## UCGOII Consider a fir iite module M with exactly u find k different elements x1, x2, . . . , xk out of following conditions. elements. Suppose it is possible to the u ele:men:s of 34 satisfying the (i) Among tht: k(k -I) differences 4 -x1, rf t, r; t = 1, 2,. . . , k, just ni of the non-zero el
A note on construction of symmetrical PBIB designs
โ Scribed by P.S. Gill
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 319 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
In this note initial block technique hzs been used for construction of some cl=s of
3-associate PBIB designs, known as rectangular desigus.
Let A = MX S be the Cartesian produd of M and S, where .M = (a~, a lr. . . , qn_3 is an additive group of order m and S = (0, I,. . . , s -1). I& a,l' denote a typical element of A. The rectangular association scheme for the MS symbols of A is defined as a scheme in which two symbols qj and uJ' are called first associates if i = i'; second associates if j = j'; and third associates otherwise.
We define a rectangular PBIB design (to be denoted by RIB) as an arrangement of the 312s sy&ols of A in b blocks each of size k (ems) such that (i) every symbo1 occuxs at most once in a block,
๐ SIMILAR VOLUMES
In this note a method of construction of certain combinatorial designs is defined. This gives the solution of (121, 132, 60, 55, 27) which is marked as unknown by Kageyama [l].
Triangle-free quasi-symmetric 2-(v, k,k) designs with intersection numbers x, y; 01, are investigated. It is proved that k โฅ 2 yx -3. As a consequence it is seen that for fixed k, there are finitely many triangle-free quasi-symmetric designs. It is also proved that: k โค y( yx)+ x.
In this paper, a new class of partially balanced incomple'e block designs is constructed over an association scheme obtained from a finite projective gecmetry. Further, a general mrbt;s&3 for deriving a balanced incomplete block design from another one is given. [Z] RC Bose and T, Shimatnoto, ClasM
A blocking set of a design different from a 2-(ฮป+ 2, ฮป+ 1, ฮป) design has at least 3 points. The aim of this note is to establish which 2-(v, k, ฮป ) designs D with r โฅ 2ฮป may contain a blocking 3-set. The main results are the following. If D contains a blocking 3-set, then D is one of the following d