【多选题】下列( )是 步进电机的特点 ?
C.
控制简单,开环,无须参数设计及调整,不存在稳定性问题;
D.
速度取于脉冲信号的频率,位移量取决于脉冲数。
【判断题】滞纳金或者提供纳税担保的,税务机关可以阻止其出境。( )
【判断题】若线性规划的原问题有无穷多个最优解时,其对偶问题也一定有无穷多个最优解。
【单选题】196 The project manager must receive reports and briefings from engineers, contracting officers, procurement personnel and marketing people. The project manager's communication dilemma is one of:
【判断题】若线性规划的原问题有无穷多个最优解时,其对偶问题也有无穷多个最优解。( )
【单选题】114 The project manager must receive reports and briefings from engineers, contracting officers, procurement personnel and marketing people. The project manager's communication dilemma is one of:
【单选题】工业机器人的发展经历了三个阶段,其中第三个阶段是?