集装箱的装箱问题

给定一个集装箱，其长为L，宽为W和高为H，现有一批圆柱形木材，每根木材的长均为L，但是半径不同，设第i根木材半径为ri。问如何装箱，使得集装箱的空间利用率最高？-problem given a container, its length L, width W and H for high, existing batch of cylindrical wood and each timber are long L, but different radius, based i-radius of the wood-ri. Asked how crates, containers make maximum utilization of space?