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Abstract: This review focuses on control strategies for robotic ankle systems in active and semiactive lower-limb orthoses, prostheses, and exoskeletons. Special attention is paid to algorithms for gait phase identification, adaptation to different walking conditions, and motion intention recognition. The relevant aspects of hardware configuration and hardware-level controllers are discussed as well. Control algorithms proposed for other actuated lower-limb joints (knee and/or hip), with potential applicability to the development of ankle devices, are also included. [Copyright &y& Elsevier]

Abstract: This paper presents an adaptive observer to simultaneously estimate the parameters and states in a shear structure with an energy-dissipation device. The proposed scheme allows the closed-loop reconstruction of floor displacements and velocities through acceleration and force measurements. An important feature of the proposed scheme is that it does not require a canonical representation nor a state transformation, common design requirements in other adaptive schemes that lead to the estimation of non-physical variables. Sufficient conditions for stability are given via a matrix inequality. The design is illustrated with experimental results gathered with a reduced-scale five-story structure with a magneto-rheological damper. [Copyright &y& Elsevier]

Water is a common resource shared by many agents or farmers in irrigation districts, where water management is, therefore, a very complex problem if the target is the equitable distribution of resources or the efficient use of water. This paper aims to present the design and implementation of an Irrigation Agent-Based Model (IABM) for the distribution of water in an irrigation district. In the IABM proposed, each field or farm can be considered as a micro-level and a region or irrigation district as a macro-level. The most approximated irrigation scheduling at each micro-level allows determining the water needs at the macro-level, as a reference for the negotiation of water distribution. A Geographical Information System (GIS) was used to manage georeferenced field information. Field capacity and permanent wilting point values, initial soil moisture, crop types, crop coefficients, root depth, sowing dates and weather data were incorporated into the IABM model for determining irrigation prescriptions. When water available in the irrigation district is insufficient to supply water requirements of all the irrigation fields, the IABM allows water distribution among them according to the cultivated field sizes, irrigation priorities, phenological states and the behavior of neighbors. When water resources are distributable, the proposed negotiation algorithm ensures that fields will use irrigation prescriptions defined with technical and agronomic criteria, thus avoiding the waste of water resource. The IABM developed meets the satisfaction requirement of the greatest number of agents by avoiding as much as possible that the soil water stress increases, using 25% of permissible level of moisture depletion respect to the total available water in each field. • An Agent-Based model (ABM) was implemented for negotiation of water in an irrigation district. • The irrigation ABM was made up of the perception, negotiation and satisfaction algorithms. • Agent behavior was influenced by the agent own interests, but also by their neighbors. • The soil water stress coefficient was used for implementing the satisfaction algorithm. [ABSTRACT FROM AUTHOR]

Abstract: In this study we have investigated the interaction of M@C60 (M=H, Li, Na, K, Be, Mg, Ca) with a (16,0) Zigzag SWNT using Density Functional Theory (DFT) calculations. The calculations reveal that in all the computed cases the metallo-endofullerene M@C60 complexes with the nanotubes are more stable than without internal cation species. Structural, electronic, vibrational and energetic descriptions of various fullerene–SWNT frameworks will also be shown and discussed. The physical nature of the interaction has been addressed and potential applications discussed. [Copyright &y& Elsevier]