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Polymer-Based Microstructured Photonic Membrane for Passive Heating Textiles
No full textInternational audienceThe development of textiles for personal thermal management is one of the most promising technological solutions to reduce the energy consumption in heating, ventilation, and air conditioning (HVAC) systems. These technologies offer a potentially low-cost solution that can help to limit greenhouse gas emissions. In this paper, we propose the design and fabrication of a polyimide (PI)-based microstructured photonic membrane (MSPM) for personal passive heating textile. Using a photolithographic process, the membrane is drilled with a triangular array of holes. We showed theoretically and experimentally that the MSPM can decrease the transmission of mid-infrared (MIR) radiation emitted by the human body. The thermoregulator effect of the MSPM is demonstrated by using a thermal camera and a thermocouple. This fabric can efficiently warm the human body, enabling lower room temperature while still maintaining personal comfort. Moreover, the microholes enable air permeability and promote water-wicking. The performance of this membrane provides a new opportunity to deploy thermal management textiles for everyday use and targets one of the major forms of energy consumption
19 mW/μm<sup>2</sup> and 24.5 % PAE at 94 GHz for 0.30-μm Transferred InP/GaAsSb DHBT on Si-HR
No full textInternational audienceInP HBT technology is a suitable candidate for the future 6G networks that require very high bandwidth. It has already demonstrated high-frequency operation with fmax exceeding 1 THz [1]. However, this performance comes at the cost of aggressive scaling which increases thermal resistance (Rth) due to device narrowing and leads to self-heating limiting overall performance. Transferring InP DHBT to a high-thermal-conductivity substrate has shown a drastic reduction of Rth by 65% on Si-HR [2] and 75% on SiC [3] thanks to their superior heat dissipation properties however its effect on output power remains unexplored. We present continuous wave (CW) large-signal load-pull measurements at 94 GHz of a transferred InP/GaAsSb DHBT transistor fabricated on a high-resistivity silicon substrate (HR-Si). The characterized device features an emitter area of 0.29×4.9μ m2 and was biased for both maximum output power and maximum power-added-efficiency (P.A.E). A peak output power of 14.25dBm(18,84 mW/μm2) was achieved. This result demonstrates the impact of thermal dissipation in reducing self-heating and enabling higher output power
Spectral Frequency Response of Hypersonic Phonons in a Non-Trivial Topological Waveguide
No full textInternational audienceThe spectral frequency response of a hypersonic phononic wave propagating along a non-trivial topological waveguide is obtained by laser Doppler vibrometry. The guided mode at 2.115 GHz is shown to propagate with minimal loss
Dans quelle mesure la culture nationale et les vécus culturels influencent-ils les motivations entrepreneuriales et les logiques managériales des entrepreneurs de différentes générations, issus de l’espace post-soviétique ?
No full textThis dissertation aims to study culture at the individual and collective levels in relation to generational motivations and entrepreneurship in the post-Soviet space. Applying generational concepts to entrepreneurship places emphasis on sociocultural values and phenomena. In times of disruption and transformation, individuals are particularly susceptible to the influence of significant social and emotional forces in their environment. During such periods, generational cohorts may be characterized by a particular entrepreneurial orientation that distinguishes them from previous generations. The persistence of generational cohorts is not automatic but rather depends on the collaboration and collective actions of the individuals within them. Overall, generational concepts offer a fruitful avenue for integrating sociohistorical and cultural context into entrepreneurship studies in a meaningful and multi-layered manner. The aim of this research is to outline an approach to the study of entrepreneurship that would identify ways in which generational concepts can enrich our understanding of entrepreneurial dynamics. By moving beyond purely demographic definitions of generations, this work aims to study the socio-historical and cultural dynamics that lead to meaningful collective representations, with high degrees of self-awareness and entrepreneurial identity as well as shared managerial logics.Le présent mémoire vise à étudier la culture au niveau individuel et collectif en lien avec les motivations et l’entrepreneuriat générationnel dans l’espace post-soviétique. En appliquant les concepts générationnels à l’entrepreneuriat, l’accent est mis sur les valeurs et phénomènes socio-culturels. En période de perturbation et de transformation, les individus sont particulièrement sensibles à l’influence d’importantes forces sociales et émotionnelles dans leur environnement. Dans de telles périodes les cohortes générationnelles peuvent être marquées par une orientation entrepreneuriale particulière qui les distingue des générations précédentes. La persistance des cohortes générationnelles n’est pas automatique mais dépend plutôt de la collaboration et des actions collectives des personnes qui les composent. D’une manière générale, les concepts générationnelles offrent une voie fructueuse pour intégrer le contexte socio-historique et culturel dans les études sur l’entrepreneuriat d’une manière significative et à plusieurs niveaux. Le but des recherches est d’esquisser une approche de l’étude de l’entrepreneuriat qui identifierait les façons dont les concepts générationnels pourront enrichir notre compréhension de la dynamique entrepreneuriale. En dépassant les définitions purement démographiques des générations, les présents travaux visent à étudier les dynamiques socio-historiques et culturels qui conduisent à des représentations collectives significatives, avec des degrés élevés de conscience de soi et une identité entrepreneuriale ainsi que des logiques managériales partagées
