关于一个定义的解释，请求帮忙！

skysophie

Definitions.-An arrangement of v objects (called treatments) in b sets
8 J  c* u  U- {+ @; X' U6 ?(called blocks) will be called a pairwise balanced design of index unity and type
(v; ki, k2, .. ., ki) if each block contains either k1, k2, .. ., or km treatments which
: J2 p  }5 U- f4 iare all distinct (k, < v, k, $ kj), and every pair of distinct treatments occurs exactly
" Q6 B3 F1 c9 {+ B9 cin one block of the design. If the number of blocks containing k, treatments is
b,, then clearly  b = A bi, v(v-1) = i biki(k -1)。。。
" _$ {1 p3 k* h6 v* _) @& T$ c: K
谁能帮我解释一下，可以举个简单的例子。。谢谢！~

角凳

是告诉我们这是哪个领域的么？？