Let D be a statistical design consisting of v varieties on b blocks. We say it is binary if a variety occurs at most once on every block. For varieties p and q on blocks x and y respectively, we can obtain design D' from D by interchanging p and q (so p is on y and q is on x). We say that the exchange is binary if either x y, or p q, or: q not on x and p not on y. If D is binary then D' is also...

Chromosomal interchanges, or reciprocal translocations, in maize are of primary interest because of the opportunities they offer for the study of chromosome behavior and crossing over. The great volume of work which has been done on crossing over and on translocations in Drosophila has yielded an abundance of statistical data on crossing over and chromosome distribution. For this type of work D...

We initiate the study of sorting permutations using prefix block-interchanges, which exchange any a permutation with another non-intersecting interval. The goal is to transform given into identity as few such operations possible. give 2-approximation algorithm for this problem, well 4/3-approximation simple permutations; we prove tight lower and upper bounds on corresponding distance; bound lar...

Signalized diamond interchanges are pairs of ramp intersections characterized by interlocked left turns and relatively close spacing. This paper describes a series of performance measures derived from high-resolution signal controller event data that can be used to optimize the internal phase sequence and offset to improve traffic flows within diamond interchanges and to qualitatively and quant...

String theory requires two kinds of loop expansion: classical (α ′) world-sheet loops with expansion parameter < T > where T is a modulus field, and quantum (¯ h) spacetime loops with expansion parameter < S > where S is the dilaton field. Four-dimensional string/string duality (a corollary of ten-dimensional string/fivebrane duality) interchanges the roles of S and T and hence interchanges cla...

77 THIS FEATURE PRESENTS A RELAtively unique concept for urban arterial highway interchanges. The interchange has been named the Echelon Interchange because of its symmetrical, but offset, pair of two-phase one-way pair intersections—one elevated over the other. An observer1 noted that the interchange resembled a flying formation used by the U.S. Navy Flight Demonstration Team, the “Blue Angels...

To test quantitatively whether there are systematic chromosome-chromosome associations within human interphase nuclei, interchanges between all possible heterologous pairs of chromosomes were measured with 24-color whole-chromosome painting (multiplex FISH), after damage to interphase lymphocytes by sparsely ionizing radiation in vitro. An excess of interchanges for a specific chromosome pair w...

Consider the following optimization problem: given two strings over the same alphabet, transform one to another by a succession of interchanges of two elements. In each interchange the two participating elements exchange positions. An interchange is given a weight that depends on the distance in the string between the two exchanged elements. The object is to minimize the total weight of the int...