说明：  多产品多船种航速可变的 海运库存路径问题的研究
(This paper analyzes the research of the problem of the optimization of Marine inventory path by China and foreign countries. There have been a lot of studies done by scholars on the route of shipping inventory abroad, and some have gained some success. However, domestic research in this respect is rarely involved, almost all scholars to study on inventory path stays in land transportation, rarely involves the Marine transport, and about this aspect of the research in China is also only stay in theoretical research stage, still at the preliminary stage. So this article to our country under the background of current research in the inventory routing problem of shipping, for in-depth research in this aspect in our country, this paper studies the specific content from the following several aspects.)