Integrality Gaps of Integer Knapsack Problems
  We obtain optimal lower and upper bounds for the (additive) integrality gaps of integer knapsack problems. In a randomised setting, we show that the integrality gap of a "typical" knapsack problem is drastically smaller than the integrality gap that occurs in a worst case scenario. 
Iskander Aliev and Martin Henk and Timm Oertel
math.OC