There are some experiences that researcher come across quite number of time for very large networks in the initial samples such that they cannot finish the sampling procedure. Two solutions have been proposed and used by marine biologists which we discuss in this article: i) Adaptive cluster sampling based on order statistics with a stopping rule, ii) Restricted adaptive cluster sampling. Until...

Label each edge of a graph with a group element. Call the labels gains, and call the graph with this labeling a gain graph. A group expansion of an ordinary graph is an example of a gain graph. To construct one, replace each edge of a graph by several edges, one bearing as gain each possible value in a group. We introduce the concept of a group expansion of a gain graph. Then we find a formula ...