增长型供应链演化网络的度分布

The distribution of the evolution network with growth supply chain

增长型供应链演化网络是一种除了具有无标度网络模型的特性外,同时还具有根据路径可行性连向度值小的节点的特征.随着时间增长网络的尺度不断增大.用主方程法计算反应网络拓扑结构信息的度分布,计算结果具有幂律特征且幂指数在2.5左右浮动.通过计算机模拟得出,度分布和度值的图像突然有一向上的尾巴;这表明当时间很大时,网络尺度也很大时,新加入的节点都连向度值大的节点,路径择优所起的作用很小;这恰恰反映了供应链演化网络集团化程度比无标度网络高.与现实的供应链系统很好的吻合.

The evolution network of growth supply chain network has not only the characteristic of the scale-free network model, but also has a feature which a new node attach with an old node of the smaller degree based on the path preferential attachment. Over time increasing the scale ofthe network is growth. The degree distribution that informs the topology of the network is calculated with master equation method. The result has the power law exponent floating around 2.5. It is obtained by computer simulation. The image of distribution and the degree value has been the tail suddenly directing up- ward. When the time is long and the network is also a great scale, it is indicated that newly added nodes are connected nodes with larger degree value and that the role of the path preferential attachment is a small merit. This precisely reflects the level group of this network is higher than level group of the scale-free network. It is in good agreement with reality.