Implementation strategies for hyperspectral unmixing using Bayesian source separation

Bayesian Positive Source Separation (BPSS) is a useful unsupervised approach for hyperspectral data unmixing, where numerical non-negativity of spectra and abundances has to be ensured, such in remote sensing. Moreover, it is sensible to impose a sum-to-one (full additivity) constraint to the estimated source abundances in each pixel. Even though non-negativity and full additivity are two necessary properties to get physically interpretable results, the use of BPSS algorithms has been so far limited by high computation time and large memory requirements due to the Markov chain Monte Carlo calculations. An implementation strategy which allows one to apply these algorithms on a full hyperspectral image, as typical in Earth and Planetary Science, is introduced. Effects of pixel selection, the impact of such sampling on the relevance of the estimated component spectra and abundance maps, as well as on the computation times, are discussed. For that purpose, two different dataset have been used: a synthetic one and a real hyperspectral image from Mars.Comment: 10 pages, 6 figures, submitted to IEEE Transactions on Geoscience and Remote Sensing in the special issue on Hyperspectral Image and Signal Processing (WHISPERS

reuse study of sustainable wastewater in agroforestry domain of marrakesh city

The current work aims to perform a feasibility study of sustainable urban wastewater reuse in agroforestry domain of Marrakesh city in order to assess the environmental and the sustainability of urban wastewater reuse in agroforestry irrigation. To this end, wastewater physicochemical characteristics from Marrakesh full-scale wastewater treatment plant, soil physicochemical analysis and climate analysis were investigated. Finally, treated urban wastewater potential production in Marrakesh WWTP and challenge related to its reuse are provided. The obtained results of the present study reveals the feasibility of this practice in Marrakesh region. Regarding the actual situation, climate analysis highlight that the local climatic conditions is an ultimate challenge for water resources; soil analysis reveals a loss of soil fertility due to the decline in soil organic matter. To face this condition, treated urban wastewater reuse is a sustainable and promising strategy to face water scarcity, enhance soil fertility, preserve natural resources, develop local products and improve living conditions of agriculture and farmers. Keywords: Urban wastewater, Physicochemical analysis, Wastewater reuse, Climate analysis, Arid climate, Marrakes

مغاربة المهجر ورابط الانتماء، بين مقتضيات مدونة الاسرة واكراهات القانون الدولي الخاص

إن تحدي ضمان نجاح عملية اندماج المهاجر المغربي في الخارج، لا يمكن، في أي حال، إلقائها على عاتق الدول المستقبلة حصراً، فالدولة المغربية تتحمل قسطا من تلك المسؤولية، خصوصا عند حديثنا عن حماية رابط لانتماء من مختلف مظاهر التقطع. لعل النص القانوني ذو الصلة المباشرة بهذا الموضوع، لا يمكن أن يكون إلا مدونة الأسرة، بما تحيل إليه من تحديات قانونية وقضائية، نظراً للأهداف الملقاة على عاتقها والمتمثلة في الحفاظ على استقرار واستدامة الأسرة المغربية بكل مكوناتها، وحفظ حقوق أفرادها سواء ما كان ذي صلة بالأزواج أو ارتبط بالأبناء. بذلك، فإن هذه القراءة لا يمكن أن تعطي أكلها دون إقامة رابط بين النصوص القانونية والمقاربات السوسيولوجية المفسرة لها.The challenge of ensuring the success of the process of integrating Moroccan immigrants abroad can in no way rest exclusively on the shoulders of the host countries. an affiliate link from various logout events. Perhaps the legal text directly related to this subject can only be the Family Code, with its legal and judicial issues, given the objectives entrusted to it, which are to maintain the stability and sustainability of the family. Moroccan society with all its components, and to preserve the rights of its members, whether spouses or partners with children. Thus, this reading cannot bear fruit without establishing a link between legal texts and explanatory sociological approaches

