We deal with the unweighted and weighted enumerations of lozenge tilings of a hexagon with side lengths a; b + m; c; a + m; b; c + m, where an equilateral triangle of side length m has been removed from the center. We give closed formulas for the plain enumeration and for a certain (?1)-enumeration of these lozenge tilings. In the case that a = b = c, we also provide closed formulas for certain...

Wolfmann [Wolfmann, 1992] introduced the idea of ZCZ binary sequences with the so-called almost perfect sequences, which have one non-zero off-peak autocorrelation value. Non-binary ZCZ sequences over roots of unity were first constructed by Suehiro [Suehiro, 1994]. Other types of ZCZ sequences have been constructed based on the existence of complementary pairs [Suehiro, 1994][Fan, 1999a][Matsu...

Abstract Meinertsen’s unifier is discussed on the background of Aristotle’s distinction between four kinds unity. It argued that Meinertsen combines two different unity exclude each other. Only first meaning seems to be relevant for unifier. But this applies literally only spatial complexes. Its application states affairs problematic because they are mostly not spatial. also in sense requires a...

We prove that the triviality of the Galois action on the suitably twisted odd-dimensional étale cohomogy group with finite coefficients of an absolutely irreducible smooth projective variety implies the existence of certain primitive roots of unity in the field of definition of the variety. This text was inspired by an exercise in Serre’s Lectures on the Mordell–Weil theorem.

We study block decoupling of linear multivariable systems under unity-feedback configuration. We consider plants which have unstable pole-zero coincidences and give necessary and sufficient conditions for the existence of the block decoupling controllers. The conditions are particularly simple for plants with only simple unstable pole-zero coincidences. An illustrative example is given.

Let E be an elliptic curve, and let Ln be the Kummer extension generated by a primitive pnth root of unity and a pn-th root of a for a fixed a ∈ Q − {±1}. A detailed case study by Coates, Fukaya, Kato and Sujatha and V. Dokchitser has led these authors to predict unbounded and strikingly regular growth for the rank of E over Ln in certain cases. The aim of this note is to explain how some of th...

We consider the use of generalized Ding-Helleseth cyclotomy to design sequences over the finite field of order four. Using generalized cyclotomic classes of order four we obtain the family of balanced sequences of odd period with high linear complexity. Also we present a method of constructing sequences with high linear complexity and arbitrary even period over the finite field of order four. T...

Let K be a cyclic Galois extension of degree p over a field F containing a primitive pth root of unity. We consider Galois embedding problems involving Galois groups with common quotient Gal(K/F ) such that corresponding normal subgroups are indecomposable Fp[Gal(K/F )]modules. For these embedding problems we prove conditions on solvability, formulas for explicit construction, and results on au...

Let K be a cyclic Galois extension of degree p over a field F containing a primitive pth root of unity. We consider Galois embedding problems involving Galois groups with common quotient Gal(K/F ) such that corresponding normal subgroups are indecomposable Fp[Gal(K/F )]modules. For these embedding problems we prove conditions on solvability, formulas for explicit construction, and results on au...