Minimizing shutterings assembling time on construction sites can yield significant savings in labor costs and crane moves. It requires solving a pairing problem that optimizes the ability for the crane to move chains of shutterings as a whole when they can be later reused together to frame another wall of the site. In this paper, we show that this problem is NP-hard in the strong sense as well ...

This paper presents an original interactive analysis method consisting of mathematical calculation based on theoretical mechanics and mechanics of materials, and dynamics simulation for quantifying outrigger reaction forces of a kind of hydraulic mobile crane, aiming to avoid the eventualities during normal operation as far as possible, for example, tipping-over. First, a three dimensional dyna...

In this paper, we analyze the recurrence relations generalized from the Tower of Hanoi problem of the form T (n, α, β) = min1≤t≤n{αT (n− t, α, β)+β S(t, 3)}, where S(t, 3) = 2−1 is the optimal solution for the 3-peg Tower of Hanoi problem. It is shown that when α and β are natural numbers and α ≥ 2, the sequence of differences of T (n, α, β)’s, i.e., T (n, α, β) − T (n − 1, α, β), consists of n...

In order to meet the requirements of long range obstacle measurement of tower crane safety warning system and accurately estimate time of flight (TOF), an ultrasonic long range measurement system is designed and a mathematical model of echo envelope is established in this paper. Experimental data of long range obstacle measurement were collected and analyzed by using traditional threshold metho...