Energy minimizing capacitated covering vehicle routing problem
No full textInternational audienceThis paper introduces the Energy Minimizing Covering Capacitated Vehicle Routing Problem, which aims to minimize total energy consumed during delivery routes while satisfying customers’ demands. The problem considers a homogeneous fleet of identical vehicles stationed at a central depot and utilizes a concept of flexible delivery. Customers can receive parcels either directly during a vehicle visit or indirectly through designated neighboring customers. The flexible delivery can be particularly relevant for densely populated urban areas where parking is limited or situations where customers have restricted mobility or limited home presence. We formulate the studied problem as a mixed-integer programming problem. For large-scale instances, skewed and standard general variable neighborhood search heuristics are developed to tackle the problem efficiently. Extensive testing validates the model and assesses the effectiveness and efficiency of the proposed heuristics. The study also compares the skewed GVNS with metaheuristics of similar design, including GRASP and Iterated Local Search, to benchmark its performance. The results reveal that a skewed general variable neighborhood search heuristic is a viable approach for solving the problem, particularly for large-scale instances. Additionally, the study explores the trade-off between energy consumption and total travel distance. Results suggest that slight increases in travel distance can lead to significant energy consumption and CO2 emissions savings
Advancing wheat crop analysis: A survey of deep learning approaches using hyperspectral imaging
No full textInternational audienceAs one of the most widely cultivated and consumed crops, wheat is essential to global food security. However, wheat production is increasingly challenged by pests, diseases, climate change, and water scarcity, threatening yields. Traditional crop monitoring methods are labor-intensive and often ineffective for early issue detection. Hyperspectral imaging (HSI) has emerged as a non-destructive and efficient technology for remote crop health assessment. However, the high dimensionality of HSI data and limited availability of labeled samples present notable challenges. In recent years, deep learning has shown great promise in addressing these challenges due to its ability to extract and analysis complex structures. Despite advancements in applying deep learning methods to HSI data for wheat crop analysis, no comprehensive survey currently exists in this field. This review addresses this gap by summarizing benchmark datasets, tracking advancements in deep learning methods, and analyzing key applications such as variety classification, disease detection, and yield estimation. It also highlights the strengths, limitations, and future opportunities in leveraging deep learning methods for HSIbased wheat crop analysis. We have listed the current state-of-the-art papers and will continue tracking updating them in the following GitHubRepository.</div
Enhanced Performance of P3HT-Based Vertical Organic Diode Through Graphene Monolayer Integration
No full textInternational audienceAn experimental study has been conducted to explore the graphene monolayer influence on the electrical behavior of an organic diode based on poly(3-hexylthiophene) (P3HT). This polymer is deposited by spin-coating in a vertical diode configuration. A graphene monolayer was transferred from paper support film to an electrode contact. A current–voltage characterization (I–V) was performed via a glove box system under spikes. We found that graphene thin films play a significant role in improving the electrical response, such as current density and rectification ratio, which are multiplied by 20 and by more than 330, respectively. Additionally, the charge transport mechanism has been studied, and ohmic and the space charge limited current (SCLC) conduction behaviors were identified at low and higher voltages
solQHealer: Quantum Procedures for Rendering Infeasible Solutions Feasible: A Proof of Concept with the Maximum Independent Set Problem and 3-SAT
No full textInternational audienceOver the past decade, the usefulness of quantum annealing hardware for combinatorial optimization has been the subject of active debate. Although current analog quantum machines do not guarantee optimality, operating instead as heuristic solvers, the technology is evolving rapidly. Beyond performance alone, this emerging technologies offers fundamentally new approaches to problem-solving that are not readily accessible to classical exact methods particularly in dynamic environments or online optimization settings. This paper focuses on one such approaches: Reverse Quantum Annealing (RQA). Unlike classical exact methods, RQA allows the optimization process to begin from an initial infeasible solution by embedding it directly into the qubits' initial state. We leverage this capability by formulating problem constraints as penalty terms within Quadratic Unconstrained Binary Optimization (QUBO) models, thereby preserving infeasible solutions within the quantum search space. We propose iterative strategies that apply RQA in three distinct modes to rapidly repair infeasible solutions. These methods are evaluated on two well-known NP-hard problems: the Maximum Independent Set (MIS) and the 3-SAT problem. Our results demonstrate the effectiveness of RQA in steering infeasible configurations toward feasibility, offering B Samuel Deleplanque</div
Droit de propriété, liberté d'expression et proportionality washing
No full textInternational audience(Civ. 1re, 10 juill. 2024, no 22-23.247 et no 22-23.170, D. 2024. 1889, note T. Le Bars et T. Scherer ; Légipresse 2024. 412 ; ibid. 549, comm. J. Bocquet et R. Le Gunehec ; RD rur. 2024, no 10, étude 13, note G. Sebban