Rank in Judo judo association. For a rank to be recognized, it must be registered with the national judo organization or the Kōdōkan. In Japan, the use of belt colors is related to the age of the student. Some clubs will only have black and white, others will include a brown belt for advanced kyū grades and at the elementary school level it is common to see a green belt for intermediate levels. In Europe the belt system is white, yellow, orange, green, blue, brown and black for both senior and junior practitioners. Judokas who have attained the 6th Dan may also use
Low-degree saturation Low-degree saturation In a scale-free network the degree distribution follows a power law function. In some empirical examples this power-law fits the degree distribution well only in the high degree region, however for small degree nodes the empirical degree-distribution deviates from it. See for example the network of scientific citations. This deviation of the observed degree-distribution from the theoretical prediction at the low-degree region is often referred as low-degree saturation. Typically the empirical degree-distribution deviates downwards from the power-law function fitted on higher order nodes, which means low-degree nodes are less frequent in real data than what is predicted by