Operator angle-action variables are studied in the frame of the SU(2) algebra, and their eigenstates and coherent states are discussed. The quantum mechanical addition of actionangle variables is shown to lead to a novel non commutative Hopf algebra. The group contraction is used to make the connection with the harmonic oscillator. Presented at the ”Harmonic Oscillators” Workshop University of ...

BACKGROUND Previous studies have indicated that the demands placed on the medial ulnar collateral ligament of the elbow when it is subjected to valgus torque during throwing exceed its failure strength, which suggests the necessary dynamic contribution of muscle forces. We hypothesized that the flexor-pronator mass assists the medial ulnar collateral ligament in stabilizing the elbow against va...

Abstract Pore diameter and arc thickness of propellant are decided by the extrusion mold parameters. Mold needles deform during propellant’s forming process because material’s high viscosity needle’s flexibility, which affects quality products. Based on fluid-structure interaction, we simulated 19-hole nitroguanidine studied influence law structural parameters deformation needles. The results s...

We propose to estimate rule-based myocardial fiber model (RBM) parameters from DT-MRI, with the goal of personalizing the fiber architecture for cardiac simulations. The RBM is based on a space-dependent angle distribution on the heart surface and then extended to the whole domain through an harmonic lifting of the fiber vectors. For the angles estimation we use a static Unscented Kalman Filter...

Aiming at the nonlinear expansion/contraction drive problem between different cables in multi-joint cable mechanisms, a mechanical method based on non-circular gear was proposed, which could replace servo-sensing control system and minimize system’s complexity cost. A single-degree-of-freedom (DOF) bending mechanism constructed with several T-shaped components cross-shaped components. The princ...

Skeletal muscles power body movement by converting free energy of ATP hydrolysis into mechanical work. During the landing phase of running or jumping some activated skeletal muscles are subjected to stretch. Upon stretch they absorb body energy quickly and effectively thus protecting joints and bones from impact damage. This is achieved because during lengthening, skeletal muscle bears higher f...

BACKGROUND Anismus is thought to be a cause of chronic constipation by producing outlet obstruction. The underlying mechanism is paradoxical contraction of the anal sphincter or puborectalis muscle. However, paradoxical sphincter contraction (PSC) also occurs in healthy controls, so anismus may be diagnosed too often because it may be based on a non-specific finding related to untoward conditio...

BACKGROUND The high physical demands placed on the upper extremity during manual wheelchair propulsion can lead to pain and overuse injuries that further reduce user independence and quality of life. Seat position is an adjustable parameter that can influence the mechanical loads placed on the upper extremity. The purpose of this study was to use a musculoskeletal model and forward dynamics sim...

Although activity of the rectus femoris (RF) differs from that of the other synergists in quadriceps femoris muscle group during physical activities in humans, it has been suggested that the activation pattern of the vastus intermedius (VI) is similar to that of the RF. The purpose of present study was to examine activation of the VI during isometric hip flexion. Ten healthy men performed isome...