Picard P
Math Biosci. 1989 May;94(1):45-85. doi: 10.1016/0025-5564(89)90072-2.
Two models are propounded on the general setting of the first Nåsell-Hirsch model for helminthic infections. They differ from it in the two processes of transmission of the infection, which are treated dissymmetrically. In each model only one of these processes will be deterministic, instead of both as in the Nåsell-Hirsch case, the other process being kept fully stochastic. These new models lead to results that show a general agreement with those of Nåsell and Hirsch but also some interesting differences.
针对蠕虫感染的首个纳塞尔-赫希模型的一般设定，提出了两种模型。它们在感染传播的两个过程上与该模型不同，这两个过程的处理方式不对称。在每个模型中，这些过程只有一个是确定性的，而不像纳塞尔-赫希模型那样两个都是确定性的，另一个过程则完全保持为随机的。这些新模型得出的结果与纳塞尔和赫希的结果总体一致，但也存在一些有趣的差异。
