منابع مشابه
Wilson’s theorem for block designs
Steiner systems S(2, k, v) For k ≥ 3, a Steiner system S(2, k, v) is usually defined as a pair (V,B), where V is a set of cardinality v of points and B is a set of k-element subsets of V , usually called blocks, or lines if the system has some geometric significance, with the property that each pair of points is contained in precisely one block. For example, to construct a Steiner system S(2, 3...
متن کاملTesting block subdivision algorithms on block designs
Integrated land use-transportation models predict future transportation demand taking into account how households and firms arrange themselves partly as a function of the transportation system. Recent integrated models require parcels as inputs and produce household and employment predictions at the parcel scale. Block subdivision algorithms automatically generate parcel patterns within blocks....
متن کاملOn directed designs with block size five
In a t-(v, k, λ) directed design the blocks are ordered k-tuples and every ordered t-tuple of distinct points occurs in exactly λ blocks (as a subsequence). We study t-(v, 5, 1) directed designs with t = 3 and t = 4. In particular, we construct the first known examples, and an infinite class, of 3-(v, 5, 1) directed designs, and the first known infinite class of 4-(v, 5, 1) directed designs.
متن کاملOn the number of indecomposable block designs
A t-(v; k;) design D is a system (multiset) of k-element subsets (called blocks) of a v-element set V such that every t-element subset of V occurs exactly times in the blocks of D. A t-(v; k;) design D is called inde-composable (or elementary) if and only if there is no subsystem which is a t-(v; k; 0) design with 0 < 0 <. It is known that the number of inde-composable designs for given paramet...
متن کاملRemarks on Balanced Incomplete Block Designs
Proof. Assume the hypothesis and the falsity of either conclusion. Construct matrix A of 2x + 2 rows and 4x+4 columns, with entries + 1 and — 1. The first column contains exclusively +1, and the second column — 1. Set up one-to-one correspondences between rows of A and elements of D ; between columns other than the first two of A and blocks of D. Enter +1 if the element is contained in the bloc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 1986
ISSN: 0012-365X
DOI: 10.1016/0012-365x(86)90164-0