715 research outputs found
Confluence of singularities of differential equation: a Lie algebra contraction approach
We investigate here the confluence of singularities of Mathieu differential
equation by means of the Lie algebra contraction of the Lie algebra of the
motion group M(2) on the Heisenberg Lie algebra H(3). A similar approach for
the Lam\'e equation in terms of the Lie algebra contraction of on
the Lie algebra of the motion group M(2) is outlined
Structural analysis of wind blades with and without power control
The blade is the principal element in the wind rotor mechanism. the efficiency of the wind turbine depends on the optimal geometry of this element, as well as its structural configuration. This work presents a contribution to wind blade structural design. the blade structure was evaluated without the control power operating case and with the power control case. In this case, an 80KW horizontal axis wind turbine design was proposed. the process begins with design and aerodynamic analysis based on blade element momentum theory by using Qblade software to determine the blade geometry. The blade structure was defined by the NuMad package, it is composed of two parts. the shell part is four layers of composite materials and the rib part has a sandwich panel shape. The evolution of structure was done by the Co-Blade package. The results show a decreasing in displacement decreased to 64% at the tip of the blades which leads to the stress at the leading and trailing edge being negligible. That proves the importance of a control power system in the protection of the blade structure and turbine generator in the operating case under high wind velocity and ensures the stability of the power output value
Asymmetric impact of patents on green technologies on Algeria's Ecological Future
This study examines how patents on green technologies impact Algeria's ecological footprint from 1990 to 2022 while controlling for economic growth and energy consumption. The objectives are to analyze the asymmetric effects of positive and negative shocks in these drivers on ecological footprint and provide policy insights on leveraging innovations and growth while minimizing environmental harm. Given recent major structural shifts in Algeria's economy, time series data exhibits nonlinear dynamics. To accommodate this nonlinearity, the study employs an innovative nonlinear autoregressive distributed lag approach. The findings indicate that an upsurge in green technologies (termed as a positive shock) significantly reduces the ecological footprint, thereby enhancing ecological sustainability. Interestingly, a decline in green technologies (termed as a negative shock) also contributes to reducing the ecological footprint. This highlights the crucial role of clean technologies in mitigating ecological damage in both scenarios. Conversely, a positive shock in economic growth increases ecological footprint, underscoring the imperative for environmentally friendly policies in tandem with economic expansion. Negative shocks, however, have minimal impact. In a similar vein, positive shock in energy consumption increases ecological footprint, underlining the importance of transitioning towards cleaner energy sources. Negative shock has a smaller but still noticeable effect. The results confirm asymmetric impacts, with positive and negative changes in the drivers affecting Algeria's ecological footprint differently. To ensure long-term economic and ecological stability, Algeria should prioritize eco-innovation and green technology development. This will reduce dependence on fossil fuels and create new, sustainable industries.</p
New kinds of deformed Bessel functions
15 pages, minor changes.Using a deformed calculus based on the Dunkl operator, two new deformations of Bessel functions are proposed. Some properties i.e. generating function, differential-difference equation, recursive relations, Poisson formula... are also given with detailed proofs. Three more deformations are also outlined in the last section
New kinds of deformed Bessel functions
15 pages, minor changes.Using a deformed calculus based on the Dunkl operator, two new deformations of Bessel functions are proposed. Some properties i.e. generating function, differential-difference equation, recursive relations, Poisson formula... are also given with detailed proofs. Three more deformations are also outlined in the last section
Asymmetric impact of patents on green technologies on Algeria's Ecological Future
This study examines how patents on green technologies impact Algeria's ecological footprint from 1990 to 2022 while controlling for economic growth and energy consumption. The objectives are to analyze the asymmetric effects of positive and negative shocks in these drivers on ecological footprint and provide policy insights on leveraging innovations and growth while minimizing environmental harm. Given recent major structural shifts in Algeria's economy, time series data exhibits nonlinear dynamics. To accommodate this nonlinearity, the study employs an innovative nonlinear autoregressive distributed lag approach. The findings indicate that an upsurge in green technologies (termed as a positive shock) significantly reduces the ecological footprint, thereby enhancing ecological sustainability. Interestingly, a decline in green technologies (termed as a negative shock) also contributes to reducing the ecological footprint. This highlights the crucial role of clean technologies in mitigating ecological damage in both scenarios. Conversely, a positive shock in economic growth increases ecological footprint, underscoring the imperative for environmentally friendly policies in tandem with economic expansion. Negative shocks, however, have minimal impact. In a similar vein, positive shock in energy consumption increases ecological footprint, underlining the importance of transitioning towards cleaner energy sources. Negative shock has a smaller but still noticeable effect. The results confirm asymmetric impacts, with positive and negative changes in the drivers affecting Algeria's ecological footprint differently. To ensure long-term economic and ecological stability, Algeria should prioritize eco-innovation and green technology development. This will reduce dependence on fossil fuels and create new, sustainable industries.</p
Neuro-Fuzzy Combination for Reactive Mobile Robot Navigation: A Survey
Autonomous navigation of mobile robots is a fruitful research area because of the diversity of methods adopted by artificial intelligence. Recently, several works have generally surveyed the methods adopted to solve the path-planning problem of mobile robots. But in this paper, we focus on methods that combine neuro-fuzzy techniques to solve the reactive navigation problem of mobile robots in a previously unknown environment. Based on information sensed locally by an onboard system, these methods aim to design controllers capable of leading a robot to a target and avoiding obstacles encountered in a workspace. Thus, this study explores the neuro-fuzzy methods that have shown their effectiveness in reactive mobile robot navigation to analyze their architectures and discuss the algorithms and metaheuristics adopted in the learning phase
Une approche critique du modèle dominant de prévention du risque chimique
Après un rappel des enjeux en œuvre dans le champ de la prévention du risque chimique, nous présentons les éléments fondateurs ainsi que l’évolution historique de la démarche ergotoxicologique. Cette démarche pluridisciplinaire vise à construire et à évaluer de nouvelles approches de prévention du risque chimique.Nous décrivons le modèle dominant de prévention du risque chimique en milieu de travail, que nous désignons par « modèle par écrans ». Nous proposons une lecture critique de chacun de ces écrans. Nous définissons ensuite l’ergotoxicologie et envisageons les perspectives de son développement.After a brief review of what is at stake in the field of chemical risk, we shall present the founding elements as well as the historic evolution of the ergo-toxicological approach. This multidisciplinary approach aims to devise and assess new perspectives on the prevention of chemical risks. We shall describe the leading model in terms of prevention of chemical risk in work, which we call the “screens model”. We shall then propose a critical review of each of the screens. We shall then define ergo-toxicology and consider its future development.Tras realizar un recordatorio de lo que esta en juego en el marco de la prevención del riesgo químico, presentaremos los elementos fundadores, así como la evolución histórica de la aproximación ergo toxicológica. Este enfoque pluri-disciplinar intenta construir y evaluar nuevos enfoques en la prevención del riesgo químico.Describiremos el modelo dominante de prevención del riesgo químico en el medio laboral, modelo que denominamos “modelo por pantallas”. Proponemos una lectura crítica de cada una de estas pantallas. Definimos luego la ergo toxicología y consideramos las perspectivas de su desarrollo
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