Échantillonnage comprimé pour le diagnostic filaire par réflecométrie

National audienceLa réflectométrie est une technique utilisée en diagnostic filaire pour permettre la détection et la localisation de nombreux types de défauts des câbles. Alors que, les convertisseurs analogique-munérique (CAN) sont indispensables dans les architectures de la réflectométrie, la nécessité du respect de la condition de Shannon et le besoin d’effectuer des traitements en temps réel limitent les fréquences maximales des signaux injectés, et par conséquent la précision de localisation. La contribution de ce papier est d’étudier, pour la première fois, l’échantillonnage comprimé du signal réfléchi afin de s’affranchir des limites de Nyquist et d’économiser la mémoire de stockage. Pour cela nous utilisons un signal complexe sous forme de « chirp » linéaire et nous adoptons un dictionnaire induisant la parcimonie. Grâce à l’acquisition comprimée et son encodeur analogique nous arrivons à reconstruire le réflectogramme avec une fréquence d’éachantillonnage de huit fois mois élevée que celle de Nyquist

Admissible Almost Type Z-Contractions and Fixed Point Results

In this paper, we introduce a new concept of α-admissible almost type Z-contraction and prove some fixed point results for this new class of contractions in the context of complete metric spaces. The presented results generalize and unify several existing results in the literature

Optimisation itérative par majoration-minimisation pour l’estimation statistique sous l’hypothèse d’un bruit ricien

National audienceCette communication s’intéresse à l’estimation statistique d’un signal perturbé par un bruit ricien avec comme objectif de proposer un algorithme de débruitage efficace. L’application ciblée concerne le traitement d’images biologiques obtenues par résonance magnétique. Partant du constat que le critère à minimiser est unimodal mais non-convexe, la principale contribution de cette communication consiste en la proposition d’une stratégie d’optimisation fondée sur les techniques de majoration-minimisation (MM) quadratique apr`es introduction d’une transformation permettant la convexification du critère à minimiser. Le schéma de descente itérative proposé sera comparé à l’approche de descente MM de référence. Les performances sont analysées en utilisant des données réelles issues de l’analyse d’échantillons agroalimentaires

Primal-dual Interior-Point Optimization Based on Majorization-Minimization for Edge-Preserving Spectral Unmixing

International audiencePrimal-dual interior-point methods are used in image processing to solve inversion problems that can be reduced to constrained convex minimization. Such iterative methods require the solution of a sequence of positive definite symmetric linear systems which are used to derive descent directions. This approach is very consuming in terms of computing time and memory usage for large-scale problems, unless the normal matrices have a specific structure. This is the case in the spectral unmixing problem where the normal matrices are block-diagonal when no spatial regularization is considered. Here, we consider the spatially regularized case and we propose to tackle the linear system solving using a majorization-minimization (MM) approach based on separable quadratic majorant functions. The resulting systems have the same structure as in the non-regularized case and can thereby be solved efficiently. The interior-point algorithm is speeded-up while remaining convergent. An example of spectral unmixing is proposed to illustrate the efficiency of this approac

Insights into large landslide mechanisms in tectonically active Agadir, Morocco: The significance of lithological, geomorphological, and soil characteristics

Landslide susceptibility assessment is crucial for land use planning, infrastructure development, and hazard mitigation, particularly in tectonically active regions where lithology and soil characteristics significantly influence slope stability. This study aims to evaluate landslide susceptibility in the Agadir Ida-Ou-Tanane province, a tectonically active area, using a hierarchical multicriteria analysis approach. Eight factors influencing landslide occurrence were considered: lithology, slope, LULC, distance to main faults, hypsometry, drainage density, road density, and aspect. Pairwise comparison matrices and expert opinion were employed to determine the relative importance of these factors. The consistency ratio (CR) was calculated to ensure the reliability of the judgments. The resulting landslide susceptibility map reveals a spatial distribution ranging from very low to very high susceptibility zones. Lithology, mainly clay, and limestone formations, emerged as the most influential factor due to the active tectonic context of the study area. The model was validated using observed landslide locations and the Area Under the Curve (AUC) method, yielding a reasonable validation accuracy. The findings indicate that integrating these factors, with a particular emphasis on lithology and soil characteristics, effectively identifies areas prone to landslides, making the resulting map a valuable tool for land use planning and risk management in the Agadir Ida-Ou-Tanane region. This study contributes to understanding landslide susceptibility in tectonically active areas and provides a practical foundation for future research and decision-making. Regularly monitoring and updating the landslide susceptibility map is necessary to ensure its continued relevance and utility for stakeholders