Mahsa A. Golkar

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This paper presents our new method, Short Segment- Structural Decomposition SubSpace (SS-SDSS), for the estimation of dynamic joint stiffness from short data segments. The main application is for datasets that are only piece-wise stationary. Our approach is to (i) derive a data-driven, mathematical model for dynamic stiffness for short data segments, (ii)(More)
Joint stiffness has been extensively used to study joint biomechanics. It can be described by a block-oriented, nonlinear, parallel-cascade structure under quasi-stationary conditions defined by the joint operating point. The model parameters are modulated dramatically during functional tasks where the joint operating point is varied with time. This paper(More)
The dynamic relationship between the joint position and reflex EMG in ankle muscles of healthy human subjects was studied for time-varying (TV) contractions. A linear parameter varying (LPV) identification algorithm was used to estimate the Hammerstein system relating ankle position to the reflex EMG response. The estimated Hammerstein system comprised a(More)
Dynamic joint stiffness is a dynamic, nonlinear relationship between the position of a joint and the torque acting about it, which can be used to describe the biomechanics of the joint and associated limb(s). This paper models and quantifies changes in ankle dynamic stiffness and its individual elements, intrinsic and reflex stiffness, in healthy human(More)
This paper proposes a complete distributed model for investigating both the induced shaft voltage and bearing current in turbo generators due to the interaction with their static excitation systems. This affects the insulations gradually, leading to a possible electrical discharge current when the shaft voltage exceeds the dielectric breakdown voltage level(More)
The dynamic relationship between surface EMG (sEMG) and torque can be estimated from data acquired while subjects voluntarily modulate joint torque. We have shown that for such data, the input (EMG) contains a feedback component from the output (torque) and so accurate estimates of the dynamics require the use of closed-loop identification algorithms.(More)
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