Sang Hoon Kang

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> It has been reported that, in impedance control, there exists a dilemma between impedance accuracy and robustness against modeling error. As a solution to this dilemma, an accurate and robust impedance control technique is developed based on internal model control structure and time-delay estimation: the former injects desired impedance and corrects modeling error, the latter estimates and compensate

Nanofiltration (NF) was investigated as an alternative to desalting electrodialysis (ED) and ion exchange for the recovery of ammonium lactate from fermentation broth. Three commercial NF membranes, NF45, NF70, and NTR-729HF, were characterized with 50 mM NaCl, MgSO(4), and glucose solutions. NF45 membrane was selected because it showed the lowest rejection of monovalent ion, the highest rejection of divalent ion, and the highest rejection of nonpolar molecule. Effects of the operating pressure

We investigated differences in knee kinetic variables (external knee adduction, flexion, internal rotation moments, and impulses) between patients with knee osteoarthritis (KOA) and healthy controls during stepping on a custom elliptical trainer; and searched knee kinetic variable candidates for real-time biofeedback and for complementing diagnosis/evaluation on the elliptical trainer based on the knee kinetic variables' associations with the knee injury and osteoarthritis outcome score (KOOS).

We found that all 4 software packages showed reasonably good meshing accuracies for clinical use. However, the range of errors inherent in the CT-image-based meshing process demands that caution should be taken in selecting and manipulating the software to avoid potential errors in specific clinical applications.

The external knee adduction moment (EKAM) is associated with knee osteoarthritis (OA) in many aspects including presence, progression, and severity of knee OA. Despite of its importance, there is a lack of EKAM estimation methods that can provide patients with knee OA real-time EKAM biofeedback for training and clinical evaluations without using a motion analysis laboratory. A practical real-time EKAM estimation method, which utilizes kinematics measured by a simple six degree-of-freedom goniome

Auto-tuning of robust PID Control is presented. To this end, we propose the equivalence condition between the modified TDC using sliding mode concept and the PID controller in a discrete-time domain. To realize auto-tuning of the PID control gains, we have synergistically combined the sliding mode concept and adaptive control. The desired error dynamics is described by using sliding mode concept, and the adaptive gain dynamics is proposed using the sliding variable. A leakage term is used for th

An accurate and robust impedance control technique is developed based on internal model control structure and time-delay estimation: the former injects desired impedance and corrects dynamics estimation error; the latter estimates and compensates the nonlinear dynamics of robot manipulators. Owing to the simple structure, the proposed control is designed without requiring entire dynamics computation or complex algorithms. The accuracy and robustness of the proposed control are verified using a t

This paper presents stability analysis and experimental results of the nonlinear bang-bang impact controller for multi-degree of freedom robot manipulators. Stability conditions have been derived based on the analysis in L/sub /spl infin// /sup n/ space and their physical interpretation has been given. The analysis shows that the stability of nonlinear bang-bang impact control depends on sampling time and the accuracy of inertia estimation. Stability is enhanced with the decrease of changes in t