The purpose of this study was to identify changes in ankle range of motion and passive mechanical properties of the muscle-tendon unit after dynamic stretching. 12 healthy subjects participated in this study. Displacement of the muscle-tendon junction was measured using ultrasonography while the ankle was passively dorsiflexed at 1°/sec to its maximal dorsiflexion angle. Passive torque was also measured using an isokinetic dynamometer. Measurements were conducted pre-intervention, immediately after the intervention and 5, 10, 15 and 30 min post-intervention. The dynamic stretching consisted of four 30-s periods of ankle dorsiflexion and plantarflexion. Ankle range of motion was significantly increased immediately (from 18.3±1.8° to 21.4±1.7°) and 10 min (20.9±1.9°) after dynamic stretching, but this change disappeared within 15 min. However, stiffness of the muscle-tendon unit and displacement of the muscle-tendon junction at the submaximal dorsiflexion angle did not differ between the experimental conditions. These results demonstrate that dynamic stretching by contracting an antagonist muscle group increases ankle range of motion temporarily without changing the passive mechanical properties of the muscle-tendon unit. The increased range of motion of the ankle after dynamic stretching might be caused by enhanced stretch tolerance.

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In this paper, we consider the optimal servo design problems of the systems with input norm constraints. We propose a new method to design nonlinear optimal servo controllers satisfying the input norm constraints. This method is based on solving Hamilton-Jacobi equations via center-stable manifold theory. We verify the effectiveness of the proposed method by a computer simulation by using Permanent Magnet Synchronous Motor.

A new self‐alignment process technology SATURN (self alignment technology utilizing reserved nitride) has been developed in which the selective oxidation of polysilicon and the nitride films in this oxidation process are used for a number of objectives with a view to improve the operating speed of the bipolar devices. This method is characterized by the control of the emitter stripe width by the side wall spacer film thickness and the control of the distance between the emitter and the external base by the selective oxide film thickness are carried out independently. A process of optimization based on the forementioned control was carried out so that the small transistor with an emitter stripe width of 0.5 μm and a distance of 0.35 μm between the emitter contact and the base contact was realized. This resulted in a current gain of 66 and a cutoff frequency of 12 GHz. Further, this transistor was applied in the ECL circuit which resulted in the performance with the minimum propagation delay time of 88 ps in an inverter gate and the maximum dividing frequency of 3.5 GHz in a 1/8 divider.

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