图书被借概率随时间递减倍速原理及其在图书剔旧的应用

Law of To-be-Borrowed Books Decreasing Probability and Its Application in Book Weeding

图书的被借概率应遵从随时间递减原理:将时间轴等分成无穷可列个时间段,并设一书在第一个时间段上具有最大的被借概率Pmax,则其在任一时间段上的被借概率必为其在前一时间段上的被借概率的(1-Pmax)倍。给出将该原理应用于图书剔旧时的估值,并讨论了该原理与普赖斯文献老化定律的区别与联系。

The probability of a book to be borrowed should abide by the law as follows ： if we divide the long unlimited time into millions and thousands of same periods and assume that a book would have a maximum probability Pmax to be borrowed in the first period, we can then conclude that in any period the prob- ability of those to be borrowed must be as（1-Pmax） multiples as that in the preceding one. In the article we deduce the approximation of Pmax, and discuss the difference as well as the association of the law with Prince Literature Obsolescence Law.