In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The pro...In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The procedure was to perform controlled steering maneuver by right hand in a driving simulator, and based on analyzing the EMG data with steering force in the steering wheel plane, the function was identified. It was found that muscle function depends strongly on both steering rotation and steering torque directions. In clockwise steering, the long head of triceps brachii was the prime mover and an important contributor to clockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. In contrast, in counterclockwise steering, the anterior, middle and posterior deltoid, the clavicular portion of the pectoralis major and infraspinatus were the prime movers and also the important contributors to counterclockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. We conclude that the prime movers are primarily a consequence of steering direction, while the stabilizers or fixators are primarily constant. These results can be used to improve the neuromuscular model and estimate the steering comfort of driver.展开更多
We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit couplin...We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit coupling.We show that in the presence of weak external magnetic fields, some basic properties of a persistent spin helix state,including the dispersion relation between the decay time and the magnitude of the wavevector, the maximum decay time and the value of the characteristic magnitude of the wavevector at which the maximum decay time occurs, will all depend sensitively on the directions of applied external magnetic fields.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51005133)the National High Technology Research and Development Program of China (Grant No. 2011AA11A244)Special Financial Grant of the National Science Foundation for Post-doctoral Scientists of China (Grant No. 201104098)
文摘In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The procedure was to perform controlled steering maneuver by right hand in a driving simulator, and based on analyzing the EMG data with steering force in the steering wheel plane, the function was identified. It was found that muscle function depends strongly on both steering rotation and steering torque directions. In clockwise steering, the long head of triceps brachii was the prime mover and an important contributor to clockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. In contrast, in counterclockwise steering, the anterior, middle and posterior deltoid, the clavicular portion of the pectoralis major and infraspinatus were the prime movers and also the important contributors to counterclockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. We conclude that the prime movers are primarily a consequence of steering direction, while the stabilizers or fixators are primarily constant. These results can be used to improve the neuromuscular model and estimate the steering comfort of driver.
基金Supported by the National Natural Science Foundation of China under Grant No.10874049
文摘We study theoretically the effect of weak external magnetic fields on persistent spin helix states in semiconductor two-dimensional electron gases with both Rashba and linear-in-momentum Dresselhaus spin-orbit coupling.We show that in the presence of weak external magnetic fields, some basic properties of a persistent spin helix state,including the dispersion relation between the decay time and the magnitude of the wavevector, the maximum decay time and the value of the characteristic magnitude of the wavevector at which the maximum decay time occurs, will all depend sensitively on the directions of applied external magnetic fields.
