Deploying access points at the edge of the network significantly reduces the propagation distance of sidelink messages, resulting in very low latencies. However, urban environments pose significant challenges, as numerous obstacles can block direct links between devices and their intended destinations. While the typical fallback solution is cellular connectivity, the difference in performance is substantial. To address this, the present work puts forward solutions for improved reliability in multiple Radio Access Technology urban vehicular architectures. On the one hand, we address situations where multiple links are available, by establishing a make-before-break vertical handover scheme for optimized radio interface selection, monitoring the performance of received packets. On the other hand, we also reflect on the situations where communication ranges are shortened, and thus propose a method where packets sent via Cellular-Vehicle-to-Everything (C-V2X) sidelink are relayed. Here, the initial message is received by an intermediary with better connectivity to the target access point and then retransmitted from this improved position. These solutions have yet to be studied in real-life urban testbeds. We thus present experimental campaigns aimed at exploring the performance and reliability of such communications in urban V2X architectures, exploiting C-V2X, 5G, autonomous vehicles and state-of-the-art hardware. We study multiple scenarios, extending or shortening line-of-sight situations to analyze coverage and performance. Performance analysis of our vertical handover solution shows a reduced usage of cellular connectivity, leading to a 27% reduction of packet latency. Then, relayed C-V2X packets show high reliability at up to 200-meter ranges from one peer to another, with observed latencies being, at worst, 42% more favorable than the cellular fallback