Purpose: The time required by the algorithms for general layouts to solve the large-scale two-dimensional cutting problems may become unaffordable. So this paper presents an exact algorithm to solve above problems. Design/methodology/approach: The algorithm uses the dynamic programming algorithm...

Background: Bitcoin system, when more than 51% computing power is controlled by a single node, the block chain can be distorted maliciously. This is called 51% attack which is a well-known potential risk that could destroy the Bitcoin system. Method: The paper proves that under the current...