奇异线性二次指标最优控制问题LQ问题
singular linear quadratic LQ problem
常问问题
frequently asked question
Frequently asked questions
FAQ
态度问题问卷
attitude problem questionnarie
《升降机及电楼梯安全使用守则》
Code of Practice for Safe Use of Lifts and Escalators
多段楼梯
staircase with several flights
防烟楼梯间
smoke preventing staircase
smoke prevention stairwell
smoke proof staircase
Anti-smoke stair-half
smoke control-stair well