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DE LA RESPONSABILITÉ DES ENTREPRENEURS ET DES INGÉNIEURS-ARCHITECTES EN MATIÈRE DE CONSTRUCTION D'USINES, DE BARRAGES ET D'INSTALLATIONS
No full textAlgorithms and communication: A systematized literature review
No full textLa influencia de los algoritmos en la sociedad es cada vez mayor a través de una presencia creciente en todos los ámbitos de la vida diaria, sin que seamos conscientes de ello y, en ocasiones, usurpando la identidad de otros actores sociales. El artículo tiene como propósito principal abordar la metainvestigación sobre el campo de la inteligencia artificial y la comunicación, desde una perspectiva holística que permita analizar el estado de la investigación académica, así como los posibles efectos en estas dos áreas y en la convivencia en un sistema democrático. Para ello se lleva a cabo una revisión sistematizada de la literatura reciente desde enfoques cuantitativos y cualitativos. La temática analizada es cambiante y novedosa; incluye el impacto y la interacción de algoritmos, bots, procesos automatizados y mecanismos de inteligencia artificial en el periodismo y la comunicación, así como su efecto en la democracia. Los resultados dibujan una producción científica en expansión, mayoritariamente en inglés, basada en la discusión teórica o centrada en la percepción de los profesionales de la comunicación. El objeto de estudio mayoritario se sitúa en el periodismo y en la democracia, con menor implicación de la ética o la educación. Los estudios señalan un gran interés sobre los efectos del uso de algoritmos sobre el periodismo y la democracia, pero las respuestas son todavía inciertas y los retos para los próximos años importantes
Study on the Annular Pressure Prediction Method for Ultra-Deep Well Hydraulic Lift Dual-Gradient Drilling
No full textWith the ongoing advancement of oil and gas exploration into deep and ultra-deep formations in China, precise wellbore pressure control under complex geological conditions has become a critical technical challenge for safe drilling operations. To overcome the limitations of existing dual-gradient drilling (DGD) technologies—particularly their poor applicability and limited pressure regulation capability in land-based drilling—this study introduces an innovative hydraulic-lift dual-gradient drilling annular flow model, tailored for ultra-deep vertical wells. The model accounts for solid–liquid phase separation flow characteristics and the hydraulic-lift effect of downhole dual-gradient pumps. The Stability Enhancing Two-Step (SETS) method is employed to solve the strongly nonlinear, coupled governing equations, significantly improving computational stability and efficiency. Experimental validation reveals that the model’s predicted pressure distribution closely matches measured data, with a maximum average error of only 16.4%, confirming the model’s accuracy and applicability. Additionally, this study systematically analyzes the impact of key parameters—such as drilling fluid flow rate, viscosity, lift pump speed, and the number of pump sections—on bottomhole pressure regulation, providing valuable insights into their influence on annular pressure behavior. The findings offer a solid theoretical foundation for optimizing drilling parameters and ensuring safe, efficient drilling in ultra-deep wells under challenging geological conditions.OPEN ACCESS Received: 16/07/2025 Accepted: 19/08/202
MTNet: Multi-Task Underwater Image Enhancement Method Based on Retinex
Get PDFUnderwater images play a critical role in underwater exploration and related tasks. However, due to light attenuation and other underwater factors, underwater images often suffer from color distortion and low contrast, which to some extent limit the efficiency and safety of underwater exploration. To meticulously address these issues and enhance the accuracy and reliability of underwater exploration, this paper proposes a multi-task underwater image enhancement method based on Retinex theory. This method divides the underwater image enhancement task into several sub-tasks, including image decomposition, color correction, detail reconstruction, and illumination adjustment. Specialized sub-networks— DecomNet, DecolorNet, and DelightNet—are designed to specifically address these problems, thereby alleviating color distortion, enhancing image details, and improving contrast. Experiments conducted on several publicly underwater image datasets indicate that the quality of underwater images is significantly improved after enhancement with the proposed method, compared to other representative underwater image processing techniques. For example, on the real-world dataset Underwater Image Enhancement Benchmark, the MSE, Structural Similarity Index Measure, and Peak signal-to-noise ratio scores achieved were 453.480, 0.901, and 25.145, respectively. This study holds significant implications for underwater exploration, with potential applications in the fields of marine research and underwater archaeology.OPEN ACCESS Received: 03/11/2024 Accepted: 27/12/2024 Published: 20/04/202
On the influence of ply thickness and staking sequence in the Free-edge effect
No full textThe edge effect in composite materials is a phenomenon associated with the anisotropy of these materials, generating interlaminar shear and tensile stresses and delaminations at the edges of the panels. This fact was studied by Pipes and Pagano in 1973, obtaining a solution to solve the problem with certain application limitations. This document aims to show a solution to the problem based on the studies carried out since then and use a method capable of evaluating these interlaminar forces, as well as a preliminary failure criterion associated with it. Different parameters can be evaluated such as the thickness of the sheets, the combination of materials or different laminate sequences
Advancing seismic resilience: an innovative performance-based methodology for evaluating bridge seismic performance with soil-structure interaction considerations
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