Guilherme Aramizo Ribeiro

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This paper describes the protocols and results of the experiments for the estimation of the mechanical impedance of the humans' lower leg in the External-Internal direction in the transverse plane under non-load bearing condition and with relaxed muscles. The objectives of the estimation of the lower leg's mechanical impedance are to facilitate the design(More)
This paper describes the design of an ankle-foot robotic prosthesis controllable in the sagittal and frontal planes. The prosthesis was designed to meet the mechanical characteristics of the human ankle including power, range of motion, and weight. To transfer the power from the motors and gearboxes to the ankle-foot mechanism, a Bowden cable system was(More)
We compute the quantum correlation [quantum discord (QD)] and the entanglement (EOF) between nearest-neighbor qubits (spin-1/2) in an infinite chain described by the Heisenberg model (XXZ Hamiltonian) at finite temperatures. The chain is in the thermodynamic limit and thermalized with a reservoir at temperature T (canonical ensemble). We show that QD, in(More)
An underwater glider named ROUGHIE (Research Oriented Underwater Glider for Hands-on Investigative Engineering) is designed and manufactured to provide a test platform and framework for experimental underwater automation. This paper presents an efficient multi-level motion controller that can be used to enhance underwater glider control systems or easily(More)
This paper, for the first time, describes the estimation of the time-varying impedance of the human ankle in the sagittal (SP) and frontal (FP) planes during the stance phase of walking. The result of this work is aimed to provide design parameters for the development of 2-DOF powered ankle-foot prostheses capable of mimicking the time-varying impedance of(More)
We formulate the algebraic Bethe ansatz solution of the SU(N) vertex models with rather general non-diagonal toroidal boundary conditions. The reference states needed in the Bethe ansatz construction are found by performing gauge transformations on the Boltzmann weights in the manner of Baxter [1]. The structure of the transfer matrix eigenvectors consists(More)
This paper describes the methods and experiment protocols for estimation of the human ankle impedance during turning and straight line walking. The ankle impedance of two human subjects during the stance phase of walking in both dorsiflexion plantarflexion (DP) and inversion eversion (IE) were estimated. The impedance was estimated about 8 axes of rotations(More)