Block Pulse Function (BPF) is applied in analysis and synthesis of optimal control for PWM systems, and a piecewise constant solution is obtained;

块脉冲函数（BPF）用于PWM系统的分析及最优控制，获得分段恒定解；

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Morris said he was in "constant communication" with the ECB to find a "proactive solution with some flexibility" but he favoured developing an English alternative that would compensate the leading players for missing out on the riches on offer in the sub-continent.

BBC: England stars 'want India chance'

We are in constant consultation with our Russian counterparts and partners, and with other allies and partners who are interested in a positive solution to Libya so that the Libyan people can decide their own future.

WHITEHOUSE: Press Briefing